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The preliminary design of an aquaculture facility using systems analysis techniques : a British Columbia… MacKinlay, Don D. 1984

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THE PRELIMINARY DESIGN OF AN AQUACULTURE FACILITY  USING SYSTEMS ANALYSIS TECHNIQUES: A BRITISH COLUMBIA CASE STUDY. B. Sc., U n i v e r s i t y of B r i t i s h Columbia, 1974 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE IN THE FACULTY OF GRADUATE STUDIES I n t e r d i s c i p l i n a r y Program With The Departments Of Bi o - R e s o u r c e E n g i n e e r i n g , A g r i c u l t u r a l M e c h a n i c s , and The I n s t i t u t e Of Animal Resource E c o l o g y . We a c c e p t t h i s t h e s i s as c o n f o r m i n g t o the r e q u i r e d s t a n d a r d THE UNIVERSITY OF BRITISH COLUMBIA May, 1984 f £ ) Donald Drew M a c K i n l a y , 1984 by Don D. M a c K i n l a y In p r e s e n t i n g t h i s t h e s i s i n p a r t i a l f u l f i l m e n t o f the requirements f o r an advanced degree a t the U n i v e r s i t y o f B r i t i s h Columbia, I agree t h a t the L i b r a r y s h a l l make i t f r e e l y a v a i l a b l e f o r r e f e r e n c e and study. I f u r t h e r agree t h a t p e r m i s s i o n f o r e x t e n s i v e copying o f t h i s t h e s i s f o r s c h o l a r l y purposes may be granted by the head o f my department o r by h i s or her r e p r e s e n t a t i v e s . I t i s understood t h a t copying or p u b l i c a t i o n of t h i s t h e s i s f o r f i n a n c i a l g a i n s h a l l not be allowed without my w r i t t e n p e r m i s s i o n . Department o f *Q/o 'iJfSQfCe The U n i v e r s i t y of B r i t i s h Columbia 1956 Main Mall Vancouver, Canada V6T 1Y3 i i ABSTRACT A method i s p r e s e n t e d f o r the s e l e c t i o n of a c o n c e p t u a l d e s i g n of an a q u a c u l t u r e f a c i l i t y u s i n g a systems approach whereby many a l t e r n a t i v e s f o r each f a c i l i t y component are gen e r a t e d and e v a l u a t e d b e f o r e s e l e c t i o n and d e t a i l e d d e s i g n a r e c a r r i e d o u t . I n c l u d e d a re e x t e n s i v e l i t e r a t u r e r e v i e w s of d e s i g n and o p e r a t i o n of a q u a c u l t u r e f a c i l i t i e s and m a t h e m a t i c a l modeling methodology f o r a n a l y s i n g the p r o d u c t i o n of a q u a t i c organisms. The method i s a p p l i e d t o the d e s i g n of a f a c i l i t y t o f i t i n t o an e x i s t i n g c a t t l e r anch i n the dry i n t e r i o r of B r i t i s h Columbia near N i c o l a Lake. The two o p e r a t i o n s ( a g r i c u l t u r e and a q u a c u l t u r e ) a re seen as m u t u a l l y b e n e f i c i a l : the ranch can p r o v i d e husbandry and t e c h n i c a l manpower, shared machinery and equipment and l o a n c o l l a t e r a l t o the f i s h farm; and the f i s h farm can p r o v i d e income d i v e r s i f i c a t i o n and waste n u t r i e n t r i c h water f o r i r r i g a t i o n t o the r a n c h . The chosen d e s i g n was t h a t of an i n t e n s i v e c u l t u r e t r o u t farm u s i n g g r a v i t y f e d s u r f a c e water from Moore Creek f e e d i n g i n t o above ground p l a s t i c raceways (10,000 t r o u t per raceway). The raceways are a r r a n g e d down the n a t u r a l s l o p e of the l a n d w i t h s e r i a l r e c y c l i n g of the w a t e r , b i o l o g i c a l f i l t r a t i o n a f t e r e very t h i r d reuse and r e - a e r a t i o n b e f o r e e n t e r i n g each raceway. Gross economic a n a l y s i s i n d i c a t e s t h a t a l t h o u g h some t r o u t farm s i z e s would not be p r o f i t a b l e , a v e r y s m a l l o p e r a t i o n (one or two raceways) would pay f o r i t s e l f and a mo d e r a t e l y l a r g e o p e r a t i o n ( s i x t o ten raceways) would produce a good r e t u r n on i n v e s t m e n t . M a t h e m a t i c a l models f o r f i s h , i n v e r t e b r a t e and a l g a l growth and f i s h r e s p i r a t i o n were adapted to the d e s i g n p r o c e s s by i n c o r p o r a t i n g them i n t o i n t e r a c t i v e computer programs i n the BASIC language f o r the APPLE microcomputer. C a l c u l a t i o n p r o c e d u r e s f o r the d e s i g n of s o l a r and c o n v e n t i o n a l h e a t i n g and b i o l o g i c a l f i l t r a t i o n of the p r o c e s s water, p i p e l i n e d e s i g n s e l e c t i o n , and c a p i t a l and o p e r a t i o n s c o s t i n g were developed as f o r m a t t e d m a t r i c e s on a commercial s p r e a d s h e e t program so t h a t many o p t i o n s c o u l d be e v a l u a t e d w i t h ease. A t a b u l a r e v a l u a t i o n format was d e v e l o p e d t o q u a n t i t a t i v e l y rank the s u i t a b i l i t y of v a r i o u s p o t e n t i a l a l t e r n a t i v e d e s i g n c o n f i g u r a t i o n s f o r each component of the o v e r a l l system t o a i d i n a l t e r n a t i v e s e l e c t i o n . The s t e p s r e q u i r e d t o t u r n t h i s c o n c e p t u a l d e s i g n i n t o a w o r king p i l o t p l a n t l e a d i n g to a v i a b l e p r o d u c t i o n f a c i l i t y a r e o u t l i n e d , a l o n g w i t h the a r e a s of g r e a t e s t u n c e r t a i n t y i n the d e s i g n . i v TABLE OF CONTENTS A b s t r a c t i i T a b l e of C o n t e n t s i v L i s t of F i g u r e s x i L i s t of T a b l e s x i v L i s t of Formulae x v i Acknowledgements x v i i i I . Background 1 1 . I n t r o d u c t i o n 2 A. J u s t i f i c a t i o n 2 B. Problem F o r m u l a t i o n 7 a. I n t r o d u c t i o n 7 b. H y p o t h e s i s Statement 8 c. A n a l y s i s O b j e c t i v e s 10 C. T h e s i s O u t l i n e 11 I I . R e l a t e d Research 13 2. A q u a c u l t u r a l O p e r a t i o n s 14 A. G e n e r a l 14 a. Purpose 14 b. H i s t o r y 15 c. Importance 18 B. P r i n c i p l e s of A q u a c u l t u r e 20 a. Squeeze 20 b. Seed And Breed 21 c. Feed 24 d. Growth 25 e. H e a l t h 26 V C. Canadian A q u a c u l t u r e 29 a. S t a t u s . 29 b. P o l i c y 31 c. B. C. P o t e n t i a l 33 D. S almonid C u l t u r e 36 a. I n t r o d u c t i o n 36 b. E x t e n s i v e C u l t u r e 37 c. I n t e n s i v e C u l t u r e 38 E. Other F i s h e s 40 F. Lower T r o p h i c C u l t u r e 43 3. A q u a c u l t u r a l System Design 46 A. Def i n i t i o n s 46 a. G e n e r a l 46 b. S c a l e 47 B. D e s i g n P r o c e s s 49 a. Approaches 49 b. O r i e n t a t i o n 53 c. B i o l o g i c a l C r i t e r i a 54 d. F i s h C u l t u r e O p e r a t i o n s 55 e. Economic F a c t o r s 56 C. P r o c e s s Requirements 61 a. T e c h n i c a l S u i t a b i l i t y 61 b. Flow Requirements 66 c. Space Requirements 69 d. Feed Requirements 70 D. E n c l o s u r e s 72 a. I n t r o d u c t i o n 72 v i b. E x t e n s i v e C u l t u r e 73 c. Cage C u l t u r e 75 d. Pond C u l t u r e 78 e. Raceway C u l t u r e 82 f. Salmonid F a c i l i t i e s 86 E. Post R e a r i n g 93 a. I n t r o d u c t i o n . . 93 b. H a r v e s t 93 c . P r o c e s s i n g 94 d. Storage 96 e. T r a n s p o r t 97 F. Lower L e v e l C u l t u r e 98 a. I n t r o d u c t i o n 98 b. P r i m a r y P r o d u c e r s 101 c. Secondary P r o d u c e r s 103 G. Water Reuse 106 a. J u s t i f i c a t i o n 106 b. P h y s i c a l - C h e m i c a l F i l t r a t i o n 107 c. B i o l o g i c a l F i l t r a t i o n 108 d. A e r a t i o n 110 e. R e c y c l i n g Systems 113 H. Water C o n t r o l and Measurement 114 a. I n t r o d u c t i o n 114 b. Flow Measurement 115 c. Flow C o n t r o l 116 d. Temperature C o n t r o l 118 4. M o d e l l i n g A q u a t i c P r o d u c t i o n 121 v i i A. Approaches t o Or g a n i c Growth 121 B. A q u a t i c P r o d u c t i o n 127 a. F a c t o r s I n v o l v e d 127 b. M o d e l l i n g 129 C. A l g a l Growth . 131 a. L i g h t 132 b. N u t r i e n t s 134 c. R e s p i r a t i o n 135 d. C a r r y i n g C a p a c i t y 136 D. Zooplankton Growth 137 a. F a c t o r s I n v o l v e d 137 b. M o d e l i n g 139 E. F i s h Growth 140 a. F a c t o r s A f f e c t i n g Growth 140 b. Models 143 F. A b i o t i c F a c t o r s 146 I I I Methodology 149 5 Systems A n a l y s i s Methods 150 A. G e n e r a l 1 50 a. D e f i n i t i o n s 150 b. Approach 151 B. P r o c e d u r e O u t l i n e 153 a . Overview 153 b. Problem D e f i n i t i o n 157 c . O b j e c t i v e s 157 d. A l t e r n a t i v e G e n e r a t i o n 159 e. A l t e r n a t i v e E v a l u a t i o n 159 v i i i f . Dec i s i o n 160 6. M o d e l l i n g Methods 162 A. Types of Models ....162 B. M o d e l l i n g P r o c e s s 163 C. F l o w c h a r t i n g 166 IV. R e s u l t s 176 7. S i t e C h a r a c t e r i s t i c s 177 A. L o g i s t i c s 177 B. E n v i r o n m e n t a l 183 8. Systems A n a l y s i s 185 A. Problem D e f i n i t i o n 185 B. O b j e c t i v e s D e f i n e d 187 C. Measures of E f f e c t i v e n e s s ....188 a. Lack of A g r i c u l t u r a l I n t e r f e r e n c e 189 b. Degree of A q u a t i c P r o d u c t i o n 190 c. Economic V i a b i l i t y 191 D. G e n e r a t i o n of A l t e r n a t i v e s 192 a. Framework of A q u a t i c P r o d u c t i o n 192 E. E v a l u a t i o n of A l t e r n a t i v e s 194 a. T a b u l a r E v a l u a t i o n Overview 194 b. Water Source 196 c. Water Conveyance 198 d. Volume Water Use 200 e. Water Reuse 201 f. Water Treatment 204 g. F i s h Type 213 h. F i s h E n c l o s u r e 214 i x i . F i s h Food 215 j . Energy Source 220 k. Energy I n t e n s i t y 222 1. Labour I n t e n s i t y 223 F. Conceptual Design 224 a. O u t l i n e 224 b. System S i z i n g 227 c. Economic A l t e r n a t i v e s 233 9. Model Development 241 A. Problem D e f i n i t i o n 241 B. O b j e c t i v e s 242 C. Measures of E f f e c t i v e n e s s 243 D. Generation and S e l e c t i o n of A l t e r n a t i v e s 244 a. Mathematical A l t e r n a t i v e s 244 b. Computer A l t e r n a t i v e s 245 c. Common Program Features 246 E. F i s h Model 249 a. Black Box 249 b. Mathematics 251 c. Computer Outputs 255 F. I n v e r t e b r a t e Model 259 a. Black Box 259 b. Mathematics 260 c. Computer Outputs 262 G. Algae Model 266 a. Black Box 266 b. Mathematics 267 X c. Computer Outputs 269 V. D i s c u s s i o n 273 10. A q u a c u l t u r e System 274 A. Summary 274 B. L i m i t a t i o n s and F u t u r e Research 275 C. C o n c l u s i o n s 279 1 1 . Use Of Models 281 A. Summary 281 B. L i m i t a t i o n s and F u t u r e Research 283 C. C o n c l u s i o n s 285 12. Design Approach 286 A. Summary 286 B. L i m i t a t i o n s And F u t u r e Research 287 C. C o n c l u s i o n 289 L i t e r a t u r e C i t e d 290 Appendix A. Computer Program L i s t i n g s 319 1 . F i s h Model 320 2. I n v e r t e b r a t e Model 324 3. A l g a e Model 328 4. G r a p h i c s Package 332 Appendix B. M u l t i - T r o p h i c C u l t u r e A n a l y s i s 337 1 . O u t l i n e 337 2. E v a l u a t i o n s 339 x i LIST OF FIGURES 1. S t a t e of World A f f a i r s 3 2. V a r i o u s F i s h Egg I n c u b a t o r s 24 3. P o l y c u l t u r e Example 27 4. I n t e r r e l a t i o n s h i p of D i s e a s e C a u s i n g F a c t o r s 27 5. F a c i l i t y Design S c i e n c e I n t e r r e l a t i o n s h i p s 50 6. C i r c u l a r Raceways 84 7. R e c t a n g u l a r Raceways 88 8. P l a s t i c L i n e d Raceways 89 9. An Example of V e r t i c a l Raceway Use 91 10. Stream Improvement 92 11. L e v e l C o n t r o l D e v i c e s 117 12. An Example of a Temperature S e l e c t i o n D e v i c e ....120 13. V a r i o u s Model E q u a t i o n Types 123 14. G r a p h i c a l C a l c u l a t i o n s of H a l f S a t u r a t i o n C o n s t a n t s f o r N i t r a t e and Phosphate 127 15. Web C h a r t of an A q u a t i c Ecosystem 128 16. The E f f e c t of Temperature and L i g h t I n t e n s i t y on P h o t o s y n t h e s i s 133 17. F l o w c h a r t of Systems A n a l y s i s P r o c e d u r e 155 18. D e c i s i o n F l o w c h a r t 167 19. L i n e Drawing F l o w c h a r t 168 20. Multi-component System 169 21. Water F l o w c h a r t 169 22. I n s t i t u t i o n a l and O r g a n i z a t i o n a l P l a n n i n g F l o w c h a r t ..170 23. Computer Program A l g o r i t h m F l o w c h a r t 172 24. P l a n n i n g PERT O u t l i n i n g A q u a c u l t u r a l Development i n the U.S.A 174 25. O u t l i n e of D e t a i l e d PERT Used i n the Management of a D a n i s h T r o u t Farm 175 26. L o c a t i o n Map of the Study Area 178 27. Photos of the Guichon Ranch 179 28. R e l a t i o n s h i p Diagram of F a c t o r s A f f e c t i n g P r o j e c t P r o d u c t i o n 1 93 29. O p e r a t i o n s P r o c e s s C h a r t f o r F a c i l i t y 227 30. Reverse Growth of T r o u t over Growing Season 228 31. C o n c e p t u a l Layout Diagram of P a r t of a " S e r i e s Two" C u l t u r e System 231 32. I l l u s t r a t i o n s of P o s s i b l e Design D e t a i l s f o r the I n t a k e and Pre-Raceway A e r a t i o n Columns 235 33. G e n e r a l S i m u l a t i o n Program Layout . 247 34. Comparison of Recorded and F o u r i e r Generated Temperatures f o r the N i c o l a R i v e r Above N i c o l a Lake ...249 35. B l a c k Box Diagrams of Main Model Components 251 36. F i s h Growth Rate R e l a t i o n s h i p s i n the Model t o the Main D r i v i n g V a r i a b l e s 253 37. F i s h M e t a b o l i c Rate R e l a t i o n s h i p s 255 38. F i s h Program Screens 256 39. F i s h Weight, Flow R e q u i r e d and Space R e q u i r e d Graphs f o r the Guichon P r o j e c t 258 40. Growth Rate, M e t a b o l i c Rate and Number of F i s h f o r the Guichon P r o j e c t 259 41. I n v e r t e b r a t e Model Growth Rate R e l a t i o n s h i p s 262 x i i i 42. I n v e r t e b r a t e Program Screens 263 43. I n v e r t e b r a t e S i m u l a t i o n Output 265 44. A l g a l Model Growth Rate R e l a t i o n s h i p s 269 45. A l g a l Program Screens 270 46. A l g a l S i m u l a t i o n Output 272 x i v LIST OF TABLES 1 . Steps In F a c i l i t y D e s i g n 52 2. F a c t o r s A f f e c t i n g the P r o d u c t i v i t y of T r o u t and Salmon R a i s i n g F a c i l i t i e s 63 3. Steps i n Systems A n a l y s i s 154 4. Steps i n Computer M o d e l i n g 164 5. E n v i r o n m e n t a l Data f o r the Study Area 181 6. P o p u l a t i o n of the Market Area 182 7. M o r p h o l o g i c a l Chart of System Components 194 8. Water Source E v a l u a t i o n 197 9. Water Conveyance E v a l u a t i o n 199 10. Per Cent Water Use E v a l u a t i o n 201 11. B i o l o g i c a l F i l t e r D esign 202 12. Water Reuse E v a l u a t i o n 203 13. S o l a r H e a t i n g Design and C o s t i n g 205 14. C o n v e n t i o n a l H e a t i n g Design and C o s t i n g 209 15. A e r a t i o n D e s ign Requirements 211 16. Water Treatment E v a l u a t i o n 212 17. F i s h Type E v a l u a t i o n 214 18. F i s h E n c l o s u r e E v a l u a t i o n 215 19. S i z e and Cost of M u l t i t r o p h i c C u l t u r e O p t i o n 217 20. F i s h Food Type E v a l u a t i o n 218 21. Energy Source E v a l u a t i o n 221 22. Energy and Labour Use E v a l u a t i o n 223 23. System Components S e l e c t e d 225 24. Flow Demand C a l c u l a t i o n s ...230 XV 25. P i p e l i n e Design and C o s t i n g 233 26. C a p i t a l Cost C a l c u l a t i o n s 234 27. P r o j e c t e d Income Statement 238 28. Daphnia Model C o e f f i c i e n t s 264 29. A l g a l Model C o e f f i c i e n t s 271 B1. N a t u r a l Food P r o d u c t i o n M o r p h o l o g i c a l Chart 338 B2. N u t r i e n t Type 340 B3. P r i m a r y Producer 341 B4. P r i m a r y Producer V e s s e l 343 B5. P r i m a r y Producer H a r v e s t 344 B6. Secondary Producer 345 B7. Secondary Producer V e s s e l And H a r v e s t 347 B8. M u l t i - T r o p h i c System 349 xvi LIST OF FORMULAE 1 . W i l l o u g h b y L o a d i n g Rate 66 2. E l l i o t L o a d i n g Rate 67 3. L i a o L o a d i n g Rate 68 4. McLean Loading Rate 68 5. P i p e r D e n s i t y L o a d i n g 69 6. Westers D e n s i t y L o a d i n g 69 7. B u t t e r b a u g h and W i l l o u g h b y Feed Rate 70 8. S t a u f f e r Maintenance R a t i o n 71 9. S t a u f f e r Maximum R a t i o n 71 10. McLean Feed Rate 71 11. H a s k e l l Feed Rate 109 12. Hirayama P o l l u t i o n E q u i l i b r i u m 109 13. Gas Mass T r a n s f e r E q u a t i o n 110 14. McLean and Boreham A e r a t i o n Model 112 15. Gross P o p u l a t i o n Summation 121 16. E x p o n e n t i a l Growth 122 17. I n s t a n t a n e o u s Growth 124 18. Monod E q u a t i o n 124 19. M i c h a e l i s - M e n t o n Enzyme K i n e t i c s 125 20. M i c h a e l i s Menton L i m i t i n g F a c t o r 125 21. K u b i t s c h e k L i m i t i n g Chemostat 125 22. H a l f S a t u r a t i o n Constant S o l u t i o n 126 23. MacKenzie L i g h t L i m i t a t i o n M o d i f i e r 134 24. N u t r i e n t L i m i t a t i o n F a c t o r 134 25. Temperature L i m i t a t i o n M o d i f i e r 136 26. C a r r y i n g C a p a c i t y M o d i f i e r 136 xv i i 27. Dugdale G r a z i n g Rate 139 28. Chen and O r l o b Zooplankton Growth 139 29. S t a u f f e r F i s h Growth 143 30. Papst Temperature P o l y n o m i a l 144 31. Iwana and Tautz F i s h Model 145 32. Chen and O r l o b F i s h Growth 145 33. BASIC F i s h Growth 250 34. BASIC Flow Requirements 252 35. BASIC S u r v i v a l Rate 254 36. BASIC Daphnia Growth 260 37. BASIC A l g a e Growth 267 x v i i i ACKNOWLEDGEMENTS Sc i e n c e i s i n e v i t a b l y based on the a c c u m u l a t i o n of knowledge and t e c h n i q u e s by innumerable p e o p l e over unending t i m e . To a l l those s c i e n t i s t s on whose work t h i s paper has drawn, i n c l u d i n g those not s p e c i f i c a l l y r e f e r e n c e d i n the t e x t , my s i n c e r e s t and humblest thankyou. Dr. John W. Zahradnik p r o v i d e d the i n s p i r a t i o n f o r t h i s work and over the y e a r s has been v e r y s u p p o r t i v e ( m o r a l l y and f i n a n c i a l l y ) and p a t i e n t . I am v e r y g r a t e f u l t o him f o r l e t t i n g me be h i s s t u d e n t . I thank the o t h e r committee members, Dr. Norman J . W i l i m o v s k y and P r o f e s s o r Len M. S t a l e y , f o r t h e i r f o r e b e a r a n c e both i n w a i t i n g f o r the t h e s i s t o appear and i n r e a d i n g t h r o u g h i t . Thanks s h o u l d a l s o be extended t o the Guichon f a m i l y of Q u i l c h e n a , B. C , whose ranch i s the s u b j e c t of the a n a l y s i s . The s t a f f and f a c u l t y of s e v e r a l U. B. C. Departments have been very h e l p f u l e i t h e r d i r e c t l y on v a r i o u s problems or i n d i r e c t l y by p r o v i d i n g the means by which problems c o u l d be t a c k l e d . Thanks t o B i l l Webb, Warren K l e i n , Dr. Ray H i l b o r n and Dr. C a r l W a l t e r s of the I n s t i t u t e of Animal Resource E c o l o g y f o r SIMCON and FMT; Dave T a i t of the F a c u l t y of F o r e s t r y f o r the e x c e l l e n t g r a p h i c s package f o r SIMCON; Dr. B i l l N e i l f o r a d v i c e on z o o p l a n k t o n c u l t u r e ; K e i t h McPherson of B. C. R e s e a r c h f o r i n t r o d u c i n g me t o p l a n t l a y o u t , and Dr. F r e i d a Taub of the U n i v e r s i t y of Washington f o r h e l p and a d v i c e on a l g a l c u l t u r e s . My f r i e n d s and c o l l e a g u e s a t the Department of F i s h e r i e s x i x and Oceans have been a g r e a t h e l p t o me over the y e a r s : Bruce Shepherd and Dr. K e i t h Sandercock have a l l o w e d me some time t o complete t h i s work; my computer modeling draws h e a v i l y on the p r e v i o u s work, t u t e l a g e and example of B i l l McLean, Cam West, Dave H a r d i n g and Anne K l i n g ; the s t a f f s of SEP E n g i n e e r i n g and F a c i l i t y O p e r a t i o n s a r e much a p p r e c i a t e d f o r the q u a l i t y of t h e i r work and t h e i r a s s i s t a n c e i n l e a r n i n g about salmon h a t c h e r i e s and t h e i r d e s i g n . Thanks a l s o t o Hugh Sparrow, Dr. A r t Tautz and L e i f Sunde of the B. C. F i s h and W i l d l i f e Branch f o r i n f o r m a t i o n on t h e i r and o t h e r t r o u t r e a r i n g a c t i v i t i e s . S p e c i a l thanks go t o the f a c u l t y , s t u d e n t s and s t a f f of the Department of B i o - R e s o u r c e E n g i n e e r i n g and A g r i c u l t u r a l Mechanics f o r the o p p o r t u n i t y t o work among them d u r i n g my s t a y at U. B. C : N e i l J a c k s o n , J u r g e n P e l k e , Pat Hanna, E n i d S t e w a r t , Mike and Margaret M i k o , Dr. P i n g L i a o , Dr. Ben A b d u l l a h , Dr. S i e t a n C h i e n g , B a r r y Thate, Ara B a l a b a n i a n , Dave Shepherd, Andy Chan, Dr. Ross B u l l e y and the s t a f f of the O y s t e r R i v e r Research Farm. E x t r a s p e c i a l thanks t o Raul P i e d r a h i t a , now of U. C. D a v i s , f o r h i s t i m e l y a s s i s t a n c e i n m u l t i - t r o p h i c m o d e l i n g . My a q u a c u l t u r e e d u c a t i o n has been augmented by p e o p l e i n f i s h farms and r e s e a r c h i n s t i t u t i o n s a l l around the w o r l d and I would l i k e t o extend my a p p r e c i a t i o n t o them f o r the time spent w i t h me: Hans Lehman and f a m i l y of M i s s i o n ; K a r l V i e r k e of S u r r e y , B. C ; Gene Henderson of S t . Andrews, N. B.; Dr. Pete Mulder i n South A f r i c a ; Dr. M a r t i n B o h l i n B a v a r i a ; Dr. Bob Morgan i n S c o t l a n d ; Dr. J . Bwazondi i n T a n z a n i a ; Mr. Chan i n XX S i n g a p o r e ; Dr. C r a i g P a u l s e n i n Hawaia(now S e a t t l e ) ; and innumerable f i s h h a t c h e r y managers and s t a f f i n A u s t r a l i a , New Z e a l a n d , C a l i f o r n i a , Oregon, Washington, Idaho, Montana, Hong Kong, M a l a y s i a , T h a i l a n d , S w i t z e r l a n d , and a t both F e d e r a l and P r o v i n c i a l f a c i l i t i e s on both c o a s t s of Canada. I would l i k e t o thank my f a m i l y and f r i e n d s f o r y e a r s of t o l e r a n c e i n p u t t i n g up w i t h promises to f i n i s h t h i s work. F i n a l l y and most i m p o r t a n t l y I wish t o thank my dear w i f e Cammi, f o r c o n s i d e r a b l e f i n a n c i a l s u p p o r t , immeasurable moral support and i n v a l u a b l e h e l p i n t y p i n g and p r o o f r e a d i n g most of the t e x t . To her t h i s t h e s i s i s l o v i n g l y d e d i c a t e d . 1 I . BACKGROUND 2 j _ . INTRODUCTION A. J u s t i f i c a t i o n The e a r t h ' s n a t u r a l r e s o u r c e s and the c o n t i n u a t i o n of our p r e s e n t c i v i l i z a t i o n a r e s e v e r e l y l i m i t e d . Meadows et a l . (1972) showed, by e x t r a p o l a t i n g p r e s e n t consumption and growth r a t e s compared t o r e s o u r c e r e s e r v e s and p r o d u c t i o n r a t e s , t h a t most r e s o u r c e s w i l l r each a c r i t i c a l l i m i t i n g c a p a c i t y by the e a r l y 21st c e n t u r y f o l l o w e d by a c o l l a p s e of the w o r l d i n d u s t r i a l and food systems ( F i g u r e 1.). T h i s i s because man's economic s t r u g g l e i n the l a s t m i l l e n i a has c e n t r e d on low e n t r o p y energy forms which Georgescu-Roegen (1973) c a l l s 'Stock' forms, the most i m p o r t a n t of which a r e f o s s i l f u e l s ( o i l , c o a l , n a t u r a l g a s ) . Dependence on 'Stock' energy has a b u i l t - i n o b s o l e s c e n c e , because a l l low e n t r o p y m a t e r i a l s e v e n t u a l l y degrade. A l t h o u g h 'Stock' forms are l i m i t e d i n t h e i r t o t a l energy v a l u e , t h e i r consumption r a t e i s u n l i m i t e d , making them v e r y p o p u l a r but l e a d i n g t o t h e i r r a p i d d e p l e t i o n . Georgescu-Roegen s u g g e s t s t h a t we must r e d i r e c t our r e s o u r c e t h i n k i n g t o the use of the o t h e r major energy form--'Flow' energy. T h i s i s d e r i v e d from c e l e s t i a l s o u r c e s (sun, moon, g r a v i t y ) and i s c o n v e r t e d i n t o the n a t u r a l phenomena of l i g h t , h e a t , wind, f l o w i n g water, t i d e s and b i o l o g i c a l p r o d u c t i o n . The consumption r a t e of 'Flow' energy forms i s l i m i t e d by the c e l e s t i a l i n p u t s but the s u p p l y i s c o n t i n u o u s and thus the t o t a l amount of energy i s u n l i m i t e d . WORLD MODEL STANDARD RUN (ha "standard" world modal run assumes no major change In the physical, economic, or social relationships that have historically governed the development of the world system. All variables plotted here follow hhlorical value* from 1900 lo 1970. food, industrial output, and population grow exponentially until th* rapidly diminishing resource base forces a slowdown In induslrial growth. Because of natural delays in the system, both population and pollution continue to increato lor tome time after the peak ol industrialization. Population growth is finally halted by a rise in fho death rate due lo decreased food and medical service*.' STABILIZED WORLD MODEL I technological policies are added to the growth-regulating pol-icies of the previous run lo produce aa equilibrium ttaie sustain-able far Into the future, technological policies Include resource recycling, pollution control devices, increased lifetime of a l l form* of capital, and method* to restore eroded and Infertile soil. Value changes Include inc.edsed emphasis on food and services rather than on industrial production. Births are set equal lo deaths and industrial capital investment equal lo capital depreciation. Equilibrium value of Industrial output per capita is three limes the 1970 world average. Figure 1. The state of World A f f a i r s (from Meadows et a l . , 1972) 4 B u c k m i n s t e r F u l l e r (1968) s u g g e s t s t h a t the most i m p o r t a n t c r i t e r i o n i n the c o n t i n u a n c e of c i v i l i z a t i o n i s the t o t a l w e a l t h of the c u l t u r e . Wealth i s d e f i n e d i n t h i s case a s : "our o r g a n i z e d a b i l i t y t o cope e f f e c t i v e l y w i t h the environment i n s u s t a i n i n g our h e a l t h y r e g e n e r a t i o n and d e c r e a s i n g both the p h y s i c a l and m e t a p h y s i c a l r e s t r i c t i o n s of the f o r w a r d days of our l i v e s . " F u l l e r argues t h a t s i n c e : 1) the ongoing i n p u t of p h y s i c a l e n e r g y ( F l o w energy) i s c o n s t a n t and; 2) s i n c e the m e t a p h y s i c a l r e s t r i c t i o n s can o n l y d e c r e a s e as the knowledge t h a t d e a l s w i t h them i n c r e a s e s ; then w e a l t h must o n l y i n c r e a s e . T h i s e x p l a i n s why h a l f of humanity p r e s e n t l y s u r v i v e s a t a l e v e l of co m f o r t undreamed of a c e n t u r y ago, when l e s s than one p e r c e n t had any s t a n d a r d of l i v i n g a t a l l . The m e t a p h y s i c a l know-how t h a t we a p p l y t o our energy quota d e t e r m i n e s the amount of use we can get out of any p a r t i c u l a r r e s o u r c e . Every r e s o u r c e i s e v e n t u a l l y consumed i n some way or another but o f t e n non-consumptive uses may be made of i t b e f o r e i t reaches i t s consumptive end. Water i s a p a r t i c u l a r l y good example of a m u l t i p l e use r e s o u r c e which can be put t o many non-consumptive uses (such as n a v i g a t i o n , t r a n s p o r t , r e c r e a t i o n , h y d r o - e l e c t r i c g e n e r a t i o n , f i s h p r o d u c t i o n ) b e f o r e b e i n g used up by p l a n t r e s p i r a t i o n , a n i m a l r e s p i r a t i o n , e v a p o r a t i o n or m a i n t a i n i n g ocean l e v e l s . The p h y s i c a l energy e x t r a c t e d from a u n i t of f r e s h f l o w i n g water i s r e s t r i c t e d , but the p o t e n t i a l w e a l t h of such a u n i t may be u n l i m i t e d . M u l t i p l e use of Flow energy r e s o u r c e s i s d e s i r a b l e to get maximum b e n e f i t . B i o l o g i c a l p r o d u c t i o n i n the a q u a t i c 5 environment i s u s u a l l y g r e a t e r per u n i t i n p u t than t h a t on l a n d (Vacek, 1973), because of the m e c h a n i c a l s u p p o r t g i v e n the organisms by the water. These arguments g i v e at l e a s t h i g h l e v e l j u s t i f i c a t i o n f o r i n v e s t i g a t i n g the p o t e n t i a l f o r a q u a c u l t u r a l development. The c h r o n i c s t a t u s of the w o r l d food p r o d u c t i o n and the imminent l i m i t a t i o n s of a g r i c u l t u r e t o meet p a r t i c u l a r l y the p r o t e i n needs of the w o r l d ' s expanding p o p u l a t i o n (Meadows e t a l . , 1972) g i v e s a much more g r a s s r o o t s j u s t i f i c a t i o n f o r the i n v e s t i g a t i o n s of any p o s s i b i l i t i e s of i n c r e a s i n g the p r o t e i n biomass p r o d u c t i o n from any g i v e n s i t e . P a r t i c u l a r l y amenable t o a q u a c u l t u r a l development a r e a r e a s where a g r i c u l t u r e i s a l r e a d y w e l l d e v e l o p e d and where the a l r e a d y e x i s t i n g systems w i l l s upport the development phases of the new system. Combining an a q u a c u l t u r a l development w i t h an a g r i c u l t u r a l system would be m u t u a l l y b e n e f i c i a l i n the c o s t s h a r i n g of machinery, equipment, l a b o u r , t r a n s p o r t and s t o r a g e . A g r i c u l t u r e farms are g e n e r a l l y c h a r a c t e r i z e d as h a v i n g l o t s of l a n d w i t h l i m i t e d amounts of water, whereas a q u a c u l t u r e farms need l i t t l e l a n d and though they w i l l u t i l i z e a l l the water they can g e t , they o n l y use i t as a medium of growth and do not consume i t . J u s t as i m p o r t a n t as the c o s t s h a r i n g b e n e f i t s a r e the management b e n e f i t s which come from the r a i s i n g of a n i m a l s i n c a p t i v e e n v i r o n m e n t s . A l o n g w i t h the economic a s s i s t a n c e s o f f e r e d t o f a r m e r s , the farmer's e x p e r t i s e i n a n i m a l husbandry and h i s r e q u i r e d t w e n t y - f o u r hour day, seven day week c a r e and a t t e n t i o n l i f e s t y l e would be i n v a l u a b l e . B r i t i s h Columbia has a c o n s i d e r a b l e p o t e n t i a l as an 6 a q u a t i c a l l y p r o d u c t i v e a r e a , proven y e a r l y by the tremendous s p o r t f i s h e r y enjoyed throughout the p r o v i n c e (Pearce Bowden, 1971). I t i s o f t e n argued t h a t the development of an a q u a c u l t u r e i n d u s t r y i n B.C. would a d v e r s e l y a f f e c t the e x i s t i n g w i l d caught commercial f i s h e r y i n the marine environment and the a n g l i n g i n d u s t r y i n the f r e s h w a t e r environment. However, i t may e q u a l l y be argued t h a t the i n c r e a s e d a v a i l a b i l i t y of f i s h p r o d u c t s (most of which are p r e s e n t l y imported) on the market p l a c e may i n c r e a s e the per c a p i t a consumption of f i s h i n B. C. and thus i n c r e a s e the v a l u e of the o t h e r two i n d u s t r i e s . In the i n v e s t i g a t i o n of the f e a s i b i l i t y of p r o p o s i n g a q u a c u l t u r a l development f o r B. C , the f i r s t s t e p must be an a n a l y t i c a l one, which b r i n g s t o g e t h e r a v a i l a b l e i n f o r m a t i o n on the s u b j e c t — c o n s t r a i n t s , d e s i g n c r i t e r i a , c u l t u r e c o n d i t i o n s and a l t e r n a t i v e s — a n d e s s e n t i a l l y t r i e s t o e i t h e r d i s c o v e r some reason why f u r t h e r i n v e s t i g a t i o n would be h o p e l e s s , or t o d e v e l o p p r i o r i t i e s t o g u i d e r e s e a r c h . T h i s systems a n a l y s i s approach i s much l e s s c o s t l y than p i l o t p l a n t s , s c a l e models or p r o t o t y p e s t u d i e s and s h o u l d precede these t o d etermine which c r i t i c a l f a c t o r s need t o be r e s e a r c h e d f u r t h e r b e f o r e commitments a r e made. Buc k m i n s t e r F u l l e r (1981) p u t s i t t h i s way: "In s c i e n t i f i c p r o g n o s t i c a t i o n we have a c o n d i t i o n analagous t o a f a c t of a r c h e r y - the f a r t h e r back you are a b l e t o draw your l o n g bow, the f a r t h e r ahead you can s h oot." 7 B. Problem F o r m u l a t i o n a. I n t r o d u c t i o n The problem i n v e s t i g a t e d i n t h i s paper i s the v i a b i l i t y of a q u a c u l t u r a l p r o d u c t i o n on an e x i s t i n g a l f a l f a and c a t t l e ranch i n the N i c o l a v a l l e y of B. C. The s i t e was chosen somewhat a r b i t r a r i l y , m a i n l y because of the e x i s t e n c e of an o p e r a t i n g s u r f a c e i r r i g a t i o n system which c o u l d be c o n n e c t e d t o the t a i l w aters of any a q u a c u l t u r a l f a c i l i t y and t h e r e b y s i m u l t a n e o u s l y abate n u t r i e n t l o a d i n g p o l l u t i o n from the l a t t e r w h i l e p r o v i d i n g n u t r i e n t e n r i c h e d i r r i g a t i o n water f o r the former. I f an a q u a c u l t u r e p r o j e c t can be proven t o be f e a s i b l e f o r a 'worst' case l o c a t i o n such as t h i s w i t h a r a t h e r severe c l i m a t e and r e s t r i c t e d s u p p l y of water, 'then c o n c l u s i o n s s h o u l d be more t r a n s f e r a b l e t o a r e a s w i t h s l i g h t e r r e s t r i c t i o n s than i f a 'best' case s i t e were chosen f o r the s t u d y . I n s t e a d of p i c k i n g a c e r t a i n k i n d of a q u a c u l t u r e o p e r a t i o n and t e s t i n g whether or not i t c o u l d c o n c e i v a b l y be c a r r i e d out on the chosen s i t e , an attempt has been made t o d e s i g n a f a c i l i t y p a r t i c u l a r l y s u i t e d t o the s i t e by e v a l u a t i n g a range of a l t e r n a t i v e s t o d etermine which b e s t s a t i s f i e s the c o n d i t i o n s of p r o d u c t i o n w i t h i n the r e s t r a i n t s c h a r a c t e r i s t i c of the l o c a t i o n . I t i s i m p o r t a n t t o note t h a t the emphasis i s on d e s i g n i n g a system t h a t w i l l be f e a s i b l e as opposed t o e v a l u a t i n g p r e c o n c e i v e d d e s i g n s . T h i s , b a s i c a l l y , i s the d i f f e r e n c e between the e n g i n e e r i n g ( a p p l i e d s c i e n c e ) 'make-it-work' and the pure s c i e n c e ' t e s t - i f - i t - w o r k s ' o u t l o o k s . 8 b . H y p o t h e s i s S t a t e m e n t The h y p o t h e s i s o f t h i s t h e s i s i s t h a t some k i n d o f f r e s h w a t e r a q u a c u l t u r e a t a p a r t i c u l a r l o c a t i o n i n t h e B . C . i n t e r i o r w o u l d be e c o n o m i c a l l y f e a s i b l e . The h y p o t h e s i s i s t e s t e d by d e s i g n i n g , e v a l u a t i n g a n d s i m u l a t i n g a f a c i l i t y w h i c h w o u l d h a v e t h e b e s t p r o b a b i l i t y o f e c o n o m i c v i a b i l i t y . The d e s i g n a n d e v a l u a t i o n a r e l i m i t e d t o t h e c o n c e p t u a l s t a g e , w h e r e t h e l e v e l o f d e t a i l i s r e s t r i c t e d t o t h o s e m a j o r q u e s t i o n s m o s t r e l e v a n t t o d e t e r m i n i n g f e a s i b i l i t y . D e t a i l e d d e s i g n , c o n s t r u c t i o n a n d p i l o t t e s t i n g a r e l e f t t o a f u t u r e s t u d y . T h e r e a r e t w o b a s i c t h e m e s c o v e r e d i n t h e p a p e r : f i r s t l y t h a t a q u a c u l t u r e i s p o s s i b l e a n d s e c o n d l y t h a t s i m u l a t i o n m o d e l l i n g o f t h e c u l t u r e s y s t e m i s p o s s i b l e . E a c h o f t h e s e t h e m e s i s b a s e d on i n f e r e n c e s d r a w n f r o m p r o p o s i t i o n s known t o be t r u e a n d p r o p o s i t i o n s a s s u m e d t o be t r u e f o r t h e s a k e o f t h i s s t u d y . THEME J_ A q u a c u l t u r e i s P o s s i b l e i n t h e B . C . I n t e r i o r P r o p o s i t i o n s Known t o be T r u e 1. Many s p e c i e s o f f i s h h a v e b e e n c u l t u r e d u n d e r a w i d e v a r i e t y o f c o n d i t i o n s w o r l d w i d e . 2 . The B . C . i n t e r i o r c l i m a t e i s s u i t a b l e f o r f i s h p r o d u c t i o n . 3 . Some f i s h c u l t u r e h a s b e e n s u c c e s s f u l u n d e r c o n d i t i o n s w h i c h a t l e a s t p a r t i a l l y m a t c h t h o s e o f t h e B . C . i n t e r i o r . 9 4 . C u l t u r e d f i s h a r e s u c c e s s f u l l y marketed a t p r e s e n t i n B. C. P r o p o s i t i o n s Assumed t o be True 1 . F i s h p r o d u c t i o n t e c h n o l o g i e s can be s e l e c t i v e l y t r a n s f e r r e d t o new c o n d i t i o n s . 2 . There i s ample room f o r c u l t u r e d f i s h market growth i n B. C. I n f e r e n c e s 1 . F i s h c u l t u r e i n B. C. i s b i o l o g i c a l l y f e a s i b l e . 2 . F i s h c u l t u r e i n B. C. i s t e c h n i c a l l y f e a s i b l e . 3 . F i s h c u l t u r e i n B. C. i s e c o n o m i c a l l y f e a s i b l e . THEME 2 AQUATIC PRODUCTION CAN BE MODELLED AND SIMULATED P r o p o s i t i o n s Known t o be True 1 . A q u a t i c p r o d u c t i o n i s r e l a t e d t o e n v i r o n m e n t a l p a r a m e t e r s . 2 . Mass i s c o n s e r v e d i n b i o l o g i c a l t r a n s f o r m a t i o n s . P r o p o s i t i o n s Assumed t o be True 1. C e r t a i n e s t a b l i s h e d m a t h e m a t i c a l f o r m u l a t i o n s can approximate b i o l o g i c a l and p h y s i c a l t r a n s f o r m a t i o n s , p r o d u c t i o n and consumption r a t e s . 2 . C r i t i c a l e n v i r o n m e n t a l d r i v i n g v a r i a b l e s can be d e r i v e d from a v a i l a b l e i n f o r m a t i o n . I n f e r e n c e s 1. A q u a t i c p r o d u c t i o n can be m o d e l l e d w i t h r e s p e c t t o e n v i r o n m e n t a l c o n d i t i o n f o r a g i v e n s i t e . 1 0 c . A n a l y s i s O b j e c t i v e s The t h e o r e t i c a l i n f e r e n c e s l e a d t o t h e r e s e a r c h o b j e c t i v e s t o be s t r i v e d f o r i n t h i s t h e s i s . The o b j e c t i v e s o f t h e s y s t e m a n a l y s i s p a r t a r e t o : 1 . D e s i g n a n a q u a c u l t u r e s y s t e m t o be c o u p l e d t o a n a l r e a d y e x i s t i n g a g r i c u l t u r e s y s t e m . 2 . D e t e r m i n e t h e v a r i o u s f e a s i b i l i t i e s o f t h e s y s t e m d e s i g n e d — t e c h n i c a l , b i o l o g i c a l a n d e c o n o m i c . 3 . G e n e r a t e a n d e v a l u a t e a r a n g e o f a l t e r n a t i v e d e s i g n s w h i c h c o u l d be u s e d t o c o n s t r u c t s u c h a s y s t e m . 4 . D e t e r m i n e t h e a r e a s o f g r e a t e s t u n c e r t a i n t i e s w i t h i n t h e d e s i g n s . 5 . S e t down r e s e a r c h p r i o r i t i e s i n t h e a r e a s o f i m p o r t a n c e c r i t i c a l t o t h e p o t e n t i a l e c o n o m i c v i a b i l i t y . The o b j e c t i v e s o f t h e m o d e l i n g p a r t o f t h i s t h e s i s a r e : 1. To c o n s t r u c t m a t h e m a t i c a l c o m p u t e r m o d e l s o f a s p e c t s o f a q u a t i c p r o d u c t i o n u s i n g r e l a t i o n s h i p s g l e a n e d f r o m t h e l i t e r a t u r e . 2 . To u s e t h e s e m o d e l s i n t h e e v a l u a t i o n a n d d e s i g n p r o c e s s e s o f t h e a l t e r n a t i v e d e s i g n s . 11 C. T h e s i s O u t l i n e The remainder of t h i s paper i s o r g a n i z e d i n t o the s t a n d a r d s c i e n t i f i c form of R e l a t e d R e s e a r c h , Methodology, R e s u l t s and C o n c l u s i o n s . With r e s p e c t t o the systems a n a l y s i s approach t o the problem, th e s e headings have taken on meanings which a r e unique t o t h i s k i n d of s t u d y . The R e l a t e d R e s e a r c h s e c t i o n a c t u a l l y i n c l u d e s a r a t h e r l a r g e r compendium of i n f o r m a t i o n on the v a r i o u s t o p i c s than i s t r a d i t i o n a l l y found. T h i s i s d i r e c t l y r e l a t e d t o the c a p a c i t y of the systems a n a l y s i s t o handle a wide range of d e s i g n a l t e r n a t i v e s i n o r d e r t o come up w i t h h i g h l y c r e d i b l e s o l u t i o n o p t i o n s . Much of t h i s i n f o r m a t i o n may r i g h t l y b e l o n g i n the d i s c u s s i o n of a l t e r n a t i v e s (which would make t h a t s e c t i o n too l a r g e and u n w i e l d y ) or i n the ap p e n d i c e s (except t h a t i t i s too s u b j e c t i v e ) , but the R e l a t e d R e s e a r c h has been m o d i f i e d t o mean ' r e l e v a n t i n f o r m a t i o n c o n t a i n e d i n source l i t e r a t u r e and i t s d i s c u s s i o n . ' r e l a t e d r e s e a r c h on A q u a c u l t u r e i s s e p a r a t e d i n t o two s e c t i o n s : A q u a c u l t u r a l O p e r a t i o n s d i s c u s s e s the g e n e r a l p r o c e s s e s i n v o l v e d i n the r e a r i n g of a q u a t i c a n i m a l s , and A q u a c u l t u r a l Design d i s c u s s e s the parameters which must be c o n s i d e r e d i n the d e s i g n of a f a c i l i t y , a l o n g w i t h the a l t e r n a t i v e d e s i g n c o n f i g u r a t i o n s which may be used i n the system. The Methodology s e c t i o n d i s c u s s e s the methods used i n the systems a n a l y s i s and the m o d e l l i n g and g i v e s an o u t l i n e of the p r o c e d u r e s used i n t h i s a n a l y s i s . The R e s u l t s s e c t i o n i n c l u d e s a complete run through of the 12 systems a n a l y s i s and m o d e l l i n g p r o c e d u r e s w i t h r e f e r e n c e t o the t o p i c s of B. C. t r o u t f a r m i n g f e a s i b i l i t y and computer models of a q u a t i c p r o d u c t i o n . Thus the R e s u l t s s e c t i o n c o n t a i n s much more than j u s t the r e s u l t s of the systems a n a l y s i s and system m o d e l - - i t r e a l l y c o n t a i n s the r e s u l t s of the M a s t e r s T h e s i s work. C o n c l u s i o n s c o n t a i n s a d i s c u s s i o n of the r e s u l t s and c o n c l u s i o n s drawn from them, the a n a l y s i s ' l i m i t a t i o n s and f u t u r e r e s e a r c h needs. RELATED RESEARCH 1 4 2. AQUACULTURAL OPERATIONS A. G e n e r a l a. Purpose A q u a c u l t u r e i s d e f i n e d as the growing of a q u a t i c organisms under c o n d i t i o n s of v a r i e d c o n t r o l . The d e f i n i t i o n i s not l i m i t e d t o f i s h c u l t u r e and may i n c l u d e the f a r m i n g of a l l a q u a t i c p l a n t s and a n i m a l s , a l t h o u g h i t n o r m a l l y r e f e r s o n l y t o the c u l t u r e of a l g a e , s h e l l f i s h and f i s h i n marine, b r a c k i s h and f r e s h water e n v i r o n m e n t s . The o b j e c t i v e of a q u a c u l t u r e , l i k e i t s t e r r e s t r i a l c o u n t e r - p a r t a g r i c u l t u r e , i s t o c i r c u m v e n t the f a c t o r s t h a t l i m i t n a t u r a l p o p u l a t i o n s (Royce, 1972) o r , as H i c k l i n g (1972) p u t s i t , " t o i n c r e a s e by a l l p o s s i b l e means the p r o d u c t i o n of food f a r above the l e v e l which would be produced n a t u r a l l y . " These 'means' i n c l u d e the s c i e n c e and a r t of managing the growth and h e a l t h of the organisms by p r o v i d i n g a s u i t a b l e water environment, n u t r i t i o n and f e e d i n g , b r e e d i n g and s e l e c t i o n , d i s e a s e c o n t r o l and s t o c k i n g d e n s i t y (Reay, 1979). A q u a c u l t u r e may be c a r r i e d out f o r many p u r p o s e s , the most common of which i s the p r o v i s i o n of food f o r human consumption. I n d u s t r i a l a q u a c u l t u r e i n c l u d e s seaweed c u l t u r e f o r p h y c o c o l l o i d e x t r a c t i o n (Chapman, 1970), o y s t e r c u l t u r e f o r p e a r l s (Furukawa, 1971), and v a r i o u s f i s h and s h e l l f i s h c u l t u r e s f o r t o t a l or p a r t i a l r e d u c t i o n t o f i s h o i l , f i s h meal, and f e r t i l i z e r ( F i r t h , 1969) as w e l l as f o r e x t r a c t i o n of 15 p h a r m a c o l o g i c a l l y i m p o r t a n t c h e m i c a l s (Beslow, 1969). Both p l a n t s and a n i m a l s have been c u l t u r e d i n schemes i n v o l v i n g the r e c y c l i n g of waste waters (Dunstan and Tenore, 1972; R y t h e r et a l . , 1972). Ornamental f i s h e s , many of which a r e c u l t u r e d , have a t o t a l w o r l d a n n u a l r e t a i l v a l u e of a p p r o x i m a t e l y $4 b i l l i o n , i n c l u d i n g a c c e s s o r i e s (Conroy, 1975). A q u a c u l t u r e f o r the s p o r t f i s h i n g i n d u s t r y i s second o n l y t o commercial food f i s h a q u a c u l t u r e i n numbers of f i s h c u l t i v a t e d i n N o r t h A m e r i c a , i n c l u d i n g the b r e e d i n g and r e a r i n g of j u v e n i l e s t o r e j u v e n a t e d e p l e t e d n a t u r a l p o p u l a t i o n s and the i n t e n s i v e pond c u l t u r e of b a i t f i s h ( D a v i s , 1953). Commercial food a q u a c u l t u r e a l s o c o m p r i s e s both a r t i f i c i a l r e c r u i t m e n t t o n a t u r a l p o p u l a t i o n s and the c o m p l e t e l y c o n t r o l l e d growth from b r e e d i n g t o p r o c e s s i n g . For the purpose of t h i s paper, we s h a l l m o s t l y c o n s i d e r o n l y the c u l t u r e of organisms f o r f o o d , w i t h p a r t i c u l a r r e f e r e n c e g i v e n t o f r e s h w a t e r f i s h c u l t u r e , a l t h o u g h some v a l u a b l e l e s s o n s can be l e a r n e d from o t h e r t y p e s of c u l t u r e . b. H i s t o r y The p r a c t i c e of some form of c o n t r o l l e d containment of f i s h d a t e s from b e f o r e 2000 B. C , when, a c c o r d i n g t o H i c k l i n g (1972), b o t h the E g y p t i a n s and the Chinese had d r a i n a b l e f i s h p o n d s which were p r o b a b l y s t o c k e d i n i t i a l l y w i t h w i l d -caught T i l a p i a ( T i l a p i a n i l o t i c a ) and c a r p ( C y p r i n u s c a r p i o ) . A l t h o u g h Huet (1972) shows a p i c t u r e of c i r c u l a r b r e e d i n g ponds i n c e n t r a l I t a l y d a t i n g from Roman t i m e s , m e d i e v a l f i s h c u l t u r e 16 i n the western hemisphere was m o s t l y i n the form of h o l d i n g w i l d - c a u g h t f i s h i n stew ponds so as t o keep them f r e s h f o r the t a b l e . Many of the p r e s e n t , sound pond c u l t u r e p r a c t i c e s were known when the f i r s t E n g l i s h t r e a t i s e s on the s u b j e c t were w r i t t e n i n the e a r l y s e v e n t e e n t h c e n t u r y ( H i c k l i n g , 1972). F i s h c u l t u r e had d i f f e r e n t o r i g i n s the w o r l d around. In T h a i l a n d i t s t a r t e d as an a l t e r n a t e use of s a l t pans, i n I n d i a i t d e veloped d u r i n g a g r i c u l t u r a l l a n d r e c l a m a t i o n p r o j e c t s where d i k e s were b u i l t t o t r a p the s i l t i n r u n o f f water, and i n I n d o n e s i a b r a c k i s h water pond c u l t u r e was p r a c t i s e d by c o n v i c t s who were not a l l o w e d t o c u l t i v a t e l a n d ( P i l l a y , 1973). In N o r t h A m e r i c a , by 1850, the w e l l e s t a b l i s h e d European t e c h n i q u e s of b r e e d i n g , i n c u b a t i n g , h a t c h i n g and r e a r i n g f i s h were used t o t r y t o b o l s t e r the d w i n d l i n g s p o r t f i s h s t o c k s , which had been l o c a l l y d e p l e t e d from o v e r f i s h i n g and by the c o n s t r u c t i o n of dams t o power i n d u s t r y . By 1853 two American d o c t o r s had a c c o m p l i s h e d the f e r t i l i z a t i o n of brook t r o u t eggs, and by 1865 t a b l e t r o u t c o u l d be bought f o r $.75-$1.25 per pound , a t a time when the g o i n g d a i l y wage was $1.00 (Bowen, 1970). The proven ease of h a t c h i n g s a l m o n i d eggs g e n e r a t e d tremendous ent h u s i a s m among the s p o r t f i s h e r m e n of the i n t e r i o r of N o r t h America and among the commercial f i s h e r m e n of the n o r t h P a c i f i c and A t l a n t i c c o a s t s , and a g r e a t number of h a t c h e r i e s were b u i l t f o r t r o u t i n the i n t e r i o r and f o r salmon on the c o a s t s ( L a r k i n , 1974). By the 1930's most of t h i s e n t h u s i a s m had d i e d o f f when n a t u r a l s t o c k s c o n t i n u e d t o d e c l i n e r e g a r d l e s s of how many m i l l i o n s of f i n g e r l i n g s were r e l e a s e d i n t o r i v e r s , l a k e s 1 7 and e s t u a r i e s . S i n c e World War I I a new approach, t h a t of managing the e n t i r e ecosystem r a t h e r than j u s t r e p l a c i n g the spawning and i n c u b a t i o n b o t t l e n e c k , has taken h o l d i n N o r t h A m e r i c a , s e t t i n g o f f a new t r e n d i n h a t c h e r y b u i l d i n g and o t h e r m a n i p u l a t i o n s c u l m i n a t i n g i n r e c e n t 'Salmonid Enhancement' programs (MacDonald, 1978; G l o v e r , 1983). The pond r e a r i n g of c h a n n e l c a t f i s h was recommended by the U. S. Department of A g r i c u l t u r e as a secondary use of s o i l c o n s e r v a t i o n ponds a f t e r 1930 ( S w i n g l e , 1970), but d u r i n g the 1960's c a t f i s h f a r m i n g reached phenomenal p r o p o r t i o n s and proved i t s e l f a v e r y v i a b l e and r a p i d l y growing i n d u s t r y , the t o t a l a r e a under pond co v e r i n c r e a s i n g from 960 ha. i n 1963 t o 16,194 ha. i n 1969. The end of the Second World War saw g r e a t r e c l a m a t i o n and a g r i c u l t u r a l p r o d u c t i o n schemes a l l over the w o r l d , p a r t i c u l a r y i n w a t e r - r i c h Southeast A s i a . These schemes always i n c l u d e d a c o n s i d e r a b l e e x p a n s i o n of the p r e v i o u s s u b s i s t e n c e f i s h and s h e l l f i s h c u l t u r e systems. T h i s tremendous w o r l d wide e x p a n s i o n of a q u a c u l t u r e as an i n d u s t r y both i n the h e c t a r e s under c u l t i v a t i o n and i n the d o l l a r i n v e s t m e n t , from p r o v i s i o n of seed s t o c k and f e e d t o the p r o c e s s i n g and m a r k e t i n g of the e d i b l e p r o d u c t , c o u p l e d w i t h a more p r o g r e s s i v e , m i s s i o n o r i e n t e d a t t i t u d e of r e s e a r c h i n s t i t u t i o n s , l e d t o a g r e a t growth phase i n pond management t e c h n i q u e s from 1955-1965. Even though the g e n e r a l t e c h n i q u e s had been known f o r 100 y e a r s and s e t out q u i t e c l e a r l y i n S c h a e f f e r c l a u s (1935), the b r e a k t h r o u g h was t h a t the 18 a d m i n i s t r a t o r s were g e t t i n g p o s i t i v e feedback from the s c i e n t i s t s and p a s s i n g the i n f o r m a t i o n a l o n g t o the farmers t h e m s e l v e s . A p r o l i f e r a t i o n of good, p r a c t i c a l f i s h c u l t u r e handbooks have become a v a i l a b l e . A s i m i l a r r e v o l u t i o n i n c o l d w a t e r raceway c u l t u r e o c c u r r e d between 1965-1975, when some of the e a r l i e r guessed-at t e c h n i q u e s were r e p l a c e d by r e v o l u t i o n a r y methods and f a c i l i t y d e s i g n s p e c i f i c a t i o n s s u p p o r t e d by hard d a t a . High c a p i t a l i n v e s t m e n t became the vogue f o r t r o u t and salmon c u l t u r e w i t h complex and d e l i c a t e r e c y c l i n g water systems and massive c o n c r e t e f a c i l i t i e s (Meade, 1976; Burrows and Combs, 1968). The t e c h n o l o g i e s of b r e e d i n g , d i s e a s e c o n t r o l , water q u a l i t y c o n t r o l and system c o o r d i n a t i o n have made l e a p s and bounds i n t o a new e r a i n f i s h c u l t u r e ( P i l l a y and D i l l , 1979). Only g e n e t i c m a n i p u l a t i o n seems t o be l a g g i n g behind i n the soon t o be programmed and automated f i s h f a c t o r y s c e n a r i o of the f u t u r e ( N a t i o n a l Academy of S c i e n c e s , 1978). c. Importance The t o t a l volume of a l l w o r l d f i s h e r i e s c a t c h e s i s l a t e l y h o v e r i n g around the s e v e n t y m i l l i o n m e t r i c tons mark. The c o n t r i b u t i o n made by a q u a c u l t u r e o p e r a t i o n s i s e s t i m a t e d t o be between f i v e and t e n m i l l i o n m e t r i c t o n s . That i n c l u d e s about 3.5 m i l l i o n from known s o u r c e s and an i n d e t e r m i n a t e 1.5-6.5 from m a i n l a n d C h i n a . E s t i m a t e s of the p o t e n t i a l p r o d u c t i o n from a q u a c u l t u r e , as t h o s e of the p o t e n t i a l w i l d - c a u g h t c o n t r i b u t i o n , v a r y 19 t r e m e n d o u s l y . Based on known o p t i m a l development of p r e s e n t l y u t i l i z e d w i l d r e s o u r c e s , the w o r l d f i s h e r y p o t e n t i a l i s around 100 m i l l i o n m e t r i c t o n s , but use of r e s o u r c e s not now p r e s e n t l y used c o u l d r a i s e t h a t t o 300 MMT. Based on e s t i m a t e s of t o t a l p r i m a r y p r o d u c t i o n (Rhodin et a l . , 1972), p o t e n t i a l t e r t i a r y p r o d u c t i o n c o u l d be 500-700 MMT. A q u a c u l t u r e cannot be e s t i m a t e d on the same grounds, s i n c e i t i n v o l v e s the development of a r e s o u r c e where none e x i s t e d b e f o r e . Based on water and l a n d a v a i l a b i l i t y , a t l e a s t a ten f o l d i n c r e a s e i n p r o d u c t i o n i s e s t i m a t e d t o be p o s s i b l e by the y e a r 2000, making p r o d u c t i o n e q u a l t o the p r e s e n t w i l d - c a u g h t f i s h e r y p r o d u c t i o n (Bardach et a l . , 1972). A q u a c u l t u r e t e c h n o l o g y i s q u i t e d i f f e r e n t between t r o p i c a l / s u b t r o p i c a l a r e a s and temperate a r e a s . T r o p i c a l a q u a c u l t u r e i s dominated by pond c u l t u r e of s t a p l e food f i s h e s p r o v i d i n g p r o t e i n supplements f o r t r a d i t i o n a l c a r b o h y d r a t e d i e t s . Many t r o p i c a l a r e a s a re a t t e m p t i n g the c u l t u r e of l u x u r y f i s h e s , such as p e n a e i d s h r i m p s . A l t h o u g h c o s t of p r o d u c t i o n per k i l o g r a m of p r o d u c t i s c o n s i d e r a b l y h i g h e r , net income per k i l o g r a m i s a l s o much h i g h e r (Brown, 1983). T h i s u n f o r t u n a t e t u r n from u s e a b l e food p r o d u c t i o n t o money p r o d u c t i o n i s c h a r a c t e r i s t i c of a g r i c u l t u r e i n poor t r o p i c a l c o u n t r i e s and a c c o r d i n g t o Lappe and C o l l i n s (1977), g r e a t l y c o n t r i b u t e s t o f u r t h e r p o v e r t y and s o c i a l i n e q u a l i t y . The a q u a c u l t u r e c o m p e t i t o r s i n temperate c l i m a t e s are the food f i s h and the s p o r t - f i s h subgroups. Cost of p r o d u c t i o n makes both of these l u x u r y f i s h - - o n l y the method of h a r v e s t i s i n d i s p u t e . The 20 s p o r t f i s h c o s t s c o n s i d e r a b l y more per k i l o of p r o duct due t o the c o s t of a n g l i n g equipment, accomodation and t r a v e l (Pearce Bowden, 1 97 1 ) . B. P r i n c i p l e s of A q u a c u l t u r e a. Squeeze L i k e t e r r e s t r i a l a g r i c u l t u r e , a q u a c u l t u r e can be c a r r i e d out under a range of i n t e n s i t i e s of human c o n t r o l . The management may i n v o l v e any c o m b i n a t i o n of v a r i a b l e s a t any stage i n the a n i m a l ' s l i f e h i s t o r y . Bardach et a l . (1972) g i v e us a l i s t of v a r y i n g c o n t r o l f o r a q u a c u l t u r e systems: 1. T r a n s p l a n t a t i o n from poor t o b e t t e r growing grounds. 