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A comparison of growth rates of rainbow trout in culture tanks with different hydraulic characteristics Vizcarra, Angelito T. 1982

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A COMPARISON OF GROWTH RATES OF RAINBOW TROUT IN CULTURE TANKS WITH DIFFERENT HYDRAULIC CHARACTERISTICS by ANGELITO T. VIZCARRA B.S.C.E., Mindanao St a t e U n i v e r s i t y , 1971 A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF APPLIED SCIENCE i n THE FACULTY OF GRADUATE STUDIES Department Of B i o - r e s o u r c e E n g i n e e r i n g We accept t h i s t h e s i s as conforming to the r e q u i r e d standard THE UNIVERSITY OF BRITISH COLUMBIA A p r i l 1982 © A n g e l i t o T. V i z c a r r a , 1982 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 of the requirements for an advanced degree at the U n i v e r s i t y of B r i t i s h Columbia, I agree that 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 that p e r m i s s i o n f o r e x t e n s i v e copying of 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 of my Department or 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 that 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 gain 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 . A n g e l i t o T. V i z c a r r a Department of BIO-RESOURCE ENGINEERING The U n i v e r s i t y of B r i t i s h Columbia 2075 Wesbrook Place Vancouver, Canada V6T 1W5 Date: APRIL 22,1982 i i A b s t r a c t The d i f f e r e n t i a l performance of rainbow t r o u t (Salmo g a i r d n e r i ) i n small s c a l e models of c i r c u l a r c r o s s -s e c t i o n raceways, c i r c u l a r tanks, and v e r t i c a l tanks were documented. The experimental tanks had a water volume of 47 l i t e r s each. A constant head r e s e r v o i r s u p p l i e d water to the c u l t u r e tanks e q u a l l y at a flow r a t e of 5 1/min. The f i s h with i n i t i a l weight of 9.08 g (9.11 cm) were reared through 4 p e r i o d s of 42 days each (August 14, 1981 January 31, 1982). For every p e r i o d , the tanks were stocked with the same number of f i s h . A l l f i s h l o t s were fed equal d a i l y r a t i o n at the same feed i n g frequency. The feed r a t i o n ranged from 3.0% to 0.8% body weight per day. The water temperature f l u c t u a t e d from 17°C to 4°C. Water pH was c o n s i s t e n t l y on the a c i d s i d e with a low l e v e l of 5.1. T o t a l ammonia l e v e l s were n e g l i g i b l e with a high of 0.73 mg/1. The h e a v i e s t s t o c k i n g d e n s i t y a t t a i n e d was 171.68 kg/m3. The c a l c u l a t e d pond l o a d i n g i n d i c e s , Wi, ranged from -0.63 to 1.45 kg/l-cm while the c a r r y i n g c a p a c i t i e s ranged from 0.35 to 1.61 kg/l/min. The average weight of the h e a v i e s t f i s h l o t at the end of the study was 101.80 g (19.94 cm). The tanks and growing p e r i o d s were compared on the b a s i s of percent weight g a i n , l e n g t h g a i n , c o n d i t i o n f a c t o r , and feed c o n v e r s i o n r a t i o . The two-way a n a l y s i s of v a r i a n c e showed s i g n i f i c a n t v a r i a t i o n from tank to tank and from growing p e r i o d to growing p e r i o d i n everyone of these growth parameters. For a l l 4 p e r i o d s , the percent weight gains and l e n g t h gains in the v e r t i c a l tanks were c o n s i s t e n t l y the h i g h e s t . The raceways gave the l e a s t g a i n s . Feed conversion e f f i c i e n c i e s were h i g h e s t i n the v e r t i c a l tanks and l e a s t i n the raceways. Feed conversion r a t i o s v a r i e d from 1.23 to 2.93 kg of feeds/kg of f i s h . For a given l e n g t h , the f i s h i n the v e r t i c a l and c i r c u l a r tanks were heavier than those i n the raceways. The observed c o n d i t i o n f a c t o r s ranged from 0.0123 to 0.0133 g/cm 3. The r e s u l t s of t r a c e r experimentation confirmed that the c i r c u l a r tanks approximated an i d e a l mixed flow and that the raceways approximated an i d e a l plug flow. The v e r t i c a l tanks e x h i b i t e d h y d r a u l i c p r o p e r t i e s s i m i l a r to those of the c i r c u l a r tanks i n d i c a t i n g mixed flow c o n d i t i o n s in the tanks. C o r r e l a t i o n between growth r a t e s and h y d r a u l i c c h a r a c t e r i s t i c s i n d i c a t e d that growth ra t e s are higher i n mixed flow tanks than i n plug flow tanks. The h y d r a u l i c s t u d i e s a l s o showed that f i s h biomass and a c t i v i t y s i g n i f i c a n t l y a f f e c t e d the h y d r a u l i c c h a r a c t e r i s t i c s of the c u l t u r e tanks. Dr. John W. Zahradnik T h e s i s S u p e r v i s o r i v Table of Contents A b s t r a c t i i L i s t of Tables v i _ L i s t of F i g u r e s v i i Acknowledgement v i i i I. INTRODUCTION 1 I I . LITERATURE REVIEW 3 1. WATER QUALITY CRITERIA FOR TROUT CULTURE 3 1. WATER TEMPERATURE 3 2. DISSOLVED OXYGEN 4 3. AMMONIA-N 5 4. pH 5 2. GROWTH FACTORS 6 1. FEED RATION AND FEEDING FREQUENCY 6 2. FISH SIZE .• 7 3. WATER TEMPERATURE 7 4. WATER VELOCITY 8 5. POND LOADING 9 3. MEASURES OF GROWTH 11 1 . GROWTH RATE 11 2. FEED CONVERSION RATIO 11 3. FISH CONDITION FACTOR 12 4. GROWTH PROGRAMMING 13 5. TANKS FOR TROUT CULTURE 14 1 . RACEWAY 14 2. CIRCULAR TANK • 14 3. RECTANGULAR CIRCULATING POND 15 4. VERTICAL TANK 16 6. GROWTH COMPARISON STUDIES 16 7. HYDRAULIC CHARACTERISTICS OF CULTURE TANKS 19 8. MODEL THEORY 2 2 I I I . THEORY FORMULATION 2 4 1. PROPOSITIONS 24 2. ASSUMPTIONS 25 3. INFERENCES 25 IV. MATERIALS AND METHODS 26 1 . TEST FISH 26 2. FACILITIES 27 1 . TEST TANKS 27 2. CONSTANT HEAD RESERVOIR 28 3. WATER QUALITY MEASUREMENTS 34 1. WATER TEMPERATURE 34 2. DISSOLVED OXYGEN 34 3. pH 35 4. AMMONIA-N 35 5. DATA ANALYSIS 35 4. GROWTH STUDIES 36 1. PHASE I (AUGUST 14 - SEPTEMBER 24, 1981) 37 2. PHASE II (SEPTEMBER 26 - NOVEMBER 6, 1981) ...39 3. PHASE I I I (NOVEMBER 8 - DECEMBER 19, 1981) ...40 4. PHASE IV (DECEMBER 21, 1981 - JANUARY 31, 1982) 40 V 5. DATA ANALYSIS 41 5. HYDRAULIC STUDIES 41 1. VELOCITY MEASUREMENTS 42 2. TRACER EXPERIMENTS 42 3. DATA ANALYSIS 44 V. RESULTS AND DISCUSSION 45 1. WATER QUALITY 45 1 . TEMPERATURE 45 2. DISSOLVED OXYGEN 46 3. pH 53 4. AMMONIA-N 59 2. MORTALITIES 65 3. GROWTH STUDIES . 66 1 . WEIGHT GAIN 66 2. LENGTH GAIN 74 3. FEED CONVERSION RATIO 77 4. CONDITION FACTOR 80 5. LOADING DENSITIES 82 4. HYDRAULIC STUDIES 85 1. VELOCITY MEASUREMENTS 85 2. TANK CLASSIFICATION 86 3. HYDRAULIC CHARACTERISTICS 91 5. CORRELATION BETWEEN HYDRAULIC CHARACTERISTICS AND GROWTH RATES 103 V I . CONCLUSIONS 104 V I I . RECOMMENDATIONS FOR FUTURE WORK 105 BIBLIOGRAPHY 107 APPENDIX A - FLOW CONTROL AND DISCHARGE MEASUREMENTS 113 APPENDIX B - COMPOSITION OF NEW AGE FISH FEEDS 114 APPENDIX C - THE "HYDRAULIC" COMPUTER PROGRAM 115 APPENDIX D - WEIGHT AND LENGTH MEASUREMENTS 120 APPENDIX E - ANALYSIS OF VARIANCE TABLES 124 APPENDIX F - L I S T OF ABSORBANCES 138 APPENDIX G - SCALING CONSIDERATIONS 156 VI L i s t of Tables I. Comparative e f f i c i e n c y r a t i n g s of four pond types. 18 I I . Dimensions of t e s t tanks 27 I I I . Phase I - Feed, temperature, and d i s s o l v e d oxygen. 49 IV. Phase II - Feed, temperature, and d i s s o l v e d oxygen. 50 V. Phase III - Feed, temperature, and d i s s o l v e d oxygen. 51 VI. Phase IV - Feed, temperature, and d i s s o l v e d oxygen. 52 VII . Phase I - pH 55 VIII . Phase II - pH 56 IX. Phase III - pH 57 X. Phase IV - pH 58 XI. Phase I - Ammonia-N 61 XII. Phase II - Ammonia-N 62 X I I I . Phase III - Ammonia-N 63 XIV. Phase IV - Ammonia-N 64 XV. Average weight and l e n g t h gains 73 XVI. Feed c o n v e r s i o n r a t i o s and c o n d i t i o n f a c t o r s 78 XVII. S t o c k i n g d e n s i t i e s and c a r r y i n g c a p a c i t i e s 84 XVIII .Hydraulic p r o p e r t i e s of c i r c u l a r tanks 95 XIX. H y d r a u l i c p r o p e r t i e s of v e r t i c a l tanks 96 XX. H y d r a u l i c p r o p e r t i e s of raceways 97 v i i L i s t of F i g u r e s 1. A schematic diagram of the experimental f a c i l i t i e s . .29 2. The c i r c u l a r t e s t tank 30 3. The v e r t i c a l t e s t tank 31 4. The c i r c u l a r c r o s s - s e c t i o n raceway t e s t tank 32 5. The constant head r e s e r v o i r 33 6. Percent weight gains (dW/Wo) for the c u l t u r e tanks p l o t t e d a g a i n s t time. 72 7. Length gains f o r the c u l t u r e tanks p l o t t e d a g a i n s t t ime 76 8. Feed c o n v e r s i o n r a t i o s f o r the c u l t u r e tanks p l o t t e d a g a i n s t time 79 9. C o n d i t i o n f a c t o r s f o r the c u l t u r e tanks p l o t t e d a g a i n s t time 81 10. E-curves with 0 f i s h f o r the experimental and i d e a l -tanks 87 11. F-curves with 0 f i s h f o r the experimental and i d e a l tanks 88 12. I-curves with 0 f i s h f o r the experimental and i d e a l tanks 89 13. Mean re s i d e n c e times f o r tanks and phases p l o t t e d a g a i n s t number of f i s h 98 14. Probable flowing-through times f o r tanks and phases p l o t t e d a g a i n s t number of f i s h 99 15. Dead volumes f o r tanks and phases p l o t t e d a g a i n s t number of f i s h i 100 16. V a r i a n c e s f o r tanks and phases p l o t t e d a g a i n s t number of f i s h 101 17. I n i t i a l dye appearances f o r tanks and phases p l o t t e d a g a i n s t number of f i s h 102 v i i i Acknowledgement The author i s s i n c e r e l y g r a t e f u l to the members of h i s committee, Dr. Sie-Tan Chieng, Dr. A n t a l Kozak, Dr. V i c t o r Lo, and Dr. John W. Zahradnik (Chairman) f o r t h e i r i n v a l u a b l e guidance; to the I n t e r n a t i o n a l Development Research Center of Canada (IDRC) and the Aquaculture Department of the Southeast Asian F i s h e r i e s Development Center (SEAFDEC) f o r t h e i r f i n a n c i a l support; to Mi c h a e l F a t t o r i , Sam Gopaul, N e i l Jackson, Edwin Kwong, Dr. Ping L i a o , Jurgen Pehlke, and Rolando P l a t o n f o r t h e i r t e c h n i c a l a s s i s t a n c e ; and, f i n a l l y , to h i s wi f e , Eleanor, and h i s c h i l d r e n , Anna P a u l i n e , Karen M i c h e l l e , and Aaron David, f o r the moral support and i n s p i r a t i o n . 1 I . INTRODUCTION There are v a r i o u s designs of tanks used i n the i n t e n s i v e c u l t u r e of rainbow t r o u t (Salmo g a i r d n e r i ) . Every design i s equipped with a d i s t i n c t water i n f l o w - o u t f l o w system. Due to t h i s d i s s i m i l a r i t y and the b a s i c d i f f e r e n c e s i n geometric shape, the flow p a t t e r n s o b t a i n i n g i n any one tank i s d i f f e r e n t from those found i n the o t h e r s . I t has been shown that the flow p a t t e r n s a f f e c t the b i o l o g i c a l and chemical components of water in the tank (Burrows & Chenoweth, 1955; Larmoyeux et a l . , 1973; Westers & P r a t t , 1977). I f , i n t u r n , water c o n d i t i o n s s i g n i f i c a n t l y a f f e c t the growth and c o n d i t i o n of the f i s h , i t would then be l i k e l y that d i f f e r e n t types of tank produce d i f f e r e n t growth r a t e s and f i s h c o n d i t i o n s . In t h i s study, rainbow t r o u t was reared i n d i f f e r e n t tank shapes under s i m i l a r c o n d i t i o n s of input-water q u a l i t y . Other f a c t o r s known to a f f e c t growth r a t e s were maintained at the same l e v e l s f o r a l l tanks. The r a t i o n a l e was t h a t , i f the experiment r e s u l t s i n s i g n i f i c a n t v a r i a t i o n i n growth r a t e s from tank to tank, such v a r i a t i o n would be the e f f e c t of the d i f f e r e n c e s in the h y d r a u l i c c h a r a c t e r i s t i c s of the t e s t tanks. Three types of small s c a l e r e a r i n g tanks were i n v e s t i g a t e d . These were the c i r c u l a r tank, the v e r t i c a l u n i t , and the c i r c u l a r c r o s s - s e c t i o n raceway. The c i r c u l a r tank i s t y p i c a l of mixed flow v e s s e l s i n which the incoming water i s mixed with the o r i g i n a l water i n the tank r e s u l t i n g i n f a i r l y homogeneous c o n d i t i o n s throughout the tank. The raceway approximates a plug-flow v e s s e l i n which a s l u g of water introduced i n t o the 2 tank w i l l emerge out of the tank a l s o as a s l u g . The flow p a t t e r n s i n a v e r t i c a l u n i t have not yet been w e l l e s t a b l i s h e d . The growth r a t e s t u d i e s c o n s i s t e d of r e a r i n g rainbow t r o u t i n the t e s t tanks through four p e r i o d s of s i x weeks each. The tanks were designed to h o l d equal water volume and they were s u p p l i e d with equal water flow r a t e s . A s i n g l e r e s e r v o i r s u p p l i e d water to a l l the tanks to ensure s i m i l a r input-water q u a l i t y . A l l f i s h l o t s were fed equal r a t i o n s although the d a i l y r a t i o n was a d j u s t e d with the changing water temperature and the i n c r e a s i n g f i s h s i z e . At the beginning of every p e r i o d , the tanks were stocked with the same number of f i s h . At the end of every p e r i o d , the weight and l e n g t h of random samples of f i s h were measured. The percent weight gains, l e n g t h gains, feed c o n v e r s i o n r a t i o s , and c o n d i t i o n f a c t o r s were then compared. The study a l s o i n c l u d e d an e v a l u a t i o n and comparison of the h y d r a u l i c c h a r a c t e r i s t i c s of the t e s t tanks by the impulse-response method of t r a c e r experimentation ( L e v e n s p i e l , 1962; Wen & Fan, 1975). A dose of malachyte green was i n t r o d u c e d i n t o each tank and the c o n c e n t r a t i o n of the dye l e a v i n g the tank was monitored at f i x e d time i n t e r v a l s . From the t i m e - c o n c e n t r a t i o n data, the age d i s t r i b u t i o n curves were p l o t t e d . From these curves, the tank h y d r a u l i c c h a r a c t e r i s t i c s were evaluated in terms of the mean reside n c e time, dead volume, probable f l o w i n g -through time, v a r i a n c e , and the time of the i n i t i a l appearance of dye at the o u t l e t . F i n a l l y , the a t t a i n e d growth r a t e s were c o r r e l a t e d with the observed h y d r a u l i c c h a r a c t e r i s t i c s of the tanks. 3 I I . LITERATURE REVIEW 1. WATER QUALITY CRITERIA FOR TROUT CULTURE For flow-through f i s h c u l t u r e systems, the more s i g n i f i c a n t water q u a l i t y parameters are temperature, d i s s o l v e d oxygen, ammonia, and pH. 1. WATER TEMPERATURE Water temperature a f f e c t s the s o l u b i l i t y of oxygen i n water, i . e . , as the water temperature goes up, the d i s s o l v e d oxygen c o n c e n t r a t i o n i n the water goes down. More s i g n i f i c a n t l y , water temperature r e g u l a t e s the rate of d i g e s t i o n and metabolism i n the f i s h . A decrease i n these p h y s i o l o g i c a l processes i s a s s o c i a t e d with a drop i n the water temperature. In g e n e r a l , the uptake r a t e of oxygen by f i s h i s d i r e c t l y p r o p o r t i o n a l to the water temperature. Klontz e t . a l . (1978) termed the p r e f e r r e d water temperature of a f i s h s p e c i e s i t s standard environmental temperature (SET). The d e f i n i t i o n i m p l i e s t h a t , i f a l l f a c t o r s a f f e c t i n g growth except temperature were kept constant, the f i s h w i l l a t t a i n i t s maximum growth rate at the SET. They estimated that the SET f o r t r o u t i s 15°C. 4 2. DISSOLVED OXYGEN D i s s o l v e d oxygen p l a y s a very important r o l e i n the c u l t u r e of t r o u t . Low l e v e l s of d i s s o l v e d oxygen can a d v e r s e l y a f f e c t swimming performance, growth r a t e , food consumption, feed c o n v e r s i o n e f f i c i e n c y , and r e s i s t a n c e to d i s e a s e , p a r a s i t e s and t o x i c a n t s . Oxygen consumption i s dependent upon water temperature, f i s h s i z e , l e v e l of a c t i v i t y , feed r a t i o n , and the presence of carbon d i o x i d e and ammonia. High temperatures r e s u l t i n high oxygen consumption (Rao, 1971). As the f i s h gains s i z e , oxygen consumption per u n i t biomass decreases (Klontz e t . a l . , 1978). Oxygen consumption i n c r e a s e s with a c t i v i t y and feed r a t i o n l e v e l ( B r e t t , 1965; 1976). Carbon d i o x i d e i n t e r f e r e s with r e s p i r a t i o n (Sigma Resources C o n s u l t a n t s , 1979) and ammonia i n h i b i t s the a b s o r p t i o n of oxygen (Brockway, 1950). Jones (1964) a l s o hypothesized t h a t , below a c e r t a i n c r i t i c a l l e v e l , the rate of oxygen consumption i s dependent upon the oxygen c o n c e n t r a t i o n i n the water. Most s t u d i e s i n d i c a t e that the lowest safe l e v e l f o r t r o u t i s 5 mg/1. No upper l i m i t has yet been p i n p o i n t e d . The economic f e a s i b i l i t y of using pure oxygen f o r a e r a t i o n j u s t i f i e s more s t u d i e s i n t h i s d i r e c t i o n . Gas bubble d i s e a s e occurrence i s f e a r e d at l e v e l s above s a t u r a t i o n although i t has been repo r t e d that t r o u t was c u l t u r e d at 165% s a t u r a t i o n l e v e l without any problem (Speece, 1981). 5 3. AMMONIA-N High l e v e l s of ammonia can cause g i l l damage, r e d u c t i o n of the c a p a c i t y of the blood to c a r r y oxygen, and other h i s t o l o g i c a l damages (C o l t & Armstrong, 1981). I t leads to reduced growth r a t e s (Burrows, 1964). At e x c e s s i v e c o n c e n t r a t i o n s , i t r e s u l t s i n m o r t a l i t y . Ammonia i s a product of the b i o l o g i c a l degradation of nitrogenous organic matter. As such, i t i s found even i n u n p o l l u t e d waters. Being the end product of p r o t e i n metabolism in f i s h , i t s c o n c e n t r a t i o n i n r e a r i n g tanks accumulates. Ammonia d i s s o l v e s i n water to form both i o n i z e d and u n - i o n i z e d s p e c i e s . I t s t o x i c i t y i s mainly a t t r i b u t e d to i t s u n - i o n i z e d form, NH 3. The degree of i o n i z a t i o n of ammonia i s a f u n c t i o n of the pH and temperature ( T r u s s e l , 1972; Thurston e t . a l . , 1974). I t has been suggested that the NH 3 c o n c e n t r a t i o n i n t r o u t and salmonid r e a r i n g tanks should not exceed 0.002 mg/1 (Sigma Resource C o n s u l t a n t s , L t d . , 1979). T h i s i s e q u i v a l e n t to a t o t a l ammonia (NH 3 + N H „ M c o n c e n t r a t i o n of 1.1 mg/1 at a temperature of 10°C and a pH of 7.0. 4. 2M pH i s a • widely accepted measure of the hydrogen ion c o n c e n t r a t i o n i n water. I t s relevance l i e s i n i t s e f f e c t on the t o x i c i t y of ammonia, n i t r i t e s , metals, and other contaminants. A study by E l l i s e t . a l . (1946) showed that the normal pH values found i n t r o u t r e a r i n g f a c i l i t i e s range from 6.7 to 8.6. However, a c r i t e r i o n adopted by the Environmental P r o t e c t i o n 6 Agency (1976) s t a t e s that a pH range of 5 to 9 i s not d i r e c t l y l e t h a l to f i s h although the t o x i c i t y of some p o l l u t a n t s may be markedly a f f e c t e d w i t h i n t h i s range. 2. GROWTH FACTORS The growth r a t e of t r o u t i s thought to be a f f e c t e d by a l o t of f a c t o r s , e.g., water temperature, c a r e , s p e c i e s , s t r a i n , d i e t , feed r a t i o n and feeding frequency, h e a l t h , sexual m a t u r i t y , 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 , water v e l o c i t y , l o a d i n g d e n s i t y , and season. Among these, H a s k e l l (1959) c o n s i d e r e d water temperature, s p e c i e s , and feed i n g l e v e l as the more s i g n i f i c a n t : S t a u f f e r (1973) concluded t h a t , f o r a given s p e c i e s and d i e t , the f a c t o r s of feed r a t i o n , f i s h s i z e , and water temperature have the most i n f l u e n c e i n growth. 1. FEED RATION AND FEEDING FREQUENCY Feed i s the p r i n c i p a l source of energy necessary f o r f i s h growth and maintenance. D a i l y feed r a t i o n i s governed by water temperature and f i s h s i z e . As the water temperature drops, the r a t i o n i s reduced. As the f i s h grow i n s i z e , the r a t i o n i s a l s o reduced. Most feedi n g guides are based on these r e l a t i o n s h i p s . T y p i c a l examples are found i n the l i t e r a t u r e . Most feed manufacturers i s s u e t h e i r own v e r s i o n of fe e d i n g c h a r t s . Buterbaugh & Willoughby (1967) extended H a s k e l l ' s feeding formula (1959) to come out with a feeding guide based on f i s h s i z e and a hatchery co n s t a n t . The hatchery constant i s evaluated on the b a s i s of 7 h i s t o r i c a l growth r a t e s , feed c o n v e r s i o n e f f i c i e n c i e s , and water temperatures. 1 I n v a r i a b l y , feed r a t i o n i s expressed as a percentage of the f i s h body weight per day. The frequency of feeding i n a day i s d i c t a t e d by the s i z e of the f i s h . Small f i s h , due to t h e i r small stomach c a p a c i t y , are fed small amounts of feed f r e q u e n t l y . As the f i s h grow, the amount of food per feeding i s i n c r e a s e d and the frequency of feeding i s reduced with longer i n t e r v a l s between f e e d i n g s . 2. FISH SIZE The growth laws of Medawar (1945) s t a t e that the s p e c i f i c r a t e of growth decreases at a de c r e a s i n g r a t e as the f i s h i n c r e a s e s i n age and that the s i z e of a f i s h i s a monotonic i n c r e a s i n g f u n c t i o n of i t s age. Thus, the s p e c i f i c growth rate decreases as f i s h i n c r e a s e s i n s i z e and age^ For t r o u t , the percent gain decreases as the f i s h i n c r e a s e s i n s i z e ( H a s k e l l , 1948). 3. WATER TEMPERATURE A review of t h i s f a c t o r was presented e a r l i e r i n t h i s c hapter. In a d d i t i o n , i t i s gathered t h a t , at optimum water temperature, t r o u t can gain 3.8 centimeters i n l e n g t h i n one month. F u r t h e r , f o r each °C decrease from the t r o u t standard For h a t c h e r i e s with constant water temperatures: Hatchery constant = 300 X Feed conve r s i o n r a t i o X dL where dL i s observed d a i l y i n c r e a s e i n len g t h (Buterbaugh & Willoughby, 1967). 8 environmental temperature of 15°C, there i s a corresponding 9% decrease i n growth rate (Klontz e t . a l . , 1978). T h i s r u l e of thumb was found to concur very w e l l with the concept of temperature u n i t s (TU) proposed by H a s k e l l (1959). In S.I. u n i t s , TU(month) = Average monthly water temperature (°C) - 3.67°C The TU concept i m p l i e s that the number of TU's r e q u i r e d by t r o u t to gain a u n i t l e n g t h i s c o n s t a n t . 4. WATER VELOCITY Water v e l o c i t y i s the d r i v i n g f o r c e f o r f i s h swimming a c t i v i t y . In t h i s sense, i t i s a f a c t o r to growth r a t e . As f i s h absorbs energy from feeds, p a r t of that energy i s expended i n swimming a c t i v i t y and the r e s t i s a s s i m i l a t e d as growth. With t h i s s i m p l i f i e d model, i t f o l l o w s t h a t , f o r a given energy i n t a k e , with l e s s energy r e q u i r e d f o r swimming, the more energy i s a v a i l a b l e f o r growth. L e i t r i t z & Lewis (1980) noted that feed c o n v e r s i o n i s normally b e t t e r i n l a r g e , deep, s t i l l pools where the f i s h are at r e s t most of the time than in narrow, s w i f t ponds where the f i s h spends a l o t of energy i n m a i n t a i n i n g i t s p o s i t i o n . The maximum v e l o c i t y which can be s u s t a i n e d by f i s h v a r i e s a c c o r d i n g to s p e c i e s and s i z e . For sockeye f i n g e r l i n g s (Oncorhynchus nerka), t h i s l i m i t i n g v e l o c i t y i s 4 body lengths per second ( B r e t t , 1964). For f a l l chinook f i n g e r l i n g s (Oncorhynchus tshawytscha), i t i s 4.6 body lengths 9 per second (Burrows & Chenoweth, 1970). Fry and Cox (1970) found that rainbow t r o u t (Salmo q a i r d n e r i ) , 6-20 cm i n fork l e n g t h (4-100 g), has a speed-weight exponent of 0.13 at 10°C. The study showed that a 10 g f i s h c o u l d swim at approximately 9 body le n g t h s per second whereas a 100 g f i s h has a c r u i s i n g speed of 5.5 body lengths per second. The authors noted the p o s s i b i l i t y that a higher r e a r i n g temperature was a s s o c i a t e d with a higher swimming speed. On the other hand, water v e l o c i t y c o n t r i b u t e s to muscle tone and improved stamina in salmonids (Posten e t . a l . , 1969). At higher v e l o c i t i e s , b e t t e r feed d i s t r i b u t i o n i s achieved and s e l f - c l e a n i n g e f f i c i e n c y i s enhanced. 