2. H a t c h e r y r e a r i n g of t r a n s p l a n t e d s t o c k . 3. E n c l o s u r e s of organisms i n s u i t a b l e r e a r i n g a r e a . 4. F e r t i l i z a t i o n and/or water c o n t r o l of r e a r i n g e n c l o s u r e . 5. Ponding r e a r e d f i s h t o the e x c l u s i o n of w i l d f i s h . 6. D i r e c t f e e d i n g r e a r e d f i s h of pond r e a r e d s t o c k . The purpose of i n c r e a s i n g management i n t e n s i t y i s t o i n c r e a s e y i e l d s per u n i t of c u l t u r e water. However, i n t e n s i f i e d management i n p u t a l s o c o s t s more. The r e l a t i o n s h i p between c o s t s ( f i x e d and o p e r a t i n g ) and revenue depends on the i n d i v i d u a l s i t e and the a v a i l a b i l i t y and c o s t of l a n d , l a b o u r , t e c h n o l o g y and s u p p l i e s . B l a x t e r (1973) s t a t e s t h a t "what i s 21 r e g a r d e d an i n t e n s i v e system of fa r m i n g by one g e n e r a t i o n becomes the c o n v e n t i o n a l system of the next and may w e l l prove t o be the t r a d i t i o n a l system of the one t h a t f o l l o w s . Such has c e r t a i n l y been the case w i t h a g r i c u l t u r e and i s a l s o p r o v i n g t o be so w i t h the advent of complex water reuse systems i n a q u a c u l t u r e . " A q u a c u l t u r e management i n v o l v e s many a s p e c t s of an a n i m a l ' s b i o l o g y t h a t can be c o n t r o l l e d and enhanced. These c o n t r o l s a re i n response t o b o t t l e n e c k s i n the development of the n a t u r a l p o p u l a t i o n s . As management i n t e n s i t y i n c r e a s e s , so u s u a l l y does the number of a n i m a l s h e l d per u n i t a r e a or volume i n the c u l t u r e c o n t a i n e r s . The more c o n c e n t r a t e d the a n i m a l s a r e , the more e a s i l y they a r e m o n i t o r e d as t o growth and h e a l t h and the e a s i e r i t i s t o f e e d and c a r e f o r them. There a r e l i m i t s t o how much the f i s h can be crowded t o g e t h e r which depend on the s p e c i e s i n v o l v e d , the water q u a l i t y , t e m p e r a t u r e , d i s s o l v e d oxygen, t o x i c w a s t e s , the a n i m a l ' s age and g e n e r a l c o n d i t i o n . Some a n i m a l s cannot be e f f e c t i v e l y crowded a t a l l , such as young p i k e or l o b s t e r s , due t o c a n n i b a l i s t i c t e n d e n c i e s a t c e r t a i n ages. b. Seed And Breed Assurance of a s u f f i c i e n t s u p p l y of seed s t o c k i s the a q u a c u l t u r i s t ' s f i r s t c o n c e r n . O r i g i n a l l y t h i s i n v o l v e d c o l l e c t i o n of j u v e n i l e f i s h from n a t u r a l w a t e r s t o s t o c k the r e a r i n g ponds, a method s t i l l used i n the c u l t u r e of m i l k - f i s h , 22 prawns and o t h e r s p e c i e s m o s t l y i n d e v e l o p i n g t r o p i c a l n a t i o n s (Huet, 1972). Today t h a t p r a c t i c e i s l i m i t e d m o s t l y t o s p e c i e s who have proven t o be p a r t i c u l a r l y d i f f i c u l t t o breed i n c a p t i v i t y . Seed s t o c k i s more commonly s u p p l i e d nowadays by k e e p i n g a p r o p o r t i o n of the r e a r i n g f i s h u n t i l they are s e x u a l l y mature and then i n d u c i n g them t o spawn by p r o v i d i n g the p r o p e r environment (spawning g r a v e l or reed shade mats) and the p r o p e r s t i m u l u s ( l o w e r i n g water l e v e l s , c h a n g i n g the sex r a t i o ) . The p r o p e r s t i m u l u s may a l s o be a manual i n j e c t i o n of p i t u i t a r y hormone t o induce egg and sperm m a t u r a t i o n . Rather than a l l o w i n g n a t u r a l spawning, advanced f i s h c u l t u r i s t s can m a n u a l l y s t r i p the eggs from the female and f e r t i l i z e them w i t h m i l t m i l k e d from the male. T h i s a l l o w s g r e a t e r c o n t r o l over the next s t e p i n the a q u a c u l t u r i s t ' s j o b , egg i n c u b a t i o n . The i n c u b a t i o n stage i n an a n i m a l ' s l i f e h i s t o r y i s one where the h i g h e s t m o r t a l i t i e s o ccur i n n a t u r e , from e n v i r o n m e n t a l s t r e s s , p r e d a t i o n or d i s e a s e . The f i r s t a t t e m p t s a t i n c r e a s i n g y i e l d s of f r y (or l a r v a e ) from eggs were t o c l e a n up and s t a b i l i z e the n a t u r a l i n c u b a t i o n environment and t o keep out p r e d a t o r s . T h i s t e c h n i q u e i s s t i l l used i n t r o p i c a l pond c u l t u r e where s e p a r a t e s m a l l ponds are s e t a s i d e i n c a r p c u l t u r e , w i t h woven mats t o p r o v i d e a p r o t e c t i v e s u r f a c e under which the eggs a t t a c h . Salmon spawning c h a n n e l s , w i t h c o n t r o l l e d f l o w r a t e over s o r t e d g r a v e l , a l s o f o l l o w t h i s t e c h n i q u e . Even when the f i s h a r e s t r i p p e d and a r t i f i c i a l l y f e r t i l i z e d the eggs can be p l a c e d i n a n a t u r a l or s i m u l a t e d n a t u r a l environment ( i . e . i n c u b a t i o n box, P a r k i n s o n and S l a n e y , 23 1975). More o f t e n , s t r i p p e d eggs, a f t e r f e r t i l i z a t i o n and h a r d e n i n g , a r e p l a c e d i n j a r , t r a y or t r o u g h i n c u b a t o r s ( F i g u r e 2 ) , d e s i g n e d t o d e l i v e r w e l l oxygenated water t o a l l eggs. In such i n c u b a t o r s dead or f u n g u s - r i d d e n eggs can e a s i l y be s p o t t e d and removed, r e d u c i n g s p r e a d of i n f e c t i o n . c. Feed A f t e r the f i s h have hatched and absorbed t h e i r y o l k - s a c the f i s h farmer must ensure t h a t they have a s u f f i c i e n t amount of the p r o p e r f o o d , so t h a t they w i l l grow t o market s i z e a t a r a p i d r a t e . D i f f e r e n t f i s h have s l i g h t l y d i f f e r e n t n u t r i t i o n a l r e q u i r e m e n t s (Subcommittee on F i s h N u t r i t i o n , 1973; H i l t o n and S l i n g e r , 1981), depending on t h e i r a b i l i t y t o s y n t h e s i z e t h e i r v a r i o u s body components from t h e i r food. I t i s g e n e r a l l y assumed, a l t h o u g h sometimes f a l l a c i o u s l y , t h a t a n a t u r a l d i e t i s a n u t r i t i o n a l l y b a l a n c e d one, thus one approach t o f e e d i n g f i s h i s t o f e e d them n a t u r a l f o o d s . T h i s can be done by s t o c k i n g them i n p r o d u c t i v e n a t u r a l waters and h a r v e s t i n g them when they a r e market s i z e , or by growing and h a r v e s t i n g the n a t u r a l food and f e e d i n g i t t o the f i s h i n s e p a r a t e e n c l o s u r e s . F e r t i l i z e r i s o f t e n a p p l i e d t o the water t o i n c r e a s e the p r o d u c t i v i t y of the lower t r o p h i c l e v e l s ( C h a k r o f f , 1976). A r t i f i c i a l l y p r e p a r e d feeds ( i . e . Oregon p e l l e t s , Hublou, 1963; or Abernathy p e l l e t s , F o wler and Burrows, 1971), u s u a l l y made from waste m a t e r i a l s from f i s h e r y , a n i m a l and p l a n t food p r o c e s s i n g , p l u s cheap a v a i l a b l e s o u r c e s of v e g e t a b l e p r o t e i n and o i l ( H a s t i n g s and D i c k i e , 1972), a r e f e d t o e i t h e r 300cm Incubation and rearing Irouph for salmonids. Drawing shows cn!y one of the four Incubation trays (after Schapcrc'ans, 1933). Types of hatching jars used for incubating semibuoyant eggs, a, Downing jar with open top is used for incubating eggs that arc slightly heavier than water; b, McDonald jar with closed top lias been largely superseded by the Downing type—it can be converted into an open-top jar by unscrewing the top. - O U T U T P t ? t S Hatching troughs arranged in pairs with supply pipes at wpper and drainage pipes at lower ends. Fine meshed wire screens are installed a slioi; distance from each end. Drawing of Calirorni;!ii incubator (after Schap-erclaus, 1933). Longitudinal sections of hatching troughs, a, section show-inr arrangement o( tiays without bafllc plates; b, section shewing arrangement of baffle plates to foue water tc flow up through trays or baskets. P-0 H (D M < h P-O n w H> P-W tr fD iQ uQ p-O C cr p> rt o ri cn tc c CO ft vo ro 25 supplement n a t u r a l f e e d i n g or t o c o m p l e t e l y r e p l a c e i t i n v e r y i n t e n s i v e c u l t u r e s . A Chinese f i s h c u l t u r e p r a c t i c e s e v e r a l thousand y e a r s o l d and r e c e n t l y i n t r o d u c e d i n t o s e v e r a l A s i a n and A f r i c a n a r e a s i s the concept of p o l y c u l t u r e . T h i s i s the s i m u l t a n e o u s c u l t u r e i n the same pond of more than one s p e c i e s of f i s h - - s p e c i e s which u t i l i z e d i f f e r e n t , e x c l u s i v e , f e e d i n g n i c h e s ( F i g u r e 3 ) . With f e r t i l i z a t i o n such a system r e p r e s e n t s an i n t e n s i f i e d ecosystem, which i s not v e r y a p p l i c a b l e t o v e r y h i g h l y i n t e n s i v e c u l t u r e . O r i e n t a l s u b s i s t a n c e pond farmers have l o n g c o u p l e d t h e i r ponds t o t h e i r waste d i s p o s a l u n i t s , the p i g excrement and v e g e t a b l e waste h e l p i n g t o f e r t i l i z e the a q u a t i c p r o d u c t i o n . Some r e c e n t work has been done on the use of a n i m a l wastes as d i r e c t food f o r f i s h w i t h some e n c o u r a g i n g r e s u l t s f o r p a r t i c u l a r s p e c i e s (Edwards, 1980; Lu and Kev e r n , 1975; Moav et a l . , 1977; Summer f e l t and Y i n , 1974). The s u c c e s s depends both on the n u t r i t i o n a l q u a l i t y of the manure and on the presence t h e r e i n of t o x i c c h e m i c a l s . d. Growth F i s h growth r a t e i s dependent on many f a c t o r s . Each s p e c i e s or rac e has some g e n e t i c a l l y d e t e r m i n e d maximum growth r a t e , g i v e n i d e a l c o n d i t i o n s , and t h i s i s d e c r e a s e d by age and by d e v i a t i o n from the optimum v a l u e s of water t e m p e r a t u r e , ammonium and oxygen c o n c e n t r a t i o n , b a l a n c e d r a t i o n and h e a l t h ( L a g l e r e t a l . , 1977). I f the ' i d e a l ' c o n d i t i o n s a r e met i n a 26 growout f a c i l i t y , o f t e n growth i s e x p r e s s e d i n terms of inches/month, months u n t i l m a r k e t a b l e s i z e , or c o n v e r s i o n r a t i o (wet weight f e e d t o wet weight f i s h . ) . Maximum r a t e s of growth are m a i n t a i n e d by e n s u r i n g the b e s t p o s s i b l e p h y s i c a l growing environment, then f e e d i n g the f i s h a c c o r d i n g t o p r e - e s t a b l i s h e d f e e d i n g nomograms or t a b l e s which r e l a t e the f i s h ' s s p e c i e s , age ( s i z e ) and water temperature t o recommended d a i l y r a t i o n , based on p r e v i o u s f e e d i n g t r i a l s f o r the same r a t i o n . (Bardach et a l . , 1972; Ewos, 1982). Johnson (1974) t r a n s l a t e d a f i s h growth model i n t o a computer program which s i m u l a t e s the growth of s a l m o n i d s . S i n c e the aim of s p o r t f i s h h a t c h e r i e s i s t o produce the r i g h t s i z e and number of f i s h a t the r i g h t time f o r s t o c k i n g , r a t h e r than t o produce the l a r g e s t f i s h as f a s t as p o s s i b l e , Johnson's HATCH program recommends d e v i a t i o n s from optimum c o n d i t i o n s a t c e r t a i n p o i n t s i n the management of the h a t c h e r y , t o slow the f i s h growth. e. H e a l t h The o c c u r r e n c e of d i s e a s e i n r e a r e d f i s h i s a v e r y s e r i o u s problem i n the i n d u s t r y ( H e s t e r , 1973) and i s u s u a l l y a c o m b i n a t i o n of c o n t r i b u t i n g f a c t o r s ( F i g u r e 4 ) . The s t a t e of h e a l t h of the f i s h , c o u p l e d w i t h poor r e a r i n g c o n d i t i o n s make the f i s h s u s c e p t i b l e t o i n f e c t i o n by pathogens. Poor f i s h c o n d i t i o n may be the r e s u l t of h a n d l i n g , crowding or inadequate or i n s u f f i c i e n t d i e t . E n v i r o n m e n t a l s t r e s s may be caused by poor p h y s i c a l c o n d i t i o n s , such as low oxygen or h i g h t o x i c m e t a b o l i t e c o n c e n t r a t i o n s , too h i g h or too low t e m p e r a t u r e s , or 27 Figure 4 . I n t e r r e l a t i o n s h i p of disease causing factors(Wedemeyer et a l . , 19 76). Habitat and feeding niches of the principal species in classical Chinese carp culture. (1) Crass carp (Ctenopharyngodon ideilus) feeding on vegetable (ops. (2) Big head (Aristichtys nobilis) feeding on zooplankton in midwatcr: (3) Silver carp (Hypoph-Ihalmichtys molitrix) feeding on phytoplankton in midwatcr. (4) Mud carp (Cirrhinus molilorella) feeding on benthic animals and detritus, including grass carp feces. (5) Common carp (Cyprinus earpio) feeding on benthic animals and detritus, including grass carp feces. (6) Black carp (Mylopharyngodon piceus) feeding on mollusks. Figure 3. Polyculture example(from Bardach, Ryther and McLarney, 19 72) . 28 excess i o n s or p o l l u t a n t s (Wedemeyer, 1976). The pathogen may be v i r a l , b a c t e r i a l , f u n g a l or p a r a s i t i c and may be the major cause of i l l h e a l t h or j u s t a secondary i n f e c t i o n on an a l r e a d y s i c k f i s h . F u n g a l and p a r a s i t i c d i s e a s e s u s u a l l y d e v e l o p q u i t e s l o w l y but v i r a l and b a c t e r i a l d i s e a s e s agents can reproduce themselves v e r y r a p i d l y and be e p i z o o t i c i n poor c o n d i t i o n s b e f o r e the farmer has much chance of r e c o g n i z i n g the f i r s t symptoms (Amlacher, 1970). P r e d a t i o n by b i r d s , mammals and r e p t i l e s can be a problem on f i s h farms, p a r t i c u l a r l y s i n c e most of i t w i l l o c cur when the farmer i s not p r e s e n t . To be on the s a f e s i d e farmers tend to expect such p r e d a t i o n , t o l o o k out f o r burrows or r u n s , and to fence i n t h e i r ponds, s e t t r a p s and s t r i n g up w i r e s or m i s t n e t s t o d i s c o u r a g e p r e d a t o r s . The key p r o p h y l a x i s a g a i n s t f i s h h e a l t h problems i s t o f o r e s e e any p o t e n t i a l problems and c o r r e c t them b e f o r e they can de v e l o p i n t o d i s e a s e e n c o u r a g i n g s i t u a t i o n s . The f i r s t concern i s t o p r o v i d e as happy a home f o r the f i s h as i s p o s s i b l e . T h i s means a c l e a n house, good f o o d , c o o l , c l e a n water and s u f f i c i e n t space f o r e x e r c i s e . The next s t e p i s t o have a d e f e n s i v e s t r a t e g y towards any p o s s i b l e i n f e c t i o n . T h i s s t r a t e g y depends e n t i r e l y on the l i f e h i s t o r y of the pathogen. The farmer need o n l y i n t e r r u p t t h a t l i f e h i s t o r y a t one p o i n t to get r i d of the pathogen (Sinderman, 1966). For example s e v e r a l worm p a r a s i t e s r e q u i r e i n t e r m e d i a t e s n a i l h o s t s i n t h e i r development, thus keeping s n a i l s out of the water source s h o u l d keep out the worms. The t h i r d s t e p i s p r e v e n t a t i v e 29 maintenance. T h i s i n v o l v e s p e r i o d i c t r e a t m e n t f o r d i s e a s e s which a r e l i k e l y t o be p r e s e n t , but i n such low c o n c e n t r a t i o n s as t o be not y e t d e t e c t e d . A good example of t h i s i s the r o u t i n e t r e a t m e n t of f r e s h eggs w i t h f u n g i c i d e , s i n c e t h e r e i s no p r a c t i c a l way t o keep f u n g a l spores away from the eggs ( L e i t r i t z and L e w i s , 1976). C. Canadian A q u a c u l t u r e a. S t a t u s A l t h o u g h a q u a c u l t u r e may be l o c a l l y i m p o r t a n t i n some ar e a s of Canada, e s p e c i a l l y t o the s m a l l number of f i s h f a r m e r s , i t i s f a r from b e i n g a major c o n t r i b u t o r t o Canadian y i e l d s of f i s h e r y p r o d u c t s . The t o t a l Canadian f i s h e r y y i e l d i n 1972 was e s t i m a t e d a t 1 MMT, i n c l u d i n g 900 MT from a q u a c u l t u r e , of which 350 MT were s o l d f o r human consumption (MacCrimmon et a l . , 1974). In the M a r i t i m e p r o v i n c e s , a v e r y f i s h e r y - o r i e n t e d r e g i o n , t h e r e i s some c u l t u r e of seaweeds, more of s h e l l f i s h and some e x p e r i m e n t a l programs of t r o u t and A t l a n t i c salmon c u l t u r e i n ponds and cages ( S m i t h , 1962). O n t a r i o and Quebec both have v e r y e x t e n s i v e s p o r t f i s h h a t c h e r y s t o c k i n g programs and a l s o have l a r g e f i s h f a r m i n g ( m o s t l y t r o u t ) a s s o c i a t i o n s w i t h over 100 l i c e n s e d p r o d u c e r s per P r o v i n c e ( A y l e s , 1978). P r o d u c t i o n of t a b l e t r o u t , coming from o n l y 3-4 major p r o d u c e r s , i s s t i l l w e l l below the market demand (Beamish et a l . , 1975). 30 The P r a i r i e P r o v i n c e s a l l have s p o r t f i s h s t o c k i n g programs but the most e x c i t i n g development i n the l a s t t e n y e a r s i s the study and encouragement of ' p o t h o l e f a r m i n g ' . T h i s i n v o l v e s the s t o c k i n g w i t h f i n g e r l i n g t r o u t i n t o s m a l l l a k e s which tend t o w i n t e r - k i l l ( a l l the f i s h d i e i n the w i n t e r from l a c k of oxygen i n the water, due t o i c e f o r m a t i o n b l o c k i n g m i x i n g w i t h the a i r ) but produce l a r g e p o p u l a t i o n s of gammarid amphipods, an i d e a l f i s h f o o d . By summer's end the t r o u t a r e market s i z e (25+ cent i m e t e r s ) . In B r i t i s h Columbia, the P r o v i n c i a l F i s h and W i l d l i f e Branch has a c o n t i n u i n g program of s u p p o r t i n g the s p o r t f i s h e r y of v a r i o u s f r e s h w a t e r s a l m o n i d s by p r o t e c t i n g and i m p r o v i n g stream and l a k e h a b i t a t s , and b u i l d i n g spawning c h a n n e l s and h a t c h e r i e s t o i n c r e a s e r e c r u i t m e n t of w i l d s t o c k or t o p l a n t h a t c h e r y s t o c k s i n f i s h f r e e a r e a s ( P a r k i n s o n and S l a n e y , 1975). P r e s e n t l y the Branch s t o c k s about 3.5 m i l l i o n t r o u t of v a r i o u s s i z e s per year i n t o n a t u r a l waters throughout the P r o v i n c e ( F i s h and W i l d l i f e B r a nch, 1982). Freshwater f i s h f a r m i n g i n B. C. i s a s m a l l i n d u s t r y , w i t h o n l y one major p r o d u c e r , the o t h e r 20 l i c e n c e e s b e i n g p a r t - t i m e o p e r a t i o n s ( E n v i r o c o n L i m i t e d , 1984). The F e d e r a l Government's P a c i f i c B i o l o g i c a l S t a t i o n a t Nanaimo has an a q u a c u l t u r e program which has done some work on net-pen c u l t u r e of salmon and s a b l e f i s h , but has now phased out most of t h i s o p e r a t i o n . I n s t e a d , a new a q u a c u l t u r e r e s e a r c h s t a t i o n i s e x p e c t e d t o open on the grounds of the P a c i f i c B i o l o g i c a l S t a t i o n , which w i l l p r o v i d e p r i v a t e i n v e s t o r s w i t h the f a c i l i t i e s t o c a r r y out 31 r e s e a r c h under the d i r e c t i o n of s c i e n t i f i c s p e c i a l i s t s . Sea pen c u l t u r e has a few a c t i v e proponents i n the p r i v a t e s e c t o r , who must compete w i t h h a t c h e r y s t o c k i n g programs f o r f r y ( s i n c e i t i s i l l e g a l t o c o l l e c t eggs from the w i l d ) and w i t h commercial f i s h e r m e n f o r markets. There i s c o n s i d e r a b l e c o n t r o v e r s y as t o whether c u l t u r i s t s of f r e s h or seawater f i s h a r e i n v a d i n g the e x c l u s i v e r i g h t s of commercial and s p o r t f i s h e r m e n t o h a r v e s t the ' p u b l i c ' r e s o u r c e of f i s h . Canadians a r e not v e r y l a r g e f i s h e a t e r s , per c a p i t a consumption b e i n g 5-6 kg/year ( S t a t i s t i c s Canada, 1974). T h i s k i n d of market survey o n l y measures what j j ; r a t h e r than what c o u l d be. In today's p r o g r e s s i v e Western s o c i e t y , new, p r e v i o u s l y unheard of commodities e n t e r the market v e r y f r e q u e n t l y , w i t h tremendous a c c e p t a n c e s u c c e s s . S i n c e the c o n s t r a i n t s t o f i s h p r o d u c t m a r k e t i n g which caused a bad r e p u t a t i o n f o r f i s h e r y p r o d u c t s - - s h o r t s h e l f l i f e , l a c k of i n f o r m a t i o n on p r e p a r a t i o n - - a r e no l o n g e r a p p l i c a b l e , the major cause of low f i s h consumption may o n l y be low s u p p l y and unfami 1 i a r i t y . b. P o l i c y The F e d e r a l Government has a s t a n d i n g p o l i c y "aimed a t r e v i t a l i z i n g a l l branches of Canada's commercial f i s h e r i e s " (Department of F i s h e r i e s and Environment, 1976). C o n c u r r e n t w i t h t h i s theme, as r e g a r d s a q u a c u l t u r e , a r e the Canadian C e n t r e of I n l a n d Water s t u d i e s on P r a i r i e p o t h o l e f a r m i n g and the P a c i f i c B i o l o g i c a l S t a t i o n ' s sea-pen c u l t u r e programs 32 (Kennedy, 1975). There i s p r e s e n t l y no comprehensive Canadian F e d e r a l a q u a c u l t u r e p l a n ( P r i t c h a r d , 1976) comparable t o t h a t of the U n i t e d S t a t e s (Glude, 1977). F i s h f a r m i n g i s m o s t l y r e g u l a t e d by the P r o v i n c i a l Governments' s p o r t f i s h a g e n c i e s , Ottawa h a v i n g l e f t much of the j u r i s d i c t i o n of f r e s h w a t e r f i s h f a r m i n g up t o the P r o v i n c e s , s i n c e the P r o v i n c e s c o n t r o l l a n d use, water r i g h t s , p o l l u t i o n , and s p o r t f i s h c u l t u r e , the a r e a s most i n t i m a t e l y c o n n e c t e d w i t h f i s h f a r m i n g . O n t a r i o has a l a r g e f i s h f a r m i n g lobby and thus the problems w i t h l e g a l r i g h t s of f i s h farmers a r e m i n i m a l compared t o the c l i m a t o l o g i c a l problems. The P r a i r i e farmers who engage i n p o t h o l e f a r m i n g a r e the major p o l i t i c a l s t r e n g t h of those P r o v i n c e s and have t h e i r r i g h t s w e l l p r o t e c t e d . B. C. has the l e a s t r e p r e s e n t a t i o n f o r f i s h f a r m i n g , s i n c e the s p o r t and commercial f i s h i n d u s t r i e s a r e both very p o w e r f u l and the f i s h f a r m e r s ' a s s o c i a t i o n o n l y c o n t a i n s a few members. F i s h f a r m i n g i n B. C. has u s u a l l y been d i s c o u r a g e d beyond the hobby farm s t a g e , the reasons g i v e n b e i n g the p o t e n t i a l danger of e p i z o o t i c s t o n a t u r a l p o p u l a t i o n s and the low p r o b a b i l i t y of s u c c e s s . No f i s h c u l t u r e i s a l l o w e d i n any n a t u r a l body of f r e s h water, no m a t t e r how remote or i n a c c e s s i b l e t o the p u b l i c ( F i s h and W i l d l i f e Branch, 1971). More p e o p l e are g e t t i n g i n v o l v e d i n t r o u t f a r m i n g , however, and t h e r e i s a w e l l l a i d out p e r m i t p r o c e s s i n p l a c e ( T i l l a p a u g h and Edwards, 1980). 33 c. B. C. P o t e n t i a l The g e n e r a l r a t i o n a l e f o r the development of f i s h c u l t u r e i n B. C. i s t h a t f i s h do grow w e l l i n B. C. w a t e r s . The l a r g e f r e s h w a t e r s p o r t f i s h i n d u s t r y ($180 m i l l i o n per y e a r , a c c o r d i n g t o the B. C. W i l d l i f e F e d e r a t i o n ) i s based on t h i s f a c t and many l a k e s , when s t o c k e d w i t h f r y i n s p r i n g , can be ex p e c t e d t o produce t a b l e s i z e d t r o u t by l a t e summer, a growth r a t e t h a t i s hard t o match i n i n t e n s i v e f i s h f a r m i n g c o n d i t i o n s ( V i e r k e , 1978 p e r s . comm.). C e r t a i n l y the P a c i f i c c o a s t , from the F r a s e r v a l l e y Lower M a i n l a n d n o r t h t o P r i n c e R u p e r t , has the m i l d e s t c l i m a t e i n Canada and a . m i l d , temperate c l i m a t e i s i d e a l f o r s a l m o n i d c u l t u r e . The major c o n s t r a i n t s t o a q u a c u l t u r e i n B. C. have been: i ) I n s t i t u t i o n a l 1. F i s h f a r m i n g was not c o n s i d e r e d a s e r i o u s i n d u s t r y and no i n d u s t r i a l development a i d i n the form of g r a n t s or l o a n s was a v a i l a b l e . However i t had a change i n s t a t u s i n 1978 which made i t e l i g i b l e f o r some farm c r e d i t under the B. C. M i n i s t r y of A g r i c u l t u r e but not under A g r i c u l t u r e Canada ( H a c k e t t , 1980). There a r e now s e v e r a l g e n e r a l s m a l l b u s i n e s s development i n c e n t i v e s which c o u l d be u s e f u l t o f i s h farmers a v a i l a b l e from the F e d e r a l and P r o v i n c i a l governments. 2. D i s e a s e r e g u l a t i o n s (Department of F i s h e r i e s and Environment, 1977) r e q u i r e heavy s a m p l i n g and e x t e n s i v e i n v e s t i g a t i o n b e f o r e d i s e a s e c e r t i f i c a t i o n i s g i v e n , a l t h o u g h m a r k e t i n g i s not s e r i o u s l y impeded. 34 3. P o l l u t i o n c o n t r o l l e g i s l a t i o n may r e q u i r e a l l farms t o have p o l l u t i o n abatement systems, no matter how low n u t r i e n t c o n c e n t r a t i o n s are i n the e f f l u e n t water, s i n c e the r e g u l a t i o n s are based on r e g u l a t i n g the amount of p o l l u t i o n per f i s h (Marr, 1975), which i s l i k e t r y i n g t o r e g u l a t e the f i s h ' s m e t a b o l i c p r o c e s s e s . 4. The s e l e c t i o n of a ' l e a d agency' or s i n g l e government body t o c o o r d i n a t e , promote, study and r e g u l a t e the development of an a q u a c u l t u r e i n d u s t r y a c r o s s Canada s t i l l needs t o be d e c i d e d upon i f such development i s t o proceed smoothly. D i f f e r e n c e s i n F e d e r a l / P r o v i n c i a l j u r i s d i c t i o n a l c o n v e n t i o n s i n d i f f e r e n t p a r t s of the c o u n t r y have made t h i s problem u n s o l v a b l e t o d a t e . i i . C l i m a t i c . 1. Nowhere n B. C. i s the a n n u a l mean temperature as h i g h as 15°C, the optimum f o r t r o u t f a r m i n g , which means t h a t r e g a r d l e s s of water s o u r c e , the water temperature a t some time of the year w i l l be below optimimum f o r growing. Most of the s u r f a c e waters i n the P r o v i n c e f r e e z e f o r one t o f o u r months each y e a r , which makes growing f i s h i n them more d i f f i c u l t . i i i . Market 1. The p o t e n t i a l market f o r f i s h p r o d u c t s i n B. C. i s c o n s i d e r a b l e . A c c o r d i n g t o a d e t a i l e d market study c a r r i e d out by Ference (1983), the market f o r p a n - s i z e d rainbow t r o u t c o u l d be more than d o u b l e d , from 73000 kg t o 160000 kg, a n n u a l l y . There w i l l always be a p r e f e r e n c e f o r 35 c e r t a i n imported f i s h but the pe r c e n t a g e of the import market t h a t can be taken over by l o c a l p r o d u c t i o n depends more on the w h o l e s a l e / r e t a i l network and p r o d u c t i o n r e l i a b i l i t y than on f a c t o r s i n v o l v i n g the f i s h f a r m e r s . In 1977 and 1982, Canada impo r t e d $3.0 m i l l i o n and $3.5 m i l l i o n worth of t r o u t , r e s p e c t i v e l y . Development of a q u a c u l t u r e i n B. C. was e x p e c t e d by Pearce Bowden and E n v i r o c o n (1975) t o be a v e r y slow, n o n - s p e c t a c u l a r p r o c e s s . T h i s pessimism i s based m o s t l y on the p a u c i t y and remoteness of s i t e s which would p r o v i d e i d e a l y e a r - r o u n d growing c o n d i t i o n s , as a r e found i n the Snake R i v e r v a l l e y of Idaho ( K l o n t z and K i n g , 1974), and on the l a c k of i n t e r e s t by p o s s i b l e f i n a n c i a l s u p p o r t e r s . F r a l i c k ' s ) 1980) a n a l y s i s of a h y p o t h e t i c a l sea pen farm c o n c l u d e d t h a t such an e n t e r p r i s e s h o u l d be p r o f i t a b l e i f w e l l managed. Beamish e t a l . (1975) proposed a modular concept f o r a q u a c u l t u r e development i n O n t a r i o , which would be even more a p p l i c a b l e t o B. C. The p r o p o s a l i n c l u d e s s e v e r a l t y p e s of f a c i l i t i e s — f o r b r o o d s t o c k , h a t c h e r y , r e a r i n g and p r o c e s s i n g — i n s t e a d of m u l t i p u r p o s e f a c i l i t i e s . In B. C. the m i l d but crowded Lower M a i n l a n d would be i d e a l f o r b r o o d s t o c k and h a t c h e r y f a c i l i t i e s , w h i l e the warm water and l a r g e a r e a needed f o r r e a r i n g c o u l d be found i n the I n t e r i o r d u r i n g the summer. C o l d w i n t e r c o n d i t i o n s i n the I n t e r i o r would p r o v i d e s t o r a g e of the f i s h ( a l i v e or p r o c e s s e d ) u n t i l they were t o be marketed. 36 D. Salmonid C u l t u r e a. I n t r o d u c t i o n The term s a l m o n i d i n a q u a c u l t u r e r e f e r s t o the s u b - f a m i l y Salmoninae, i n c l u d i n g salmon, t r o u t and char (Salmo, Onchorhynchus and S a l v e l i n u s i n N o r t h America) as opposed t o the f a m i l y Salmonidae, which a l s o i n c l u d e s w h i t e f i s h e s and g r a y l i n g s ( S c o t t and Crossman, 1973). The s p e c i e s most o f t e n c u l t u r e d are the t r o u t s (Rainbow, Lake, Brook, Brown) i n f r e s h water f o l l o w e d by the A t l a n t i c and P a c i f i c salmons i n seawater. T h i s s e c t i o n w i l l d e a l w i t h the most c u l t u r e d s a l m o n i d , Rainbow Trout (Salmo g a i r d n e r i , R i c h a r d s o n ) , a l t h o u g h the taxonomic c l o s e n e s s of s a l m o n i d s makes much of what i s s a i d about Rainbow Tro u t a p p l i c a b l e t o the o t h e r s p e c i e s . The pros of f a r m i n g s a l m o n i d s are t h e i r r a p i d growth and h i g h feed c o n v e r s i o n r a t e s when fe d s u f f i c i e n t l y , t h e i r t o l e r a n c e of v e r y crowded c o n d i t i o n s and the market v a l u e of the f l e s h i n terms of q u a l i t y and d o l l a r v a l u e . The cons of f a r m i n g s a l m o n i d s are the s t r i n g e n t water q u a l i t y c r i t e r i a r e q u i r e d ( L i a o , 1971, D a v i s , 1975, Sigma, 1983) and t h e i r s u s c e p t i b i l i t y , e s p e c i a l l y i n crowded c o n d i t i o n s , t o e p i z o o t i c s (mass, f a t a l d i s e a s e o u t b r e a k s ) . Another d i s a d v a n t a g e may be c o m p e t i t i o n w i t h the l a r g e w i l d - c a u g h t salmon market and the s p o r t f i s h e r y , but the v a l i d i t y of such c o m p e t i t i o n has not been proven. 37 b. E x t e n s i v e C u l t u r e S t o c k i n g p r a i r i e p o t h o l e s ( s m a l l s h a l l o w l a k e s ) w i t h t r o u t was i n i t i a t e d t o t a k e advantage of the tremendous n a t u r a l p r o d u c t i v i t y caused by the s h a l l o w n e s s , warmth, n u t r i e n t r i c h n e s s and l a c k of f i s h i n t h e s e l a k e s ( M i l l e r and Thomas, 1964). Any f i s h p o p u l a t i o n s d i e out when the w i n t e r i c e cover s t o p s l a k e c i r c u l a t i o n , and r e s p i r a t i o n and decay use up a l l of the l a k e ' s d i s s o l v e d oxygen (Johnson et a l . , 1970). Farmers whose l a n d s u r r o u n d s the p o t h o l e s purchase t r o u t f i n g e r l i n g s i n the l a t e s p r i n g and s t o c k them a t the r a t e of 200-500 f i s h per a c r e depending on water q u a l i t y , depth and water exchange or a e r a t i o n . The f i s h grow at a r a t e of between 2-3 c e n t i m e t e r s per month, so a t the end of a s i x month growing season (May-October) i n i t i a l 5-7 c e n t i m e t e r f i n g e r l i n g s are 23-30 c e n t i m e t e r s l o n g , w e i g h i n g an average 300-400 grams. The food of these f i s h i s m o s t l y the f r e s h w a t e r amphipod (shrimp) Gammarus l a c u s t r i s ( L a w l e r e t a l . , 1974). Y i e l d s have not been as h i g h as were o r i g i n a l l y expected i n t h i s new i n d u s t r y . Farmers have many d i s a s t r o u s problems r e s u l t i n g i n l a r g e l o s s e s of f i s h . Lakes t h a t t e n d t o w i n t e r -k i l l a r e a l s o s u s c e p t i b l e t o s u m m e r - k i l l , where the decay of a p h y t o p l a n k t o n bloom d e p l e t e s the oxygen. The i n d u s t r y has a l s o s u f f e r e d from poor m a r k e t i n g s t r u c t u r e and l a c k of e x p e r t i s e . Many y i e l d s have not been r e p o r t e d , as they a r e consumed i n p r i v a t e use or as a n g l i n g c a t c h , and f i s h i n g out methods are f a r from o p t i m a l ( D u t h i e and F l e t t , 1974). There i s s t i l l a g r e a t p o t e n t i a l i n p o t h o l e f a r m i n g 38 a l t h o u g h i t i s not as easy as i t appeared i n i t i a l l y , and w i t h c a r e f u l , i n t e l l i g e n t management some c o n s i d e r a b l e c o n t r i b u t i o n t o t o t a l t r o u t p r o d u c t i o n may be ex p e c t e d from t h i s source ( A y l e s , 1978). c. I n t e n s i v e C u l t u r e T r o u t raceway c u l t u r e i s a v e r y w e l l e s t a b l i s h e d a r t and s c i e n c e i n N o r t h A merica, Europe and Japan. T r o u t have always been a p o p u l a r s p o r t f i s h and have e x c e p t i o n a l t a b l e q u a l i t i e s of t a s t e , t e x t u r e and appearance. C u l t u r e s t a r t s w i t h i n c u b a t i o n of eggs o b t a i n e d from s t r i p p i n g domestic or w i l d - c a u g h t b r o o d - s t o c k and i n s e m i n a t i n g by the d r y method, g i v i n g 95% f e r t i l i z a t i o n ( L e i t r i t z and L e w i s , 1976). Parent s t o c k i s u s u a l l y chosen f o r o u t w a r d l y e v i d e n t d e s i r a b l e c h a r a c t e r i s t i c s such as body s i z e , d e p t h , f i r m n e s s , c o l o u r and h e a l t h . A l t h o u g h such ' s e l e c t i v e b r e e d i n g ' u s i n g a s m a l l number of p a r e n t s s h o u l d soon show marked i n b r e e d i n g i n the gene p o o l , t h e r e i s l i t t l e c o n c r e t e e v i d e n c e of e i t h e r p o s i t i v e or n e g a t i v e e f f e c t s which can be d i r e c t l y a t t r i b u t e d t o g e n e t i c c a u s e s . A f t e r i n c u b a t i n g i n c o l d , w e l l oxygenated water f o r 3 t o 5 weeks the eggs h a t c h i n t o y o l k - s a c f r y c a l l e d a l e v i n s . L a t e r (3 t o 4 weeks) when the y o l k - s a c has been a b s o r b e d , the f i s h a re c a l l e d swim-up f r y and a r e ready t o f e e d on f i n e - g r o u n d , h i g h p r o t e i n f e e d . The f r y grow v e r y r a p i d l y a t t h i s s t a g e , p r o g r e s s i v e l y b e i n g f e d l a r g e r and l a r g e r s i z e d food p a r t i c l e s or p e l l e t s as they grow t o the f i n g e r l i n g (5 t o 10 cm) s t a g e . R e a r i n g of f r y s t a r t s out i n 39 e l e v a t e d t r o u g h s , but as the f i s h get l a r g e r they a r e t r a n s f e r r e d t o c i r c u l a r or r e c t a n g u l a r raceways or ponds. Feeding i s done e i t h e r by hand or u s i n g a u t o m a t i c , t i m e r a c t i v a t e d f e e d i n g machines. The amount f e d per day depends on the f i s h s i z e , water temperature and r a t i o n c o m p o s i t i o n , and can be c a l c u l a t e d from t a b l e s or formulae worked out by s e v e r a l workers (Bardach e t a l . , 1972; H a s k e l l , 1959; Westers, 1981). When the f i s h have reached near market s i z e , t h e i r f e e d i n g r a t e i s reduced t o a maintenance r a t i o n , a t which they remain u n t i l t hey a re r e q u i r e d f o r h a r v e s t and p r o c e s s i n g . A s e l e c t p r o p o r t i o n of the r e a r e d p o p u l a t i o n i s s e t a s i d e t o c o n t i n u e t o grow beyond market s i z e f o r an o t h e r year or two, when they can be used as the new brood s t o c k . D i s e a s e p r e v e n t i o n i n c l u d e s c o n t i n u a l o b s e r v a t i o n of the apparent h e a l t h of the f i s h as shown by t h e i r swimming b e h a v i o r and c o n d i t i o n as w e l l as p r o p h y l a c t i c t r e atment w i t h d i s i n f e c t a n t s at s u s c e p t a b l e ages or seasons (Roberts and Shepherd, 1974; Wood, 1974). B e l l and M a r g o l i s (1976) r e v i e w e d the p a r t i c u l a r d i s e a s e problems e n c o u n t e r e d i n the P a c i f i c Region of Canada, l e a d i n g t o a s t r i c t f i s h h e a l t h program which i s among the most comprehensive i n the w o r l d (Department of F i s h e r i e s and Environment, 1977). P o l l u t i o n from t r o u t farms has been of some concern ( L i a o , 1970; Mayo and L i a o , 1969), a l t h o u g h f o r water t o be s u i t a b l e f o r r e a r i n g t r o u t , i t must be r e l a t i v e l y c l e a n anyway. S e t t l i n g ponds are f r e q u e n t l y i n s t a l l e d i n the t a i l w a ters of farms nowadays, t o s e t t l e out the suspended s o l i d s and a c t as a 40 p r i m a r y sewage tr e a t m e n t system ( J e n s e n , 1972). More e f f e c t i v e systems are a v a i l a b l e ( L i a o , 1970) but are u s u a l l y a p p l i e d o n l y when a l a r g e amount of e f f l u e n t i s e n t e r i n g a s m a l l w a t e r c o u r s e . E. Other F i s h e s The marine f i s h e r y i s p r e s e n t l y dominated i n tonnage lan d e d by f i s h e s such as the a n c h o v e t t a and the a l a s k a n p o l l a c k which were not t r a d i t i o n a l l y h a r v e s t e d , but whose tremendous p r o d u c t i o n has encouraged us t o f i n d uses f o r them. The same phenomenon has o c c u r r e d i n the f r e s h w a t e r environment, when some very p r o d u c t i v e y e t p r e v i o u s l y u n d e s i r a b l e f i s h have become v a l u a b l e . The appearance of the a l e w i f e i n the G r e a t Lakes a f t e r the W e l l a n d C a n a l was b u i l t was f i r s t c o n s i d e r e d a n u i s a n c e but now the a l e w i f e c o m p r i s e s the l a r g e s t c a t c h i n an o t h e r w i s e f a i l i n g f i s h e r y ( C a b l e , 1971). Perhaps a q u a c u l t u r i s t s can l e a r n a l e s s o n from t h e s e examples. A review of the c h a r a c t e r i s t i c s of a f i s h which make i t d e s i r a b l e f o r c u l t u r e w i l l h e l p c l a r i f y which f i s h are s u i t a b l e . R a p i d growth r a t e i s p r o b a b l y the most i m p o r t a n t d e s i r a b l e c h a r a c t e r i s t i c of c u l t u r e d f i s h (Webber and R i o r d e n , 1975). T r a d i t i o n a l l y t h i s has meant t h a t f i s h grow r a p i d l y t o a l a r g e s i z e , a t l e a s t 25 cm. From an e f f i c i e n c y of p r o d u c t i o n s t a n d p o i n t , however, the i m p o r t a n t t h i n g i s t h a t the c u l t u r e d p o p u l a t i o n accumulate a l a r g e biomass w i t h i n a s h o r t t i m e . An example from a g r i c u l t u r e w i l l h e l p c l a r i f y t h i s p o i n t . I t t a k e s 41 one 1300 pound s t e e r 120 days t o eat 1 ton of hay, r e s u l t i n g i n 240 pounds of weight g a i n . However, 300 r a b b i t s .could g a i n the same 240 pounds of weight from 1 ton of hay i n o n l y 30 days ( K l e i b e r , 1961). S m a l l e r a n i m a l s have s h o r t e r l i f e c y c l e s and i n c r e a s e t h e i r numbers f a s t e r than l a r g e r a n i m a l s . Some aquarium f i s h e s can have broods e v e r y 2 weeks, whereas salmon must w a i t 2 t o 5 y e a r s f o r t h e i r f i r s t brood and h a l i b u t must w a i t 8 t o 16 y e a r s . F i s h a l s o grow f a s t e r when they a r e younger, so even w i t h i n a s p e c i e s i t i s more e f f i c i e n t t o grow many young than a few o l d f i s h , i n terms of r a p i d biomass a c c u m u l a t i o n . Feed c o n v e r s i o n e f f i c i e n c y i s v e r y i m p o r t a n t as the c o s t of feeds i n c r e a s e s . F i s h e s have d i f f e r e n t m e t a b o l i c r e q u i r e m e n t s and v i t a m i n s y n t h e s i s a b i l i t y , thus some f i s h can l i v e b e t t e r on poorer q u a l i t y (cheaper) food than o t h e r s . Lu and Kevern (1975) f e d d r i e d p o u l t r y manure as p a r t of the d i e t t o c h a n n e l c a t f i s h and g o l d f i s h w i t h c o n s i d e r a b l e s u c c e s s , and Moav et a l . (1977) s u b s t i t u t e d l i q u i d cow manure t o c a r p , t i l a p i a , s i l v e r c a r p and g r a s s c a r p i n p o l y c u l t u r e and noted a decrease i n body f a t c o m p o s i t i o n w i t h o u t a d e c r e a s e i n growth r a t e . No-one s e r i o u s l y s u g g e s t s t h a t salmonids c o u l d grow on wastes a l t h o u g h many f i l l e r s have been used (such as sawdust, and paper) i n t h e i r d i e t s and t h e r e i s a c o n t i n u i n g s e a r c h f o r a cheap source of food energy i n t r o u t feeds so t h a t more of the p r o t e i n w i l l be c o n v e r t e d t o p r o t e i n f l e s h r a t h e r than b e i n g m e t a b o l i z e d . A r a t i o n a l approach t o f e e d i n g e f f i c i e n c y i s to c u l t u r e h e r b i v o r o u s or omnivorous f i s h , s i n c e v e g e t a b l e 42 m a t t e r i s so much cheaper t o s u p p l y or grow than i s the h i g h p r o t e i n a n i m a l m a t t e r needed i n t r o u t f e e d s . There has been i n t e r e s t i n b r e e d i n g an h e r b i v o r o u s t r o u t , which may or may not be p o s s i b l e , but a more r a t i o n a l approach would be t o c u l t i v a t e a l r e a d y h e r b i v o r o u s f i s h e s . The g r a s s c a r p i s a p o p u l a r A s i a n f i s h which seems t o make good use of any s o f t v e g e t a b l e matter ( a l g a e , g r a s s c l i p p i n g s ) but the problems of i n d e t e r m i n a t e e c o l o g i c a l e f f e c t s , q u a r a n t i n e and p o s s i b l e escape t o the w i l d p r o h i b i t i m p o r t a t i o n . There are some n a t i v e B. C. h e r b i v o r o u s f i s h e s whose c u l t u r e p o s s i b i l i t i e s would be i n t e r e s t i n g t o i n v e s t i g a t e ( S c o t t and Crossman, 1973). The main reason t h a t l a r g e , r e l a t i v e l y b o n e - f r e e f i s h have been p r e f e r r e d f o r c u l t i v a t i o n i n the p a s t i s t h a t the f i s h must be t a b l e a c c e p t a b l e . Methods i n deboning c o a r s e f i s h and making the f l e s h i n t o f i s h cakes have been p e r f e c t e d by marine f i s h p r o c e s s o r s and d e l i c i o u s , i f not p a r t i c u l a r l y f i s h -a p p e a r i n g , p r o d u c t s have been d e v e l o p e d (Burgess et a l . , 1965). F i s h which cannot be used f o r human f o o d , or s c r a p p a r t s from the f i s h p r o c e s s i n g , a r e s t i l l v a l u a b l e f o r use i n f i s h o i l and f i s h meals, used f o r i n d u s t r i a l purposes or as h i g h p r o t e i n a n i m a l f e e d supplements,. The p r e s e n t c o s t of a n i m a l feeds i s h i g h ($400 t o $500 per t o n , B i s s e l C o n s u l t a n t s , 1974), and farmers may f i n d i t b e n e f i c i a l t o grow t h e i r own meal f i s h i n manure f e r t i l i z e d ponds. 