5. POND LOADING Low d i s s o l v e d oxygen l e v e l s and high ammonia c o n c e n t r a t i o n can r e s u l t i n reduced growth r a t e s . Since e x c e s s i v e f i s h loads can b r i n g about these d e t e r i o r a t i o n i n water q u a l i t y , pond l o a d i n g i s another f a c t o r to growth r a t e . K i n c a i d e t . a l . (1976) and Brauhn e t . a l . (1976) working on c i r c u l a r tanks and Kilambi e t . a l . (1977) working on cages r e p o r t e d that changes i n s t o c k i n g d e n s i t y a f f e c t e d t r o u t growth, y i e l d in biomass, and feed c o n v e r s i o n e f f i c i e n c y . There are s e v e r a l p u b l i s h e d methods f o r determining the maximum biomass of f i s h that can be s u s t a i n e d i n a tank without negative e f f e c t on growth r a t e s ( H a s k e l l , 1955; Willoughby, 1968; E l l i o t t , 1969; P i p e r , 1970; Westers, 1970; L i a o , 1971; K l o n t z e t . a l . , 1978). Each of these methods takes i n t o account 10 two or more of the f o l l o w i n g f a c t o r s , namely, d i s s o l v e d oxygen, fe e d i n g r a t e , f i s h weight, f i s h l e n g t h , growth r a t e , oxygen uptake, pond volume, s i t e e l e v a t i o n , water i n f l o w , water changes per hour, and water temperature. A review of these methods can be found in Klon t z e t . a l . (1978). Pond l o a d i n g values are oftentimes reported i n terms of s t o c k i n g d e n s i t y (kg/m 3) or c a r r y i n g c a p a c i t y (kg/l/min). These measures do not take i n t o account e i t h e r f i s h s i z e or water temperature. P u b l i s h e d s t o c k i n g d e n s i t y values range from 16 to 139 kg/m3 and c a r r y i n g c a p a c i t i e s range from 0.4 to 5.0 kg/l/min. The repor t e d range of values v a r i e s f o r d i f f e r e n t types of tank. Based on H a s k e l l ' s (1955) concept that the maximum p e r m i s s i b l e weight of f i s h i n a given pond i s d i r e c t l y p r o p o r t i o n a l to t h e i r l e n g t h , Piper (1970; 1972) proposed the use of a l o a d i n g f a c t o r (F) which c o n s i d e r s the len g t h of the f i s h . F i s in S.I. u n i t s of kilograms of f i s h per centimeter of le n g t h per l i t e r per minute of water flow. Values of F i n E n g l i s h u n i t s are t a b u l a t e d under d i f f e r e n t water temperatures and d i f f e r e n t a l t i t u d e s i n Piper (1970). Klontz e t . a l . (1978) expanded P i p e r ' s F to take i n t o account s t i l l another f a c t o r , the volume of r e a r i n g space. They proposed the use of the Pond Loading Index (PLI) method. The PLI method hinges on an index, Wi, which i s expressed i n S.I. u n i t s of kilograms of f i s h per cub i c meter of r e a r i n g space per water turnover per hour per centimeter of body l e n g t h . Values of Wi f o r raceways as a f u n c t i o n of water temperatures and a l t i t u d e s are presented i n 11 K l o n t z e t . a l . (1978). 3. MEASURES OF GROWTH In comparative s t u d i e s , i t appears a p p r o p r i a t e to monitor growth parameters such as feed c o n v e r s i o n r a t i o 'and f i s h c o n d i t i o n f a c t o r i n a d d i t i o n t o the usual measurements of weight and l e n g t h data. 1. GROWTH RATE By d e f i n i t i o n , growth r a t e i s the change i n body weight with respect to time (dw/dt) and s p e c i f i c growth r a t e i s the change i n body weight per u n i t of body weight with respect to time (dW/Wdt). In most cases, i t s u f f i c e s to present growth data i n terms of the s p e c i f i c growth r a t e , u s u a l l y , p l o t t i n g the percent weight gain a g a i n s t time. For t r o u t , however, H a s k e l l (1959) t h e o r i z e d that under c o n d i t i o n s of constant water temperature and adequate water supply, the ra t e of inc r e a s e i n le n g t h i s constant except i n times of abnormal metabolism as i n di s e a s e , spawning, and other s t r e s s e s . In the l i g h t of these, t r o u t growth w i l l be monitored and compared i n terms of percent weight gain and len g t h g a i n . 2. FEED CONVERSION RATIO Feed c o n v e r s i o n r a t i o i s a measure of feed c o n v e r s i o n e f f i c i e n c y . In other f i e l d s of en g i n e e r i n g , e f f i c i e n c y i s u s u a l l y measured as a percentage. However, i t seems to have become a p r a c t i c e among a q u a c u l t u r i s t s to express t h i s 12 e f f i c i e n c y as the the r a t i o of the kilograms of feeds used to the kilograms of f i s h produced. Thus, the lower the feed c o n v e r s i o n r a t i o , the higher i s the feed c o n v e r s i o n e f f i c i e n c y . Feed c o n v e r s i o n r a t i o s found i n the l i t e r a t u r e range from 1.30 to 4.46 (Brauhn e t . a l . , 1976; . K i n c a i d e t . a l . , 1976; K l o n t z e t . a l . , 1978; Landless, 1979). 3. FISH CONDITION FACTOR H a s k e l l (1959) o r i g i n a t e d the concept of f i s h c o n d i t i o n f a c t o r . I t s t a t e s that the weight and l e n g t h of a f i s h i s r e l a t e d by a constant, C. M a t h e m a t i c a l l y , the r e l a t i o n s h i p i s expressed as W = CL 3 where W = i s the f i s h weight, L = i s the f i s h l e n g t h , and C = i s a constant c a l l e d the c o n d i t i o n f a c t o r . He observed t h a t , although the c o n d i t i o n f a c t o r v a r i e s with environmental c o n d i t i o n s , food s u p p l i e s , and age, i n g e n e r a l , i t averages about the same f o r groups of t r o u t under hatchery c o n d i t i o n s . Reported values of C f o r rainbow t r o u t range from 0.011 to 0.014 when W i s i n u n i t s of grams and L i s i n u n i t s of c e n t i m e t e r s (US F i s h & W i l d l i f e S e r v i c e , USDI, 1977). 13 4. GROWTH PROGRAMMING Growth programming i s the p r e d i c t i o n of growth r a t e given c e r t a i n c o n d i t i o n s of the f a c t o r s a f f e c t i n g growth r a t e . Most of the e a r l i e r mentioned pond l o a d i n g determination methods can be used f o r growth programming. K l o n t z e t . a l . (1978) designed computer programs which b a c k - c a l c u l a t e i n i t i a l l o a d i n g based on a maximum l o a d i n g at the end of a growth p e r i o d as determined by each of these pond l o a d i n g methods. Landless (1979) presented a method by which the number of days needed to in c r e a s e the f i s h weight by a c e r t a i n f a c t o r , e.g., 1.5, can be c a l c u l a t e d . T h i s method l i k e the computer programs prepared by Klon t z e t . a l . (1978) are based on an assumed feed c o n v e r s i o n r a t i o . S t a u f f e r (1973) developed a growth model based on feed r a t i o n , the i n i t i a l weight of f i s h , and water temperature. Using data gathered from h a t c h e r i e s r e a r i n g coho and chinook salmon, he concluded that the s p e c i f i c growth r a t e can be p r e d i c t e d as a sine f u n c t i o n with the above f a c t o r s as the independent v a r i a b l e s . Consequently, he dev i s e d a computer program that p r e d i c t s the growth of salmonids at weekly, semi-monthly or monthly i n t e r v a l s . The program i s a l s o capable of p r e d i c t i n g the feed r a t i o n needed to grow the f i s h to a predetermined s i z e . 1 4 5. TANKS FOR TROUT CULTURE The more popular c u l t u r e tanks f o r t r o u t are the raceways, the c i r c u l a r tanks, and the r e c t a n g u l a r c i r c u l a t i n g ponds (Burrows' ponds). The most recent type i s the v e r t i c a l tank ( s i l o ) . 1. RACEWAY It i s a r e c t a n g u l a r channel where the water i n l e t i s l o c a t e d at one end and the o u t l e t i s at the o p p o s i t e end. The standard raceway i s about 24 m long X 2.4 m wide X 1.2 m high. The bottom slopes toward the o u t l e t at about 0.7%. Water depth i s u s u a l l y 0.9 m. The hatchery troughs are s m a l l - s c a l e raceways. Normal flow r a t e s are from 1 to 4 exchanges per hour. Reported s t o c k i n g d e n s i t i e s range from 16 to 32 kg/m3 and c a r r y i n g c a p a c i t i e s vary from 0.4 to 5.0 kg/l/min. Commercial raceways are u s u a l l y made of concrete while hatchery troughs are made of f i b e r g l a s s . 2. CIRCULAR TANK The diameter ranges from 1.2 m to 12 m. The depth v a r i e s from 0.6 to 1.2 m. Water i s int r o d u c e d i n t o the tank t a n g e n t i a l l y through a nozzle at the s i d e . The nozzle i s i n c l i n e d from 30° to 60° from the h o r i z o n t a l . Chesness e t . a l . (1973) found that maximum a e r a t i o n i s achieved when the nozzle i s i n c l i n e d 30° from the v e r t i c a l and when the j e t entered the water s u r f a c e at one t h i r d of the d i s t a n c e from the center of the tank. The o u t l e t u s u a l l y c o n s i s t s of 2 c o n c e n t r i c 15 v e r t i c a l pipes r i g h t at the middle of the tank. The t a l l e r , outer pipe has s l o t s at the bottom through which the water seeps and flows over the inner standpipe down to the d r a i n . The height of the inner standpipe determines the l e v e l of water in the tank. Small p o r t a b l e tanks are u s u a l l y made of f i b e r g l a s s while bigger tanks are made of c o n c r e t e . Water flow r a t e s are from 0.5 to 1 exchange per hour. Reported s t o c k i n g d e n s i t i e s range from 16 to 120 kg/m3 and c a r r y i n g c a p a c i t i e s range from 1.2 to 2.5 kg/l/min. 3. RECTANGULAR CIRCULATING POND Li k e the raceway, i t i s a r e c t a n g u l a r channel e i t h e r 15.3 or 22 m long, 5.2 m wide, and 1.2 m high. Water depth can be set at e i t h e r 0.76 or 0.90 m. I t has a c e n t r a l w a l l around which the water c i r c u l a t e s and the c i r c u l a t i n g flow p a t t e r n i s enhanced by v e r t i c a l t u r n i n g vanes at the 4 c o r n e r s . Water i s intr o d u c e d through 2 columns of n o z z l e s l o c a t e d near 2 d i a g o n a l c o r n e r s . The water j e t s are d i r e c t e d p a r a l l e l to the long w a l l and d i r e c t l y a g a i n s t the curve of the end w a l l s . The o u t l e t c o n s i s t s of aluminum bottom screens at the s i d e s and opposite ends of the c e n t r a l w a l l . Water flow r a t e i s e q u i v a l e n t to about 1.6 water exchanges per hour. Pond l o a d i n g v a l u e s are from a low of 16 to a high of 32 kg/m3 or from 0.6 to 1.2 kg/l/min. The pond i s made of c o n c r e t e . Standard raceways can be converted i n t o r e c t a n g u l a r c i r c u l a t i n g ponds (Burrows & Chenoweth, 1970). 16 4. VERTICAL TANK E a r l y i n v e s t i g a t i o n s i n the Pennsylvania F i s h Commission were made i n 6.3 l i t e r p l a s t i c j a r s and 208 l i t e r s t e e l drums. The prototype was a f i b e r g l a s s s i l o , 2.3 m i n diameter and 5.0 m in h e i g h t , with a water volume of approximately 20 m3. The maximum s t o c k i n g d e n s i t y ' a t t a i n e d was 136 kg/m3 and the c a r r y i n g c a p a c i t y ranged from 1.6 to 1.8 kg/l/min (Buss e t . a l . , 1968a; 1968b; 1970). In a v e r t i c a l tank, the water i n l e t i s a pipe extending down to a few cen t i m e t e r s from the bottom r i g h t at the center of the tank. The incoming water i s d i r e c t e d a g a i n s t the tank base. The water r i s e s and overflows at the top through a screen i n t o a g u t t e r . Both screen and g u t t e r completely surround the top of the tank. Water supply i s from 4 to 5 exchanges per hour. 6. GROWTH COMPARISON STUDIES Se v e r a l s t u d i e s i n the past have been addressed to the qu e s t i o n of what tank i s most s u i t a b l e to a given set of environmental c o n d i t i o n s . Surber (1936) made the f i r s t e x t e n s i v e report on the use of c i r c u l a r pools f o r the r e a r i n g of t r o u t . He d i s c u s s e d i n depth the s t r u c t u r a l f e a t u r e s of t h i s tank type and enumerated i t s advantages and disadvantages. Johnson and Gastineau (1952) i n search f o r ways by which the weight of the e n t i r e l o t of f i s h i n a t y p i c a l raceway pond c o u l d be a c c u r a t e l y estimated found that a r e p r e s e n t a t i v e sample of chinook .salmon f i n g e r l i n g s reared i n 6-foot diameter c i r c u l a r 17 tanks grew at the same r a t e as the main l o t grew i n the raceways. Samples h e l d i n hatchery troughs d i d not grow as f a s t a f t e r reaching an average weight of 8 grams. Palmer e t . a l . (1952) s i m i l a r l y found that growth r a t e s of chinook salmon f i n g e r l i n g s a t t a i n e d i n c i r c u l a r tanks are comparable to those i n Foster-Lucas ponds. 1 They concluded that c i r c u l a r tanks as small as 3 fe e t i n diameter are s a t i s f a c t o r y f o r use i n the r e a r i n g of a small r e p r e s e n t a t i v e sample of f i s h to estimate the growth rate i n l a r g e F oster-Lucas ponds. These two s t u d i e s were conducted with d i f f e r e n t water volumes and s t o c k i n g d e n s i t i e s between the compared tanks so that the r e s u l t s do not r e f l e c t at a l l the r e l a t i v e performance of the tanks i f and when they are sub j e c t e d to s i m i l a r c o n d i t i o n s . Burrows and Chenoweth (1955) e s t a b l i s h e d a c o r r e l a t i o n of the p h y s i c a l and b i o l o g i c a l c o n d i t i o n s with the h y d r a u l i c c h a r a c t e r i s t i c s i n 3 d i f f e r e n t tank types. They claimed t h a t , on the b a s i s of o v e r a l l e f f i c i e n c y , the c i r c u l a r tank i s b e t t e r than the raceway which i s , i n tu r n , b e t t e r than the Foster-Lucas pond. Comparison was made under both c o n d i t i o n s of optimum water supply and comparable water supply. The 4 measures of e f f i c i e n c y adopted were c a r r y i n g c a p a c i t y , d i s e a s e i n h i b i t i o n , food d i s t r i b u t i o n , and s e l f - c l e a n i n g c h a r a c t e r i s t i c s . A sequel to t h i s r e port was e n t i r e l y devoted to the d e s c r i p t i o n of a new r e a r i n g tank, namely, the r e c t a n g u l a r c i r c u l a t i n g pond, and how A Foster-Lucas pond i s an oval-shaped tank pr o v i d e d with a center p a r t i t i o n w a l l around which the water c i r c u l a t e s . I t was one of the c u l t u r e tanks i n common use up to the 1960's. 18 i t performed i n an e v a l u a t i o n s i m i l a r to that of the 1955 study (Burrows & Chenoweth, 1970). With the i n c l u s i o n of a f i f t h c r i t e r i o n of e f f i c i e n c y which i s that of v i a b i l i t y or s u r v i v a l r a t e of the:smolts a f t e r r e l e a s e , the i n v e s t i g a t o r s r a t e d t h i s new tank s u p e r i o r over a l l the o t h e r s . A summary of the r e s u l t s i s found in Table I. The h y d r a u l i c p o r t i o n of these s t u d i e s were conducted on model and prototype tanks without f i s h . Table I - Comparative e f f i c i e n c y r a t i n g s of four pond types. Pond > Raceway C i r c u l a r F o s t e r - Burrows' Lucas C r i t e r i a : C a r r y i n g C a p a c i t y Optimum WS 2 3 4 1 Comparable WS 3 2 4 1 Disease I n h i b i t i o n Optimum WS 2 3 4 1 Comparable WS 3 2 4 1 Food D i s t r i b u t i o n 3 1 2 1 S e l f - c l e a n i n g 3 2 4 1 V i a b i l i t y 4 2 3 1 O v e r a l l E f f i c i e n c y : Optimum WS 2.8 2.2 3.4 1.0 Comparable WS 3.2 1.8 3.4 1.0 Notes: a. WS = water supply. b. Low number i n d i c a t e s h i g h e f f i c i e n c y . c. P a t t e r n e d a f t e r Burrows and Chenoweth (1955). Buss e t . a l . (1968a; 1968b; 1970) showed that p r o d u c t i o n i n v e r t i c a l tanks i s more than those of any other known r e a r i n g tank on a per u n i t area b a s i s . S t a r t i n g with experiments on 6.3 l i t e r p l a s t i c j a r s , they proceeded to demonstrate the f e a s i b i l i t y of r e a r i n g t r o u t f i n g e r l i n g s at high s t o c k i n g d e n s i t i e s i n 208 l i t e r steel'drums and a 20 m3 f i b e r g l a s s s i l o . 19 Westers and P r a t t (1977) e s t a b l i s h e d design c r i t e r i a f o r h a t c h e r i e s based on a c o r r e l a t i o n of water q u a l i t y c h a r a c t e r i s t i c s with data on f i s h metabolism. They expounded the advantages of r e a r i n g tanks that approximate the i d e a l p l u g -flow. The c o n c l u s i o n was that raceways are p r e f e r r a b l e to the c i r c u l a t i n g types. 7. HYDRAULIC CHARACTERISTICS OF CULTURE TANKS The c i r c u l a r tank and the Burrows' pond approximate a mixed flow v e s s e l . A mixed flow v e s s e l i s a flow-through tank i n which an incoming s l u g of water i s i n s t a n t a n e o u s l y mixed with the o r i g i n a l water i n the tank r e s u l t i n g i n a homogeneous f l u i d . At any i n s t a n t , the q u a l i t y of the outgoing water i s more or l e s s s i m i l a r to the q u a l i t y of the water r e t a i n e d i n the tank. The raceway t y p i f i e s a plug flow v e s s e l i n which a s l u g of water in t r o d u c e d i n t o the tank w i l l a l s o e x i t as a s l u g . I d e a l l y , no mixing occurs w i t h i n the tank. Not much i s known about the flow p a t t e r n s i n the v e r t i c a l u n i t s although v i s u a l o b s e r v a t i o n s of dye i n d i c a t e d uniform mixing i n s i d e the tank (Buss e t . a l . , 1970). Tracer experimentation i s v a l u a b l e i n e v a l u a t i n g the h y d r a u l i c c h a r a c t e r i s t i c s of chemical r e a c t o r tanks. I t has been used to determine the flow p a t t e r n s i n f i s h c u l t u r e tanks (Burrows & Chenoweth, 1955; P i e d r a h i t a , 1980). I t i n v o l v e s the i n j e c t i o n of dye i n t o the incoming water and monitoring the r a t e at which the dye leaves the tank. The v a r i o u s age d i s t r i b u t i o n curves of a flow-through tank 20 are determined by t r a c e r e x p e r i m e n t a t i o n . These d i s t r i b u t i o n curves are, namely, the E-, F-, and I- cur v e s . The E-curve i s known as the e x i t age d i s t r i b u t i o n f u n c t i o n of the f l u i d elements l e a v i n g the tank. The F-curve i s the cumulative e x i t age d i s t r i b u t i o n f u n c t i o n . The I-curve i s c a l l e d the i n t e r n a l age d i s t r i b u t i o n of the f l u i d elements i n the tank (Wen & Fan, 1975). A c t u a l l y , the E value s are obtained by d i v i d i n g the raw c o n c e n t r a t i o n values by the area under the t i m e - c o n c e n t r a t i o n curve, thus, the E curve and the t i m e - c o n c e n t r a t i o n curve are somewhat s i m i l a r except that the area under E-curve i s equal to u n i t y . Mathematically, the F-curve i s the i n t e g r a l of the E-curve, i . e . , F ( t ) = ,/*E(t)dt, and the I-curve i s the complement of the F-curve, i . e . , I ( t ) = 1 - F ( t ) . From the age d i s t r i b u t i o n curves, the h y d r a u l i c c h a r a c t e r i s t i c s of tanks can be q u a n t i t a t e d i n terms of the mean re s i d e n c e time, the probable flowing-through time, dead volume, v a r i a n c e , and the time of the i n i t i a l appearance of dye at the o u t l e t . Comparison of tanks, h y d r a u l i c a l l y , i s done by e v a l u a t i n g and comparing these parameters. The mean reside n c e time i s n u m e r i c a l l y equal to the time to the ce n t e r of g r a v i t y of the E-curve. I t i s a l t e r n a t e l y r e f e r r e d to as the c e n t r o i d , the e f f e c t i v e d e t e n t i o n time, and the f i r s t moment of the curve. T h e o r e t i c a l l y , i t i s equal to the volume d i v i d e d by the flow r a t e . I t s a c t u a l value i s determined by the e x p r e s s i o n ( L e v e n s p i e l , 1979): 21 E [ t ( i ) + t ( i + i ) ] [ c ( i ) + c ( i + D ] T = 2 z [ c ( i ) + c ( i + l ) ] where t i s the time at which the dye sample was taken with r e f e r e n c e to the time of the i n j e c t i o n , and c i s the c o n c e n t r a t i o n of the dye i n the sample. The probable flowing-through time i s n u m e r i c a l l y equal to the time to the center of the area of the E-curve.' I t denotes the time at which h a l f of the dye p a r t i c l e s have passed through the tank. I t i s equated to the time at which F ( t ) = 0.5. The dead volume r e f e r s to the r e l a t i v e l y stagnant f l u i d i n the tank that exchanges m a t e r i a l very slowly with the flowing stream. In the a n a l y s i s , any dye m a t e r i a l remaining i n the tank a f t e r 20 minutes was t r e a t e d as completely stagnant. The dead volume was determined by the approximate e x p r e s s i o n ( L e v e n s p i e l , 1962): Vd = V(1 - R) where Vd i s the approximate dead volume, V i s the t o t a l volume of the tank, and R i s the r a t i o of the observed to the t h e o r e t i c a l mean residence time. The v a r i a n c e i s a c t u a l l y the spread of the E-curve and i t i s an i n d i c a t o r of the mixing i n s i d e the tank. I t i s equal to the second moment of the curve and i t i s determined by the ex p r e s s i o n ( L e v e n s p i e l , 1979): 22 E [ t ( i ) + t ( i + l ) ] 2 [ c ( i ) + c ( i + D ] Var = - T 2 4 E [ c ( i ) + c ( i + 1) ] The time of the i n i t i a l appearance of the dye at the o u t l e t i s an approximate measure of the d i s p e r s i o n i n the tank. The h y d r a u l i c c h a r a c t e r i s t i c s of a tank are governed p r i m a r i l y by the tank shape, volume, and flow rate (Camp, 1945; Chow, 1959) although they can be a f f e c t e d by s t i r r i n g (Chen & Zahradnik, 1967). 8. MODEL THEORY By using the b a s i c p r i n c i p l e s of s i m i l i t u d e , the c o n d i t i o n s in a h y d r a u l i c model can be made to simulate the c o n d i t i o n s i n the prototype i n a known manner. In a system where the flow i s p r i m a r i l y dependent upon i n e r t i a l and g r a v i t a t i o n a l f o r c e s , the model should be designed in accordance with Froude's law which r e q u i r e s that the Froude number i n the model should be equal to the Froude number of the prototype (Webber, 1965). The f i n d i n g s of Burrows and Chenoweth (1955) i n d i c a t e d that small s c a l e models designed i n accordance with Froude's law can p r e d i c t the flow p a t t e r n s i n l a r g e s c a l e r e a r i n g tanks. The Froude number (Fr) i s a dimensionless r a t i o of the i n e r t i a l f o r c e s to the g r a v i t a t i o n a l f o r c e . I t i s c a l c u l a t e d as f o l l o w s . F r 2 = V 2/gL 23 •where V = v e l o c i t y i n length/time u n i t s , g = a c c e l e r a t i o n due to g r a v i t y i n l e n g t h / t i m e 2 u n i t s , and L = i s a c h a r a c t e r i s t i c dimension, e.g., h y d r a u l i c r a d i u s , i n l ength u n i t s . With a n a t u r a l s c a l e f a c t o r of A, the r e l a t e d s c a l e f a c t o r s a r e : Length i n prototype A X (l e n g t h i n model) Area i n prototype A 2 X (area i n model) Volume i n prototype A 3 X (volume i n model) Flow rate i n prototype A 2 ' 5 X (flow r a t e i n model) V e l o c i t y i n prototype A 0 ' 5 X ( v e l o c i t y i n model). 24 I I I . THEORY FORMULATION Th e o r i e s are u s u a l l y developed through the process of l o g i c a l r easoning. The development of the theory underlying' t h i s study was no ex c e p t i o n . B u i l d i n g i t i n v o l v e d : -a. a review of p r o p o s i t i o n s known to be t r u e , b. an assembly of assumptions, and c. a set of i n f e r e n c e s . 1. PROPOSITIONS • The h y d r a u l i c c h a r a c t e r i s t i c s of a tank depend on i t s geometric shape and c o n f i g u r a t i o n among other things(Camp, 1945; Chow, 1959). • The h y d r a u l i c c h a r a c t e r i s t i c s of a tank can be determined by the impulse-response method of t r a c e r experimentation (Levenspiel,1962; Wen & Fan, 1975). • The c o n d i t i o n s i n a h y d r a u l i c model designed i n conformity with the a p p r o p r i a t e p r i n c i p l e s of s i m i l i t u d e are s i m i l a r to those i n the prototype (Webber, 1965). • The p h y s i c a l and b i o l o g i c a l c o n d i t i o n s in a f i s h c u l t u r e tank are c l o s e l y c o r r e l a t e d with the tank h y d r a u l i c c h a r a c t e r i s t i c s (Burrows & Chenoweth, 1955). • Increased s t i r r i n g of water i n a flow-through tank r e s u l t s in a broadening of i t s reside n c e time d i s t r i b u t i o n curve; i n c r e a s i n g the flow r a t e narrows the curve (Chen & Zahradnik, 1967). 25 2. ASSUMPTIONS • The flow p a t t e r n s i n f i s h c u l t u r e tanks are p r i n c i p a l l y governed by i n e r t i a l and g r a v i t a t i o n a l f o r c e s , thus, m o d e l l i n g of the same should be i n conformity with the Froude's Law. • P h y s i c a l and b i o l o g i c a l c o n d i t i o n s i n the tank a f f e c t the growth rate of f i s h to a measurable degree. • F i s h biomass i n the tank d i s p l a c e s water with the e f f e c t of reducing the mean reside n c e time. • F i s h swimming a c t i v i t y i n the tank i s e q u i v a l e n t to s t i r r i n g the water, thus, i t a f f e c t s the h y d r a u l i c c h a r a c t e r i s t i c s of the tanks. 3. INFERENCES • F i s h grown i n models of d i f f e r e n t tanks p o s s e s s i n g d i f f e r e n t h y d r a u l i c c h a r a c t e r i s t i c s w i l l e x h i b i t d i f f e r e n t growth r a t e s . • Growth r a t e i s c o r r e l a t e d to the h y d r a u l i c p r o p e r t i e s of the c u l t u r e tank. • F i s h presence a f f e c t s the h y d r a u l i c c h a r a c t e r i s t i c s of f i s h c u l t u r e tanks. 26 IV. MATERIALS AND METHODS Two separate studies are required to test the hypothesis that f i s h grown under d i f f e r e n t flow conditions vary in growth rates. F i r s t , i t must be shown by hydraulic experiments that the test tanks have d i f f e r e n t flow patterns and, second, growth rate studies must be conducted in the test tanks under similar, at least, comparable conditions of the factors known to affect the growth of the test f i s h . 1. TEST FISH Of the cultured species of salmonids, the rainbow trout was chosen primarily because i t thrives in fresh water during a l l stages of i t s l i f e . Also, the advanced technology surrounding i t s culture minimized the areas of uncertainty in the design of the experiment. F i n a l l y , the extensive practice of rearing the f i s h almost makes i t a certainty that the findings of these experiments w i l l be tested under actual production situations. Fish for the experiments were bought from the Sun Valley Trout Farm Ltd., a private trout hatchery located in Mission, B r i t i s h Columbia. The finge r l i n g s were about 7 month-old, averaging 9 centimeters in length and 9 grams in weight. Although a l l the f i s h were reared under similar conditions from the time they were hatched, they were actually offsprings from several parent f i s h . As such, their d i f f e r e n t genetic attributes could contribute to any resulting v a r i a t i o n in growth rates. In view of t h i s , the f i s h l o t s were rotated from one tank type to another so that, by the end of the growth 27 experiments, every f i s h l o t has had residence i n a l l types of t e s t tank. 2. FACILITIES C h l o r i n e i s t o x i c to rainbow t r o u t at a t r e s h o l d c o n c e n t r a t i o n l e v e l of 0.020 mg/1 (Larson e t . a l . , 1978). The f a c i l i t i e s f o r the experiments were thus set up at the c o u r t y a r d of the Bio - S c i e n c e B u i l d i n g on campus where d e c h l o r i h a t e d water i s a v a i l a b l e . A schematic diagram of the i n s t a l l a t i o n i s shown in F i g u r e 1. 1. TEST TANKS Three types of s m a l l - s c a l e c u l t u r e tanks were t e s t e d , namely, the c i r c u l a r tank, the c i r c u l a r c r o s s - s e c t i o n raceway, and the v e r t i c a l tank. The tank drawings are presented i n F i g u r e s 2-4. Two i d e n t i c a l u n i t s of every tank type were used. The dimensions of the t e s t tanks are l i s t e d i n Table I I . The tanks were designed to e q u a l l y h o l d a water volume of 47 l i t e r s . Table II - Dimensions of t e s t tanks. Diameter Length Water X - s e c t i o n (m) (m) Depth Area (m) (m 2) C i r c u l a r tank 0.60 V e r t i c a l tank 0.30 Raceway ( c i r c u l a r 0.20 c r o s s - s e c t ion) 1 .80 0. 1 68 0.700 0. 1 63 0.280 0.067 0.026 The tanks were made out of c l e a r a c r y l i c g l a s s p i p e s . Transparency was d e s i r e d to f a c i l i t a t e v i s u a l o b s e r v a t i o n s of flow p a t t e r n s i n s i d e the tanks d u r i n g the experiments with dye 28 t r a c e r s . In the d u r a t i o n of the growth s t u d i e s , the s i d e s and bottom of the tanks were covered with b l a c k - p a i n t e d plywood to simulate the dark surroundings of p r o d u c t i o n - s c a l e tanks. Stands f o r the tanks were b u i l t with 3.8 cm X 3.8 cm X 0.64 cm (1.5" X 1.5" X 0.25") s t e e l handy ang l e s . The tanks were so supported that the water s u r f a c e e l e v a t i o n f o r a l l tanks were the same. T h i s made p o s s i b l e equal d e l i v e r y of water to a l l tanks from one constant head r e s e r v o i r . 2. CONSTANT HEAD RESERVOIR A s i n g l e u n i t of r e s e r v o i r s u p p l i e d water to a l l the 6 tanks ( F i g u r e 5). T h i s ensured equal q u a n t i t y and s i m i l a r q u a l i t y of the water inputs to the tanks. The r e s e r v o i r d i s c h a r g e d 5 1/min of water to each tank. The r e s e r v o i r was 60 cm X 60 cm X 90 cm hi g h . I t was made of 1.9 cm (3/4") plywood, p a i n t e d white on the o u t s i d e and f i b e r g l a s s e d i n the i n s i d e . The stand f o r the r e s e r v o i r was made of 5 cm X 10 cm (2" X 4") f i r lumber. The r e s e r v o i r was e l e v a t e d such that i t s o r i f i c e s which c o n t r o l l e d the flow of water to the tanks were about. 50 cm above the water s u r f a c e i n the tanks. The water l e v e l i n s i d e the r e s e r v o i r was maintained by a 5 cm (2") diameter PVC standpipe that was connected to the bottom of the r e s e r v o i r . The flow r a t e measurements and e v a l u a t i o n of the di s c h a r g e c o e f f i c i e n t are presented i n Appendix A. F i g u r e 1 - A schematic diagram of the e x p e r i m e n t a l f a c i l i t i e s . 30 F i g u r e 2 - The c i r c u l a r t e s t t a n k . ( D i m e n s i o n s i n c e n t i m e t e r s . ) F i g u r e 3 - The v e r t i c a l t e s t t a n k . ( D i m e n s i o n s i n c e n t i m e t e r s . ) F i g u r e 4 - The c i r c u l a r c r o s s - s e c t i o n raceway t e s t t a n k . ( D i m e n s i o n s i n c e n t i m e t e r s . ) 33 1 1 i 11 — • A — 1 4 A 5 x10 posts 240 storage iWW/(f Willi iSW F i g u r e 5 - The c o n s t a n t h e a d r e s e r v o i r . ( D i m e n s i o n s i n c e n t i m e t e r s . ) 34 3 . WATER QUALITY MEASUREMENTS The water q u a l i t y parameters monitored throughout the growth s t u d i e s were water temperature, d i s s o l v e d oxygen at the r e s e r v o i r , d i s s o l v e d oxygen at the o u t l e t s of the c u l t u r e tanks, pH and ammonia i n the r e s e r v o i r and c u l t u r e tanks. Samples for water q u a l i t y a n a l y s i s were always taken before the f i r s t f e eding of the day. The frequency of water q u a l i t y measurements v a r i e d from phase to phase. 1. WATER TEMPERATURE No attempt was made to c o n t r o l the temperature of the water in the tanks. Temperature measurements were made with mercury thermometers on a d a i l y b a s i s . At days of d i s s o l v e d oxygen measurements, a thermocouple which i s i n c o r p o r a t e d i n the D.O. probe was used to v e r i f y the thermometer readings. 2. DISSOLVED OXYGEN The equipment used was a Model 5 4 , Yellow Springs Instruments Oxygen Meter equipped with a s t i r r e r and probe. Water samples were c o l l e c t e d i n standard D.O. b o t t l e s and were immediately analyzed at the s i t e . The D.O. meter was c a l i b r a t e d before every s e r i e s of measurement i n accordance with the procedures recommended i n the equipment manual. 35 3. p_H A p o r t a b l e Beckman-Chemmate pH meter made p o s s i b l e measurements at the s i t e . The equipment was c a l i b r a t e d with pH standards before every s e r i e s of measurement. 4. AMMONIA-N Samples were c o l l e c t e d i n 20 ml sample b o t t l e s . The samples were preserved by storage i n a 5°C f r e e z e r from the time of c o l l e c t i o n u n t i l they were ana l y z e d . The method of a n a l y s i s was I n d u s t r i a l Method No. 154-71W f o r ammonia using a Technicon Autoanalyzer I I . 5. DATA ANALYSIS F i s h r e a r i n g s i g n i f i c a n t l y a f f e c t s the water q u a l i t y , i . e . , depresses pH and D.O. l e v e l s and i n c r e a s e s ammonia l e v e l s . The magnitude of these e f f e c t s are represented by the d i f f e r e n c e between the readings i n the r e s e r v o i r and those i n the tank o u t l e t s . The measured e f f e c t s were averaged d u r i n g every phase. Using the mean va l u e s , a two-way a n a l y s i s of v a r i a n c e was undertaken to determine i f there was any s i g n i f i c a n t d i f f e r e n c e between tanks and between phases. The s i g n i f i c a n c e of the f l u c t u a t i o n i n water q u a l i t y between the r e s e r v o i r and the c u l t u r e tanks was a l s o determined. P a r e n t h e t i c a l l y , the U.B.C. computing f a c i l i t i e s were used for most of the s t a t i s t i c a l a nalyses of the r e s u l t s . The T r i a n g u l a r Regression Package (Le & T e n i s c i , 1978) and the General Least Squares Method (Gr e i g & B j e r r i n g , 1977) were used 36 for m u l t i p l e l i n e a r r e g r e s s i o n and a n a l y s i s of v a r i a n c e , r e s p e c t i v e l y . M u l t i p l e r e g r e s s i o n equations were t e s t e d f o r p a r a l l e l i s m and c o i n c i d e n c e using the M u l t i p l e Covariance Program (Osborn e t . a l . , 1979) which i s based on the method developed by Koza'k (1 970) . A Model TT-55, Texas Instruments c a l c u l a t o r was used f o r simple c o r r e l a t i o n and r e g r e s s i o n a n a l y s e s . The c a l c u l a t e d c o r r e l a t i o n c o e f f i c i e n t s , r ' s , were compared with s i g n i f i c a n t values using t a b l e s prepared by Kozak (1966). I n v a r i a b l y , s t a t i s t i c a l s i g n i f i c a n c e (a) was set at the 0.05 l e v e l . 4. GROWTH STUDIES Experimental c u l t u r e of rainbow t r o u t was conducted over 4 growing p e r i o d s or phases. Each phase extended f o r 42 days. At the beginning of every p e r i o d , the 6 tanks (2 each of 3 types) were stocked with the same number of f i s h . A l l f i s h l o t s were given the same feed r a t i o n at the same feed i n g frequency on a d a i l y b a s i s . The d a i l y feed r a t i o n was a d j u s t e d to the d e c r e a s i n g water temperature and the i n c r e a s i n g f i s h s i z e as recommended in the f e e d i n g c h a r t s . Water q u a l i t y parameters were monitored i n a l l tanks as o f t e n as i t was deemed necessary. At the end of every phase, random samples of 20 f i s h were taken from each tank. The f i s h were s t a r v e d f o r 24 hours p r i o r to sampling. The f i s h samples were a n a e s t h e s i z e d using 2-phenoxyethanol. The stock s o l u t i o n was 10% 2-phenoxyethanol and 90% d i s t i l l e d water by volume. To every l i t e r of h o l d i n g water, 5 ml of the stock s o l u t i o n was mixed. I n d i v i d u a l l y , the 37 f i s h were weighed using a Type 2204 Sartorius-Werke balance. The f i s h were a l s o measured f o r l e n g t h with the a i d of a smolt board. From the data obtained, the feed conversion r a t i o and the f i s h c o n d i t i o n f a c t o r ( H a s k e l l , 1959) were c a l c u l a t e d . The f i s h l o t s were r e d i s t r i b u t e d to s t a r t the next phase. Lot r e d i s t r i b u t i o n was done i n a manner such that at the end of 3 phases every f i s h l o t has had r e s i d e n c e in a l l the 3 types of t e s t tank. T h i s was deemed necessary i n view of the f i s h being o f f s p r i n g s from s e v e r a l broodstock f i s h . For the f o u r t h phase, the manner of r e d i s t r i b u t i o n was r e v e r s e d to determine i f the sequence of tank types i n which the f i s h were c u l t u r e d had any e f f e c t on the growth r a t e s . Only one brand of f i s h feeds, "New Age", was used throughout the 4 phases. The feeds were manufactured by the Moore-Clark Co., Inc. of LaConner, Washington, U.S.A.. The feed compositions are l i s t e d i n Appendix B. Number 4 crumbles were used f o r the f i r s t 2 months and 0.24 cm (3/32") p e l l e t s were used f o r the remainder of the growth experiments. 1. PHASE I (AUGUST 14 - SEPTEMBER 24, 1981) On August 13, 1981, 1134 f i s h were brought i n from the Sun V a l l e y t r o u t hatchery. The f i s h were t e m p o r a r i l y unloaded to a 1000 l i t e r f i b e r g l a s s h o l d i n g tank l o c a t e d nearby the experimental tanks. The f i s h were randomly netted from the h o l d i n g tank and d i s t r i b u t e d to the 6 t e s t tanks, 189 f i s h to each tank. At the hatchery p r i o r to the t r a n s p o r t , the f i s h were weighed at 50 to a pound or at an average weight of 9.08 38 grams. No attempt was made to measure the f i s h f o r l e n g t h f o r fear of o v e r s t r e s s i n g them. Instead, a c o n d i t i o n f a c t o r of 0.012 was assumed based on the day 17 measurements and the average i n i t i a l l e ngth was c a l c u l a t e d to be 9.11 c e n t i m e t e r s . On day 17, samples were drawn from the tanks and were weighed and measured f o r l e n g t h . The c o n d i t i o n f a c t o r was estimated to be 0.012. The feed c o n v e r s i o n r a t i o up to that date was found to be 1.8. Beginning day 21, the f i s h were fed at 3.0% of the estimated body weight per day. The body weight on the succeeding days were estimated using the c a l c u l a t e d feed c o n v e r s i o n r a t i o of 1.8.1 From day 1 to day 23, the f i s h were fed 3 times d a i l y . T h e r e a f t e r , f e e d i n g was reduced to 2 times d a i l y . Throughout Phase I, the f i s h were fed #4 crumbles. To a v o i d l o s s of feeds through the d r a i n s i n the v e r t i c a l tanks, the feeds were guided down through a 2.5 cm (1") PVC pipe chute. By r a i s i n g or lowering the chute, the feeds were d i s c h a r g e d at v a r i o u s depths in the tank. The chute feeding was maintained u n t i l the feeds were switched to the 0.24 cm (3/32") p e l l e t s . In the raceways, the feeds were sprayed over the 4 tank openings (Figure 4). Feeds were sprayed a l l over the water s u r f a c e area i n the c i r c u l a r tanks. Water temperature was measured d a i l y . D i s s o l v e d oxygen and pH measurements were i r r e g u l a r though frequent. Throughout the phase, 19 measurements of d i s s o l v e d oxygen and 25 measurements 1 Wt. on day (i+1) = Wt. on day i + (feed per f i s h on day i / 1 . 8 ) . 39 of pH were made. Ammonia was measured d a i l y beginning day 8. On September 25, 1981, a f t e r being s t a r v e d f o r 24 hours, 20 samples of f i s h were randomly drawn from each tank. The samples were an a e s t h e s i z e d , weighed and measured f o r l e n g t h . 2. PHASE II (SEPTEMBER 26 - NOVEMBER 6, 1981) Immediately a f t e r the Phase I weighing, 100 randomly picked f i s h from C i r c u l a r Tank #1 were t r a n s f e r r e d to V e r t i c a l Tank #1; 100 from V e r t i c a l Tank #1 to Raceway #1; and 100 from Raceway #1 to C i r c u l a r Tank #1. The same schedule was observed i n the r e d i s t r i b u t i o n of the #2 f i s h l o t s . The r e d u c t i o n of the number of f i s h to 100 was necessary to a v o i d s u b c r i t i c a l l e v e l s of d i s s o l v e d oxygen i n the tanks. The excess f i s h were t r a n s f e r r e d to the nearby h o l d i n g tank. Feed r a t i o n was maintained at 3.0% body weight per day u n t i l day 21. Then, i t was reduced to 2.5% body weight per day due to the lowering water temperature (10.8°C) and the i n c r e a s i n g f i s h s i z e (estimated at 40 g ) . Beginning on day 20, the feed was switched to 0.24 cm p e l l e t s . Feeding was twice a day during the e n t i r e p e r i o d . D i s s o l v e d .oxygen, pH, and ammonia were measured once every three days. Ammonia and pH were measured on the same days. On November 7, 1981, 20 random samples per tank were, as u s u a l , s t a r v e d , a n a e s t h e s i z e d , weighed, and measured f o r l e n g t h . 40 3. PHASE III (NOVEMBER 8 - DECEMBER 19, 1981) R e d i s t r i b u t i o n of the f i s h l o t s among the tanks for t h i s phase was s i m i l a r to that f o r Phase I I . The number of f i s h per tank was maintained at 100. For the f i r s t 21 days, feed r a t i o n was kept at 2.0% body weight per day. T h i s was reduced to 1.5% body weight per day on day 22 when the water temperature has dropped to 8°C and the average weight of the f i s h was estimated at 73 grams. Throughout t h i s p e r i o d , the feeds were 0.24 cm p e l l e t s . Feeding frequency was maintained at two times per day. . As i n Phase I I , d i s s o l v e d oxygen, pH, and ammonia were monitored once every three days. Sampling and weighing were done on December 20,1981. The same procedures were used as i n the pr e v i o u s phases. 4. PHASE IV (DECEMBER 21, 1981 - JANUARY 31, 1982) On December 20, 1981, 50 f i s h were randomly netted from Raceway #1 and were t r a n s f e r r e d to V e r t i c a l Tank #1; 50 from V e r t i c a l Tank #1 to C i r c u l a r Tank #1; and 50 from C i r c u l a r Tank #1 to Raceway #1. The same r e d i s t r i b u t i o n was done f o r the f i s h l o t s i n the #2 u n i t s . T h i s manner of r e d i s t r i b u t i o n i s the reverse of the previous r e d i s t r i b u t i o n s . The r e d u c t i o n i n the f i s h p o p u l a t i o n per tank was necessary to maintain good environmental c o n d i t i o n s f o r the grown-up f i s h . On the f i r s t day, the water temperature was at a low 6°C and the h e a v i e s t f i s h l o t was averaging 80 grams. A c c o r d i n g l y , the d a i l y feed r a t i o n was reduced to 1.0% body weight. By day 41 14, the water temperature has dropped to below 5°C and the estimated f i s h weight was 90 grams so the r a t i o n was f u r t h e r reduced to 0.8% body weight. T h i s r a t i o n was then maintained u n t i l the end of the phase. Feeding was done twice d a i l y with 0.24 cm p e l l e t s f o r the e n t i r e p e r i o d . Water q u a l i t y measurements were done once every s i x days and a l l measurements were done on the same days. 5. DATA ANALYSIS The growth experiments were designed as randomized complete b l o c k s with a f a c t o r i a l treatment combination (Hicks, 1973). A two-way a n a l y s i s of v a r i a n c e was done f o r each of the growth parameters of percent i n c r e a s e i n weight, i n c r e a s e i n l e n g t h , c o n d i t i o n f a c t o r , and feed c o n v e r s i o n r a t i o . M u l t i p l e r e g r e s s i o n analyses were performed to a r r i v e at e x p r e s s i o n s equating weight gain and length gain to feed r a t i o n , water temperature, and f i s h i n i t i a l weight. The m u l t i p l e r e g r e s s i o n equations were compared fo r e q u a l i t y of slopes and l e v e l s using Kozak's technique (1970). 5. HYDRAULIC STUDIES The h y d r a u l i c s t u d i e s c o n s i s t e d mainly of t r a c e r experiments to gather i n f o r m a t i o n about the behavior of the water as i t passed through the c u l t u r e tanks. An attempt was a l s o made to measure p o i n t v e l o c i t i e s i n the tanks. 42 1. VELOCITY MEASUREMENTS V e l o c i t y measurements were made p r i o r to the s t o c k i n g of the tanks. The instrument used was a Type C2, A. Ott c u r r e n t meter. Supplementary data were obtained by o b s e r v i n g the behavior of styrofoam f l o a t s and feed p a r t i c l e s i n s i d e the tanks. Given the equal flow r a t e s and the uniform s i z e of the i n l e t n o z z l e s , the v e l o c i t i e s of the incoming water f o r a l l the tanks were the same. 2. TRACER EXPERIMENTS Flow p a t t e r n s i n the c u l t u r e tanks were determined by the impulse-response method of t r a c e r e xperimentation. A s l u g of t r a c e r was i n t r o d u c e d i n t o the incoming stream of water at a s p e c i f i e d r e f e r e n c e time and the c o n c e n t r a t i o n of the t r a c e r i n the o u t l e t stream was monitored with respect to the r e f e r e n c e time. The t r a c e r used was malachyte green ( C 2 3 H 2 5 C 1 N 2 ) . T h i s dye was chosen because of i t s known b a c t e r i c i d a l p r o p e r t i e s and i t i s commonly used to c o n t r o l f u n g a l d i s e a s e s , e.g., s a p r o l e g n i a (Huet, 1972; L e i t r i t z & Lewis, 1980). A 5 g/1 stock s o l u t i o n of the dye was prepared by d i l u t i n g the malachyte green c r y s t a l s ( z i n c - f r e e ) i n d i s t i l l e d water. The stock s o l u t i o n was immersed in the water r e s e r v o i r o vernight p r i o r to the experiments so i t was of the same temperature as the incoming water at the time of i n j e c t i o n . I n i t i a l experiments i n d i c a t e d t h at a temperature g r a d i e n t between the dye s o l u t i o n and the water i n the tanks 43 c r e a t e s d e n s i t y c u r r e n t s which i n v a l i d a t e r e s u l t s . 1 Using a d i s p o s a b l e s y r i n g e , 10 ml of the dye stock s o l u t i o n was i n j e c t e d i n t o the incoming water. The t r a j e c t o r y of the dye j e t was o r i e n t e d as much as p o s s i b l e with the d i r e c t i o n of the water stream. The d u r a t i o n of the i n j e c t i o n was approximately 10 seconds, l e s s than 2% of the t h e o r e t i c a l mean re s i d e n c e time. For 20 minutes a f t e r the i n j e c t i o n , grab samples of the outgoing water were c o l l e c t e d at the tank o u t l e t s , once every 30 seconds. The t o t a l number of samples taken per dye run was 40. The absorbance of the dye i n the samples was determined using a Model 139, H i t a c h i Perkin-Elmer UV-VIS spectrophotometer. Absorbance was measured at the wavelength of 616.9 nanometers (nm). I t i s at t h i s wavelength that the peak absorbance of malachyte green i s observed (Stecher, 1968). With the a i d of a b s o r b a n c e - c a l i b r a t i o n curves, the absorbance data were converted i n t o dye c o n c e n t r a t i o n s of the samples. The c a l i b r a t i o n curves were e s t a b l i s h e d by measuring the absorbances of samples with known c o n c e n t r a t i o n s , i . e . , 0.0, 0.4, 0.8, 1.2, 1.6, 2.0 mg/1. A c a l i b r a t i o n curve was prepared f o r every s e r i e s of dye runs. A s e r i e s c o n s i s t e d of 5 dye runs in one tank c o r r e s p o n d i n g to 5 d i f f e r e n t s t o c k i n g d e n s i t i e s . The 5 s t o c k i n g l e v e l s were e q u i v a l e n t to 0, 15, 30, 45, and 100 f i s h p o p u l a t i o n s i n the tank. The s e r i e s of dye runs was r e p l i c a t e d in each of the 6 c u l t u r e tanks to complete a b l o c k . Blocks of A d e n s i t y c u r r e n t i s a flow of a f l u i d i n t o a r e l a t i v e l y q u i e t f l u i d having a d i f f e r e n t d e n s i t y (Camp, 1945). 