43 F. Lower T r o p h i c C u l t u r e The r a t i o n a l e f o r c u l t u r i n g a n i m a l s low on the food c h a i n , t o be used as food items f o r the p r o d u c t f i s h , stems from t h r e e a r e a s . F i r s t l y i t i s o f t e n supposed t h a t f e e d i n g f i s h t h e i r ' n a t u r a l ' food i s the best way t o ensure a n u t r i t i o n a l l y b a l a n c e d d i e t and e x p e n s i v e feed f o r m u l a t i o n t e s t s would not be n e c e s s a r y . R e g a r d l e s s of what food a f i s h e a t s , t h a t food must c o n t a i n the proper b a l a n c e of n u t r i t i o n a l r e q u i r e m e n t s ( H a l v e r , 1972). A l b r e c h t and Wunsche (1972) d i s c u s s e d the importance of lower a n i m a l s t o f i s h n u t r i t i o n and c o n c l u d e d t h a t the n u t r i t i o n a l h e a l t h of w i l d f i s h i s p r o b a b l y more dependent on the v a r i e t y of food organisms than on the ' n a t u r a l n e s s ' of them. However, f i s h do grow r a p i d l y on ' n a t u r a l ' f o o d s , whether w i l d (Johnson, et a l . , 1970) or c u l t u r e d (Cure, 1964). Secondly the c o s t : b e n e f i t c o m p a r i s i o n between c u l t u r i n g n a t u r a l food items and b u y i n g e x p e n s i v e a r t i f i c i a l feeds appears a t t r a c t i v e . Coupled w i t h t h i s i s the t h i r d r a t i o n a l e , t h a t i t seems l e s s w a s t e f u l t o grow f i s h on food items c u l t u r e d from manure or o t h e r wastes than t o f e e d them brewers y e a s t , h e r r i n g and shrimp meals and o i l s , and soya meal, a l l items which c o u l d , w i t h some i m a g i n a t i o n , be c o n v e r t e d i n t o foods s u i t a b l e f o r humans. The c o s t of growing i n v e r t e b r a t e s depends g r e a t l y on the a v a i l a b i l i t y of e x t r a pond space and the c u l t u r e system r e l i a b i l i t y , as w i l l be d i s c u s s e d l a t e r , but c e r t a i n l y the c o s t of f e e d i n g manure t o f i s h a t $10 per ton v i a c u l t u r e i s cheaper than f e e d i n g them p r e p a r e d f e e d a t $10 per t e n k i l o s . What organisms a r e c u l t u r e d depends on t h e i r s u i t a b i l i t y 44 as food i t e m s . S u i t a b i l i t y may be n u t r i t i o n a l (what i s good f o r the f i s h ) (Yurkowski and Tabachek, 1978) or b e h a v i o r a l (what they w i l l r e a d i l y e a t ) ( G a l b r a i t h , 1967). I f f i s h e a s i l y l e a r n t o a c c e p t p e l l e t e d f o o d , presumably they w i l l eat a n y t h i n g t h a t i s the r i g h t s i z e f o r them t o see, c a p t u r e and i n g e s t . Wankowski and Thorpe (1979) found A t l a n t i c salmon t o be v e r y s e l e c t i v e of food p a r t i c l e s i z e when g i v e n a c h o i c e . A q u a t i c i n v e r t e b r a t e s which f i t these c r i t e r i a and a l s o which make up a l a r g e p r o p o r t i o n of the n a t u r a l d i e t of t r o u t , a r e c r u s t a c e a n s (amphipods, copepods, c l a d o c e r a n s ) and a q u a t i c i n s e c t l a r v a e ( c h i r o n o m i d s , c h a o b o r i d s , m a y f l i e s ) (Pennak, 1953). Other p r o d u c t i v e i n v e r t e b r a t e s a r e r o t i f e r s , which are m o s t l y too s m a l l f o r t r o u t but c o u l d be p e l l e t e d , and worms, which a r e a b i t b i g but c o u l d be c u t up. A l g a l c u l t u r e has l o n g been done i n s y s t e m a t i c s t u d i e s and more r e c e n t l y l a r g e s c a l e c u l t u r e s have been attempted t o produce cheap p r o t e i n a c e o u s food ( U k e l e s , 1973; S t e n g e l , 1970). Most c u l t u r e of i n v e r t e b r a t e s i s on a l a b o r a t o r y s c a l e i n m i c r o ecosystems ( I v l e v , 1961), s y s t e m a t i c s , b i o a s s a y (Dewey and P a r k e r , 1964), and s m a l l s c a l e f e e d i n g e x p e r i m e n t s (Palmer, et a l . , 1975). The o p e r a t i o n of such c u l t u r e s i s e i t h e r i n s m a l l , h i g h l y c o n t r o l l e d m i c r o c u l t u r e s or i n l e s s c o n t r o l l e d m i n i c u l t u r e s which t r y t o s i m u l a t e more n a t u r a l c o n d i t i o n s . Mass c u l t u r e s a r e i n the m i d i t o super range such as K o n s t a n t i n o v ' s (1973) Chironomus t r a y s or I v l e v a ' s (1973) Daphnia ponds (see Page 47 and 48 f o r d e f i n i t i o n s of c u l t u r e s i z e s ) . Most of the l i t e r a t u r e on mass c u l t i v a t i o n came from N o r t h America i n the 45 1920 1s-1930's, but s i n c e 1960 has m o s t l y been from E a s t e r n Europe. The o p e r a t i o n i n v o l v e s p r e p a r a t i o n of the c u l t u r e medium, i n o c u l a t i o n w i t h a s m a l l number of a n i m a l s , w a i t i n g u n t i l the c u l t u r e reaches peak p r o d u c t i o n , c y c l i c h a r v e s t and r e f e r t i l i z a t i o n , then d e s t r u c t i o n of the c u l t u r e and p r e p a r a t i o n of a new medium. C o n t i n u o u s c u l t u r e s have been m a i n t a i n e d f o r some time on a v e r y s m a l l s c a l e but mass c u l t u r e s seem t o always c r a s h a t some p o i n t . 46 .3. AQUACULTURAL SYSTEM DESIGN A. D e f i n i t i o n s a. G e n e r a l A q u a c u l t u r e has been d e f i n e d i n some d e t a i l i n the p r e c e d i n g s e c t i o n . Design i s "the a c t of c o n c e i v i n g and p l a n n i n g the s t r u c t u r e and parameter v a l u e s of a system, d e v i c e or p r o c e s s " . System d e s i g n i s the " t e c h n i q u e of c o n s t r u c t i n g a system t h a t p e rforms i n a s p e c i f i e d manner, making use of a v a i l a b l e components" (Lapedes, 1974). We can t h e r e f o r e d e f i n e a q u a c u l t u r e system d e s i g n as the t e c h n i q u e of c o n c e i v i n g and p l a n n i n g the c o n s t r u c t i o n of an a q u a t i c p r o d u c t i o n system f a c i l i t y . T h i s d e s i g n a t t e m p t s t o match the p r o d u c t i o n f a c i l i t y (here used i n the meaning of a p l a c e s e t a s i d e t o p r o v i d e a s p e c i a l s e r v i c e ) t o the b i o l o g i c a l r e q u i r e m e n t s of the c u l t u r e d organism w i t h i n the c o n s t r a i n t s of the t o t a l environment of the o p e r a t i n g s i t e . T h i s t o t a l environment i n c l u d e s both the p h y s i c a l / b i o l o g i c a l and the s o c i o / p o l i t i c o / e c o n o m i c e n v i r o n m e n t s . An a q u a c u l t u r e f a c i l i t y may be d e s i g n e d t o f u l f i l l one or more of a v a r i e t y of d i f f e r e n t purposes f o r r e s e a r c h or p r o d u c t i o n . Research f a c i l i t i e s may be i n the form of models, which a r e d e s c r i p t i o n s of the s y s t e m — v i s u a l , p h y s i c a l , g r a p h i c a l , m a t h e m a t i c a l or computer s i m u l a t i o n — w h i c h use an a n a l o g o u s but e s s e n t i a l l y n o n - i d e n t i c a l approach. P i l o t p l a n t s 47 a r e r e s e a r c h f a c i l i t i e s which attempt t o e x a c t l y copy some of the p h y s i c a l parameters which are im p o r t a n t i n the p r o d u c t i o n p r o c e s s but which u s u a l l y c o n t a i n many s c a l i n g i n c o m p a t i b i l i t i e s between the p h y s i c a l and b i o l o g i c a l parameters or among the v a r i o u s p h y s i c a l p a r a m e t e r s . S c a l i n g from p i l o t p l a n t t o f u l l s i z e d o p e r a t i o n may i n v o l v e complex m a t h e m a t i c a l p r o c e d u r e s (Johnstone and T h r i n g , 1957). A p r o t o t y p e i s a f u l l s c a l e p r o d u c t i o n f a c i l i t y which c o n t a i n s o n l y one or two of the modules of the u l t i m a t e m u l t i - m o d u l e o p e r a t i o n , used as a f i n a l t e s t i n g ground of the d e s i g n c o m p a t i b i l i t i e s worked out i n the p l a n n i n g p r o c e s s and the p i l o t p l a n t s t u d i e s . b. S c a l e The u l t i m a t e f a c i l i t y , depending on the purpose a s s i g n e d t o i t , may be of a range of s i z e s . To f a c i l i t a t e d e s c r i p t i o n of d e s i g n s , a group of p r e f i x e s a r e d e f i n e d t o be used i n c o n j u n c t i o n w i t h the s c a l e of p a r t i c u l a r o p e r a t i o n s or d e v i c e s . From s m a l l t o l a r g e t h e s e a r e : 1. M i c r o - - t h i s i s a v e r y s m a l l c u l t u r e , w i t h i n one or two o r d e r s of magnitude l a r g e r than the c u l t u r e d organism. For l a r g e f i s h t h i s would be aquarium s i z e or s m a l l e r , (1 t o 50 i n d i v i d u a l s ) and f o r s m a l l i n v e r t e b r a t e s , l a r g e or s m a l l j a r c u l t u r e , w i t h v e r y few i n d i v i d u a l s (1 t o 100). The p h y s i c a l p r o p e r t i e s of s c a l e a re so d i s t o r t e d a t t h i s s i z e t h a t p r o b a b l y o n l y some b i o l o g i c a l r e l a t i o n s h i p s c o u l d be t r a n s f e r r e d t o f u l l s i z e o p e r a t i o n s . 48 2. ' M i n i — t h i s i s the l e v e l of s m a l l p i l o t p l a n t s , d e s i g n e d f o r t r a n s f e r a b i l i t y of one or two p h y s i c a l d e s i g n p a r a m e t e r s , but s t i l l h i g h l y d i s t o r t e d from a f u l l s c a l e -up p i l o t p l a n t . For l a r g e f i s h t h i s would be s m a l l raceways i n v o l v i n g a s m a l l p o p u l a t i o n (10 t o 1000) or f o r s m a l l i n v e r t e b r a t e s , aquarium or l a r g e bucket s i z e . 3. M i d i - - t h i s i s a s m a l l s c a l e v e r s i o n of the f u l l s i z e p r o d u c t i o n d e s i g n , i n which the p h y s i c a l ( f l o w , water q u a l i t y ) and b i o l o g i c a l ( s t o c k i n g d e n s i t y , f e e d i n g r a t e ) c h a r a c t e r i s t i c s c l o s e l y match those of the i n t e n d e d f i n a l d e s i g n . 4. M a c r o — t h i s i s the f u l l s i z e d p r o d u c t i o n o p e r a t i o n f o r i n t e n s i v e , mass c u l t u r e , the s i z e of most government h a t c h e r i e s , commercial f i s h farms, r a f t or cage c u l t u r e s or i n v e r t e b r a t e pond c u l t u r e s . 5. S u p e r - - t h i s i s the l a r g e s t c o n c e i v a b l e c u l t u r e system f o r an o r g a nism, where t h e r e i s s t i l l a degree of c o n t r o l e x e r t e d on some a s p e c t of the a n i m a l ' s l i f e . R e s e r v o i r f i s h c u l t u r e or complete l a k e i n v e r t e b r a t e c u l t u r e would be i n t h i s group. 49 B. D e s i g n P r o c e s s a. A p p r o a c h e s The d e s i g n of any b i o l o g i c a l p r o d u c t i o n f a c i l i t y i s not a s i n g l e p r o c e s s nor can i t be a p p r o a c h e d from a c o n s i s t e n t v i e w p o i n t . A l o g i c a l d e s i g n s e q u e n c e might be f i r s t t o d e s i g n t h e optimum b i o l o g i c a l r e q u i r e m e n t s ( B i o l o g i c a l D e s i g n ) of t h e s p e c i e s b e i n g r a i s e d , s e c o n d t o s e l e c t f i s h c u l t u r e methods ( O p e r a t i o n s D e s i g n ) w h i c h w i l l b e s t p r o v i d e t h o s e r e q u i r e m e n t s , t h i r d t o p r o v i d e optimum s t r u c t u r e s ( E n g i n e e r i n g D e s i g n ) f o r use i n c a r r y i n g out t h o s e o p e r a t i o n s , and f i n a l l y t o e s t i m a t e how much t h e whole t h i n g i s g o i n g t o c o s t ( E c o n o m i c D e s i g n ) . The c o m b i n a t i o n of B i o l o g i c a l and O p e r a t i o n s D e s i g n s , o r r a t h e r t h e p r o c e s s t h a t l i n k s them, i s t h e P r o d u c t i o n from t h e f a c i l i t y . The O p e r a t i o n s (what must be done) and t h e E n g i n e e r i n g ( s t r u c t u r e s p r o v i d e d ) d e s i g n s a r e l i n k e d t h r o u g h t h e P r o c e s s (how t h i n g s a r e done w i t h t h o s e s t r u c t u r e s ) . T h e s e r e l a t i o n s h i p s a r e diagrammed i n F i g u r e 5. A n o t a b l e f e a t u r e of t h i s d i a g r a m i s t h a t t h e a r r o w s go i n b o t h d i r e c t i o n s . T h i s i s b e c a u s e t h e c o n c e p t f o r a f a c i l i t y c an i n f a c t be i n i t i a t e d a t any p o i n t i n t h e i n t e r r e l a t e d web. F o r example, v e r y o f t e n a p r o j e c t w i l l s t a r t w i t h a c e r t a i n b udget ( E c o n o m i c s ) w h i c h s e t s c o n s t r a i n t s on t h e k i n d o f P r o c e s s w h i c h i s a f f o r d a b l e , d e p e n d e n t on E n g i n e e r i n g and O p e r a t i o n s r e q u i r e m e n t s t o s t i l l g e t P r o d u c t i o n f r o m t h e B i o l o g i c a l c r i t e r i a . C o n v e r s e l y , i f t h e s t r u c t u r e s a r e a l r e a d y t h e r e ( E n g i n e e r i n g ) , t h e n t h e y put c o n s t r a i n t s on t h e t y p e of P r o c e s s Figure 5. F a c i l i t y Design Science Interrelationships 51 and O p e r a t i o n s which can be c a r r i e d o u t , which i n t u r n l i m i t P r o d u c t i o n , based on B i o l o g i c a l s u i t a b i l i t y . A nother f e a t u r e i s the d i s t i n c t s e p a r a t i o n of the d i f f e r e n t d e s i g n s c i e n c e s . The a c t of b i o - e n g i n e e r i n g i n f a c t cannot o c c u r . One c a n n o t , f o r i n s t a n c e , o p t i m i z e the growth of f i s h from a c e r t a i n head of water. F i r s t one o p t i m i z e s the growth i n a c e r t a i n environment, then one p r o v i d e s enough f l o w to m a i n t a i n t h a t environment, then one c a l c u l a t e s a l t e r n a t i v e s t r u c t u r e s r e q u i r e d t o o b t a i n t h a t f l o w from a c e r t a i n head of water, then one o p t i m i z e s the a l t e r n a t i v e s based on c o s t . Each of the d e s i g n s c i e n c e s c o n s t r a i n s the o t h e r s but does not determine the o t h e r s . T h i s i s a v e r y i m p o r t a n t p o i n t . S i n c e a d j u s t m e n t s a r e always p o s s i b l e w i t h i n each of the s c i e n c e s , improvements can always be made. T h i s emphasizes the need f o r i t e r a t i o n i n d e s i g n - - g o i n g back and f o r t h and around and around a d e s i g n c o n c e p t , l o o k i n g at i t from the v i e w p o i n t of one s c i e n c e and then another and then another s t i l l . N o r m a l l y , s e v e r a l i t e r a t i o n s can be worked t h r o u g h b e f o r e improvements i n the d e s i g n become i n s i g n i f i c a n t . S e v e r a l a u t h o r s suggest s t e p - w i s e approaches t o f a c i l i t y d e s i g n ( T a b l e 1). These approaches a r e v e r y s i m i l a r t o one a n o t h e r , c o n t a i n i n g m a i n l y the f o l l o w i n g s t e p s : 1. An i n f o r m a t i o n g a t h e r i n g p e r i o d 2. L a y i n g out g e n e r a l l y what i s r e q u i r e d 3. D e c i d i n g e x a c t l y what w i l l be p r o v i d e d at t h i s f a c i l i t y , and 4. T u r n i n g t h a t f i n a l d e s i g n i n t o a r e a l i t y . A c t u a l l y , t h e s e s t e p s s h o u l d be c a r r i e d out s e p a r a t e l y ( i n sequence, or c o n c u r r e n t l y ) f o r each of the v i e w p o i n t s c i e n c e s , 52 T a b l e J_. Steps In F a c i l i t y D e s i g n Muther and H a l e s (1979) Fox (1978) O r i e n t a t i o n O v e r a l l P l a n D e t a i l e d P l a n s Implementat i o n F o l l o w Up E x p l o r a t o r y S t u d i e s T e c h n i c a l C r i t e r i a P r o j e c t D e s i g n C o n s t r u c t i o n O p e r a t i o n Mayo (1974) Jepson and T a y l o r (1981) Background B i o E n g i n e e r i n g C r i t e r i a F a c i l i t y D e s i g n F a c i l i t y Cost Hatchery Tour Develop C r i t e r i a D e sign Report P l a n s And S p e c i f i c a t i o n s O p e r a t i o n s Manual 53 making the d e s i g n p r o c e s s m u l t i - d i m e n s i o n a l as w e l l as i t e r a t i v e . The major c o n s i d e r a t i o n f o r each of the s t e p s a r e d i s c u s s e d i n the f o l l o w i n g s e c t i o n s . b. O r i e n t a t i o n The purpose of the proposed f a c i l i t y s h o u l d be c l e a r l y s t a t e d ; t h a t i s , whether the main f u n c t i o n i s r e s e a r c h , food p r o d u c t i o n , waste t r e a t m e n t , or some c o m b i n a t i o n . The r e l e v a n t e n v i r o n m e n t a l parameters s h o u l d be c o l l a t e d i n as g r e a t a d e t a i l as p o s s i b l e . The o p e r a t i o n a l c o n s t r a i n t s , d e t e r m i n i n g c a p i t a l and o p e r a t i o n a l c o s t i n p u t s , i n c l u d e a v a i l a b l e l a n d a r e a , water f l o w , equipment, power, machinery and l a b o u r . The p h y s i c a l c o n s t r a i n t s , d e t e r m i n i n g b i o l o g i c a l and pr o d u c t o u t p u t s , a r e water s o u r c e , q u a l i t y and t e m p e r a t u r e , and c l i m a t i c f a c t o r s and t h e i r s e a s o n a l i t y . There a r e a l s o the l i m i t a t i o n s s e t by r e g u l a t i o n s r e g a r d i n g water r i g h t s , d i s e a s e c o n t r o l and e f f l u e n t p o l l u t i o n , and by the economic c l i m a t e - -a v a i l a b l e m a rkets, t h e i r s i z e , type and s e a s o n a l i t y , and optimum ti m e s f o r a c q u i r i n g c o n s t r u c t i o n and o p e r a t i o n a l r e s o u r c e s such as m a t e r i a l s , equipment, feeds and manpower. 54 c. B i o l o g i c a l C r i t e r i a T h i s s e c t i o n l i s t s the response of the organism t o e n v i r o n m e n t a l parameters w i t h i n the expected range and l i s t s the means of a c h i e v i n g a p p r o p r i a t e ( o p t i m a l ) parameter v a l u e s t h r o u g h e n g i n e e r i n g d e s i g n . F i r s t , the b i o e n g i n e e r i n g r e q u i r e m e n t s of the f i s h a r e documented w i t h r e g a r d t o water q u a n t i t y and q u a l i t y ( s t o c k i n g d e n s i t i e s , t e m p e r a t u r e s , oxygen and m e t a b o l i t e c o n c e n t r a t i o n s , f e e d and b r e e d i n g r e q u i r e m e n t s , growth r a t e s and d i s e a s e v e c t o r s ) . D e t a i l e d b i o l o g i c a l r e q u i r e m e n t s and c h a r a c t e r i s t i c s f o r i m p o r t a n t N o r t h American f i s h e s can be found i n C a r l a n d e r (1969) and B e l l (1973). Water q u a l i t y c r i t e r i a a r e g i v e n i n E n v i r o n m e n t a l P r o t e c t i o n Agency (1972) and T h u r s t o n et a l . (1979) and, f o r s a l m o n i d s , i n Sigma (1983). Approaches t o c a l c u l a t i n g b i o - e n g i n e e r i n g r e q u i r e m e n t s f o r f i s h a r e w e l l p r e s e n t e d i n Westers (1981) or K l o n t z e t a l . (1978). Second, the p r e s e n t c u l t u r a l p r o c e s s e s a re o u t l i n e d , i n c l u d i n g a l t e r n a t i v e means of meeting or a p p r o x i m a t i n g the o p t i o n a l c o n d i t i o n s through v a r i o u s m e c h a n i c a l or d e s i g n m a n i p u l a t i o n s ( f l o w r a t e s , heat exchange or m i x i n g water s o u r c e s , a e r a t i o n , f i l t r a t i o n , n a t u r a l or a r t i f i c i a l f e e d f o r m u l a t i o n and p r e s e n t a t i o n , spawning inducement t h r o u g h pond l e v e l m a n i p u l a t i o n or s t r i p p i n g and a r t i f i c i a l i n c u b a t i o n , and s t e r i l i z a t i o n or d i s i n f e c t i o n of source or r e c i r c u l a t i n g w a t e r s ) . G e n e r a l r e f e r e n c e s f o r t h e s e p r o c e s s e s a r e Brown and G r a t z e k (1980), Huet (1972), Bardach et a l . (1972), K l o n t z e t a l . (1979) and Wheaton (1977). 55 T h i r d , any i n c o m p a t i b i l i t i e s between the r e q u i r e m e n t s f o r one b i o l o g i c a l system and a n o t h e r , from an e n g i n e e r e d environment s t a n d p o i n t , s h o u l d be c l a r i f i e d and e i t h e r r e s o l v e d or a compromising d e c i s i o n made. d. F i s h C u l t u r e O p e r a t i o n s As background t o d e t e r m i n i n g the a c t u a l p r o c e s s e s and t i m i n g of the f i n a l o p e r a t i o n , the b i o l o g i c a l c y c l e of the a n i m a l i s o u t l i n e d . I t i s i m p o r t a n t t o know the age of spawning and the a c c e p t a b l e foods f o r the growing s i z e s of f i s h , p a r t i c u l a r l y f o r f i s h w i t h l a r v a l s t a g e s . In p l a n n i n g the y e a r l y o p e r a t i o n , a s e a s o n a l o p e r a t i o n a l c y c l e must be worked o u t , i n c l u d i n g t i m i n g of spawning, pond t r a n s f e r s , f e e d changes and h a r v e s t s . A d a i l y o p e r a t i o n a l p l a n must a l s o be worked out f o r each stage i n the s e a s o n a l c y c l e , i n c l u d i n g any i n s p e c t i o n , f e e d i n g , t r e a t m e n t , t r a n s p o r t , h a n d l i n g , p r o c e s s i n g , or spawning. Plomp et a l . (1977) g i v e a l i s t of d e t a i l e d o p e r a t i o n s f o r t r o u t f a r m i n g and the time r e q u i r e d f o r t h e i r e x e c u t i o n . These p r o c e s s e s a r e taken i n t o c o n s i d e r a t i o n when the g e n e r a l l a y o u t of the f a c i l i t y i s b e i n g d e s i g n e d ( B u f f a , 1972), such t h a t p r o p e r v e h i c l e a c c e s s i s g i v e n t o a r e a s which r e q u i r e i t and subcomponents are a r r a n g e d such t h a t the time and motion i n moving between them i s used e f f i c i e n t l y (Buss and M i l l e r , 1971). Once i t i s d e t e r m i n e d what items (seed, f e e d , manpower, water, e t c . ) w i l l be moved from one p l a c e t o a n o t h e r , the 56 economy of the o p e r a t i o n s can be a i d e d by u t i l i z i n g a number of s p e c i a l i z e d m a t e r i a l s h a n d l i n g a i d s ( A p p l e , 1977) or by a r r a n g i n g the work s t a t i o n s t o m i n i m i z e the l o a d d i s t a n c e s m a t e r i a l s a r e moved. Methods f o r the l a t t e r range from the s i m p l i f i e d , c u t - o u t t e c h n i q u e of Muther (1973) t o s o p h i s t i c a t e d , computer a i d e d d e s i g n (Tompkins and Moore, 1978). In a d d i t i o n t o w o r k i ng out the o p e r a t i o n p r o c e s e s s i n terms of t a s k s i n v o l v e d and t h e i r t i m i n g , as above, the o v e r a l i n p u t s of the v a r i o u s m a t e r i a l s , l a b o u r and equipment and t h e i r s c h e d u l i n g are r e l a t e d on an economic s c a l e t o the o u t p u t s and s c h e d u l i n g of p r o d u c t . There s h o u l d a l s o be a mass ba l a n c e w i t h r e g a r d t o f e e d - i n v e r s u s f i s h - o u t a t each food p a r t i c l e s i z e , s i n c e excess food of a p a r t i c l u l a r k i n d w i l l not s t o r e i n t a c t f o r many months, w a i t i n g f o r the new c r o p of f i n g e r l i n g s t o r e a c h the proper s i z e . There a r e many ways of s c h e d u l i n g i n p u t s and o u t p u t s , u s i n g t a b l e s and c h a r t s c o n s t r u c t e d from p r e v i o u s e x p e r i e n c e w i t h f i s h of the same k i n d ( B u t t e r b a u g h and W i l l o u g h b y , 1967) or by s i m u l a t i n g the growth of the organisms and comparing v a r i o u s management s t r a t e g i e s w i t h the s i m u l a t i o n o utput (Johnson, 1974). e. Economic F a c t o r s The most im p o r t a n t a s p e c t of a d e s i g n study i s the d e t e r m i n a t i o n of whether the v a l u e of the o u t p u t s i s g r e a t e r than the v a l u e of the i n p u t s , on a d o l l a r t o d o l l a r b a s i s ( P l a n n i n g Branch, 1976). O f t e n t h i s study i s done b e f o r e the 57 b i o l o g i c a l f e a s i b i l i t y i s d e f i n i t e l y d e t e r m i n e d s i n c e t h e r e i s no p o i n t i n c o n t i n u i n g w i t h b i o l o g i c a l f e a s i b i l i t y s t u d i e s i f t h e r e i s no chance of economic s u c c e s s no m atter how p r o d u c t i v e the system may be (Gates et a l . , 1980). There are a g r e a t number of methods of a n a l y s i s used t o p r e d i c t economic v i a b i l i t y . Some of these a r e o u t l i n e d below (from Shang, 1981; F r a l i k , 1980): i ) average r a t e of r e t u r n : the annual r a t i o of p r o f i t t o investment i i ) c o s t of p r o d u c t : t o t a l c o s t d i v i d e d by number of p i e c e s produced. i i i ) f i n a n c i a l a n a l y s i s : revenue (income minus c a p i t a l and o p e r a t i o n s c o s t s ) over p r o j e c t l i f e . i v ) h u r d l e r a t e : r e q u i r e d r a t e of r e t u r n f o r a c c e p t a n c e by i n v e s t o r . v) income st a t e m e n t : s i m p l e income minus c o s t s . v i ) i n t e r n a l r a t e of r e t u r n : d i s c o u n t r a t e t h a t equates p r e s e n t v a l u e of cash i n f l o w s t o o u t f l o w s . v i i ) m a r g i n a l p h y s i c a l p r o d u c t : change i n o u t p u t due t o u n i t change i n i n p u t v i i i ) net c ash f l o w : movement of money i n t o , out of and w i t h i n p r o j e c t . i x ) net p r e s e n t v a l u e (NPV): d i s c o u n t s p r e s e n t v a l u e of f u t u r e c a s h f l o w s a t i n v e s t o r ' s r a t e of r e t u r n . x) pay back p e r i o d : time r e q u i r e d t o pay o f f i n i t i a l i n v e s t m e n t . x i ) s e n s i t i v i t y a n a l y s i s : broader spectrum of m a r g i n a l 58 p r o d u c t type a n a l y s i s , x i i ) shadow p r i c i n g : m a r g i n a l p r e s e n t v a l u e , or the h u r d l e r a t e on the NPV method. These methods have one or both of two aims i n mind - t o p r o v i d e an index of p o t e n t i a l v i a b i l i t y or a p r e d i c t o r of f u t u r e v i a b i l i t y . I n d i c e s may be f o r s i m p l e summary of c o s t i n f o r m a t i o n (income s t a t e m e n t , c o s t of p r o d u c t ) or f o r comparison of d i f f e r e n t t y p e s of investment w i t h one another ( r a t e s of r e t u r n , payback p e r i o d ) . P r e d i c t o r s a r e d e s i g n e d t o e i t h e r e q u a l i z e the e x p e c t e d e f f e c t s of time (NPV, shadow p r i c i n g ) or t o t r y t o guess at (and p r e p a r e f o r ) the f u t u r e ( f i n a n c i a l a n a l y s i s , s e n s i t i v i t y a n a l y s e s ) . At the base l e v e l however, the most i m p o r t a n t c o n s i d e r a t i o n i s p r o f i t - can a p r o j e c t make more money than i t c o s t s - as e s t i m a t e d by the income s t a t e m e n t . The f u t u r e , i n f a c t , cannot be p r e d i c t e d , nor are e l a b o r a t e comparisons between t y p e s of i n v e s t m e n t s of much v a l u e when o n l y one or two a l t e r n a t i v e s a r e a v a i l a b l e or a p p r o p r i a t e . For t h e s e reasons the income statement f o r a t y p i c a l year of o p e r a t i o n i s p r o b a b l y the most u s e f u l c r i t e r i o n i n d e t e r m i n i n g economic v i a b i l i t y . I f i t i s p o s s i b l e t o s u r v i v e and make a p r o f i t the f i r s t y e a r and changes from the f i r s t year a r e e x p e c t e d t o be r e l a t i v e ( t h a t i s , as c o s t s go up, so w i l l p r i c e s ) , then the e n t e r p r i s e s h o u l d be v i a b l e as a b u s i n e s s . T h i s does not n e c e s s a r i l y mean i t would be a good i n v e s t m e n t , s i n c e the money i n v e s t e d might y i e l d a h i g h e r r a t e of r e t u r n i f used i n a n o t h e r f a s h i o n . 59 The f i r s t c o n s i d e r a t i o n i n the income statement i s c a p i t a l c o s t , that i s , the cost of p l a n n i n g , s u r v e y i n g , c o n s t r u c t i n g and implementing the system. T h i s i n c l u d e s a l l expenses from the moment of conception to the time when the system i s op e r a t i n g under f u l l o p e r a t i o n a l c a p a c i t y . G e n e r a l l y one or both of two ways of e s t i m a t i n g t h i s cost are employed. The f i r s t i s assessment by precedence. T h i s i n v o l v e s l o o k i n g through records at the c o s t s encountered i n previous implementation of systems s i m i l a r to the one p r e s e n t l y c o n s i d e r e d . These c o s t s ( i . e . $/volume of raceway, $/area of f l o o r space f o r b u i l d i n g s ) are a d j u s t e d f o r i n f l a t i o n , l o c a l labour and m a t e r i a l cost to a r r i v e at an es t i m a t e . The second method i s assessment by survey e n g i n e e r i n g . T h i s kind of assessment can only be done a f t e r the complete a r c h i t e c t u r a l and c o n s t r u c t i o n plans have been completed. The plans are given to a survey engineer who goes through them, i t e m i z i n g every m a t e r i a l and c o n s t r u c t i o n procedure and a r r i v e s at f i g u r e s , f o r example, on e x a c t l y how many n a i l s are r e q u i r e d , how many man-hours are r e q u i r e d to d r i v e them i n , and how much the t o t a l o p e r a t i o n , m a t e r i a l and labour, w i l l c o s t at c u r r e n t p r i c e s and wages. T h i s d e t a i l e d c a l c u l a t i o n i s p a r t i c u l a r l y a p p r o p r i a t e fo r budgeting o p e r a t i o n s which d e v i a t e d r a s t i c a l l y from pre v i o u s designs, and f o r which there are no v a l i d precedents. The second c o n s i d e r a t i o n i n economic v i a b i l i t y i s the comparison of the d a i l y , weekly or monthly product outputs with the o p e r a t i n g c o s t s over the same p e r i o d s . The outputs are subje c t to the b i o l o g i c a l c o n s t r a i n t s of growth and 60 s e a s o n a l i t y . The o p e r a t i n g c o s t s are d i r e c t l y r e l a t e d to the o p e r a t i o n p r o c e s s . T h i s i n c l u d e s l a b o u r (both management and employee), f e e d , machinery and equipment o p e r a t i o n and maintenance, s t o r a g e of f e e d and p r o d u c t , p r o c e s s i n g , s e c u r i t y and i n t e r e s t on l o a n s . Some o p e r a t i n g c o s t s are f i x e d ( b u i l d i n g overhead, i n t e r e s t , s e c u r i t y ) and some w i l l v a r y a c c o r d i n g t o the phase of the o p e r a t i o n ( l a b o u r , f e e d , t r a n s p o r t ) , t h i s l e a d s t o a n other a s p e c t of c o s t , t h a t of s c a l e up. The system s h o u l d be d e s i g n e d f o r maximum u t i l i z a t i o n of a v a i l a b l e r e s o u r c e s w i t h c o n t i n g e n c y f o r t e c h n o l o g i c a l developments which would i n c r e a s e p r o d u c t i v i t y . When the f a c i l i t y i s c o n s t r u c t e d , o n l y one phase of the f i n a l , p o t e n t i a l , o v e r a l l o p e r a t i o n i s b u i l t , the o t h e r modules remain as p l a n s u n t i l the system r e l i a b i l i t y and f e a s i b i l i t y of s c a l e up a r e p roven. Another i m p o r t a n t f a c t o r t o c o n s i d e r under the c o s t s of r u n n i n g a b i o l o g i c a l p r o d u c t i o n f a c i l i t y i s p r o v i s i o n f o r r e s e a r c h and development. I t i s always p o s s i b l e t o improve the q u a n t i t y or q u a l i t y of output once the p l a n t i s i n o p e r a t i o n and i t s p a r t i c u l a r dynamic c h a r a c t e r i s t i c s can be s t u d i e d . The f i r s t d e s i g n i s always on the c o n s e r v a t i v e s i d e t o ensure r e l i a b i l i t y , but once o p e r a t i o n commences, a c e r t a i n amount of m a n i p u l a t i o n of parameters may prove b e n e f i c i a l i n c u t t i n g c o s t s per u n i t o u t p u t . T h i s method of e x p e r i m e n t a t i o n i n v o l v e s keeping s p e c i f i c s t a t i s t i c a l l y r e l e v a n t d a t a on the e f f e c t s of r e l a t i v e l y s m a l l p e r t u r b a t i o n s imposed on the system. M o n i t o r i n g f i s h h e a l t h and growth c o n d i t i o n a r e v e r y i m p o r t a n t d u r i n g such m a n i p u l a t i o n s near the i n t e r f a c e of . s u i t a b l e v e r s u s 61 s t r e s s i n d u c i n g environments (Wedemeyer et a l . , 1976). An economic f a c t o r on a more ma c r o s c o p i c s c a l e which i s v i t a l t o determine b e f o r e c o n s t r u c t i o n b e g i n s C t h a t i s , as a p a r t of the d e s i g n s t u d y ) i s the n a t u r e of a v a i l a b l e m a rkets, t h e i r s i z e , l o c a t i o n , p r o d uct p r e f e r e n c e , a c c e p t a b l e p r i c e and r e l i a b i l i t y . T h i s may be done on a s u p e r f i c i a l b a s i s , u s u a l l y as an e x t r a p o l a t i o n of p r e s e n t s u p p l y and demand c h a r a c t e r i s t i c s and s u c c e s s of p r e s e n t o p e r a t o r s , or may i n v o l v e a complete market survey of w h o l e s a l e and r e t a i l o u t l e t s and consumer o p i n i o n . C o n t r o l of the market v a r i a b l e s ( i . e . not o v e r l o a d i n g the market at c e r t a i n t i m e s of the year and u n d e r s u p p l y i n g a t o t h e r t i m e s ) t o ensure a r e l i a b l e product-consumer r e l a t i o n s h i p , s h o u l d be an i n t e g r a l p a r t of the d e s i g n p r o c e s s ( i . e . p r o v i s i o n of c o l d s t o r a g e t o s p r e a d out p r o d u c t a v a i l a b i l i t y t i m e ) . C. P r o c e s s Requirements a. T e c h n i c a l S u i t a b i l i t y T h i s s e c t i o n d e a l s i n somewhat more d e t a i l w i t h the b i o -e n g i n e e r i n g p o r t i o n of the p r e v i o u s d e s i g n p r o c e s s o u t l i n e , due t o i t s c r i t i c a l e f f e c t on the v i a b i l i t y of the o v e r a l l d e s i g n . B i o - e n g i n e e r i n g , i n t h i s c a s e , r e f e r s t o the p r e c i s e matching of the b i o l o g i c a l e n t i t y t o be c u l t u r e d w i t h the p h y s i c a l environment i n which i t must l i v e . Two b a s i c approaches may be t a k e n t o t h i s end. The f i r s t i s t o s t a r t w i t h a c u l t u r e 62 environment which has been p r e d e t e r m i n e d — d u e t o water s u p p l y , l o c a t i o n or c l i m a t i c c o n s t r a i n t s , f o r e x a m p l e — a n d then s e l e c t a s p e c i e s of organism f o r which the environment i s s u i t a b l e and w hich a l s o has some economic v a l u e . The second approach i s t o s e l e c t a d e s i r a b l e s p e c i e s t o be c u l t u r e d and then e n g i n e e r the environment such t h a t i t matches the b a s i c ( o p t i m a l ) r e q u i r e m e n t s of the s p e c i e s . C i v i c a q u a r i a a r e e n g i n e e r i n g m a s t e r p i e c e s a t p r o v i d i n g a g r e a t v a r i e t y of i d e a l environments f o r f i s h w i t h v e r y d i f f e r e n t b i o l o g i c a l r e q u i r e m e n t s . In most c a s e s , both approaches occur r e l a t i v e l y s i m u l t a n e o u s l y . That i s , f o r example, the g r e a t e s t demand f o r m i l k f i s h , and t h e r e f o r e m o t i v a t i o n f o r m i l k f i s h c u l t u r e , comes from c o a s t a l a r e a s of t r o p i c a l c o u n t r i e s , where m i l k f i s h i s most e f f i c i e n t l y c u l t u r e d . Whichever approach i s t a k e n , the f i r s t s t age i s t o d e t e r m i n e , i n g r e a t d e t a i l , the b a s i c r e q u i r e m e n t s (and t h e i r c u l t u r a l v a l u e s ) f o r the p o t e n t i a l c u l t u r e d organisms. K l o n t z et a l . (1979) have c o m p i l e d a l i s t ( T a b le 2) of the more im p o r t a n t f a c t o r s a f f e c t i n g the p r o d u c t i v i t y of t r o u t and salmon. T h i s 51 item l i s t o n l y r e f e r s t o parameters which are a d j u s t a b l e a f t e r most of the c o n c e p t u a l d e s i g n d e c i s i o n s have been made. Many of these items f a l l under the u m b r e l l a c a l l e d "good f i s h c u l t u r e t e c h n i q u e s " , "proper c a r e " , or the "good house k e e p i n g " of S t a u f f e r (1973). That i s , t h e r e i s a r i g h t way and a wrong way t o do most t h i n g s and any good f i s h c u l t u r i s t w i l l f o l l o w the r i g h t way. For example, by p r o p e r f r e q u e n t pond c l e a n i n g t o reduce s e t t l e a b l e s o l i d s , BOD d e c r e a s e s , a v a i l a b l e 63 Table 2 . from K l o n t z e t a l . , Factors affecting the productiv A. Fish Associated 1. Ammonia-nitrogen 2. Behavior 3. Nutritional requirements 4. Environmental requirements a. physical b. chemical 5. Product definition B. Water Associated 1. Dissolved oxygen 2. Nitrite-nitrogen 3. Alkalinity 4. pH 5. Inflow in gpm of cfs 6. Suspended solids 7. Settleable solids 8. Temperature (constant or variable) 9. Carrying Capacity 10. Agricultural contaminants 11. Industrial contaminants C. Container Associated 1. Water volume 2. Water velocity 3. Composition 4. Water flow pattern D. Nutrition Associated 1. Feeding rate 2. Feed efficiency 3. Feed style E. Management Associated 1. Fish sampling techniques 2. Feeding frequency 3. Feeding techniques 4. Record keeping 979. ; of trout and salmon raising facilities. 7. Infectious disease history 8. Length-weight relationship 9. Cannibalism 10. Oxygen uptake 11. Oxygen demand 12. Fecal solids 13. CO2 12. Municipal contaminants 13. Natural contaminants a. N2 b. CO2 c. H2S d. Fe 14. Utilization 15. Salinity 16. Hardness (Ca+ + ) 17. B.O.D. 18. Viscosity 5. Water replacement time 6. Outfall design 7. Shape 4. Nutritional quality a. proximate analysis b. metabolizable energy 5. Feed Storage 5. Pond cleaning 6. Fish size grading techniques 7. Management programming 8. Management objectives 64 oxygen i n c r e a s e s and c a r r y i n g c a p a c i t y i n c r e a s e s . Another u m b r e l l a encompassing many of the s e f a c t o r s , and working i n the same i n t e r a c t i v e and i n t e r d e p e n d e n t way i s water q u a l i t y . Many a g e n c i e s ( E n v i r o n m e n t a l P r o t e c t i o n Agency, 1972, among o t h e r s ) have p u b l i s h e d a c c e p t a b l e v a l u e ranges (maxima, minima or both) f o r a wide v a r i e t y of p h y s i c a l and c h e m i c a l p a r a m e t e r s . U n a c c e p t a b l e water s o u r c e s a r e u s u a l l y e i t h e r p o l l u t e d ( n u t r i e n t l o a d e d from human a c t i v i t y ) , n a t u r a l l y e u t r o p h i c or c o n t a m i n a t e d ( c o n t a i n i n g u n a c c e p t a b l e l o a d s of t o x i c s u b s t a n c e s , whether n a t u r a l l y o c c u r r i n g or from human s o u r c e s ) . A c c e p t a b l e s o u r c e s may be d i r e c t l y s u i t a b l e or e a s i l y a l t e r e d t o a s u i t a b l e c o n d i t i o n , f o r i n s t a n c e by a e r a t i o n or f i l t r a t i o n . Once a c h e m i c a l l y s u i t a b l e source of water has been found (or e n g i n e e r e d ) , we must c o n s i d e r the e f f e c t t h a t the f i s h c u l t u r e has i n d e g r a d i n g the water q u a l i t y . Assuming good hou s e k e e p i n g , the main c o n c e r n s a re the uptake of oxygen and the c r e a t i o n of n i t r o g e n o u s wastes (McLean, 1979). The l a t t e r p r o c e s s tends t o approach c r i t i c a l l e v e l s a t about one t h i r d the r a t e of the former (Haywood et a l . , 1980). The second s t e p i n b i o - e n g i n e e r i n g , once a c o n c e p t u a l p l a n has been worked out which i s t e c h n i c a l l y v i a b l e and appears t o be s u i t a b l e , i s t o q u a n t i t a t i v e l y match i n p u t s and o u t p u t s t o the system, such t h a t c o s t and revenue e s t i m a t i o n may be done. The g o a l here i s t o det e r m i n e how much water, space, f o o d , l a b o u r and energy must go i n t o p r o d u c i n g a g i v e n q u a n t i t y of m a r k e t a b l e p r o d u c t . The most common method f o r e s t i m a t i n g 65 i n p u t s and o u t p u t s i s t o f i n d a v i r t u a l l y i d e n t i c a l system which i s o p e r a t i n g s u c c e s s f u l l y and t o p a t t e r n the new system a f t e r i t . T h i s approach o b v i o u s l y l i m i t s i n o v a t i o n i n d e s i g n t o r e l a t i v e l y s m a l l changes. More p r e c i s e and a d a p t a b l e q u a n t i t a t i v e methods have been d e v e l o p e d f o r some t y p e s of a q u a c u l t u r e , most p a r t i c u l a r l y f o r pond/raceway c u l t u r e of salmon and t r o u t . Q u a n t i f i c a t i o n of the concept f o l l o w s an almost s t e p - l i k e sequence. P i p e r et a l . (1982) l i s t s the sequence of items t o be d e t e r m i n e d f o r each d e s i g n : 1. Temperature of water 2. Major event t i m i n g (egg t a k e , p o n d i n g , h a r v e s t , e t c ) 3. Weight of each f i s h 4. Numbers of f i s h ( t i m e s weight g i v e s biomass) 5. Flow r e q u i r e m e n t s ( f o r plumbing d e s i g n ) 6. Space r e q u i r e m e n t s ( f o r c o n t a i n e r d e s i g n ) . P i p e r s t a r t s w i t h temperature because i t i s most o f t e n the major l i m i t i n g d r i v i n g v a r i a b l e f o r f i s h growth, g i v e n t h a t the f i s h c u l t u r e t e c h n i q u e s used are optimum. The p r o c e s s i s not i n s t r i c t sequence, however, s i n c e a l t h o u g h f l o w r e q u i r e m e n t s are based on the number and weight of f i s h r a i s e d ( a t a c e r t a i n t e m p e r a t u r e ) a l i m i t e d water s u p p l y w i l l d e t e r m i n e the maximum number or s i z e of f i s h t h a t can be r a i s e d . The water temperature p r o j e c t e d can be o b t a i n e d from a c t u a l r e c o r d s of the s o u r c e or from i n f o r m e d guesses. Event t i m i n g s are o f t e n r e l a t e d t o the l i f e h i s t o r y of the f i s h , such as n a t u r a l spawning t i m i n g , or t o e n v i r o n m e n t a l c o n s t r a i n t s t o f i s h 66 c u l t u r e such as f r e e z e - u p . The weight of the f i s h over time i s p r o j e c t e d u s i n g l o c a l p r e c e d e n t s or a growth model (see M o d e l l i n g A q u a t i c P r o d u c t i o n f o r d i s c u s s i o n ) . Flow and space r e q u i r m e n t s a l s o f o l l o w p r e c e d e n t s or a r e m o d e l l e d (see next s e c t i o n s ) . These items p r o v i d e o n l y the b a r e s t bones t o the f a c i l i t y d e s i g n . To them s h o u l d be added: 7. O p e r a t i o n s I n p u t s , such as manpower, f i s h f o o d , power, f u e l , c h e m i c a l s and o t h e r s u p p l i e s , f o l l o w e d by the s t r u c t u r e s r e q u i r e d t o p r o v i d e those i t e m s . b. Flow Requirements Water f l o w r e q u i r e m e n t s f o r s a l m o n i d s a r e n o r m a l l y c o n s i d e r e d as a f u n c t i o n of oxygen a v a i l a b i l i t y v e r s u s m e t a b o l i c oxygen uptake r a t e . Oxygen a v a i l a b l e i s the d i f f e r e n c e between the i n f l o w and o u t f l o w c o n c e n t r a t i o n s times the f l o w . T h i s i s used i n a l l the e q u a t i o n s below t o c o n v e r t m e t a b o l i c r a t e t o pounds of f i s h which can be put i n a pond. W i l l o u g h b y (1968) c o n s i d e r s oxygen uptake as a d i r e c t f u n c t i o n of the amount of food dumped i n t o the pond, s i n c e t h i s ' f u e l ' i s e i t h e r m e t a b o l i z e d by the f i s h or by pond b a c t e r i a (BOD): Wt = (Oi-Oo)*5.45*Qi*L (1) Cf*DL*300 where: Wt = t o t a l weight of f i s h which can be r e a r e d i n the pond; Oi = i n f l o w i n g oxygen (ppm); Oo = o u t f l o w i n g oxygen (ppm); Qi = f l o w through pond (gpm); Cf = f e e d c o n c e n t r a t i o n f a c t o r ( f e e d : f i s h ) ; L = f i s h l e n g t h ( i n c h e s ) ; DL = e x p e c t e d 67 d a i l y l e n g t h i n c r e a s e ( i n c h e s ) ; and 5.45, 300 = u n i t c o n v e r s i o n f a c t o r s . To use t h i s e q u a t i o n , one must be a b l e t o p r e d i c t both the ex p e c t e d d a i l y growth and the f e e d c o n v e r s i o n e f f i c i e n c y . I t s h o u l d be noted t h a t a l t h o u g h i t i s d e s i r a b l e t o quote e q u a t i o n s d e v e l o p e d by o t h e r a u t h o r s v e r b a t i m , t h i s can o f t e n l e a d t o i n c o n s i s t e n c i e s i n s t y l e and c o n f u s i o n i n the r e p o r t i n g of v a r i a b l e s and c o n s t a n t s . The f o l l o w i n g c o n v e n t i o n s w i l l be used h e r e : m u l t i p l i c a t i o n w i l l be r e p r e s e n t e d by an a s t e r i s k (*); e x p o n e n t i a t i o n w i l l be r e p r e s e n t e d by a s u p e r s c r i p t ( i f a s i m p l e number), by w r i t i n g on a l i n e above or by a double a s t e r i s k (**) w i t h the exponent f o l l o w i n g i n p a r e n t h e s e s ) ; n a t u r a l l o g a r i t h m s by the symbols Ln or LOG ( i n BASIC computer programs); n a t u r a l a n t i - l o g s by the l e t t e r 'e' w i t h a s u p e r s c r i p t , or exp or EXP (BASIC) w i t h the o b j e c t f o l l o w i n g i n p a r e n t h e s i s . Most of the v a r i a b l e names a r e the same as the o r i g i n a l forms, except when n o n - c o n v e n t i o n a l symbols were used i n the sour c e p u b l i c a t i o n s or where the same v a r i a b l e has a l r e a d y been d e f i n e d w i t h a n o t h e r symbol. The meaning of v a r i a b l e names a r e d e f i n e d i n the t e x t . M e t a b o l i c oxygen uptake r a t e i s a f u n c t i o n of more than j u s t f e e d i n g r a t e . The most i m p o r t a n t o t h e r f a c t o r s a r e water temperature and f i s h s i z e . E l l i o t (1969) r e l a t e s the a c c e p t a b l e weight of f i s h which can be l o a d e d i n t o a pond as a f u n c t i o n of m e t a b o l i c r a t e s t h u s : Wt = (Oi-Oo)*Qi (2) RO where: m e t a b o l i c r a t e , RO, i s d e t e r m i n e d f o r f i s h of a c e r t a i n 68 s i z e a t a c e r t a i n temperature by a group of l i n e a r e q u a t i o n s d e r i v e d from e m p i r i c a l d a t a f o r chinook salmon f i n g e r l i n g s . L i a o (1971) t a k e s the same approach but uses some non l i n e a r f u n c t i o n s t o r e l a t e m e t a b o l i c r a t e t o temperature and f i s h s i z e . Wt = (Oi-Oo)*Qi*1.2 (3) Kst*TF *W where: TF = temperature(°F); W = f i s h w e i g h t ( l b ) ; K s t = s p e c i e s and temperature dependent c o n s t a n t s ; 1.2 = u n i t c o n v e r s i o n f a c t o r . F i n a l l y we come t o an e q u a t i o n which r e l a t e s m e t a b o l i c r a t e t o a l l t h r e e of i t s main d r i v i n g v a r i a b l e s : f e e d i n g r a t e , t emperature and f i s h s i z e . T h i s comes from McLean (1979): Wt = Oi-Oo*Qi*60 (4) (a-b*FR) (b*FR-a) (d*T) (g*T) 1.35*20 *Wt *c*e +f*e *FMAX*FR where: Wt = f i s h w e i g h t ( g r a m s ) ; T = temperature(°C); 60 = u n i t c o n v e r s i o n ; FMAX = t h e o r e t i c a l maximum r a t i o n ; FR = f r a c t i o n of maximum r a t i o n f e d ; e =2.718. 20; a, b, c, d, f , g = n u m e r i c a l c o n s t a n t s ; 1.35 = c o r r e c t i o n f a c t o r from average t o d a i l y h i g h m e t a b o l i c r a t e . (For an e x p l a n a t i o n of FR and FMAX, see be l o w ) . T h i s e q u a t i o n reaches the g o a l of the b i o - e n g i n e e r , i . e . t o have a m a t h e m a t i c a l f i s h which responds t o v a r y i n g l e v e l s of the d r i v i n g e n v i r o n m e n t a l v a r i a b l e s much as a l i v i n g f i s h would do. I t a l s o e l i m i n a t e s from i n p u t 'very s i t e s p e c i f i c r e q u i r e m e n t s , such as e x p e c t e d c o n v e r s i o n and growth r a t e s . The recommended f r a c t i o n of maximum r a t i o n t o be f e d can be used as a s p e c i e s or l o c a t i o n s p e c i f i c c o r r e c t i o n f a c t o r . 