44 dye runs were conducted toward the l a s t days of Phases I, I I , and I I I . A l l i n a l l , there were 3 blocks or 18 s e r i e s f o r a t o t a l of 90 dye runs. 3. DATA ANALYSIS The raw data obtained from the t r a c e r experiments c o n s i s t e d of time-absorbance v a l u e s . These data were analyzed to e s t a b l i s h the p o i n t s of the v a r i o u s age d i s t r i b u t i o n curves of the tanks under the d i f f e r e n t l o a d i n g c o n d i t i o n s . A computer program, " H y d r a u l i c " , was developed to f a c i l i t a t e a n a l y s i s . The program, w r i t t e n i n FORTRAN (Page & Didday, 1976) i s l i s t e d i n Appendix C. " H y d r a u l i c " was a l s o used to evaluate the h y d r a u l i c c h a r a c t e r i s t i c s of the tanks i n terms of mean re s i d e n c e time, probable flowing-through time, dead volume, v a r i a n c e , and the time of the i n i t i a l appearance of the dye at the o u t l e t . The r e g r e s s i o n of the h y d r a u l i c c h a r a c t e r i s t i c s on the number and weight of the f i s h were determined. 45 V. RESULTS AND DISCUSSION 1. WATER QUALITY 1. TEMPERATURE No change in temperature was d e t e c t e d from the constant head r e s e r v o i r to the o u t l e t s of the c u l t u r e tanks. In e f f e c t , a l l the tanks had the same water temperature at a l l times. Although there was c o n s i d e r a b l e f l u c t u a t i o n i n the ambient temperature dur i n g the day, the d a i l y f l u c t u a t i o n s of the temperature of the water i n the tanks were n e g l i g i b l e . T h i s i n d i c a t e d t hat the heat t r a n s f e r from the surroundings to the water or v i c e versa was not l a r g e enough, to cause a p p r e c i a b l e changes in the water temperature. Heat t r a n s f e r c a l c u l a t i o n s (Kuong, 1969; K r e i t h , 1973) c o n f i r m t h i s f i n d i n g . The biggest temperature d i f f e r e n t i a l was measured on September 7, 1981 when the ambient temperature was 26°C and the water temperature was 15.8°C. With these c o n d i t i o n s , i t was c a l c u l a t e d t h a t , at most, the water temperature i n the raceways would be r a i s e d by 0.35°C. Less temperature changes were c a l c u l a t e d f o r the v e r t i c a l tanks and the c i r c u l a r tanks. The water temperature d u r i n g Phase I rose from 10.5°C on day 1 to 17.2°C on day 13 and then p r o g r e s s i v e l y dropped u n t i l i t was 14.0°C on day 42. From Phase I I , through Phase I I I , to Phase IV, the water temperature continued to drop as the season changed from summer through f a l l to winter. The water temperature on the l a s t day of Phase IV (January 31, 1982) was 4.2°C. The lowest temperature recorded was 4°C. T h i s occurred 46 on days 34 and 35 of Phase IV. S t a t i s t i c a l a n a l y s i s showed that there was s i g n i f i c a n t v a r i a t i o n i n the water temperature from phase to phase with Phase I having the highest and Phase IV having the lowest v a l u e . 2. DISSOLVED OXYGEN The d i s s o l v e d oxygen l e v e l s i n the c u l t u r e tanks were s i g n i f i c a n t l y lower than i n the r e s e r v o i r . Obviously, the drop was due to the consumption of oxygen by the f i s h f o r metabolism. D i s s o l v e d oxygen l e v e l s i n the r e s e r v o i r ranged from 7.2 to 12.6 mg/1 with the higher values c o i n c i d i n g with the low water temperatures. The lowest reading was recorded when the water temperature was 16.6°C (August 21, 1981) while the h i g h e s t value was measured at water temperatures of 4.0°C (January 23, 1982) and 4.9°C (January 2, 1982). Oxygen c o n c e n t r a t i o n s in the r e s e r v o i r ranged from 74% to 98% of the s a t u r a t i o n l e v e l s . The low c o n c e n t r a t i o n s occurred i n the e a r l y days of the experiments when the water was s u p p l i e d to the r e s e r v o i r d i r e c t from the p i p e l i n e s . A e r a t i o n i n the r e s e r v o i r was enhanced by s p r i n k l i n g the incoming water, an obvious e f f e c t of the i n c r e a s e d a i r - w a t e r c o n t a c t a rea. The lowest oxygen l e v e l s measured were 4.8 and 4.9 mg/1 i n V e r t i c a l Tank #2 and V e r t i c a l Tank #1, r e s p e c t i v e l y (September 4, 1981). Aside from these i s o l a t e d cases, the oxygen l e v e l s i n the tanks were at a l l times maintained at or above the c r i t i c a l l e v e l of 5 mg/1. Among the c u l t u r e tanks, the v e r t i c a l tanks recorded the 47 b i g g e s t drop i n oxygen. The drop was measured as the d i f f e r e n c e i n the oxygen l e v e l s between the r e s e r v o i r and the tank. The second biggest drop o c c u r r e d i n the raceways and the c i r c u l a r tanks had the l e a s t drop. The v a r i a t i o n of the drop from tank to tank was s t a t i s t i c a l l y s i g n i f i c a n t . Comparison among the phases showed that Phase III had the bi g g e s t drop, second was Phase I I , t h i r d was Phase I, and l a s t , was Phase IV. Again, the d i f f e r e n c e s were s t a t i s t i c a l l y s i g n i f i c a n t . The f a c t o r s known to a f f e c t oxygen consumption are f i s h s i z e , t o t a l f i s h weight, l e v e l of a c t i v i t y , water temperature, and feed r a t i o n . Since water temperature and feed r a t i o n were always the same for a l l tanks, i t remains that the s i g n i f i c a n t v a r i a t i o n from tank to tank was due to the other 3 f a c t o r s . The v e r t i c a l tanks had the biggest drop because they c o n t a i n e d the hi g h e s t mean biomass 1 in any phase notwithstanding the low l e v e l of a c t i v i t y observed i n these tanks. The c i r c u l a r tanks showed l e s s drop than the raceways although they c o n t a i n e d more biomass than the raceways. T h i s i s e x p l a i n e d by the r e a e r a t i o n that was t a k i n g place i n the c i r c u l a r tanks. With the r e a e r a t i o n , the measured drop i n oxygen l e v e l s underestimated the a c t u a l oxygen consumption. Reaeration was evident i n the c i r c u l a r tanks by the v i s i b l e bubble formation in the region where the incoming j e t entered the water s u r f a c e . C o n s i d e r i n g the low v e l o c i t i e s and the lack of a g i t a t i o n i n the water s u r f a c e of the raceways Mean biomass=l/2 X (biomass at day 0 + biomass at day 4 2 ) . 48 and the v e r t i c a l tanks, the e f f e c t s of r e a e r a t i o n i n these tanks must have been i n c o n s e q u e n t i a l (Downing & Tr u e s d a l e , 1955). The i n c r e a s i n g drop from Phase I to Phase III i s e x p l a i n e d by the i n c r e a s i n g t o t a l f i s h weight i n the tanks as w e l l as the i n c r e a s i n g feed r a t i o n s . The low oxygen consumption d u r i n g Phase IV was due to the r e d u c t i o n of the f i s h biomass i n the tanks. I t c o u l d a l s o be due to the low water temperatures and the r e l a t i v e l y bigger s i z e of the i n d i v i d u a l f i s h d u r i n g the p e r i o d . I t i s r e c a l l e d that as the water temperature goes down or as the average weight of i n d i v i d u a l f i s h i n c r e a s e s , the oxygen consumption per u n i t biomass decreases. The D.O. measurements are found i n Tables I I I - V I . 49 Table III - Phase I - Feed, temperature, and d i s s o l v e d oxygen. DAY DATE FEED/ TEMP DISSOLVED OXYGEN NO. TANK (g) (°C) (mg/1) TANK--> G.I 02 V1 V2 R1 R2 RES 1 AUG 1 4 52 10.5 7.8 - 7.8 7.9 8.0 7.8 7.7 10.0 2 1 5 58 12.0 8.1 7' 8.1 8.6 8.7 8.5 8.7 10.2 3 1 6 58 12.0 8.7. 8.1 8.8 9.0 9.3 9.3 10.6 . 4 1 7 58 12.0 8.5 8.3 8.5 8.7 8.9 8.9 10.2 5 18 58 12.0 6 1 9 68 12.5 7 20 83 14.7 8 21 83 16.6 5.4 5.4 5.5 5.8 6.3 6.3 7.2 9 22 96 16.0 6.4 5.8 6.3 5.8 6.8 6.2 8.2 10 23 96 15.0 7.3 6.8 6.8 6.8 7.2 7.2 9.2 1 1 24 96 17.0 6.6 6.2 5.7 5.6 6.4 6.5 8.8 1 2 25 96 16.0 7.1 6.4 6.3 6.1 6.8 7.0 8.9 13 26 96 17.2 6.2 5.8 5.4 5.5 6.0 6.0 8.6 14 27 96 16.0 1 5 28 96 16.0 16 29 96 17.0 6.4 5.9 5.4 5.3 5.7 5.9 8.9 17 30 96 17.0 18 31 96 16.8 5.9 5.6 5.3 5. 1 6.0 5.5 8.8 19 SEP 1 86 16.8 20 2 86 16.0 21 3 89 15.5 6.1 5.9 5.2 5.2 6.1 6.3 8.9 22 4 91 15.5 5.0 5.1 4.9 4.8 5.8 5.8 8.5 23 5 92 15.5 5.8 5.7 6.0 5.9 5.0 5. 1 8.5 24 6 94 16.0 6.2 6.0 6. 1 6.2 5.6 5.5 8.5 25 7 95 15.8 5.8 5.6 6.0 5.6 6.0 5.5 8.4 26 8 97 14.5 27 9 98 14.8 28 1 0 100 15.0 29 1 1 101 15.0 30 1 2 1 03 15.0 31 1 3 105 14.5 32 1 4 107 14.5 5.9 6.0 6.4 5.8 5.7 5.7 8.9 33 1 5 108 14.5 34 1 6 1 1 0 14.2 35 1 7 1 1 2 14.8 5.9 5.4 5.8 5.2 5.3 5.3 8.6 36 18 1 1 4 14.0 37 19 1 1 6 15.0 38 20 1 18 14.5 39 21 1 20 14.5 40 22 1 22 14.0 41 23 124 14.3 42 24 1 26 14.0 Note : For t h i s and succeeding t a b l e s : C1 = C i r c u l a r Tank #1; C2=Circular Tank #2; V 1 = V e r t i c a l Tank #1; V 2 = V e r t i c a l Tank #2; R1=Raceway #1; R2=Raceway #2; and RES=Reservoir. 50 Table IV - Phase II - Feed, temperature, and d i s s o l v e d oxygen. DAY DATE FEED/ TEMP DISSOLVED OXYGEN NO. TANK (g) (°C) (mg/1) TANK — > C1 C2 V1 V2 R1 R2 RES 1 SEP 26 78 14.0 2 27 80 14.0 7.8 7.1 6.5 6.7 6.9 7.2 9.2 3 28 . 81 13.5 4 29 82 13.5 5 30 84 13.0 7.5 6.7 6.2 6.2 6.3 6.5 9.1 6 OCT 1 86 12.8 7 2 87 12.8 8 3 89 12.5 7.5 6.6 6.7 6.2 6.6 6.5 9.4 9 4 91 12.5 1 0 5 93 12.2 1 1 6 95 12.5 7.5 7.0 6.6 6.5 6.3 6.8 9.5 1 2 7 97 12.0 1 3 8 99 11.5 1 4 9 101 11.5 7.3 6.9 6.9 6.5 7.2 7.1 10.0 1 5 10 1 03 11.5 1 6 1 1 105 11.2 1 7 1 2 107 10.8 ,7.2 7.0 6.6 6.3 6.7 7.0 10.1 18 1 3 109 11.0 19 1 4 1 1 1 10.8 20 1 5 1 1 3 11.0 7.9 7.9 6.6 6.6 7.0 7.3 10.0 21 16 1 1 5 10.8 22 17 98 10.8 23 18 100 10.5 7. 1 6.9 6.4 6.4 7.3 7.2 9.9 24 19 101 10.5 25 20 1 03 10.5 26 21 1 05 10.2 7.6 6.9 7.2 6.8 7.0 7.0 9.7 27 22 1 07 10.5 28 23 1 08 10.5 29 24 1 10 10.5 8.2 7.6 6.9 6.7 7.8 8.2 10.3 30 25 1 1 2 10.5 31 26 1 1 4 10.5 32 27 1 1 6 10.5 7.6 7.5 7.4 7.4 7.8 8.4 10.6 33 28 1 18 10.5 34 29 1 20 10.5 35 30 1 22 10.5 8.0 7.9 7.4 7.6 8.6 7.8 10.8 36 31 1 24 10.5 37 NOV 1 1 26 10.2 38 2 1 28 10.2 8.0 8.1 7.7 7.6 8.4 8.4 10.6 39 3 1 30 10.2 40 4 132 10.2 41 5 1 34 10.0 9.1 9.2 8.6 8.8 9.8 9.0 10.9 42 6 1 36 10.0 51 Table V - Phase III - Feed, temperature, and d i s s o l v e d oxygen. DAY DATE FEED/ TEMP DISSOLVED OXYGEN NO. TANK (g) (°C) (mg/1) TANK — > C1 C2 VI V2 RI R2 RES 1 NOV 8 110 1 0.0 9.6 9.6 8.7 9.3 8.6 8.8 11.0 2 9 1 1 2 9.8 3 10 1 1 4 9.8 4 1 1 1 1 5 9.8 8.9 8.8 8.3 8.3 8.4 8.4 10.8 5 1 2 1 1 7 9.8 6 1 3 1 18 9.8 7 1 4 1 20 9.8 8.3 8.3 7.7 7.5 7.9 7.9 10.6 8 1 5 1 22 9.8 9 1 6 1 23 9.8 10 1 7 1 25 9.5 8.9 8.8 8.5 8.0 7.9 7.6 11.1 1 1 18 1 26 9.5 12 19 1 28 9.5 1 3 20 1 30 9.2 8.3 8.2 6.7 7.2 7.7 7.9 11.0 1 4 21 1 32 9.2 1 5 22 1 33 9.2 1 6 23 1 35 9.0 8.9 8.5 7.0 7.5 7.4 7.4 11.2 1 7 24 1 37 9.0 18 25 1 39 8.8 19 26 141 8.5 8.1 8.3 7.6 7.2 6.9 6.7 11.3 20 27 1 43 8.5 21 28 1 44 8.2 22 29 1 1 0 8.0 9.2 9.0 8.0 7.9 8.1 8.0 11.7 23 30 1 1 1 8.0 24 DEC 1 1 1 2 8.0 25 2 1 1 3 7.8 9.3 9.3 8.0 7.7 8.4 8.3 11.8 26 3 1 14 7.5 27 4 1 1 5 7.5 28 5 1 1 6 7.5 9.6 9.3 8.4 8.2 8.8 8.4 11.8 29 6 1 18 7.2 30 7 1 19 7.0 31 8 1 20 7.0 9.3 9.4 8.8 8.5 9. 1 9.2 12.0 32 9 121 7.0 33 1 0 1 22 7.0 34 1 1 1 24 6.5 9.4 9.7 8.6 8.6 8.7 9.0 1 2.3 35 1 2 1 25 6.5 36 1 3 1 26 6.5 37 1 4 1 27 6.5 10.0 9.8 8.8 9.3 9.4 9.6 12.2 38 15 1 29 6.5 39 16 1 30 6.5 40 1 7 131 6.0 9.8 10.2 9.6 9.2 9.6 9.3 12.3 41 18 1 33 6.0 42 19 1 34 6.0 52 Table VI - Phase IV Feed, temperature, and d i s s o l v e d oxygen. DAY DATE FEED/ TEMP NO. TANK (g) (°C) TANK--> 1 DEC 21 40 6.0 2 22 41 6.0 3 23 41 6.0 4 24 41 5.9 5 25 41 ' 5.9 6 26 42 5.9 7 27 42 5.9 8- 28 42 5.8 9 29 43 5.8 10 30 43 5.5 1 1 31 43 5.5 1 2 JAN 1 44 5.2 1 3 2 44 4.9 1 4 3 44 4.8 1 5 4 36 4.6 1 6 5 36 4.5 1 7 6 36 4.2 18 7 36 4.2 1 9 8 36 4.2 20 9 36 4.5 21 10 36 4.5 22 1 1 36 4.5 23 1 2 37 4.5 24 1 3 37 4.5 25 1 4 37 4.4 26 1 5 37 4.4 27 1 6 37 4.3 28 1 7 37 4.3 29 18 38 4.3 30 1 9 38 4.3 31 20 38 4.2 32 21 38 4.1 33 22 38 4.1 34 23 38 4.0 35 24 39 4.0 36 25 39 4. 1 37 26 39 4.2 38 27 39 4.2 39 28 40 4.2 40 29 40 4.2 41 30 41 4.2 42 31 42 4.2 C1 DISSOLVED OXYGEN (mg/1) C2 VI V2 R1 R2 RES 10.4 10.0 9.8 9.5 10.0 10.1 12.1 10.8 10.4 10.2 10.3 10.7 10.8 12.6 10.4 10.2 9.4 9.2 9.6 10.0 11.7 10.6 10.6 9.6 9.4 10.6 11.0 12.4 10.8 10.8 9.7 9.7 11.2 11.3 12.6 10.6 10.7 9.3 9.4 10.8 11.1 12.4 53 3. p_H Throughout the four phases, the pH of the water remained on the a c i d s i d e . Measurements in the r e s e r v o i r ranged from 5.4 to 6.8. The f l u c t u a t i o n s were probably due to the management of the 2 a l t e r n a t i n g d e c h l o r i n a t o r u n i t s through which the water supply passed. The d e c h l o r i n a t o r u n i t i s a c t u a l l y a f i l t e r c o n s i s t i n g of s e v e r a l l a y e r s of sand, d i f f e r e n t - s i z e d g r a v e l , crushed o y s t e r s h e l l s , and carbon ( P i e d r a h i t a , 1980). L i k e the b a c t e r i a l beds r e f e r r e d to by Burrows and Combs (1968), such a f i l t e r c o u l d cause s i g n i f i c a n t changes i n the ammonia, oxygen, carbon d i o x i d e , carbonate and b i c a r b o n a t e contents of the water passi n g through i t . The f i l t e r s were bac k f l u s h e d twice a week. The pH i n the c u l t u r e tanks f l u c t u a t e d with the pH i n the r e s e r v o i r . However, the pH of the water i n the tanks were c o n s i s t e n t l y lower than i n the r e s e r v o i r . Carbon d i o x i d e p r o d u c t i o n by the f i s h had the e f f e c t of d e p r e s s i n g the pH. The pH drop ranged from 0.0 to 0.7. The lowest pH measured i n the tanks was 5.1 while the highest was 6.7. There was no s i g n i f i c a n t d i f f e r e n c e s i n pH among the c u l t u r e tanks. While the observed pH almost always f e l l o u t s i d e the normal range of 6.7 to.8.6 e s t a b l i s h e d by E l l i s e t . a l . (1946), no adverse e f f e c t s e i t h e r on the f i s h h e a l t h or on the growth rate were observed. T h i s i n d i c a t e d that a pH as low as 5.1 i s not, per se, l e t h a l to t r o u t . I t a l s o suggested that the system was devoid of p o l l u t a n t s the t o x i c i t y of which would have been compounded by the low pH v a l u e s . pH i s a f u n c t i o n of carbon d i o x i d e c o n c e n t r a t i o n and 54 a l k a l i n i t y . In t u r n , the r a t e of carbon d i o x i d e p r o d u c t i o n i s p r o p o r t i o n a l to the r a t e of oxygen consumption by the f a c t o r c a l l e d the r e s p i r a t o r y q u o t i e n t ( B r e t t & Groves, 1978). Due to the s i n g l e water source, i t can be assumed that a l k a l i n i t y was the same f o r a l l the tanks. Thus, the drop i n the pH should have been p r o p o r t i o n a l to the measured oxygen consumptions. Roughly, t h i s was found to be true s i n c e the mean pH drop i n the v e r t i c a l tanks (0.277) was gr e a t e r than that i n the raceways (0.258) and that i n the c i r c u l a r tanks (0.250). However, these d i f f e r e n c e s were not s i g n i f i c a n t s t a t i s t i c a l l y . The drop i n pH s i g n i f i c a n t l y i n c r e a s e d from Phase I to Phase IV. Since oxygen consumption was l e a s t d u r i n g Phase IV, other f a c t o r s c o u l d have c o n t r i b u t e d to the l a r g e pH drop d u r i n g that p e r i o d . For example, i t was l i k e l y that the a l k a l i n i t y of the incoming water changed over time due to the o p e r a t i o n of the d e c h l o r i n a t o r f i l t e r s . Another f a c t o r c o u l d have been a l g a l a c t i v i t y i n the tanks. Through the process of p h o t o s y n t h e s i s , algae convert carbon d i o x i d e i n t o oxygen. I t i s r e c a l l e d that beginning i n the f o u r t h week of Phase I, algae grew i n the tanks and remained i n the system in r e l a t i v e abundance u n t i l the end of Phase III at which time the tanks were cl e a n e d . With the winter weather and photoperiod d u r i n g Phase IV, a l g a l presence and p h o t o s y n t h e t i c a c t i v i t y were a p p a r e n t l y minimized. The pH data are presented i n Tables VII-X. 55 Table VII - Phase I - pH. DAY DATE PH NO. TANK--> C1 C2 VI V2 R1 R2 RES 1 AUG 14 6.0 6.0 6.1 6.1 6.2 6.2 6.2 2 1 5 6.1 6.1 6.2 6.2 6.2 6.2 6.3 3 1 6 6.1 6.1 6.3 6.2 6.2 6.2 6.4 4 1 7 6.0 6.0 6.0 6.0 6.0 6.0 6.1 5 18 6.0 6.0 6.0 6.0 6.0 6.1 6.1 6 1 9 6. 1 6.0 6.0 6.0 6.0 6.0 6.1 7 20 6.1 6.1 6.1 6.1 6.0 6.0 6. 1 8 21 6.1 6.1 6.1 6.1 6.1 6.1 6.2 9 22 6.2 6.2 6.1 6.1 6.1 6.1 6.3 10 23 6.1 6.1 6.1 • 6. 1 6. 1 6.1 6.2 1 1 24 6.1 6.1 6.1 6.1 6.1 6.1 6.2 1 2 25 6.0 6.0 6.0 6.0 6.0 6.1 6.2 1 3 26 6. 1 6.1 6.1 6.1 6.1 6.2 6.2 1 4 27 6.2 6.2 6. 1 6.1 6.1 6.1 6.2 1 5 28 1 6 29 17 30 18 31 6.3 6.3 6.2 6.2 6.2 6.3 6.4 19 SEP 1 20 2 21 3 6.1 6. 1 5.9 6.0 6.2 6.2 6.4 22 4 5.6 5.6 5.6 5.6 5.6 5.7 5.7 23 5 6.3 6.3 6.4 6.3 6.4 6.4 6.5 24 6 6.3 6.3 6.3 6.2 6.2 6.2 6.5 25 7 6.5 6.4 6.4 6.3 6.4 6.3 6.5 26 8 27 9 28 1 0 6.2 6.2 6.2 6.2 6.2 6.2 6.3 29 1 1 30 1 2 31 1 3 5.4 5.4 5.4 5.3 5.3 5.3 5.7 32 1 4 33 1 5 34 1 6 6.2 6.2 6.2 6.2 6.0 6. 1 6.4 35 1 7 36 18 37 1 9 38 20 39 21 6.4 6.4 6.4 6.4 6.4 6.4 6.6 40 22 6.4 6.4 6.6 6.7 6.5 6.5 6.7 41 23 42 24 56 Table VIII - Phase II - pH. DAY DATE pH NO. TANK--> C1 C2 V1 V2 R1 R2 RES 1 SEP 26 2 27 3 28 5.8 5.8 5.8 5.8 5.9 5.9 6.1 4 29 5 30 6 OCT 1 6.2 6.2 6.1 6.1 6.2 6.2 6.4 7 2 8 3 9 4 6.3 6.3 6.2 6.3 6.1 6.1 6.5 10 5 1 1 6 12 7 6.0 6.0 6.0 6.1 6.0 6.0 6.3 13 8 14 9 15 10 5.4 5.3 5.5 .. 5.4 5.5 5.5 5.7 16 11 17 12 18 13 6.1 6.1 6.2 6.2 6.2 6.2 6.3 19 14 20 15 21 16 5.6 5.4 5.4 5.3 5.4 5.5 5.6 22 17 23 18 24 19 6.1 6.1 6.1 6.1 6.1 6.1 6.3 25 20 26 21 27 22 6.1 6.1 6.2 6.2 6.0 6.1 6.4 28 23 29 24 30 25 6.2 6.2 6.1 6.1 6.1 6.2 6.6 31 26 32 27 33 28 6.2 6.2 6.2 6.2 6.2 6.2 6.5 34 29 35 30 36 31 5.9 6.0 6.0 5.9 6.0 6.0 6.4 37 NOV 1 38 2 39 3 5.9 6.0 5.9 5.9 6.0 6.0 6.6 40 4 41 5 42 6 5.9 6.0 5.8 5.8 5.9 5.9 6.3 57 DAY DATE NO. TANK--> C1 1 NOV 8 2 9 5.9 3 10 4 1 1 5 1 2 5.3 6 1 3 7 1 4 8 1 5 6.0 9 1 6 10 1 7 1 1 18 5.3 1 2 19 1 3 20 1 4 21 6.1 1 5 22 1 6 23 1 7 24 5.4 1 8 25 19 26 20 27 5.3 21 28 22 29 23 30 5.6 24 DEC 1 25 2 26 •3 6.2 27 4 28 5 29 6 5.3 30 7 31 8 32 9 6.2 33 10 34 1 1 35 1 2 5.4 36 1 3 37 1 4 38 1 5 6.2 39 16 40 1 7 41 18 6.1 42 19 IX - Phase III - pH. pH C2 VI V2 6.0 6.0 5.9 5.4 5.1 5.1 6.0 6.0 6.0 5.3 5.1 5.1 6.1 6.0 6.0 5.4 5.2 5.3 5.3 5.2 5.3 5.6 5.5 5.6 6.2 6.0 6.0 5*3 5*3 5*3 6.2 6.2 6.2 5.4 5.3 5.3 6.2 6.2 6.2 6.2 6.2 6.1 R1 R2 RES 5 . 9 5 . 9 6.5 5.2 5.2 5.5 6.0 6.0 6.4 5.2 5.3 5.5 6.0 6.0 6.5 5.4 5.3 5.6 5.2 5.2 5.4 5.5 5.6 6.1 6.0 6.1 6.4 5.3 5.3 5.5 6.2 6.2 6.4 5.4 5.4 5.6 6.2 6.2 6.5 6.1 6.1 6.4 58 Table X - Phase IV - pH. DAY DATE pH NO. TANK--> Cl C2 V1 V2 R1 R2 RES 1 DEC 21 2 22 3 23 4 24 5 25 6 26 6.2 6.2 6.4 6.3 6.3 6.3 6.7 7 27 8 28 9 29 10 30 1 1 3 1 12 JAN 1 13 2 6.2 6.2 6.1 6.1 6.2 6.2 6.7 14 3 15 4 16 5 17 6 18 7 19 8 20 9 6.3 6.3 6.3 6.3 6.3 6.4 6.8 21 10 22 11 23 12 24 13 25 14 26 15 27 16 6.3 6.3 6.2 6.2 6.3 6.3 6.8 28 17 29 18 30 19 31 20 32 21 33 22 34 23 6.3 6.3 6.2 6.2 6.3 6.3 6.7 35 24 36 25 37 26 38 27 39 28 40 29 41 30 6.1 6.1 6.0 6.1 6.1 6.1 6.6 42 31 59 4. AMMONIA-N F i s h e x c r e t e s ammonia as i t metabolizes p r o t e i n . T h i s metabolic ammonia i s added to the o r i g i n a l ammonia content of the water supply to make up the t o t a l ammonia c o n c e n t r a t i o n i n the tanks. Measurements of t o t a l ammonia i n mg/1 of NH 3 + N H „ + i n d i c a t e d s i g n i f i c a n t l y higher l e v e l s i n the c u l t u r e tanks than in the r e s e r v o i r . Ammonia l e v e l s i n the r e s e r v o i r ranged from 0.02 to 0.41. As i n the case of the water supply pH, the v a r i a t i o n s c o u l d have been brought about by the o p e r a t i o n and maintenance of the f i l t e r s . C o n s i d e r i n g that the water exchange rate was approximately 6.4 per hour and that the water was not r e c i r c u l a t e d , ammonia c o n c e n t r a t i o n s i n the tanks remained at very low l e v e l s . The h i g h e s t l e v e l recorded was 0.73 while the lowest l e v e l was 0.11 mg/1. With these c o n c e n t r a t i o n s coupled with the low pH values, ammonia t o x i c i t y was never a t h r e a t to the f i s h i n the system. Ammonia pr o d u c t i o n i n the tanks were s t a t i s t i c a l l y the same. A review of models p r e d i c t i n g ammonia production i n h a t c h e r i e s (McLean, 1979) i d e n t i f i e s 3 i n f l u e n c i n g f a c t o r s , namely, feed r a t i o n , water temperature, and f i s h weight. Since feed r a t i o n and water temperature were the same f o r a l l tanks, i t appears that the d i f f e r e n c e s i n the t o t a l biomass i n the tanks were not l a r g e enough to r e s u l t in s i g n i f i c a n t l y d i f f e r e n t ammonia p r o d u c t i o n . The a n a l y s i s f u r t h e r showed that ammonia pr o d u c t i o n d u r i n g Phase II and Phase I I I were s i g n i f i c a n t l y g r e a t e r than those of Phases I and IV. T h i s c o u l d have been due to the heavier 60 biomass and the gre a t e r t o t a l feed r a t i o n s during Phases II and I I I . The ammonia-N measurements are presented i n Tables XI-XIV. 61 Table XI - Phase I - Ammonia-N. DAY DATE NO. TANK--> C1 1 AUG 1 4 2 1 5 3 1 6 4 1 7 5 18 6 1 9 7 20 8 21 0.31 9 22 0.22 10 23 0.26 1 1 24 0.30 1 2 25 0.34 1 3 26 0.50 1 4 27 0.42 1 5 28 0.38 16 29 0.39 1 7 30 0.35 18 31 0.47 1 9 SEP 1 0.41 20 2 0.53 21 3 0.38 22 4 0.42 23 5 0.50 24 6 0.46 25 7 0.54 26 8 0.38 27 9 0.33 28 1 0 0.58 29 1 1 0.38 30 1 2 0.64 31 1 3 0.50 32 1 4 0.50 33 1 5 0.34 34 1 6 0.48 35 1 7 0.46 36 1 8 0.46 37 19 0.59 38 20 0.41 39 21 0.43 40 22 0.57 41 23 0.43 42 24 0.52 AMMONIA-(mg/1) C2 V1 V2 0.19 0.20 0.21 0.26 0.29 0.30 0.29 0.29 0.28 0.30 0. 34 0.33 0.33 0.33 0.33 0.44 0.47 0.41 0.41 0.44 0.43 0.41 0.38 0.38 0.36 0.41 0.54 0.43 0.41 0.41 0.38 0.50 0.47 0.41 0.48 0.45 0.59 0.61 0.59 0.33 0.33 0.38 0.33 0.42 0.42 0.54 0.54 0.50 0.42 0.46 0.50 0.54 0.54 0.54 0.33 0.38 0.42 0.25 0.33 0.33 0.50 0.58 0. 58 0.33 0.38 0.42 0.64 0.61 0.66 0.55 0.55 0. 57 0.36 0.39 0.41 0.39 0.36 0.36 0.41 0.36 0.43 0.43 0.43 0.46 0.39 0.39 0.46 0.55 0.52 0. 50 0.32 0.41 0.43 0.46 0.48 0.46 0.52 0.52 0.59 0.50 0.48 0.48 0.48 0.48 0.52 R1 R2 RES 0.20 0.20 0.19 0.24 0.25 0.21 0.29 0.25 0.24 0.30 0.29 0.25 0.32 0.33 0.27 0.41 0.41 0.34 0.41 0.39 0.28 0.34 0.41 0.28 0.41 0.41 0.31 0.39 0.42 0.38 0.47 0.41 0.34 0.45 0.42 0.28 0.56 0.56 0.33 0.33 0.38 0.25 0.50 0.42 0.25 0.46 0.50 0.29 0. 50 0. 50 0.33 0. 58 0.54 0.29 0.58 0.50 0.25 0.33 0.29 0.17 0.54 0.58 0.25 0.38 0.38 0.25 0.64 0.59 0.30 0.68 0.61 0.30 0.46 0.41 0.30 0.32 0.36 0.30 0.43 0.43 0.30 0.43 0.43 0.32 0.42 0.39 0.32 0.36 0.59 0.32 0.41 0.41 0.32 0.46 0.46 0.32 0.50 0.50 0.32 0.43 0.41 0.32 0.52 0.43 0.30 Table XII DAY DATE NO. TANK--> CI 1 SEP 26 2 27 3 28 0.43 4 29 5 30 6 OCT 1 0.33 7 2 8 3 9 4 0.40 10 5 1 1 6 12 7 0.42 13 8 14 9 15 10 0.23 16 11 17 12 18 13 0.40 19 14 20 15 21 16 0.17 22 17 23 18 24 19 0.40 25 20 26 21 27 22 0.64 28 23 29 24 30 25 0.54 31 26 32 27 33 28 0.33 34 29 35 30 36 31 0.29 37 NOV 1 38 2 39 3 0.30 40 4 41 5 42 6 0.61 62 - Phase II - Ammonia AMMONIA-N (mg/1) C2 VI V2 0.39 0.46 0.43 0.27 0.33 0.46 0.40 0.46 0.60 0.35 0.54 0.48 0.31 0.35 0.35 0.37 0.31 0.25 0.19 0.19 0.19 0.69 0.46 .0.42 0.46 0.54 0.48 0.69 0.56 0.60 0.33 0.35 0.38 0.36 0.35 0.33 0.35 0.48 0.44 0.44 0.55 0.49 N. R1 R2 RES 0.39 0.36 0.30 0.23 0.29 0.21 0.40 0.42 0.23 0.73 0.46 0.15 0.31 0.23 0.12 0.35 0.21 0.14 0.26 0.35 0.14 0.50 0.40 0.39 0.58 0.58 0.37 0.56 0.54 0.37 0.42 0.35 0.10 0.28 0.28 0.10 0.36 0.44 0.12 0.61 0.48 0.41 63 Table XIII - Phase III - Ammonia-N. DAY DATE AMMONIA-N NO. (mg/1) TANK--> CI C2 V1 V2 R1 R2 RES 1 NOV 8 2 9 0.25 0.33 0.25 0.26 0.33 0.25 0.17 3 10 4 1 1 5 12 0.35 0.33 0.32 0.38 0.46 0.35 0.16 6 13 7 14 8 15 0.41 0.33 0.32 0.32 0.36 0.39 0.15 9 16 10 17 11 18 0.44 0.36 0.35 0.33 0.35 0.35 0.29 12 19 13 20 14 21 0.35 0.32 0.34 0.32 0.31 0.36 0.15 15 22 16 23 17 24 0.31 0.31 0.31 0.35 0.33 0.33 0.15 18 25 19 26 20 27 0.30 0.33 0.39 0.35 0.33 0.35 0.13 21 28 22 29 23 30 0.28 0.29 0.29 0.30 0.31 0.28 0.19 2 4 DEC 1 25 2 26 3 0.31 0.29 0.33 0.30 0.31 0.39 0.17 27 4 28 5 29 6 0.22 0.20 0.25 0.23 0.34 0.30 0.03 30 7 31 8 32 9 0.25 0.19 0.20 0.22 0.14 0.25 0.03 33 10 34 1 1 35 12 0.20 0.19 0.22 0.22 0.25 0.20 0.05 36 13 37 14 38 15 0.20 0.19 0.19 0.17 0.17 0.25 0.02 39 16 40 17 41 18 0.11 0.17 0.20 0.22 0.14 0.22 0.03 42 19 64 Table XIV - Phase IV - Ammonia-N. DAY DATE AMMONIA-N NO. (mg/1) TANK--> 1 DEC 21 2 22 3 23 4 24 5 25 6 26 7 27 8 28 9 29 10 30 1 1 31 1 2 JAN 1 1 3 2 1 4 3 1 5 4 16 5 1 7 6 18 7 19 8 20 9 21 10 22 1 1 23 1 2 24 1 3 25 1 4 26 1 5 27 1 6 28 1 7 29 18 30 19 31 20 32 21 33 22 34 23 35 24 36 25 37 26 38 27 39 28 40 29 41 30 42 31 CI C2 VI V2 R1 R2 RES 0.20 0.20 0.27 0.32 0.20 0.22 0.17 0.43 0.47 0.53 0.47 0.52 0.65 0.27 0.27 0.20 0.23 0.20 0.18 0.22 0.17 0.30 0.33 0.30 0.33 0.27 0.30 0.15 0.35 0.35 0.23 0.20 0.20 0.20 0.17 0.28 0.27 0.32 0.37 0.23 0.22 0.10 65 2. MORTALITIES In the morning of day 1 of Phase I, some 19 f i s h were found dead i n the f l o o r around the tanks. Apparently, they jumped out of the tanks o v e r n i g h t . A recount i n every tank would have been s t r e s s f u l l to the f i s h so no adjustments were made to even up the number of f i s h i n every tank. To a v o i d f u r t h e r s i m i l a r m o r t a l i t i e s , screen covers were i n s t a l l e d i n a l l the tanks. An i n v e n t o r y by the end of Phase I r e v e a l e d that there were 186 f i s h i n C i r c u l a r Tank #1, 187 i n C i r c u l a r Tank #2, 189 i n V e r t i c a l Tank #1, 187 i n V e r t i c a l Tank #2, 185 i n Raceway #1, and 179 i n Raceway #2. Aside from the day 1 m o r t a l i t i e s , only two. other f i s h d i e d d u r i n g Phase I. One was i n s i d e V e r t i c a l Tank #2 on day 5 (2.80 g) and the other was in C i r c u l a r Tank #2 on day 37 (6.24 g ) . I t i s b e l i e v e d that these f i s h d i e d i n s i d e the tanks because they were too small to compete and s u r v i v e with the o t h e r s . Three m o r t a l i t i e s occurred d u r i n g Phase I I . On day 8, one f i s h each was found dead i n C i r c u l a r Tank #1 and Raceway #1. Another f i s h was found dead i n C i r c u l a r Tank #1 on day 37. These dead f i s h were weighed and replacements were made with more or l e s s s i m i l a r l y s i z e d f i s h taken from the h o l d i n g tank. No m o r t a l i t y occurred d u r i n g Phases III and IV. 66 3. GROWTH STUDIES WEIGHT GAIN The h i g h e s t weight gain measured was i n V e r t i c a l Tank #2 duri n g Phase I I . T h i s was equal to 33.42 g over 42 days. The lowest weight gain was 12.97 g d u r i n g Phase IV i n Raceway #2. The average weight of the h e a v i e s t f i s h l o t at the end of Phase IV was 101.80 g r e p r e s e n t i n g a t o t a l gain of 92.72 g over the e n t i r e d u r a t i o n of the growth s t u d i e s . The mean weight gains are l i s t e d i n Table XV. The a c t u a l weight and l e n g t h measurements are found i n Appendix D. M u l t i p l e r e g r e s s i o n a n a l y s i s gave the f o l l o w i n g weight gain equat i o n s . C i r c u l a r : dW = 85.361 - 0.714Wo + 0.296F - 5.105T (r 2=0.98l) V e r t i c a l : dW = 109.876 - 0.964WO + 0.426F - 6.728T (r 2=0.972) Raceways: dW = 64.310 - O . 6 6 8 W 0 + 0.425F - 3.879T (r 2=0.993) Combined: dW = 100.075 - 0.825WO + 0.242F - 5.606T (r 2=0.704) where dW = weight gain over 42 days (g), F = t o t a l feed r a t i o n / f i s h over 42 days (g), Wo = i n i t i a l weight of f i s h ( g ) , T = average water temperature/phase (°C), and r 2 = c o e f f i c i e n t of d e t e r m i n a t i o n . 67 A l l the independent v a r i a b l e s are s i g n i f i c a n t i n a l l of the above r e g r e s s i o n equations with the exception of the t o t a l feed r a t i o n i n the equation f o r the c i r c u l a r tank. Comparison by the technique developed by Kozak (1970) showed that the r e g r e s s i o n s u r f a c e s f o r the c i r c u l a r and the v e r t i c a l tanks are s t a t i s t i c a l l y s i m i l a r i n slope but s i g n i f i c a n t l y d i f f e r e n t i n l e v e l . The raceway equation i s s i g n i f i c a n t l y d i f f e r e n t from the other two tank equations i n slope (Appendix E.1). The i m p l i c a t i o n i s t h a t , under s i m i l a r r e a r i n g c o n d i t i o n s , d i f f e r e n t weight gain equations apply to d i f f e r e n t c u l t u r e tanks. The c a l c u l a t e d c o e f f i c i e n t s of d e t e r m i n a t i o n suggest that the accuracy of growth d e s c r i p t i o n models i s improved by t a k i n g i n t o account the type of tank used. A n a l y s i s of v a r i a n c e with Duncarf's m u l t i p l e range t e s t on the percent weight gains (dW/Wo) showed t h a t , i n every phase of the experiments, the v e r t i c a l tanks had s i g n i f i c a n t l y bigger gains than the c i r c u l a r tanks which, i n turn, had c o n s i s t e n t l y bigger gains than the raceways (Appendix E.2). The v a r i a t i o n s from tank to tank were s t a t i s t i c a l l y s i g n i f i c a n t . The a n a l y s i s of v a r i a n c e a l s o showed s i g n i f i c a n t d i f f e r e n c e s with respect to phases. The t r e n d was d e c r e a s i n g from Phase I to Phase IV which i s synonymous to a d e c r e a s i n g s p e c i f i c growth rate f o r i n c r e a s i n g f i s h s i z e . The dropping water temperatures must have l i k e w i s e c o n t r i b u t e d to the d e c r e a s i n g growth t r e n d making s i z e and temperature confounded f a c t o r s . F i n a l l y , the a n a l y s i s showed a s i g n i f i c a n t i n t e r a c t i o n 68 between tank and phase. T h i s means that the d i f f e r e n c e s i n percent weight gains between tanks d i d not remain constant over the 4 phases. This i s b e l i e v e d due to the d e c r e a s i n g r a t e at which the s p e c i f i c growth r a t e decreases with age (Medawar, 1945). In the ad u l t stage where the sharp d e c l i n e of the s p e c i f i c growth rate begins to abate, i t i s l o g i c a l to expect that the d i f f e r e n c e s between tanks w i l l be l e s s pronounced. A c c o r d i n g l y , i n Fig u r e 6, i t i s seen that the tendency was f o r the percent weight gain curves to converge beginning from Phase II to Phase IV. The unusual r e s u l t s of Phase I must have been due to the marginal r e a r i n g c o n d i t i o n s during that p e r i o d which r e s u l t e d i n l e s s than normal growth r a t e s . During that p e r i o d , i t was observed that the water temperatures were too high and the oxygen l e v e l s i n the c u l t u r e tanks verged on the c r i t i c a l l e v e l . . A n a l y s i s was made to check whether the weight gain i n a succeeding phase was i n f l u e n c e d by the weight gain i n the preceding phase. The c o e f f i c i e n t of c o r r e l a t i o n was found to be a low -0.59. Thus, i t i s concluded that the time r e q u i r e d f o r readjustment to a new r e a r i n g environment i s too small to i n f l u e n c e the weight gain a f t e r 6 weeks. Since feed r a t i o n and water temperature were the same f o r a l l the tanks, and si n c e the simple c o r r e l a t i o n between dW and Wo was very low (r=0.06), i t f o l l o w s that there are other u n i d e n t i f i e d f a c t o r s which c o n t r i b u t e d to the s i g n i f i c a n t v a r i a t i o n i n percent weight gains among the tanks. The d e r i v e d m u l t i p l e r e g r e s s i o n equations have been able to account f o r the 69 e f f e c t s of these unknown f a c t o r s through t h e i r constant terms. On the b a s i s of the computed normalized c o e f f i c i e n t s (Le & T e n i s c i , 1978), i t was the constant term which c o n s i s t e n t l y made the most s i g n i f i c a n t c o n t r i b u t i o n to the r e g r e s s i o n in each of the r e g r e s s i o n equations. I t i s t h e o r i z e d that the unknown f a c t o r s were r e l a t e d to the h y d r a u l i c c h a r a c t e r i s t i c s of the tanks. Perhaps a dominant u n i d e n t i f i e d f a c t o r was f i s h a c t i v i t y or the energy expenditure f o r swimming. Deeply i n t e r r e l a t e d with t h i s f a c t o r was the water v e l o c i t y i n the tanks. I t was observed that the f i s h i n the v e r t i c a l tanks were the l e a s t a c t i v e . T h i s was d i c t a t e d p r i m a r i l y by the tank c o n f i g u r a t i o n . The n a t u r a l tendency of a f i s h i s to swim h o r i z o n t a l l y and as f a r as h o r i z o n t a l space was concerned, the v e r t i c a l tanks were the most r e s t r i c t e d . Although the f i s h were d i s t r i b u t e d a l l over the water column, there were s e v e r a l f i s h at any p a r t i c u l a r depth at any time so the f i s h were v i r t u a l l y s t a t i o n a r y . Swimming i n the v e r t i c a l d i r e c t i o n was minimal and was observed only during f e e d i n g . O c c a s i o n a l l y , some f i s h swam up to meet the s e t t l i n g feeds and some d i v e d down to c a t c h the feed p a r t i c l e s that reached the bottom. Inherent i n the design of the v e r t i c a l tank i s that the water flows from the bottom to the top of the tank i n an upwelling f a s h i o n . No v e l o c i t y was d e t e c t a b l e with the c u r r e n t meter along the v e r t i c a l d i r e c t i o n so energy to counte r a c t the upward c u r r e n t must have been minimal. In the c i r c u l a r tanks, the f i s h were a l s o evenly d i s t r i b u t e d , both h o r i z o n t a l l y and v e r t i c a l l y , throughout the 70 tank. The f i s h were most of the time s t a t i o n a r y . However, u n l i k e i n the v e r t i c a l tanks, the f i s h were o b v i o u s l y spending r e l a t i v e l y more energy m a i n t a i n i n g t h e i r p o s i t i o n because of the r e l a t i v e l y higher v e l o c i t i e s . The water was made to c i r c u l a t e c o u n t e r c l o c k w i s e and the f i s h swam a g a i n s t the c u r r e n t . The uniform d i s t r i b u t i o n of the f i s h was d i s t u r b e d only everytime the net cover was opened as d u r i n g feeding or water sampling. The f i s h i n the raceways were perhaps the most a c t i v e as f a r as a c t u a l d i s t a n c e t r a v e l l e d per f i s h was concerned. Swimming in both d i r e c t i o n s w i t h i n the middle h a l f of the tank l e n g t h was observed. Some f i s h s t a t i o n e d themselves a t e i t h e r ends of the tank f a c i n g the end w a l l s . Most of the time, the smaller f i s h were found at the o u t l e t end. Another p o s s i b l e f a c t o r was the feed c i r c u l a t i o n i n s i d e the tanks. In the v e r t i c a l tanks, the p e l l e t s sank very slowly to the bottom so that most of the feeds were consumed before they reached the bottom. For those p a r t i c l e s that d i d reach the bottom, most were kept i n a constant up and down motion by the t u r b u l e n c e i n that s e c t i o n of the tank such that the f i s h had no. d i f f i c u l t y f e e d i n g on them. In the c i r c u l a r tanks, the feeds were swept with the c u r r e n t so the f i s h had only to stay i n one p l a c e and wait f o r the feeds to come i t s way. O c c a s i o n a l l y though, some f i s h found i t necessary to go a f t e r feed p a r t i c l e s upstream or downstream. Some f i s h were observed moving from one spot to another d u r i n g f e e d i n g . S t i l l , other f i s h found time to d i v e f o r feeds at the bottom. As the feeds reached bottom, they were swept along by the c u r r e n t toward the center where they 71 continued to r o l l around the d r a i n pipe u n t i l the f i s h consumed them. In both the v e r t i c a l and c i r c u l a r tanks, the continuous movement of the s e t t l e d feeds induced the f i s h to feed on them. T h i s was not the case in the raceways. The feed p e l l e t s s e t t l e d very q u i c k l y t o the bottom and remained m o t i o n l e s s . However, at the opening near the i n l e t end, the turbulence caused by the incoming water imparted motion to the feeds and prevented some of the feeds from immediate s e t t l i n g . For t h i s reason, d u r i n g f e e d i n g , most of the f i s h c o n s t a n t l y moved to and from t h i s spot. For the same reason, most of the r a t i o n were sprayed over t h i s p a r t of the tank. Since a l l the f i s h c o u l d not be accommodated i n t h i s p r e f e r r e d f e e d i n g spot, the other f i s h were f o r c e d to p o s i t i o n themselves at the other feed openings. Some time a f t e r the l a s t spray of feeds though, even the sunken feeds were e v e n t u a l l y consumed. Due to t h i s d i f f e r e n c e s i n feed c i r c u l a t i o n , d i f f e r e n c e s in feed i n g r a t e s among the tanks were noted. In the v e r t i c a l tanks, i t took between 10 to 15 minutes a f t e r the l a s t spray of feeds f o r the f i s h to consume every feed p a r t i c l e . T h i s l a g time was i n c r e a s e d to about 20 minutes i n the c i r c u l a r tanks and to about 30 minutes i n the raceways. Consequently, i t may be reasonably assumed that n u t r i e n t l e a c h i n g was worst in the raceways and l e a s t i n the v e r t i c a l tanks. 72 F i g u r e 6 - P e r c e n t w e i g h t g a i n s (dW/Wo) f o r t h e c u l t u r e t a n k s p l o t t e d a g a i n s t t i m e . 73 Table XV - Average weight and le n g t h g a i n s . I n i t i a l F i n a l Weight I n i t i a l F i n a l Length Weight Weight Gain Length Length Gain (g) (g) (g) (cm) (cm) (cm) Phase I (42 days) Ci r c u l a r Tank #1 9.08 22.72 1 3.64 9. 1 1 1 2.22 3. 1 #2 9.08 22.97 13.89 9. 1 1 12.31 3.2 V e r t i c a l Tank #1 9.08 24.34 15.26 9. 1 1 12.59 3.4 #2 9.08 25.84 16.76 9. 1 1 12.75 3.6 Raceway #1 9.08 22.47 1 3.39 9. 1 1 12.18 3.0 #2 9.08 22.39 13.31 9. 1 1 1 2.24 3.1 Phase II (42 days) C i r c u l a r Tank #1 22 .47 49. 04 26. 57 12. 18 15. 52 3. 3 #2 22 .39 49. 1 0 26. 71 12. 24 15. 55 3. 3 Ve r t ica1 Tank #1 22 .72 55. 59 32. 87 12. 22 15. 99 3. 7 #2 22 .97 56. 39 33. 42 12. 31 16. 31 4. 0 Raceway #1 24 .34 48. 75 24. 41 12. 59 15. 69 3. 1 #2 25 .84 49. 19 23. 35 12. 75 15. 74 2. 9 Phase III (42 days) C i r c u l a r Tank #1 48. 75 73. 48 24. 73 15. 69 18. 1 5 2. 4 #2 49. 19 74. 26 25. 07 15. 74 17. 89 2. 1 Vert i c a l Tank #1 49. 04 79. 1 2 30. 08 15. 52 18. 33 2. 8 #2 49. 1 0 80. 69 31 . 59 15. 55 18. 53 2. 9 Raceway #1 55. 59 73. 37 17. 78 15. 99 18. 04 2. 0 #2 56. 39 74. 95 18. 56 16. 31 18. 1 3 1 . 8Phase IV (42 days) C i r c u l a r Tank #1 79. 1 2 96 .01 16. 89 18. 33 19. 37 1 .0 #2 80. 69 99 .32 18. 63 18. 53 19. 70 1 . 1 V e r t i c a l Tank #1 73. 37 97 .85 24. 48 18. 04 19. 46 1 .4 #2 74. 95 101 .80 26. 85 18. 1 3 19. 94 1 .8 Raceway #1 73. 48 87 .61 14. 1 3 18. 15 19. 03 0 .8 #2 74. 26 87 .23 12. 97 17. 89 19. 03 1 . 1 74 2. LENGTH GAIN The b i g g e s t length gain recorded over 42 days was 4.0 cm while the l e a s t was 0.85 cm. These are e q u i v a l e n t to 2.86 cm/month and 0.61 cm/month, r e s p e c t i v e l y . The b i g g e s t length gain was observed i n V e r t i c a l Tank #2 dur i n g Phase II c o i n c i d i n g with the observed biggest weight g a i n . The l e a s t gain was i n Raceway #1 d u r i n g Phase IV. Length gains under optimum c o n d i t i o n s r e p o r t e d i n the l i t e r a t u r e range from 1.91 cm/month (P i p e r , 1970) to 3.81 cm/month (Klontz e t . a l . , 1978). The l e n g t h gains f o r the d i f f e r e n t tanks are d e s c r i b e d by the f o l l o w i n g m u l t i p l e r e g r e s s i o n equations. C i r c u l a r : dL = 16.616 - 0.826LO + 0.049F - 0.500T (r 2=0.987) V e r t i c a l : dL = 20.836 - 1.043LO + 0.067F - 0.661T (r 2=0.968) Raceways: dL = 16.051 - 0.858LO + 0.067F - 0.475T (r 2=0.999) 6 Combined: dL = 20.078 - 0.969LO + 0.050F - 0.607T (r 2=0.9l9) where dL = l e n g t h gain over 42 days (cm), F = t o t a l feed r a t i o n / f i s h over 42 days (g), Lo = i n i t i a l l e ngth of f i s h (cm), T = average water temperature/phase (°C), and r 2 = c o e f f i c i e n t of d e t e r m i n a t i o n . A l l the independent v a r i a b l e s are s i g n i f i c a n t in the raceway and combined equations. In the c i r c u l a r tank equation, the 75 temperature was not s i g n i f i c a n t while only the feed was s i g n i f i c a n t a t the 0.05 l e v e l i n the v e r t i c a l tank r e g r e s s i o n . The r e g r e s s i o n s u r f a c e s f o r the three tanks are p a r a l l e l but are d i f f e r e n t from each other in l e v e l (Appendix E.3). Again, the c o e f f i c i e n t of determination f o r the combined equation i s l e s s than those f o r the tanks. Comparison of l e n g t h gains among tanks gave the same r e s u l t s as the comparison by percent weight gai n , i . e . , h i g h e s t in v e r t i c a l tanks, second in c i r c u l a r tanks, and lowest in the raceways (Appendix E.4). With respect to the growing p e r i o d s , Phase II showed the l a r g e s t gain i n length but t h i s gain was s t a t i s t i c a l l y s i m i l a r to the gain d u r i n g Phase I. Phases II and I gains were s i g n i f i c a n t l y bigger than the Phase I I I gain which, i n t u r n , was s i g n i f i c a n t l y bigger than the Phase IV g a i n . The minimal l e n g t h gains d u r i n g Phases I I I and IV were o b v i o u s l y due to the low water temperatures during these p e r i o d s . The Phase I le n g t h gain being l e s s than the Phase II gain was another i n d i c a t i o n t h a t the Phase I c o n d i t i o n s were not conducive f o r t r o u t growth. There was no i n t e r a c t i o n between tank and phase. T h i s tends to c o n f i r m the theory that the r a t e of i n c r e a s e i n l e n g t h of t r o u t i s constant under c o n d i t i o n s of constant water temperature and adequate food supply ( H a s k e l l , 1959). The c o e f f i c i e n t of c o r r e l a t i o n , r, between succeeding and preceding l e n g t h gains was estimated to be 0.50. The l e n g t h gain data are l i s t e d i n Table XV and these are p l o t t e d i n F i g u r e 7. 76 F i g u r e 7 - Length gains f o r the c u l t u r e tanks p l o t t e d a g a i n s t time. 77 3. FEED CONVERSION RATIO The c a l c u l a t e d feed c o n v e r s i o n r a t i o s d u r i n g these experiments ranged from 1.23 to 2.93 kg of feeds/kg of f i s h (Table XVI). The a n a l y s i s of v a r i a n c e f o r the feed c o n v e r s i o n data showed that the feed c o n v e r s i o n r a t i o s f o r the v e r t i c a l tanks were the lowest. They were s i g n i f i c a n t l y lower than those f o r the c i r c u l a r tanks. The raceways was the l e a s t e f f i c i e n t with the h i g h e s t feed c o n v e r s i o n r a t i o s . Since feed r a t i o n was maintained at same q u a n t i t i e s f o r a l l the tanks, the comparison of the feed c o n v e r s i o n r a t i o s among tanks gave the same r e s u l t s as the comparison by percent weight gain (Appendix E.5). In g e n e r a l , the tendency was f o r the feed c o n v e r s i o n r a t i o to i n c r e a s e with time i n d i c a t i n g d e c r e a s i n g c o n v e r s i o n e f f i c i e n c y with i n c r e a s i n g f i s h s i z e ( F igure 8 ) . K l o n t z e t . a l . (1978) made a s i m i l a r o b s e r v a t i o n i n t h e i r r e p o r t . An e x c e p t i o n to t h i s t r e n d o c c u r r e d when the Phase III f i s h gave higher feed c o n v e r s i o n r a t i o values than the Phase IV f i s h . I t i s e x p l a i n e d that the r e d u c t i o n of the feed r a t i o n c a l l e d f o r by the dropping water temperatures and the i n c r e a s i n g f i s h s i z e d u r i n g Phase III was delayed with respect to p u b l i s h e d feeding c h a r t s so, i n e f f e c t , the Phase III f i s h were somewhat ov e r f e d . Secondly, the s t o c k i n g d e n s i t i e s d u r i n g Phase III were the h i g h e s t (higher than p u b l i s h e d values) so the c o n v e r s i o n e f f i c i e n c y c o u l d have been a d v e r s e l y a f f e c t e d d u r i n g t h i s p e r i o d . Brauhn e t . a l . (1976) found feed c o n v e r s i o n r a t i o to be l i n e a r l y dependent upon mean d e n s i t y . 78 Table XVI - Feed conve r s i o n r a t i o s and c o n d i t i o n f a c t o r s . Phase I (42 days) C i r c u l a r Tank #1 #2 V e r t i c a l Tank #1 #2 Raceway #1 #2 I n i t i a l C o n d i t i o n F a c t o r (g/cm 3) 0.0120 1 0.0120 0.0120 0.0120 0.0120 0.0120 F i n a l C o n d i t i o n Factor (g/cm 3) 0, 0, 0, 0, 0, 0, 0125 01 23 01 22 0125 0124 0122 Feed Conversion R a t i o 1 .57 1 .54 1 .38 1 .27 1.61 1 .68 Phase II (42 days) C i r c u l a r Tank #1 #2 V e r t i c a l Tank #1 #2 Raceway #1 #2 0, 0 0 0 0 0 0124 01 22 01 25 01 23 0122 0125 0, 0, 0, 0, 0, 0, 0131 0131 01 36 0130 01 26 0126 1 .67 1 .67 1 .35 1 .33 1 .82 1.91 Phase III (42 days) C i r c u l a r Tank #1 0.0126 0.0123 2. 1 1 #2 0.0126 0.0130 2. 08 V e r t i c a l Tank #1 . 0.0131 0.0128 1 . 73 #2 0.0131 0.0127 1 . 65 Raceway #1 0.0136 0.0125 2. 93 #2 0.0130 0.0126 2. 81 Phase IV (42 days) C i r c u l a r Tank #1 0.01 #2 0.01 V e r t i c a l Tank #1 0.01 #2 0.01 Raceway #1 0.01 #2 0.01 28 0.0132 1.95 27 0.0130 1.77 25 0.0133 1.35 26 0.0128 1.23 23 0.0127 2.33 30 0.0127 2.54 'The i n i t i a l c o n d i t i o n f a c t o r f o r a l l f i s h was based on measurements on day 17 of Phase I. 79 F i g u r e 8 - F e e d c o n v e r s i o n r a t i o s f o r t h e c u l t u r e t a n k s p l o t t e d a g a i n s t t i m e . 80 4. CONDITION FACTOR I n v e s t i g a t i o n s i n the past have l e d to the f i n d i n g that the weight of a s t r a i n of t r o u t i s r e l a t e d to i t s l e n g t h by a constant c a l l e d the s t r a i n ' s c o n d i t i o n f a c t o r . T h i s was not e x a c t l y the case in these experiments. The c a l c u l a t e d c o n d i t i o n f a c t o r s f o r the t e s t f i s h ranged from 0.0120 to 0.0136 with weight and l e n g t h expressed in terms of grams and centimeters r e s p e c t i v e l y (Table XVI). These are w e l l w i t h i n the range of p u b l i s h e d v a l u e s , 0.0110 to 0.0140. However, there were s i g n i f i c a n t v a r i a t i o n s from tank to tank as w e l l as from phase to phase. H a s k e l l (1959) observed that although, in g e n e r a l , the c o n d i t i o n f a c t o r remains constant i n a hatchery, the c o n d i t i o n f a c t o r a c t u a l l y v a r i e s with environmental c o n d i t i o n s , food s u p p l i e s , and age. Apparently, the e f f e c t s of these f a c t o r s have been a p p r e c i a b l e enough to cause s i g n i f i c a n t d i f f e r e n c e s i n the observed c o n d i t i o n f a c t o r s . The s t a t i s t i c a l a n a l y s i s r e v e a l e d higher c o n d i t i o n f a c t o r s f o r the f i s h in the v e r t i c a l tanks and i n the c i r c u l a r tanks than i n the raceways (Appendix E.6). T h i s i m p l i e s t h a t , f o r a given l e n g t h , the f i s h in the raceways were l i g h t e r when compared to the f i s h i n the other 2 types of tanks. The r e s u l t s a l s o i n d i c a t e d that the c o n d i t i o n f a c t o r s i n c r e a s e d with improved environmental c o n d i t i o n s . The observed low D.O. l e v e l s during Phase I and the higher s t o c k i n g d e n s i t i e s of Phase III c o u l d have caused the c o n d i t i o n f a c t o r s of the f i s h d u r i n g these p e r i o d s to be lower than those of Phases II and IV (Figure 9). There was no i n t e r a c t i o n between tank and phase. 81 1 .40 -I F i g u r e 9 - C o n d i t i o n f a c t o r s f o r t h e c u l t u r e t a n k s p l o t t e d a g a i n s t t i m e . 