69 c. Space Requirements R e a r i n g space r e q u i r e m e n t s can be approached i n two b a s i c ways. The f i r s t i s based on the b e h a v i o r a l or t e r r i t o r i a l t o l e r a n c e s of the f i s h -- t h a t i s , how much room does the f i s h l i k e t o have. T h i s c o u l d become a v e r y complex i s s u e but i t seems t h a t , so f a r , o n l y r e l a t i v e l y s i m p l e r e l a t i o n s h i p s between the s i z e of f i s h and the a c c e p t a b l e l o a d i n g d e n s i t y ( i n u n i t s of f i s h weight t o u n i t s of water volume) have been i d e n t i f i e d . P i p e r ' s (1972) method uses a d e n s i t y f a c t o r (D, i n l b s of f i s h / c u b i c f o o t of w a t e r / i n c h of f i s h l e n g t h ) which i s a c t u a l l y the s l o p e of the l i n e r e l a t i n g f i s h s i z e (L, i n i n c h e s ) t o l o a d i n g d e n s i t y . L o a d i n g d e n s i t y t i m e s the volume (V) g i v e s the t o t a l f i s h weight which can be r e a r e d ( w t ) : Wt = D*V*-L (5) P i p e r s u g g e s t s t h a t D = .5 i s a p p r o p r i a t e f o r t r o u t . Burrows and Combs (1968) p r e s e n t a s i m i l a r r e l a t i o n s h i p w i t h s l i g h t l y d e c r e a s i n g s l o p e ( i n s t a n z a s ) on the s i z e v e r s u s l o a d i n g d e n s i t y graph. The second approach t o space requirement c a l c u l a t i o n s i s , as w i t h f l o w r e q u i r e m e n t s , t o c r e a t e a r e l a t i o n s h i p between space and the m e t a b o l i c d r i v i n g v a r i a b l e s . T y p i c a l of t h i s genre i s Wester's (1981) e q u a t i o n : Wt = Wf*R*V (6) 8 where: Wf = f l o w l o a d i n g ( l b s/gpm); R = water exchanges/hour; V = Volume ( c u b i c f e e t ) ; and 8 = u n i t c o n v e r s i o n . One must know (or p r e v i o u s l y c a l c u l a t e ) the f l o w l o a d i n g 70 r a t e and s e t the number of exchanges per hour t o use t h i s method. Water changes per hour a r e a very p o p u l a r concept among f i s h c u l t u r i s t s but they a r e r e a l l y o n l y a way of r e l a t i n g a c c e p t a b l e f l o w s t o a c c e p t a b l e s t o c k i n g d e n s i t i e s and p r o v i d e no added i n s i g h t i n t o e i t h e r c r i t e r i a . I t i s l i k e l y t h a t space r e q u i r e m e n t , from the f i s h ' s needs p o i n t of view, may be r e l a t e d t o pond water v e l o c i t i e s as w e l l as f i s h s i z e , but no p u b l i s h e d i n f o r m a t i o n i s a v a i l a b l e on t h i s s u b j e c t i n r e l a t i o n t o d e s i g n . d. Feed Requirements The s i m p l e s t approach t o o v e r a l l s i z i n g of f e e d r e q u i r e m e n t s i s t o assume a c e r t a i n f e e d c o n v e r s i o n f a c t o r (between 1:1 and 2:1; feed t o f i s h ) , based on n e i g h b o u r i n g precedences and c a l c u l a t e f e e d r e q u i r e d f o r the t a r g e t number and s i z e of f i s h . T h i s means t h a t both the o v e r a l l s u r v i v a l r a t e s and growth r a t e s from s t o c k i n g t o h a r v e s t must be known. These a r e d e a l t w i t h i n the m o d e l l i n g s e c t i o n s . D a i l y f e e d i n g amounts a r e most o f t e n read o f f from t a b l e s , such as t h a t i n Freeman et a l . (1967), d i s t r i b u t e d by the f e e d m a n u f a c t u r e r s . B u t t e r b a u g h and W i l l o u g h b y (1967) must e s t i m a t e both f e e d c o n v e r s i o n and d a i l y i n c r e m e n t a l growth t o c a l c u l a t e d a i l y f e e d r a t e : F% = 3*Cf*DL*100 (7) L where: F% = p e r c e n t body weight t o f e e d d a i l y ; Cf = f e e d c o n v e r s i o n f a c t o r ; DL = d a i l y l e n g t h i n c r e a s e ( i n c h e s ) ; and L = 71 l e n g t h of f i s h ( i n c h e s ) . The numerator was then c o n s o l i d a t e d i n t o one number, c a l l e d the h a t c h e r y c o n s t a n t (HC), but t h i s adds no more i n f o r m a t i o n and masks the s o u r c e s of the d r i v i n g v a r i a b l e s . S t a u f f e r (1973), based on v a r i o u s works by B r e t t (1971), d e v e l o p e d e m p i r i c a l formulae f o r maintenance and maximum r a t i o n s . FMAINT = 0.1844*10**(0.0504*T**(~0.2)) (8) FMAX = W t * * ( l / 3 ) * ( 1 0 . 7 3 * L n ( T F ) - 3 7 . 7 1 ) (9) where: FMAINT = maintenance r a t i o n ; FMAX = maximum a s s i m i l a b l e r a t i o n ; T = t e m p e r a t u r e ( c e l s i u s ) ; TF = t e m p e r a t u r e ( f a h r e n h e i t ) ; Wt = f i s h w e i g h t ( g r a m s ) ; R a t i o n s are e x p r e s s e d i n per cent body weight t o be f e d per day. A c o r r e c t i o n f a c t o r , FR ( f r a c t i o n of maximum r a t i o n a c t u a l l y fed) can be used t o modify the t h e o r e t i c a l c o n d i t i o n s t o a c t u a l p r a c t i c e f o r a p a r t i c u l a r s p e c i e s or l o c a t i o n . S i n c e FMAX c l o s e l y a p p r o x i m a t e s the v a l u e s on the f e e d t a b l e s f o r Oregon M o i s t P e l l e t Feeds produced by Moore C l a r k e L t d . of Oregon, the FR v a l u e i s the r e c o r d e d f r a c t i o n of the OMP c h a r t a c t u a l l y f e d , based on how much food the f i s h w i l l t a k e . The a c t u a l amount of food f e d , t h e n , i s : DF = FR*FMAX* *(Wt)*N (10) where: the d a i l y food f e d (DF, i n k i l o g r a m s ) i s the product of the f r a c t i o n (FR) of the maximum r a t i o n (FMAX, i n %body weight per day) t i m e s the average i n d i v i d u a l f i s h s i z e (Wt, i n grams) t i m e s the number of f i s h f e d (N, i n t h o u s a n d s ) . Summing up a l l the d a i l y f e e d r e q u i r e m e n t s g i v e s the t o t a l amount of food 72 r e q u i r e d . T h i s l a t t e r approach has two major advantages over the o t h e r s . F i r s t , f o r p r e d i c t i o n p u r p o s e s , i t i s based o n l y on two b a s i c d r i v i n g v a r i a b l e s of f i s h m e tabolism--temperature and f i s h weight (a much b e t t e r e s t i m a t o r of biomass than l e n g t h ) . Second, f o r e v a l u a t i o n p u r p o s e s , o n l y one, e a s i l y r e p o r t e d v a r i a b l e (FR) can be used t o compare performance of d i f f e r e n t s p e c i e s , l o c a t i o n s , foods or f e e d i n g p r a c t i c e s . D. E n c l o s u r e s a. I n t r o d u c t i o n In the d e s i g n of a q u a c u l t u r a l systems, the co n c e p t s of i n t e n s i v e v e r s u s e x t e n s i v e management grade i n t o one another depending on the degree of c o n t r o l e x e r t e d over the c u l t u r e d organism. U s u a l l y , t o be c o n s i d e r e d c u l t i v a t e d , an organism must be ' e n c l o s e d ' at some p a r t of i t s l i f e h i s t o r y o t h e r than o n l y i n the a c t of h a r v e s t . T h i s e n c l o s u r e may be v e r y l a r g e as i n the case of r e s e r v o i r s , l a k e s or f j o r d s , or may be as s m a l l as a q u a r i a or j a r s . As s m a l l e r growout e n c l o s u r e s are used, h a r v e s t becomes e a s i e r , such t h a t a t some p o i n t the a n i m a l s no l o n g e r need t o be f i s h e d out w i t h sweeps of a n e t , but are s i m p l y c o n c e n t r a t e d and d i p p e d o u t . One u n i v e r s a l l y p r e f e r r e d c h a r a c t e r i s t i c of an e n c l o s u r e s t r u c t u r e i s t h a t i t be c o m p l e t e l y d r a i n a b l e or d r y a b l e , t o a i d i n r e p a i r and c l e a n i n g and t o h e l p r e t a r d d i s e a s e t r a n s m i s s i o n 73 (Huet, 1970). Burrows and Chenoweth (1970) o u t l i n e d o t h e r c r i t e r i a f o r e v a l u a t i n g the e f f i c i e n c y of pond d e s i g n s which can be a p p l i e d t o a l l e n c l o s u r e s . These a r e : 1 . C a r r y i n g c a p a c i t y — d e n s i t y and d i s t r i b u t i o n of the f i s h , oxygen a v a i l i b i l i t y and waste a c c u m u l a t i o n . 2. D i s e a s e i n h i b i t i o n — e d d i e s , a r e a s of no c u r r e n t ( d e a d s p o t s ) , m e t a b o l i t e g r a d i e n t s , 3. Food d i s t r i b u t i o n — water v e l o c i t y and food p a r t i . c l e r e s i d e n c e t i m e , o u t l e t t y p e , 4. C l e a n i n g e f f i c i e n c i e s — c u r r e n t d i s t r i b u t i o n , b i o l o g i c a l f o u l i n g , 5. V i a b i l i t y — s t a m i n a and muscle tone of r e a r e d f i s h . T h i s c h a p t e r g i v e s a s h o r t r e v i e w of the k i n d s of d e s i g n parameters and a l t e r n a t i v e s recommended f o r v a r i o u s e n c l o s u r e t y p e s , p a r t i c u l a r l y those f o r f i n f i s h a q u a c u l t u r e . b. E x t e n s i v e C u l t u r e The main p r i n c i p l e of a q u a c u l t u r e i s t o m a n i p u l a t e the d r i v i n g p h y s i c a l and b i o l o g i c a l v a r i a b l e s of the system. W i t h r e g a r d t o e n c l o s u r e s , t h i s means i m m i g r a t i o n , e m i g r a t i o n , p r e d a t i o n , food abundance and water q u a l i t y a r e c o n t r o l l e d as much as p o s s i b l e . In v e r y l a r g e or e x t e n s i v e s t a n d i n g water systems, f o r example r e s e r v o i r s , l a k e s , bays, e s t u a r i e s , i n l e t s or f j o r d s , t h i s i n v o l v e s s e g r e g a t i o n of the c u l t u r e d p o p u l a t i o n from the n a t u r a l p o p u l a t i o n u s i n g w e i r s , s c r e e n s , n e t s or a r t i f i c i a l or 74 n a t u r a l b a r r a g e s . P i s c i v o r o u s p o i s o n s may be used t o e l i m i n a t e u n d e s i r a b l e s p e c i e s b e f o r e the a r e a i s s t o c k e d w i t h the p r e f e r r e d s p e c i e s . G u i d e l i n e s f o r such management may be found i n Calhoun (1966), H a l l (1971), or Bennet (1971). The r a n c h i n g of salmon (Thorpe, 1980) i s a k i n d of e x t e n s i v e c u l t u r e where o n l y the f r e s h w a t e r phase of the a n i m a l ' s l i f e c y c l e i s under human c o n t r o l . The f i s h f o r a g e i n the w i l d d u r i n g t h e i r marine phase and then r e t u r n t o t h e i r stream or h a t c h e r y or o r i g i n where they a r e h a r v e s t e d on t h e i r way t o spawn. E n g i n e e r i n g d e s i g n of such massive e n c l o s u r e s as n e t s t o span the mouth of a f j o r d i s m a i n l y i n the r e a l m of marine e n g i n e e r i n g , where the s t r e s s f a c t o r s e x e r t e d on s t r u c t u r e s and m a t e r i a l s by c u r r e n t s , waves, wind and a b r a s i v e s d etermine the d e s i g n paramenters ( M i l n e , 1972; I v e r s o n , 1968). The f i s h e r i e s e n g i n e e r i n g d e t a i l s of s u i t a b l e net or s c r e e n s i z e and c o m p o s i t i o n t o maximize s e g r e g a t i o n w h i l e m i n i m i z i n g drag and b i o l o g i c a l f o u l i n g , must a l s o be taken i n t o c o n s i d e r a t i o n . E x t e n s i v e c u l t u r e i n f l o w i n g waters i s m a i n l y concerned w i t h the p r o t e c t i o n or enhancement of f i s h r e a r i n g h a b i t a t s , i n the form of stream c l e a r a n c e , watershed management, or h a b i t a t p r o t e c t i o n from l o g g i n g , m i n i n g and i n d u s t r i a l and m u n i c i p a l p o l l u t i o n s . There may be e f f o r t put i n t o e n g i n e e r i n g presumably optimum environments by b u i l d i n g s h e l t e r s , p o o l s , jams and d e f l e c t o r s i n t o streams ( L a g l e r , 1956, L i s t e r , 1980), or where c o n t r o l l e d spawning c h a n n e l s w i t h a s u i t a b l e s o r t i n g of g r a v e l , p r e f e r r e d water depth and c u r r e n t c r e a t e the ' p e r f e c t ' , ' n a t u r a l ' spawning and i n c u b a t i o n environment ( C l a y , 1961). 75 Beyond j u s t c o n t r o l l i n g the p h y s i c a l movement or c o n t a m i n a t i o n of c u l t u r e d p o p u l a t i o n s by e n c l o s i n g them, p r o d u c t i o n w i t h i n the e n c l o s u r e s can be augmented. D e n s i t i e s can be i n c r e a s e d t h rough s t o c k i n g a d d i t i o n a l a n i m a l s from more p r o d u c t i v e a r e a s or from h a t c h e r i e s . C a r r y i n g c a p a c i t i e s can be i n c r e a s e d or w i n t e r k i l l a v o i d e d through a e r a t i o n . A q u a t i c p r o d u c t i o n can be i n c r e a s e d by a d d i n g o r g a n i c f e r t i l i z e r s t o cause blooming growth i n the lower t r o p h i c l e v e l s . To augment the f i s h growth beyond t r y i n g t o i n c r e a s e the i n v e r t e b r a t e p r o d u c t i o n , the f i s h may be d i r e c t l y f e d s c r a p s or p e l l e t e d f e e d s . At t h i s p o i n t the management of c u l t u r e d p o p u l a t i o n s grades from e x t e n s i v e i n t o i n t e n s i v e c a r e , as the d e n s i t y and a r t i f i c i a l f e e d i n g frequency i n c r e a s e . c. Cage C u l t u r e Cage c u l t u r e , the containment of c u l t u r e d a n i m a l s i n l a r g e b o d i e s of water under a degree of c o n t r o l c h a r a c t e r i s t i c of i n t e n s i v e c u l t u r e , has become q u i t e p o p u l a r i n the l a s t t en y e a r s f o r many s p e c i e s of f i s h and s h e l l f i s h ( A l l s o p p , 1980). T h i s method i s p a r t i c u l a r l y a p p r o p r i a t e f o r t a k i n g advantage of the n a t u r a l p r o d u c t i v i t y of l a r g e b o d i e s of water w i t h o u t h a v i n g t o go t o a l o t of t r o u b l e i n r e c a p t u r i n g s t o c k e d f i s h . The n a t u r a l f e e d i n g may be more e f f i c i e n t l y augmented w i t h a r t i f i c i a l r a t i o n s i f the f i s h a r e c o n c e n t r a t e d i n s p e c i f i c , c o n t a i n e d a r e a s (Edwards, 1978). The o n l y p r e r e q u i s i t e s f o r a c o n t a i n e r b e i n g c a l l e d a cage or pen i s t h a t i t be a 3 d i m e n s i o n a l s t r u c t u r e e n c l o s i n g a l l 76 s i d e s , u s u a l l y w i t h the a i r on the water s u r f a c e f o r m i n g one boundary s i d e . The s t r u c t u r e u s u a l l y i s made up of a framework over "which i s s t r e t c h e d the w a l l f o r m i n g m a t e r i a l . Any c o n c e i v a b l e s u r f a c e shape may be used f o r the cage, the more p o p u l a r b e i n g s q uare, r e c t a n g u l a r , c i r c u l a r , hexagonal and o c t a g o n a l . The framework may be r i g i d l y f a s t e n e d t o g e t h e r , or may be a r t i c u l a t i n g so t h a t i t can bend and t w i s t i n response t o wave motion w i t h o u t b r e a k i n g up. More s o p h i s t i c a t e d cage d e s i g n may i n c l u d e s e m i - a u t o m a t i c h a r v e s t i n g , f e e d i n g or net c h a n g i n g mechanisms or r o t a b i l i t y t o h e l p c u r b f o u l i n g ( M c l n t y r e , 1981; B l a i r and B u r g e s s , 1979). D e s i r a b l e p r o p e r t i e s f o r framework m a t e r i a l are n o n - c o r r o s i v e n e s s , s t r e n g t h , f l e x i b i l i t y , l i g h t weight and bouyancy e i t h e r i n t r i n s i c i n the s t r u c t u r e or appended i n the form of f l o a t s . Most w a l l s of pens ar e made of mesh n e t t i n g or w i r e , t o f a c i l i t a t e the water and n a t u r a l food exchange between the i n t e r i o r and the o u t s i d e environment. D e s i r a b l e p r o p e r t i e s f o r w a l l m a t e r i a l i n t h i s k i n d of net pen are n o n - c o r r o s i v e n e s s , r e s i s t a n c e t o f o u l i n g , net s t r e n g t h , l i g h t w e i g h t and f l e x i b i l i t y , l a r g e net a p e r a t u r e s i z e but s m a l l and n o n - a b r a s i v e enough t o not harm the f i s h by s c r a p i n g or g i l l i n g . W a l l s may a l s o be made from non-porous m a t e r i a l i n c ases where l i m i t e d exchange w i t h the environment i s d e s i r e d , as i n the c o n t r o l l e d ecosystem p o l l u t i o n e x p e r i m e n t s (CEPEX) i n which case p l a s t i c f i l m s or p l a s t i c s h e e t s , r e i n f o r c e d or n o t , a r e a p p r o p r i a t e m a t e r i a l s . The s i z e of the pen i s u s u a l l y d e t e r m i n e d not so much by the optimum volume f o r r e a r i n g the a n i m a l s but r a t h e r by the 77 l a r g e s t s i z e which i s s t i l l manageable from a m a t e r i a l s h a n d l i n g v i e w p o i n t , a l t h o u g h cage s i z e may e f f e c t the growth r a t e of the f i s h ( K i l a m b i , et a l . , 1977). The ease of h a n d l i n g the net f o r h a r v e s t or c h a n g i n g i s of paramount importance when manpower and energy a r e e x p e n s i v e r e l a t i v e t o m a t e r i a l c o s t . O f t e n i t i s much more e c o n o m i c a l t o have many s m a l l pens than a few v e r y l a r g e pens. The e f f e c t i v e depth of the pen may p l a y an i m p o r t a n t p a r t i n i t s d e s i g n . For a q u a t i c p l a n t c u l t u r e e f f e c t i v e depth i s r e l a t e d t o the compensation depth of l i g h t p e n e t r a t i o n , where net p h o t o s y s n t h e s i s becomes l e s s than net r e s p i r a t i o n due t o l i g h t l i m i t a t i o n . For f i n f i s h or s h e l l f i s h c u l t u r e e f f e c t i v e depth i s more r e l a t e d t o the h a b i t a t p r e f e r e n c e of the a n i m a l s . For bottom d w e l l i n g a n i m a l s i t may be more a p p r o p r i a t e t o have s h a l l o w , c o m p l e t e l y e n c l o s e d and t o t a l l y submerged cages than t o waste m a t e r i a l w i t h deep w a l l s , whereas f i s h t h a t occupy the whole water column are b e t t e r h e l d i n deep s u r f a c e pens. C o v e r i n g s , even on s u r f a c e pens, may be used t o p r o t e c t the c u l t u r e d a n i m a l s from e x t e r n a l harm. M i s t n e t s or guy w i r e s w i l l h e l p keep out p r e d a t o r y b i r d s and opaque dark p l a s t i c s h e e t s w i l l p r o v i d e enough shade f o r l i g h t shy a n i m a l s . The p o s i t i o n i n which the cage i s moored w i l l make c o n s i d e r a b l e d i f f e r e n c e as t o i t s s uccess i n t a k i n g advantage of n a t u r a l p r o d u c t i o n or i n a v o i d i n g damage from waves, d r i f t i n g d e b r i s or c o l l i s i o n . These e f f e c t s a r e c o n t r a d i c t o r y , s i n c e the most n a t u r a l p r o d u c t i o n would pass t h r o u g h the net i f i t were i n a l i g h t c u r r e n t i n an exposed a r e a where i t would 78 a l s o encounter the most d r i f t w o o d and be most hazardous t o n a v i g a t i o n . The pen would be s a f e from the l a t t e r two f a c t o r s i n a p r o t e c t e d embayment, but the i n c r e a s e d b a r r i e r s would d e c r e a s e c u r r e n t and thus p l a n k t o n t r a n s p o r t . In s h a l l o w a r e a s the pens may be r i g i d l y a t t a c h e d t o the sea f l o o r by p i l i n g s d r i v e n i n t o the mud as i s t r a d i t i o n a l i n Southeast A s i a n pen c u l t u r e . In deeper a r e a s , or where more f l e x i b i l i t y of d e s i g n i s d e s i r e d , the s t r u c t u r e s a r e u s u a l l y moored t o heavy w e i g h t s s i t t i n g on the bottom. Some f i s h t h a t a r e p r e s e n t l y c u l t u r e d i n net pens, on a commercial b a s i s a re the rainbow t r o u t i n the U. S. A. (Hahn, 1974; C o l l i n s , 1972), Peru and Canada, the c a r p i n S i n g a p o r e , pompano a l o n g the G u l f Coast of the U. S. A.(Bardach et a l . , 1972) and y e l l o w t a i l tuna i n the I n l a n d Sea of Japan. d. Pond C u l t u r e The e a r t h e n f i s h pond i s the most a n c i e n t and s t i l l the most used e n c l o s u r e worldwide f o r the fa r m i n g of f i s h i n f r e s h water. We d e f i n e the pond as a c o m p l e t e l y e n c l o s e d , man-made c o n t a i n e r , u s u a l l y i n the macro range which i s c h a r a c t e r i z e d by low water f l o w thus low t u r n o v e r r a t e ( l e s s than one exchange per f i v e h o u r s ) and u s u a l l y w i t h e a r t h e n bottom and s i d e s . The pond may be used f o r m a i n t a i n i n g a c o n t r o l l e d n a t u r a l ecosystem, w i t h or w i t h o u t f e r t i l i z a t i o n t o i n c r e a s e n a t u r a l p r o d u c t i o n , or f o r i n t e n s i v e f i s h c u l t u r e f o r f i s h w i t h a low m e t a b o l i c oxygen demand or f o r l e s s dense c u l t u r e of more demanding f i s h . 79 The two most im p o r t a n t f e a t u r e s of a f i s h pond, as noted i n a l l of the r e f e r e n c e s on pond d e s i g n and c o n s t r u c t i o n , a r e t h a t the pond be w a t e r t i g h t , t o c o n s e r v e water, and t h a t i t be c o m p l e t e l y d r a i n a b l e , t o f a c i l i t a t e h a r v e s t , maintenance and p e s t c o n t r o l . Huet (1970) g i v e s a neat c l a s s i f i c a t i o n of v a l l e y t y p e , presuming t h a t most ponds w i l l be b u i l t s u p p l e m e n t a l t o n a t u r a l water c o u r s e s , and o u t l i n e s the p o t e n t i a l pond l a y o u t s which would be most s u i t a b l e f o r each v a l l e y . The p o i n t i s t h a t p l a n n i n g the s t r u c t u r e so t h a t i t w i l l f i t i n t o the topography of the s i t e i s much cheaper than d e s i g n i n g the s t r u c t u r e and then a l t e r i n g the topography t o s u i t . T h i s t a c t i c i s more a p p l i c a b l e t o s i t e s w i t h much s l o p e than t o r e l a t i v e l y f l a t l a n d , where any l a y o u t may be m a i n t a i n e d w i t h the same degree of e f f o r t , a l t h o u g h d r a i n i n g the ponds may be a problem. On s l o p i n g l a n d Huet's main c o n s t r u c t i o n s t r a t e g y i s t o b u i l d a s e r i e s of b a r r a g e s a c r o s s the water c o u r s e , o r , p r e f e r a b l y , t o b u i l d a s e r i e s of ponds o f f t o the s i d e ( s ) of a main c a n a l , such t h a t i n d i v i d u a l ponds may be emptied or f i l l e d i n d e p e n d e n t l y of each o t h e r . The shape of the pond i t s e l f , e s p e c i a l l y i f i t s mode of i n c e p t i o n was the damming of a stream, o f t e n conforms t o the c o n t o u r s of the l a n d and thus where the l a n d i s r e g u l a r , assumes a t r u n c a t e d o b l o n g shape, rounded and s h a l l o w a t the i n f l u e n t end and s t r a i g h t and deep a t the dam. Those ponds which a r e b u i l t by the e r e c t i o n of l e v e e s or the d i g g i n g of h o l e s i n f l a t t e r ground a r e u s u a l l y d e s i g n e d t o be r e c t a n g u l a r 80 i n a e r i a l view and of near c o n s t a n t d e p t h , w i t h a s l i g h t l y s l o p i n g bottom t o f a c i l i t a t e d r a i n i n g . The maintenance of s u i t a b l e depth of water i s m a i n l y a c h i e v e d through dams or l e v e e s , but o t h e r s t r u c t u r e s a r e o f t e n b u i l t i n t o t h e s e t o a i d i n d r a i n i n g , f i s h i n g out or more p r e c i s e l e v e l c o n t r o l . C o n t r o l s t r u c t u r e s s h o u l d have the p r o p e r t i e s of not e r o d i n g the embankment, f l e x i b i l i t y i n l e v e l c o n t r o l , and a b i l i t y t o d r a i n c o m p l e t e l y . W e i r s a re the most common and s i m p l e s t c o n t r o l s t r u c t u r e s , which a l s o may be used as water f l o w measurement d e v i c e s but seldom a r e . Coupled w i t h s c r e e n s , w e i r s can e f f e c t i v e l y keep f i s h i n the pond, but u n l e s s they a re c o n c r e t e and thus e x p e n s i v e , they o f t e n erode the bank and a r e d i f f i c u l t t o keep water t i g h t i f d e s i g n e d t o c o m p l e t e l y empty the pond. The monk i s a s o r t of l a r g e s t a n d p i p e s t r u c t u r e e r e c t e d w i t h i n the pond, w i t h a p i p e c o n n e c t i o n t h r o u g h the w a l l of the l e v e e or dam. T h i s d e v i c e i s h i g h l y recommended by Huet as the a l l purpose mechanism f o r l e v e l c o n t r o l i n ponds. H a r v e s t i n g the f i s h from the pond must be done by sweeps of a beach s e i n e net i n non d r a i n a b l e ponds, and s t i l l not a l l of the f i s h a r e caught, or p r e f e r a b l y i n c o n j u n c t i o n w i t h d r a i n i n g i n monk c o n t r o l l e d ponds. The pond i s d r a i n e d u n t i l water o n l y f i l l s a s m a l l c o n c r e t e h o l d i n g bay i n f r o n t of the monk, from which the f i s h can be d i p n e t t e d o u t . S t r a n d e d f i s h on the d r a i n e d pond bottom a r e r e t r i e v e d by hand ( H i c k l i n g , 1972). In d e v e l o p i n g c o u n t r i e s most s u p p l e m e n t a l f e e d i n g i s done 81 by hand, e i t h e r from the shore or from a boat rowed t o the c e n t r e of the pond. More f i s h f a r m e r s , p a r t i c u l a r l y c a t f i s h f a r m e rs i n the s o u t h e r n U. S. A. (Lee, 1973), a r e changing t o a u t o m a t i c f e e d e r s , which can f e e d the f i s h s m a l l e r amounts a t more f r e q u e n t i n t e r v a l s than i s p r a c t i c a l u s i n g manpower, and t h e r e b y more c l o s e l y match the f i s h ' s n a t u r a l c o n t i n u a l f e e d i n g b e h a v i o u r , i n c r e a s i n g growth r a t e s (Adron, 1972). Ponds most o f t e n have e a r t h e n s i d e s and bottoms m a i n l y because of the cheapness of s o i l . The type of s o i l i s v e r y i m p o r t a n t , both f o r i t s s e a l a n t q u a l i t i e s and f o r the c h e m i c a l s which may l e a c h out and a l t e r the water q u a l i t y . Some k i n d of c l a y i s the commonest m a t e r i a l f o r l i n i n g an o t h e r w i s e porous pond. R e c e n t l y , p l a s t i c l i n e r s a r e b e i n g used more e x t e n s i v e l y ; however, some p l a s t i c s ( p o l y v i n y l c h l o r i d e , p o l y p r o p y l e n e and p o l y e t h y l e n e ) use a p l a s t i c i z e r , d i o c t y l p h t h a l a t e , which may l e a c h t o t o x i c l e v e l s i f t h e r e i s l i t t l e f l o w t h r o u g h the pond. S e v e r a l days of f l u s h i n g w i t h warm water w i l l b r i n g the c o n c e n t r a t i o n down t o a s a f e , background l e v e l (Carmangini and Bennet, 1976). The s t a b i l i t y of the s i d e s depends on t h e i r s l o p e , t h e i r m a t e r i a l s t a b i l i t y , and the d i s t a n c e a c r o s s the pond, which d e t e r m i n e s the p o s s i b l e wave h e i g h t and s c o u r i n g a c t i o n (Wheaton, 1977). Most pond f a r m e r s encourage v e g e t a t i o n t o grow a l o n g the edges of t h e i r e a r t h e n ponds t o s t a b i l i z e the banks, a l t h o u g h pond weeds a r e u s u a l l y d i s c o u r a g e d s i n c e they crowd the f i s h and can harbour d i s e a s e v e c t o r s . E a r t h e n ponds are e a s i l y r e p a i r e d i f slumping does o c c u r . The q u a l i t y of the water i n the pond i s v e r y i m p o r t a n t f o r 82 the w e l l b e i n g of the f i s h and can be m a n i p u l a t e d i n many ways. A r t i f i c i a l a e r a t i o n , e i t h e r t h rough s p l a s h i n g i n f l o w i n g water or c i r c u l a t i n g pond water through s u r f a c e m e c h a n i c a l a e r a t o r s , can g r e a t l y i n c r e a s e the c a r r y i n g c a p a c i t y of a pond, s i n c e the two most common l i m i t i n g f a c t o r s , low oxygen and h i g h ammonia c o n c e n t r a t i o n , a r e both a l l e v i a t e d by s p l a s h a e r a t i o n . Blooms of a l g a e can be c o n t r o l l e d e i t h e r by f l u s h i n g the pond w i t h low n u t r i e n t water, t r e a t i n g w i t h copper s u l p h a t e or a d d i n g b i o l o g i c a l c o n t r o l such as h e r b i v o u r o u s z o o p l a n k t o n or f i s h . Only the f i r s t a l t e r n a t i v e i s r e a l l y s u i t a b l e s i n c e the o t h e r two can have u n p r e d i c t a b l e and u n d e s i r a b l e s i d e e f f e c t s . For the c o n t r o l of unwanted i n t r u d e r s , the c u r e must be s p e c i f i c t o the mode of a t t a c k . Pathogens a r e kept out by c a r e f u l s e p a r a t i o n of the water from n a t u r a l p o p u l a t i o n s , by q u a r a n t i n i n g new s t o c k and by p e r i o d i c a l l y d r a i n i n g , d r y i n g and even l i m i n g the ponds. P r e d a t o r s a r e kept out by m i s t n e t s , guy w i r e s , f e n c e s and t r a p s . P o l l u t a n t s a r e kept out by c a r e f u l s e l e c t i o n and m o n i t o r i n g of the water source and l o c a t i o n . e. Raceway C u l t u r e The raceway can be d e f i n e d as a f i s h h o l d i n g c o n t a i n e r which has a s t o c k i n g d e n s i t y much g r e a t e r than those found i n n a t u r a l waters and which i s c h a r a c t e r i z e d by r e l a t i v e l y h i g h water f l o w r a t e s and h i g h volume t u r n o v e r ( g r e a t e r than one exchange per t h r e e h o u r s ) . N a t u r a l p r o d u c t i o n i n raceways i s u s u a l l y n e g l i g i b l e , a l t h o u g h those w i t h e a r t h e n f l o o r s may get some emergent b e n t h i c l a r v a e . Raceways a r e becoming more 83 p o p u l a r as space becomes l i m i t e d and good a r t i f i c i a l feeds become a v a i l a b l e , s i n c e they a r e u s u a l l y c o n s i d e r a b l y s m a l l e r than ponds f o r c o n t a i n i n g the same biomass of f i s h . The l a y o u t of a group of raceways i s l e s s s u b j e c t t o the l a y of the l a n d than f o r ponds, due t o the s m a l l e r s i z e and u s u a l r i g i d s i d e c o n s t r u c t i o n . Most farms and h a t c h e r i e s a r r a n g e t h e i r raceways i n a manner f o r most e f f i c i e n t m a t e r i a l s h a n d l i n g r a t h e r than use of topography (see a p p e n d i c e s of K l o n t z , 1974, f o r e xamples). Many modern f a c i l i t i e s have t h e i r raceways a r r a n g e d f o r m u l t i p l e pass water r e u s e , w i t h some k i n d of water t r e a t m e n t d e v i c e i n between, t o more e f f i c i e n t l y make use of the a v a i l a b l e water. M u l t i p l e use can e i t h e r be i n the form of s e r i a l passage through s e v e r a l banks of raceways or r e c y c l i n g reuse f o r one bank. There a r e two b a s i c d e s i g n shapes f o r raceways, c i r c u l a r and r e c t a n g u l a r , t h e i r use b e i n g based on the swimming p r e f e r e n c e of the f i s h and the o c c u r r e n c e of 'dead s p o t s ' i n the water exchange p r o f i l e s . The main t e n e t of the raceway d e s i g n i s t o make each c u b i c meter of water as n e a r l y as p o s s i b l e l i k e every o t h e r c u b i c meter (Buss and M i l l e r , 1971). C i r c u l a r raceways a r e v e r y s i m i l a r i n d e s i g n , w i t h i n l e t j e t s on the s u r f a c e and an o u t l e t s t a n d p i p e i n the c e n t e r (Larmoyeux, et a l . , 1973) ( F i g u r e 6 ) . These a r e p r e f e r r e d f o r f r y and f i n g e r l i n g s because of the ease i n c o n t r o l l i n g c u r r e n t v e l o c i t y and because s m a l l f i s h do not seem t o mind swimming i n c i r c l e s . For l a r g e r f i s h , r e c t a n g u l a r raceways a r e p r e f e r r e d . These a r e more space c o n s e r v a t i v e and can have a h i g h t u r n o v e r 84 Construction of circular pool. A) PLAN VIEW OF CIRCULAR POND VEHV LOW VELOCITY ! 1 LOW' fc~?0' *x,i i "»$ .SLOPE * v "* UCOtUM VELOCITY ,- a* STa PIPC OUTLET 0) SECTION -flaw pattom in drcular pond. a. Plan view; b. Flow pal tarn around tcroan; c. NoixJe) d. Stolon. F i g u r e 6. C i r c u l a r raceways(from Huet, 19 72[top] and Burrows and Chenoweth, 1955[bottom]). 85 r a t e w i t h o u t i n d u c i n g h i g h c u r r e n t v e l o c i t i e s . Due t o the h i g h f l o w r a t e s , and thus s c o u r i n g a b i l i t y of the water i n raceways, they a r e almost u n i v e r s a l l y r i g i d s t r u c t u r e s , w a l l e d w i t h wood, c o n c r e t e , c o a t e d m e t a l or p l a s t i c . Wooden raceways o f t e n have e a r t h e n f l o o r s but most modern f a c i l i t i e s have the e n t i r e e n c l o s u r e made of non porous c o n c r e t e or p r e f a b r i c a t e d metal or p l a s t i c s e c t i o n s , m a i n l y t o a i d i n complete d r y i n g and c l e a n i n g and t o ward o f f d i s e a s e organism t r a n s m i s s i o n . S i n c e the c u l t u r e d a n i m a l s a r e a l r e a d y q u i t e c o n c e n t r a t e d i n raceways and s i n c e the w a l l s a r e made of r i g i d m a t e r i a l s , t h e r e i s no need f o r monk-type s t r u c t u r e s , as recommended f o r ponds, and end w e i r s , s t a n d p i p e s and d r a i n s a r e most common. D r a i n s which empty the raceway from near the lo w e s t p o i n t a t the d i s t a l end from the i n f l o w a r e u s u a l l y b e s t s u i t e d f o r t r a n s p o r t i n g s o l i d wastes away from the f i s h environment. Feeding a n i m a l s i n raceways can e a s i l y be done by hand or by a u t o m a t i c f e e d e r ( P i p e r et a l , 1982). Feeders can be powered by many means: e l e c t r i c i t y ( b a t t e r y or m a i n s ) , s o l a r ( M c l n t y r e , 1981), compressed a i r or by the f i s h t h e m s e l v e s . Complete r a t i o n s must be f e d due t o the l a c k of n a t u r a l p r o d u c t i o n . The main problem w i t h f e e d i n g i n raceway c u l t u r e i s the s t o r a g e of the r e q u i r e d l a r g e q u a n t i t y of f i s h f e e d . S i n c e t h e s e feeds a r e most o f t e n made of q u i t e u n s t a b l e c o m p o n e n t s - - h e r r i n g meal, f i s h o i l , y e a s t s , v e g e t a b l e meals w i t h h i g h p o l y u n s a t u r a t e d f a t t y a c i d c o n c e n t r a t i o n s - - s t o r a g e of the bes t meals must be i n f r e e z e r s . There i s much ongoing r e s e a r c h i n t o the f o r m u l a t i o n 86 of i n e x p e n s i v e , dry d i e t s , p a r t i c u l a r l y f o r s a l m o n i d s . Water q u a l i t y i s m a i n t a i n e d i n the same manner i n raceways as i n ponds, by e n s u r i n g a good c l e a n , pathogen f r e e water s o u r c e and a e r a t i n g or t r e a t i n g the water as n e c e s s a r y . The r i g i d s i d e s and bottom of raceways o f t e n c o n t r a c t b i o l o g i c a l f o u l i n g , the b u i l d - u p of a l g a l or f u n g a l scums, but these can be c o n t r o l l e d through i n c r e a s e d water f l o w and p e r i o d i c d r a i n i n g , d r y i n g and s c r u b b i n g . f. Salmonid F a c i l i t i e s In a d d i t i o n t o the c o n t a i n e r s mentioned, t h e r e are some f i s h farm f a c i l i t i e s which are p e c u l i a r t o the p a r t i c u l a r f i s h b e i n g c u l t u r e d . Salmonid c u l t u r e i s v e r y w e l l d e v e l o p e d and the f a c i l i t i e s used i n the c o n t r o l of t r o u t l i f e h i s t o r y are w e l l c o d i f i e d . The purpose of any f i s h e n c l o s u r e i s t o c o n t a i n the f i s h w h i l e p r o v i d i n g the a n i m a l s w i t h the b e s t , e c o n o m i c a l l y p o s s i b l e environment f o r t h e i r h e a l t h and growth. For s a l m o n i d s , growth o c c u r s most r a p i d l y a t around 15°C whereas h e a l t h i s m a i n t a i n e d b e s t a t around 10°C. Salmonid eggs i n n a t u r e i n c u b a t e i n v e r y c o l d water (0-5°C) and c o l d t e m p e r a t u r e s f o r i n c u b a t i o n i n the h a t c h e r y a r e recommended t o keep d i s e a s e away from the eggs, which have poor r e s i s t a n c e (Herman, 1970). The egg stage r e q u i r e s h i g h oxygen c o n c e n t r a t i o n s i n the water, a l s o h e l p e d by c o l d t e m p e r a t u r e s ( L e i t r i t z and L e w i s , 1976). The f i r s t s a l m o n i d eggs were hatched i n j a r i n c u b a t o r s , w hich i s s t i l l a good method f o r h a t c h i n g as l o n g as the water 87 i s w e l l a e r a t e d f i r s t . More commonly used nowadays are u p f l o w i n g screenbottom t r a y s , a r r a n g e d e i t h e r i n s t a c k s or a l o n g t r o u g h s ( F i g u r e 2 ) . The s c r e e n mesh i s chosen t o be s l i g h t l y s m a l l e r than the egg d i a m e t e r so t h a t when the eggs h a t c h , the a l e v i n s can s l i p t h r o u g h i n t o the t r o u g h proper (Senn, et a l . , 1973). The f l o w r a t e i s a d j u s t e d t o keep the oxygen c o n c e n t r a t i o n h i g h and t o wash away wastes and c a s t o f f egg s h e l l s w i t h o u t o v e r l y a g i t a t i n g the eggs. S m a l l raceway t r o u g h s a r e u n i v e r s a l l y used t o h o l d the a l e v i n s u n t i l swim-up. The f l o w r a t e can be q u i t e h i g h i n the t r o u g h s s i n c e the a l e v i n s l a y i n the low c u r r e n t boundary l a y e r on the t r o u g h bottom. F u l l s i z e d raceways are most o f t e n r e c t a n g u l a r . A c o m b i n a t i o n of the good q u a l i t i e s of the r e c t a n g u l a r and the c i r c u l a r raceways i s found i n the r e c t a n g u l a r r e c i r c u l a t i n g raceway of Burrows and Chenoweth (1970) ( F i g u r e 7 ) . T h i s i s a d i v i d e d r e c t a n g u l a r raceway (50-75 f t . l o n g by 17 f t . wide) w i t h i n f l o w a t the ends and o u t f l o w i n the c e n t r e , i n d u c i n g a c y c l o n i c c i r c u l a t i o n p a t t e r n , a i d e d by c u r r e n t b a f f l e s p l a c e d a t the c o r n e r s . The raceway i s s e l f - c l e a n i n g a t i n p u t s i n e x c e s s of 400 g a l l o n s per m i nute. Beamish et a l . (1975) c o n c e i v e d an i n e x p e n s i v e p l a s t i c l i n e d raceway ( F i g u r e 8) i t s d e s i g n does not a l l o w f o r as e f f i c i e n t use of water as does the Burrows raceway, but the c o m p a r a t i v e c o s t ($35,000 per u n i t compared t o $100,000 per u n i t ) i s v e r y a t t r a c t i v e . Even l e s s e x p e n s i v e and s t i l l d u r a b l e are l a r g e o v a l above ground swimming p o o l s ( a t $2,300 each) which per f o r m the same f u n c t i o n 89 Cross-Section of Row . 90 of h o l d i n g water as do the more s o l i d s t r u c t u r e s . Replacement l i n e r s a re o n l y $500 each, due t o mass p r o d u c t i o n . An a l t e r n a t i v e raceway which has r e c e i v e d much a t t e n t i o n i n the l a s t few y e a r s i s the v e r t i c a l raceway or ' s i l o ' of Buss, G r a f f and M i l l e r (1970) and suggested f o r an i n t e n s i v e r e c i r c u l a t i o n f a c i l i t y by MacDonald et a l . (1975, F i g u r e 9 ) . Each u n i t i s made from a c o n v e r t e d o i l s t o r a g e tank w i t h a 5,450 g a l l o n (U.S.) water c a p a c i t y , and h o l d s 20,000 f i s h . The i n t a k e p i p e , 8 i n c h e s from the bottom, d i s c h a r g e s 215-450 gpm of water, g i v i n g 2.5-5.0 exchanges per hour. The s i l o i s s e l f - c l e a n i n g ( i n c l u d i n g dead f i s h which r i s e t o the s u r f a c e and can be removed), g i v e s an even, random f i s h d i s t r i b u t i o n , and i s r e l a t i v e l y p o r t a b l e and e a s i l y r e l o c a t e d . The p r o d u c t i o n per c u b i c f o o t of volume (8.53 l b s . ) i s h i g h compared t o normal (1.5 l b s . ) but the h i g h exchange r a t e makes p r o d u c t i o n per amount of water i n p u t (13.8 lbs./gpm) low, t h u s t h i s raceway i s p a r t i c u l a r l y s u i t a b l e t o s i t e s w i t h l o t s of water and not much space, due t o the s m a l l s u r f a c e a r e a and the h i g h exchange r a t e s used. S i m i l a r u n i t s are used f o r t r o u t c u l t u r e i n New Mexico (Moody and McCleskey, 1978). The Mundie (1974, 1980) ( F i g u r e 10) c h a n n e l , an a r t i f i c i a l r i f f l e - p o o l sequence t o emulate a n a t u r a l stream, i s an i n t e r e s t i n g f r y r e a r i n g a l t e r n a t i v e which t a k e s advantage of n a t u r a l p r o d u c t i o n by i n t e n s i f y i n g s t a n d a r d stream management t e c h n i q u e s ( L i s t e r , 1980; L a g l e r , 1956), and c o u l d c o n c e i v a b l y be used t o r e a r l a r g e r f i s h than f r y . Figure 9. An Example of V e r t i c a l Raceway Use. From MacDonald et a l . , 1975. StrtomUd* Vtgttaiien "An4 Soil* Leaf Lttfr Soil L 9 aching Torrottrlml Intoct* Dlmolvtd Organic* Figure 10. Stream Improvement, a. from Lagler(1956) shows the use of def lectors in improving habitat ; b. from Mundie(1974, 1978) shows a cross-section of the a r t i f i c i a l channel and the benefits of the r i f f l e - p o o l sequence. U3 93 E. Post R e a r i n g a. I n t r o d u c t i o n U n l e s s the f i s h a r e r e a r e d f o r l i v e f i s h i n g out of t h e i r r e a r i n g e n c l o s u r e , they must be handled i n some way b e f o r e b e i n g marketed. T h i s h a n d l i n g i s always a t l e a s t p a r t l y the r e s p o n s i b i l i t y of the f i s h farmer and r e q u i r e m e n t s f o r h a r v e s t , p r o c e s s i n g , s t o r a g e and t r a n s p o r t must be c o n s i d e r e d i n the d e s i g n of an a q u a c u l t u r e f a c i l i t y . b. H a r v e s t The f i r s t t a s k i n h a r v e s t i n g a q u a t i c a n i m a l s i s t o c o n c e n t r a t e them i n t o a c o n f i n e d volume of water, from which they can be e a s i l y c a p t u r e d and ha n d l e d . Von Brandt (1972) o u t l i n e s many ways of c a p t u r i n g f i s h i n e x t e n s i v e w a t e r s . T h i s i s done i n raceway and pond c u l t u r e by l o w e r i n g the l e v e l of the water and i f the bottom of the e n c l o s u r e s l o p e s downward t o one end, the f i s h w i l l be c o n c e n t r a t e d t h e r e . The pond or raceway can a l s o be d r a i n e d , w i t h the f i s h , i n t o a s m a l l e r catchment b a s i n , i n s i d e or o u t s i d e the main e n c l o s u r e w a l l s . D r a g n e t s , beach s e i n e s or l a r g e s c r e e n b a r r i e r s a r e a l s o used t o move the f i s h t o one end i n ponds and raceways. In net pens, the net need o n l y be l i f t e d p a r t i a l l y out of the water t o c o n c e n t r a t e the f i s h . D i p n e t s or g a f f s a r e used f o r the a c t u a l c a p t u r e and h a n d l i n g of f i s h , and t r a n s f e r t o the p r o c e s s i n g area i s made 94 i n tubs or t a n k s . G r a v i t y systems of s l u i c e s , p i p e s or c a n a l s can c u t down h a n d l i n g c o n s i d e r a b l y , but s i n c e the ponds and raceways a r e u s u a l l y below ground l e v e l some k i n d of h o i s t i s r e q u i r e d t o r a i s e the f i s h t o the s l u i c e e n t r a n c e . Such h o i s t s may be m e c h a n i c a l , e l e v a t o r - t y p e boxes, n e t s on h y d r a u l i c booms, or f i s h pumps, the mechanics of a l l of which can be adapted from t h o s e used on c ommercial f i s h i n g v e s s e l s . The l a s t h a n d l i n g r e q u i r e m e n t b e f o r e p r o c e s s i n g i s t o s o r t the f i s h i n t o the s i z e s a p p r o p r i a t e f o r d i f f e r e n t markets, which can be done e i t h e r m a n u a l l y or m e c h a n i c a l l y . c. P r o c e s s i n g There a r e many d i f f e r e n t t y p e s of p r o d u c t s from a q u a c u l t u r e farms, and t h e r e may even be s e v e r a l d i f f e r e n t s a l e a b l e forms of the same f i s h s p e c i e s from the same farm. L i v e s a l e of f i s h can be as f o l l o w s : eggs, f r y or f i n g e r l i n g s , t o o t h e r f a r m e r s or groups i n t e r e s t e d i n s t o c k i n g p r i v a t e w aters f o r commercial or r e c r e a t i o n a l use; or as f u l l s i z e d f i s h t o the same o r g a n i z a t i o n s or t o r e s t a u r a n t s , f i s h d e a l e r s or p r i v a t e i n d i v i d u a l s who w i s h t o d i s p l a y the f i s h b e f o r e they are c l e a n e d f o r e a t i n g . P r o c e s s e d f i s h may be s o l d : f r e s h i c e d or f r o z e n , d r e s s e d or f i l l e t e d ; p r e s e r v e d , canned, s a l t e d , d r i e d , smoked, or p i c k l e d ; or as b i - p r o d u c t , F i s h P r o t e i n C o n c e n t r a t e , f i s h c a k e s , f i s h meal or f i s h o i l . D i f f e r e n t f i s h e s , depending on the f l e s h c o l o u r , c o n s i s t e n c y and o i l i n e s s , or the amount of bone p r e s e n t and on t r a d i t i o n , s u i t d i f f e r e n t p r o c e s s i n g methods (Burgess et a l . , 1965). 95 R e g a r d l e s s of the f i n a l p r o d u c t , w i t h the e x c e p t i o n of l i v e s a l e , the f i s h farmer i s u s u a l l y a t l e a s t r e s p o n s i b l e f o r the c l e a n i n g and d r e s s i n g of the f i s h on s i t e . Immediate d r e s s i n g - and i c i n g a f t e r removal from the r e a r i n g water i s v e r y i m p o r t a n t i n p r e s e r v i n g the t e x t u r e and f r e s h n e s s of the f l e s h and h e l p s reduce a u t o l y s i s . M e c h a n i c a l e v i s c e r a t o r s have been de v e l o p e d which work v e r y w e l l f o r f i s h t h a t a r e of the same shape and s i z e , a l t h o u g h the p r o h i b i t i v e c o s t of these machines makes most s m a l l f i s h f a r m i n g o p e r a t o r s do t h e i r c l e a n i n g by hand. The d r e s s i n g p r o c e s s i n v o l v e s removing o n l y the v i s c e r a , but f i l l e t i n g a l s o removes the head, t a i l , f i n s and most of the bones. The f l e s h can be e x t r u d e d from the boney p a r t s i n a deboning machine i n which the f i s h i s p r e s s e d a g a i n s t a s i e v e . The f l e s h oozes through and the bones remain b e h i n d . T h i s p r o c e s s d e s t r o y s the o r i g i n a l c o n s i s t e n c y of the f l e s h but i s u s e f u l f o r v e r y boney f i s h or f o r e x t r a c t i n g the f l e s h from p o r t i o n s d i s c a r d e d i n f i l l e t i n g , which can then be made i n t o f i s h c a k e s . A c e r t a i n amount of plumbing i s r e q u i r e d f o r an e f f i c i e n t d r e s s i n g o p e r a t i o n f o r washing down the f i s h and washing away the wastes. S a n i t a t i o n i s a l s o of utmost importance t o i n h i b i t pathogen t r a n s f e r . G u i d e l i n e s f o r the d e s i g n of p r o c e s s i n g and h a n d l i n g f a c i l i t i e s a re v e r y w e l l p r e s e n t e d i n Lane (1974). The f i s h p r o c e s s i n g wastes and the t a i l w a ters from the washing up are a c t u a l l y v e r y n u t r i t i o u s h i g h p r o t e i n s u b s t a n c e s and need not be wasted by t r e a t i n g as sewage or r e f u s e . There i s a g r e a t t e m p t a t i o n t o f e e d such wastes back t o the r e a r i n g f i s h , 96 a l t h o u g h t h i s i s not recommended as i t would undoubtably spread the o c c u r r e n c e of p a r a s i t e s and pathogens but f e e d i n g t o l i v e s t o c k or p o u l t r y as n u t r i e n t supplements would be a c c e p t a b l e . d. S t o r a g e The ' s h e l f l i f e ' or s t o r a g e s t a b i l i t y i s l e n g t h e n e d by many t h i n g s , amomg them: h a v i n g f i s h i n good c o n d i t i o n b e f o r e k i l l i n g , a l l o w i n g as l i t t l e time as p o s s i b l e between k i l l i n g , d r e s s i n g and i c i n g , making the d r e s s i n g p r o c e d u r e complete and the c o n d i t i o n s s a n i t a r y , and, most i m p o r t a n t l y , s t o r i n g a t a c o l d t e m p e r a t u r e . A l l c a t a b o l i c p r o c e s s e s d e c r e a s e w i t h d e c r e a s i n g temperature t o z e r o degrees C e l s i u s , below which i c e c r y s t a l l i z a t i o n w i l l p a r t i a l l y degrade f l e s h f i r m n e s s . One v e r y good way t o s t o r e f i s h f o r complete f r e s h n e s s i s t o s t o r e them a l i v e i n water, g i v i n g them a minimum maintenance d i e t u n t i l the market can take them. C o l d water s p e c i e s l i k e t r o u t can be kept i n r u n n i n g water below z e r o degrees C e l s i u s f o r as l o n g as d e s i r e d and the c o l d n e s s of the water a c t u a l l y improves the f i r m n e s s of the f l e s h (Beamish e t a l . , 1975). The f i s h farmer or w h o l e s a l e r may need some c o l d s t o r a g e space t o keep i c e d f i s h w a i t i n g f o r the r e t a i l market, but b e t t e r communication between farmer and r e t a i l e r can have f i s h h e l d a l i v e u n t i l the market i s ready f o r them. S t o r a g e room on the farm i s more o f t e n needed f o r the f i s h f e e d s , some of which need t o be kept f r o z e n u n t i l a few hours b e f o r e use and a l l of which need c l e a n d r y space. The s i z e of the s t o r a g e a r e a 97 r e q u i r e d depends on the volume of the f e e d needed between shipment p e r i o d s and the a v a i l a b i l i t y and r e l i a b i l i t y of f e e d s u p p l i e s . Some k i n d of a i r c o n d i t i o n i n g or r e f r i g e r a t i o n i s recommended f o r any l a r g e s t o r a g e a r e a . e. T r a n s p o r t L i v e f i s h a re u s u a l l y v e r y d e n s e l y crowded d u r i n g t r a n s p o r t , t o c u t down the weight of water c a r r i e d , (McCraren and J o n e s , 1978), and t h i s c o n c e n t r a t i o n causes c o n s i d e r a b l e s t r e s s i n the f i s h u n l e s s v e r y a c t i v e s t e p s a r e taken t o p r o v i d e s u f f i c i e n t oxygen and t o get r i d of m e t a b o l i c wastes(ammonia). To l e s s e n the m e t a b o l i c waste p r o d u c t i o n and d e c r e a s e oxygen consumption and i n c r e a s e the oxygen s o l u b i l i t y of the t r a n s p o r t water, t r a n s p o r t t a n k s can be c o o l e d t o t e m p e r a t u r e s w e l l below the r e a r i n g t e m p e r a t u r e . For s h o r t h a u l s , i c e packed around the f i s h tank may be s u f f i c i e n t but l a r g e , l o n g h a u l s are b e t t e r o f f w i t h m e c h a n i c a l r e f r i g e r a t i o n u n i t s . A e r a t o r s , p r e f e r a b l y u s i n g pure oxygen, are a must f o r any t r a n s p o r t . A e r a t i o n s h o u l d be v i g o r o u s , more t o bubble out ammonia than t o s a t u r a t e w i t h oxygen. L i v e t a n k s s h o u l d be r i g i d , s t r o n g and water p r o o f , made of n o n - t o x i c f i b r e g l a s s , s t e e l or aluminum, i n s u l a t e d w i t h a l a r g e opening on t o p for-l o a d i n g and a double doored s l u i c e gate a t the bottom which can be a t t a c h e d t o p i p e s or s l u i c e s f o r u n l o a d i n g the water and f i s h t o g e t h e r . Every farmer s h o u l d have a s u p p l y of a i r s t o n e s , r e g u l a t o r s , h o s i n g , a i r or oxygen t a n k s , and a f r e e z e r or i c e -making machine t o accompany t r a n s p o r t t a n k s . 98 Dress e d f i s h a r e l e s s f i n i c k y t o t r a n s p o r t s i n c e water and a e r a t i o n a r e unnecessary, b u t , c o n c u r r e n t t o the arguments g i v e n under s t o r a g e f o r the s p o i l a g e of f i s h , i c i n g or r e f r i g e r a t i o n i s a must. Any s u i t a b l e s i z e wooden or p r e f e r a b l y p l a s t i c c o n t a i n e r can be used f o r h o l d i n g a l t e r n a t e l a y e r s of d r e s s e d f i s h and c r u s h e d i c e . C l e a n l i n e s s a t t h i s end of the o p e r a t i o n i s paramount and the farmer s h o u l d have f a c i l i t i e s f o r c l e a n i n g and s t o r i n g r e u s a b l e c o n t a i n e r s , as w e l l as machinery f o r i c e - m a k i n g . T r a n s p o r t of f i s h w i t h i n the f a c i l i t y i t s e l f can be g r e a t l y f a c i l i t a t e d by u s i n g i n t e r c o n n e c t e d c h a n n e l s or i n c l i n e d p i p i n g systems t o a v o i d h a n d l i n g and l i f t i n g ( T h e i s , 1978). F. Lower L e v e l C u l t u r e a. I n t r o d u c t i o n T h i s s e c t i o n o u t l i n e s some d e s i g n parameters t o c o n s i d e r f o r the mass c u l t u r i n g of food organisms f o r f e e d i n g t o f i s h , s t a r t i n g w i t h n u t r i e n t medium and working t h r o u g h p r i m a r y and secondary p r o d u c e r s . The g o a l i n d e s i g n i n g any k i n d of a q u a c u l t u r e system, i n c l u d i n g one f o r the mass c u l t u r e of organisms low i n the food c h a i n , i s t o p r o v i d e an o p t i m a l l y s u i t a b l e environment f o r growth and r e p r o d u c t i o n . D i f f e r e n t organisms have d i f f e r e n t 99 growth s t i m u l a t i n g r e q u i r e m e n t s , which can l e a d t o c o n f l i c t i f an a n i m a l i s grown i n the same v e s s e l as i t s food i t e m s . Some a l g a e r e l e a s e s u b s t a n c e s which a r e t o x i c t o h i g h e r t r o p h i c l e v e l s , e s p e c i a l l y when i n bloom ( P r e s c o t t , 1948). Taub and D o l l a r (1964a and 1964b) and Ryther (1954) found d i f f i c u l t y i n e s t a b l i s h i n g a n u t r i t i o n a l l y c o m p a t i b l e medium f o r C h l o r e l l a and Daphnia c u l t u r e . They can be c u l t u r e d s e p a r a t e l y but I v l e v a (1973) n o t e s t h a t i f they a r e , space i s wasted because i t t a k e s so much l e s s space t o grow the a l g a e r e q u i r e d because the a l g a e t o l e r a t e much g r e a t e r d e n s i t i e s than the Daphnia. However, s i n c e the b i o l o g i c a l r e q u i r e m e n t s of p r i m a r y and secondary p r o d u c e r s a r e more c l e a r l y d e f i n a b l e i f s e p a r a t e d , the d e s i g n of t h e i r c u l t u r e s s h a l l be c o n s i d e r e d s e p a r a t e l y . Two l i t e r a t u r e s o u r c e s were e x p l o r e d f o r t h i s s e c t i o n , t h a t i n v o l v i n g a l r e a d y a ttempted mass c u l t u r e , and t h a t i n v o l v i n g l a b o r a t o r y c u l t u r e of lower t r o p h i c organisms. The works on mass c u l t u r e g i v e us an i n s i g h t i n t o the g e n e r a l r e l i a b l i l i t y , r u l e s and c o m p l i c a t i o n s i n v o l v e d i n mass c u l t u r e . Mass c u l t u r e s , however, are too o f t e n f u l l of u n c e r t a i n t i e s because of the l a c k of c o n t r o l e x h i b i t e d . L a b o r a t o r y c u l t u r e s p r o v i d e us w i t h more q u a n t i f i a b l e d a t a on the response of the c u l t u r e s t o v a r i o u s d r i v i n g v a r i a b l e s . I t i s a l s o p o s s i b l e t o s c a l e up some l a b o r a t o r y c u l t u r e p r o c e e d u r e s and a p p a r a t u s t o m a i n t a i n the same degree of c o n t r o l over the pa r a m e t e r s . Persoone and S o r g e l o o s (1975) s e t down some key r u l e s f o r the c u l t u r e of l a b o r a t o r y s c a l e c u l t u r e s . S l i g h t l y m o d i f i e d , t h e s e a r e : 1 0 0 1. O x y g e n a t e ( a e r a t e ) g e n t l y , w i t h o u t d i s t u r b i n g t h e a n i m a l s ; 2 . K e e p t h e f o o d i n s u s p e n s i o n — a v o i d s e d i m e n t a n d b a c t e r i a l a n d f u n g a l scum d e v e l o p m e n t ; 3 . A v o i d c o m p l e x s y s t e m s — t h e m o r e c o m p o n e n t s a n d m e c h a n i s m s t h e r e a r e , t h e g r e a t e r i s t h e p r o b a b i l i t y o f f a i l u r e ( t h i s p o i n t was e m p h a s i z e d by D r . F r e i d a T a u b , ( p e r s . c o m m . ) , who s t a t e d t h a t m o s t a l g a l a n d z o o p l a n k t o n c u l t u r e s c r a s h o u t b e c a u s e o f f a i l u r e i n t h e m e c h a n i c a l s u p p o r t s y s t e m s , n o t i n t h e b i o l o g i c a l m e c h a n i s m s ) ; 4 . A u t o m a t e a s much a s p o s s i b l e — w h i l e d e c r e a s i n g l a b o u r c o s t s , t h i s a l s o l e a d s t o e f f i c i e n t d e s i g n , b e a r i n g i n m i n d n o . 3 ; 5 . U s e i n e r t s o u r c e s o f f o o d a n d m i n i m i z e t h e l i n k s b e t w e e n n u t r i e n t a n d t a r g e t s p e c i e s ; 6. A v o i d l a b s y s t e m s w h i c h c a n n o t be s c a l e d u p t o m a s s c u l t u r e s y s t e m s . R e g a r d l e s s o f t h e t y p e o f o r g a n i s m c u l t u r e d , t h e s y s t e m may be o p e r a t e d i n b a t c h , p e r i o d i c o r c o n t i n u o u s m o d e . B a t c h mode r e f e r s t o t h e p r o c e s s o f i n o c u l a t i n g a c u l t u r e v e s s e l w i t h a n o r g a n i s m a n d i t s n u t r i e n t o r f o o d s o u r c e , a l l o w i n g s u f f i c i e n t t i m e f o r t h e f o o d o r n u t r i e n t t o be c o n v e r t e d i n t o o r g a n i s m b i o m a s s , t h e n h a r v e s t i n g t h e o r g a n i s m . P e r i o d i c mode r e f e r s t o i n o c u l a t i n g a v e s s e l w i t h t h e o r g a n i s m a n d i t s n u t r i e n t s o u r c e , t h e n p e r i o d i c a l l y h a r v e s t i n g a p o r t i o n o f t h e c u l t u r e w h i l e p e r i o d i c a l l y a d d i n g f r e s h n u t r i e n t o r f o o d . C o n t i n u o u s mood i s t h e same a s p e r i o d i c i n t h e p r e c e d i n g 101 sentence except t h a t p a r t i a l h a r v e s t and f e e d i n g occur c o n t i n u o u s l y i n s t e a d of p e r i o d i c a l l y . An i m p o r t a n t p o i n t i n c o n t i n u o u s or p e r i o d i c c u l t u r e i s t h a t the h a r v e s t r a t e cannot be a l l o w e d t o exceed the i n t e r n a l r e c r u i t m e n t r a t e or the p o p u l a t i o n w i l l not be a b l e t o s u s t a i n as h i g h a l e v e l of p r o d u c t i o n . b. P r i m a r y P r o d u c e r s Under 'primary p r o d u c e r s ' , f o r the purpose o f f t h i s paper, we s h a l l d e f i n e two subgroups. The ' a l g a e ' group w i l l be p r i m a r y p r o d u c i n g p h o t o t r o p h s , who d e r i v e most of t h e i r energy from l i g h t , and the ' b a c t e r i a ' group w i l l i n c l u d e chemotrophic and h e t e r o t r o p h i c b a c t e r i a and f u n g i who get t h e i r energy from i n o r g a n i c and o r g a n i c c h e m i c a l s o u r c e s . A l g a l growth i s dependent upon the a v a i l a b i l i t y of l i g h t , d i s s o l v e d carbon d i o x i d e , n i t r o g e n (as n i t r a t e ) , phosphorus (as phosphate) ( D a v i s and U k e l e s , 1961; Fogg, 1965), and o t h e r n u t r i e n t s i n m i c r o amounts (Goldman, 1972) as w e l l as on the temperature of the c u l t u r e medium. C o n t a i n e r s f o r a l g a l growth s h o u l d t h e r e f o r e g e n e r a l l y have a l a r g e s u r f a c e area t o depth r a t i o f o r l i g h t p e n e t r a t i o n and gas exchange ( L o o s a n o f f , 1951; S t e n g e l , 1970). Temperature i s i d e a l l y kept c o n s t a n t l y warm below the l e t h a l range. For a l g a l c u l t u r e s s o l a r energy i s best used t o keep t e m p e r a t u r e s up, the h i g h s p e c i f i c heat of water m a i n t a i n i n g t e m p e r a t u r e s a t n i g h t . N u t r i e n t s s h o u l d be l o a d e d g r e a t e r than immediate r e q u i r e m e n t s but not e x c e s s i v e l y , s i n c e almost any c h e m i c a l w i l l become t o x i c i f i t s c o n c e n t r a t i o n 1 02 becomes too h i g h (Goldman, 1976a). D i f f e r e n t n u t r i e n t mixes a l s o l e a d t o d i f f e r e n t n u t r i t i o n a l c o m p o s i t i o n of the a l g a e ( R i c h a r d s o n , et a l . , 1969; Spoehr and M i l n e r , 1949). D i f f e r e n t i n o c u l a t i o n forms may l e a d t o changes i n o v e r a l l y i e l d (Boyd e t a l . , 1981). B a c t e r i a l growth i s dependent upon the medium temperature and the abundance and ty p e s of a v a i l a b l e c h e m i c a l energy. Some b a c t e r i a r e q u i r e oxygen, o t h e r s r e q u i r e complete a n o x i a . C o n t a i n e r s f o r b a c t e r i a l c u l t u r e can be any shape because s u n l i g h t i s not used, but a n a e r o b i c v e s s e l s s h o u l d have l i m i t e d gas exchange s u r f a c e s and v i c e v e r s a f o r a e r o b i c c u l t u r e s . Combined a l g a l / b a c t e r i a l c u l t u r e s (Oswald and Golueke, 1968), p a r t i c u l a r l y i n waste water, take advantage of the c a t a b o l i c p r o p e r t i e s of the b a c t e r i a and the p h o t o s y n t h e t i c p r o p e r t i e s of the a l g a e . The n u t r i e n t medium f o r p r i m a r y p r o d u c t i o n c u l t u r e can be p r e s e n t e d t o the organisms d i r e c t l y , as c h e m i c a l or o r g a n i c f e r t i l i z e r added d i r e c t l y t o the c u l t u r e v e s s e l , or i t can be i n f u s e d i n a s e p a r a t e v e s s e l a f t e r s h r e d d i n g or p u l v e r i z i n g and then added t o the c u l t u r e as needed. D i f f e r e n t a n i m a l wastes have d i f f e r e n t c h e m i c a l c o m p o s i t i o n s ( B u l l e y , 1977) and would t h e r e f o r e produce d i f f e r e n t n u t r i e n t l o a d i n g s . Growth r a t e s of both a l g a e and b a c t e r i a a re e x p o n e n t i a l w i t h i n a v e r y s m a l l time s c a l e , as l o n g as the b i o l o g i c a l r e q u i r e m e n t s a r e kept a t an o p t i m a l l e v e l . A l g a l c u l t u r e s i n h i g h n u t r i e n t environments o f t e n bloom so e x t e n s i v e l y t h a t they d e s t r o y themselves by e i t h e r c u t t i n g out the l i g h t or u s i n g up 1 03 a l l the n u t r i e n t s and s t a r v i n g , the r e s u l t i n g massive decay c a u s i n g a n o x i c c o n d i t i o n s t o d e v e l o p ( V a l l e n t y n e , 1974). P r i m a r y p r o d u c t i o n can be m o n i t o r e d f o l l o w i n g the methods o u t l i n e d i n S t e i n (1973) and V o l l e n w e i d e r (1974). c. Secondary P r o d u c e r s We d e f i n e secondary p r o d u c e r s , i n t h i s paper, as b e i n g t h o s e s m a l l a q u a t i c i n v e r t e b r a t e s which would be a c c e p t a b l e as food items f o r f i s h . For c u l t u r i n g p u r p o s e s , the most e f f i c i e n t energy c o n v e r t o r s are the h e r b i v o r o u s or omnivorous p l a n k t o n ( d r i f t f e e d e r s ) and benthos (bottom f e e d e r s ) which r e q u i r e a s h o r t e r food c h a i n than do c a r n i v o r o u s a n i m a l s . The group i n c l u d e s a l l the l i f e s t a g e s of a q u a t i c a n i m a l s such as c r u s t a c e a n s and h e l m i n t h e s as w e l l as a q u a t i c l a r v a e of i n s e c t s or a m p h i b i a . The b i o e n g i n e e r i n g c r i t e r i a f o r d e s i g n i n g a s u i t a b l e c u l t u r e environment f o r a q u a t i c i n v e r t e b r a t e s i n c l u d e an u n d e r s t a n d i n g of the complete l i f e h i s t o r y of the a n i m a l , p l u s d e t e r m i n a t i o n of optimum growing temperature and d e n s i t y , oxygen demand, l i g h t c o n c e n t r a t i o n p r e f e r e n c e (photo-phobic or p h o t o - p h i l i c ) , and p r e f e r r e d food t y p e . Lawrence (1981), I v l e v a (1973) and G a l t s o f f and Needham (1959) have p r e s e n t e d compendia of s m a l l s c a l e c u l t u r e methods f o r a l l t y p e s of i n v e r t e b r a t e s . Some organisms a r e p a r t h e n o g e n i c ( r o t i f e r s , c l a d o c e r a n s ) and t h e i r p o p u l a t i o n s can i n c r e a s e v e r y r a p i d l y ( almost d o u b l i n g each day) a f t e r the i n i t i a l c u l t u r e i n o c u l a t i o n . Others reproduce s e x u a l l y and the speed of p o p u l a t i o n growth i s 1 04 l i m i t e d by the p e r i o d i c i t y of brood p r o d u c t i o n . Copepods can r e l e a s e broods every few weeks and can m u l t i p l y as f a s t as p a r t h e n o g e n i c s p e c i e s , but most i n s e c t s have o n l y one or two broods per y e a r , and t h e r e f o r e have an upper l i m i t of biomass p r o d u c t i o n . Growth r a t e and oxygen demand i n c r e a s e as t e m p e r a t u r e i n c r e a s e s but a l l a n i m a l s have an upper temperature l i m i t where, even i n w e l l a e r a t e d water, temperature s t r e s s r e t a r d s development and growth. S p e c i e s a r e g e n e r a l l y c l a s s i f i e d as c o l d s t e n o t h e r m a l , warm s t e n o t h e r m a l or e u r y t h e r m a l , a c c o r d i n g t o t h e i r t o l e r a n c e of o n l y c o l d water, warm water, or b o t h , r e s p e c t i v e l y , but an o p t i m a l u n s t r e s s f u l growth temperature e x i s t s somewhere w i t h i n t h o s e ranges f o r each s p e c i e s . Photo-phobia or - p h i l i a , and t h e i r subsequent e f f e c t on f e e d i n g and growth r a t e s , stem from the n a t u r a l h a b i t a t t o which the a n i m a l i s adapted, but o f t e n some c o n d i t i o n i n g or d e s e n s i t i z a t i o n may occur i n d o m e s t i c a t e d s t r a i n s s i n c e the p r e d a t o r or prey motive i n f l u e n c e i s no l o n g e r p r e s e n t . Food p r e f e r e n c e i s r e l a t e d t o e d i b i l i t y , d i g e s t i b i l i t y and n a t u r a l a d a p t a t i o n . The a n i m a l s we c o n s i d e r as secondary p r o d u c e r s most l i k e l y f e e d p r i m a r i l y on the p r i m a r y p r o d u c e r s mentioned i n the p r e v i o u s s e c t i o n . Even d e t r i t u s f e e d e r s who a r e found chewing on c h i p s of wood et c e t e r a i n streams and l a k e s g a i n the b u l k of t h e i r sustenance from s c r a p i n g o f f the e p i p h y t i c b a c t e r i a and a l g a e and not from the c e l l u l o s e f i b r e s . ( N e i l l , W. 1978, p e r s . comm.) C u l t u r e v e s s e l s f o r p l a n k t o n i c a n i m a l s s h o u l d have as much volume as p o s s i b l e , thus a h i g h depth t o s u r f a c e a r e a r a t i o . 1 05 Many s u i t a b l e c o n f i g u r a t i o n s a r e diagrammed i n Anraku (1973). V e s s e l s f o r b e n t h i c c u l t u r e need more bottom s u r f a c e a r e a and a r e p r o b a b l y b e s t s h a l l o w , a r r a n g e d i n s t a c k s (as i n K o n s t a n t i n o v , 1973) or deep w i t h s u b s t r a t e s e p t a i n s e r t e d (as i n McLarney, et a l . , 1974). H a r v e s t of p l a n k t o n need o n l y r e q u i r e s i f t i n g or d r a i n i n g the water ( S h a f l a n d e t a l . , 1979) but b e n t h i c organisms must be s e p a r a t e d from t h e i r food s u b s t r a t e (Shaw and Mark, 1980), which i s more d i f f i c u l t i f the s u b s t r a t e p a r t i c l e s a r e the same s i z e or l a r g e r than the a n i m a l s . Both s i z e d i f f e r e n c e s ( S h a f l a n d e t a l . , 1979) and b e h a v i o u r a l response (Erwin and H a i n e s , 1972; Leger and S o o r g e l o o s , 1982), may be used i n h a r v e s t i n g . A n i m a l s which o n l y produce one t o two broods per y e a r , and those which metamorphose from the a q u a t i c s t a g e , are b e t t e r c u l t u r e d i n b a t c h t o t h e i r l a r g e s t p o s s i b l e s i z e b e f o r e b e i n g h a r v e s t e d and s t o r e d f o r use, t o make the most e f f i c i e n t use of t h e i r a q u a t i c growth phase. Q u a n t i f i c a t i o n of i n v e r t e b r a t e p r o d u c t i o n on a l a r g e s c a l e can be t r e a t e d as i n Edmondson and Winberg (1971) f o r w i l d p o p u l a t i o n s , a l t h o u g h the methods a r e somewhat t e d i o u s f o r the r a p i d , c o n t i n u a l needs of commercial c u l t u r e . 106 G. Water Reuse a. J u s t i f i c a t i o n Much a t t e n t i o n has been p a i d t o the o p p o r t u n i t i e s and p r o c e s s e s of water reuse ( a l s o c a l l e d water r e c o n d i t i o n i n g , r e c i r c u l a t i o n or r e c y c l i n g ) i n the pa s t s e v e r a l y e a r s (Anon, 1974; Tiews, 1981). The main reason f o r t h i s i s t h a t c o n s i d e r a b l e e f f o r t (and c o s t ) i s o f t e n expended t o get water w i t h optimum c h a r a c t e r i s t i c s f o r f i s h h e a l t h and growth and, even though f i s h p o l l u t e the water, i t may be cheaper t o t r e a t the p o l l u t i o n than t o p r o v i d e new, o p t i m a l water ( M u i r , 1976). P o t e n t i a l uses f o r r e c y c l i n g systems f a l l i n t o t h r e e c a t e g o r i e s : i ) t o r e c y c l e water: water may be i n s h o r t s u p p l y e i t h e r due t o poor q u a l i t y or t o a l i m i t e d y i e l d s o u r c e . R e c y c l i n g may be an econo m i c a l a l t e r n a t i v e t o f i l t e r i n g l a r g e amounts of d i r t y source water. More f i s h c o u l d be r e a r e d i n a s m a l l f l o w i f i t were reused s e v e r a l times than i f i t were a s i n g l e pass system. i i ) t o r e c y c l e h e a t : h e a t i n g water i s such an e x p e n s i v e p r o p o s i t i o n t h a t every means s h o u l d be employed not t o waste t h a t heat once i t i s g e n e r a t e d . Water r e u s e , a l o n g w i t h heat exchangers and heat pumps ( I n t e r n a t i o n a l Energy Agency, 1982), i s one way of keeping most of the heat i n s i d e the system. i i i ) t o r e c y c l e c h e m i c a l s : f i s h c u l t u r e o f t e n r e q u i r e s the a d d i t i o n of t r e a t m e n t d r u g s , hormones or i o n s t o the 1 07 p r o c e s s water t o improve the h e a l t h and growth of the f i s h . As l o n g as the c h e m i c a l s are c o m p a t i b l e w i t h the t r e a t m e n t systems b e i n g used, r e c y c l i n g can d r a s t i c a l l y c u t down on the amounts of i n p u t c h e m i c a l s needed. The p r o c e s s of r e c y c l i n g i n v o l v e s m a i n l y f i l t e r i n g out of t o x i c s o l i d and d i s s o l v e d waste p r o d u c t s and r e i n t r o . d u c t i o n of oxygen. b. P h y s i c a l - C h e m i c a l F i l t r a t i o n P h y s i c a l f i l t r a t i o n i n v o l v e s the removal of suspended p a r t i c l e s from the water, u s u a l l y done w i t h a p e r t u r e f i l t e r s , s e t t l i n g ponds or a c o m b i n a t i o n of the two. The i m p o r t a n t parameters a r e the comparison between the s i z e of the p a r t i c l e s and the a p e r t u r e s i z e and on the s e t t l i n g r a t e and the s e t t l i n g pond r e s i d e n c e t i m e . A p e r t u r e f i l t e r s may be s c r e e n s ( f i x e d or r o t a t i n g ) or boxes f i l l e d w i t h f i l t e r medium (sand, g r a v e l , koch r i n g s , e t c .) . Chemical f i l t r a t i o n u s u a l l y i n v o l v e s the a d d i t i o n of c e r t a i n c h e m i c a l s t o p r e c i p i t a t e or a l t e r the t o x i c m e t a b o l i t e s i n the w a t e r . T h i s can be done t h r o u g h pH changes ( i . e . o y s t e r s h e l l s ) , a b s o r p t i o n ( i . e . a c t i v a t e d c a r b o n ) , c a t a l y s i s , e m u l s i f i c a t i o n or bubble f l o c u l a t i o n ( S p o t t e , 1979; Wheaton, 1977). Water s t e r i l i z a t i o n or d i s i n f e c t i o n , the d e s t r u c t i o n of p o t e n t i a l pathogens or t h e i r v e c t o r s , i s u s u a l l y a c c o m p l i s h e d t h r o u g h c h e m i c a l or p h y s i c a l means. The two most w i d e l y used 1 08 methods i n f i s h c u l t u r e a r e r a d i a t i o n w i t h u l t r a v i o l e t l i g h t and o z o n a t i o n . C h l o r i n a t i o n i s a l s o used, however, c a r e must be taken s i n c e c h l o r i n e ( i n c o m b i n a t i o n w i t h ammonia) can be h i g h l y t o x i c t o f i s h as w e l l as t o pathogens (Wheaton, 1977). c. B i o l o g i c a l F i l t r a t i o n The main aim of b i o l o g i c a l f i l t r a t i o n i s t o d e t o x i f y n i t r o g e n o u s wastes, p a r t i c u l a r l y ammonia, by o x i d i z i n g i t , v i a b a c t e r i a l c u l t u r e , t o n i t r a t e , a n o n - t o x i c s u b s t a n c e . The b a c t e r i a l c u l t u r e s a l s o tend t o absorb many o t h e r s u b s t a n c e s from the water i n the p r o c e s s of d e t o x i f i c a t i o n , g e n e r a l l y a c t i n g as an a c c e l e r a t e d n a t u r a l r e c o n d i t i o n i n g system. B i o l o g i c a l f i l t e r s a r e u s u a l l y combined i n the same c o n t a i n e r w i t h a p h y s i c a l a p e r a t u r e f i l t e r , the medium a l s o b e i n g the s u b s t r a t e t o which the b a c t e r i a a re a t t a c h e d . The water r e s i d e n c e time and v e l o c i t y t h r o u g h the f i l t e r , as w e l l as the p a r t i c l e s i z e of the f i l t r a t e medium, a r e i m p o r t a n t i n d e t e r m i n i n g the e f f e c t i v e n e s s of the b a c t e r i a l c o n v e r s i o n . B i o l o g i c a l f i l t e r s need t o be p r i m e d , by a l l o w i n g some time f o r the b a c t e r i a l p o p u l a t i o n t o d e v e l o p a t a moderate l e v e l of n u t r i e n t l o a d i n g . The s i z e of the f i l t e r r e q u i r e d f o r a p a r t i c u l a r s i z e of f i s h c u l t u r e system and l e v e l of r e c y c l i n g can be d e t e r m i n e d from W i l l o u g h b y ' s (1968) or Hirayama's (1974) e q u a t i o n s f o r c a l c u l a t i n g c a r r y i n g c a p a c i t i e s . W i l l o u g h b y ' s e q u a t i o n c a l c u l a t e s the maximum amount of food t h a t can be f e d per day, from which the a p p r o p r i a t e number of f i s h i s back-c a l c u l a t e d . H i s assumptions (from H a s k e l l , 1959) a r e t h a t f i s h 109 l o a d i n g l e v e l s a re l i m i t e d by oxygen consumption and m e t a b o l i t e a c c u m u l a t i o n , which a r e both p r o p o r t i o n a l t o the amount of food ( o x i d i s a b l e biomass) e n t e r i n g the system. where: Oa = i n f l u e n t c o n c e n t r a t i o n of oxygen ( i n ppm), Ob = e f f l u e n t oxygen c o n c e n t r a t i o n , or 5 ppm, the low e s t t h r e s h o l d f o r t r o u t , 5.45 = m e t r i c t o ns of water i n 1 g a l l o n per minute f o r one day, 100 = grams of oxygen t o m e t a b o l i z e 1,200 c a l o r i e s (1 l b . ) of t r o u t p e l l e t s , gpm = f l o w r a t e of incoming water. T h i s e q u a t i o n does not take i n t o account the a c c u m u l a t i o n of m e t a b o l i t e s i n r e c y c l i n g systems, which must be i n v e s t i g a t e d t o d e termine when h i g h ammonia l e v e l s r e p l a c e low oxygen c o n c e n t r a t i o n s as the l i m i t i n g f a c t o r . From s t u d i e s done on t r o p i c a l aquarium f i s h e s , Hiramaya (1974) d e v e l o p e d an e x p r e s s i o n t o r e p r e s e n t the p o l l u t i o n c r e a t e d by f i s h r e s p i r a t i o n and a matching e x p r e s s i o n f o r the abatement of f i s h p o l l u t i o n by a b i o l o g i c a l f i l t e r . The system d e s i g n or o p e r a t i n g parameters a r e a d j u s t e d such t h a t the p o l l u t i o n does not exceed the f i l t e r c a p a c i t y . Food per day = (Oa-Ob) * 5.45/100 * gpm (11) 1 ow (B**[0.544]/100) + 0.51F 0.70 + 950 (12) V i G+D where: B = weight per f i s h (gm) W f i l t e r s u r f a c e a r e a (m 2) F = d a i l y food (gm) V i f i l t e r v e l o c i t y (cm/min) q = no. f i s h i n system D f i l t e r depth p = no. of f i l t e r s G g r a v e l c o e f f i c i e n t {=X/R} 1 10 R = mean g r a i n s i z e X = p e r c e n t weight of f r a c t i o n S p o t t e (1979) recommended t h a t , s i n c e b a c t e r i a need s u r f a c e a r e a f o r attachment t o the s u b s t r a t e and s i n c e most of the b i o l o g i c a l a c t i v i t y i s c o n c e n t r a t e d i n the upper l a y e r s , f i l t e r s s h o u l d be d e s i g n e d f o r a l a r g e s u r f a c e t o depth r a t i o , u s i n g s m a l l , a n g u l a r g r a v e l (2 t o 5 mm d i a m e t e r — s m a l l e r s i z e s tend t o c l o g ) . Speece (1973) dev e l o p e d an o r d e r l y and easy t o use g r a p h i c a l d e s i g n p r o c e d u r e f o r b i o l o g i c a l f i l t e r s based on the p r e v i o u s p u b l i s h e d r e l a t i o n s h i p s of many a u t h o r s . L i a o and Mayo (1974) a l s o worked up d e s i g n c r i t e r i a but d i d not make a t a l l c l e a r how they were t o be used. d. A e r a t i o n A major s t e p i n r e c o n d i t i o n i n g water i s t o r e p l e n i s h the oxygen c o n c e n t r a t i o n and t o get r i d of o t h e r e x c e s s or t o x i c gases (carbon d i o x i d e , ammonia, n i t r o g e n , ozone, c h l o r i n e ) . A e r a t i o n ( a l s o d i f f e r e n t l y d e f i n e d as d e g a s s i n g , s t r i p p i n g , o x y g e n a t i o n , r e a e r a t i o n ) e f f i c i e n c y depends both on the c h e m i c a l ( i o n i c s t a t e , s o l u b i l i t y ) and p h y s i c a l ( c o n c e n t r a t i o n s , t emperature a c t i v e exchange area) c h a r a c t e r i s t i c s of the system. The d i f f e r e m c e i n c o n c e n t r a t i o n between the maximum s o l u b l e c o n c e n t r a t i o n (100% s a t u r a t i o n , Cs) at a c e r t a i n temperature of water and the a c t u a l c o n c e n t r a t i o n of t h a t gas found (C) are the d r i v i n g v a r i a b l e s i n the mass t r a n s f e r e q u a t i o n (from Sowerbutts and F o r s t e r , 1981). R = kL(Cs-C) (13) 111 where: R = the r a t e of gas t r a n s f e r per u n i t of t r a n s f e r a r e a and kL = the a e r a t i o n c o e f f i c i e n t f o r a p a r t i c u l a r s e t of c o n d i t i o n s . The e q u i l i b r i u m c o n c e n t r a t i o n of oxygen ( i n mg/1, termed s a t u r a t i o n ) depends on temperature and b a r o m e t r i c p r e s s u r e (McLean and Boreham, 1980). The h i g h e r the oxygen c o n c e n t r a t i o n ( c l o s e r t o s a t u r a t i o n ) , the more f i s h can be r e a r e d per u n i t of water. Water oxygenates q u i t e q u i c k l y because t h e r e i s l o t s of oxygen a v a i l a b l e i n the a i r (20% or 20,000 ppm) compared t o the s a t u r a t i o n of oxygen i n water (about 10 ppm a t 15°C at sea l e v e l ) . The pH of the water d e t e r m i n e s the n o n - i o n i z e d ( a v a i l a b l e ) f r a c t i o n s of carbon d i o x i d e and ammonia. C h l o r i n e and ozone a r e e a s i l y s t r i p p e d from water. N i t r o g e n gas, however, i s v e r y abundant i n a i r (80,000 ppm) compared t o i t s s o l u b i l i t y i n water (16 ppm) and t h e r e f o r e t a k e s some e f f o r t t o s t r i p o u t . S u p e r s a t u r a t e d n i t r o g e n i s common i n both s u r f a c e and ground waters and has been l i n k e d t o s e v e r a l d i s e a s e problems (Owsley, 1981). S e v e r a l a e r a t o r t y p e s a r e a v a i l a b l e ( S o w e r b u t t s and F o r s t e r , 1981): 1. S u r f a c e s p r a y e r s - spray i n t o a i r 2. A g i t a t o r s - paddle wheels, p r o p e l l e r s t o move water 3. V e n t u r i s - suck a i r t o s u p p l y l i n e 4. I m p i n g i n g j e t s - f o r c e a i r / w a t e r mix i n t o water 5. U-tube - bubble a i r i n t o s u p p l y l i n e 6. D i f f u s e d a i r - bubble a i r i n t o c u l t u r e c o n t a i n e r 7. Cascades - s p l a s h a i r down s t e p s or th r o u g h medium 1 12 The dilemma i s t o add oxygen w h i l e not a t the same time a d d i n g n i t r o g e n . A l l the t y p e s of a e r a t o r s l i s t e d , except the l a s t , use h i g h p r e s s u r e a t some p o i n t and t h e r e f o r e run the r i s k of p r o d u c i n g s u p e r s a t u r a t e d n i t r o g e n c o n c e n t r a t i o n s . McLean and Boreham (1980) d e v e l o p e d a s i m p l e model which p r e d i c t s f i n a l gas c o n c e n t r a t i o n (as per c e n t s a t u r a t i o n , X) i n a cascade s c r e e n type a e r a t o r : X = 100 - (100-X 0) * e x p ( - 0 . 2 2 l 8 * JcT * ks * n) (14) where: X° = i n i t i a l gas c o n c e n t r a t i o n ( % s a t u r a t i o n ) , n = number of s c r e e n s , d = d i s t a n c e i n cm between s c r e e n s , and ks = a e r a t i o n c o n s t a n t d e r i v e d on a per s c r e e n b a s i s f o r 8 i n c h s p a c i n g between s c r e e n s . The u t i l i t y of t h i s model i s i n p r e d i c t i n g how many s c r e e n s , or packed column segments, are r e q u i r e d t o r e a e r a t e o x y g e n - d e p l e t e d water back t o the 95% r e q u i r e d f o r the i n f l o w t o r e a r i n g c o n t a i n e r s . Because the d i f f e r e n c e between Cs and C ( i n E q u a t i o n 13 or 100 and X° i n E q u a t i o n 14) d e c r e a s e s as a e r a t i o n o c c u r s , the r a t e of a e r a t i o n a l s o d e c r e a s e s , t h e r e f o r e i t i s v e r y d i f f i c u l t t o r e a c h 100% s a t u r a t i o n w i t h o u t employing above ambient p r e s s u r e s , which would a l s o r a i s e n i t r o g e n p r e s s u r e s . T h i s model has been d e v e l o p e d f u r t h e r by the Department of F i s h e r i e s and Oceans s t a f f ( u n p u b l i s h e d ) i n t o a computer model which p r e d i c t s the a e r a t i o n e f f e c t (change i n p e r c e n t s a t u r a t i o n ) g i v e n the system c o n f i g u r a t i o n and a e r a t i o n c o n s t a n t ( d e r i v e d from numerous t e s t s ) . 1 1 3 e. R e c y c l i n g Systems T o t a l water r e c o n d i t i o n i n g systems u s u a l l y i n c l u d e a c o m b i n a t i o n of p h y s i c a l f i l t r a t i o n w i t h c h e m i c a l , b i o l o g i c a l or both c h e m i c a l and b i o l o g i c a l f i l t r a t i o n , p l u s d i s i n f e c i o n and a e r a t i o n ( L i a o and Mayo, 1972; Meade, 1974). Very s i m p l e systems (Godyn, 1977) may get by w i t h b i o l o g i c a l ( i n c o r p o r a t i n g p h y s i c a l ) f i l t r a t i o n and a e r a t i o n i n homemade c o n t a i n e r s . L a r g e r o p e r a t i o n s can i n v o l v e some complex plumbing f o r f i l t e r backwash (Burrows and Combs, 1968). A l a r g e investment i n water reuse systems i s the pumping system w i t h f a i l - s a f e emergency backup pumps or a l t e r n a t e power s u p p l y . MacDonald, e t a l . (1975) g i v e s a p r o d u c t i o n c o s t a n a l y s i s of a p a r t i c u l a r system and Mayo (1971) g i v e s an example c o s t i n g of energy i n t e n s i v e r e u s e . U s i n g a s e r i a l r e c y c l i n g system i n a r e a s where p l e n t y of d i s t a n c e i s a v a i l a b l e down a s l o p e , l e t t i n g g r a v i t y t a k e the water from one pond t o a n o t h e r , i s an a l t e r n a t i v e t o pump powered r e u s e . Most commercial farms use t h i s t e c h n i q u e t o a l i m i t e d e x t e n t but water r e c o n d i t i o n between ponds i s u s u a l l y m i n i m a l . 1 14 H. Water C o n t r o l and Measurement a. I n t r o d u c t i o n Any f a c i l i t y which wishes t o make o p t i m a l use of the water r e s o u r c e a v a i l a b l e t o i t must i n c o r p o r a t e i n t o i t s d e s i g n mechanisms and methods f o r the measurement and c o n t r o l of water d i s t r i b u t i o n and water c h a r a c t e r i s t i c s . M o n i t o r i n g w i l l a i d i n the maintenance of a q u a l i t y o p e r a t i o n through comparison w i t h 'known' v a l u e s f o r s t o c k i n g d e n s i t y per l i t e r per minute and flow v e l o c i t i e s f o r raceway s e l f c l e a n i n g and f i s h p r e f e r e n c e . C o n t r o l of water f l o w i s n e c e s s a r y both t o m a i n t a i n a t l e a s t minimum water q u a l i t y v a l u e s as w e l l as t o c o n s e r v e use of the water r e s o u r c e . C o n t r o l of p h y s i c a l / c h e m i c a l parameters w i l l h e l p keep the o p e r a t i n g c o n d i t i o n s as near optimum 'as p o s s i b l e . The type of the measurement c o n t r o l d e v i c e used depends on the water s o u r c e , the conveyance used and the needs of the o p e r a t i o n . Sources can be s u r f a c e ( l a k e , stream) or a q u i f e r ( s p r i n g , w e l l ) . Conveyances are c a t e g o r i z e d , f o r e n g i n e e r i n g p u r p o s e s , as open c h a n n e l or c o n d u i t t y p e . A p a r t i a l l y f i l l e d c o n d u i t i s c o n s i d e r e d as an open c h a n n e l . The f l o w r e q u i r e m e n t s of the p o s t - c o n t r o l water system r e l a t e t o a s l o w l y i n c r e a s i n g c o n s t a n t need, dependent on the system d e s i g n and b i o l o g i c a l r e q u i r e m e n t s of the c u l t u r e d o r g a n i s m s , but the p r e - c o n t r o l c o n d i t i o n s may i n c l u d e h a n d l i n g g r e a t f l u c t u a t i o n s i n n a t u r a l f l o w , from v e r y h i g h f l o w i n s p r i n g , when f a c i l i t y needs a r e low, t o v e r y low water a v a i l a b i l i t y i n l a t e summer, when f a c i l i t y needs a r e h i g h . P h y s i c a l / c h e m i c a l c o n t r o l d e v i c e s a r e 1 1 5 much more energy consumptive than f l o w c o n t r o l s , wastage depending on i n p u t s v e r s u s r e u s e . b. Flow Measurement Three t y p e s of water measurement d e v i c e s a r e used i n open ch a n n e l conveyances. The d e s i g n and c o n s t r u c t i o n of these d e v i c e s , w i t h subsequent c a l i b r a t i o n and r e a d i n g , have been f u l l y c o d i f i e d due m a i n l y t o e x t e n s i v e use i n i r r i g a t i o n c o n t r o l systems a l l over the w o r l d (Bureau of R e c l a m a t i o n s , 1975). The s i m p l e s t d e v i c e i s the 'V n o t c h w e i r , f o l l o w e d by the P a r s h a l l flume and the submerged o r i f i c e . Flow measurement i n c o n d u i t s i s u s u a l l y measured by the p r i n c i p l e of p r e s s u r e d i f f e r e n c e s on o p p o s i t e s i d e s of changes i n the p i p e shape. The p r e s s u r e d i f f e r e n c e s a r e made v i s i b l e u s i n g manometers s e t i n f r o n t of s c a l e s , such t h a t the d i f f e r e n c e i n p r e s s u r e head can be c a l c u l a t e d (Wheaton, 1977). The changes i n p i p e shape i n c l u d e the v e n t u r i , the p l a t e o r i f i c e , change i n p i p e d i a m e t e r or n i n e t y degree elbow. A l l of t h e s e shape changes cause p r e d i c t a b l e s t a t i c head l o s s or g a i n but the mathematics a r e v e r y complex and each i n d i v i d u a l d e v i c e i s u s u a l l y c a l i b r a t e d f o r g r e a t e r a c c u r a c y . Another f l u i d measurement d e v i c e more o f t e n used i n the measurement of gaseous than l i q u i d f l u i d f l o w , because of f o u l i n g problems, i s the r o t a m e t e r , o p e r a t i n g on the p r i n c i p l e of p r e s s u r e e x e r t e d on a known weight of known shape i n a known diameter p i p e . Rotameters, as most c o n d u i t f l o w measurement d e v i c e s , can be bought a l r e a d y c a l i b r a t e d f o r the range of f l o w expected i n the 1 16 p a r t i c u l a r p i p e s i z e t o be used. c. Flow C o n t r o l The purpose of f l o w c o n t r o l d e v i c e s i s t o i n s u r e a c o n s t a n t downstream f l o w , r e g a r d l e s s of the upstream c o n d i t i o n s . Most commonly downstream flow i s r e g u l a t e d a t a c o m b i n a t i o n measurement/fixed c o n t r o l d e v i c e , such as a w e i r or g a t e , by p e r i o d i c manual adjustment of the w e i r h e i g h t or gate opening t o accomodate changes i n the measured f l o w due t o c h a n g i n g upstream c o n d i t i o n s . T h i s method can be q u i t e s u f f i c i e n t f o r o p e r a t i o n s which expect s m a l l , slow changes i n upstream c o n d i t i o n s , and, w i t h an a d j u s t a b l e emergency o v e r f l o w from the c o n t r o l l e d r e s e r v o i r , may accomodate more d r a s t i c upstream f l o w changes. For more a c c u r a t e and c o n s t a n t c o n t r o l , c o n s t a n t head boxes or r e g u l a t o r s a r e used. The c o n s t a n t head box i s a s m a l l r e s e r v o i r which i s always kept f u l l t o over f l o w i n g , such t h a t a c o n s t a n t head i s m a i n t a i n e d , thus a c o n s t a n t o u t f l o w p r e s s u r e , w h i c h , w i t h c r o s s s e c t i o n a l a r e a and p i p e f r i c t i o n , d e t e r m i n e s f l o w . The r e g u l a t o r m a i n t a i n s a c o n s t a n t o u t f l o w p r e s s u r e t h r o u g h the use of diaphragms. Pond l e v e l s can be c o n t r o l l e d w i t h s t a n d p i p e s or s t o p l o g s ( F i g u r e 11). V a r i a b l e c o n t r o l pumps can be used t o c o n t r o l water f l o w r a t e s i n well-pumped and r e c y c l i n g systems. The pump output can be m e c h a n i c a l l y c a l c u l a t e d from r e v o l u t i o n s per minute (r.p.m.) and c o n t r o l l e d v i a a governor or can be c o n t r o l l e d from an e l e c t r i c a l feed-back from a f l o w measurement d e v i c e . 1 18 d. Temperature C o n t r o l The p h y s i c a l parameter most v i t a l t o a q u a c u l t u r a l o p e r a t i o n s , o u t s i d e of oxygen c o n c e n t r a t i o n which was c o v e r e d under A e r a t i o n i n the p r e v i o u s s e c t i o n , i s water t e m p e r a t u r e . Due t o the h i g h s p e c i f i c heat of water, r a i s i n g or l o w e r i n g water temperatures t h r o u g h f u r n a c e h e a t i n g or r e f r i g e r a t i o n i s v e r y energy consumptive and thus e x p e n s i v e . Water temperature can o f t e n be p a r t i a l l y c o n t r o l l e d t h r ough s e l e c t i o n of the p r o p e r water source and through use of s o l a r h e a t i n g , i n s u l a t i o n or s h a d i n g t o r a i s e or m a i n t a i n t e m p e r a t u r e s of water i n t r a n s i t . Hay (1979) g i v e s a s t r a i g h t f o r w a r d method of c a l c u l a t i n g s o l a r h e a t i n g p o t e n t i a l w i t h i n p u t d a t a f o r a number of l o c a t i o n s i n B. C. H i s approach i s t h a t of s i m p l e energy b a l a n c e . The Energy R e q u i r e d i s the p r o d u c t of the mass heated ( f l o w times the time p e r i o d ) , the t h e r m a l c a p a c i t y of the substance b e i n g heated and the d i f f e r e n c e i n temperature needed. The Energy A v a i l a b l e i s the p r o d u c t of the i n c i d e n t r a d i a t i o n per u n i t a r e a , the s i z e of c o l l e c t o r , the e f f i c i e n c y of the c o l l e c t o r and the time p e r i o d of exposure. Energy A v a i l a b l e depends on c o l l e c t o r c h a r a c t e r i s t i c s ( a s p e c t , s l o p e , t y p e , e t c . ) , the g e o g r a p h i c l o c a t i o n and the time of y e a r . Deep a q u i f e r t e m p e r a t u r e s o f t e n r e f l e c t the mean annual ambient a i r temperature of the r e g i o n (Buss and M i l l e r , 1971) and t h u s can a f f o r d a warmer water s u p p l y i n w i n t e r and a c o l d e r s u p p l y i n summer than s u r f a c e s o u r c e s . Stream t e m p e r a t u r e s most n e a r l y r e f l e c t the ambient a i r t e m p e r a t u r e s , u s u a l l y w i t h some time 1 1 9 l a g f o r change, a l t h o u g h the source of the stream water ( r a i n r u n o f f v e r s u s snowmelt) and the l e n g t h and sh a d i n g of the stream make f o r g r e a t i n c o n s i s t e n c i e s . Lake water temperature i s most c l o s e l y r e l a t e d t o season and i n t e r n a l m i x i n g . A t y p i c a l s m a l l , deep temperate l a k e i s w e l l mixed i n the e a r l y summer but becomes s t r a t i f i e d i n the m i d - l a t e summer, w i t h a warm, upper e p i l i m n i o n and a c o l d , lower h y p o l i m n i o n , s e p a r a t e d p h y s i c a l l y by a t h e r m a l d e n s i t y b a r r i e r . A f t e r complete m i x i n g a g a i n i n the f a l l , s t r a t i f i c a t i o n a g a i n s e t s up i n the w i n t e r . T h i s time the upper l a y e r i s c o l d e r than the lower l a y e r , which remains c l o s e t o 4 ° C , the most dense temperature f o r f r e s h water ( W e t z e l , 1975). C h o i c e of o u t l e t depth can t h e r e f o r e d e termine the temperature of the water ( F i g u r e 12). T h i s v a r i a t i o n i n t e m p e r a t u r e s of d i f f e r e n t water s o u r c e s a t d i f f e r e n t t i m e s of the year p r o v i d e s c o n s i d e r a b l e leeway i n c h o o s i n g a s u i t a b l e water s o u r c e temperature f o r an a q u a c u l t u r a l o p e r a t i o n . I f the chosen water s o u r c e i s not warm enough, s o l a r r a d i a t i o n i n conveyance may be used t o warm i t up. I f the water i s to be kept c o l d , s h a d i n g or i n s u l a t i n g the c o n d u i t would h e l p . CROSS-SECTION OF TEMPERATURE CONTROL F i g u r e 12. A n e x a m p l e o f a t e m p e r a t u r e s e l e c t i o n d e v i c e ( f r o m S a l m o n i d F a c t S h e e t #3, F i s h e r i e s a n d M a r i n e S e r v i c e ) . 121 4. MODELLING AQUATIC PRODUCTION A. A p p r o a c h e s t o O r g a n i c Growth The f a c t o r s w h i c h a f f e c t t h e s i z e o f a p o p u l a t i o n a r e r e c r u i t m e n t , g r o w t h , and l o s s e s . R e c r u i t m e n t i n c l u d e s p o p u l a t i o n i n c r e a s e by b i r t h ( h a t c h i n g , m e t a m o r p h o s i s from l a r v a e ) and i m m i g r a t i o n . Growth i s i n c r e a s e d by i n d i v i d u a l b i o m a s s a c c u m u l a t i o n . L o s s e s may be d e a t h t h r o u g h n a t u r a l c a u s e s , p r e d a t i o n o r f i s h i n g , l o s s t h r o u g h r e s p i r a t i o n or may j u s t be e m m i g r a t i o n from t h e a r e a . T h e s e f a c t o r s may be c o n s i d e r e d i n a ' b l a c k box' a r r a n g e m e n t as f o l l o w s : r e c r u i t m e n t -growth-p o p u l a t i o n s i z e • l o s s e s The b l a c k box can be t r e a t e d as an unknown p r o c e s s i n w h i c h c a s e t h e i n p u t s and o u t p u t s a r e summed t o a r r i v e a t t h e p o p u l a t i o n s i z e (Gupta and H o u d e s h e l l , 1973): P 1 = P 2 + R + G - L (15) R = B + I L = M + F + E + C where: P1 = i n i t i a l p o p u l a t i o n , P2 = f i n a l p o p u l a t i o n , R r e c r u i t m e n t , G = g r o w t h , L = l o s s e s , B = b i r t h s , I i m m i g r a t i o n s , M = n a t u r a l m o r t a l i t y , F = f i s h i n g m o r t a l i t y , E = e m m i g r a t i o n , C = c a t a b o l i c l o s s e s . 1 22 T h i s k i n d of summative approach t o m o d e l l i n g the p o p u l a t i o n i s a t b e s t o n l y d e s c r i p t i v e , s i n c e a l l the f a c t o r s must be known beforehand f o r the e q u a t i o n t o b a l a n c e . Such a model i s u s e l e s s i n p r e d i c t i n g the response of the p o p u l a t i o n t o any p e r t u r b a t i o n s i n c u r r e d between d e s c r i p t i v e i n t e r v a l s . Another way t o model a p o p u l a t i o n i s t o experiment w i t h a l l the c o n f i g u r a t i o n s of the d r i v i n g v a r i a b l e s and t a b u l a t e the r e s u l t s . T h i s k i n d of m o d e l l i n g i s the b a s i s of most management d e c i s i o n s i n f i s h c u l t u r e s i t u a t i o n s , where c o n d i t i o n s are m a i n t a i n e d c o n s t a n t from year t o year ( B u t t e r b a u g h and W i l l o u g h b y , 1967; P i p e r , 1970). However, i t i s o n l y v a l i d f o r p r e s e n t l y o p e r a t i n g o p e r a t i o n s or f o r p r e d i c t i n g the output of o p e r a t i o n s which a r e d e s i g n e d i d e n t i c a l t o the m o d e l l e d ones. The t a b u l a r r e f e r e n c e model f a i l s when a p r e v i o u s l y unencountered p e r t u r b a t i o n a f f e c t s the system, or when p r e d i c t i o n s a r e needed f o r systems which d e v i a t e from p r i o r e x p e r i e n c e i n t h e i r d e s i g n or s e t t i n g , and f o r which t h e r e i s no w e l l q u a n t i f i e d t a b u l a t i o n from which t o draw. The t h i r d approach t o o r g a n i c growth i s t o c r e a t e a m a t h e m a t i c a l model which i s a c l o s e a n a l o g y t o e i t h e r the p h y s i c a l p r o c e s s e s i n v o l v e d or mimics the r e s u l t s of t h o s e p r o c e s s e s . S p a i n (1982) l i s t s a number of m a t h e m a t i c a l e x p r e s s i o n s which p r o v i d e c u r v i l i n e a r graphs ( F i g u r e 13). O r g a n i c growth, whether of a p o p u l a t i o n or an i n d i v i d u a l e x h i b i t s an e x p o n e n t i a l phase at some p o i n t when c o n d i t i o n s are met. T h i s has been r e p r e s e n t e d by the e x p o n e n t i a l f u n c t i o n P2 = P1 * exp(Growth Rate) (16) 123 124 T h i s g i v e s a curve which r e p r e s e n t s the i n i t i a l p o r t i o n of a growth c u r v e but ' o r g a n i c ' growth tends t o f o l l o w a more l o g i s t i c form, where growth slows a g a i n as i t approaches the maximum s i z e p o s s i b l e ( G o l d , 1977). The r a t e s i n v o l v e d , t h a t i s the K c o n s t a n t t h a t d e t e r m i n e s which s l o p e i s a p p r o p r i a t e f o r the l o g i s t i c growth c u r v e , can be c o n s i d e r e d as the i n i t i a l a f f e c t i n g components: growth (GL), r e c r u i t m e n t (RL) and l o s s ( L P ) . I f the s e components are c o n s i d e r e d as r a t e s of i n p u t as opposed t o the i n p u t s t h e m s e l v e s , t h e i r summation can d e f i n e the growth c o n s t a n t : dP/dt = RP + GP - LP (17) The next problem i s t o l i n k the v a r i a t i o n i n e n v i r o n m e n t a l parameters t o d i f f e r e n t v a l u e s of d r i v i n g v a r i a b l e s . The growth r a t e 'also i n c r e a s e s l o g i s t i c l y as the growth r e q u i r e m e n t s i n c r e a s e . At some p o i n t the growth r a t e reaches a maximum v a l u e r e g a r d l e s s of c o n t i n u e d i n c r e a s e i n growth r e q u i r e m e n t s . T h i s k i n d of cu r v e v e r y c l o s e l y resembles the r e l a t i o n s h i p between the r a t e of a c t i o n of an enzyme as i t s s u b s t r a t e c o n c e n t r a t i o n i n c r e a s e s . Monod (1942) d e f i n e d such enzyme a c t i v i t y m a t h e m a t i c a l l y as A = Amax * C (18) (C + K) where: A = a c t i v i t y r a t e , Amax = maximum p o s s i b l e a c t i v i t y r a t e when the enzyme system i s s a t u r a t e d w i t h s u b s t r a t e , C s u b s t r a t e c o n c e n t r a t i o n , K = the h a l f s a t u r a t i o n c o n s t a n t f o r t h a t p a r t i c u l a r s u b s t r a t e such t h a t i f C = K, the a c t i v i t y ra-te i s one h a l f of the maximum. M i c h a e l i s and Menton adapted t h i s 125 m a t h e m a t i c a l r e l a t i o n s h i p t o b i o l o g i c a l systems such t h a t P = jumax * S (19) (S + Ks) where: growth r a t e i s r e p r e s e n t e d by ju, maximum growth r a t e by p a x , and Ks i s the h a l f s a t u r a t i o n of S, where S i s the l i m i t i n g f a c t o r i n response t o L e i b i g ' s Law of the Minimum (Boughey, 1971) i n the which the l e a s t abundant n u t r i e n t i s c o n s i d e r e d t o c o n t r o l the growth r a t e of a p o p u l a t i o n or n u t r i e n t . More than one l i m i t i n g f a c t o r , and thus t h e i r i n t e r a c t i o n may be c o n s i d e r e d i n t h i s e q u a t i o n : u = pmax * SI * S2 * Sn (20) (SI + Ks1) (S2 + Ks2) (Sn + Ksn) where: S1, S2...Sn are the c o n c e n t r a t i o n s of d i f f e r e n t n u t r i e n t s and Ks1, Ks2...Ksn a r e the r e s p e c t i v e h a l f s a t u r a t i o n c o n s t a n t s f o r those n u t r i e n t s . The h a l f s a t u r a t i o n c o n s t a n t i s d e r i v e d from e x p e r i m e n t a t i o n w i t h c h e m o s t a t i c a l l y c o n t r o l l e d c o n t i n u o u s c u l t u r e s , whose t e c h n i q u e s and mathematics a r e d e s c r i b e d i n some d e t a i l i n K u b i t s c h e k (1970). The steady s t a t e c o n c e n t r a t i o n of the growth l i m i t i n g n u t r i e n t i n a chemostat w i t h o u t c e l l r e t u r n i s d e s c r i b e d by: SI = Ks(1 / e+Kd (21) ju-( 1/8+Kd) where: S1 = steady s t a t e n u t r i e n t c o n c e n t r a t i o n , 8 = the r e s i d e n c e t i m e , Ks = h a l f s a t u r a t i o n c o n s t a n t , p = maximum s p e c i f i c growth r a t e , and Kd = decay r a t e . To s o l v e f o r Ks, the e q u a t i o n can be w r i t t e n a s : 126 Ks = S1*u (22) (1 / e+Kd)-S1 the Ks v a l u e can be c a l c u l a t e d i f u and Kd a r e known and SI i s de t e r m i n e d f o r a s p e c i f i c 0. Droop (1973) o u t l i n e s a more a c c u r a t e method f o r the c o n s i d e r a t i o n of h a l f s a t u r a t i o n c o n s t a n t s of more than one l i m i t i n g n u t r i e n t s i m u l t a n e o u s l y . The c o n s t a n t s may a l s o be d e r i v e d g r a p h i c a l l y from r e g r e s s i o n s c a l c u l a t e d from graphs of the growth r a t e v e r s u s n u t r i e n t c o n c e n t r a t i o n ( F i g u r e 14). B. Aquat i c Pro d u c t i o n a. F a c t o r s I n v o l v e d D e s c r i p t i o n s of a q u a t i c ecosystems and t h e i r e n v i r o n m e n t a l parameters and d r i v i n g v a r i a b l e s may be found i n many s o u r c e s ( W e t z e l , 1975, Pa r s o n s and T a k a h a s h i , 1973). An e x c e l l e n t r e v i e w of 22 e a r l y a q u a t i c p r o d u c t i o n models i s g i v e n i n P a t t e n (1968). To model any m u l t i - t r o p h i c system we must un d e r s t a n d the b i o l o g i c a l components i n v o l v e d and the p h y s i c a l components which a f f e c t them. The a q u a t i c ecosystem i n v o l v e s the i n t e r p l a y of many f u n c t i o n a l l y d i f f e r e n t t a x a - - a l g a e , b a c t e r i a , z o o p l a n k t o n , b e n t h i c i n v e r t e b r a t e s and f i s h - - t h e i r s i m p l i f i e d r e l a t i o n s h i p i s diagrammed i n F i g u r e 15. The a l g a e p h o t o s y n t h e s i z e new o r g a n i c m a t e r i a l u s i n g l i g h t as energy and c a r b o n a t e , n i t r a t e , phosphate and o t h e r n u t r i e n t s as b u i l d i n g 127 F i g u r e 14. G r a p h i c a l c a l c u l a t i o n s o f h a l f s a t u r a t i o n c o n s t a n t s f o r n i t r a t e ( E p p l e y and Thomas, 1969) and phosphate(Dugdale, 1967). 