82 5. LOADING DENSITIES The maximum s t o c k i n g d e n s i t y a t t a i n e d was 171.68 kg/m3. Th i s corresponded to a c a r r y i n g c a p a c i t y of 1.61 kg/l/min. P u b l i s h e d s t o c k i n g d e n s i t i e s range from 16 to 139 kg/m3. Pu b l i s h e d c a r r y i n g c a p a c i t i e s range from 0.6 to 5.0 kg/l/min. Rearing of t r o u t at a s t o c k i n g d e n s i t y of 152 kg/m3 and at a c a r r y i n g c a p a c i t y of 2.05 kg/l/min has been accomplished by Zahradnik (1980, pers. comm.). At the s t o c k i n g d e n s i t y of 171.68 kg/m3, the d i s s o l v e d oxygen and ammonia l e v e l s i n the r e a r i n g tanks were a c t u a l l y maintained near optimum l e v e l s . However, the d i s s o l v e d oxygen l e v e l s were marginal at the much lower s t o c k i n g d e n s i t i e s of Phase I. The problem arose from the high water temperatures coupled with the r e l a t i v e l y smaller s i z e of the f i s h during the p e r i o d . T h i s o b s e r v a t i o n r a i s e s doubt on the v a l i d i t y of using an a b s o l u t e value of s t o c k i n g d e n s i t y as a c r i t e r i o n f o r pond l o a d i n g . The same doubt a p p l i e s to c a r r y i n g c a p a c i t y l i m i t s . Such c r i t e r i a need to be supplemented with f i s h s i z e , water temperature, and even percent oxygen s a t u r a t i o n s p e c i f i c a t i o n s . A l t e r n a t i v e pond l o a d i n g c r i t e r i a such as those proposed by Piper (1970; 1972) and Klont z e t . a l . (1978) should t h e r e f o r e be eyed. I t i s r e i t e r a t e d that K l o n t z ' s method takes i n t o account the volume of r e a r i n g space in a d d i t i o n to the f a c t o r s c o n s i d e r e d i n the P i p e r ' s method. By P i p e r ' s method, the c a l c u l a t e d l o a d i n g f a c t o r , F, at the time of the maximum s t o c k i n g d e n s i t y was 87.09 i n g/cm-l/min which i s l e s s than P i p e r ' s t a b u l a t e d F value of 94.44. T h i s 83 meant that the experimental s t o c k i n g d e n s i t y was s t i l l w i t h i n p e r m i s s i b l e l i m i t s . In c o n t r a s t , at the low s t o c k i n g d e n s i t y of 85.27 at Raceway #2 at the end of Phase I, the c a l c u l a t e d F was 65.49 which i s more than the t a b u l a t e d l i m i t of 60.44. 1 Comparison with K l o n t z ' s pond l o a d i n g i n d i c e s can only be made with the raceways because the p u b l i s h e d Wi va l u e s (Klontz e t . a l . , 1978) are a p p l i c a b l e only to raceways. The c a l c u l a t e d Wi at the end of Phase III f o r Raceway #2 was 1.38 i n g/l-cm which i s l e s s than the maximum a l l o w a b l e of 1.58. For the same tank, at the end of Phase I, the c a l c u l a t e d Wi was 1.09 which s l i g h t l y exceeded the a l l o w a b l e l i m i t of 1.01. Even at the maximum s t o c k i n g d e n s i t y of 171.68 kg/m3 i n V e r t i c a l Tank #2, the Wi was c a l c u l a t e d to be 1.45 which i s s t i l l l e s s than the corr e s p o n d i n g l i m i t of 1.58. The c a l c u l a t e d s t o c k i n g d e n s i t i e s and c a r r y i n g c a p a c i t i e s are shown in Table XVII. For the t a b u l a t e d F and Wi va l u e s , s i t e e l e v a t i o n was assumed at 305 m (1000 f t ) . 84 Table XVII - Stocking d e n s i t i e s "and c a r r y i n g c a p a c i t i e s . I n i t i a l F i n a l S t o c king S t o c k i n g Density D e n s i t y (kg/m 3) I n i t i a l F i n a l C a r r y i n g C a r r y i n g C a p a c i t y Capacity (kg/l/min) Phase I (42 days) Ci r c u l a r Tank #1 35.94 89.91 0.34 0.85 #2 36. 1 3 91 .39 0. 34 0.86 V e r t i c a l Tank #1 36.51 97.88 0.34 0.92 #2 36.13 102.81 0.34 0.97 Raceway #1 35.74 88.45 0.34 0.83 #2 34.57 85.27 0.32 0.80 Phase II (42 days) Ci r c u l a r Tank #1 47.81 104.34 0.45 0 .98 #2 47.64 104.47 0.45 0 .98 Vert i c a l Tank #1 48.34 118.28 0.45 1 . 1 1 #2 48.87 119.98 0.46 1 . 1 3 Raceway #1 51 .79 103.72 0.49 0 .97 #2 54.98 104.66 0.52 0 .98 Phase III (42 days) Ci r c u l a r Tank #1 103.72 156.34 0.97 1 .47 #2 104.66 158.00 0.98 1 .49 V e r t i c a l Tank #1 104.34 168.34 0.98 1 .58 #2 104.47 171.68 0.98 1 .61 Raceway #1 1 18.28 156.11 1.11 1 .47 #2 1 19.98 159.47 1.13 1 .50 Phase IV (42 days) C i r c u l a r Tank #1 84. 17 102.14 0.79 0.96 #2 85.84 105.66 0.81 0.99 Vert i c a l Tank #1 78.06 104. 10 0.74 0.98 #2 79.74 108.30 0.75 1 .02 Raceway #1 78. 1 7 93.20 0.74 0.88 #2 79.74 92.80 0.75 0.87 85 4. HYDRAULIC STUDIES 1. VELOCITY MEASUREMENTS The Type C2, A. OTT c u r r e n t meter lacked the necessary s e n s i t i v i t y to draw s a t i s f a c t o r y v e l o c i t y p r o f i l e s f o r the t e s t tanks. N e v e r t h e l e s s , with supplementary data from o b s e r v a t i o n s of dyes and f l o a t s , i t was confirmed t h a t , with equal flow r a t e s , the v e l o c i t i e s i n the c i r c u l a r tanks were, i n g e n e r a l , higher than the v e l o c i t i e s i n the raceways. F u r t h e r , that the v e l o c i t y of the r i s i n g water in the v e r t i c a l tanks was l e s s compared to those found i n the raceways. A l l v e l o c i t y measurements were made i n the absence of f i s h . The standard c o n d i t i o n s were a flow r a t e of 5 1/min and a nozzle opening of 0.55 cm. In the raceways, the water v e l o c i t y was about 10 cm/sec at 0.50 m from the i n l e t and at 0.10 m from the bottom. A backflow c u r r e n t was observed at the water s u r f a c e w i t h i n the f i r s t h a l f of the tank l e n g t h . At a d i s t a n c e of 1.0 m from the i n l e t , the v e l o c i t i e s c o u l d no longer be d e t e c t e d by the c u r r e n t meter. In the c i r c u l a r tanks, s u r f a c e v e l o c i t i e s ranged from 10 to 30 cm/sec. I t was observed that 0.24 cm p e l l e t s with an estimated s c o u r i n g v e l o c i t y of 12 cm/sec were r o l l e d along the bottom. 1 The equipment was t o t a l l y u s e l e s s i n the v e r t i c a l tanks because Scouring v e l o c i t y : Vsc = [(8B)(S1 - S O ) ( g ) ( D ) / f ] 0 ' 5 where B=constant, S 1 = s p e c i f i c g r a v i t y of p e l l e t , S 0 = s p e c i f i c g r a v i t y of water, g = a c c e l e r a t i o n due to g r a v i t y , D=diameter of the p e l l e t , and f=Weisbach-Darcy f r i c t i o n f a c t o r (Camp, 1945). 86 i t f a i l e d to r e g i s t e r any v e l o c i t y r e a d i n g . The 0.24 cm p e l l e t s , however, were observed to be s e t t l i n g at the r a t e of 7-9 cm/sec which i s about equal to t h e i r estimated s e t t l i n g v e l o c i t y . 1 T h i s i m p l i e d n e g l i g i b l e upward water c u r r e n t . 2. TANK CLASSIFICATION The raw data from the t r a c e r experimentation c o n s i s t i n g of measured absorbances with respect to time are presented i n Appendix F. Given the absorbance-concentration r e l a t i o n s h i p s as determined by c a l i b r a t i o n i n the UV-VIS spectrophotometer, the absorbances were converted i n t o c o n c e n t r a t i o n v a l u e s . The c o n c e n t r a t i o n - t i m e data were then processed with the a i d of the ' H y d r a u l i c ' computer program to determine the v a r i o u s age d i s t r i b u t i o n curves of the tanks. The experimental curves f o r zero l o a d i n g along with the i d e a l curves are p l o t t e d i n F i g u r e s 10-12. 1 S e t t l i n g v e l o c i t y : Vse = [(4g)(S1 - S O ) ( D ) / ( 3 C ) ( S O ) ] 0 ' 5 where C=drag c o e f f i c i e n t , and the other v a r i a b l e s are as p r e v i o u s l y d e f i n e d (Camp, 1945). 87 0 5 0 10.0 15.0 20.0 TIME (MIN) F i g u r e 10 - E - c u r v e s w i t h 0 f i s h f o r t h e e x p e r i m e n t a l and i d e a l t a n k s . 88 TIME (MIN) F i g u r e 11 - F -curves w i t h 0 f i s h f o r t h e e x p e r i m e n t a l and i d e a l t a n k s . 89 T I M E ( M I N ) F i g u r e 12 - I - c u r v e s w i t h 0 f i s h f o r t h e e x p e r i m e n t a l and i d e a l t a n k s . 90 The raceway approximated the plug flow type of tank. A comparison of i t s E-curve with that of the i d e a l plug flow tank p o i n t s to two major d i f f e r e n c e s . The mean re s i d e n c e time of the raceway E-curve was l e s s than the 9.4 minutes computed f o r the i d e a l tank. A l s o , i t s v a r i a n c e assumed a value gr e a t e r than zero which i s that of the i d e a l tank. The departure from the i d e a l mean reside n c e time s i g n i f i e d the presence of dead or stagnant volume of water while the non-zero v a r i a n c e i m p l i e d a c e r t a i n degree of mixing w i t h i n the r e a l tank. The c i r c u l a r tank was confirmed to approximate the completely mixed flow type of tank. As in the case of the raceways, i t d e v i a t e d from the i d e a l i n two counts. I t had dead volume and the degree of mixing was l e s s than p e r f e c t . The age d i s t r i b u t i o n curves f o r the v e r t i c a l tank c l o s e l y resembled those of the c i r c u l a r tank. L i k e the c i r c u l a r tank, i t had dead volume and imperfect mixing. I t i s r e c a l l e d that Buss e t . a l . (1970) made the o b s e r v a t i o n that uranine dye was unifo r m l y d i s t r i b u t e d throughout the 20 m3 prototype v e r t i c a l tank without any n o t i c e a b l e dead volume or eddi e s . Oxygen measurements i n the tanks tend to support the above c l a s s i f i c a t i o n . In the c i r c u l a r tanks, the maximum d i f f e r e n c e of oxygen l e v e l s between any two p o i n t s was found to be 0.1 mg/1. There was a drop of about 0.2 mg/1 from the bottom to the top of the v e r t i c a l tanks. In the raceways, a maximum drop of of 1.0 mg/1 was det e c t e d between the i n l e t and the o u t l e t . A l l these measurements were made on. the same day so the e f f e c t s of t o t a l biomass d i f f e r e n c e s were assumed n e g l i g i b l e . 91 3. HYDRAULIC CHARACTERISTICS The h y d r a u l i c c h a r a c t e r i s t i c s , as e v a l u a t e d by the " H y d r a u l i c " program, are summarized in Tables XVIII-XX. They are p l o t t e d a g a i n s t the number of f i s h , i n F i g u r e s 13-17. A n a l y s i s of the data gave the f o l l o w i n g r e s u l t s . 3.1. The raceways had the longest mean reside n c e time and probable flowing-through time, the l e a s t dead volume and v a r i a n c e , and the l a t e s t time of dye i n i t i a l appearance at the o u t l e t . The v e r t i c a l tanks and the c i r c u l a r tanks had s t a t i s t i c a l l y s i m i l a r values f o r a l l the 5 h y d r a u l i c c h a r a c t e r i s t i c s . 3.2. The number of f i s h i n the tanks had s i g n i f i c a n t e f f e c t s on most of the h y d r a u l i c c h a r a c t e r i s t i c s . As the number of f i s h was i n c r e a s e d , the mean residence time was shortened (0.77<r 2<0.97), the dead volume was i n c r e a s e d (0.77<r 2<0.97), 1 the probable flowing-through time was decreased (0.73^r 2<0.99), the time of the i n i t i a l appearance of dye at the o u t l e t was decreased f o r the raceways ( r 2 = 0 . 7 6 ) , 2 and there was no s i g n i f i c a n t e f f e c t on the v a r i a n c e of the curves. 3.3. The average weight of the f i s h s i g n i f i c a n t l y a f f e c t e d the h y d r a u l i c c h a r a c t e r i s t i c s with the exception of the time of the i n i t i a l appearance of dye at the o u t l e t . The e f f e c t s , 1 The dead volume and the mean reside n c e time are i n v e r s e l y c o r r e l a t e d . 2 Mixing was so instantaneous i n both the c i r c u l a r and the v e r t i c a l tanks that the dye was almost always de t e c t e d by the f i r s t sampling. 92 however, were p u z z l i n g . The Phase II f i s h gave the longest mean residence time, the biggest v a r i a n c e , and the l e a s t dead volume. Together with the Phase I f i s h , they showed longer probable flowing-through time than the Phase III f i s h . These e f f e c t s run c o n t r a r y to the e x p e c t a t i o n s that as the biomass i n the tank i s inc r e a s e d , the mean residence time and the probable f l o w i n g -through time are shortened and the dead volume i s i n c r e a s e d as in the case of the number of f i s h . A p o s s i b l e e x p l a n a t i o n i s that the conduct of the experiments was not e n t i r e l y s a t i s f a c t o r y . S p e c i f i c a l l y , d u r i n g the Phase II t r a c e r experiments, the water supply was v i s i b l y t u r b i d and brown with suspended sediments. The heavy r a i n s that caused s e v e r a l l a n d s l i d e s around Vancouver at that time s i m i l a r l y caused runoff laden with sediments to swamp the c i t y water* r e s e r v o i r . These circumstances c a s t doubts on the v a l i d i t y of the Phase II data. The r e s u l t s confirmed the hypothesis that f i s h presence s i g n i f i c a n t l y a f f e c t s the h y d r a u l i c c h a r a c t e r i s t i c s of the c u l t u r e tanks. In a d d i t i o n , they i n d i c a t e d that the f i s h biomass alone c o u l d not adequately e x p l a i n the accompanying changes. For example, assuming that the f i s h had a s p e c i f i c g r a v i t y of 1.0 (McRaren & Jones, 1978), the space occupied by the f i s h i n the tank i n l i t e r s i s equal to the t o t a l weight of the f i s h i n kilograms. I t was found that there was a poor correspondence between the space occupied by the f i s h and the dead volume as determined from the experimental age d i s t r i b u t i o n c urves. I t becomes obvious, t h e r e f o r e , that there i s yet another f a c t o r , a s s o c i a t e d with the f i s h , that was - s i g n i f i c a n t l y 93 i n f l u e n c i n g the h y d r a u l i c c h a r a c t e r i s t i c s of the tanks. T h i s other f a c t o r i s b e l i e v e d to be the l e v e l of a c t i v i t y or the s t a t e of a g i t a t i o n of the f i s h . Chen and Zahradnik (1967) showed that an i n c r e a s e i n the r a t e of s t i r r i n g i n a Votator heat exchanger r e s u l t e d i n the broadening of the residence time d i s t r i b u t i o n curve. The obvious e f f e c t s are i n c r e a s e d v a r i a n c e and e a r l i e r i n i t i a l appearance of dye at the o u t l e t . The e f f e c t s on the mean res i d e n c e time and the dead volume are not so determinate s i n c e they can e i t h e r be i n c r e a s e d or decreased depending on whether or not a c u t o f f p o i n t i s adopted. 1 F i s h d e f l e c t s or r e v e r s e s the d i r e c t i o n of every p a r t i c l e of water that h i t s i t . In the process, i t c o n t r i b u t e s to r e c i r c u l a t i o n . The amount of water that comes i n contact with the f i s h i s presumably p r o p o r t i o n a l to the amount of swimming by the f i s h . Thus, the more i t swims, the more i t c o n t r i b u t e s to r e c i r c u l a t i o n . R e c i r c u l a t i o n has the obvious e f f e c t of i n c r e a s i n g the mean residence time. To summarize, the f i s h by i t s biomass alone has the e f f e c t s of reducing the mean residence time and the probable f l o w i n g -through time, and i n c r e a s i n g the dead volume. On the other hand, as the f i s h goes i n t o motion, the a c t i v i t y r e s u l t s in i n c r e a s i n g the v a r i a n c e and reducing the time of i n i t i a l The c u t o f f p o i n t i s the chosen time l i m i t beyond which a l l the dye remaining i n the tank are c o n s i d e r e d as entrapped i n dead or stagnant regions ( L e v e n s p i e l , 1962). In these experiments,, the c u t o f f p o i n t was 20 minutes a f t e r the dye i n j e c t i o n which was about 2.1 times the t h e o r e t i c a l mean reside n c e time. 94 appearance of dye at the o u t l e t . That same a c t i v i t y can e i t h e r i n c r e a s e or decrease the mean reside n c e time and the probable flowing-through time with opposite e f f e c t on the dead volume. Due to t h i s l a c k of c o n s i s t e n c y i n the i n d i v i d u a l e f f e c t s of biomass and a c t i v i t y , p r e d i c t i o n of the t o t a l e f f e c t of the f i s h on the h y d r a u l i c c h a r a c t e r i s t i c s of the c u l t u r e tanks i s made d i f f i c u l t . 95 Table XVIII - Hy d r a u l i c propert i e s of c i r c u l a r tanks. No. of F i s h — > 0 15 30 45 100 C i r c u l a r Tank #1 Phase I MRT 7.06 6.89 6.99 7.09 • 6.85 PFTT 5.46 5.58 5.62 5.72 5.48 DV 11 .72 1 2.53 12.04 1 1 .55 1 2.74 VAR 26.22 24.03 25.86 26.20 26.50 INIT 0.50 0.50 0.50 0.50 0.50 Phase II MRT 7.93 7.63 7.60 7.63 7.51 PFTT 6.56 6.20 6.22 6.19 6. 1 1 DV 7.37 8.84 8.99 8.87 9.43 VAR - 27.96 29.53 29.25 29.55 29. 17 INIT 0.50 0.50 0.50 0.50 0.50 Phase III MRT 6.93 6.40 6.55 6.65 5.82 PFTT 5.54 5.04 5.21 5.10 4.32 DV 12.34 1 4.99 1 4.24 13.77 1 7.88 VAR 22.99 21 .53 23.50 25.65 20.63 INIT 0.50 0.50 0.50 0.50 0.50 C i r c u l a r Tank • #2 Phase I MRT 7.06 6.79 6.66 6.73 6.57 PFTT 5.63 5.36 5.21 5.39 5.24 DV 1 1 .72 1 3.07 1 3.69 1 3.33 14.16 VAR 24.85 24.80 24.69 24.47 23.71 INIT 0.50 0.50 0.50 0.50 0.50 Phase II MRT 8.39 8.11 7.78 7.94 7.91 PFTT 7.28 6.89 6.42 6.47 6.65 DV 5.06 6.43 8.08 7.30 7.47 VAR 30.42 29.59 29.74 30.92 30. 17 INIT 0.50 0.50 0.50 0.50 0.50 Phase III MRT 6.51 6. 1 9 6.07 6.19 5.48 PFTT 5.16 4.76 4.69 4.81 3.97 DV 14.43 1 6.03 1 6.63 1 6.05 19.61 VAR 21 .95 21 .88 21 .09 22.34 19.72 INIT 0.50 0.50 0.50 0.50 0.50 Symbol Meaning Unit MRT PFTT DV VAR INIT Mean re s i d e n c e time (min) Probable f l o w i n g through time (min) Dead volume of water i n the tank (1) Variance of the TIME-CONC Curve (min 2) I n i t i a l appearance of dye at the o u t l e t (min) 96 Table XIX - H y d r a u l i c p r o p e r t i e s of v e r t i c a l tanks. No. of F i s h — > 0 15 30 45 100 V e r t i c a l Tank #1 Phase I MRT 7.39 7.46 7.07 7.37 7.15 PFTT 6.19 5.90 5.42 5.89 5.85 DV 10.05 9.71 1 1 .66 10.17 1 1 .24 VAR 25.42 27.26 28.79 26.75 24.35 INIT 0.50 0.50 0.50 0.50 0.50 Phase II MRT 7.70 7.24 7.02 7.03 6.77 PFTT 6.20 5.87 5.56 5.59 5.36 DV 8.52 10.78 1 1 .93 11.85 13.17 VAR 26.49 25.32 26.67 23.65 23. 18 INIT 1 .00 0.50 0.50 0.50 0.50 Phase III MRT 6.85 6.25 6.20 6.42 5.84 PFTT 5.68 4.83 4.79 4.98 4.50 DV .. 12.75 15.75 15.99 1 4.88 1 7.78 VAR 19.47 20.46 20.54 21.16 19.78 INIT 1 .00 0.50 0.50 0.50 0.50 V e r t i c a l Tank #2 Phase I MRT 7.99 7.71 7.68 7.65 7.61 PFTT 6.84 6.56 6.21 6.29 6.25 DV 7.07 8.43 8.61 8.76 8.93 VAR 28.40 26.62 28.71 25.49 27.84 INIT 0.50 0.50 . 0.50 0.50 0.50 Phase II MRT 6.89 6.79 6.70 6.51 6.35 PFTT 5.44 5.23 5.20 4.92 4.96 DV 1 2.53 1 3.05 1 3.48 1 4.46 1 5.23 VAR 23. 1 5 24.63 23.35 25.26 21 .48 INIT 1 .00 0.50 0.50 0.50 0.50 Phase I I I MRT 6.19 6.24 6.38 6.26 5.70 PFTT 4.56 4.70 4.84 4.84 4.23 DV 16.05 15.79 15.11 15.71 18.49 VAR 26.01 25. 18 24. 1 3 22.72 20. 1 7 INIT 0.50 0.50 0.50 0.50 0.50 Symbol Meaning Un i t MRT Mean reside n c e time (min) PFTT Probable fl o w i n g through time (min) DV Dead volume of water i n the tank (1) VAR Var iance of the TIME-CONC Curve (min 2) INIT I n i t i a l , appearance of dye at the o u t l e t (min) 97 Table XX - H y d r a u l i c p r o p e r t i e s of raceways. No. of F i s h --> 0 1 5 30 45 100 Raceway #1 Phase I MRT 8.48 8.26 8.34 8.10 7.64 PFTT 7.49 7.37 7.46 7.23 6.83 DV 4.58 5.71 5.28 6.51 8.78 VAR 13.34 1 4.00 1 4.26 1 4.52 12.71 INIT 3.00 1 .50 2.00 1 .50 1 .50 Phase II MRT 9.23 8.74 8.55 8.54 8.45 PFTT 8.19 7.76 7.62 7.50 7.24 DV 0.84 3.28 4.25 4.31 4.76 VAR 18.05 16.45 1 5.94 18.94 19.49 INIT 2.50 2.50 2.00 1 .50 1 .50 Phase I I I MRT 8.39 9.13 8.36 8.10 7.28 PFTT 7.44 8.10 7.37 6.99 6.28 DV 5.05 1 .37 5.22 6.50 10.61 VAR 12.79 19.39 18.15 17.66 15.94 INIT 2.50 2.00 1 .50 1 .50 1 .50 Raceway #2 Phase I MRT 8.46 8.99 8.19 8.42 7.97 PFTT 7.42 8.27 7.39 7.53 7.06 DV 4.68 2.03 6.04 4.92 7.14 VAR 12.16 1 2.48 13.41 1 3.20 1 3.95 INIT 3.50 3.00 2.00 2.00 1 .50 Phase II MRT 9.26 9.25 9.06 8.92 8.64 PFTT 8.17 8.35 8.04 7.94 7.47 DV 0.68 0.75 1 .70 2.42 3.81 VAR 1 6.46 17.12 19.27 18.57 19.55 INIT 2.00 2.00 1 .50 1 .50 1 .50 Phase III MRT 8.88 8.63 8.54 8.30 7. 36 PFTT 7.90 7.62 7.48 7.18 6.38 DV 2.60 3.87 4.31 5.49 10.18 VAR 1 4.08 1 5.95 17.10 18.85 14.70 INIT 2.50 2.00 2.00 1 .50 1 .00 Symbol Mean ing U n i t MRT Mean residence time (min) PFTT Probable flowing through time (min) DV Dead volume of water i n the tank (1) VAR Variance of the TIME-CONC Curve (min 2) INIT I n i t i a l appearance of dye at the o u t l e t (min) 98 9 . 0 -i 6 0 H—•—•—i—•—•—i—•—•—i—•—•—i-1—•—i—'—•—i—•—•—i—• 1 i 0 15 3 0 . 4 5 . 6 0 . 75 . 9 0 . 105 . 120 NUMBER OF F 3 5 H F i g u r e 13 - Mean r e s i d e n c e times f o r tanks and phases p l o t t e d a g a i n s t number of f i s h . 99 F i g u r e 14 - P r o b a b l e f l o w i n g - t h r o u g h t i m e s f o r t a n k s and p h a s e s p l o t t e d a g a i n s t number o f f i s h . 100 Figure 15 - Dead volumes for tanks and phases plotted against number of f i s h . 101 Figure 16 - Variances for tanks and phases plotted against number of f i s h . 102 F i g u r e 17 - I n i t i a l dye appearances f o r t a n k s and phases p l o t t e d a g a i n s t number of f i s h . 103 5 . CORRELATION BETWEEN HYDRAULIC CHARACTERISTICS AND GROWTH RATES The r e s u l t s of t h i s study i n d i c a t e d t h a t , under comparable water supply, growth ra t e s and, consequently, the feed c o n v e r s i o n e f f i c i e n c i e s are maximized under the c o n d i t i o n s of mixed or c i r c u l a t i n g flow. Plug flow c o n d i t i o n s produced s i g n i f i c a n t l y lower growth r a t e s . It appears t h a t , i n the c i r c u l a t i n g tanks, i t takes the f i s h s h o r t e r time to consume the feeds, thereby, minimizing n u t r i e n t l e a c h i n g . In the v e r t i c a l tanks, e s p e c i a l l y , swimming a c t i v i t y i s minimized. F i n a l l y , i n these tanks, there i s intense mixing t a k i n g p l a c e r e s u l t i n g in homogeneous water q u a l i t y c o n d i t i o n s over time and space. Under such c o n d i t i o n s , the f i s h are p r o t e c t e d from sudden changes i n environmental c o n d i t i o n s that c o u l d be brought about by the incoming water. T h i s i s p a r t i c u l a r l y t rue where the q u a l i t y of the incoming water i s h i g h l y v a r i a b l e and c o u l d not be e f f e c t i v e l y c o n t r o l l e d . F i s h i n plug flow tanks bear the disadvantage of having to r e a d j u s t to new water c o n d i t i o n s i n a much sh o r t e r time. The r e s u l t s f u r t h e r i n d i c a t e d that d i f f e r e n c e s in flow p a t t e r n s notwithstanding s i m i l a r i t y of h y d r a u l i c c h a r a c t e r i s t i c s can give r i s e to d i f f e r e n t growth r a t e s as was the case between the c i r c u l a r and the v e r t i c a l tanks. 1 04 VI. CONCLUSIONS 1. Under the c o n d i t i o n s of the experiments, the v e r t i c a l tanks gave higher growth r a t e s and higher feed conversion e f f i c i e n c i e s than the c i r c u l a r tanks which, i n t u r n , gave higher growth r a t e s and feed c o n v e r s i o n e f f i c i e n c i e s than the c i r c u l a r c r o s s - s e c t i o n raceways. For a given l e n g t h , the f i s h i n the v e r t i c a l and c i r c u l a r tanks were heavier than those i n the raceways. 2. The accuracy of a growth d e s c r i p t i o n model i s improved when i t takes i n t o account the type of the c u l t u r e tank used i n a d d i t i o n to the usual f a c t o r s of feed, water temperature, and f i s h i n i t i a l weight. 3. The time r e q u i r e d f o r readjustment to a new r e a r i n g tank type has n e g l i g i b l e e f f e c t on the weight gain of the f i s h a f t e r 6 weeks of r e s i d e n c e i n the new tank type. 4. S t o c k i n g d e n s i t i e s (kg/m 3) and c a r r y i n g c a p a c i t i e s (kg/l/min) are inadequate measures with which to e s t a b l i s h l i m i t s to pond l o a d i n g d e n s i t i e s . Water temperature and f i s h s i z e must be s p e c i f i e d as i n the P i p e r ' s l o a d i n g f a c t o r method (1970; 1972) and K l o n t z ' s pond l o a d i n g index method (1978). 5. The v e r t i c a l tanks, l i k e the c i r c u l a r tank, approximated the mixed flow tank. The c i r c u l a r c r o s s - s e c t i o n raceways were confirmed to approximate the plug flow tank. 6. The h y d r a u l i c c h a r a c t e r i s t i c s of a c u l t u r e tank were s i g n i f i c a n t l y a f f e c t e d by the i n t r o d u c t i o n of f i s h i n t o the tank. The changes were due to the combined e f f e c t s of the f i s h biomass and t h e i r l e v e l of a c t i v i t y . 105 VI I . RECOMMENDATIONS FOR FUTURE WORK 1. The m u l t i p l e r e g r e s s i o n equations ( S e c t i o n s V.3.1 & V.3.2) are only d e s c r i p t i v e . Experiments designed purposely to generate growth p r e d i c t i o n models f o r d i f f e r e n t tank types are recommended. The type of tank can be accounted f o r i n the growth model as a f a c t o r i n such terms as water v e l o c i t y and mean re s i d e n c e time. 2. Scale up s t u d i e s can be undertaken to v e r i f y the f i n d i n g s of t h i s study. In s c a l i n g , a t t e n t i o n should be focused on the water v e l o c i t i e s which might prove to be the l i m i t i n g f a c t o r , p a r t i c u l a r l y , i n the c i r c u l a r tanks. Some s c a l i n g c o n s i d e r a t i o n s are presented i n Appendix G. 3. The d i f f e r e n t c o n d i t i o n f a c t o r s of the f i s h grown i n d i f f e r e n t tanks c o u l d very w e l l mean d i f f e r e n t f a t and p r o t e i n composition. Thus, a proximate a n a l y s i s i s i n ord e r . 4. V i s u a l o b s e r v a t i o n s i n d i c a t e d d i f f e r e n t suspended s o l i d s c o n c e n t r a t i o n s i n the d i f f e r e n t tanks. Suspended s o l i d s c o n s t i t u t e s one of the f a c t o r s that make up the environment of the f i s h . For t h i s reason as w e l l as f o r p o l l u t i o n c o n t r o l purposes, the dynamics of s o l i d s g eneration and removal in the d i f f e r e n t tanks should be i n v e s t i g a t e d . 5. Comparison of the economic e f f i c i e n c y of the d i f f e r e n t tanks should i n c l u d e the amount of time spent f o r tank maintenance, e.g., feeding and tank c l e a n i n g , as t h i s was found to vary from tank to tank. 6. In fu t u r e t r a c e r experimentations, c o l o r l e s s t r a c e r s should be used to a v o i d e x c i t i n g the f i s h u n n e c e s s a r i l y . A l s o , 106 i t i s advisable to mechanize whenever and wherever possible to ensure consistency of methods. F i n a l l y , more e f f e c t i v e control of the quality of the incoming water should be i n s t i t u t e d to prevent sudden fluctuations that could invalidate r e s u l t s . 7. The theory of f i s h 'biomass + a c t i v i t y ' effect on the hydraulic c h a r a c t e r i s t i c s merits further investigations with the ultimate objective of quantitatively breaking down the combined eff e c t into i t s components. 8. Pond loading c r i t e r i a should consider water temperature and f i s h s i z e . Along this l i n e , experiments should be undertaken to establish appropriate values of the Wi index (Klontz, 1978) for c i r c u l a r and v e r t i c a l tanks. Perhaps, standard indices for a l l types of tank could be adopted. 9. F i n a l l y , the f a c i l i t i e s used in this study need the following modifications: a. The size of the slo t s in the outlet pipes of the raceways and the c i r c u l a r tanks should be enlarged to accommodate the feces of the expected maximum size of test f i s h . I n i t i a l l y , the enlarged slo t s may be wrapped with nets to prevent loss of fry or feeds. The nets can be removed as the f i s h grow in s i z e . This eliminates the need for changing outlet pipes. b. A provision to allow t o t a l draining of the raceways should be i n s t a l l e d . This f a c i l i t a t e s f i s h evacuation during transfer or cleaning. 1 07 BIBLIOGRAPHY 1. Brauhn, J.L., R.C. Simon, and W.R. B r i d g e s . 1976. Rainbow t r o u t growth in c i r c u l a r tanks: Consequences of d i f f e r e n t l o a d i n g d e n s i t i e s . U.S. F i s h and W i l d l i f e Serv. Tech. Paper #86. 16p. 2. B r e t t , J.R. 1964. The r e s p i r a t o r y metabolism and swimming performance of young sockeye salmon. J . F i s h . Res. Bd. Canada, 21:1183-1226. 3. B r e t t , J.R. 1965. 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The p e r c e n t u n - i o n i z e d ammonia i n aqeous ammonia s o l u t i o n s a t d i f f e r e n t pH l e v e l s and t e m p e r a t u r e s . J . F i s h . Res . Bd . Canada , 2 9 ( 1 0 ) : 1 5 0 5 -1 507 . 67 . U .S . F i s h and W i l d l i f e S e r v i c e , USDI . 1977. Manua l of f i s h c u l t u r e . A p p e n d i c e s 1 .5-5.0 - E n g l i s h and m e t r i c l e n g t h - w e i g h t r e l a t i o n s h i p s f o r f i s h . 68 . Webber, N.B. 1965. F l u i d mechan i cs f o r c i v i l e n g i n e e r s . E. and F . N . Spon L t d . , London . 6 9 . Wen, C . Y . and L . T . F a n . 1975. Mode l s f o r f l o w sys tems and c h e m i c a l r e a c t o r s . M a r c e l D e k k e r , I n c . , New Y o r k . 593p . 70 . W e s t e r s , H. 1970. C a r r y i n g c a p a c i t y of s a l m o n i d h a t c h e r i e s . P r o g . F i s h - C u l t . , 3 1 ( 1 ) : 4 3 . 7 1 . W e s t e r s , H. and K .M. P r a t t . 1977. R a t i o n a l d e s i g n of h a t c h e r i e s f o r i n t e n s i v e s a l m o n i d c u l t u r e , based on m e t a b o l i c c h a r a c t e r i s t i c s . P r o g . F i s h - C u l t . , 3 9 ( 4 ) : 1 5 7 -1 6 5 . 72 . W i l l o u g h b y , H. 1968. A method 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 of h a t c h e r y t r o u g h s and p o n d s . P r o g . F i s h -C u l t . , 3 0 ( 3 ) : 1 7 3 - 1 7 4 . 7 3 . Z a h r a d n i k , J .W . 1980. P e r s o n a l c o m m u n i c a t i o n . Department of B i o - R e s o u r c e E n g i n e e r i n g , U n i v e r s i t y of B r i t i s h C o l u m b i a , V a n c o u v e r , B . C . , Canada . 1 13 APPENDIX A - FLOW CONTROL AND DISCHARGE MEASUREMENTS 1. F low C o n t r o l When the water head over the r e s e r v o i r o r i f i c e s was 60 cm", the t o t a l head over the water l e v e l i n the t a n k s was 110 cm. T h i s t o t a l h ead , H, gave a f l ow r a t e of 5 l i t e r s per m inu te t o each c u l t u r e t a n k . The r e g r e s s i o n of the f l ow r a t e on the t o t a l head i s d e f i n e d by the e q u a t i o n : Q = 2.58H + 2.21 ( r 2 = 0 .997) where Q i s i n l i t e r s / m i n u t e , and H i s i n m e t e r s . From the o r i f i c e , the water pa s sed t h r o u g h PVC p i p e f i t t i n g s and 1.25 cm (1/2" ) d i a m e t e r PVC p i p e s u n t i l i t e n t e r e d the tank t h r o u g h a 0.55 cm (7/32" ) n o z z l e . The n o z z l e s were made of b r a s s so they were c o a t e d w i t h a n t i - f o u l i n g p a i n t . The d i s c h a r g e , Q, t h r o u g h a submerged o r i f i c e w i t h a r e a , A , i s d e t e r m i n e d by the e q u a t i o n Q = C A ( 2 g H ) 0 , 5 where C i s the c o e f f i c i e n t of d i s c h a r g e , g i s the a c c e l e r a t i o n of g r a v i t y , and H i s the d i f f e r e n c e i n s u r f a c e l e v e l s between the s o u r c e and the r e c e i v i n g water ( K i n g & B r a t e r , 1963 ) . Fo r the comp le t e i n l e t s y s t e m , the o v e r a l l d i s c h a r g e coe f f i c i e n t , C , was found t o be e q u a l t o 0 .75 • F low r a t i n g d a t a : Head i n T o t a l D i s c h a r g e (1/min) RES (m) Head (m) Tank > CI C2 V1 V2 R1 R2 0 .10 0.60 3.80 3.70 3.70 3.80 3.70 3.75 0 .20 0.70 4 .05 4 .05 3.95 4 .00 4 .00 4 .00 0 .30 0 .80 4 .35 4 .30 4 .25 4 .30 4 .30 4 .25 0 .40 0.90 4 .60 4. 55 4 .60 4 .60 4 .55 4 .55 0 .50 1 .00 4.80 4 .80 4 .75 4 .80 4 .75 4 .80 0 .60 1.10 5.05 5.05 5.00 5.05 5.00 5.00 2. D i s c h a r g e Measurements To compare water d i s c h a r g e s f rom tank t o t a n k , measurements were made p r i o r t o the s t o c k i n g and d u r i n g eve ry p h a s e . The d a t a a r e p r e s e n t e d be low . A n a l y s i s of v a r i a n c e showed no s i g n i f i c a n t v a r i a t i o n f rom tank to tank and from phase t o phase . Tank > C1 C2 V1 V2 R1 R2 P r ep 5.05 5.05 5.00 5.05 5.00 5.00 Phase I 5.05 5.00 5.05 5.05 5.10 5.00 Phase II 5.05 5.05 5.05 5.00 5.05 5.05 Phase I I I 5.00 5.05 5.00 5.00 5.00 5.10 Phase IV 5.00 4 .95 5.05 5.05 5.00 5.05 1 1 4 APPENDIX B - COMPOSITION OF NEW AGE FISH FEEDS 1 . Gua ran t eed A n a l y s i s #4 Crumbles 3/32" P e l l e t s Crude p r o t e i n not l e s s than Crude f a t not l e s s than Crude f i b r e not more than M o i s t u r e not more than Ash not more than 39 .00% 5.50% 7.00% 1 0.00% 15.00% 38 .00% 5.50% 7.00% 10.00% 15.00% 2. I n g r e d i e n t s A n i m a l p r o t e i n p r o d u c t s , p l a n t p r o t e i n p r o d u c t s , p r o c e s s e d g r a i n b y - p r o d u c t s , g r a i n p r o d u c t s , f i s h o i l , l i g n i n s u l f o n a t e , s a l t , e t h o x y q u i n " a p r e s e r v a t i v e " , v i t a m i n p remix c o n s i s t i n g o f : V i t a m i n A a c e t a t e , p y r i d o x i n e h y d r o c h l o r i d e ( B6 ) , V i t a m i n B12 supp l emen t , a s c o r b i c a c i d ( C ) , a l p h a t o c o p h e r o l ( E ) , menadione sodium b i s u l f i t e ( K ) , r i b o f l a v i n ( B2 ) , c h o l i n e c h l o r i d e , t h i a m i n e m o n o n i t r a t e , b i o t i n , n i a c i n , c a l c i u m p a n t o t h e n a t e , f o l i c a c i d , m e t h i o n i n e hyd roxy ana logue c a l c i u m , t r a c e s of manganese s u l p h a t e , magnesium s u l p h a t e , i r o n s u l p h a t e , i r o n c a r b o n a t e , i r o n o x i d e , c a l c i u m c a r b o n a t e , copper c a r b o n a t e , z i n c s u l p h a t e , z i n c o x i d e , p o t a s s i u m i o d i d e , sod ium c a r b o n a t e , c o b a l t s u l p h a t e , c o b a l t c a r b o n a t e . . Added m i n e r a l not more than 3 .00% . APPENDIX C - THE "HYDRAULIC COMPUTER PROGRAM 1. L i s t o f t h e Program 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 C C C C C C C C C C C C C C C C C C C C C C c c c c c c This program calculates and prints out the mean residence time and other hydraulic properties of a test tank as well as the points in the E-, F-, and I- curves from time and absorbance Input data. Note: Blank spaces enclosed 1n brackets Indicate Input data are required. Nomenclature: volume/flow rate out let CONC/TOTA sum of E Symbol Meaning T Time TMT Theoretical mean time = REDT Reduced time = T/TMT ABS Absorbance CONC Concentration of dye at E Exit age distribution = F Cumulative exit age distribution IAD Internal age distribution = 1 - F V Volume of water in the tank 0 Water flow rate M1 First moment of the curve (mean residence time) M2 Second moment of the curve (variance) PFTT Probable f1ow1ng-through time INIT Time of Initial appearance of dye at outlet DV Dead volume of water in the tank TOTA Area under the time-concentration curve M Slope of the regression line relating ABS and B Intercept of the regression line relating ABS r2 Coefficient of determination for the ABS-CONC Uni t Minute M1 nute Dimensionless Nanometer mg/1 Dimensionless Dimensionless Dimensionless Li ter 1/min Minute Minute2 Minute M1 nute Liter mg/1 CONC and CONC regress i on 1 ine Data declaration REAL IAD,M1,M2,M,INIT DIMENSION T(41 ) , REDT(41), ABS(41), B= [(include numerical sign)] C0NC(41), E(41), F(41), IAD(41) M= [ r2= [ V= t 0= [ W=0.0 X = 0.0 Y=0.0 Z=0.0 ] ] 40 C Tit le 41 WRITE (6,10) 42 10 FORMAT (' 1',///,9X,'Tab 1e [ ]. Phase [ ] - Residence time distribution and other') 43 WRITE (6,12) 44 12 FORMAT (' ',20X,'related data for [ ]') 45 WRITE (6,14) 46 14 FORMAT ('0',8X. 'TIME',3X, 'REDUCED',1X,'ABSORBANCE',1X,'CONCENTRATION',3X,'E',6X, 'F ' ,6X,'I ' ) 47 WRITE (6,15) 48 15 FORMAT ( ' + ' , 8X , ' ' ,3X, ' ' ,1X, ' ' ,1X, ' ' , 3X , '_' , 6X , '_ ' , 6X ,'_') 49 WRITE (6,16) 50 16 FORMAT (' ',8X,'(mln)',3X,'TIME',6X,'(nm)',7X ,'(mg/1 )') 51 WRITE (6,17) 52 17 FORMAT ('+',16X,' ' , / ) 53 C 54 C Computation for the theoretical mean residence time. 55 TMT=V/0 56 C 57 DO 18 1=1,41 58 READ (5,19) T(I ) ,ABS(I) 59 19 FORMAT [ ] ^ 60 C £ 61 C Computation for reduced time. 62 REDT(I)=T(I)/TMT 63 C 64 C Computation for concentration from absorbance. 65 CONC(I)=(M * ABS(I)) + B 66 IF ((I) .EO. 1) CONC(I)=0.000 67 IF (CONC(I) .LT. 0.000) CONC(I)=0.000 68 IF (ABS(I) .EO. 0.0) CONC(I)=0.000 69 C 70 18 CONTINUE 71 C 72 C 73 DO 20 d=1 .40 74 C 75 C W 1s the sum of the f i rst 40 concentration levels. 76 W=W + CONC(d) 77 C 78 C X 1s the numerator of the equation to find M1. 79 X = X + (T(d) + T(d+D) * (CONC(d) + C0NC(d+O) 80 C 81 C Y Is the summation 1n the denominator of the equation to find Ml & M2. 82 Y=Y + (CONC(d) + C0NC(J+1)) 83 C 84 C Z Is the numerator 1n the equation to find M2. 85 Z = Z + ((T(J) + T(d+1))**2) * (CONC(d) + C0NC(d+1)) 6 C 87 20 CONTINUE 88 C 89 C Computation for the area under the curve using the trapezoidal rule. 90 T0TA=(W + C0NC(41)/2) * 0.5 91 C 92 C 93 DO 22 K=1,41 94 C 95 C Computation for E. 96 E(K)=C0NC(K)/T0TA 97 C 98 C Computation for F. 99 F(K)=F(K-1) + (E(K) * 0.5) 100 IF ((K-1) .EQ. 0) F(K)=0.000 101 C 102 C Computation for IAD. 103 IAD(K)=1.00 - F(K) 104 C 105 C 106 C Tabulation 107 C H 108 WRITE (6,24) T(K), REDT(K), ABS(K), CONC(K), E(K), F(K), IAD(K) ,j 109 24 FORMAT (' ' ,8X,F4 . 1 ,4X.F4.2,5X,F5.3,8X.F5.3,5X.F5.3,2X,F5.3,2X,F5.3) 1 10 C 111 22 CONTINUE 112 C 113 C Finding the probable f1ow1ng-through time (PFTT). The PFTT 1s the time 114 C to the center of the area under either the T-E curve or the T-C0NC curve. 115 C Since F 1s the Integral of the T-E curve which has an area equal to 1.0, 116 C then the PFTT Is that time which corresponds to the F value of 0.50. 117 C 118 DO 26 L =1.41 119 IF (F(L) .LT. 0.50) GO TO 26 120 PFTT=T(L-1) + ((T(L)-T(L-1))*(0.50-F(L-1))/(F(L)-F(L-1))) 121 GO TO 28 122 26 CONTINUE 123 28 CONTINUE 124 C 125 C Finding the time of the Init ial appearance of the dye at the outlet (INIT). 126 DO 30 N=1 ,41 127 IF (CONC(N) .EQ. 0.0) GO TO 30 128 INIT=T(N) 129 GO TO 32 130 30 CONTINUE 131 32 CONTINUE 132 C 133 C 134 C 135 136 C 137 C 138 139 C 140 C 141 142 C 143 C 144 C 145 146 34 147 148 36 149 150 38 151 152 40 153 154 42 155 156 44 157 158 46 159 160 48 161 C 162 163 Computation for actual mean residence time. M1=X/(2*Y) Computation for variance. M2=Z/(4*Y) - M1**2 Computation for dead volume using Levenspiel's approximate formula. DV = V * (1 - (M1/TMT)) Listing of hydraulic characteristics, etc. WRITE (6,34) TMT FORMAT ('0',8X,'Theoretical Mean Residence Time WRITE (6.36) M1 FORMAT (' ',8X,'Actual Mean Residence Time WRITE (6,38) PFTT FORMAT (' ',8X,'Probable F1ow1ng-through Time WRITE (6,40) INIT FORMAT (' ' ,8X, ' In i t la l Dye Appearance at Outlet WRITE (6,42) M2 FORMAT (' ',8X,'Var i ance WRITE (6.44) DV FORMAT (' '.8X,'Dead Volume WRITE (6.46) TOTA FORMAT (' ',8X,'Area under the T-CONC Curve WRITE (6,48) M,B,r2 FORMAT (' ' ,8X,'ABS-CONC Regression L1ne:',1X,'Y STOP END ' ,4X,F4.2,3X,'minutes. ' ) ' .4X.F4.2.3X,'minutes. ' ) ' .4X.F4.2.3X, 'minutes.') ' ,4X,F4.2,3X,'minutes. ' ) ' ,2X,F6.2,3X,'minutes2. ' ) ' ,3X,F6.3,2X,'1 i ters . ' ) ' ,3X,F6.3,2X,'mg/1Iter.') ' , 1X.F6.3,'X ' ,F6.3,1X,'(r2 CO ,F5.3, ') ' ) 119 2. Sample Output T a b l e C 1 . Phase I - R e s i d e n c e t ime d i s t r i b u t i o n and o the r e l a t e d d a t a f o r C i r c u l a r Tank #1 w i t h 0 f i s h . TIME REDUCED ABSORBANCE CONCENTRATION E F I (min) TIME (nm) (mg/1) 0 .0 0 .0 0.0 0 .0 0.0 0.0 1 .000 0.5 0 .05 0.074 0 .600 0.067 0.033 0.967 1 .0 0.11 0 .096 0 .790 0.088 0.077 0 .923 1 .5 0 .16 0.112 0 .928 0.103 0. 1 29 0.871 2.0 0.21 0. 130 1 .083 0.121 0. 190 0.810 2.5 0.27 0.114 0 .945 0. 105 0.242 0 .758 3.0 0 .32 0. 1 06 0 .876 0.098 0.291 0 .709 3.5 0. 37 0. 1 02 0 .842 0.094 0.338 0 .662 4 .0 0 .43 0 .099 0 .816 0.091 0 .383 0 .617 4 .5 0 .48 0. 105 0.867 0.097 0.432 0 .568 5.0 0 .53 0.072 0 .583 0 .065 0.464 0 .536 5.5 0 .59 0 .086 0.704 0.078 0 .503 0 .497 6.0 0.64 0 .069 0.557 0.062 0.534 0 .466 6.5 0 .69 0.071 0 .575 0.064 0.566 0.434 7.0 0.74 0.061 0.488 0.054 0.594 0 .406 7.5 0 .80 0 .063 0 .506 0 .056 0.622 0 .378 8.0 0 .85 0 .063 0 .506 0 .056 0.650 0 .350 8.5 0 .90 0 .059 0.471 0.053 0.676 0.324 9.0 0 .96 0 .056 0 .445 0.050 0.701 0 .299 9.5 1.01 0.044 0 .342 0.038 0.720 0 .280 10.0 1 .06 0 .054 0 .428 0.048 0.744 0 .256 10.5 1.12 0.060 0 .480 0.053 0.771 0 .229 11.0 1.17 0.041 0 .316 0 .035 0.788 0 .212 11 .5 1 .22 0.048 0 .376 0.042 0.809 0.191 12.0 1 .28 0.044 0 .342 0.038 0.828 0. 1 72 12.5 1 .33 0.027 0. 1 96 0.022 0 .839 0.161 13.0 1 .38 0 .023 0.161 0.018 0.848 0 . 1 52 13.5 1 .44 0 .019 0 .127 0.014 0.855 0. 1 45 14.0 1 .49 0 .036 0 .273 0.030 0.871 0 . 129 14.5 1 . 54 0 .036 0 .273 0.030 0 .886 0 .114 15.0 1 . 60 0 .035 0 .264 0 .029 0.901 0 .099 15.5 1 .65 0.032 0 .239 0.027 0.914 0 .086 16.0 1 .70 0.032 0 .239 0.027 0.927 0 .073 16.5 1 .76 0 .023 0.161 0.018 0.936 0.064 17.0 1.81 0 .022 0 . 1 53 0.017 0.945 0 .055 17.5 1 .86 0 .023 0.161 0.018 0.954 0 .046 18.0 1 .91 0.027 0. 1 96 0.022 0.964 0 .036 18.5 1 .97 0.031 0 .230 0 .026 0.977 0 .023 19.0 2.02 0.024 0. 1 70 0 .019 0.987 0 .013 19.5 2.07 0 .019 0. 127 0.014 0.994 0 .006 20 .0 2 .13 0.030 0.221 0 .025 1 .006 - . 0 0 6 T h e o r e t i c a l Mean R e s i d e n c e Time 9 .40 m i n u t e s . A c t u a l Mean R e s i d e n c e Time = 7 .06 m i n u t e s . P r o b a b l e F lowing-- th rough Time = 5 .46 m i n u t e s . I n i t i a l Dye Appearance a t O u t l e t = 0 .50 m i n u t e s . V a r i a n c e = 26 .22 m i n u t e s 2 • Dead Volume = 1 1 .723 l i t e r s . A r ea under the T-CONC Curve = 8.973 m g / l i t e r . ABS(X)-CONC(Y) R e g r e s s i o n L i n e : Y= 8.614X - 0 .037 ( r 2 = 0 . 9 8 9 ) 1 20 APPENDIX D - WEIGHT AND LENGTH MEASUREMENTS PHASE I: C i r c u l a r Tank #1 V e r t i c a l Tank #1 Raceway #1 . Wt(g) L t ( cm) Wt(g) L t ( cm) Wt(g) L t ( cm) 15.85 11.3 1 6.05 11.0 29 .82 13.3 20.51 11.5 22 .80 12.5 31 .00 13.8 34 . 18 14.4 24 . 1 0 13.0 20 .83 11.8 23 .76 12.4 21 .13 12.2 21 .72 12.0 2 3 . 6 5 12.0 20 . 18 11.5 19.71 11.7 21 .08 11.6 14.20 10.5 21 .20 12.4 19.81 11.7 25 .20 12.8 1 9 . 5 4 ' 11.7 18.50 11.4 29 .68 13.7 29 .28 13.1 16.47 11.2 23 .65 12.3 21 .47 12.0 30 .53 13.8 1 5.85 1 .1 . 3 23 .96 12.2 2 0 . 4 5 11.5 26 . 1 7 13.0 29 .30 13.2 20 .66 11.8 29 .44 13.6 21 .25 12.0 20 .20 11.7 20 .60 12.0 28 .58 12.9 21 .02 12.0 25 .49 13.0 17.17 11.3 23 .06 12.5 32 .86 13.9 19.08 11.5 30 .00 13.5 38 .04 14.3 21.51 12.0 1 6.92 11.4 31.61 13.8 1 9.90 12.2 26 .39 13.1 20 .00 12.1 18.13 11.2 28 .05 13.1 19.72 11.7 19.51 11.8 23.21 12.5 30 .00 13.5 16.50 11.4 C i r c u l a r Tank #2 V e r t i c a l Tank #2 Raceway #2 Wt (g) Lt (cm) Wt(g) L t ( cm) Wt(g) L t ( cm) 25 .79 12.9 21 .32 12.1 18.80 11.4 25 .75 12.8 30 .55 13.6 21.41 12.2 26 .92 13.0 21 .79 12.0 2 6 . 2 5 12.9 22 . 57 12.6 24 .30 12.5 16.20 11.0 30 .20 13.9 18.53 11.5 29.91 13.7 20 .20 11.8 20 .32 11.8 23 .28 12.5 20 .50 11.7 28 .67 12.9 15.43 11.1 24 .98 12.7 26 .00 12.5 27 .60 1 2.8 24 .84 12.5 26 . 1 7 12.5 20 .60 11.9 16.53 11.2 25.61 12.7 20 .26 12.1 18.40 11.4 34 .98 13.5 15.12 10.9 17.37 11.3 40 .40 14.7 24 .50 12.8 23.61 12.2 30 .20 14.0 26 . 51 12.8 2 5 . 3 5 12.8 21 .68 12.7 1 6.78 11.0 2 3 . 16 12.4 30.61 13.5 2 5 . 6 5 12.6 24.81 12.5 26 .83 13.0 2 8 . 1 3 13.0 2 2 . 12 12.2 20 .70 11.9 34 .40 14.7 22 .67 12.1 21 .50 12.0 17.71 11.5 16.47 11.2 22.31 12.5 1 4.62 11.0 27 .07 13.0 24 .40 13.0 24 .70 12.9 121 PHASE II: C i r c u l a r Tank #1 Vert i c a l Tank #1 Raceway #1 Wt(g) Lt(cm) Wt(g) Lt(cm) Wt(g) Lt(cm) 51 .50 15.6 76.01 17.8 42.41 15.1 42.71 15.1 56.72 16.1 63.32 17.1 40.42 14.9 67.45 16.9 35.53 14.1 41 .96 .14.7 53.36 15.8 46.71 15.3 46. 1 0 15.5 47.60 15.7 62.63 16.5 46.08 15.5 47.80 15.2 39.07 14.9 44.03 15.2 75.75 17.9 38.50 14.7 37.71 14.7 46.79 15.1 47.31 15.6 53. 1 0 16.1 54.85 15.9 45.95 15.9 50.97 15.6 46.50 15.0 37.73 14.8 64.52 17.1 40.72 14.6 57.22 16.6 56.49 16.2 52.31 15.6 58.53 16.6 48.31 15.3 46.65 15.0 53.09 15.7 63.98 16.3 47.02 15.2 38.89 15.0 49.10 15.9 47.24 15.2 40.43 15.0 47.90 14.8 49. 1 1 15.3 67.21 17.0 48.55 15.3 66.78 16.9 72.02 18.4 40.42 14.9 70.81 17.4 52.30 16.1 54. 1 0 15.9 68.43 17.2 41 . 52 15.2 52.79 15.8 49.90 15.9 34.71 14.2 C i r c u l a r Tank #2 Ve r t i c a1 Tank #2 Raceway #2 Wt (g) Lt(cm) Wt(g) Lt(cm) Wt (g) Lt(cm) 52.46 15.9 65.59 17.4 44.42 15.2 48.30 15.9 47.62 15.8 40.87 15.1 56.00 16.0 42.82 14.9 51 .42 16.2 62.81 16.4 62.29 16.3 41 .77 15.1 55.85 16.2 39.62 15.1 31 .78 13.8 33.78 14.5 50.50 15.7 60.20 16.6 43.48 15.6 47.42 15.6 58.53 16.3 52.90 1 6.0 59.09 16.8 49.36 15.6 36.91 14.5 54. 1 4 16.1 57.60 16.6 45.05 15.3 52.20 15.7 48.46 15.9 58.69 16.2 64.46 17.1 53.22 16.5 33.84 14.3 63. 18 17.1 41 .30 15.1 50.84 16.0 74.68 17.8 42.61 15.3 63.00 16.1 62.22 16.7 44.74 15.0 41 .38 14.9 49. 10 15.7 44.73 15.5 50. 17 15.7 74.42 18.0 46.31 15.4 55.70 15.9 60.94 16.8 57.26 16.3 49.71 15.4 48.31 15.4 63.'71 17.0 43.77 14.9 44.75 15.5 54. 1 3 16.3 47.36 15.2 64.52 16.6 51 .34 16.0 1 22 P H A S E I I I : C i r c u l a r Tank #1 V e r t i c a l Wt (g) L t ( cm) Wt (g) 58.61 17.2 61 .30 72 .00 18.0 83 .20 66 .62 17.8 110.28 82.41 18.9 68 .53 65 .52 17.5 67 .60 92 .65 19.5 90 .33 88 .76 19.3 94 .67 67 .78 17.8 70 .00 62 .72 17.1 60.81 83 .74 18.8 61 .10 61 .28 17.3 78.21 71 .10 18.5 74.81 57 .69 17.2 66 . 1 1 84 .57 19.2 78 .90 81 .94 18.8 64 .55 91 .10 19.0 88 .76 9 0 . 1 5 19.4 91.81 61 .49 16.8 97 .67 60 .02 17.3 9 3 . 1 1 69 .46 17.6 80 .58 Tank #1 Raceway #1 L t ( cm) Wt(g) L t ( cm) 16.8 55 .57 16.7 18.7 63 .24 17.1 20 .8 101.80 20 . 1 17.8 78 .82 18.4 17.8 60 .63 17.0 18.1 60 .30 16.7 19.5 96 .42 19.4 17.8 68 .87 17.8 17.3 72.51 18.3 17.2 66.71 17.9 18.2 5 8 . 1 0 16.9 17.9 96 .92 19.8 17.7 68 .55 17.8 18.1 81.51 18.4 17.7 89 .70 19.2 19.0 69 .79 17.7 19.0 88 .50 19.0 19.2 73 .44 18.4 19.1 59 .99 17.4 18.9 56 .08 16.8 C i r c u l a r Tank #2 V e r t i c a l Wt (g) L t ( cm) Wt (g) 66 .85 18.0 78 .38 8 8 . 2 9 19.2 73 .76 77 .42 18.3 102.56 81 .39 18.5 79 .78 73.41 17.9 89 .48 84 .96 18.4 81 .53 98 .90 19.1 70 .40 64 .58 17.4 75 .79 71 .12 17.9 70 .80 66.31 16.8 8 7 . 14 93 .05 19.5 63.21 83 .67 18.6 87 .48 66 .44 17.1 93 .96 60 .56 17.2 69 .02 67 .32 17.5 87 .72 71 .10 17.3 80 .09 74 .79 17.6 70 .08 68 .95 17.5 100.43 66 .20 16.9 74 .06 59 .83 17.0 78 .08 Tank #2 Raceway #2 L t ( cm) Wt (g) L t ( cm) 17.7 8 3 . 3 8 19. 1 18.5 9 3 . 53 19.7 19.5 54 .22 16.5 18.7 60.31 16.8 19.1 64.61 18.0 18.7 53 .50 16.0 17.9 77 .52 18.2 18.2 67 .48 17.6 17.7 8 9 . 0 6 19.2 19.0 87 .67 18.9 17.0 61 .29 17.6 19.8 72 .68 17.9 19.0 98 .64 19.9 18.0 58 .73 17.7 19.0 72 .58 18.1 18.7 85 .73 18.5 17.9 76.61 18.3 20 .0 73 .75 17.9 18.3 82.91 18.3 17.8 84.81 18.4 1 23 PHASE IV : C i r c u l a r Tank #1 V e r t i c a l Wt (g) L t (cm) Wt (g) 99 .00 19.9 94 .63 103.05 19 .5 127.82 90 .82 18.9 95 .37 85 .43 18.8 104.02 129.50 21 .4 86 .34 126.29 2 1 . 6 94 .02 8 5 . 1 6 19.2 100.48 82 .72 18.1 109.39 98 .90 19. 1 118.63 75 .03 18.1 128.24 95 .22 19.5 8 5 . 5 9 94 .57 19.9 90 .02 97 .32 20 .2 94 .58 102.49 19.5 76 .40 80 .20 18.2 114.92 111.58 2 0 . 1 91 .32 99.81 19.8 8 4 . 2 9 97 .24 19.4 96 .77 81 .66 18.1 82 .28 84 .29 18.0 81 .82 Tank #1 Raceway #1 L t ( cm) Wt (g) L t ( cm) 19.1 1 02 .85 19.7 21 .2 69 .79 17.5 19.0 101.51 20 .0 20 .3 73 .20 18.5 18.8 78 .92 18.9 18.9 101.01 19.6 2 0 . 1 81 .03 18.5 20 .7 8 7 . 10 19.7 21.1 76 .32 18.1 21 .4 101.92 19.9 19.3 72 .00 18.1 18.8 91 .03 18.9 18.1 105.48 19.8 18.0 78.71 18.7 20 .5 102.08 20 .2 18.7 81 .72 18.9 18 .5 85.81 18.5 19.7 73 .20 18.0 18.8 94 .39 19.6 18.1 94 .09 19.4 C i r c u l a r Tank #2 wt (g) L t ( cm) 111.30 20 .4 89.41 18.7 106.12 20 .3 134.66 21 .5 90 .53 18.8 7 9 . 1 5 18.3 105.16 20 .2 95 .03 19.6 86 .70 18.8 130.36 20 .5 79 .78 18.7 100.19 20 .0 90 .29 19.9 9 3 . 1 3 19.8 93 .30 19.2 114.43 20 .8 8 7 . 1 2 18.9 82 .40 18.7 105.74 2 0 . 9 111.65 20 .0 V e r t i c a l Tank #2 Wt (g) L t ( cm) 112.89 20 .6 92 .08 19.6 113.13 20 .5 93 .07 19.6 104.29 2 0 . 3 123.55 21 .3 94 .46 19.4 83 .92 18.7 9 9 . 18 19.7 132.88 22 .3 109.50 20 .7 89.31 18.9 84 .40 18.9 82 .33 18.6 1 15.96 20 .4 100. 1 0 20 .0 107.92 20 .2 97 .08 19.6 112.14 20 .5 87.81 19.0 Raceway'^#2 wt (g) L t ( cm) 9 5 . 1 1 19.8 117.09 20 .8 128.49 21 .5 73 .98 18.2 76 .39 18.1 92.21 19.5 104.00 19.9 76.81 18.9 76 .53 18.0 83 .28 18.5 86 .85 19.2 91 .92 19.5 74 . 42 18.6 73 .62 17.9 79 .23 18.1 77 .58 18.3 80 .79 18.7 101.78 19.8 81 .68 19.0 72 .85 18.3 APPENDIX E - ANALYSIS OF VARIANCE TABLES 1. M u l t i p l e R e g r e s s i o n f o r W e i g h t G a i n and C o m p a r i s o n o f R e g r e s s i o n E q u a t i o n s GROUP CIRCU VERT I RACEW DF SS 4 0.44G272E+01 4 O.1060G2E+02 4 0.116113E+01 MS TOTAL DIFFERENCE FOR TESTING SLOPES SUMS DIFFERENCE FOR TESTING LEVELS 12 G 18 2 0.162301E+02 0.135250E+01 0.632992E+02 0.105499E+02 7 .800 FPR0B(.05)= 0.300486E+01 FPR0B( .O1)= 0.484503E+01 0.795293E+02 0.441829E+01 0.235622E+03 0.117811E+03 26.664 FPR0B(.O5)= 0.355455E+01 FPR0B( .O1)= 0.601290E+01 4* COMBINED REGRESSION 20 0.315152E+03 REGRESSION COEFFICIENTS CIRCU 0 . l 5 3 G 0 5 E + 0 2 -0 . 7 1 39 10E+00 0. 295691E+00 -0 . 5 ^ 4 2 E + 0 1 VERTI O 1 0 ° 8 7 6 E + 0 3 -O.963976E+00 0.425943E+00 -0 .672775E+0 RACEW o ' .G43097E + 02 - O . G67888E+00 0 . 