128 MAN-INDUCED NATURAL I INPUTS i BENTtfiC F i g u r e 15 DEFINITION OF AN AQUATIC ECOSYSTEM (Chen and O r l o b , 1972) 129 b l o c k s . Each of the o t h e r t r o p h i c groups i n c o r p o r a t e s some of t h a t o r g a n i c m a t e r i a l i n t o i t s own body and some i s t r a n s f o r m e d back i n t o i n o r g a n i c s . The p r o d u c t i o n of any p a r t i c u l a r l e v e l depends on the amount of o r g a n i c m a t e r i a l p r e s e n t a t the l e v e l below. The p h y s i c a l parameters which determine the p r i m a r y p r o d u c t i o n , t h a t i s a l g a l biomass, a l s o d e t e r m i n e the t o t a l p r o d u c t i o n due t o the c h a i n l i n k e d dependence of the upper t r o p h i c l e v e l s . These components a r e l i g h t , water t e m p e r a t u r e , abundance and a v a i l a b i l i t y of n u t r i e n t s , and r a t e of n u t r i e n t l o s s . Many s t a n d i n g n a t u r a l systems r e c y c l e . D e n s i t y b a r r i e r s s e t up by temperature d i f f e r e n c e s i n the upper and lower l a y e r s of l a k e s cause l i m i t e d c i r c u l a t i o n i n the summer which c o u p l e d w i t h n a t u r a l s e t t l i n g of dead organisms, causes l i m i t e d a v a i l a b i l i t y of n u t r i e n t s . When the temperature b a r r i e r i s l o s t i n the f a l l and s p r i n g and complete c i r c u l a t i o n o c c u r s a g a i n , the l a k e becomes abundant i n n u t r i e n t s a g a i n . b. M o d e l l i n g Models of a q u a t i c systems can model, i n d e c r e a s i n g c o m p l e x i t y : 1) the ecosystem, 2) p r o d u c t i v i t y , 3) a p o p u l a t i o n , or 4) a p r o c e s s (Dugdale, 1975). The major p r e s e n t m o d e l l i n g emphasis i s t o work up the s c a l e towards ecosystem models, which a r e p r e s e n t l y s t i l l too 1 30 complex f o r our m o d e l l i n g c a p a b i l i t i e s . P r o d u c t i v i t y m o d e l l i n g , which has blossomed i n the l a s t 10 y e a r s , i s o l a t e s the major ecosystem components and r e l a t e s t h e i r p r o d u c t i o n t o the major d r i v i n g e n v i r o n m e n t a l v a r i a b l e s . The approach i n t h i s paper i s t o c o n s i d e r models which are r e l e v a n t t o the concept of a c o n t r o l l e d m u l t i - t r o p h i c l e v e l c u l t u r e system, where a l g a e , z o o p l a n k t o n and f i s h a re grown i n s e p a r a t e c o n t a i n e r s . T h i s approach g r e a t l y s i m p l i f i e s the m o d e l l i n g by a l l o w i n g no feedback l o o p s between the components: n u t r i e n t s -s u n l i g h t — A l g a l C u l t u r e ± Zooplankton C u l t u r e F i s h C u l t u r e The system a l s o a l l o w s f o r o p t i m i z a t i o n of p r o d u c t i o n a t each l e v e l w i t h o u t concern over i n t e r f e r e n c e . B e f o r e m o d e l l i n g an a q u a t i c ecosystem a u n i t of measurement (common c u r r e n c y ) must be chosen t o use i n keeping t r a c k of the exchanges made from one t r o p h i c l e v e l t o the o t h e r s . We can use biomass or the amount of wet or d r y weight 131 m a t e r i a l which i s exchanged but the f a c t t h a t d i f f e r e n t l e v e l s may a c q u i r e mass by a d d i n g water r a t h e r than as r e a l l y n u t r i t i o n a l l y u s e f u l growth must be taken i n t o a c c o u n t . A more s t r i n g e n t c u r r e n c y i s energy, and even though i t i s d i f f i c u l t t o keep t r a c k of energy changes, a l l components of the system can be measured i n terms of energy, i n c l u d i n g the p r i m a l source of s o l a r i n p u t ( V i n o g r a d o v , 1972). Winberg (1971) suggests u s i n g an energy c o n v e r s i o n f a c t o r from r a t i o n t o weight i n c r e a s e (energy of weight i n c r e a s e + energy of metabolism = p h y s i o l o g i c a l l y u s e f u l energy = 0.8 X energy of r a t i o n ) . M e t a b o l i c energy i s taken as the energy e q u i v a l e n t of the oxygen consumption of the f i s h . In t a l k i n g of f o o d s t u f f s , where p r o t e i n i s the r e a l l y i m p o r t a n t component, o f t e n t o t a l , crude or p r o t e i n n i t r o g e n i s used t o keep t r a c k of l o s s e s and t o e v a l u a t e e f f i c i e n c y of t r a n s f o r m a t i o n s . C. A l g a l Growth The a l g a l p o p u l a t i o n forms the f o u n d a t i o n of the f o o d pyramid l e a d i n g t o the f i s h . P r i m a r y p r o d u c t i o n has been m o d e l l e d q u i t e e x t e n s i v e l y and the f a c t o r s most v i t a l l y a f f e c t i n g growth r a t e - - t e m p e r a t u r e , l i g h t , n u t r i e n t s - - have been r e p r e s e n t e d m a t h e m a t i c a l l y i n d i f f e r e n t ways ( J o r g e n s e n , 1983; P a t t e n , 1968). 1 32 a. L i g h t Most a q u a t i c models can be c a t e g o r i z e d m a i n l y i n the way t h a t they t r e a t l i g h t . J o r g e n s e n (1983) i l l u s t r a t e d f i f t e e n e q u a t i o n s showing the response of p h o t o s y n t h e t h i s t o i n c i d e n t l i g h t and e l e v e n e q u a t i o n s t o r e l a t e i n c i d e n t l i g h t t o depth of water and o t h e r e n v i r o n m e n t a l v a r i a b l e s . S i n c e l i g h t c o n c e n t r a t i o n d e c r e a s e s w i t h d e p t h , p r o d u c t i o n must be i n t e g r a t e d over the depth of a l g a l o c c u r r e n c e and l i g h t p e n e t r a t i o n t o a r r i v e a t a net f i g u r e f o r p r o d u c t i o n . For s h a l l o w , c i r c u l a t e d c u l t u r e , o n l y the models r e l a t e d t o time need be c o n s i d e r e d . P h o t o s y n t h e t i c r a t e i n c r e a s e s w i t h i n c r e a s i n g l i g h t c o n c e n t r a t i o n but l e v e l s o f f a t an a s y m p t o t i c v a l u e a t h i g h l i g h t i n p u t (Aruga, 1965) ( F i g u r e 16a). T h i s shows 'the a c c l i m a t i o n a b i l i t y of a l g a e t o d i f f e r e n t l i g h t c o n c e n t r a t i o n s ( Z i s o n e t a l . , 1978). Many a u t h o r s use the M i c h a e l i s - M e n t o n e q u a t i o n t o model a l g a l p r o d u c t i o n ( O ' B r i e n , 1974; Droop, 1973; T o e r i e n and Huang, 1973; Caperon and Meyer, 1972; Dugdale and W h i t l e d g e , 1970; E p p l e y and Thomas, 1969; Dugdale, 1967). T h i s type of e q u a t i o n o n l y f o l l o w s the l i g h t v e r s u s p h o t o s y n t h e t i c r a t e c u r v e up u n t i l the maximum r a t e i s reached. A s e l f - s h a d i n g f a c t o r must be i n c o r p o r a t e d i n t o the model t o account f o r the e f f e c t i n dense c u l t u r e s of the s u r f a c e a l g a e c u t t i n g o f f the l i g h t from deeper a l g a e , thus d e c r e a s i n g t h e i r growth r a t e . MacKenzie (1975) used another approach t o l i g h t l i m i t a t i o n by r e l a t i n g the growth r a t e t o the optimum l i g h t c o n c e n t r a t i o n : 133 i i i i i » ' e 1 / — • *>"8 • 1 * is'c | — 1 : 1 h—f 1 1 10*C J'o 30 oo to ao IOO L 1 « * * l i l i M U ; ( U»i ) a. Photosynthesis-light curves and respiration-temperature curve of Chlorella ellipsoidea grown at ca. 20°. 1 20'C • k f I /s • 10*0 • ».» t«.« to-. io n *o to M lao D. Photosynthesis-light curves and respiration-temperature curve of Scmedesm.ua sp. grown at ca. 20°. 1 i » ' o • . — 10*0 < f • 10 JO ao 10 I 1 ( a t t a l . a a t l r ( Una ) 10 30 i » • r . r o ) C. Photosynthesis-light curves and respiration-temperature curve of Synedra sp. from a eutrophic pond Shinjiike (ca. 20°, June 16, 1961). 1 * a . Photosynthesis-temperature curves of Scenedesmu* sp. at various li^ht intensity. Redrawn from Fig. 2. 50 g Pnntnsynthesis-tcmpcrnttirv curves of Synedra f . Photosynthesis-temperature curves of Chlorella sp. (A), Anabnena cylindrica (li), Chlorella ellivaoidea ellipsoidea grown at different temperature indicated. (C) and Scenedexmv* sp. (D). Figure 16. The Effect of Temperature and Light Intensity on Photosynthesis(from Amga, 1965) 1 34 u = umax*R (23) R o * e x p ( 1 - R / R o ) w h e r e : R = l i g h t i n t e n s i t y , Ro = o p t i m a l l i g h t i n t e n s i t y . A t h i g h l i g h t i n t e n s i t i e s , t h i s e q u a t i o n shows a g r o w t h r a t e s u p r e s s i o n , m o d e l l i n g t h e l i g h t i n h i b i t i o n e f f e c t ( a s i n F i g u r e s 16b and 16c, a t h i g h t e m p e r a t u r e s ) . b. N u t r i e n t s T h e r e i s some c o n t r o v e r s y w h e t h e r o n l y t h e most l i m i t i n g n u t r i e n t s h o u l d be u s e d i n a m o d e l , i n a c c o r d a n c e w i t h L e i b i g ' s Law of t h e Minimum, o r w h e t h e r t h e i n t e r a c t i o n b e t w e e n n u t r i e n t s i s a d e q u a t e l y m o d e l l e d by c o n s i d e r i n g e a c h a s s e p a r a t e l i m i t i n g i n f l u e n c e s i n t h e Monod s t y l e . N u t r i e n t s w h i c h a r e i m p o r t a n t t o a l g a l g r o w t h a r e c a r b o n ( a s c a r b o n d i o x i d e ) , n i t r o g e n ( a s n i t r a t e ) a n d p h o s p h o r u s ( a s p h o s p h a t e ) . Thus f o r t h e t h r e e l i m i t i n g n u t r i e n t s N, P, C, t h e g r o w t h r a t e i s d e t e r m i n e d by: jj=jumax*[N/(N+kn) ]*[P/(P+Kp) ]*[C/(C+Kc) ] (24) w h e r e : Kn, Kp, and Kc a r e t h e h a l f s a t u r a t i o n c o n s t a n t s f o r n i t r a t e , p h o s p h a t e and c a r b o n a t e , r e s p e c t i v e l y . The s o u r c e o f c a r b o n a t e i n w a t e r i s t h e c a r b o n d i o x i d e o f t h e a i r and o r g a n i c r e s p i r a t i o n . Any w e l l m i x e d w a t e r c a n be c o n s i d e r e d t o be h a v i n g s u f f i c i e n t c a r b o n , h o w e v e r , most d e n s e c u l t u r e s h ave i n c l u d e d c a r b o n d i o x i d e a d d i t i o n , u s u a l l y a s a 1% t o 15% m e t e r e d a d d e d component t o a e r a t i o n w i t h c o m p r e s s e d a i r , b e c a u s e t h e demands o f a d e n s e c u l t u r e a r e v e r y h i g h and b e c a u s e c a r b o n d i o x i d e i s r e l a t i v e l y c h e a p . 1 35 Sources of n i t r o g e n and phosphorus can be both o r g a n i c and i n o r g a n i c , i n which case the o r g a n i c m o l e c u l e s must be broken down t o the p r i m a l n i t r a t e and phosphate b e f o r e they can be u t i l i z e d by the a l g a e . The p r e s ence of a n u t r i e n t i s not the o n l y l i m i t i n g f a c t o r , but the s t a t e of t h a t n u t r i e n t i s a l s o i m p o r t a n t . T h e r e f o r e , even though n i t r o g e n i s a b u n d a n t l y p r e s e n t i n manure, as p r o t e i n s , ammonia and u r e a , i t i s not u s e f u l t o an a l g a l c u l t u r e u n t i l i t i s degraded t o the n i t r a t e form. N i t r o g e n has l o n g been thought to be the most im p o r t a n t l i m i t i n g n u t r i e n t , b u t , a g a i n a c c o r d i n g t o L e i b i g ' s Law of the Minimum, phosphate i s i n much l e s s abundant s u p p l y w o r l d wide and cannot be s y n t h e s i z e d from e l e m e n t a l phosphorus as n i t r a t e can be from gaseous N i t r o g e n , of which t h e r e i s an e n d l e s s a t m o s p h e r i c s u p p l y . C e r t a i n m i c r o n u t r i e n t s may be l i m i t i n g but t h i s i s the documented case i n o n l y a v e r y few q u i t e unique l o c a l e s . Chen (1970) g i v e s v a l u e s f o r h a l f - s a t u r a t i o n c o n s t a n t s f o r c a r b o n , n i t r o g e n and phosphate. c. R e s p i r a t i o n A l gae r e s p i r e a l l the t i m e , a l t h o u g h when they a r e p h o t o s y n t h e s i z i n g , a net p r o d u c t i o n of oxygen and d e p l e t i o n of n u t r i e n t s o c c u r s . Rate of r e s p i r a t i o n , l i k e r a t e of growth, depends on the p o p u l a t i o n s i z e and p a r t i c u l a r l y on the r a t e of m e t abolism. M e t a b o l i s m , as an enzyme f u n c t i o n , i s dependent, o u t s i d e of s u b s t r a t e c o n c e n t r a t i o n , m o s t l y on t e m p e r a t u r e , and u s u a l l y has some k i n d of optimum w o r k i n g t e m p e r a t u r e , above and below which the r a t e d e c r e a s e s . T h i s i s e x p r e s s e d g r a p h i c a l l y 1 36 i n F i g u r e s 16d, e, and f . T h i s r e l a t i o n s h i p i s c l e a r l y e x p o n e n t i a l and can be e x p r e s s e d m a t h e m a t i c a l l y a s : R = rmax * 0**(T-2O) (25) where: R = the r e s p i r a t i o n r a t e at t e m p e r a t u r e , T, rmax = the r e s p i r a t i o n r a t e at 20 degrees c e l s i u s , and 9 = a c o n s t a n t which r e l a t e s these t o one another and v a r i e s from 1.02-1.06 depending on the r e a c t i o n i n v o l v e d ( Z i s o n e t a l . , 1978). d. C a r r y i n g C a p a c i t y A l g a l p o p u l a t i o n must r e a c h a maximum d e n s i t y i f a l l l i m i t i n g f a c t o r s are m a i n t a i n e d above l i m i t i n g v a l u e s . The Monod e q u a t i o n d e a l s w i t h the r e l a t i o n s h i p of n u t r i e n t c o n c e n t r a t i o n and growth r a t e , but a t some p o i n t the growth r a t e must d e c r e a s e t o z e r o , as the c a r r y i n g c a p a c i t y of the system i s reached. C a r r y i n g c a p a c i t y (Cc) can be t r e a t e d as a maximum i n s t e a d of a h a l f - s a t u r a t i o n c o n s t a n t , such t h a t : P2=P1+P1 *jumax* (Cc -P1 )/Cc ) (26) Thus as the p o p u l a t i o n approaches the c a r r y i n g c a p a c i t y , the growth r a t e approaches z e r o . However, s e l f s h a d i n g of l i g h t by the i n c r e a s e i n p o p u l a t i o n s i z e a l s o s e r v e s as a means of l i m i t i n g c a r r y i n g c a p a c i t y . 1 37 D. Zooplankton Growth a. F a c t o r s I n v o l v e d Some s i m i l a r and some d i f f e r e n t f a c t o r s c o n t r o l the growth of z o o p l a n k t o n . Maximum growth r a t e i s dependent upon m e t a b o l i c r a t e which a g a i n can be c o n s i d e r e d a f u n c t i o n of te m p e r a t u r e , and on abundance of n u t r i e n t s , i n t h i s case a l g a l f o o d . Oxygen p l a y s much the same p a r t f o r z o o p l a n k t o n as carbon d i o x i d e does f o r a l g a e , however, i n s h a l l o w , w e l l c i r c u l a t e d ponds oxygen i s r a r e l y l i m i t i n g because of i t s tremendous abundance i n the a i r (20%) compared t o i t s s o l u b i l i t y i n water (10 ppm a t 15°C). In c a l c u l a t i n g e f f i c i e n c i e s of t r a n s f e r of food energy from a l g a e t o z o o p l a n k t o n , the dry weight body make-up i s o f t e n used i n c o n j u n c t i o n w i t h e s t i m a t e d e f f i c i e n c y v a l u e s . These e s t i m a t e s and e s t i m a t e s based on the l o s s of 90% of the biomass or energy i n each t r o p h i c t r a n s f e r , a r e u s e f u l i n t h e i r way as g r o s s t o o l s , b ut, g o i n g back t o the problems i n 'b l a c k box' m o d e l l i n g , they bear l i t t l e resemblance t o the a c t u a l p h y s i c a l exchange p r o c e s s e s i n v o l v e d , and thus have no s e n s i t i v i t y t o s m a l l changes i n the p h y s i c a l d r i v i n g v a r i a b l e s . Even more d i f f i c u l t t o model a r e the l i f e h i s t o r y parameters which make such a d i f f e r e n c e i n comparing the growth r a t e s , p o p u l a t i o n or i n d i v i d u a l , of d i f f e r e n t s p e c i e s . Q u i t e d i f f e r e n t r a t e s can be seen f o r p o p u l a t i o n growth i n p a r t h e n o g e n i c v e r s u s s e x u a l l y r e p r o d u c i n g a n i m a l s , due t o the d e l a y caused by ma t i n g . A q u a t i c c r u s t a c e a n s go through s e v e r a l l i f e h i s t o r y s t a g e s b e f o r e r e a c h i n g m a t u r i t y . These can be 1 38 t r e a t e d as s e p a r a t e s t a n z a s i n a s t e p - l i k e growth l a d d e r , s i n c e m o l t i n g causes v e r y c o n s i d e r a b l e changes i n i n s t a n t a n e o u s r a t e s (as i n S c h n e i d e r , 1974), or the s e d i f f e r e n c e s can be i g n o r e d and a g r o s s g e n e r a l c u r v e s e t t o f i t the p a t t e r n . The i d e a l i n v e r t e b r a t e model, a c c o r d i n g t o Frank (1960), i n c l u d e s f o r each s p e c i e s : 1) a l l the s i g n i f i c a n t c l a s s e s of the p o p u l a t i o n 2) i n i t i a l numbers per c l a s s 3) b i r t h , d e a t h , i m m i g r a t i o n , e m i g r a t i o n r a t e s per c l a s s 4) biomass and r a t e of p r o d u c t i o n per c l a s s 5) e n v i r o n m e n t a l e f f e c t s on each c l a s s . Gupta and H o u d e s h e l l (1973) o u t l i n e d a model of s e v e r a l d i f f e r e n t t a x a of a q u a t i c organisms i n t e r a c t i n g w i t h one a n o t h e r . There was no da t a base, however, t o make the n e c e s s a r y assumptions about the v a r i o u s c o m p e t i t i o n s , s i n c e the s c i e n c e of p l a n k t o n b i o l o g y has not moved v e r y f a r beyond the d e s c r i p t i v e and c l a s s i f i c a t i o n s t a g e s of development. The type of food and i t s n u t r i t i v e v a l u e a l s o make a g r e a t d i f f e r e n c e t o the growth p a t t e r n of an a n i m a l . I f a n u t r i e n t ( m i n e r a l , v i t a m i n , e s s e n t i a l amino a c i d or f a t t y a c i d ) i s c o m p l e t e l y m i s s i n g , m o r t a l i t y w i l l o c c u r . However, i f a n u t r i e n t i s o n l y i n s h o r t s u p p l y , growth i s s t u n t e d i n ac c o r d a n c e . The s i t u a t i o n i s much more c o m p l i c a t e d w i t h a n i m a l s than w i t h p l a n t s , s i n c e a n i m a l s a r e so much more h e l p l e s s i n s y n t h e s i z i n g what they need from a v a i l a b l e m a t e r i a l s . A c c l i m a t i o n and g e n e t i c p o p u l a t i o n d i v e r s i t y may p l a y l a r g e r o l e s i n the a d a p t a t i o n of a p a r t i c u l a r a n i m a l t o a p a r t i c u l a r 1 39 food s t u f f . Some a l g a e a c t u a l l y exude c h e m i c a l s when they a r e i n a h i g h l y p r o d u c t i v e phase which a r e t o x i c t o p o t e n t i a l g r a z e r s and which a re even t o x i c t o f i s h ( P r e s c o t t , 1948). b. M o d e l i n g One way of g e t t i n g around the problem of t r y i n g t o model a l l of t h e s e i n t e r a c t i n g components i s t o o n l y c u l t u r e z o o p l a n k t o n on a l g a e (or a m i x t u r e of organisms) which a r e known t o a d e q u a t e l y s u p p l y a l l the im p o r t a n t n u t r i e n t s . In t h i s case the p o p u l a t i o n growth of the z o o p l a n k t o n s h o u l d o n l y be l i m i t e d by the p h y s i c a l c a r r y i n g c a p a c i t y of the v e s s e l as l o n g as s u f f i c i e n t food i s p r o v i d e d . Dugdale (1975) c o n s i d e r e d p o p u l a t i o n i n c r e a s e as a f u n c t i o n of g r a z i n g r a t e : dZ/dt=G*(A-A')/(Ka+A) (27) where: Z = the z o o p l a n k t o n p o p u l a t i o n , G = maximum g r a z i n g r a t e , A = a l g a l c o n c e n t r a t i o n , A 1 = t h r e s h o l d c o n c e n t r a t i o n of a l g a e when the g r a z i n g r a t e = 0, Ka = h a l f s a t u r a t i o n c o n s t a n t i f A'=0. Chen and O r l o b (1972) r e l a t e d p o p u l a t i o n t o growth r a t e , m o d i f i e d by t e m p e r a t u r e , a l g a l c o n c e n t r a t i o n and r e s p i r a t i o n r a t e : dZ/dt = Z*[ >umax*9**(T-20)*A/(A+Ka) ] - [ rmax*0** (T-20 ) ]-H (28) where: jumax = maximum growth r a t e , T = water t e m p e r a t u r e , 0 = a c o n s t a n t , A = a l g a l c o n c e n t r a t i o n , Ka = h a l f s a t u r a t i o n c o n s t a n t f o r z o o p l a n k t o n f e e d i n g on a l g a e , rmax = maximum r e s p i r a t i o n r a t e , h a r v e s t (H)= l o s s e s from the system. 1 40 E. F i sh Growth a. F a c t o r s A f f e c t i n g Growth H a s k e l l (1959) r e v i e w e d the f a c t o r s t h a t have the g r e a t e s t i n f l u e n c e on the growth of t r o u t i n h a t c h e r i e s . H i s l i s t i n c l u d e d water t e m p e r a t u r e , c a r e , s p e c i e s , r a c e , d i e t , f e e d i n g l e v e l , h e a l t h , and s e x u a l m a t u r i t y . Other f a c t o r s , from S t a u f f e r (1973) are s o c i a l h i e r a r c h y , age, s i z e , a c t i v i t y and p h o t o p e r i o d i s m . By ' c a r e ' , H a s k e l l means the 'good house-keeping' p r a c t i c e s by the f i s h c u l t u r i s t which i n c l u d e p r o p e r f e e d i n g t e c h n i q u e s , m i n i m a l food wastage, p r o v i d i n g adequate oxygenated water s u p p l y which f l u s h e s out o r g a n i c wastes, r e g u l a r pond c l e a n i n g and 'disease p r o p h y l a x i s or d i a g n o s i s and t r e a t m e n t . F o r t u n a t e l y the methods of c a r i n g f o r f i s h a r e w e l l c o d i f i e d ( L e i t r i t z and L e w i s , 1976) and t r o u t f a c i l i t i e s a r e d e s i g n e d t o p r o v i d e the b e s t c a r e , thus i t i s u nnecessary t o t r y t o model t h i s most s u b j e c t i v e of the growth components. F i s h h e a l t h i s a n o t h e r v e r y a l l encompassing term, s i n c e the onset of d i s e a s e can most o f t e n e i t h e r be t r a c e d t o s l i g h t n e g l i g e n c e i n c a r e , or t o no p r e d i c t a b l e f a c t o r a t a l l . T h e r e f o r e the r e t a r d e n t a f f e c t t h a t poor h e a l t h has on f i s h can be i n c l u d e d as p a r t of the c a r e f a c t o r , e i t h e r b e i n g i g n o r e d ( t h a t i s , we a r e o n l y m o d e l l i n g the w e l l managed farm) as does S t a u f f e r (1973), or t r e a t i n g the o c c u r r e n c e of an e p i z o o t i c or o t h e r massive t r a g e d y as a random s t a t i s t i c a l p r o b a b i l i t y , as d i d C a l l a g h a n and C a l l a g h a n (1974). 141 The f i s h d i e t i s i m p o r t a n t , both i t s makeup and the amount and fr e q u e n c y of f e e d i n g . M o d e l l i n g the e f f e c t s of v a r i o u s d i e t s c o u l d be done u s i n g some k i n d of c o n v e r s i o n f a c t o r s as the e s s e n t a l components are known i n some d e t a i l ( Z e i t a u n et a l . , 1976). However, s i n c e f o r m u l a t e d d i e t s have v e r y s i m i l a r p e r c e n t a g e s of the e s s e n t i a l components ( B i s s e l , 1974), such d e t a i l i s not u s u a l l y c o n s i d e r e d . The complex b i o c h e m i c a l i n t e r a c t i o n s make the m o d e l l i n g of v a r i a t i o n i n one component p r a c t i c a l l y i m p o s s i b l e , and the u s u a l approach i s t o e x p e r i m e n t a l l y f i n d an optimum v a l u e f o r each v i t a l n u t r i e n t ( i n d a i l y dosage or per cent of t o t a l d i e t ) and use those v a l u e s i n f o r m u l a t i n g a f e e d m i x t u r e . Much more e a s i l y m o n i t o r e d i s the amount of food p r e s e n t e d t o the f i s h . The s i z e of r a t i o n has r e c e i v e d c o n s i d e r a b l e r e s e a r c h as a most i m p o r t a n t d r i v i n g v a r i a b l e ( L e B r a s s e u r , 1969), s i n c e food i s the source of energy and b u i l d i n g b l o c k s f o r growth and a l s o the producer of m e t a b o l i c wastes and oxygen demand ( B r e t t , 1971). In a c h i e v i n g minimum wastage, the f i s h a r e f e d a t one f e e d i n g s e s s i o n no more than they can i n g e s t and m e t a b o l i z e b e f o r e the next s e s s i o n , thus s i z e of r a t i o n must be c o o r d i n a t e d w i t h the f r e q u e n c y of f e e d i n g . T h i s may a l s o be r e l a t e d t o the p h o t o p e r i o d (amount of d a y l i g h t hours a v a i l a b l e ) i n which f e e d i n g may o c c u r , a l t h o u g h r e s e a r c h on the a f f e c t of p h o t o p e r i o d on growth i s i n c o n c l u s i v e ( S t a u f f e r , 1973). Rough e s t i m a t e s or f e e d u t i l i z a t i o n , c a l l e d c o n v e r s i o n r a t e s ( v a l u e s of 1.0:1.0 t o 2.3:1.0 f o r wet weight c o n v e r s i o n s of food t o f i s h ) a r e o f t e n used but the water c o m p o s i t i o n of the feeds i s 1 42 q u i t e v a r i a b l e . A c t u a l c o n v e r s i o n of n i t r o g e n i n the feed t o n i t r o g e n i n the f l e s h i s more i n the l i n e of 5.0:1.0 t o 8.0:1.0. S t a p l e s and Nomura (1976), however, r e p o r t a 71.7% energy a s s i m i l a t i o n e f f i c i e n c y f o r rainbow t r o u t . The s p e c i e s of f i s h makes a b i g d i f f e r e n c e t o the growth r a t e or food c o n v e r s i o n r a t e . In a d d d i t i o n , the race of a p a r t i c u l a r s p e c i e s and the s o c i a l h i e r a r c h y of p a r t i c u l a r f i s h w i t h i n an e n c l o s u r e a l s o makes a d i f f e r e n c e . The s p e c i e s and race v a l u e s , i f they can be d e t e r m i n e d , a r e i n c o r p o r a t e d i n t o a growth model through some maximum p o s s i b l e growth f a c t o r . S o c i a l h i e r a r c h y i s too s u b j e c t i v e and v a r i a b l e t o be m o d e l l e d on a l a r g e s c a l e , but c e r t a i n d i f f e r e n t f i s h c u l t u r a l p r a c t i c e s tend to induce more marked v a r i a t i o n i n the range of s i z e s of f i s h of the same age i n the same pond under i d e n t i c a l f e e d i n g regimes. Ponded f i s h a r e more o f t e n l e s s u n i f o r m i n s i z e than more d e n s e l y packed raceway f i s h , the s p e c u l a t i o n b e i n g t h a t i n the crowded c o n d i t i o n s of a raceway the f i s h a c t as i f s c h o o l i n g , but when g i v e n more space, they become t e r r i t o r i a l and v i e f o r dominance. Such s u b j e c t i v e d i s t i n c t i o n s a r e beyond the scope of our model. Swimming a c t i v i t y , or the l a c k of i t , can a f f e c t c o n v e r s i o n e f f i c i e n c i e s and growth r a t e s , as swimming uses up energy which c o u l d be used f o r growth. There i s some concern about smolt q u a l i t y i n r e l e a s e h a t c h e r i e s , t h a t a l t h o u g h l a r g e s m o l t s have been produced, they a r e slow and l a z y and t h e r e f o r e do not s u r v i v e w e l l i n the w i l d , but t h e r e i s no need f o r such concern i n farmed f i s h , u n l e s s the q u a l i t y of the meat i s 1 43 a f f e c t e d . T h i s f a c t o r i s n o r m a l l y i n c o r p o r a t e d as a d e s i g n parameter, t h a t c e r t a i n minimum and maximum v e l o c i t i e s s h o u l d be met f o r raceways t o g i v e a compromise between f a s t enough t o c l e a n out s o l i d wastes and slow enough so as not t o over e x e r c i s e the f i s h . S p e c i f i c growth r a t e s of f i s h d e c r e a s e as f i s h i n c r e a s e i n s i z e and age ( S t a p l e s and Nomura, 1976), a l t h o u g h the r e l a t i o n between s i z e and age i s confounded ( B r e t t et a l . , 1969). I f growth r a t e i s d e t e r m i n e d by changes i n environment, such as temperature or r a t i o n , then i t i s b e t t e r t o c o n s i d e r growth as a f u n c t i o n of s i z e r a t h e r than age ( S t a u f f e r , 1973). The e f f e c t of temperature on growth r a t e of f i s h has been w e l l demonstrated r i g h t up the b i o l o g i c a l h i e r a r c h y from enzyme k i n e t i c s t o f e e d i n g t r i a l s . S t a u f f e r (1973) summarizes t h a t r a t i o n , s i z e and temperature a r e the t h r e e most i m p o r t a n t f a c t o r s i n f l u e n c i n g growth r a t e of f i s h e s . b. Models S t a u f f e r (1973) used a c o m b i n a t i o n of f u n c t i o n s t o compute the growth r a t e of young chinook salmon based on t h r e e main d r i v i n g v a r i a b l e s : a power f u n c t i o n f o r f i s h w e i g h t , a s i n e c u r v e l o g i s t i c f o r f e e d r a t e and a p o l y n o m i a l f o r t e m p e r a t u r e . T h i s model, used i n a computer h a t c h e r y s c h e d u l i n g program (Johnson, 1974) i s : W2=W1 *exp[jumax*f (T) *W1 ** (- 1/3 ) * s i n { ( lf/2)*(R-Rm)/(Rx-Rm) } ] (29) where: W1 = i n i t i a l weight of the f i s h , W2 = f i n a l weight of the f i s h , ^imax = maximum s p e c i f i c growth r a t e , f ( T ) 1 44 temperature f u n c t i o n , R = d a i l y r a t i o n , Rm = maintenance r a t i o n , Rx = maximum r a t i o n t h a t can be f e d . In the working program, these v a l u e s a r e computed from formulae r e l a t i n g them to the pond water t e m p e r a t u r e , the i n i t i a l weight of the f i s h and a s e t of 15 parameter v a l u e s . T h i s model i s used by the Canadian Department of F i s h e r i e s and Oceans f o r p r e d i c t i o n of salmon growth a t t h e i r Salmonid Enhancement F a c i l i t i e s . Papst et a l . (1982) dropped the c o m p l i c a t e d f e e d r a t e f u n c t i o n from the S t a u f f e r e q u a t i o n because farm r e a r e d t r o u t are a lmost u n i v e r s a l l y f e d on f u l l r a t i o n (making the fee d r a t e f u n c t i o n i n the e q u a t i o n e q u a l t o 1.0). They then r e - v e r i f i e d the S t a u f f e r temperature p o l y n o m i a l u s i n g a v a r i e t y of s t r a i n s of rainbow t r o u t , l e a d i n g t o the f o l l o w i n g e s t i m a t i o n : f (T) =0.6087-0. 1 27*T+0.0'54*T 2-0.0035*T 3 + 0.000062*T« (30) where: T = temperature i n degrees c e n t i g r a d e . Sperber et a l . (1977) extended U r s i n ' s (1967) model based on the b a l a n c e of a n a b o l i c and c a t a b o l i c p r o c e s s e s t o i n c l u d e s t o c h a s t i c f e a t u r e s t o model d i f f e r e n t i a l growth i n t r o u t farm ponds w i t h i n the same b a t c h of f i s h . T h i s model was i n c o r p o r a t e d i n t o a Ma r k o v i a n d e c i s i o n model ( S p a r r e , 1976), which e v a l u a t e d management d e c i s i o n s i n o p t i m i z i n g farm p r o d u c t i o n . These models a r e v e r y s p e c i f i c t o t h e i r purposes and w i l l not be i l l u s t r a t e d h e r e , s i n c e t h e i r t e r m i n o l o g y i s e x t e n s i v e and i s not g o i n g t o be used i n t h i s a n a l y s i s . Iwama and Tautz (1981) proposed an e x t r e m e l y s i m p l e model f o r f i s h growth a f t e r s e n s i t i v i t y a n a l y s e s of the c o e f f i c i e n t s of v a r i o u s o t h e r models showed t h a t the c o e f f i c i e n t s were not 145 v e r y s e n s i t i v e . W2 = W1**(-l/3) + (T/1000) * t (31) where: T = average temperature (°C); t = time i n days. T h i s model i s used by the B. C. F i s h and W i l d l i f e Branch f o r p r e d i c t i o n of t r o u t growth a t t h e i r f i s h c u l t u r e s t a t i o n s . The main problem w i t h t h i s model i s t h a t i t p r e d i c t s g r e a t e r and g r e a t e r growth as temperature i n c r e a s e s . A c t u a l t r o u t growth s t a r t s t o de c r e a s e r a p i d l y a f t e r 15 ° C, so the model i s of no use above t h a t t e m p e r a t u r e . T h i s model a l s o o v e r e s t i m a t e s growth at low temperatures (below 6 ° C ) . The p o l y n o m i a l temperature f u n c t i o n a l l o w s f o r the s e non-smooth e f f e c t s of temperature on growth. Chen and O r l o b ' s (1970) model f o r f i s h growth i s of the M i c h a e l i s - M e n t e n t y p e , such t h a t : W2=W1*exp[({/jmax*Z/(Z+Kz) }-{rmaxJ*J3** (T-20))-HJ (32) where: Z = z o o p l a n k t o n c o n c e n t r a t i o n , Kz = h a l f s a t u r a t i o n c o n s t a n t f o r f i s h f e e d i n g on z o o p l a n k t o n , jumax = maximum growth r a t e , rmax = maximum r e s p i r a t i o n r a t e , 0 = c o n s t a n t , h a r v e s t (H) = l o s s e s from d i s e a s e , m o r t a l i t y , f i s h i n g . A g a i n , the temperature f u n c t i o n i s i n c o r r e c t , s i n c e i t p r e d i c t s t h a t the growth r a t e w i l l c o n t i n u e t o i n c r e a s e no matter how h i g h the te m p e r a t u r e . 1 46 F. A b i o t i c F a c t o r s Throughout the d i s c u s s i o n s of the growth of the b i o l o g i c a l components of the c o n t r o l l e d ecosystem, c e r t a i n p h y s i c a l and c h e m i c a l components were c i t e d as b e i n g d r i v i n g v a r i a b l e s of the b i o l o g i c a l p r o c e s s e s . I t makes sense, t h e r e f o r e , t o i n c o r p o r a t e i n t o any ecosystem model a s e c t i o n which keeps account of changes, consumption and p r o d u c t i o n of these v a r i a b l e s . The number of v a r i a b l e s which c o u l d be c o n s i d e r e d i s innumerable i n an open system, but the more i m p o r t a n t ones a r e d i s c u s s e d below. L i g h t i s the o r i g i n a l source of energy i n a l g a l c u l t u r e s . I t s maximum use i s d e t e r m i n e d by the amount a v a i l a b l e but u n l i k e n u t r i e n t s which s t a y around u n t i l used up, i s c o n s i d e r e d an i n s t a n t a n e o u s q u a n t i t y . A l a r g e p o p u l a t i o n , h a v i n g a g r e a t e r i n s t a n t a n e o u s uptake r a t e , can more e f f i c i e n t l y use s u n l i g h t than a s m a l l p o p u l a t i o n , but too many s u r f a c e a l g a e may use up a l l t he l i g h t , and c o m p l e t e l y shade out deeper water. L i g h t p e n e t r a t i o n i n t o water depends on the i n i t i a l l i g h t i n t e n s i t y ( d i s t a n c e from the sun, c l o u d c o v e r , a t m o s p h e r i c h u m i d i t y , a n g l e of the sun i n the sky, and smoothness of the water s u r f a c e , W e t z e l , 1975). S u r f a c e r a d i a t i o n can be c a l c u l a t e d from l a t i t u d e , l o n g i t u d e , e l e v a t i o n and r e l a t i v e h u m i d i t y (Chen, 1970). Water te m p e r a t u r e can be m o n i t o r e d i n a model u s i n g heat t r a n s f e r p r i n c i p l e s and computer c a l c u l a t i o n l i n k e d t o the d e s i g n d e t a i l s and e n v i r o n m e n t a l parameters such as ambient day and n i g h t a i r t e m p e r a t u r e s , i n f l o w water t e m p e r a t u r e , and 147 d i r e c t s u n l i g h t . The c a l c u l a t i o n s f o r s u b t l e heat changes a r e q u i t e complex. However, g r o s s changes i n l a r g e volumes of f l o w i n g water over s h o r t d i s t a n c e s can be c o n s i d e r e d n e g l i g i b l e due t o the h i g h s p e c i f i c heat of w a t e r . A g r o s s c a l c u l a t i o n of the heat t r a n s f e r t o a s h a l l o w (1 meter) pond w i t h parameters e s t i m a t e d f o r the s i t e i n q u e s t i o n i n d i c a t e d t h a t v i r t u a l l y a l l the heat accumulated from the sun d u r i n g the day i s l o s t t h r o u g h r a d i a t i o n t o the sky a t n i g h t . Thus a pond would need t o be c o v e r e d t o r e t a i n much heat (Kramer, C h i n and Mayo, 1976). The temperature of waters mixed from d i f f e r e n t s o u r c e s can be approximated by a p r o p o r t i o n a t e a v e r a g i n g of the source t e m p e r a t u r e s . M a t h e m a t i c a l l y , y e a r l y t emperature f l u c t u a t i o n s t e n d t o f o l l o w p e r i o d i c c u r v e s and can be a p p r o x i m a t e d u s i n g F o u r i e r f u n c t i o n s (Wayland, 1957) as has been done by McLean (1979). N u t r i e n t s a r e used up and e x c r e t e d i n p r o p o r t i o n t o the s i z e of the b i o l o g i c a l p o p u l a t i o n p r e s e n t . T h e r e f o r e , n u t r i e n t s can be t r e a t e d as mass b a l a n c e problems. When t h e r e i s a growth of a l g a e , t h e r e w i l l be a c o r r e s p o n d i n g uptake of N i t r o g e n and Phosphorus, a c c o r d i n g t o t h e i r p r o p o r t i o n a t e p e r c e n t c o m p o s i t i o n s i n the a l g a e . S i m i l a r l y as f i s h eat a c e r t a i n amount of n i t r o g e n o u s m a t e r i a l , c o n v e r t i n g a p e r c e n t a g e of i t i n t o f i s h biomass, the complement of t h a t p e r c e n t a g e must be waste, and show up as s o l i d or d i s s o l v e d n i t r o g e n o u s compounds i n the w a t e r . N i t r o g e n o u s wastes may presumably be d e n i t r i f i e d t o e l e m e n t a l N i t r o g e n and l e a v e the system as N i t r o g e n gas. However, some time i n a n a e r o b i c c o n d i t i o n s i s r e q u i r e d f o r such 1 48 an escape (Meade and Kenworthy, 1974). The i m p o r t a n t gases f o r l i f e , carbon d i o x i d e and oxygen, may a l s o become l i m i t i n g under adverse c i r c u m s t a n c e s . The c o m p l i c a t i o n s i n v o l v e d i n m o n i t o r i n g the many p o s s i b l e source and s i n k c o n f i g u r a t i o n s f o r carbon make m o d e l l i n g i t , o t h e r than the C02, i m p r a c t i c a l . Oxygen i s used up both b i o l o g i c a l l y ( i n r e s p i r a t i o n of a l l a n i m a l s , p l a n t s and b a c t e r i a ) and c h e m i c a l l y ( c h e m i c a l oxygen demand). Oxygen i s so e a s i l y i n t r o d u c e d i n t o the system t h a t i t i s common t o a e r a t e anywhere between s t a g e s where oxygen might be consumed. 1 49 I I I METHODOLOGY 150 5 SYSTEMS ANALYSIS METHODS A. G e n e r a l a. D e f i n i t i o n s The word 'system' by i t s e l f and used as a compound noun w i t h o t h e r words has many v e r y s p e c i f i c meanings t o peopl e i n v o l v e d i n d i f f e r e n t k i n d s of work. Each term has d i s t i n c t l y d i f f e r e n t meanings f o r e l e c t r i c a l , c h e m i c a l , b i o m e d i c a l and c i v i l e n g i n e e r s , as w e l l as f o r computer s c i e n t i s t s , b u s i n e s s a c c o u n t a n t s and o p e r a t i o n s r e s e a r c h e r s . We s h a l l t r y t o d e f i n e our approach t o systems and i t s f a m i l y of r e l a t e d terms, u s i n g l o g i c a l c o n n o t a t i o n e x t e n s i o n s of d i c t i o n a r y d e f i n i t i o n s . Lapedes (1974) i n "the D i c t i o n a r y of S c i e n t i f i c and T e c h n i c a l Terms," d e f i n e s the terms as f o l l o w s : System: a method of o r g a n i z i n g e n t i t i e s or i t e m s , i n p a r t i c u l a r o r g a n i z i n g such e n t i t i e s i n t o a l a r g e r a g g r e g a t e . System A n a l y s i s : the use of mathematics t o determine how a set of i n t e r c o n n e c t e d components, whose i n d i v i d u a l c h a r a c t e r i s t i c s a r e known, w i l l behave i n response t o a g i v e n i n p u t or s e t of i n p u t s . Systems A n a l y s i s : the a n a l y s i s of an a c t i v i t y , p r o c e d u r e , method, t e c h n i q u e or b u s i n e s s t o de t e r m i n e what must be a c c o m p l i s h e d and how the n e c e s s a r y o p e r a t i o n s may be a c c o m p l i s h e d . 151 System d e s i g n : a t e c h n i q u e of c o n s t r u c t i n g a system t h a t performs i n a s p e c i f i e d manner, making use of a v a i l a b l e components. A l s o known as s y n t h e s i s . Systems E n g i n e e r i n g : the d e s i g n of a complex i n t e r r e l a t i o n of many elements (a system) to maximize an agreed-upon measure of performance, t a k i n g i n t o c o n s i d e r a t i o n a l l of the elements r e l a t e d i n any way t o the system, i n c l u d i n g u t i l i z a t i o n of manpower as w e l l as the c h a r a c t e r i s t i c s of each of the system's components. A l s o known as system e n g i n e e r i n g . E n g i n e e r i n g : the s c i e n c e by which the p r o p e r t i e s of matter and the source of power i n n a t u r e a r e made u s e f u l t o man i n s t r u c t u r e s , machines and p r o d u c t s . In the broad sense, systems a n a l y s i s does not j u s t mean the t e s t i n g of c o m p u t e r i z e d d a t a h a n d l i n g hardware, as some a u t h o r s would l e a d one t o b e l i e v e , but r e f e r s t o the use of any o r g a n i z a t i o n a l t e c h n i q u e t o a i d i n s i f t i n g t h r o u g h complex component i n t e r r e l a t i o n s h i p s i n o r d e r t o l e a d up t o a 'best f i t ' d e c i s i o n r e g a r d i n g the problem i n v o l v e d . b. Approach A c c o r d i n g t o von B e r t a l a n f f y (1968), the c r e d i t f o r the d i s c o v e r y and development of G e n e r a l Systems Theory, the d o c t r i n e of p r i n c i p l e s a p p l y i n g t o a l l systems, s h o u l d go m o s t l y t o von B e r t a l a n f f y , h i m s e l f , who had been a d v o c a t i n g , s i n c e the 1920's, a m u l t i - d i s c i p l i n a r y approach t o problems t o 1 52 c o u n t e r i n c r e a s i n g s p e c i a l i z a t i o n . Weinberg (1975) says t h a t the purpose of g e n e r a l systems t e c h n i q u e s i s t o h e l p s c i e n t i s t s u n r a v e l c o m p l e x i t y , t o h e l p t e c h n o l o g i s t s master i t and t o h e l p o t h e r s l e a r n t o l i v e w i t h i t . S c i e n c e can d e a l w i t h s m a l l numbers; t h a t i s , the b e h a v i o r under s p e c i f i e d c o n d i t i o n s of an i n d i v i d u a l component. S c i e n c e can a l s o d e a l w i t h l a r g e numbers, s i n c e the l a r g e r the p o p u l a t i o n , the more l i k e l y w i l l o b s e r v e d v a l u e s be c l o s e t o p r e d i c t e d v a l u e s , w i t h i n l i m i t s of u n c e r t a i n t y . However, w i t h i n the range of m i d d l e numbers, t h e r e i s poor s t a t i s t i c a l c o n s i s t e n c y and, as Murphy's Law s t a t e s , a n y t h i n g t h a t can happen w i l l happen. The i Law of Medium Numbers (Weinberg, 1975) s t a t e s " f o r medium number systems we can expect t h a t l a r g e f l u c t u a t i o n s , i r r e g u l a r i t i e s and d i s c r e p a n c i e s w i t h any t h e o r y w i l l occur more or l e s s r e g u l a r l y . " T h i s s u g g e s t s t h a t , t o be a s u c c e s s f u l g e n e r a l i s t , one must j u d i c i o u s l y a p p l y the a r t of i g n o r i n g some da t a and f o c u s i n g on the t r e n d s of phenomena. T h i s l e a d s t o Weinberg's Law of C o n s e r v a t i o n of Laws: "when the f a c t s c o n t r a d i c t the Law, r e j e c t the f a c t s or change the d e f i n i t i o n s , but never throw away the Law." A l t h o u g h o v e r s t a t e d i n t h i s q u o t a t i o n , the s e n t i m e nt i s t h a t an a p p a r e n t l y sound t h e o r y s h o u l d not n e c e s s a r i l y be thrown away the f i r s t time some d a t a appear t o r e f u t e i t . The e x p e r i m e n t a l e v i d e n c e may not be as a c c u r a t e as i t appears or the t h e o r y may be l e s s w i d e l y a p p l i c a b l e than o r i g i n a l l y e x p e c t e d , or i t s t i l l may be the b e s t p r a c t i c a l t h e o r y under c e r t a i n c i r c u m s t a n c e s . T h i s i s 1 53 because g e n e r a l systems laws have a group of p r o p e r t i e s , such t h a t : 1. Any g e n e r a l law must have at l e a s t two s p e c i f i c a p p l i c a t i o n s . 2. Any g e n e r a l law i s bound t o have a t l e a s t two except i ons. 3. The whole set i s g r e a t e r than the sum of i t s p a r t s . 4. The p a r t i s more than a f r a c t i o n of the whole. 5. Laws s h o u l d not depend on a p a r t i c u l a r c h o i c e of n o t a t i o n . 6. The t h i n g s we see most f r e q u e n t l y a r e more f r e q u e n t e i t h e r because t h e r e i s a p h y s i c a l reason t o f a v o r c e r t a i n s t a t e s or because t h e r e i s some mental r e a s o n . G e n e r a l systems laws a r e based on l o g i c , and l i k e m a t h e m a t i c a l arguments, they cannot be t r u e or f a l s e , o n l y ' v a l i d ' or ' i n v a l i d . ' B. P r o c e d u r e O u t l i n e a. Overview So c a l l e d 'systems a n a l y s i s ' t e c h n i q u e s a r e a p p l i e d t o a g r e a t many, t o t a l l y d i f f e r e n t k i n d s of problems. A l t h o u g h the o u t l i n e s of the p r o c e d u r e s seem s u p e r f i c i a l l y t o be c o m p l e t e l y u n r e l a t e d , c l o s e r e x a m i n a t i o n r e v e a l s a v e r y c l e a r p a t t e r n ( T a b l e 3 ) , which has been put i n t o a f l o w c h a r t ( F i g u r e 17). 1 54 T a b l e 3. Steps In Systems A n a l y s i s H a r r i s b e r g e r (1966) H i c e et a l . (1974) D e f i n i n g - p r o b l e m S e e k i n g I d e a t i o n - c r e a t i v i t y S y n t h e s i s - p a r a m e t e r s D e f i n e d O p t i m i z a t i o n - d e c i s i o n s Deta i 1 i n g - d e v e l o p m e n t Testing-improvement D e f i n e Problem D e f i n e System O b j e c t i v e s Set Performance C r i t e r i a Determine I n p u t s , Outputs, E v a l u a t e S e l e c t Approach D e N e u f v i l l e and S t a f f o r d ( 1 9 6 8 ) Chestnut (1965) D e f i n e O b j e c t i v e s Measures Of E f f e c t i v e n e s s Generate A l t e r n a t i v e s E v a l u a t e A l t e r n a t i v e s S e l e c t S o l u t i o n F o r m u l a t e S y n t h e s i z e D e s i g n Measure Compare Recycle Objectives Recycle A l t e r n a t i v e s Problem Formulation iF Objectives Defined Measures of Effectiveness Generate A l t e r n a t i v e s Evaluate A l t e r n a t i v e s Solution(s) S e l e c t i o n Design D e t a i l s Write - Up Compile L i t e r a t u r e I Compile Design D e t a i l s Figure 17. Flowchart of systems analysis procedure. 1 56 Three main c h a r a c t e r i s t i c s a r e h e l d i n common. The f i r s t i s t h a t a sequence i s f o l l o w e d . T h i s i s : 1. D e f i n e the s i t u a t i o n , 2. D e f i n e the o b j e c t i v e s , 3. Generate p o s s i b l e s o l u t i o n s , 4. E v a l u a t e the p o s s i b l e s o l u t i o n s . 5. Make a d e c i s i o n . The second c h a r a c t e r i s t i c i s t h a t the p r o c e s s i s i t e r a t i v e . A f t e r the f i r s t time through the sequence, the s i t u a t i o n and o b j e c t i v e s a re c l a r i f i e d . The second, t h i r d and so on ti m e s t h r o u g h the sequence are i n response t o the i n c r e a s e d i n f o r m a t i o n t h a t i s a v a i l a b l e a f t e r the f i r s t t i m e . There may be some m i s c o n c e p t i o n i n the f i r s t r u n - t h r o u g h t h a t i s c l e a r e d up i n the second, or the second may be a more d e t a i l e d l o o k a t a p o r t i o n or p o r t i o n s of the p o s s i b l e s o l u t i o n g e n e r a t e d by the f i r s t . T h e r e f o r e the d e c i s i o n made can be: 1. To c a r r y out c e r t a i n recommendations; 2. To go back and redo the a n a l y s i s under b e t t e r d e f i n e d c o n d i t i o n s ; 3. To c o n t i n u e a t a more d e t a i l e d l e v e l o r ; 4. To drop the whole s u b j e c t i f g r o s s i n c o n s i s t e n c i e s or a c o m p l e t e l y n e g a t i v e s o l u t i o n a re the outcomes. The t h i r d c h a r a c t e r i s t i c i s t h a t the s t r a t e g y of systems a n a l y s i s i s t o d e a l w i t h l a r g e complex problems by b r e a k i n g them down i n t o many subcomponent, s m a l l , r e l a t i v e l y s i m p l e r problems (Koberg and B a g n e l l , 1981) 1 57 b. Problem D e f i n i t i o n The s i t u a t i o n which c a l l s f o r a systems a n a l y s i s i s o f t e n v e r y o b v i o u s . P a r t i c u l a r l y i f the a n a l y s i s i s t o be done t o h e l p c l a r i f y the problem, i t may seem i l l o g i c a l t o say t h a t the problem must be c l a r i f i e d b e f o r e i t can be c l a r i f i e d . Management g u i d e s , however, spend a g r e a t d e a l of time i n showing how t o see what s h o u l d be o b v i o u s . Most o f t e n any problem i s w e l l i n termeshed w i t h o t h e r problems, r e l a t e d or n o t , such t h a t t h e i r i n d i v i d u a l i t i e s cannot r e a d i l y be seen. Such problem d e f i n i t i o n can be c o n s i d e r e d as the f i r s t i n v e s t i g a t i v e c y c l e of the systems a n a l y s i s sequence, or can be c a l l e d a ' p r e f o r m a l a n a l y s i s . ' I t s o b j e c t i v e s are t o g i v e a f i r m b a s e l i n e from which the e n s u i n g systems a n a l y s i s can p r o c e e d . A f t e r the f i r s t i t e r a t i o n of the sequence, s u c c e e d i n g problem d e f i n i t i o n s stem from the d e c i s i o n made at the end of the l a s t i t e r a t i o n . There w i l l always be problems to s o l v e a f t e r d e c i s i o n s have been made; p o s i t i v e d e c i s i o n s l e a d t o more d e t a i l e d problems; n e g a t i v e d e c i s i o n s l e a d t o a c l e a r e r r e d e f i n i t i o n of p r e v i o u s problems such t h a t f u t u r e work, whether i t i s f o r e s e e n or n o t , can b e n e f i t from the a n a l y s i s . c. O b j e c t i v e s Any p a r t i c u l a r problem i s g e n e r a l l y a p a r t of some l a r g e r problem, and i s made up of s e v e r a l s m a l l e r problems. The purpose of s t a t i n g the o b j e c t i v e s , once the g e n e r a l environment has been e s t a b l i s h e d i n the problem d e f i n i t i o n , i s t o d e c i d e 158 c l e a r l y what range and scope w i l l bound the a n a l y s i s . Any a n a l y t i c a l endeavor can c o n t i n u e v i r t u a l l y ad i n f i n i t u m , thus i t i s i m p o r t a n t which outcomes w i l l be c o n s i d e r e d as s i g n a l s t o s t o p and which w i l l be s i g n a l s t o go on. The v a l i d i t y of u s i n g c l e a r l y s t a t e d o b j e c t i v e s as g u i d e l i n e s has found wide r a n g i n g a c c e p t a n c e i n many f i e l d s of modern t h i n k i n g . Mager (1972) recommends c l a r i f y i n g the g o a l s of the a n a l y s i s by w r i t i n g down the o b j e c t i v e s which a r e d e r i v e d from the g o a l , s t a t e d as p o s i t i v e performance outcomes. Gronlund (1970) agrees by a s s e r t i n g t h a t o b j e c t i v e s s h o u l d always be w r i t t e n as s h o r t s t a t e m e n t s s t a r t i n g w i t h a c t i v e v e r b s which s t a t e measureable c r i t e r i a and c o n d i t i o n s . The purpose i s t o f a c i l i t a t e r e c o g n i t i o n of su c c e s s or f a i l u r e i n meeting the o b j e c t i v e s . A u s e f u l way t o keep account of complex, m u l t i - f a c e t e d outcomes i s t o o u t l i n e a s u i t a b l e s e t of measures of e f f e c t i v e n e s s t o e v a l u a t e d e s i g n a l t e r n a t i v e s . The measures must a l s o be e v a l u a b l e on some r e c o g n i z a b l e s c a l e , whether t h a t s c a l e i s nominal (yes or no, a c c e p t a b l e or u n a c c e p t a b l e ) , o r d i n a l (ranked i n o r d e r of d e s i r a b i l i t y ) , i n t e r v a l ( r a n k i n g on an a r b i t r a r y s c a l e of numbers), or r a t i o (measurable e n t i t i e s on a b s o l u t e s c a l e s ) . M u l t i p l i e r f a c t o r s may be a p p l i e d t o d i f f e r e n t measures t o i n d i c a t e t h e i r r e l a t i v e v a l u e s . I t i s imp o r t a n t t o s t a t e t h e s e measures a p r i o r i , t o a v o i d b i a s d u r i n g e v a l u a t i o n . 1 59 d. A l t e r n a t i v e G e n e r a t i o n The most o b v i o u s way t o come up w i t h a s e t of a l t e r n a t e s o l u t i o n s t o any problem i s t o t h o r o u g h l y i n v e s t i g a t e how s i m i l a r problems have been s o l v e d by o t h e r s . O f t e n , however, more c r e a t i v i t y i s d e s i r e d i f the s i t u a t i o n i s new or the s t a n d a r d s o l u t i o n s a r e o b s o l e t e . T h i s need f o r c r e a t i v i t y i n d e s i g n has f o s t e r e d the outbreak of a p l e t h o r a of mold b r e a k i n g t e c h n i q u e s i n c r e a t i v e d e s i g n ( i . e . L a t e r a l T h i n k i n g , DeBono, 1973). H a r r i s b e r g e r (1966) o u t l i n e s some r e a s o n a b l e group and i n d i v i d u a l methods f o r g e n e r a t i n g d e s i g n a l t e r n a t i v e s , i n c l u d i n g the t r i g g e r word, c h e c k l i s t , a t t r i b u t e s e e k i n g , Gordon ( u n d e r l y i n g c o n c e p t ) , b r a i n s t o r m i n g , and m o r p h o l o g i c a l c h a r t t e c h n i q u e s . V i s u a l c h a r t i n g methods a r e v e r y u s e f u l i n c a p t u r i n g and o r g a n i z i n g i n s p i r a t i o n s . The webb c h a r t l i n k s randomly b r a i n s t o r m e d system components t o one a n o t h e r . I n p u t -output diagrams h e l p d e f i n e the system i n terms of i t s most b a s i c f u n c t i o n s and r e l a t i o n s , congruent w i t h the s t r a t e g y of systems a n a l y s i s t o break the o v e r a l l system down i n t o s m a l l , h a n d l e a b l e subsystems. e. A l t e r n a t i v e E v a l u a t i o n A l t e r n a t i v e e v a l u a t i o n , b e i n g the essence of the a n a l y s i s , i s t he most complex and c o n f u s i n g p a r t of most systems a n a l y s e s . Many m i n i a n a l y s e s a r e performed i n the g u i s e of e v a l u a t i o n - - m a s s b a l a n c e , economic, c o s t b e n e f i t , e t c . For a stud y which c l e a r l y has s t a t e d i t s o b j e c t i v e s and s o l i d i f i e d 1 60 the scope of the study through l i s t i n g measures of e f f e c t i v e n e s s , the e v a l u a t i o n need o n l y i n c l u d e a l i s t of the v a l u e s a c h i e v e d by each a l t e r n a t e d e s i g n i n response t o the measures of e f f e c t i v e n e s s . The a n a l y s i s i s q u i t e s t r a i g h t f o r w a r d up u n t i l t h i s p o i n t s i n c e i t i s concerned w i t h b r e a k i n g the system i n t o p i e c e s . In the e v a l u a t i o n , however, the system must e v e n t u a l l y be measured as a whole. A p r o l i f i c a l t e r n a t i v e g e n e r a t i o n w i l l g e n e rate too many t o t a l systems t o p l a u s i b l y be e v a l u a t e d i n d i v i d u a l l y , t h e r e f o r e i t i s a d v i s a b l e t o e v a l u a t e the s u b a l t e r n a t i v e s , based on r e l a t e d r e s e a r c h as the 'best' judgement a v a i l a b l e , and then re-assemble the subcomponents i n t o a l t e r n a t e wholes. There a r e some r i s k s i n t h i s approach, s i n c e the be s t o v e r a l l system may indeed c o n t a i n some l i n k s which a r e c o n s i d e r e d weak i f o n l y ranked from a narrow v i e w p o i n t and some s u b j e c t i v e judgement i s needed when the ' o p t i m a l ' subcomponents are re-assembled. f. D e c i s i o n As mentioned, the aim of the a n a l y s i s i s t o l e a d up t o a s i t u a t i o n where the be s t i n f o r m e d d e c i s i o n can be made w i t h r e g a r d t o the a n a l y s i s o b j e c t i v e s . D e c i s i o n a n a l y s i s i s a s c i e n c e i n i t s e l f (Brown, e t a l . , 1974) and can be h i g h l y q u a n t i t a t i v e or s i m p l y be s u b j e c t i v e judgements made a f t e r a c e r t a i n number of r e l e v a n t d a t a have been c o l l e c t e d . The d e c i s i o n t r e e i s a u s e f u l a i d t o c e r t a i n k i n d s of a l t e r n a t i v e s e l e c t i o n . Each parameter l e v e l i s g i v e n a v a l u e , r a t e d i n p r o b a b i l i t y of s u c c e s s or some o t h e r measurable f a c t o r . The 161 best a l t e r n a t i v e i s the one whose t o t a l a c c o u n t i n g i s the h i g h e s t or l o w e s t , depending on the v a r i a b l e s a n a l y s e d , or has the most d e s i r a b l e c o m b i n a t i o n of outcomes from a n a l y s i s of many f a c t o r s . D e c i s i o n s a r e not j u s t made a t the end of the systems a n a l y s i s , but at any time when a f a c t o r p roves t o be i n f e a s i b l e . T h i s c o n t i n u a l e v a l u a t i o n of the o p t i o n s , such t h a t e a r l y e l i m i n a t i o n s of i n c o m p a t i b i l i t i e s and o t h e r n o n - f e a s i b l e s o l u t i o n s , g r e a t l y h e l p s the systems a n a l y s i s d e a l w i t h v e r y broad problems i n a s y s t e m a t i c way w i t h o u t becoming too bogged down e v a l u a t i n g g r e a t numbers of p o s s i b l e s o l u t i o n s . 1 62 6. MODELLING METHODS A. Types of Models Some form of m o d e l l i n g i s a p p l i e d i n almost a l l e v a l u a t i o n p r o c e d u r e s . A model i s "a m a t h e m a t i c a l or p h y s i c a l system, o b e y i n g c e r t a i n s p e c i f i e d c o n d i t i o n s , whose b e h a v i o r i s used t o und e r s t a n d a p h y s i c a l , b i o l o g i c a l or s o c i a l system t o which i t i s analagous i n some way" (Lapedes, 1974). Emsoff and S i s s o n (1970) c a t e g o r i z e t y p e s of models, t h e i r method of p r e d i c t i n g outcomes and l i m i t a t i o n s , as f o l l o w s : Model Type P r e d i c t i o n l i m i t a t i o n s D e s c r i p t i v e P h y s i c a l Symbolic P r o c e d u r a l Judgement Mechan i c a l Mathemat i c a l S i m u l a t i o n Does Not P r e d i c t P r o c e s s No I n f o r m a t i o n Model Needs D e f i n e d E q u a t i o n s P r o p e r t i e s Not E a s i l y Deduced O p t i m i z a t i o n r e f e r s t o the s e l e c t i o n of the be s t s o l u t i o n a t t a i n a b l e w i t h the r e s o u r c e s and time a v a i l a b l e . Types of o p t i m i z a t i o n a r e : 1. I n t u i t i v e ; 2. D i f f e r e n t i a l c a l c u l u s of c o n t i n u o u s f u n c t i o n s ; 3. Extremum f i n d i n g ( l i n e a r programming) o r ; 4. Search ( H i l l i e r and Leiberman, 1974). Models may a l s o be c h a r a c t e r i z e d a s : a. S t a t i c v e r s u s D y n a m i c - - c a l c u l a t i o n s done u s i n g one s e t 163 of parameter v a l u e s or u s i n g a feedback l o o p of changing v a l u e s ; b. Aggregate v e r s u s D e t a i l e d — a c c o r d i n g t o the degree of r e s o l u t i o n or l e v e l of i n d e n t u r e , t h a t i s the number of s m a l l e r and s m a l l e r subcomponents i n t o which the o v e r a l l system i s broken down; c. P h y s i c a l v e r s u s B e h a v i o r a l - - t h e i n c o r p o r a t i o n of p r e d i c t i v e v e r s u s r e l a t i v e l y n o n - p r e d i c t i v e f a c t o r s , d. Computer v e r s u s Human—depends on the mechanism which c a r r i e s out the s i m u l a t i o n , and i t s degree of c o n s i s t e n c y ; e. C o n t i n u o u s v e r s u s D i s c r e t e — r e l a t e d t o the f u n c t i o n s b e i n g e x p r e s s e d as i n s t a n t a n e o u s r a t e s or as r a t e s over c e r t a i n time p e r i o d s , which a r e i t e r a t e d ; f . S i z e of Time Q u a n t a — b e t w e e n c o m p u t a t i o n s ; g. D e t e r m i n i s t i c v e r s u s S t o c h a s t i c — w h e t h e r or not mean v a l u e s r a t h e r than p r o b a b i l i t i e s of o c c u r r e n c e are used. B. M o d e l l i n g P r o c e s s The purpose of m o d e l l i n g i s t o p r e d i c t changes i n the system f o l l o w i n g d e f i n e d p e r t u r b a t i o n s . The m o d e l l i n g p r o c e s s i s v e r y much l i k e t h a t of t h e systems a n a l y s i s , as i s i l l u s t r a t e d by a comparison of T a b l e s 3 and 4. M o d e l l i n g can be c o n s i d e r e d a subcomponent of the t o t a l systems a n a l y s i s , as an a i d i n the e v a l u a t i o n of a l t e r n a t i v e s . The p r o c e d u r e s o u t l i n e d i n T a b l e 4 a r e m o s t l y f o r p r e p a r i n g the system i n f o r m a t i o n f o r m o d e l l i n g on a computer. S i n c e a system's i n t e r a c t i o n s can be 1 64 T a b l e 4. Steps In Computer M o d e l l i n g Emsoff and S i s s o n (1970) A b d u l l a h (1977) F o r m u l a t e Problem F o r m u l a t e Subsystems I d e n t i f y A l t e r n a t i v e s S earch For Best A l t e r n a t i v e s Combine Subsystem Models Program and Debug V a l i d a t e Implement R e s u l t s D i v i d e To Subsystems I d e n t i f y Subsystem Components F l o w c h a r t I n f o r m a t i o n Set M a t h e m a t i c a l D e s c r i p t i o n s Program Subsystems Combine Subsystems Test S e n s i t i v i t y V a l i d a t e W a l t e r s et a l . (1974) Coulman et a l . (1972) Decide Purpose and Scope Choose V a r i a b l e s F l o c h a r t R e l a t i o n s h i p s M a t h e m a t i c a l R e l a t i o n s h i p s Program For Computer D e f i n e Problems S e l e c t Components C h a r a c t e r i z e Components L i n k Components L i n k To Environment 1 65 v e r y complex, i t i s most i m p o r t a n t t o d e f i n e o n l y the most c r i t i c a l subcomponents, which can be c l a s s i f i e d as ( W a l t e r s e t a l . , 1976; K a m i n s k i , 1974): 1. System s t a t e v a r i a b l e s — e n t i t i e s which the model t r i e s t o p r e d i c t ; i n d i c e s of the s t a t e of the system; 2. P a r a m e t e r s - - c o n s t a n t s n e c e s s a r y t o the p r e d i c t i o n s ; 3. D r i v i n g v a r i a b l e s — m a n i p u l a b l e f a c t o r s n e c e s s a r y f o r p r e d i c t i o n ; 4. Rate v a r i a b l e s - - d e t e r m i n e changes; 5. Exogenous e v e n t s — u n c o n t r o l l a b l e o c c u r r e n c e s . A t e c h n i q u e o f t e n recommended i s b r e a k i n g down the system i n t o subsystems which a r e f u r t h e r s u b d i v i d e d i n t o subcomponents. When the lowest denominator l e v e l i s reached, r e l a t i o n s h i p s a r e o u t l i n e d by f l o w c h a r t i n g and d e f i n e d by ma t h e m a t i c a l e q u a t i o n s . These e q u a t i o n s a r e l i n k e d t o g e t h e r i n t o s e q u e n t i a l p r o c e s s i n g s t e p s t o make up the t o t a l model. The model i s v a l i d a t e d by comparing s i m u l a t i o n output w i t h p r e d e t e r m i n e d performance s t a n d a r d s . 166 C. F l o w c h a r t i n g I t may be u s e f u l i n i n t r o d u c i n g f l o w c h a r t i n g t o g i v e a few examples of r e p r e s e n t a t i o n s of p r o d u c t i o n systems. The purpose of f l o w c h a r t i n g i s t o g i v e a v i s u a l r e p r e s e n t a t i o n of the s t a t i c or dynamic r e l a t i o n s h i p s between system subcomponents. V i r t u a l l y a n y t h i n g can be f l o w c h a r t e d . The f l o w c h a r t u s u a l l y r e p r e s e n t s the system as a c o n g l o m e r a t i o n of boxes which are l i n k e d t o g e t h e r by l i n e s . The boxes and l i n e s can r e p r e s e n t many d i f f e r e n t t h i n g s , d i f f e r e n t shaped boxes and l i n e s b e i n g used t o c l a r i f y the k i n d s of subcomponents and i n t e r r e l a t i o n s h i p s . Leung, and Mi (1977) p r e s e n t a g r a p h i c a l model of a g e n e r a l i z e d a n i m a l p r o d u c t i o n system model ( F i g u r e 18) which d e s c r i b e s a computer model i n GPSS s i m u l a t i o n program l a n g u a g e ) . R e l a t e d t o a q u a c u l t u r a l systems, t h i s shows the g e n e r a l r e l a t i o n s h i p between the s t o c k , b r e e d i n g , r e a r i n g and m a r k e t i n g p r o c e s s e s i n an o p e r a t i o n . In m o d e l l i n g l o b s t e r growth, S c h n e i d e r (1974) d e s c r i b e s , g r a p h i c a l l y , the f a c t o r s a f f e c t i n g growth r a t e a t each i n d i v i d u a l molt l e v e l i n the l o b s t e r ' s l i f e h i s t o r y ( F i g u r e 19). E u s i b i o , et a l . (1976) d e s c r i b e t h e i r multicomponent p i g -f i s h - p l a n t s - m e t h a n e p r o d u c t i o n system ( F i g u r e 20) i n terms of s i m p l e web c h a r t type r e l a t i o n s h i p s . A l l e n and Johnson's (1976) l o b s t e r c u l t u r e system ( F i g u r e 21) i s diagrammed w i t h r e g a r d t o water f l o w t h r o u g h the system. P r i t c h a r d (1976) t a k e s a v e r y macroscopic v i e w p o i n t i n 167 INITIAL \<S-gTOCKING y N he no 0?^ £j BREEDING & ' GESTATION FACILITY yes <3>H no 0; too old A: abortion LATE GESTATION FACILITY , PASTUHITION j FACILITY I 1 NURSING m o t h e * > FACILITY young animal GROWING FACILITY I I 1 F GROWING ACILITY I I GROWING FACILITY III Y yes reeding j "[female re-I placement Simulation flow diagram of the Generalized Animal Production System F i g u r e 18. D e c i s i o n f l o w c h a r t ( f r o m Leung and Mi, 19 77) FDCD pf\EDi\roR V TOTAL POPULATION a MDRMLI7Y l _ v 1 System illustrating factors affecting l i f e processes of a lobster population. Figure 19. Line drawing flowchart(from Schneider, 1974). 169 C H L O R E L L A BASIC NEEDS TJie Recycling Process Figure 20. Multi-component system of Eusibio et al . C 1 9 7 6 ) Rawing Unit. C m n l anaVar IMItMual CaMakMra a« V«IMI f l iaa Waala Traatflval ta EiwfrawwaWally Maa,»M4 L r a l Waal* Trastflwrt aaa O a « f * M l t M I. BMatfcallr Aaaiitnri Laval Schematic production system for intensive aquaculture. Figure 21. Water flow flowchart, from Allen and Johnston( 19 76 ). VALUES Food Rural Development Resource UM Worth Employment Recreation Foreign Aid Strategies Tactics (Operations) Possible Activities (Feasibilities) Modular aquaculture. U u of heated effluent. Market impacts, etc 4 I I Program coordination. Workshops. PUnrung seminars. Technical intelligence Actual Activities *W«U a, Species selection. Ufe habits. Growth Laboratory screening,. Site availability Reproduction studies. Physiology. Diseases etc s A *4 I I _1_ Obiectives and Priorities Systemic Variables PJot-scale Bioenergetics. Cost accounting Product acceptability. Puce elasticity, ate I I _ 1 _ Disease Regulations. Zoning Protect-on of Technology Assistance programs, ate Efficient (Input Ononied) Measures Design ol enterprise, cost benefit analysis Ocptoymen. of Resources A I l Operations Commercial Aquaculture. Administrative Biological and Engineering Sciences Forecasting - —Planning - -£> Decisionmaking -Organisation — R a t i o n a l Creative Action Structured aquaculture development. F i g u r e 22. I n s t i t u t i o n a l o r g a n i z a t i o n a n d p l a n n i n g f l o w c h a r t ( P r i t c h a r d , 1 9 171 r e l a t i n g the v a r i o u s components a f f e c t i n g an i n d u s t r y wide a q u a c u l t u r e p o l i c y ( F i g u r e 2 2 ) . These are a l l v e r y s i m p l e r e p r e s e n t a t i o n s of the systems they d e s c r i b e . More h i g h l y r e f i n e d f l o w c h a r t i n g methods have been dev e l o p e d f o r more q u a n t i t a t i v e use, u s i n g a l a r g e r v a r i e t y of symbols which have more s p e c i f i c meanings t o b e t t e r c a t e g o r i z e the system components. Computer f l o w c h a r t s a r e of two t y p e s , those r e p r e s e n t i n g the hardware c o n f i g u r a t i o n s and those r e p r e s e n t i n g the s o f t w a r e a l g o r i t h m s (Mehra, 1965). A d a t a h a n d l i n g p r o c e d u r e i s d e f i n e d w i t h r e g a r d t o the v a r i o u s computer d e v i c e s used i n the a c q u i s i t i o n , p r o c e s s i n g and p r e s e n t a t i o n of i n f o r m a t i o n , u s i n g s p e c i f i c symbols f o r p a r t i c u l a r d e v i c e s . The a l g o r i t h m f l o w c h a r t ( i . e . F i g u r e 23) f o l l o w s the sequence of l o g i c used t o p r o c e s s the d a t a , the o p e r a t i o n s b e i n g d e f i n e d by symbols r e p r e s e n t i n g the s t e p s of l o g i c taken i n a t t e m p t i n g t o s o l v e a problem. PERT (Program E v a l u a t i o n and R e t r i e v a l Technique; B a r n e t s o n , 1962) i s a f a m i l y of t e c h n i q u e s used i n the p l a n n i n g and e x c e c u t i o n of systems. In t h i s case i t i s not so much the boxes, r e p r e s e n t i n g the b e g i n n i n g of t a s k s , which are i m p o r t a n t , but the ar r o w s , r e p r e s e n t i n g the d u r a t i o n of the t a s k s . As the c h a r t i s p l a n n e d , the t i m i n g of o p e r a t i o n s i s c l a r i f i e d and when the c h a r t i s c o n s t a n t l y up-dated as system i m p l e m e n t a t i o n goes on, p r o g r e s s i n each o p e r a t i o n i s m o n i t o r e d . A v e r y i m p o r t a n t f u n c t i o n of the c h a r t i s t o p o i n t out the C r i t i c a l P a t h , a l o n g which any d e l a y causes a d e l a y i n 172 Oisploy "Tarqol WiiaM Cannot Bv Ranched" •nd Valwi oi Assumption* From Olse Flics Compvlo Voluss Oisploy Instruct loi Oisploy (1) Tatlot (2) Assumptions Modify (1) Tobiss (2) Assuniptions Inilialit* Cosl snd Performance Variables, Sot Toroet Weltjnl Output Units Cslculsto All Costs Print Results Calculate Flowrale Aorotlon ft*q«*r«m»nt to Moot Oeoian Crilorio Th Limit . Eiceeded . YES Calculato Growth incrvm*** Calculate t*m Par tod, Ptopo ighl at End ol rtion Surviving y/C ont intWMSN. Accwnulalo Wajght in Syalvm. Ar*« Aaquif«d. Ammonia Pro***ction. Oiygan ConatjnMd. f ••C-Conatimad Calculate and Sum (1) P«*d ConaumplioA (2) Ammonia Production ( 3 ) Oiygon Coraumption F i g u r e 23. Computer program a l g o r i t h m f l o w c h a r t (from A l l e n and Jo h n s t o n , 19 76). 173 the whole o p e r a t i o n , and the subcomponents of which r e c e i v e h i g h p r i o r i t y t r e a t m e n t . The PERT can be done a t a v e r y h i g h l e v e l of a g g r e g a t i o n ( F i g u r e 24) of i n some d e t a i l ( F i g u r e 25). O p e r a t i o n p r o c e s s c h a r t s c a t e g o r i z e the k i n d of o p e r a t i o n s d e a l t w i t h i n PERT, a g a i n as a t o o l i n d e s i g n and i n c a r r y i n g out the f u n c t i o n of systems. Systems dynamics i s a k i n d of c o n t i n u o u s s i m u l a t i o n t e c h n i q u e d e v e l o p e d by F o r r e s t e r (1968), which has i t s own d i s t i n c t f l o w c h a r t i n g symbols, r e p r e s e n t i n g the t y p e s of subcomponents found i n s i m u l a t i o n m o d e l l i n g . Pugh (1976) adapted t h i s approach t o the DYNAMO computer language. C a l l a g h a n et a l . (1977) demonstrate t h i s t e c h n i q u e i n an a p p l i c a t i o n t o a q u a c u l t u r e d e s i g n e v a l u a t i o n . —Program evaluation and review technique (PERT) network. TASKS 1. Demand 2. Supply 3. Price 4. Life history 5. Environmental requirements 6. Culture systems 7. Preservation & processing systems 8. Marketing systems 9. Seed 10. Feed 11. Mortality control 12. Genetic Improvements 13. Space availability 14. Permits & licenses 15. Effluent control methods & cost 16. Labor supply 17. Investment capital 18. Prototype testing 19. Economic analysis 20 . Information dissemination 21 . Production 22. Long-term research F i g u r e 2 4 . P l a n n i n g PERT o u t l i n i n g a q u a c u l t u r a l development i n the U. S. A.(from Glude, 19 77). 175 F i g u r e 25. O u t l i n e and d e t a i l e d PERT(from S p a r r e , 19 76) used i n the management o f a Danish t r o u t farm t o d e c i d e the a l l o c a t i o n o f l o t s o f f i s h . 176 IV. RESULTS 177 7. SITE CHARACTERISTICS A. L o g i s t i c s The s i t e chosen f o r t h i s case study d e s i g n of an a q u a c u l t u r e f a c i l i t y i n the B. C. i n t e r i o r i s the Guichon Ranch on the n o r t h end of N i c o l a Lake ( f i g u r e 2 6 ) . The ranch h e a d q u a r t e r s are l o c a t e d on P r o v i n c i a l Highway #3, a p p r o x i m a t e l y 35 m i l e s south of Kamloops and 20 m i l e s n o r t h of M e r r i t t . The ranch has a p p r o x i m a t e l y 12,000 a c r e s of owned l a n d w i t h l e a s e s e x t e n d i n g t h a t s i z e t o about 60,000 a c r e s ( F i g u r e 27). About 800 a c r e s are under fo r a g e c u l t i v a t i o n but inadequate d i s t r i b u t i o n of w a t er, m a i n l y due t o l a c k of the a p p r o p r i a t e l y s k i l l e d s u r f a c e i r r i g a t i o n manpower, l i m i t s average p r o d u c t i o n t o around 1 ton per a c r e . A l l of t h i s f o r a g e i s used on the ranch f o r w i n t e r f e e d . The ranch p r e s e n t l y s u p p o r t s a herd of about 700 c a t t l e , f e e d i n g on the range or i n p a s t u r e s . S i n c e t h e r e i s no f e e d l o t , t h e r e i s no p a r t i c u l a r a n i m a l waste d i s p o s a l problem. The ranch s u p p o r t s a l a b o u r f o r c e of 4 men most of the y e a r , a l t h o u g h i n peak seasons ( h a y i n g , e t c ) 7 people a r e employed. The ranch has a wide range of machinery and equipment s u i t a b l e t o a l l k i n d s of e a r t h moving, l e v e l l i n g , d i g g i n g , t r a n s p o r t , c o n s t r u c t i o n , plumbing, machinery r e p a i r and maintenance. There a r e s e v e r a l unused b u i l d i n g s i n v a r i o u s s t a t e s of d i s r e p a i r a t v a r i o u s l o c a t i o n s on the r a n c h , remnants of an e r a of more i n t e n s i v e manpower-based f a r m i n g t e c h n i q u e s . 178 F i g u r e 26. L o c a t i o n Map o f t h e Study A r e a 180 The major water source f o r a l l ranch a c t i v i t i e s i s Moore Creek. The c r e e k f l o w i s e n t i r e l y c o n t r o l l e d by a d j u s t a b l e g a t e s on f o u r e a r t h e n s t o r a g e dams a p p r o x i m a t e l y 20 m i l e s upstream from the c r e e k mouth on N i c o l a Lake. These dams were b u i l t by the Guichon C a t t l e Company and thus the water r i g h t s t o the stream b e l o n g s o l e l y t o the r a n c h . I r r i g a t i o n needs are f u l f i l l e d by ' e y e b a l l i n g ' r e q u i r e m e n t s and a d j u s t i n g the s l u i c e g a t e s a c c o r d i n g l y . Depending on i r r i g a t i o n r e q u i r e m e n t s , some of the r e s e r v o i r s may be c o m p l e t e l y emptied d u r i n g the summer. T h e r e f o r e , a l t h o u g h e s s e n t i a l summer water s u p p l y i s a s s u r e d t h r o u g h c o n t r o l of d i s c h a r g e from the r e s e r v o i r s , i n dry y e a r s t h e r e may be v e r y l i t t l e e x c e s s water a v a i l a b l e by l a t e summer. The d i s c h a r g e from Moore Creek v a r i e s c o n s i d e r a b l y throughout the y e a r . L o r z and N o r t h c o t e (1965) r e p o r t e d a h i g h of 240,000 l i t e r s / m i n u t e i n May and a low of l e s s than 6,000 1/min i n August of 1959, a 'dry' y e a r . The Water Survey of Canada ( I n l a n d Waters D i r e c t o r a t e , 1980, see T a b l e 5) have p u b l i s h e d some l i m i t e d d a t a on Moore Creek f l o w s . MacDonald (1975 r e p o r t e d t h a t the s u r f a c e i r r i g a t i o n s u p p l y c a n a l c a p a c i t y i s 2,100 1/min. S i n c e a r e l a t i v e l y s t a b l e f l o w was i n t r o d u c e d t o the stream, Kokanee salmon have e s t a b l i s h e d a spawning ground i n the lower 2 Km of Moore Creek ( L o r z and N o r t h c o t e , 1965). The p o p u l a t i o n of the s u r r o u n d i n g a r e a of B. C. (the p r o s p e c t i v e market s i z e ) i s almost 300,000 p e o p l e , c o n s i d e r i n g t h a t t r a n s p o r t t o the Thompson, N i c o l a and Okanagan r e g i o n s t a k e s l e s s than two hours ( T a b l e 6 ) . TABLE 5. ENVIRONMENTAL DATA FOR THE ADORE CREEK AREA. JANUARY FEBRUARY MARCH APRIL KAY JUNE JULY AUGUST SEPIEMBR OCTOBER NOVEMBER DECEMBER MINIMUM MAIMUH MEAN TOTAL AIR TEMPERATURE: CO -MEAN DAILY HAI1MUM. -2.7 ' J 8.1 13.5 18.6 21.8 26.2 25.1 20.8 13.8 4.6 .2 -2.7 26.2 12.75 -MEAN DAILY MINIMUM. -10.8 -6.4 -3.5 .2 4.3 8.1 9.7 9.1 5.5 1.4 -J.8 -7.4 -10.8 9.7 0.53 -DAILY MEAN. -4.8 -1.7 2.3 6.9 11.5 IS 18 17.1 13.1 7.7 .4 -3.6 -6.8 18 6.66 -STANDARD DEVIATION OF MEAN 4.1 2.9 1.3 1.3 1.1 1.6 1.2 1.6 1.5 1.1 2.2 3.7 -EUREHE HAI1HUK 13.3 14.4 21 30.6 32.8 35.6 38.9 36.7 32.8 30.S 21.7 18.5 38.9 -EITREHE MINIMUM -40 -27.8 -28.4 -8.3 -4.4 -.6 1.7 0 -6.7 -15 -24.4 -42.8 -42.8 PRECIPATION -MEAN RAINFALLIHMI 12 IO.S 7.4 8.4 21.8 23.7 14 23 19.3 17.4 19.6 12.2 7.4 23.7 15.78 189.3 -MEAN SNONFALLtCH) 32.5 13.9 7.2 2.3 .5 0 0 0 .8 1.2 13.2 28 0 32.5 8.30 99.6 -TOTAL PRECIPATION (MM) 50.6 27.2 14.5 10.3 22.4 23.7 14 23 2.1 20.5 35.4 43.8 2.1 50.6 24.13 289.5 -STANDARD DEVIAI'N OF TOTAL 24.7 21.1 11.4 10.4 12.9 17.3 9.4 20.1 14.1 8.9 20.4 26.6 -6REAIESI DAILY RAIN (CN) 21.1 13 16.8 9.1 13.5 19.3 14.2 20.6 27.2 10.8 18.2 22.6 27.2 -GREATEST DAILY SNON INN) 31.2 18.5 11 7.4 6.2 0 0 0 10.2 15.2 20.9 27.4 31.2 -GREATEST PRECIPATION IHMI 31.2 I8.S 16.8 9.1 13.5 I9.J 14.2 20.6 27.2 IS.2 34.9 27.4 34.9 247.9 DE6REE DAYS -ABOVE 18' C 1.5 13.1 46.1 33.6 3.3 .2 0 46.1 97.8 -ABOVE 10' C .6 7.4 66.9 148.4 247.3 220.2 105.3 19.8 .7 .3 0 247.3 816.9 -ABOVE 5' C J.l 4.4 17.3 79 204.8 307.9 405.5 381.7 24B.6 102.6 12.4 4 3.1 405.5 1771.5 -ABOVE 0' C 28.1 43 104.7 216.2 359.7 457.5 560.4 536.3 J97.6 242.4 72.6 36.5 28.1 560.4 3055 -BELOW 0' C 215 84.4 32.9 1.3 55.2 136.4 0 215 527.2 SOLAR RADIAIONISUHMERLAND) (HEGAJOULES/SO.H) -HORIZONTAL(O'l 3.44 4.48 11.54 16.64 20.82 22.64 23.68 19.55 14.47 8.45 3.82 2.5 2.5 23.68 12.84 -STANDARD DEVIAT'N OF 0' .44 .78 1.15 1.34 1.86 1.86 1.08 2.11 1.46 .86 .36 .24 - AT 10' 4.39 8.09 13.32 17.57 19.91 22.06 24.38 21.35 16.54 9.92 4.61 3.18 3.18 24.38 13.78 - AT 30 5.S8 10.32 15.67 18.83 15.99 18.69 23.97 22.3 18.98 12.37 5.99 4.26 4.26 23.97 14.44 - AT 50 4.85 11.59 16.5 18.29 10.69 13.67 21.54 21.14 19.33 13.6 6.82 4.97 4.97 21.54 13.75 - AT 60 7.1 11.8 16.32 17.36 7.78 10.73 19.54 19.77 18.82 13.71 7 5.15 5.15 19.77 12.92 - AT 70 7.1? 11.73 15.73 14.02 6.31 8.41 17.12 17.92 17.83 13.46 7 5.2 5.2 17.92 11.99 - AT ao 7.1 11.38 14.76 14.31 5.36 7.15 14.49 15.68 16.4 12.87 6.83 5.14 5.14 14.4 10.96 BRIGHT SUNSHINE IHOURS) - AT KAMLOOPS 58 93.4 145.6 19B.4 252 255.9 315.7 280 194.7 135.7 70.5 47.7 47.7 315.7 170.65 2047.8 - AT SUMMERLAND 49.1 83.4 148.9 198.7 24. a 261.7 320.6 277.1 206.4 140.6 63.6 39.8 24.8 320.4 151.24 1614.9 HATER FLOW ICU.N/SEC) -MOORE CR. .297 2.01 .796 .226 .094 .078 .125 0 2.01 0.30 3.626 -NICOLA R. (UPPERI .58 .785 .742 1.51 16.6 16.3 4.83 1.37 .014 .488 .714 .572 .488 16.6 3.78 45.305 WATER TEMPERATURE I'CI -NICOLA R(UPPER) .2 .5 3.6 4.4 8.5 12 15 16.2 14 6 2 1 .2 16.2 7.13 -NICOLA RIHERRITI) .35 .a 2.4 5.5 7.4 11.5 14.7 17.5 14 6 4.4 1 .35 17.5 7.13 DATA FROM CANADIAN CLIMATE NORMALS, 1982 182 T a b l e 6 . P o p u l a t i o n Of M a r k e t A r e a C e n s u s U n i t 1 9 7 6 1 981 A s h c r o f t 2 , 0 3 2 2 , 1 56 C a c h e C r e e k 1 , 0 7 4 1 , 308 K a m l o o p s 5 8 , 3 1 1 6 4 , 0 4 8 L o g a n L a k e 1 , 3 8 8 2 , 6 3 7 Me r r i 11 5 , 6 8 0 6 , 1 1 0 T o t a l T h o m p s o n - N i c o l a 9 2 , 126 1 0 1 , 9 8 3 K e l o w n a 5 1 , 9 5 5 5 9 , 1 9 6 P e a c h l a n d 2 , 2 8 6 2 , 8 6 5 T o t a l C e n t r a l O k a n a g a n 7 1 , 2 5 4 8 5 , 2 3 7 A r m s t r o n g 2 , 2 6 0 2 , 6 8 3 C o l d s t r e a m 4 , 9 9 5 6 , 4 5 0 V e r n o n 1 7 , 6 7 8 1 9 , 9 8 7 T o t a l N o r t h O k a n a g a n 4 6 , 8 6 0 5 4 , 3 5 2 P e n t i c t o n 2 1 , 4 0 7 2 3 , 1 8 1 P r i n c e t o n 3 , 1 3 2 3 , 0 5 1 T o t a l O k a n a g a n - S i m i l k a m e e n 51 , 5 2 0 5 7 , 185 GRAND TOTAL 2 6 1 , 8 6 0 2 9 8 , 7 5 7 183 B. E n v i r o n m e n t a l No r e l i a b l e d ata e x i s t on y e a r - r o u n d t e m p e r a t u r e , pH, ha r d n e s s , c o n d u c t i v i t y or t u r b i d i t y . Summer tem p e r a t u r e s were r e p o r t e d by L o r z and N o r t h c o t e (1965) as r e a c h i n g d a i l y peaks of 14-16°C i n August of 1958 and 1959, d r o p p i n g 1.0-2.5°C a t n i g h t . Mean d a i l y a i r t e m p e r a t u r e s from A p r i l t o October a r e 5.5°C or h i g h e r and rea c h 20°C i n J u l y , the mean peak d a i l y t e m p e r a t u r e s r e a c h i n g 25°C (MacDonald, 1975). For the purposes of t h i s s t u d y , i t w i l l be assumed t h a t due t o i t s l o c a t i o n and the i n d i g e n o u s f i s h p o p u l a t i o n and compared w i t h o t h e r streams i n the a r e a , the c h e m i c a l parameters of Moore Creek would be c o n d u c i v e t o the c u l t u r e of f i s h . The f l o w r a t e i s a r t i f i c i a l l y c o n t r o l l e d , and t h e r e f o r e poses no problem o t h e r than an e s t i m a t i o n of r e s e r v e s . There i s a l s o no m e t e o r o l o g i c a l d a t a a v a i l a b l e f o r the s i t e , a l t h o u g h the a i r p o r t a t Kamloops, 50 k i l o m e t e r s t o the n o r t h i n a s l i g h t l y l e s s a r i d r e g i o n , i s a major p r o v i n c i a l r e p o r t i n g s t a t i o n , and M e r r i t t , 20 k i l o m e t e r s t o the s o u t h , a l s o has a weather s t a t i o n . The N i c o l a V a l l e y i s a s e m i - a r i d r e g i o n r e c e i v i n g an average of 14 i n c h e s of r a i n per year (Rose, 1953). E v a p o t r a n s p i r a t i o n d u r i n g the growing season i s 31.4 i n c h e s and r a i n f a l l i s o n l y 4.7 i n c h e s , which l e a v e s an i r r i g a t i o n r e q u i r e m e n t f o r a l f a l f a , o a t s , c l o v e r s and g r a s s e s of 27.2 i n c h (Madani, 1976). E n v i r o n m e n t a l d a t a from the Moore Creek a r e a a r e g i v e n i n Ta b l e 2. A i r t e m p e r a t u r e , p r e c i p i t a t i o n and degree days a r e f o r M e r r i t t (Canadian C l i m a t e Program, 1982). S o l a r r a d i a t i o n d a t a 1 84 i s f o r Summerland (Canadian C l i m a t e Program, 1982 and Hay, 1979), the c l o s e s t r e p o r t i n g s t a t i o n . B r i g h t s u n s h i n e hours a r e p r e s e n t e d from both Kamloops and Summerland. These data g i v e a g e n e r a l q u a n t i t a t i v e p r o f i l e of the c l i m a t e of the South C e n t r a l I n t e r i o r of B. C. T h i s a r e a has the g r e a t e s t c l i m a t i c extremes i n the c o u n t r y , w i t h a temperature d i f f e r e n c e from the h o t t e s t hot t o the c o l d e s t c o l d of almost 82°C. S i n c e no data e x i s t f o r water t e m p e r a t u r e s of Moore Creek, d a t a f o r the N i c o l a R i v e r a r e p r e s e n t e d as a s u b s t i t u t e ( I n l a n d Waters D i r e c t o r a t e , 1977). Temperature p r o f i l e s a r e p r o b a b l y v e r y s i m i l a r f o r the two r i v e r s , s i n c e they both emerge i n s h a l l o w l a k e s of about the same l a t i t u d e and f l o w a s i m i l a r d i s t a n c e s o u t h t o N i c o l a Lake. 185 8. SYSTEMS ANALYSIS A. Problem Def i n i t i o n The g e n e r a l problem f o r m u l a t i o n f o r the t h e s i s work was g i v e n i n the I n t r o d u c t i o n (Chapter 1 ) . T h i s s e c t i o n w i l l d e a l i n s l i g h t l y more d e t a i l w i t h d e f i n i n g the problem t o be c o n s i d e r e d by t h i s systems a n a l y s i s . The Guichon Ranch appears s u p e r f i c i a l l y t o have some p r o p e r t i e s which c o u l d be c o n s i d e r e d c o n s t r a i n t s t o a q u a c u l t u r e and o t h e r s which may be b e n e f i c i a l to development. The major c o n s t r a i n t s a r e i t s demographic and i t s c l i m a t i c l o c a t i o n s . D i s t a n c e from l a r g e markets adds the expense of f u r t h e r t r a n s p o r t t o the o p e r a t i n g c o s t s of any p r o d u c t i o n of p e r i s h a b l e foods on the r a n c h . The n e a r e s t l a r g e market i s Kamloops, 35 m i l e s away or a p p r o x i m a t e l y 40 minutes d r i v i n g t i m e . However i f we compare t h i s t o lower F r a s e r V a l l e y p r o d u c e r s , whose market i s the Vancouver m e t r o p o l i t a n a r e a , we f i n d t h a t a l t h o u g h d i s t a n c e s t o market are comparable, d r i v i n g time i n the lower m a i n l a n d i s c o n s i d e r a b l y l o n g e r . Proper i c i n g of t r a n s p o r t e d f i s h would e a s i l y s u f f i c e f o r the p r o j e c t e d d i s t a n c e s from Guichon's ranch t o markets i n the N i c o l a , Thompson, Okanagan, and Similkameen v a l l e y s , an a r e a w i t h a t o t a l p o p u l a t i o n of almost 300,000. The p r e f e r r e d remote s e t t i n g s of lower m a i n l a n d t r o u t farms i s r e l a t e d t o the maintenance of both a c l e a n , p r i s t i n e water s u p p l y and p r o p e r t y s e c u r i t y . P o a c h i n g and p o l l u t i o n a r e c o n s i d e r e d the t r o u t 186 f a r m e r ' s b i g g e s t l o c a t i o n - r e l a t e d problems, thus the more remote the l o c a t i o n , the b e t t e r . T h e r e f o r e , we do not f o r e s e e any r e a l problem w i t h the demographic l o c a t i o n of the s i t e . The micro-demography, or the e f f e c t of a t r o u t farm on the c a t t l e r anch i t s e l f , may be a more i m p o r t a n t c o n s i d e r a t i o n . E s s e n t i a l l y we are i n t r o d u c i n g a new way of l i f e i n t o an e s t a b l i s h e d s i t u a t i o n , on a l o c a l s c a l e , and such p e r t u r b a t i o n s i n e v i t a b l y cause u n p r e d i c t a b l e r e a c t i o n s , r a n g i n g from o v e r t r e s i s t a n c e t o o v e r z e a l o u s n e s s . As l o n g as the p r i m a r y income i s from c a t t l e r a n c h i n g , the e x i s t i n g a g r i c u l t u r a l o p e r a t i o n s must be g i v e n f i r s t p r i o r i t y i n a l l c a s e s . The o n l y p l a c e t o put a f i s h farm i s out of the way of the r a n c h i n g a c t i v i t i e s . The main e n v i r o n m e n t a l c o n s t r a i n t s have t o do w i t h the water a v a i l a b i l i t y and t e m p e r a t u r e . The system can be s i z e d to meet minimum water f l o w r a t e s but the r e a l l y i m p o r t a n t q u e s t i o n i s : " W i l l the f i s h grow f a s t enough i n the water te m p e r a t u r e s a v a i l a b l e t o the system?" The summer (May-October) tem p e r a t u r e s a r e q u i t e s u i t a b l e f o r f i s h c u l t u r e . The extreme c o l d w i n t e r s p r e c l u d e any y e a r - r o u n d system o t h e r than a s m a l l , r e c y c l i n g , h e a t e d , i n d o o r o p e r a t i o n . MacDonald et a l . (1975) c o n c l u d e d t h a t such a system c o u l d be v e r y f e a s i b l e f o r f r y p r o d u c t i o n . T h e i r system however i s v e r y c a p i t a l i n t e n s i v e and thus not s u i t a b l e f o r the Guichon study a t t h i s s t a g e . More a p p r o p r i a t e i s t o use the Guichon s i t e as a r e a r i n g f a c i l i t y i n the modular co n c e p t o u t l i n e d by Beamish e t a l . (1975), such t h a t f r y produced by Lower M a i n l a n d h a t c h e r i e s a r e r a i s e d t o market s i z e t o meet l o c a l demands. We s h a l l c o n s i d e r t h i s approach as Phase 187 I of the t o t a l s i t e development t o be d e a l t w i t h by t h i s a n a l y s i s and l e a v e f u r t h e r Phases f o r f u t u r e s t u d i e s . P o t e n t i a l a r e a s of b e n e f i t i n u s i n g the Guichon Ranch as a t r o u t farm s i t e i n c l u d e m a i n l y the b e n e f i t s of s h a r i n g the a l r e a d y e x i s t i n g s u pport f a c i l i t i e s f o r the a g r i c u l t u r a l o p e r a t i o n s i n the form of machinery, equipment, b u i l d i n g s , manpower, and e x p e r t i s e . These b e n e f i t s a r e v e r y hard t o q u a n t i f y , s i n c e n a t u r a l l y i n a p r o g r e s s i v e f a r m i n g o p e r a t i o n t h e r e i s as l i t t l e s l a c k time f o r any of t h e s e f a c i l i t i e s as p o s s i b l e , and the time t h a t can be made a v a i l a b l e s t i l l c o s t s the o v e r a l l o p e r a t i o n more, i n terms of f u e l , d e p r e c i a t i o n , upkeep and wages, than i f t h a t time were not used. B. O b j e c t i v e s Def i n e d The g u i d e l i n e s f o r the d e s i g n of an a q u a c u l t u r a l system on the Guichon Ranch, s t a t e d as o b j e c t i v e s , a r e : 1. M a i n t a i n the s t a t u s quo w i t h r e s p e c t t o the a l r e a d y e x i s t i n g a g r i c u l t u r a l p r o d u c t i o n system. T h i s i n v o l v e s the s u b - o b j e c t i v e s o f : a. Do not i n t e r r u p t or i n t e r f e r e w i t h i r r i g a t i o n o p e r a t i o n s ( s c h e d u l i n g or p l a c e m e n t ) ; b. Do not i n t e r r u p t or i n t e r f e r e w i t h machinery o p e r a t i o n s ( h a r v e s t i n g or p l o w i n g ) ; c. Optional--make use of a n i m a l wastes as a waste management a i d . 188 2. Produce a q u a t i c p r o d u c t s i n the form o f : a. F i s h f o r human consumption; b. F i s h or o t h e r a q u a t i c b i - p r o d u c t s f o r o t h e r uses. 3. Be e c o n o m i c a l l y p r a c t i c a l and f e a s i b l e , i n c l u d i n g : a. R e q u i r e a low i n i t i a l c a p i t a l e x p e n d i t u r e , so t h a t the p r o b a b i l i t y of s t a r t i n g such a system, even on a p i l o t p l a n t or p r o t o t y p e s c a l e , i s g r e a t e r ; b. G i v e an o u t p u t which i s r e l i a b l e w i t h i n the bounds of the s i t e c h a r a c t e r i s t i c s , u s i n g the p r i n c i p l e s of c o n s e r v a t i s m i n e s t i m a t i n g d e s i g n c a p a c i t i e s and system c a p a b i l i t i e s ; c. G i v e a r e a s o n a b l e r e t u r n on investment such t h a t both i n i t i a l and c o n t i n u e d investment would be p r o f i t a b l e . C. Measures of E f f e c t i v e n e s s To b e t t e r d e f i n e the outcomes of the a n a l y s i s , c r i t e r i a were e s t a b l i s h e d by which s o l u t i o n s may be e v a l u a t e d and compared. The measures a r e by no means m u t u a l l y e x c l u s i v e . The number i n b r a c k e t s f o l l o w i n g each measure of e f f e c t i v e n e s s i s a r e l a t i v e s c a l e of importance t o the o v e r a l l system e v a l u a t i o n such t h a t : 5 = e s s e n t i a l , 4 = v e r y i m p o r t a n t , 3 = i m p o r t a n t , 2 = not n e c e s s a r y , 1 = t r i v i a l . 189 a . L a c k o f A g r i c u l t u r a l I n t e r f e r e n c e i ) no i r r i g a t i o n i n t e r r u p t i o n ( 4 ) : a n i m p o r t a n t c o n s i d e r a t i o n i n m a i n t a i n i n g t h e s t a t u s q u o o f t h e e x i s t i n g o p e r a t i o n ; i i ) no w a t e r w a s t a g e ( 3 ) : no more w a t e r s h o u l d be u s e d t h a n i s u s e d by t h e i r r i g a t i o n o p e r a t i o n , s i n c e w a t e r i s , t o c e r t a i n d e g r e e , r e l a t i v e l y s c a r c e ; i i i ) no e q u i p m e n t / m a c h i n e r y t i m e c o n f 1 i c t s ( 4 ) : w h e t h e r d u r i n g c o n s t r u c t i o n o r i n o p e r a t i o n t h e r a n c h a c t i v i t i e s m a i n t a i n f i r s t p r i o r i t y o v e r t h e u s e o f r a n c h f a c i l i t i e s ; i v ) no manpower t i m e c o n f l i c t s ( 4 ) : a s i n t h e p r e c e d i n g m e a s u r e , r a n c h h a n d a s s i s t a n c e g i v e n t o t h e f i s h f a r m c a n o n l y be d u r i n g r a n c h s l a c k t i m e s ; v ) w a s t e u t i 1 i z a t i o n ( 2 ) : b o t h t h e a n i m a l w a s t e s p r o d u c e d on t h e f a r m a n d t h e w a s t e s o u t o f t h e f i s h p o n d s a r e r e s o u r c e s w h i c h may be u t i l i z e d ; v i f e r t i l i z a t i o n c o n t r i b u t i o n ( 1 ) : t h e f i s h f a r m 190 e f f l u e n t may be l o a d e d w i t h n u t r i e n t s b e n e f i c i a l t o t h e f o r a g e p r o d u c t i o n . b . D e g r e e o f A q u a t i c P r o d u c t i o n i ) f i s h p r o d u c t i o n ( 5 ) : t h i s may be i n t e r m s o f f i s h b i o m a s s a c c u m u l a t e d f o r t h e a m o u n t o f w a t e r o r f e e d u s e d , o r t h e d o l l a r v a l u e o f t h e p r o d u c t . F o r l o w e r t r o p h i c c u l t u r e t h e a c c u m u l a t i o n o f b i o m a s s i s m o s t i m p o r t a n t ; i i ) a c c e p t a b i l i t y o f p r o d u c t ( 4 ) : t h i s may be t h e m a r k e t a c c e p t a b i l i t y o f t h e f i s h i n t e r m s o f t y p e , s i z e , s e a s o n a l i t y , t a s t e , t e x t u r e , o r o t h e r f a c t o r s w h i c h a f f e c t t h e v a l u e a n d a r e a l t e r e d by d e s i g n c o n f i g u r a t i o n s . S o c i a l a c c e p t a b i l i t y ( l e g a l i t y , e n v i r o n m e n t a n d s o c i a l i m p a c t s ) i s a l s o i m p o r t a n t , a l t h o u g h l e s s s o f o r t h i s s i t e b e c a u s e o f i t s r e m o t e n e s s ; i i i ) r e l i a b i l i t y ( 5 ) : m o s t i m p o r t a n t f o r e c o n o m i c v i a b i l i t y t h a t t h e c u l t u r e s y s t e m w o r k c o n s i s t e n t l y ; 191 i v ) f l e x i b i l i t y ( 4 ) : t h i s i s i n t e r m s o f t h e a b i l i t y t o i n c r e a s e t h e s i z e o f t h e o p e r a t i o n s h o u l d i t p r o v e e f f e c t i v e , o r t h e a b i l i t y t o c h a n g e s u b c o m p o n e n t s s h o u l d c o n d i t i o n s o r f u r t h e r s t u d y w a r r a n t c h a n g e . E c o n o m i c V i a b i l i t y i ) c a p i t a l c o s t ( 5 ) : m o s t i m p o r t a n t t o g e t a n y p r o t o t y p e g o i n g i s f o r i t t o n o t be a v e r y g r e a t f i n a n c i a l b u r d e n ; i i ) o p e r a t i n g c o s t ( 5 ) : t h e d e s i g n m u s t be s t r e a m l i n e d f o r maximum e n e r g y a n d manpower e f f i c i e n c y ; i i i ) r e v e n u e ( 5 ) : t h e o n l y e a r n i n g m e a s u r e , d e p e n d s m a i n l y on t h e d e g r e e o f p r o d u c t i o n a n d on t h e m a r k e t c o n d i t i o n s . 1 92 D. G e n e r a t i o n of A l t e r n a t i v e s a. Framework of A q u a t i c P r o d u c t i o n R e f e r r i n g t o the d i s c u s s i o n i n A q u a c u l t u r a l D e s i g n , t h e r e a r e many f a c t o r s i n o l v e d i n and a f f e c t i n g a q u a t i c p r o d u c t i o n . These can be s e p a r a t e d i n t o the p h y s i c a l components of the system i t s e l f ( d e s i g n c r i t e r i a ) and the e n v i r o n m e n t a l f a c t o r s which determine the l i m i t a t i o n s t o be s e t on p r o d u c t i o n ( o p e r a t i o n a l p a r a m e t e r s ) . R e l a t e d t o the s i t e a t the G u i c h i o n Ranch, we can f l o w c h a r t t h i s i n t o a r e l a t i o n s h i p diagram of major d e s i g n components ( F i g u r e 2 8 ) . These system subcomponents can be f u r t h e r i n d e n t e d and a l t e r n a t i v e c o n f i g u r a t i o n s l i s t e d f o r each l e v e l i n a m o r p h o l o g i c a l c h a r t ( T a b l e 7 ) . E. E v a l u a t i o n of A l t e r n a t i v e s a. T a b u l a r E v a l u a t i o n Overview The a l t e r n a t i v e s may now be e v a l u a t e d w i t h r e s p e c t t o t h e i r performance r e l a t i v e t o the measures of e f f e c t i v e n e s s . Each a l t e r n a t i v e i s g i v e n a performance r a n k i n g (3 = good; 2 adequate; 1 = poor; 0 = u n a c c e p t a b l e ) f o r each measure, based i ,on the i n f o r m a t i o n d i s c u s s e d below and i n the R e l a t e d R e s e a r c h . The sum of the p r o d u c t s of t h i s r a n k i n g t i m e s the v a l u e f o r each measure g i v e a t o t a l r e l a t i v e v a l u e f o r each a l t e r n a t i v e . 193 Source Aerate Filter Heat Conveyance Percent Use Pre-Treatment Food Type Enclosure Type Fish Type Post-Treatment F i g u r e 28. R e l a t i o n s h i p Diagram o f F a c t o r s A f f e c t i n g P r o j e c t P r o d u c t i o n T a b l e 7. M o r p h o l o g i c a l C h a r t of System Components A. Water Source 1. S p r i n g 2. Creek 3. Lake 4. W e l l B. Water Conveyance 1. Stream 2. P i p e s 3. Flumes 4. C a n a l s 5. Ponds C. Water use i ) p e r c e n t use 1. T o t a l 2. P a r t i a l 3. M i n i m a l i i ) p asses 1. S i n g l e 2. R e c y c l e 3. S e r i a l reuse D. P r e t r e a t m e n t 1. F i l t e r or not 2. Heat or not 3. A e r a t e or not E. F i s h type 1. Trout 2. Carp 3. N a t i v e r e d u c t i o n 4. E x o t i c 5. P o l y c u l t u r e F. F i s h e n c l o s u r e 1. Cage 2. E a r t h e n pond 3. C o n c r e t e raceway 4. P l a s t i c raceway 5. Creek 6. S i l o G. F i s h food 1. W i l d n a t u r a l 2. Commercial 3. C u l t u r e d 4. D i r e c t wastes H. Energy source 1. E l e c t r i c i t y 2. F u e l 3. G r a v i t y 4. Wind 5. S o l a r I . Labour i n p u t 1. Low 2. H i g h j . Energy i n p u t 1. Low 2. High 195 A c o m b i n a t i o n of the h i g h e s t s c o r i n g a l t e r n a t i v e s can g e n e r a l l y be c o n s i d e r e d the 'bes t ' s o l u t i o n . Even though o n l y t h o s e measures of e f f e c t i v e n e s s a r e shown whose v a l u e i s d i f f e r e n t f o r the d i f f e r e n t d e s i g n a l t e r n a t i v e s , a t o t a l of 651 i n d i v i d u a l r a n k i n g s was n e c e s s a r y and d i s c u s s i o n of each d e c i s i o n would be p r o h i b i t i v e . The t a b l e e v a l u a t e s over 500 thousand p o s i b l e d e s i g n c o n f i g u r a t i o n s . The most i m p o r t a n t p o i n t s and the recommended a l t e r n a t i v e c h o i c e a r e d i s c u s s e d i n the f o l l o w i n g s e c t i o n . Some of the e v a l u a t i o n s c o n t a i n a more d e t a i l e d second i t e r a t i o n of the d e s i g n and s e l e c t i o n p r o c e s s , r a t h e r than go thr o u g h a l l the c a t e g o r i e s a g a i n . Many of the t o p i c s c o v e r e d i n the R e l a t e d Research a re not e v a l u a t e d i n the t a b l e s . The reason f o r t h i s i s t h a t they a r e e i t h e r i n t e g r a l p a r t s of the a l t e r n a t i v e s d i s c u s s e d , l o g i c a l e x t e n s i o n s of the s o l u t i o n s chosen, p r o c e d u r e s common t o a l l of the d e s i g n a l t e r n a t i v e s , or r e p r e s e n t d e s i g n a l t e r n a t i v e s of near i d e n t i c a l v a l u e . H a r v e s t method depends e n t i r e l y on the f i s h e n c l o s u r e t y p e . P r o c e s s i n g f a c i l i t i e s have a u n i v e r s a l s t a n d a r d of s a n i t a t i o n but t h e i r e x t e n t depends on the p r o d u c t t y p e , which i s d e t e r m i n e d by the f i s h t y pe and market. Sto r a g e r e q u i r e m e n t s , f o r food or f o r p r o d u c t , depend on those c r i t e r i a . B r e e d i n g r e q u i r e m e n t s and methods depend on the f i s h r a i s e d . R e a r i n g c o n d i t i o n s ( t e m p e r a t u r e , pH, f e e d i n g l e v e l , oxygen c o n c e n t r a t i o n , ammonia c o n c e n t r a t i o n ) a r e i n t e r a c t i n g f a c t o r s which a r e always o p t i m i z e d t o produce the f a s t e s t growth r a t e , 196 r e g a r d l e s s of the d e s i g n . They are o p e r a t i n g parameters r a t h e r than d e s i g n a l t e r n a t i v e s . H e a l t h and p o l l u t i o n c o n t r o l both f o l l o w s t a n d a r d g u i d e l i n e s which the d e s i g n type does not s i g n i f i c a n t l y a l t e r but which can be o p t i m i z e d w i t h i n any d e s i g n . The purpose of the f a c i l i t y b e i n g d e s i g n e d i s f o r the g e n e r a t i o n of income, and any s i d e b e n e f i t s from r e s e a r c h i n t o the development of a new t e c h n o l o g y are c o n s i d e r e d secondary. b. Water Source. Even though a groundwater source would be c l e a n e s t and of most c o n s t a n t t e m p e r a t u r e , t h e r e a r e no known h i g h volume s p r i n g s i n the a r e a and development of w e l l s i s e x p e n s i v e . Deep w e l l s are v e r y e x p e n s i v e t o d e v e l o p (average $50,000 each f o r one d r i l l e d f o r Department of F i s h e r i e s and Oceans i n 1979-83) and w e l l l o g s from s h a l l o w w e l l s i n the N i c o l a V a l l e y show sediments of low p o r o s i t y (Hugh L e i b s c h e r , 1983, p e r s . comm.). The r e s e r v o i r l a k e s a r e v e r y remote and l a c k of i n f o r m a t i o n on t h e i r c h a r a c t e r i s t i c s makes them undependable f o r cage c u l t u r e . The most o b v i o u s and l e a s t e x p e n s i v e source of water i s Moore Creek which i s f e d from the dammed l a k e s , r u n o f f and ground w a t e r . U s i n g the c r e e k water would c o s t the l e a s t f o r development and o p e r a t i o n , p r o v i d e s u i t a b l e temperature water f o r the t r o u t , and i f p r o p e r l y managed, may not pose a h e a l t h problem. Table 8. Water Source E v a l u a t i o n Measures Spr i n g Lake W e l l Creek Equipment/machine(4) (2) 8 (2) 8 (1 ) 4 (3) 1 2 Manpower C o n f l i c t ( 4 ) (1) 4 (2) 4 (1 ) 4 (3) 1 2 F i s h P r o d u c t i o n (5) (2) 1 0 (2) 1 0 (2) 10 (3) 1 5 A c c e p t a b i l i t y (4) (3) 1 2 (2) 8 - (3) 1 2 (2) 8 R e l i a b i l i t y (5) (0) 0 (2) 1 0 (1 ) 5 (2) 1 0 F l e x i b i l i t y (4) ( 1 ) 4 (3) 1 2 (1 ) 4 (2) 8 C a p i t a l Cost (5) (0) 0 (2) 10 (1 ) 5 (3) 1 5 O p e r a t i o n s Cost (5) (3) 1 5 (3) 1 5 (1 ) 5 (3) 15 TOTALS 53 77 49 95 198 c. Water Conveyance. The major water conveyance from the l a k e s o u r c e t o the s i t e w i l l be by Moore Creek, s i n c e a l l o t h e r methods are u n n e c e s s a r i l y e x p e n s i v e . Some c o n t r o l over the water temperature may be e x e r t e d a t the l a k e o u t l e t by t a k i n g advantage of summer t h e r m o c l i n e development by s e t t i n g the depth of water t o be tapped f o r dam o v e r f l o w and en r o u t e by managing the s e a s o n a l cover over the c r e e k . Upstream from the s i t e , a p o r t i o n of the c r e e k must be d i v e r t e d t o the a r t i f i c i a l l y c o n s t r u c t e d c u l t u r e u n i t s , s i n c e i t i s p r e s e n t l y i l l e g a l t o c u l t u r e f i s h i n n a t u r a l water ways. Such a d i v e r s i o n i s most c h e a p l y a c c o m p l i s h e d w i t h a c a n a l such as the i r r i g a t i o n c a n a l s a l r e a d y i n use. However, o n l y p i p e s can both r a i s e water t o any head r e q u i r e d and g i v e f i n e c o n t r o l of f l o w t h r o u g h v a l v i n g . P i p e s can a l s o be d i s m a n t l e d and s t o r e d i n the o f f season. Conveyance between c o n t a i n e r s w i l l depend upon the d e t a i l e d d e s i g n s , but i n g e n e r a l c l o s e d c o n d u i t s may be more e x p e n s i v e than open c h a n n e l s but they can draw from the bottom of ponds ( b e t t e r f o r s o l i d waste removal) and are more r e s i s t a n t to c l o g g i n g from wind blown d i r t and a l g a l f o u l i n g . I t i s recommended t h a t an i n t a k e s t r u c t u r e be b u i l t i n Moore Creek, from which p i p e s l e a d t o and between the f i s h e n c l o s u r e s . 199 T a b l e 9. Water Conveyance E v a l u a t i o n Measures Creek P i p e s Flume Canal Ponds Equipment/machine(4) (3) 1 2 (1 ) 4 (1 ) 4 (2) 8 (1 ) 4 Manpower C o n f l i c t ( 4 ) (3) 1 2 (1 ) 4 (1 ) 4 (2) 8 (1 ) 4 F i s h P r o d u c t i o n (5) (2) 1 0 (3) 1 5 (2) 1 0 (2) 1 0 (1 ) 5 A c c e p t a b i l i t y (4) (2) 8 (3) 1 2 (2) 8 (2) 8 (2) 8 R e l i a b i l i t y (5) (3) 1 5 (2) 10 (3) 1 5 (2) 10 (2) 1 0 F l e x i b i l i t y (4) (3) 1 2 (2) 8 (1 ) 4 (2) 8 (1 ) 4 C a p i t a l Cost (5) (3) 1 5 (1 ) 5 (1 ) 5 (2) 1 0 (1 ) ' 5 O p e r a t i o n s C o s t s (5) (3) 1 5 (2) 1 0 (2) 1 0 (1 ) 5 (1 ) 5 TOTALS 99 73 55 65 45 200 d. Volume.Water Use. T h i s i s r e l a t e d t o the d e s i r e d s i z e of the f a c i l i t y ; the more water, the more f i s h can be r a i s e d . The c o n s t r a i n t s t o t h i s f a c t o r come from the e n v i r o n m e n t a l c o n d i t i o n s ; t h a t i s : how much water can f e a s i b l y be s u p p l i e d a t the peak" of the f i s h r e q uirement season i n August and September, when water l e v e l s a r e lowest i n the r e s e r v o i r s ? From the d i s c h a r g e p r o f i l e of Moore Creek, as d i s c u s s e d under ' S i t e C h a r a c t e r i s t i c s , ' i t i s recommended t h a t a t o t a l of between 2,000 and 8,000 l i t e r s per minute be used f o r the f i s h c u l t u r e , i n c o n j u c t i o n w i t h i r r i g a t i o n r e q u i r e m e n t s , such t h a t the t a i l waters a r e used, when needed, f o r i r r i g a t i o n . e. Water Reuse A l a r g e o p e r a t i o n can e i t h e r t a k e i n a l a r g e amount of s i n g l e pass w ater, or i t can t a k e i n a s m a l l amount of water which i s r e c y c l e d t o a h i g h degree. In keeping w i t h the theme of s i m p l i c i t y and low c o s t i n the i n i t i a l system d e s i g n , m i n i m a l t o p a r t i a l water'use w i t h no pumped r e c y c l i n g i s most d e s i r a b l e . The water may be r e c y c l e d s e r i a l l y , however, t h r o u g h s e v e r a l e n c l o s u r e s , as l o n g as p o l l u t i o n i s a b a t e d between e n c l o s u r e s . P a r t i c u l a r l y on the s i t e i n q u e s t i o n which has a t o t a l of over twenty m i l e s of v a l l e y bottom a t an average s l o p e of 2% which c o u l d be used f o r l a y i n g out e n c l o s u r e s , s e r i a l r e c y c l i n g would be more a p p r o p r i a t e than pumped r e c y c l i n g . S i z i n g of the b i o l o g i c a l f i l t e r s r e q u i r e d f o l l o w s the Table 10. P e r c e n t Water Use E v a l u a t i o n Measures T o t a l P a r t ' 1 Minim I r r i g a t i o n I n t e r r u p t i o n ( 4 ) (1 ) 4 (2) 8 (3) 1 2 Water Wastage (3) (1 ) 3 (2) 6 (3) 9 Equipment/machinery (4) (1 ) 4 (2) 8 (3) 2 Manpower C o n f l i c t (4) (2) 8 (2) 8 (2) 8 F e r t i l i z a t i o n C o n f l i c t (1) (1 ) 1 (2) 2 (3) 3 F i s h P r o d u c t i o n (5) (3) 1 5 (2) 1 0 (1) 5 R e l i a b i l i t y (5) (1 ) 5 (2) 1 0 (3) 1 5 F l e x i b i l i t y (4) (1 ) 4 (2) 8 (3) 1 2 C a p i t a l Cost (5) (1 ) 5 (2) 1 0 (3) 1 5 O p e r a t i o n s C o s t s (5) (1 ) 5 (2) 1 0 (3) 1 5 Revenue (5) (3) 1 5 (2) 10 (1 ) 5 TOTALS 80 88 86 2 0 2 TABLE 11. BIOLOGICAL FILTER DESIGN FOR THE GUICHON PROJECT. ITEM APRIL MAY JUNE JULY AUGUST SEPTEMBR OCTOBER NOVEMBER IMPERIAL DESIGN TEMPERATURE CF) 40.6 45.5 51.8 58.1 60.8 56.7 47.8 39.9 FISH SIZE(INCHES) 7.8 8.1 8.6 9.3 10.1 11 11.6 12 FISH NUMBER 10 9.7 9.4 9.1 8.8 8.5 8.3 8 BIQHASS (POUNDS) 1870 2049 2378 2923 3601 4507 5149 5280 AMMONIA PRODUCTION(LB/100 LB FISH) .024 .025 .027 .031 .031 .028 .023 .02 NITR06ENATI0N RATE(SQ.FT/100LB FISH) 600 250 260 190 190 230 300 510 REQUIRED VOLUME—1 INCH GRAVEL -LOAD RATE (CU.FT./100 LB FISH) 13.5 7.8 5.7 4.5 4.5 5 6.8 12.5 -VOLUME REQUIRED(CU.FT) 252 160 136 132 162 225 350 660 REQUIRED VOLUME—3 INCH GRAVEL -LOAD RATE (CU.FT./100 LB FISH) 38.5 22.1 17.5 13.5 13.5 13 19.2 32.5 -VOLUME REQUIRED(CU.FT) 720 453 416 395 486 586 989 1716 METRIC DESIGN TEMPERATURE C O 4.8 7.5 11 14.5 16 13.7 8.8 4.4 FISH SIZE(GRAMS) 85 96 115 146 186 241 282 300 FISH NUMBER(THOUSAND) 10 9.7 9.4 9.1 8.8 8.5 8.3 8 BIOMASS (KILOGRAMS) 850 931.2 1081 1328.6 1636.8 2048.5 2340.6 2400 AMMONIA PRODUCTION(G/KG) 0.24 0.25 0.27 0.31 0.31 0.28 0.23 0.20 NITROGENATION RATE(S5.N/K6) 1.23 .72 .53 .39 .39 .47 .61 1.04 REQUIRED VOLUME--1 INCH GRAVEL -LOAD RATE (L/KG FISH) 8.4 4.9 3.6 2.8 2.8 3.1 4.2 7.8 -VOLUME REQUIRED(CU.M.) 7.14 4.56 3.89 3.72 4.38 6.35 9.83 18.72 REQUIRED VOLUME-3 INCH GRAVEL -LOAD RATE (L/KG FISH) 24.1 13.7 10.9 8.4 8.4 8.1 11.8 20.2 -VOLUME REBUlREDICU.fi.) 20.49 12.76 11.78 11.16 13.75 16.59 27.62 48.48 T a b l e 12. Water Reuse E v a l u a t i o n Measures S i n g l e Pumped Ser i a l Pass R e c y c l R e c y c l I r r i g a t i o n I n t e r r u p t i o n (4) (2) 8 (3) 1 2 (3) 1 2 Water Wastage (3) (2) 6 (3) 9 (3) 9 Equipment/machinery (4) (3) 1 2 (1 ) 4 (2) 8 Manpower C o n f l i c t (4) (3) 1 2 ( 1 ) 4 (2) 8 F e r t i l i z e r C o n t r i b u t i o n ( 1 ) (1 ) 1 (3) 3 (3) 3 F i s h P r o d u c t i o n (5) (1 ) 5 (3) 1 5 (3) 15 A c c e p t a b i l i t y (4) (3) 1 2 (2) 8 (2) 8 R e l i a b i l i t y (5) (3) 1 5 (1 ) 5 (2) 10 F l e x i b i l i t y (4) (2) 8 (1 ) 4 (3) 12 C a p i t a l Cost (5) (3) 1 5 (1 ) 5 (2) 10 O p e r a t i o n s C o s t s (5) (2) 1 0 (1 ) 5 (2) 10 Revenue (5) (1 ) 5 (3) 1 5 (3) 1 5 TOTALS 1 09 89 1 20 204 method o u t l i n e d i n Speece (1973). An example of the c a l c u l a t i o n s i s shown i n Table 9 i n i m p e r i a l u n i t s ( f o r comparison t o the graphs i n Speece's paper) and c o n v e r t e d t o m e t r i c . I t i s i n t e r e s t i n g t o note t h a t a c c o r d i n g t o the r e l a t i o n s h i p s d e v e l o p e d by Speece, even though f i s h m e t a bolism (t h u s f l o w r e q u i r e m e n t s ) i s h i g h e s t i n warm water, t h i s i s outweighed by the a b i l i t y of the m i c r o o r g a n i s m s i n the b i o l o g i c a l f i l t e r t o m e t a b o l i z e wastes b e t t e r i n warm water. Thus the g r e a t e s t requirement f o r f i l t e r volume o c c u r s a t the c o l d e s t t e m p e r a t u r e . One p o o l s i z e (65 c u b i c meters) f i l t e r c o u l d e a s i l y handle the p o l l u t i o n from t h r e e p o o l s of f i s h , u s i n g 1 i n c h d i a m e t e r g r a v e l (or 3 i n c h Koch r i n g s , w i t h an e q u i v a l e n t a r e a t o volume r a t i o ) as a medium. . I t i s recommended t h a t a s m a l l amount of the a v a i l a b l e water be used many t i m e s , w i t h r e c o n d i t i o n i n g a f t e r p a s s i n g t h r o u g h t h r e e p o o l s , i n a s e r i a l r e c y c l i n g system. f. Water Treatment. The best way t o ensure t h a t good q u a l i t y water i s p r o v i d e d t o the f i s h farm i s th r o u g h a p p r o p r i a t e stream management. Rath e r than h a v i n g t o b u i l d and m a i n t a i n f i l t e r s , the f i s h c u l t u r i s t s s h o u l d make sure t h a t the stream has a good green b e l t around i t t o keep s i l t a t i o n a t a minimum. An o v e r s t o r y of de c i d u o u s t r e e s w i l l l e t sun i n d u r i n g the s p r i n g t o h e l p warm the water, y e t keep sun out d u r i n g the summer when water t e m p e r a t u r e s can get t o o hot f o r good f i s h h e a l t h . T a b l e 13 o u t l i n e s the d e s i g n and c o s t of b u i l d i n g a " s o l a r 2 0 5 T A B L E 1 3 . S O L A R H E A T I N G D E S I G N T A B L E FOR THE GUICHON P R O J E C T . I T E M A P R I L MAY J U N E J U L Y AU6UST SEPTEMBR OCTOBER NOVEMBER 1 . TEMPERATURE R E Q U I R E D - A M B I E N T HATER C O 4 . 8 7 . 5 11 1 4 . 5 16 1 3 . 7 8 . 8 4 . 4 - A M B I E N T A I R (MAXIMUM H E A T A B L E . ' C ) 4 . 6 9 . 2 1 3 . 3 1 6 . 5 1 7 . 5 1 5 . 1 1 0 . 4 4 . 1 - T E M P E R A T U R E D I F F E R E N C E C C ) 1 . 7 2 . 3 . 5 1 . 3 1 . 6 2 . FLOW R E Q U I R E D - F I S H S I Z E ( G R A M S ) 7 5 8 6 1 1 0 141 181 2 3 7 2 7 9 3 0 0 - N O . OF F I S H 1 0 0 0 0 9 7 0 0 9 4 0 0 9 1 0 0 8 8 0 0 8 5 0 0 8 3 0 0 8 0 0 0 - B I O M A S S ( K I L O G R A M S ) 7 5 0 8 3 4 . 2 1 0 3 4 1 2 8 3 . 1 1 5 9 2 . 8 2 0 1 4 . 5 2 3 1 5 . 7 2 4 0 0 - L O A D R A T E ( K 6 / L P H ) 2 . 3 6 1 . 4 3 . 8 8 . 7 5 . 7 8 . 8 1 6 1 . 4 8 4 . 0 0 - F L O N ( L P H ) 3 1 7 . 8 0 5 8 3 . 3 6 1 1 7 5 . 0 0 1 7 1 0 . 8 0 2 0 4 2 . 0 5 2 4 6 8 . 7 5 1 5 6 4 . 6 6 6 0 0 . 0 0 3 . COLLECTOR C H A R A C T E R I S T I C S - S L O P E ( D E G R E E S ) 0 0 0 0 0 0 0 0 - A S P E C T ( D E G R E E S ) 0 0 0 0 0 0 0 0 - E F F I C I E N C Y ( X ) 10 10 10 10 10 10 10 10 4 . E N E R 6 Y A V A I L A B L E - I N C I D E N T R A D I A T I O N ( M J / S Q . M - D A Y ) 1 4 . 1 1 8 . 7 4 2 1 . 7 3 2 3 . 1 6 2 1 . 6 2 1 7 . 0 1 1 1 . 4 6 6 . 1 4 - E X P O S U R E T I M E ( D A Y S ) 1 1 1 1 1 1 1 1 - U S A B L E E N E R G Y ( M J / S Q . M - D A Y ) 1 . 4 1 1 . 8 7 2 . 1 7 2 . 3 2 2 . 1 6 1 . 7 0 1 . 1 5 0 . 6 1 S . SOLAR D E S I G N - M A S S H E A T E D ( T D N N E S / D A Y ) 8 4 0 . 0 3 1 6 9 2 . 0 0 2 4 6 3 . 5 5 2 9 4 0 . 5 5 3 5 5 5 . 0 0 2 2 5 3 . 1 1 - T H E R M A L C A P A C I T Y OF H A T E R ( J / K 6 ) 4 1 8 4 4 1 8 4 4 1 8 4 4 1 8 4 4 1 8 4 - E N E R 6 Y REQUIRED PER D A Y ( M J ) 5 9 7 4 . 9 9 1 6 2 8 2 . 4 5 5 1 5 3 . 7 5 1 9 3 3 6 . 3 6 1 5 0 8 3 . 2 4 - A R E A R E Q U I R E D ( S 8 . M E T E R S ) 3 1 8 8 . 3 6 7 4 9 3 . 0 8 2 2 2 5 . 2 8 1 1 3 6 7 . 6 4 1 3 1 6 1 . 6 4 6 . COLLECTOR C O N S T R U C T I O N . - W I D T H (METERS) 10 10 10 10 10 - L E N G T H (METERS) 3 1 8 . 8 4 7 4 9 . 3 1 2 2 2 . 5 3 1 1 3 6 . 7 6 1 3 1 6 . 1 6 - D E P T H (METERS) 1 1 1 1 1 - E X C A V A T I O N COST < « 1 0 / C U N) 3 1 8 8 4 7 4 9 3 1 2 2 2 5 3 1 1 3 6 7 6 1 3 1 6 1 6 - P L A S T I C L I N E R l $ 3 . 2 6 / H ) 1 0 3 9 2 4 4 3 7 2 5 3 7 0 6 4 2 9 1 - T O T A L COST 3 2 9 2 3 7 7 3 7 4 2 2 9 7 8 1 1 7 3 8 2 1 3 5 9 0 7 * • V A L U E S ARE FOR F I R S T DAY OF EACH MONTH. 206 pond", p a s s i v e type s o l a r c o l l e c t o r t o heat the p r o c e s s water. The assumptions and c r i t e r i a f o r t h i s t a b l e a r e as f o l l o w s : 1. Temperature: the main c o n s t r a i n t t o the cheap s o l a r pond type of c o l l e c t o r i s t h a t i t cannot e f f e c t i v e l y r a i s e water temperature above ambient t e m p e r a t u r e . To get h i g h e r t e m p e r a t u r e s , a c t i v e c o l l e c t o r s must be used, none of which p r e s e n t l y can heat l a r g e volumes of water w i t h o u t a s t r o n o m i c a l c a p i t a l c o s t . Temperatures f o r a i r and water g i v e n i n the t a b l e a r e i n t e r p o l a t e d means f o r the f i r s t day of each month, (not monthly averages) d e r i v e d from the M e r r i t t v a l u e s i n the Canadian C l i m a t e Normals 1951-1980 (Canadian C l i m a t e Program, 1982) and the Upper N i c o l a v a l u e s i n Water t e m p e r a t u r e s : B. C. and Yukon ( I n l a n d Waters D i r e c t o r a t e , 1977). The temperature d i f f e r e n c e i s shown f o r those months where a c o l l e c t o r c o u l d be u s e f u l , t h a t i s when the a i r i s warmer than the water. A maximum temperature of 15°C was used f o r c o l l e c t o r h e a t i n g . 2. Flow R e q u i r e d : a t the s l i g h t l y warmer te m p e r a t u r e s p r o v i d e d by s o l a r heated w a t e r , s m a l l e r f i s h can be s t o c k e d and s t i l l r e ach the 300 gram h a r v e s t s i z e by November 1. The growth and l o a d r a t e programs (see the Model Design s e c t i o n ) p r e d i c t e d the s i z e s of f i s h and f l o w l o a d i n g a t v a r i o u s t i m e s i n the t a b l e . The f l o w i s the minimum e s t i m a t e d r e q u i r e d f o r one p o o l (or l i n e of p o o l s ) . 3. C o l l e c t o r C h a r a c t e r i s t i c s : f o l l o w i n g the d e s i g n method g i v e n by Hay (1979), s l o p e i s i n degrees from h o r i z o n t a l 207 (a pond cannot be i n c l i n e d ) , a s p e c t ( d i r e c t i o n the c o l l e c t o r f a c e s ) i s i n the a r c h a i c a s t r o n o m i c a l nomenclature ( s o u t h i s 0°) used by Hay r a t h e r than s t a n d a r d n a v i g a t i o n a l ( n o r t h i s 0° ) nomenclature. E f f i c i e n c y i s an o p t i m i s t i c e s t i m a t i o n f o r a b l a c k p l a s t i c c o v e r e d d i t c h c o l l e c t o r . 4. Energy A v a i l a b l e : u s e a b l e energy i s the amount of megajoules per square meter a v a i l a b l e f o r heat a t the e f f i c i e n c y g i v e n over one day's ti m e . 5. S o l a r D e s i g n : mass heated i s the t o t a l f l o w i n a day, energy r e q u i r e d i s the mass tim e s the change i n temperature t i m e s the t h e r m a l c a p a c i t y of water, and a r e a r e q u i r e d i s energy r e q u i r e d d i v i d e d by u s e a b l e energy. 6. C o l l e c t o r C o n s t r u c t i o n : t h i s assumes t h a t a 10 meter wide by 1 meter deep d i t c h , l i n e d w i t h b l a c k p l a s t i c i s the cheapest c o l l e c t o r p o s s i b l e . E x c a v a t i o n c o s t s of $10 per c u b i c meter a r e $5 below the l o w e s t e s t i m a t e s u b m i t t e d t o the Department of F i s h e r i e s and Oceans i n 1982(A. Rowland, p e r s . comm.). T h i s assumes much a s s i s t a n c e from ranch machinery. S i x m i l l i m e t e r b l a c k p l a s t i c comes i n 40 f t . by 100 f t . r o l l s a t $99.16 each ($3.26 per meter of c o l l e c t o r ) . The o n l y c o s t s a v i n g i n e n g i n e e r i n g warmer water i s so t h a t s m a l l e r , cheaper f i n g e r l i n g s can be s t o c k e d . The d i f f e r e n c e i n c o s t f o r d i f f e r e n t s i z e s of f i s h i s about 1% per gram. Bei n g a b l e t o s t o c k 75 gram i n s t e a d of 85 gram f i s h c o u l d mean a s a v i n g s of about 10% on f i s h c o s t . T h e r e f o r e , t o be a 208 w o r t h w h i l e i n v e s t m e n t , the s o l a r pond s h o u l d c o s t l e s s than 10% of the c o s t of the f i s h . The h i g h e s t s o l a r i n p u t requirement i s i n October (1316 meters of pond), c o s t i n g $135,906. The c o s t of f i s h f o r one p o o l i s $4000 (10,000 f i s h at $400 per thousand 85 gram f i s h ) . Ten p e r c e n t of t h i s i s $400. The s o l a r pond would have t o heat 340 ponds i n a row t o r e c o v e r i t s c o s t i n one y e a r . Even i f the pond had an o p e r a t i n g l i f e of 10 y e a r s , 34 ponds i n a row would be needed. The lowest h e a t i n g requirement i s i n J u l y , but t o r a i s e the temperature a mere 0.5°C and r e c o v e r c o s t s i n 10 y e a r s would r e q u i r e more than 6 ponds i n a row. That 0.5°C temperature d i f f e r e n c e i n J u l y would, however, make an almost i n s i g n i f i c a n t d i f f e r e n c e i n growth over the e n t i r e season. T h e r e f o r e s o l a r h e a t i n g of t h i s k i n d i s not a v i a b l e o p t i o n . In the same v e i n , h e a t i n g water throughout the growing season t o the optimum growth temperature of 15°C by c o n v e n t i o n a l means would a l l o w s t o c k i n g of even s m a l l e r , cheaper f i s h . The growth e q u a t i o n e s t i m a t e s t h a t 50 gram f i s h c o u l d be s t o c k e d and s t i l l r e a c h market s i z e by November 1. T a b l e 14 g i v e s the d e t a i l s of t h i s o p t i o n . Requirements a r e based on the same r e l a t i o n s h i p s as f o r s o l a r h eat. H e a t i n g c o s t s f o r the two t y p e s of h e a t e r a r e based s o l e l y on the c o s t of o i l and e l e c t r i c i t y - no c a p i t a l c o s t s a r e c o n s i d e r e d . I f a 35% s a v i n g s i n p r o d u c t i o n c o s t s were t o be g a i n e d from s t o c k i n g 50 gram f i s h r a t h e r than 80 gram f i s h , then the c o s t of h e a t i n g s h o u l d be l e s s than 35% of t h a t c o s t , t o make the e x t r a t r o u b l e w o r t h w h i l e . From another a n g l e , t o r e c o v e r the $75,000 r e q u i r e d T A B L E 1 4 . CONVENTIONAL HEATER D E S I 6 N AND COSTING FOR THE GUICHON P R O J E C T . I T E H A P R I L MAY JUNE J U L Y AUGUST S E P T E H B R OCTOBER . TEMPERATURE REQUIRED - A H B I E N T WATER C O 4 . B 7 . 5 11 1 4 . 5 16 1 3 . 7 8 . 8 - O P T I HUH GROWTH TEMPERATURE C O I S 15 15 15 15 15 15 - T E M P E R A T U R E D I F F E R E N C E C O 1 0 . 2 7 . 5 4 . 5 1 . 3 6 . 2 ! . FLOW REQUIRED - F I S H S I Z E ( G R A M S ) 5 0 7 0 9 6 1 2 6 1 6 2 2 0 5 2 5 4 - N O . OF F I S H 10 9 . 7 9 . 4 9 . 1 8 . 8 8 . 5 8 . 3 - B I O M A S S ( K I L O G R A M S ) 5 0 0 6 7 9 9 0 2 . 4 1 1 4 6 . 6 1 4 2 5 . 6 1 7 4 2 . 5 2 1 0 8 . 2 - L O A D R A T E I K 6 / L P H ) . 6 2 S . 6 6 5 . 7 . 7 3 3 . 7 6 5 . 7 9 6 . 8 2 6 - F L O W ( L P H ) 7 9 6 1021 1 2 8 9 1 5 6 4 1 8 6 4 2 1 8 9 2 5 5 2 3 . HEATER D E S I 6 N - M A S S HEATED(TONNES/DAY) 1 1 4 6 1 4 7 0 1 8 5 6 2 2 5 3 2 6 8 3 3 1 5 2 3 6 7 5 -THERMAL C A P A C I T Y OF H A T E R ( J / K G ) 4 1 8 4 4 1 8 4 4 1 8 4 4 1 8 4 4 1 8 4 4 1 8 4 4 1 8 4 - E N E R G Y REQUIRED PER D A Y ( M J ) 4 8 9 2 9 4 6 1 3 9 3 1 0 6 8 4 7 1 2 1 7 1 4 6 9 5 3 4 1 4 . O I L F I R E D HEATER - O I L ( 8 2 9 M J / L ) 1 6 8 7 . 2 0 1 5 9 0 . 9 8 1 0 7 1 . 3 2 5 9 1 . 2 3 3 2 8 7 . 6 0 - C 0 S T / D A Y ( $ . 3 0 / L O I L ) 5 0 6 . 1 6 4 7 7 . 2 9 3 2 1 . 3 9 1 7 7 . 3 7 9 8 6 . 2 8 -COST/MONTH 1 5 1 8 4 . 8 0 1 4 7 9 6 . 1 4 9 6 4 1 . 8 4 5 3 2 1 . 1 0 3 0 5 7 4 . 7 3 7 5 5 1 9 5 . D E I S E L E L E C T R I C HEATER - F U E L C O S T / D A Y ( $ . 0 7 / L P M - ' C ) 5 6 8 . 4 7 5 3 6 . 0 5 3 6 0 . 9 6 -COST/MONTH 1 7 0 5 4 . 1 4 1 6 6 1 7 . 6 3 1 0 8 2 8 . 8 0 1 9 9 . 2 1 1 1 0 7 . 7 0 5 9 7 6 . 1 6 3 4 3 3 8 . 6 5 8 4 8 1 5 210 f o r o i l would r e q u i r e t h a t $214,000 worth of f i s h be bought each y e a r , enough f o r more than 53 ponds (on one water s u p p l y ) . T h i s i s t h e r e f o r e not a v i a b l e o p t i o n . The c o n f l i c t i n d e c i d i n g whether t o a e r a t e or not i s r e l a t e d t o the s c a l e of the o p e r a t i o n . A e r a t i o n i s r e q u i r e d i f p o o l s are a r r a n g e d i n l i n e s w i t h the e f f l u e n t from one becoming the i n f l u e n t of the n e x t . I f each p o o l feeds o f f the c r e e k , however, the n a t u r a l a e r a t i o n of the c r e e k s h o u l d s u f f i c e . For s e v e r a l p o o l s , i t i s cheaper t o have water f l o w from one t o the next than t o have s e p a r a t e i n t a k e s t r u c t u r e s . The problem i s one of h y d r a u l i c head. A e r a t o r d e s i g n c a l c u l a t i o n s a r e g i v e n i n T a b l e 15, based on the McLean and Boreham (1980) model. A minimum of 5 segments f o r a packed column (2 meters) a r e r e q u i r e d t o r e - a e r a t e the water between p o o l s . For a g r a v i t y s u p p l y system, at a s l o p e of 20 per thousand, t h i s r e q u i r e s 100 meters of p i p e l i n e between p o o l s . At l e a s t the same l e n g t h of p i p e l i n e , p l u s the i n t a k e s t r u c t u r e , v a l u e and c o u p l i n g s would be r e q u i r e d f o r i n d i v i d u a l i n t a k e s . The o v e r a l l c o s t s would p r o b a b l y come out q u i t e s i m i l a r i f a number of s u i t a b l e i n t a k e s i t e s c o u l d be found. However, a r e a s of s t e e p e r s l o p e on the Guichon Ranch c o u l d be found f o r the f i s h farm l o c a t i o n , r e q u i r i n g l e s s space between p o o l s . 2.11 T A B L E 1 5 . A E R A T I O N REQUIREMENTS FOR THE GUICHON P R O J E C T . I T E M A P R I L HAY J U N E J U L Y AUGUST S E P T E H B R OCTOBER NOVEMBER TEMPERATURE C O OXYGEN S A T U R A T I O N ( H 6 / L ) D A V I S ' B ' L E V E L ( M 6 / L 0 2 ) OUTFLOW 0 X Y 6 E N (X S A T U R A T I O N ) A E R A T I O N CONSTANT 4 . 8 1 2 . 9 0 7 . 3 5 5 7 . 3 9 7 . 5 11 1 4 . 5 16 1 3 . 7 8 . 8 4 . 4 9 . 8 9 1 0 . 3 8 1 1 . 6 3 1 3 . 0 3 5 . 9 1 6 . 0 4 6 . 6 1 7 . 4 4 5 9 . 8 5 8 . 2 5 6 . 8 5 7 . 1 . 4 7 . 4 5 . 4 2 . 3 9 1 2 . 1 1 1 . 0 4 1 0 . 2 1 6 . 8 2 6 . 3 1 5 . 9 9 5 6 . 8 5 7 . 2 5 8 . 7 . 4 1 . 4 3 . 4 6 AERATOR PERFORMANCE -I S A T U R A T I O N A F T E R COLUMN 1 7 0 . 7 9 7 1 . 3 2 7 2 . 1 5 7 3 . 9 2 7 4 . 8 7 7 3 . 3 4 7 1 . 6 1 7 0 . 9 5 8 0 . 1 6 8 0 . 9 6 8 1 . 8 8 8 3 . 5 3 8 4 . 2 9 8 3 . 0 0 8 1 . 3 4 8 0 . 3 2 8 6 . 5 3 8 7 . 3 6 3 . 2 1 8 9 . 6 1 9 0 . 1 8 9 . 1 5 8 7 . 7 4 8 6 . 6 7 9 0 . 8 5 9 1 . 6 1 9 2 . 3 3 9 3 . 4 3 9 3 . 8 6 9 3 . 0 8 9 1 . 9 4 9 0 . 9 8 9 3 . 7 9 9 4 . 4 3 9 5 . 0 1 9 5 . 8 5 9 6 . 1 6 9 5 . 5 9 9 4 . 7 1 9 3 . 8 9 9 5 . 7 8 9 6 . 3 2 9 6 . 7 5 9 7 . 3 8 9 7 . 6 1 9 7 . 1 9 9 6 . 5 2 9 5 . 8 6 212 T a b l e 16. Water Treatment E v a l u a t i o n Measures F i l t e r -not Heat -not A e r a t e -not E q u i p Mach(4) (2) 8 (3) 1 2 (2) 8 (3) 1 2 (2) 8 (3) 12 Manpwr Con(4) (2) 8 (3) 1 2 (2) 8 (3) 1 2 (2) 8 (3) 1 2 F i s h Prod (5) (3) 1 5 (1 ) 5 (3) 1 5 (2) 1 0 (3) 1 5 (2) 10 A c c e p t a b i 1 ( 4 ) (3) 1 2 (2) 8 (3) 1 2 (2) 8 (3) 12 (2) 8 R e l i a b i l i t ( 5 ) (3) 1 5 (2) 10 (3) 1 5 (2) 10 (3) 1 5 (2) 10 F l e x i b i l i t ( 4 ) (3) 1 2 (2) 8 (2) 8 (3) 1 2 (3) 1 2 (2) 8 C a p i t C o s t ( 5 ) (1 ) 5 (2) 1 0 (1 ) 5 (3) 1 5 (2) 1 0 (3) 1 5 Oper C o s t s ( 5 ) (1 ) 5 (2) 1 0 (1 ) 5 (3) 1 5 (2) 10 (3) 1 5 TOTALS 80 75 76 . 94 90 90 213 g. F i s h Type. The k i n d s of f i s h which might be c u l t u r e d have been d i s c u s s e d e a r l i e r , w i t h the c o n c l u s i o n t h a t t r o u t are the most s u i t a b l e from the s t a n d p o i n t of growth r a t e , market a c c e p t a b l i 1 i t y , d o l l a r v a l u e and proven c u l t u r e c a p a b i l i t y . I t i s recommended t h a t Rainbow T r o u t (Salmo g a i r d n e r i , R i c h a r d s o n ) be c u l t u r e d . Research may be done on s m a l l c y p r i n i d s f o r use as l i v e s t o c k f e e d supplements. h. F i s h E n c l o s u r e . The s i t e of t h i s a n a l y s i s c a l l s f o r raceway or pond c u l t u r e of some t y p e , s i n c e n a t u r a l l a k e and stream c u l t u r e a r e i l l e g a l and cage c u l t u r e i n the r e s e r v o i r s would be i m p r a c t i c a l because of t h e i r remoteness, c o l d t e m p e r a t u r e s and drawdown, which empties some of the r e s e r v o i r s i n the summer. To use up as l i t t l e of the v a l l e y bottom g r a z i n g l a n d as p o s s i b l e , an i n t e n s i v e raceway c u l t u r e would be more s u i t a b l e . The above ground "swimming p o o l " i s the l e a s t e x p e n s i v e and most a d a p t a b l e o p t i o n f o r a raceway c o n t a i n e r . I t i s recommended t h a t p l a s t i c l i n e d raceways be used. i . F i s h Food Dependence upon n a t u r a l p r o d u c t i o n of f i s h food ( a q u a t i c i n s e c t l a r v a e , e t c ) from the stream would not a l l o w f o r r e a r i n g v e r y many f i s h . The d i r e c t use of a n i m a l waste f o r f o o d , as has been t r i e d f o r c a r p , has not s u c c e s s f u l l y been a p p l i e d t o t r o u t 214 T a b l e 17. F i s h Type E v a l u a t i o n Measures Trout Carp Reduc- Exot i c P o l y -t i o n F i s h C u l t r Manpower C o n f l i c t ( 4 ) (2) 8 (3) 1 2 (3) 1 2 (3) 1 2 (3) 12 Waste U t i l i z a t i o n ( 1 ) (1 ) 1 (2) 2 (3) 3 (3) 3 (3) 3 F e r t i z e r C o n t r b t n ( l ) (2) 2 (3) 3 (3) 3 (3) 3 (3) 3 F i s h P r o d u c t i o n (5) (3) 1 5 (1 ) 5 (2) 1 0 (1 ) 5 (1 ) 5 A c c e p t a b i l i t y (4) (3) 1 2 (1 ) 4 (1 ) 4 (0) 0 (1 ) 4 R e l i a b i l i t y (5) (3) 1 5 (2) 10 (1 ) 5 (1 ) 5 (1 ) 5 F l e x i b i l i t y (4) (2) 8 (3) 1 2 (3) 1 2 (2) 8 (2) 8 C a p i t a l Cost (5) (2) 1 0 (3) 1 5 (3) 1 5 (3) 1 5 (3) 15 O p e r a t i o n s Cost (5) (1 ) 5 (3) 1 5 (3) 1 5 (3) 1 5 (3) 15 Revenue (5) (3) 15 (1) 5 (1 ) 5 (1) 5 (1 ) 5 TOTALS 91 83 84 71 75 215 T a b l e 18. F i s h E n c l o s u r e E v a l u a t i o n Measures Lake E a r t h Con- P l a s t - W i l d I r r i g Cage Pond c r e t e t i c Creek Canal Equip/mach(4) (2) 8 (2) 8 ( 1 ) 4 (2) 8 (3) 1 2 (2) 8 Manpwr Con(4) (1 ) 4 (2) 8 (2) 8 (2) 8 (3) 1 2 (3) 12 Wast U t i l (1) (2) 2 (3) 3 (1) 1 ( 1 ) 1 (3) 3 (3) 3 F i s h Prod (5) (2) 1 0 (2) 1 0 (3) 1 5 (3) 1 5 (1 ) 5 ( 1 ) 5 A c c e p t a b i 1 ( 4 ) (3) 1 2 (3) 1 2 (2) 8 (3) 1 2 (3) 1 2 (2) 8 R e l i a b i l i t ( 5 ) (2) 10 (2) 1 0 (3) 1 5 (3) 1 5 (1 ) 5 (1 ) 5 F l e x i b i l i t ( 4 ) (2) 8 (3) 1 2 (2) 8 (3) 1 2 (2) 8 (2) 8 C a p i t C o s t ( 5 ) (2) 1 0 (2) 1 0 (1) 5 (2) 10 (3) 1 5 (2) 10 Oper Cost (5) (2) 10 (3) 1 5 (2) 10 (2) 1 0 (3) 1 5 (2) 10 TOTALS 74 88 74 91 87 69 216 c u l t u r e . T rout are c a r n i v o r e s and would not be e x p e c t e d to fe e d on raw p r o t e i n mush u n l e s s i t were c a r e f u l l y mixed, p e l l e t e d and f l a v o u r e d as are commercial t r o u t f e e d s . Commercial feeds ar e v e r y r e l i a b l e and e f f e c t i v e . However, t h e i r c o s t n o r m a l l y makes up the major o p e r a t i n g c o s t of a f a c i l i t y . On the s u r f a c e , c u l t u r i n g food organisms t o feed t o the t r o u t would seem t o be a l e s s e x p e n s i v e o p t i o n because the m a t e r i a l i n p u t ( f e r t i l i z e r ) i s cheaper than commercial f o o d . T a b l e 19 e v a l u a t e s the t h e o r e t i c a l l e a s t r e q u i r e m e n t s of t h i s o p t i o n based on i d e a l c o n d i t i o n s and on the f o l l o w i n g c r i t e r i a : i ) F i s h Requirements: t o c a l c u l a t e the amount of z o o p l a n k t o n and a l g a e t h a t need t o be grown t o meet the food r e q u i r e m e n t s of the f i s h i n each p o o l , the number of f i s h per pond were m u l t i p l i e d by the weight of each f i s h t o get biomass, which was m u l t i p l i e d by a r e a s o n a b l e fe e d r a t e f o r t h a t s i z e of f i s h t o get the amount of commercial fee d which would be f e d per day. i i ) Z ooplankton Requirements: f i s h food was t r a n s l a t e d t o the amount of Daphnia r e q u i r e d by u s i n g n i t r o g e n as the exchange c u r r e n c y . N i t r o g e n i s about 12%.of the dry weight of both commercial foods and Daphnia, t h e r e f o r e the d r y weight of z o o p l a n k t o n t h a t would be r e q u i r e d i s about the same as the weight of f i s h f o o d . Daphnia can be c u l t u r e d i n t e n s i v e l y up t o about 100 i n d i v i d u a l s per l i t e r , which t r a n s l a t e s t o about 60 m i l l i g r a m s per l i t e r . D i v i d i n g the weight of Daphnia needed by t h i s d e n s i t y gave the volume of c u l t u r e which must be h a r v e s t e d t o p r o v i d e t h a t amount 217 T A B L E 1 9 . S I Z E AND COST OF M U L T I - T R O P H I C CULTURE O P T I O N A P R I L MAY J U N E J U L Y AUGUST SEPTEMBR OCTOBER NOVEMBER F I S H FOOD REQUIREMENTS - T E M P E R A T U R E C O 4 . 8 7 . 5 11 1 4 . 5 16 1 3 . 7 8 . 8 4 . 4 - F I S H S I Z E ( S M S ) 8 5 9 6 1 1 5 1 4 6 1 8 6 2 4 1 2 8 2 3 0 0 - F I S H NUMBER(THOUSANDS) 10 9 . 7 9 . 4 9 . 1 8 . 8 8 . 5 8 . 3 8 - B I O M A S S ( K S ) 8 5 0 9 3 1 1 0 8 1 1 3 2 9 1 6 3 7 2 0 4 9 2 3 4 1 2 4 0 0 - F E E D R A T E ( X / D A Y ) 1 . 1 1 . 2 1 . 6 1 . 8 1 . 9 1 . 7 1 . 2 1 - F E E D R E Q U I R E M E N T S ( K B / D A Y ) 9 . 3 5 1 1 . 1 7 1 7 . 3 0 2 3 . 9 1 3 1 . 1 0 3 4 . 8 2 2 8 . 0 9 2 4 . 0 0 DAPHNIA REQUIREMENTS - F E E D N I T R O G E N ( X ) 6 . 4 6 . 4 6 . 4 6 . 4 6 . 4 6 . 4 6 . 4 6 . 4 - N I T R O G E N R E Q U I R E D ( K G / D A Y ) 0 . 6 0 0 . 7 2 1 . 1 1 1 . 5 3 1 . 9 9 2 . 2 3 1 . 8 0 1 . 5 4 - D A P H N I A N I T R O G E N S ) 12 12 12 12 12 12 12 12 - D A P H N I A R E Q U I R E D ( K G / D A Y ) 4 . 9 9 5 . 9 6 9 . 2 2 1 2 . 7 5 1 6 . 5 9 1 8 . 5 7 1 4 . 9 8 1 2 . 8 0 - D A P H N I A LOAD R A T E ( M G / L ) 6 0 6 0 6 0 6 0 6 0 6 0 6 0 6 0 - V O L U M E H A R V E S T E D ( C U H) 8 3 . 1 1 9 9 . 3 3 1 5 3 . 7 4 2 1 2 . 5 8 2 7 6 . 4 4 3 0 9 . 5 5 2 4 9 . 6 6 2 1 3 . 3 3 - H A R V E S T R A T E I X / D A Y ) 5 5 5 5 5 5 5 5 - C U L T U R E VOLUME(CU M) 1 6 6 2 . 2 2 1 9 8 6 . 5 6 3 0 7 4 . 8 4 4 2 5 1 . 5 2 5 5 2 8 . 7 5 6 1 9 1 . 0 2 4 9 9 3 . 2 8 4 2 6 6 . 6 7 A L G A E REQUIREMENTS - C O N V E R S I O N E F F I C I E N C Y ( Z ) 7 0 7 0 7 0 7 0 7 0 7 0 7 0 7 0 - N I T R O G E N R E Q U I R E D ( K G / D A Y ) 0 . 4 2 0 . 5 0 0 . 7 7 1 . 0 7 1 . 3 9 1 . 5 6 1 . 2 6 1 . 0 8 - A L G A E N I T R Q G E N ( X ) 8 . 5 8 . 5 8 . 5 8 . 5 8 . 5 8 . 5 8 . 5 8 . 5 - A L G A E R E Q U I R E D ( K G / D A Y 4 . 9 3 5 . 8 9 9 . 1 2 1 2 . 6 0 1 6 . 3 9 1 8 . 3 5 1 4 . 8 0 1 2 . 6 5 - A L G A E LOAD R A T E I M G / L ) 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 -VOLUME H A R V E S T E D ( C U M) 9 8 . 5 6 1 1 7 . 7 9 1 8 2 . 3 2 2 5 2 . 0 9 3 2 7 . 8 2 3 6 7 . 0 9 2 9 6 . 0 7 2 5 2 . 9 9 - H A R V E S T R A T E ( X / D A Y ) 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 - C U L T U R E VOLUME(CU M) 1 9 7 . 1 2 2 3 5 . 5 8 3 6 4 . 6 4 5 0 4 . 1 8 6 5 5 . 6 4 7 3 4 . 1 8 5 9 2 . 1 4 5 0 5 . 9 8 CONSTRUCTION COSTS - C U L T U R E WIDTH(M) 10 10 10 10 10 10 10 10 - C U L T U R E DEPTH(M) 1 1 1 1 1 1 1 1 - D A P H N I A L E N G T H ( M ) 1 6 6 . 2 2 1 9 8 . 6 6 3 0 7 . 4 8 4 2 5 . 1 5 5 5 2 . 8 7 6 1 9 . 1 0 4 9 9 . 3 3 4 2 6 . 6 7 - A L G A E L E N G T H ( M ) 1 9 . 7 1 2 3 . 5 6 3 6 . 4 6 5 0 . 4 2 6 5 . 5 6 7 3 . 4 2 5 9 . 2 1 5 0 . 6 0 - T O T A L L E N G T H ( M ) 1 8 5 . 9 3 2 2 2 . 2 1 3 4 3 . 9 5 4 7 5 . 5 7 6 1 8 . 4 4 6 9 2 . 5 2 5 5 8 . 5 4 4 7 7 . 2 6 - E X C A V A T I O N C O S T ( $ / C U M) 10 10 10 10 10 10 10 10 - D A P H N I A E X C A V A T I O N ( $ ) 1 6 6 2 2 . 2 2 1 9 8 6 5 . 6 0 3 0 7 4 8 . 4 4 4 2 5 1 5 . 2 0 5 5 2 8 7 . 4 7 6 1 9 1 0 . 2 2 4 9 9 3 2 . 8 0 4 2 6 6 6 . 6 7 - A L G A E E X C A V A T I O N ( $ ) 1 9 7 1 . 2 0 2 3 5 5 . 8 3 3 6 4 6 . 4 0 5 0 4 1 . 8 0 6 5 5 6 . 4 4 7 3 4 1 . 8 2 5 9 2 1 . 4 4 5 0 5 9 . 7 6 - T O T A L E X C A V A T I O N ( $ ) ' 1 8 5 9 3 . 4 2 2 2 2 2 1 . 4 3 3 4 3 9 4 . 3 5 4 7 5 5 7 . 0 0 6 1 8 4 3 . 9 1 6 9 2 5 2 . 0 5 5 5 8 5 4 . 2 4 4 7 7 2 6 . 4 3 COST COMPARISON COMMERCIAL F E E D C O S T ( $ / Y R ) TIME TO BREAK E V E N ( Y E A R S ) 3 4 4 0 3 4 4 0 3 4 4 0 3 4 4 0 3 4 4 0 3 4 4 0 3 4 4 0 3 4 4 0 5 . 4 1 . 6 . 4 6 1 0 . 0 0 1 3 . 8 2 1 7 . 9 8 2 0 . 1 3 1 6 . 2 4 1 3 . 8 7 T a b l e 20. F i s h Food Type E v a l u a t i o n Measures W i l d Bought C u l t - Di r e c t Food Feed u r e d Wastes Equipment/machine (4) (3) 1 2 ( 1 ) 4 (1 ) 4 (2) 8 Manpower C o n f l i c t (3) (3) 1 2 (2) 8 (1 ) 4 (2) 8 Waste U t i l i z a t i o n (1 ) (1 ) 1 (2) 1 (3) 3 (3) 3 F e r t i l C o n t r i b u t n ( 1 ) (0) 0 (2) 2 (3) 3 (3) 3 F i s h P r o d u c t i o n (5) (0) 0 (3) 1 5 (1 ) 5 (0) 0 A c c e p t a b i l i t y (4) (1 ) 4 (3) 1 2 (2) 8 (0) 0 R e l i a b i l i t y (5) (0) 0 (3) 1 5 (1 ) 5 (0) 0 F l e x i b i l i t y (4) (1 ) 4 (3) 1 2 (2) 8 (3) 12 C a p i t a l Cost (5) (3) 1 5 (1 ) 5 (2) 10 (3) 15 O p e r a t i o n s C o s t s (5) (3) 1 5 (1 ) 5 (2) 1 0 (3) 15 TOTALS 63 79 60 64 219 of f o o d . However, s i n c e Daphnia p o p u l a t i o n s o n l y i n c r e a s e by 10 t o 15% per day, i n a b s o l u t e l y optimum c o n d i t i o n s , o n l y 10% of the c u l t u r e c o u l d be h a r v e s t e d each day. T h i s growth r a t e does not occur under crowded c o n d i t i o n s , so a h a r v e s t r a t e of 5% i s used. The e n t i r e c u l t u r e s i z e (volume) i s the h a r v e s t e d p o r t i o n d i v i d e d by the h a r v e s t r a t e . i i i ) A l g a e Requirements: a g a i n , n i t r o g e n was used as the c u r r e n c y of exchange, and, f o r s i m p l i c i t y ' s sake, a 100% e f f i c i e n t t r a n s f e r from a l g a e t o Daphnia has been assumed, a l t h o u g h t h i s i s an i m p o s s i b l y o p t i m i s t i c e s t i m a t e . In a l g a e , about 8.5% of d r y weight i s n i t r o g e n . A c u l t u r e d e n s i t y of 50 m i l l i g r a m s per l i t e r was used t o get the volume of h a r v e s t r e q u i r e d . Very r a p i d growth s t i l l o c c u r s a t t h i s d e n s i t y . The model s e c t i o n (next c h a p t e r ) s u g g e s t s t h a t under h i g h n u t r i e n t l o a d i n g s a h a r v e s t of 50% c o u l d be p o s s i b l e . D i v i d i n g t h i s r a t e i n t o the h a r v e s t volume r e q u i r e d g i v e s the e n t i r e a l g a l c u l t u r e volume r e q u i r e d . i v ) C o s t s : o n l y one of many c o s t s was e s t i m a t e d w i t h r e g a r d t o c u l t u r i n g ' n a t u r a l ' food f o r the f i s h - - t h e c o s t of e x c a v a t i n g the c u l t u r e c o n t a i n e r s . I t was assumed t h a t the c h e a p e s t k i n d of c o n t a i n e r would be a s h a l l o w (1 m.), wide (10 m.) d i t c h . The c o s t s f o r Daphnia and a l g a e ponds ar e based on an e s t i m a t e of $10 per c u b i c meter of e x c a v a t i o n , as was used f o r the s o l a r pond e s t i m a t e . No l i n i n g was c o s t e d f o r the ponds, nor c o n t r o l s t r u c t u r e s , h a r v e s t machinery, e x t r a manpower needs, y e a r l y 220 maintenance nor f e r t i l i z e r t o p r o v i d e the i n i t i a l i n p u t of n i t r o g e n . E x c a v a t i o n c o s t was compared t o the c o s t of b u y i n g commercial food f o r the f i s h ($3,440 per y e a r ) by c a l c u l a t i n g the number of y e a r s of o p e r a t i o n f o r the two f e e d i n g methods t o break even w i t h one a n o t h e r . T h i s t a b l e c l e a r l y shows t h a t dependence on m u l t i t r o p h i c c u l t u r e i s a c t u a l l y a v e r y e x p e n s i v e , as w e l l as u n r e l i a b l e , o p t i o n . C u l t u r i n g of food organisms may be v a l u a b l e as a d i e t a r y supplement t o improve f i s h h e a l t h , t a s t e and f l e s h q u a l i t y . • I t i s recommended t h a t commercial feeds be used f o r r e a r i n g the t r o u t . j . Energy Source The most a t t r a c t i v e s o u r c e of energy f o r t h e Guichon s i t e i s the g r a v i t y f l o w of the stream, whether used i n the p r i m a r y sense t o p r o p e l the water through the system, or i n the secondary sense t o g e n e r a t e m e c h a n i c a l or e l e c t r i c a l energy. A g r a v i t y f l o w system f a r s u r p a s s e s e l e c t r i c a l or f u e l e d pumps i n economy, s o l a r and wind power i n t e c h n i c a l f e a s i b i l i t y , and a l l of the above i n r e l i a b i l i t y . I t i s recommended t h a t the f a c i l i t y be d e s i g n e d t o take b e s t advantage of the g r a v i t y f l o w energy a v a i l a b l e on the s i t e . 221 T a b l e 21. Energy Source E v a l u a t i o n Measures E l e c t - F u e l Grav - S o l a r Wind r i c a l O i l i t y Power Power Equipmemt/machine (4) ( 1 ) 4 (1 ) 4 (2) 8 (1 ) 4 (1 ) 4 Manpower C o n f l i c t (4) (2) 8 (2) 8 (3) 1 2 (3) 1 2 (3) 12 R e l i a b i l i t y (5) (2) 1 0 (3) 1 5 (3) 1 5 (1 ) 5 (1 ) 5 F l e x i b i l i t y (4) (3) 12 (3) 1 2 (2) 8 (1 ) 4 (1 ) 4 C a p i t a l Cost (5) (1) 5 ( 1 ) 5 (3) 1 5 (1 ) 5 (1 ) 5 O p e r a t i o n s C o s t s (5) (1 ) 5 (1 ) 5 (3) 1 5 (3) 1 5 (3) 15 TOTALS 44 49 73 45 45 222 k. Energy I n t e n s i t y . Low energy input i s a major p r i o r i t y , p a r t l y because the s i t e i s remote enough to make energy inputs expensive, but mainly because a w e l l designed g r a v i t y flow system should p r e c l u d e the pumping c o s t s which are a major consumer of energy on f i s h farms. One o p e r a t i o n that probably must be run by e l e c t r i c i t y (although a c l e v e r i n v e n t o r c o u l d r i g up a g r a v i t y timed and operated d e v i c e ) i s an automatic fe e d i n g system. The advantage of frequent feeding i n promoting growth i s worth the t r o u b l e of i n s t a l l i n g a small e l e c t r i c a l generator to run the timers and feeders. However, u n i t s are now a v a i l a b l e which are b a t t e r y powered, r e q u i r i n g only p e r i o d i c c h a r g i n g at the ranch proper. Demand feeders should be used to supplement the automatic feeders as much as p o s s i b l e , s i n c e t h e i r energy requirements are n i l . I t i s recommended that e i t h e r a g r a v i t y powered feeding system be d e v i s e d or b a t t e r y powered e l e c t r i c a l system be i n s t a l l e d , supplemented by demand fee d e r s . 1 . Labour I n t e n s i t y . Low labour input i s a must to the design's acceptance, not only from a c o s t viewpoint but a l s o because r e l i a b l e , semi-s k i l l e d labour i s hard to f i n d and keep i n the area in q u e s t i o n . The most s u i t a b l e o p e r a t i o n would be one which r e q u i r e d minimal p e r i o d i c i n s p e c t i o n and maintenance by the labour f o r c e a l r e a d y at hand. The d e l i c a t e nature of t r o u t T a b l e 22. Energy And Labour I n p u t s E v a l u a t i o n Measures Low H i g h Low High Labour Labour Energy Energy Water Wastage (3) (2) 6 (3) 9 (2) 6 (3) 9 Equipment/machine (4) (3) 12 (1 ) 4 (3) 1 2 (2) 8 Manpower C o n f l i c t (4) (3) 1 2 (1 ) 4 (2) 8 (1 ) 4 F i s h P r o d u c t i o n (5) (2) 1 0 (3) 15 (2) 1 0 (3) .15 R e l i a b i l i t y (5) (2) 1 0 (3) 1 5 (3) 1 5 (2) 10 F l e x i b i l i t y (4) (3) 1 2 (1 ) 4 (3) 1 2 (1 ) 4 C a p i t a l Cost (5) > 5 (2) 1 0 (3) 1 5 ( 1 ) 5 O p e r a t i o n s C o s t s (5) (3) 1 5 (1) 5 (3) 1 5 (1 ) 5 Revenue (5) (1 ) 5 (2) 1 0 (2) 1 0 (3) 15 TOTALS 87 76 1 03 65 224 f a r m i n g , however, would p r o b a b l y r e q u i r e at l e a s t one f u l l - t i m e manager who had a c c e s s t o h e l p , when needed, from the r e s t of the ranch s t a f f . T h i s i s a l s o a f a c t o r i n f a c i l i t y s c a l i n g , s i n c e even a p r o t o t y p e farm s h o u l d be a b l e t o g e n e r a t e enough income t o break even p l u s support one f u l l t i m e , w e l l - t r a i n e d manager. I t i s recommended t h a t one manager, w e l l v e r s e d i n f i s h c u l t u r e , be h i r e d t o s u p e r v i s e c o n s t r u c t i o n and run the f a c i l i t y . F. C o n c e p t u a l Design a. O u t l i n e . From the d e s i g n d e c i s i o n s made f o r the system subcomponents (Table 2 3 ) , a d e s c r i p t i o n of the best c o n c e p t u a l d e s i g n f o r an a q u a c u l t u r a l f a c i l i t y t o be b u i l t on the Guichon Ranch can now be o u t l i n e d . Water i s d i v e r t e d from Moore Creek and i s p i p e d t o a row of p l a s t i c l i n e d raceways. The water i s a e r a t e d b e f o r e e n t e r i n g each raceway and passes through a b i o l o g i c a l f i l t e r a f t e r each t h i r d r e u s e . The water d e l i v e r y and t r e a t m e n t system i s g r a v i t y f e d . Rainbow t r o u t a r e r a i s e d on commercial f e e d s , d i s t r i b u t e d from an a u t o m a t i c f e e d i n g system powered by b a t t e r i e s and the f i s h t h e m s e l v e s . A f u l l - t i m e manager l o a d s the f e e d b i n s , c hecks the c o n d i t i o n of the f i s h and m o n i t o r s the water q u a l i t y 2 2 5 T a b l e 2 3 . S y s t e m C o m p o n e n t s S e l e c t e d 1 . W a t e r S o u r c e C r e e k 2 . W a t e r C o n v e y a n c e C r e e k 3 , P e r c e n t W a t e r U s e P a r t i a l 4 . W a t e r R e u s e S e r i a l 5 . W a t e r T r e a t m e n t F i l t e r No H e a t i n g P a s s i v e A e r a t i o n 6 . F i s h T y p e T r o u t 7 . E n c l o s u r e P l a s t i c R a c e w a y 8 . F i s h F o o d Commerc i a l 9 . E n e r g y S o u r c e G r a v i t y 1 0 . L a b o u r I n p u t Low 1 1 . E n e r g y I n p u t Low 226 and f l o w , a d j u s t i n g water i n f l o w r a t e , f e e d i n g r a t e and s t o c k i n g d e n s i t y t o m a i n t a i n the best r e a r i n g c o n d i t i o n s . F i g u r e 29 shows an o p e r a t i o n p r o c e s s c h a r t f o r the r e a r i n g o p e r a t i o n . b. System S i z i n g . The purpose of t h i s s e c t i o n i s t o take the g e n e r a l d e s c r i p t i o n and t u r n i t i n t o numbers. The major l i m i t a t i o n t o f i s h c u l t u r e a t t h i s l o c a t i o n i s the water t e m p e r a t u r e . S i n c e t r o u t do not grow a p p r e c i a b l y i n water below 5 ° C , the growing season f o r t h i s p r o j e c t based on the p r o j e c t e d t e m p e r a t u r e s w i l l be from mid March t o e a r l y November each y e a r . To a v o i d g e t t i n g i n v o l v e d i n o v e r w i n t e r i n g the f i s h , they s h o u l d be market s i z e by the end of the growing season. To c a l c u l a t e the s i z e t h a t f i s h must be s t o c k e d a t t o get market s i z e d h a r v e s t , the F i s h Growth model was used. The model was run i n r e v e r s e , t h a t i s the s p e c i f i c growth r a t e was made n e g a t i v e , such t h a t the f i s h "ungrew" from 300 grams backwards over time (see the d i s c u s s i o n i n the "Design of Models" c h a p t e r f o r e x p l a n a t i o n of the model and i t s d y n a m i c s ) . T h i s s i m u l a t i o n ( F i g u r e 30) r e v e a l e d t h a t f i n g e r l i n g s of a t l e a s t 85-90 gram s i z e must be s t o c k e d i f they are e x p e c t e d t o grow t o market s i z e d u r i n g one growing season. The F i s h Growth model was then r e - r u n i n the r i g h t d i r e c t i o n t o get e s t i m a t e s of f i s h s i z e a t v a r i o u s t i m e s over the year and then the Load Rate c a l c u l a t i o n s were performed on each s e t of monthly c o n d i t i o n s t o determine Fingerling Input Feed Storage " 0 Prepare Site 0 Feeding Delay for Growth Are Fish Crowded? Yes Are Fish iMarketable? Yes Xs Market Available? Yes 0 Inspection Sort to Other Ponds Inspection Reduce to Maintenance Ration Inspection Harvest & Process Fish 0 Winterize Site F i g u r e 29. O p e r a t i o n s P r o c e s s C h a r t f o r F a c i l i October September August July June May April March Rearing Period Figure 30. Reverse Growth of Trout Over Growing Season. T h i s s i m u l a t i o n i n d i c a t e s t h a t 85 gram t r o u t must be stocked i n A p r i l . to CO 229 f l o w and volume l o a d i n g r a t e s . The number of f i s h t h a t can be h e l d i n a 65 c u b i c meter swimming p o o l was c a l c u l a t e d from the maximum f i s h s i z e (300 grams) and the maximum l o a d i n g r a t e (32 k i l o g r a m s per c u b i c m e t e r ) . Flow and volume of water r e q u i r e d a t s e v e r a l times d u r i n g the year were then c a l c u l a t e d (from f i s h number, f i s h s i z e and l o a d r a t e s ) and demand c u r v e s p l o t t e d ( F i g u r e 39, T a