4 2 5 4 5 7 E + 0 0 -0.387936E+01 8 2 B 3 GROUP CIRCU RACEW TOTAL DIFFERENCE FOR TESTING SLOPES SUMS DIFFERENCE FOR TESTING LEVELS COMBINED REGRESSION GROUP CIRCU VERT I TOTAL DIFFERENCE FOR TESTING SLOPES SUMS DIFFERENCE FOR TESTING LEVELS COMBINED REGRESSION DF SS MS 4 0.446272E+01 4 0.116113E+01 8 0.562386E+01 0 .702982E*00 3 0.308542E+02 0.102847E+02 14.630 FPR0B(.O5)= 0.423436E+01 F P R O B ( . O I ) ' 0 .796233E+0I 11 0.364780E+02 0.331618E+01 1 0.386179E+02 0.386179E+02 11.645 FPR0B(.O5)= 0.484420E+01 FPR0B( .O1)= 0.9S4977E+01 I 12 0.750959E+02 DF SS MS F 4 0.446272E+01 4 0.106062E+02 8 0.150S89E+02 0.188362E+01 3 0.139279E+02 0.464263E+01 2 .465 FPR0B(.05)= 0.423436E+01 FPR0B( .01)= O . 796233E-* 01 11 O. 289.968E +02 0 . 263608E+01 1 0.826006E+02 0.826006E+02 3 1.335 FPR0B(.05)= 0 . 484<120E+01 FPR0B( .O1)= 0.964977E+01 12 0.111597E+03 GROUP VERT I RACEW DF SS 0.106062E+02 0.116113E+01 MS TOTAL DIFFERENCE FOR TESTING SLOPES SUMS DIFFERENCE FOR TESTING LEVELS 8 3 0.117673E+02 0.147092E+01 0.428276E+02 0 . 142759E+02 9 ™ 5 . 7 Q , „ 1 F + n 1 FPROBf .05)= 0.423436E+01 FPROB( .01 ) = 0.796233E+01 11 0.545950E+02 0.496318E+01 1 n 205771E+03 0.205771E+03 4 1.459 1 0 2 0 5 7 7 1 % ^ O B ( U 0 5 ) = 0 4 8 4 4 2 0 E + 0 , FPR0B( .01 )= 0.964977E+01 COMBINED REGRESSION 12 0.260365E+03 2. A n a l y s i s of V a r i a n c e f o r P e r c e n t Weight G a i n (dW/Wo) Source TANK PHASE TANK+PHASE Res i dua1 Total Sum of squares 0. 40001 6 . 876G 0.69577E-01 0.20128E-01 7.3663 DF 2 . 3. 6 . 12 . 23 . Mean square 0. 20001 2 . 2922 0.11596E-01 0.16773E-02 F-ra 11 o 119.24 1366.6 6 .9137 Probability Test term 0.00000 0.00000 0.00233 RESIDUAL RESIDUAL RESIDUAL PCWTGN Overal1 mean 0. 87954 Overal1 standard deviation 0.56593 Means for TANK 1 . 2 . 3 . 0 MEAN 0.85850 1.0471 0.73300 0 STDV 0.55252 0.62123 0.55134 Multiple range tests Duncan test at 5% probability level There are 3 homogeneous subsets which are listed as follows: ( 3. ) ( 1. ) ( 2. ) Means for PHASE .1 .2 .3 .4 0 MEAN 1.5833 1.1973 0.48700 0.25050 0 STDV 0.15066 0.22485 0.13711 0.76730E-01 Multiple range tests Duncan test at 57. probability level There are 4 homogeneous subsets which are listed as follows: ( 4 ) ( 3 ) ( .2 ) ( . 1 ) NO CO Multiple range tests for TANK*PHASE Duncan test at 5% probability level There are 8 homogeneous subsets which are listed as follows: ( 3 4, 1 4 ) ( 3 3 . 2 4 ) ( 1 3 ) ( 2 3 ) ( 3 2 ) ( 1 2 ) ( 2 2 . 3 1 . 1 1 ) ( 2 1 ) 3 . M u l t i p l e R e g r e s s i o n f o r Length G a i n and Comparison o f R e g r e s s i o n E q u a t i o n s GROUP DF SS MS CIRCU 4 0 .697384E-01 V E R U 4 0.244880E+00 RACEW 4 O. 129-175E-01 TOTAL 12 DIFFERENCE FOR TESTING SLOPES 6 SUMS 18 DIFFERENCE FOR TESTING LEVELS 2 COMBINED REGRESSION 20 0.327536E+00 0 .272946E-01 0.158686E+00 0 .264476E-01 0 .969 FPR0B(.05)= 0.300486E+01 FPR0B( .01 )= 0.484503E+01 O.48G2P1E+00 0 .270123E-01 0.139035E+01 0.695175E+00 25.73G FPR0B(.05)= 0.355455E+01 FPR0B( .O1)= 0.601290E+01 0. 187657E+01 REGRESSION COEFFICIENTS CIRCU VERTI RACEW B O 0 . 166163E+02 0 . 208357E+O2 O.160507E+02 B 1 -0 .825809E+00 -O.104284E+01 -O.857746E+00 B 2 O. 493748E-01 0 .674785E-01 0 .666346E-01 B 3 -O.499901E+00 -0.661087E+00 -0.474916E+00 GROUP CIRCU RACEW TOTAL DIFFERENCE FOR TESTING SLOPES SUMS DIFFERENCE FOR TESTING LEVELS COMBINED REGRESSION GROUP CIRCU VERTI TOTAL DIFFERENCE FOR TESTING SLOPES SUMS DIFFERENCE FOR TESTING LEVELS COMBINED REGRESSION DF SS .0.697384E-01 0 .129175E-01 MS 8 3 1 1 1 0 .826559E-01 0 .103320E-01 0.116084E+00 0 .386947E-01 3 .745 FPR0B( .05)= 0.423436E+01 FPR0B( .01 )= 0.796233E+01 O.198740E+00 0 .180673E-01 0 .876980E-01 0.876980E-01 4.854 FPR0B(.05)= 0.484420E+01 FPR0B( .01)= 0.964977E+01 O 12 0.286438E+00 DF SS MS 4 O.697384E-01 4 0.244880E+00 8 0.314618E+00 0 .393273E-01 3 0 .711393E-01 0 .237131E-01 0 .603 FPR0B(.O5)= 0.423436E+01 FPR0B( .O1)= 0.796233E+01 11 0.385757E+00 0 .350689E-01 1 0 .7 12296E+00 0.7I2296E+00 20.311 FPR0B(.O5)= 0.484420E+01 FPR0B( .O1)= 0.964977E+01 12 O.109805E+01 GROUP VERTI RACEW TOTAL DIFFERENCE FOR TESTING SLOPES SUMS DIFFERENCE FOR TESTING LEVELS COMBINED REGRESSION DF SS MS 4 0.244880E+00 4 0.129175E-01 8 0.257797E+00 0.322247E-01 3 0.420837E-01 0.140279E-01 0.435 FPR0B(.O5)= 0.42343GE+01 FPR0B(.01)= 0.796233E+01 11 0.299881E+00 0.272619E-01 1 0.107939E+01 0.107939E+01 39.593 FPR0B(.O5)= 0.484420E+01 FPR0B(.01)= 0.964977E+01 12 0.137927E+01 4. A n a l y s i s o f V a r i a n c e f o r L e n g t h G a i n (dL) Source TANK PHASE TANK*PHASE Res i dua1 Total dL Sum of squares 2 . 2038 18.131 0. 15583 0.26710 20.758 Overa11 mean 2.5767 DF 2 . 3 . 6. 12 . 23 . Mean square Overa11 standard deviation 0.95001 F-rat1o 1 . 1019 49 . 505 6.0438 271.53 0.25971E-01 1.1668 0.22258E-01 Means for TANK 1 . 2 . 0 MEAN 2.4725 2.9887 0 STDV 0.94433 0.93967 Multiple range tests 2 . 2687 0. 93588 Duncan test at 5% probability level There are 3 homogeneous subsets which are listed as follows: ( 3. ) ( 1. ) ( 2. ) Means for PHASE . 1 0 MEAN 3.2717 3.4183 2.3783 1.2383 0 STDV 0.23284 0.39107 0.45314 0.33594 Probability Test term 0.00000 0.OOOOO 0. 38463 RESIDUAL RESIDUAL RESIDUAL Multiple range tests Duncan test at 5% probability level There are 3 homogeneous subsets which are listed as follows: ( .4 ) ( 3 ) ( . 1 . 2 ) Multiple range tests for TANK*PHASE F-ratlo 1s not significant at probability 0.38463 5'. A n a l y s i s o f V a r i a n c e f o r F e e d C o n v e r s i o n R a t i o (FCR) Sum of Mean Source squares DF square F-rat1o Probabl11ty Test term TANK 2.5131 2 . 1.2565 216.95 0.00000 RESIDUAL PHASE 1 .7667 3. 0.58891 101.68 0.00000 RESIDUAL TANK+PHASE 0.62664 6 . 0.10444 18.033 0.00002 RESIDUAL Res 1dua1 0.69500E-01 12 . 0.57917E-02 Total 4.9759 23 . Overa11 Overa11 mean standard deviation FCR 1.8033 0 .46513 Means for TANK 1 . 2 . 3 0 MEAN 1 . 7950 1.4112 2.2037 0 STDV O.22425 0.17988 0 .51884 Multiple range tests Duncan test at 5% probabl11ty 1 evel There are 3 homogeneous subsets wh 1 ch are 11sted as foilOWS: ( 2. ) ( 1. ) ( 3. ) Means for PHASE .1 .2 .3 .4 0 MEAN 1.5083 1.6250 2.2183 1.8617 0 STDV 0.15355 0.23914 0.53831 0.52086 Multiple range tests Duncan test at 5% probability level There are 4 homogeneous subsets which are listed as follows ( . 1 ) I .2 ) ( 4 ) ( .3 ) Multiple range tests for TANK *PHASE Duncan test at 5% probability level There are 6 homogeneous subsets which are listed as follows: 2 4 2 1 2 2 ) 1 1 3 1 1 2 . 2 1 4 3 2 ) 1 3 ) 3 4 ) 3 3 ) 6. Analysis of Variance for Condition Factor (CF) Source TANK PHASE TANK *PHASE Residual Total Sum of squares 0.49000E-06 0.16312E-05 0.27000E-06 0.6G500E-06 0.305G2E-05 DF 2 . 3. 6 . 12. 23. Mean square 0.24500E-06 0.54375E-06 0.4 5000E-07 0.55417E-07 F-rat 1o 4 .4210 9.8120 0.81203 Probability Test term 0.03G43 0 . 001 50 0. 58037 RESIDUAL RESIDUAL RESIDUAL CF Overal1 mean 0. 12738E-01 Overa11 standard deviation 0.36453E-03 Means for TANK 1 . 0 MEAN 0 STDV 0. 12812E-01 0.37962E-03 0.12862E-01 0. 44058E-03 0.12537E-01 0.16850E-03 LO 0> Multiple range tests Duncan test at 5% probability level There are 2 homogeneous subsets which are listed as follows: 2. ) Means for PHASE . 1 0 MEAN 0 STDV 12350E-01 13784E-03 0.13000E-01 0.3741GE-03 0. 12650E-01 0.24290E-03 0.12950E-01 0.25884E-03 Multiple range tests Duncan test at 57, probability level There are 3 homogeneous subsets which are listed as follows: ( . 1 ) ( .3 ) ( -4. .2 ) Multiple range tests for TANK * PHASE F-ratio is not significant at probability 0.58037 1 38 APPENDIX F - L IST OF ABSORBANCES Tab l e E 1 . Phase I -Measured abso rbances a t C i r c u l a r Tank #1. TIME NO. OF F ISH—> 0 1 5 30 45 1 00 (min) (nm) 0.0 0 .0 0.0 0.0 0 .0 . 0 .0 0.5 ' 0 .074 0.080 0.088 0.111 0. 130 1.0 0 .096 0. 105 0.110 0. 1 27 0. 135 1.5 0 .112 0 .115 0. 1 22 0.118 0 .135 2.0 0. 1 30 0.131 0.113 0 .112 0.131 2.5 0 .114 0. 1 20 0.099 0 .093 0. 107 3.0 0. 1 06 0. 1 02 0.097 0.091 0. 103 3.5 0. 1 02 0.092 0.096 0 .089 0 .078 4 .0 0 .099 0.089 0.082 0 .075 0.071 4 .5 0. 105 0.087 0 .079 0 .080 0 .069 5.0 0 .072 0 .085 0.073 0 .087 0.097 5.5 0 .086 0.080 0.068 0.087 0.090 6.0 0 .069 0 .075 0.065 0.084 0 .085 6 .5 0.071 0.073 0.064 0 .068 0.077 7.0 0.061 0.070 0.066 0 .066 0.054 7.5 0 .063 0.069 0.063 0 .059 0.070 8.0 0 .063 0.064 0.060 0 .062 0 .079 8.5 0 .059 0.061 0.063 0 .059 0.062 9.0 0 .056 0.060 0.062 0 .049 0 .043 9.5 0 .044 0.058 0 .055 0.052 0.058 10.0 0 .054 0.057 0 .046 0.051 0.071 10.5 0 .060 0.055 0.042 0.052 0.032 11 .0 0.041 0.051 0.037 0 .050 0.062 11 .5 0 .048 0.046 0.041 0 .048 0.053 12.0 0 .044 0.043 0.040 0.051 0.037 12.5 0 .027 0.041 0.037 0 .043 0 .029 13.0 0 .023 0 .035 0.036 0 .043 0.032 13 .5 0 .019 0 .035 0 .035 0 .042 0.028 14.0 0 .036 0.031 0.033 0 .036 0.040 14.5 0 .036 0.027 0.034 0.034 0 .026 15.0 0 .035 0.028 0.030 0.031 0.038 15.5 0 .032 0.027 0.030 0.031 0.034 16.0 0 .032 0 .025 0.028 0 .030 0.022 16.5 0 .023 0.023 0 .025 0 .029 0 .019 17.0 0 .022 0.024 0.027 0.032 0 .025 17 .5 0 .023 0.020 0 .026 0 .026 0.024 18.0 0 .027 0.022 0.024 0 .022 0.021 18.5 0.031 0 .019 0.018 0.018 0.039 19.0 0 .024 0.018 0.016 0.018 0.022 19.5 " 0 .019 0.020 0.020 0.020 0.024 20 .0 0 .030 0.016 0.016 0 .016 0 .016 Abso rbance (X ) - C o n c e n t r a t i o n ( Y ) R e g r e s s i o n E q u a t i o n : Y = 8.614X - 0 .037 ( r 2 = 0 .989) 1 39 T a b l e E2 . Phase I -Measured abso rbances a t C i r c u l a r Tank #2. TIME NO. OF FISH--> 0 (min) 0 .0 0.0 0 .5 0 .054 1 .0 0 .084 1 .5 0 .095 2.0 0 . 1 07 2.5 0 .094 3.0 0 .090 3.5 0 .085 4 .0 0 .083 4 .5 0 .078 5.0 0 .074 5.5 0 .066 6 .0 0 .064 6 .5 0 .062 7.0 0 .059 7.5 0 .059 8.0 0 .055 8.5 0 .048 9 .0 0 .044 9 .5 0 .047 10.0 0 .044 10 .5 0 .043 11.0 0.041 11 .5 0 .036 12.0 0 .033 12 .5 0.032 13.0 0.032 13 .5 0 .030 14.0 0 .029 14.5 0.028 15.0 0 .026 15 .5 0 .025 16.0 0.024 16 .5 0.022 17.0 0 .023 17 .5 0 .020 18.0 0.021 18.5 0 .019 19.0 0 .018 19 .5 0 .014 20 .0 0 .012 15 30 45 100 (nm) 0. 0 0. 0 0 . 0 0 . 0 0 . 080 0. 096 0 . 082 0. 108 0. 099 0. 099 0. 1 06 0. 109 0. 109 0. 1 1 4 0 . 109 0. 098 0. 1 06 0. 101 0. 102 0 . 097 0. 098 0. 092 0. 097 . 0 . 087 0. 094 0. 094 0. 084 0. 100 0. 091 0. 089 0 . 091 0. 096 0. 082 0. 089 0 . 076 0. 083 0. 073 0. 086 0. 064 0 . 073 0. 065 0. 072 0. 064 0. 072 0. 065 0. 075 0. 063 0. 076 0. 063 0. 071 0. 069 0. 075 0. 062 0. 069 0. 059 0. 067 0. 061 0. 062 0. 058 0. 057 0. 060 0. 059 0. 061 0. 052 0. 057 0. 057 0. 054 0. 070 0. 058 0. 046 0 . 046 0. 059 0. 045 0. 048 0 . 052 0. 062 0. 043 0. 045 0. 046 0. 046 0. 041 0. 043 0. 044 0. 039 0. 033 0. 038 0. 031 0. 035 0. 03.6 0 . 034 0. 034 0. 039 0. 035 0. 033 0. 029 0. 031 0. 032 0. 033 0. 026 0. 027 0. 035 0. 032 0 . 041 0. 029 0. 031 0. 030 0. 027 0 . 029 0. 029 0. 031 0. 039 0. 017 0. 029 0. 024 0. 038 0. 026 0. 028 0. 022 0. 026 0 . 015 0. 026 0. 021 0. 033 0. 038 0. 027 0. 023 0. 026 0. 019 0. 024 0. 020 0. 017 0. 008 0. 025 0. 021 0. 019 0. 029 0. 022 0. 019 0. 01 1 0. 030 0. 020 0. 019 0. 020 0. 026 0. 018 0. 017 0. 019 0. 009 0. 013 0. 022 0. 006 0. 018 0. 017 0. 020 0. 027 0. 026 0. 014 0. 018 0. 013 0. 005 0. ,012 0. 016 0. 004 0. .007 Abso rbance (X ) - C o n c e n t r a t i o n ( Y ) R e g r e s s i o n E q u a t i o n : Y = 9.656X - 0 .034 ( r 2 = 0 .995) 140 T a b l e E 3 . Phase I -Measured TIME NO. OF F I S H — > 0 (min) 0 .0 0.0 0 .5 0.031 1 .0 0.086 1 .5 0.096 2.0 0.097 2.5 0.084 3.0 0.083 3.5 0 .070 4 .0 0.061 4 .5 0.068 5.0 0.062 5.5 0 .059 6.0 0.053 6 .5 0 .059 7.0 0 .058 7.5 0.062 8.0 0 .043 8.5 0.044 9.0 0.041 9.5 0.053 10.0 0.042 10 .5 0 .039 11.0 0.032 11 .5 0.048 12.0 0 .040 12.5 0 .035 13.0 0.032 13.5 0 .030 14.0 0.031 14.5 0.028 15.0 0.032 15 .5 0.026 16.0 0.032 16.5 0 .026 17.0 0.021 17.5 0 .016 18.0 0 .019 18.5 0 .016 19.0 0 .013 19.5 0 .013 20 .0 0 .008 Abso rbance (X ) - C o n c e n t r a t i o n a b s o r b a n c e s a t V e r t i c a l Tank #1. 15 30 45 100 (nm) 0 . 0 0. 0 0 . 0 0 .0 0 . 028 0. 1 37 0. 052 0 .037 0 . 101 0. 1 07 0. 1 03 0. .093 0 . 081 0. 111 0. 096 0 .101 0 . 084 0. 108 0. 1 07 0 .104 0 . 086 0. 096 0. 093 0 .091 0 . 076 0. 096 0. 098 0 .091 0 . 084 0. 087 0. 077 0 .079 0 . 079 0. 068 0. 086 0 .081 0 . 074 0. 091 0. 083 0 .094 0 . 071 0. 069 0. 079 0 .074 0 . 072 0. 064 0. 071 0 .069 0 . 063 0. 053 0. 069 0 .067 0 . 060 0. 056 0. 064 0 .064 0 . 049 0. 046 0. 057 0 .064 0 . 051 0. 050 0. 057 0 .064 0 . 053 0. 052 0. 059 0 .063 0 . 045 0. 059 0. 056 0 .051 0 . 044 0. 059 0. 044 0 .059 0 . 039 0. 046 0. 049 0 .054 0 . 037 0. 049 0. 036 0 .053 0 . 041 0. 050 0. 042 0 .037 0 . 044 0. 045 0. 050 0 .041 0 . 038 0. 030 0. 036 0 .035 0 . 033 0. 036 0. 039 0 .026 0 . 037 0. 038 0. 038 0 .037 0 . 034 0. 033 0. 048 0 .034 0 . 029 0. 022 0. 031 0 .025 0 . 014 0. 030 0. 032 0 .029 0 . 024 0. 033 0. 025 0 .031 0 . 024 0. 038 0. 022 0 .028 0 . 030 0. 021 0. 038 0 .028 0 . 014 0. 029 0. 031 0 .025 0 . 023 0. 037 0. 023 0 .023 0 . 014 0. 024 0. 034 0 .018 0 . 032 0. 026 0. 034 0 .016 0 . 029 0. 019 0. 018 0 .014 0 . 027 0. 017 0. 018 0 .023 0 . 018 0. 025 0. 019 0 .014 0 . 023 0. 029 0. 019 0 .022 0 . 023 0. 019 0. 016 0 .013 R e g r e s s i o n E q u a t i o n : Y = 10.409X - 0.028 ( r 2 = 0 .997) 141 T a b l e E4 . Phase I -Measured a b s o r b a n c e s a t V e r t i c a l Tank #2. TIME NO. OF FISH--> 0 1 5 30 45 100 (min) (nm) 0 .0 0.0 0 .0 0.0 0.0 0.0 0.5 0 .065 0 .060 0 .056 0 .006 0 .025 1 .0 0.071 0 .082 0.081 0.066 0.114 1 .5 0 .099 0 .094 0 .096 0.099 0.104 2.0 0 .095 0 .090 0 .096 0. 1 02 0 .099 2.5- 0.087 0 .088 0 .086 0. 103 0 .096 3.0 0.081 0 .084 0.086 0.097 0 .092 3.5 0.081 0 .075 0.079 0.088 0.071 4 .0 0.078 0 .073 0.082 0.086 0 .075 4 .5 0.066 0 .070 0 .076 0.066 0 .083 5.0 0.074 0 .070 0.064 0 .096 0 .066 5.5 0.072 0 .065 0.076 0.072 0.064 6.0 0 .056 0 .069 0.046 0.067 0 .066 6.5 0 .055 0 .060 0.066 0.062 0.061 7.0 0.052 0 .056 0.052 0.066 0 .069 7.5 0.050 0 .054 0.050 0.054 0 .048 8.0 0 .049 0.051 0.046 0.032 0 .046 8.5 0.047 0 .049 0.046 0.064 0 .053 9.0 0.051 0.051 0.042 0.046 0.044 9.5 0.050 0 .053 0.040 0.053 0.044 10.0 0.050 0 .048 0.034 0.044 0 .049 10.5 0.047 0.046' 0 .035 0 .039 0 .035 11.0 0.046 0 .043 0.028 0.041 0.034 11 .5 0 .046 0 .042 0.027 0.039 0 .032 12.0 0.041 0 .045 0.028 0.034 0.031 12.5 0 .049 0 .034 0.027 0.027 0 .029 13.0 0 .039 0 .034 0 .029 0 .026 0 .029 13.5 0 .036 0 .032 0.030 0.029 0 .035 14.0 0.041 0.031 0.025 0.032 0 .025 14.5 0 .029 0 .027 0.034 0 .035 0.021 15.0 0.026 0 .029 0.028 0.024 0 .029 15.5 0 .029 0 .024 0.027 0.022 0.023 16.0 0.018 0 .024 0.025 0.019 0.021 16.5 0 .020 0 .018 0.021 0.014 0 .019 17.0 0 .019 0 .017 0.019 0.024 0.017 17.5 0 .029 0 .015 0.018 0.021 0 .019 18.0 0.022 0 .012 0 .016 0.009 0.014 18.5 0.014 0 .010 0 .019 0 .009 0.018 19.0 0.017 0 .009 0 .015 0.008 0 .010 19 .5 0.013 0 .014 0.014 0.009 0.021 20 .0 0.021 0 .008 0.010 0.012 0.014 Abso rbance (X ) - C o n c e n t r a t i o n ( Y ) R e g r e s s i o n E q u a t i o n : Y = 8.002X + 0.073 ( r 2 = 0 .990) 1 42 Table E5. Phase I -Measured absorbances at Raceway #1. TIME NO. OF FISH—> 0 (min) 0.0 0.0 0.5 0.0 1 .0 0.0 1.5 0.0 2.0 0.0 2.5 0.0 3.0 0.033 3.5 0.080 4.0 0.096 4.5 0. 1 20 5.0 0. 1 28 5.5 0. 1 45 6.0 0. 1 39 6.5 0. 1 44 7.0 0. 1 42 7.5 0. 132 8.0 0. 1 22 8.5 0.113 9.0 0. 1 06 9.5 0.099 10.0 0.084 10.5 0.072 11.0 0.066 11.5 0.066 12.0 0.058 12.5 0.053 13.0 0.043 13.5 0.042 14.0 0.037 14.5 0.034 15.0 0.034 15.5 0.031 16.0 0.024 16.5 0.023 17.0 0.022 17.5 0.016 18.0 0.016 18.5 0.014 19.0 0.008 19.5 0.014 20.0 0.006 Absorbances(X) - Concentration 15 30 45 100 (nm) 0. 0 0. 0 0. 0 0. 0 0. 0 0. 0 0. 0 0. 0 0. 0 0. 0 0. 0 0. 0 0. 01 1 0. 0 0. 013 0. 020 0. 014 0. 008 0. 029 0. 048 0. 038 0. 038 0. 061 0. 059 0. 064 0. 066 0. 073 0. 088 0. 083 0. 086 0. 1 0.7 0. 1 16 0. 1 04 0. 1 04 0. 1 16 0. 1 33 0. 1 1 6 0. 1 1 2 0. 1 26 0. 1 46 0. 1 32 0. 129 0. 1 36 0. 1 55 0. 1 32 0. 131 0. 1 38 0. 1 64 0. 1 34 0. 1 26 0. 1 46 0. 161 0. 1 30 0. 1 29 0. 1 28 0. 1 46 0. 1 29 0. 1 22 0. 1 32 0. 1 46 0. 1 29 0. 1 26 0. 1 25 0. 1 43 0. 1 1 4 0. 121 0. 1 18 0. 1 32 0. 1 04 0. 1 1 4 0. 1 1 2 0. 1 17 0. 1 02 0. 098 0. 1 1 1 0. 1 1 3 0. 1 00 0. 091 0. 100 0. 1 00 0. 086 0. 087 0. 088 0. 096 0. 076 0. 069 0. 082 0. 071 0. 074 0. 078 0. 073 0. 074 0. 070 0. 063 0. 066 0. 066 0. 054 0. 062 0. 063 0. 074 0. 052 0. 056 0. 058 0. 052 0. 051 0. 047 0. 049 0. 039 0. 039 0. 042 0. 046 0. 038 0. 042 0. 040 0. 039 0. 038 0. 037 0. 031 0. 028 0. 034 0. 027 0. 034 0. 032 0. 027 0. 027 0. 019 0. 029 0. 020 0. 025 0. 026 0. 027 0. 014 0. 022 0. 016 0. 025 0. 014 0. 016 0. 028 0. 021 0. 016 0. 014 0. 024 0. 018 0. 014 0. 016 0. 014 0. 017 0. 013 0. 018 0. 01 1 0. 016 0. 012 0. 009 0. 011 0. 008 0. 005 0. 008 0. 010 0. 007 0. 005 0. 006 0. 009 0. 005 0. .007 (Y) Regression Equation: Y = 7.907X - 0.026 ( r 2 = 0.988) 143 Tabl -e E6 . Phase I -Measured a b s o r b a n c e s a t Raceway #2. TIME NO. OF F ISH—> 0 (min) 0 .0 0.0 0.5 0 .0 1.0 0 .0 1 .5 0 .0 2.0 0 .0 2.5 0 .0 3.0 0 .0 3.5 0 .053 4 .0 0 .083 4 .5 0.111 5.0 0 . 1 53 5.5 0. 1 65 6.0 0. 1 74 6 .5 0. 1 67 7.0 0 . 1 64 7.5 0. 1 49 8.0 0. 1 36 8.5 0. 1 26 9.0 0.111 9.5 0 .096 10.0 0 .095 10.5 0.081 11.0 0 .084 11 .5 0 .067 12.0 0.052 12.5 0 .052 13.0 0 .046 13.5 0 .049 14.0 0 .034 14.5 0 .026 15.0 0 .023 15.5 0 .023 16.0 0 .030 16.5 0 .019 17.0 0 .019 17.5 0.021 18.0 0 .018 18.5 0 .014 19.0 0 .012 19.5 0 .024 20 .0 0 .019 15 30 45 100 (nm) 0 . 0 0 . 0 0 . 0 0. 0 0 . 0 0 . 0 0 . 0 0 . 0 0 . 0 0 . 0 0 . 0 0. 0 0 . 0 0 . 0 0 . 0 0. 008 0. 0 0 . 026 . 0 . 013 0. 027 0. 0 0 . 068 0. 041 0. 054 0. 031 0 . 068 0. 050 0. 076 0 . 053 0. 078 0. 076 0. 1 03 0 . 069 0. 100 0. 101 0. 1 19 0. 093 0. 1 25 0. 1 20 0. 1 26 0. 101 0 . 1 28 0. 1 22 0. 134 0 . 1 1 5 0. 147 0. 1 35 0. 1 48 0. 131 0. 1 50 0. 1 36 0. 1 29 0. 1 40 0. 1 36 0. 1 48 0. 1 38 0. 1 37 0. 1 40 0. 1 53 0. 1 30 0. 131 0. 1 45 0. 1 36 0. 1 24 0. 1 30 0. 1 30 0. 121 0. 121 0. 1 26 0. 1 27 0. 1 06 0. 101 0. 1 24 0. 1 1 3 0. 1 1 5 0. 099 0 . 1 22 0. 1 1 1 0. 1 00 0. 086 0. 1 10 0. 099 0. 098 0. 091 0. 098 0. 089 0. 091 0. 084 0. 095 0 . 084 0. 078 0. 068 0. 087 0. 072 0. 076 0. 062 0 . 077 0. 053 0 . 071 0. 061 0. 065 0 . 059 0. 062 0. 042 0. 059 0 . 046 0. 061 0. 046 0 . 054 0. 050 0 . 057 0. 050 0. 046 0. 042 0. 041 0. 040 0. 042 0. 041 0. 028 0. 030 0. 034 0. 030 0 . 031 0. 032 0 . 030 0 . 027 0. 025 0. 025 0. 028 0 . 029 0. 028 0. 015 0. 027 0. 026 0. 029 0. 022 0. 024 0. 020 0 . 023 0. 014 0. 020 0. 019 0. 019 0. 020 0. 018 0. 019 0. 023 0. 018 0. 017 0 . 017 0. 009 0. 017 0. 016 0. 009 0. 014 0. 015 0. 012 0. 008 0. 009 0. 014 0. 008 0. 012 0. 008 0. 009 Abso rbance (X ) - C o n c e n t r a t i o n ( Y ) R e g r e s s i o n E q u a t i o n : Y = 8.735X - 0.053 ( r 2 = 0 .996) 1 44 T a b l e E7 . Phase I I -Measured a b s o r b a n c e s a t C i r c u l a r Tank #1. TIME NO. OF F ISH—> 0 15 30 45 100 (min) (nm) 0 .0 0.0 0 .0 0.0 0 .0 0 .0 0 .5 0 .069 0. 1 20 0.131 0.141 0. 1 48 1 .0 0 .069 0.131 0. 146 0. 1 45 0.171 1 .5 0 . 106 0.151 0. 153 0. 1 56 0.161 2.0 0.111 0. 1 22 0.151 0 .132 0. 1 32 2.5 0. 120 0. 1 26 0.1 36 0. 129 0. 1 42 3.0 0. 109 0.131 0.117 0. 1 39 0. 1 48 3.5 0. 129 0.114 0. 1 24 0 .133 0.131 4 .0 0. 107 0. 1 03 0.123 0.112 0.111 4 .5 0 .097 0 .079 0.088 0.111 0. 106 5.0 0 .096 0 .096 0.095 0.083 0.098 5.5 0. 100 0 .082 0. 106 0 .083 0.083 6.0 0 .092 0 .098 0 .089 0.084 0. 104 6 .5 0 .076 0 .066 0.068 0.082 0.092 7.0 0 .086 0.077 0.081 0.061 0 .083 7.5 0 .069 0 .073 0.078 0.071 0.076 8.0 0 .046 0.061 0.072 0.074 0.060 8 .5 0.071 0.077 0.058 0.067 0.074 9.0 0 .046 0.044 0.078 0 .042 0.078 9.5 0 .076 0 .052 0.064 0 .048 0.066 10.0 0 .048 0.047 0 .065 0.062 0.047 10 .5 0 .064 0 .038 0 .053 0.048 0.042 11.0 0 .048 0.044 0.054 0 .052 0.062 11 .5 0.041 0 .038 0.051 0.048 0.047 12.0 0.024 0 .053 0.021 0.051 0.048 12 .5 0 .027 0 .036 0.038 0 .055 0.040 13.0 0 .042 0.028 0 .036 0.028 0.052 13 .5 0 .023 0.031 0.037 0 .040 0.044 14.0 0.034 0 .039 0 .049 0.048 0.037 14 .5 0.018 0 .034 0.032 0.031 0.046 15.0 0.024 0.018 0 .033 0 .023 0.012 15 .5 0.041 0.021 0.026 0 .040 0.020 16.0 0 .016 0 .025 0.019 0 .037 0.018 16 .5 0 .029 0.031 0 .023 0.032 0.034 17.0 0 .023 0 .022 0.013 0.027 0 .023 17.5 0 .019 0.027 0.018 0 .017 0.014 18.0 0 .016 0 .013 0.021 0 .019 0.038 18 .5 0 .026 0 .016 0.031 0.022 0.016 19.0 0 .010 0 .015 0.038 0.024 0 .015 19.5 0.012 0.021 0.008 0 .008 0 .019 20 .0 0.017 0 .016 0 .013 0 .002 0.026 Abso rbance (X ) - C o n c e n t r a t i o n ( Y ) R e g r e s s i o n E q u a t i o n : Y = 5.340X + 0 .127 ( r 2 = 0 .997) 1 45 Table E8. Phase II -Measured absorbances at C i r c u l a r Tank #2. TIME NO. OF FISH—> 0 15 30 45 100 (min) (nm) 0.0 0.0 0.0 0.0 0.0 0.0 0.5 0.069 0.067 0. 1 34 0. 1 36 0. 1 50 1 .0 0. 106 0. 136 0.141 0. 1 46 0. 1 55 1 .5 0. 1 20 0. 124 0. 1 46 0.119 0. 104 2.0 0. 100 0. 1 36 0. 1 50 0.121 0. 145 2.5 0. 1 20 0.131 0. 1 38 0.134 0. 146 3.0 0. 102 0. 122 0. 109 0.119 0.126 3.5 0.097 0.133 0. 105 0.119 0. 107 4.0 0. 1 08 0. 107 0. 129 0. 108 0. 108 4.5 0.034 0. 107 0.094 0.094 0.093 5.0 0.089 0. 104 0.091 0.071 0.079 5.5 0.096 0. 1 02 0.093 0.089 0.089 6.0 0.093 0.075 0.093 0.098 0.085 6.5 0.051 0.078 0.089 0.088 0.074 7.0 0.075 0.075 0.059 0.081 0.087 7.5 0.072 0.074 0.084 0.068 0.056 8.0 0.061 0.072 0.068 0.029 0.067 8.5 0.072 0.070 0.060 0.024 0.072 9.0 0.065 0.059 0.074 0.067 0.059 9.5 0.045 0.071 0.043 0.046 0.056 10.0 0.052 0.065 0.050 0.045 0.059 10.5 0.042 0.052 0.050 0.044 0.019 11.0 0.053 0.031 0.029 0.039 0.053 11.5 0.028 0.055 0.057 0.043 0.044 12.0 0.031 0.020 0.036 0.036 0.048 12.5 0.049 0.040 0.014 0.033 0.021 13.0 0.013 0.032 0.029 0.018 0.038 13.5 0.034 0.028 0.032 0.033 0.032 14.0 0.048 0.039 0.009 0.019 0.034 14.5 0.024 0.034 0.037 0.028 0.031 15.0 0.017 0.033 0.018 0.024 0.046 15.5 0.029 0.023 0.024 0.012 0.020 16.0 0.021 0.023 0.016 0.033 0.021 16.5 0.022 0.038 0.008 0.024 0.016 17.0 0.011 0.011 0.021 0.034 0.009 17.5 0.033 0.015 0.025 0.013 0.015 18.0 0.009 0.002 0.005 -0.005 0.011 18.5 0.018 0.011 0.012 0.016 0.012 19.0 0.013 0.027 0.004 0.011 0 .020 19.5 0.020 0.011 0.018 0.014 0.004 20.0 0.014 0.013 -0.004 0.019 0.002 Absorbance(X) - Concentration(Y) Regression Equation: Y = 5.010X + 0.219 ( r 2 = 0.996) 1 46 T a b l e E9 . Phase I I -Measured abso rbances a t V e r t i c a l Tank #1. TIME NO. OF F ISH—> 0 15 30 45 100 (min) (nm) 0 .0 0 .0 0 .0 0.0 0.0 0.0 0 .5 0 .0 0 .006 0. 122 0.014 0.019 1 .0 0 .080 0. 1 25 0.151 0 .076 0. 146 1.5 0. 1 24 0. 150 0. 1 57 0.151 0. 1 66 2.0 0. 134 0. 1 38 0. 1 38 0. 150 0. 1 48 2.5 0. 128 0. 1 49 0. 1 34 0 .142 0. 1 37 3.0 0. 1 03 0.113 0. 1 48 0.141 0. 135 3.5 0 .119 0.110 0.111 0.131 0. 1 02 4 .0 0 .090 0 .079 0. 1 02 0. 1 24 0. 103 4 .5 0 .076 0. 126 0.098 0 .133 0. 107 5.0 0 .097 0.088 0. 1 04 0 .088 0.099 5.5 0 .068 0 .069 0.060 0.082 0.096 6 .0 0 .094 0.091 0.078 0 .096 0.085 6 .5 0 .075 0.078 0.064 0.071 0.087 7.0 0 .049 0.071 0.072 0.067 0.083 7.5 0 .064 0.078 0.081 0 .089 0.064 8.0 0 .058 0.067 0.068 0 .083 0.056 8.5 0 .036 0.054 0.054 0 .056 0.062 9.0 0 .062 0.059 0.067 0 .063 0.059 9.5 0 .050 0.054 0.045 0.048 0.049 10.0 0 .042 0.037 0.052 0.032 0 .015 10.5 0 .036 0.050 0.036 0 .046 0.040 11.0 0 .034 0 .026 0.035 0.014 0.026 11 .5 0 .046 0.045 0.054 0.051 0.047 12.0 0 .023 0.031 0.036 0.052 0.041 12.5 0 .024 0 .016 0 .039 0 .023 0.008 13.0 0 .042 0.036 0.037 0.014 0.023 13 .5 0.031 0.034 0.018 0.012 0 .023 14.0 0 .029 0 .026 0.022 0.014 0 .016 14.5 0 .034 0.021 0.014 0.011 0 .026 15.0 0.011 0 .020 0.035 0.026 0 .009 15 .5 0 .024 0 .016 0.015 0.014 0 .029 16.0 0 .016 0.012 0.022 0.008 0 .016 16 .5 0 .026 0.011 0.012 0 .016 0.002 17.0 0 .014 0.007 0.011 0 .006 0.0 17.5 0 .009 0.014 0.007 0.008 -0.001 18.0 0 .008 0.002 0.023 0.007 -0 .003 18 .5 0 .002 0.007 0.004 0 .002 0.006 19.0 0 .018 0.011 0.003 0 .006 -0 .004 19 .5 0 .009 0.008 0.008 0.004 -0 .005 20 .0 0 .006 0.002 0.009 0 .002 0.004 Abso rbance (X ) - C o n c e n t r a t i o n ( Y ) R e g r e s s i o n E q u a t i o n : Y = 4.982X + 0 .095 ( r 2 = 0 .997 ) 1 47 T a b l e E10 . Phase II -Measured a b s o r b a n c e s a t V e r t i c a l Tank #2. TIME NO. OF FISH—> 0 1 5 30 45 100 (min) (nm) 0.0 0.0 0 .0 0.0 0.0 0 .0 0.5 0 .0 -0 .012 -0 .026 0 .089 0 .012 1.0 0.116 0 .116 0. 1 26 0 . 1 33 0. 106 1 .5 0 .098 0. 1 32 0. 127 0. 1 23 0. 122 2.0 0 .090 0 .113 0.116 0. 1 02 0 .127 2.5 0.088 0 .092 0.111 0. 1 05 0. 124 3.0 0.082 0 .096 0.097 0.084 0 .094 3.5 0.071 0 .074 0.086 0.091 0 .083 4 .0 0.078 0.081 0.066 0.078 0 .088 4 .5 0.071 0 .065 0.066 0.064 0 .074 5.0 0 .063 0.051 0.071 0 .059 0 .067 5.5 0.058 0 .054 0.058 0 .053 0 .059 6.0 0.057 0 .037 0.049 0.054 0 .059 6.5 0.044 0 .048 0.048 0 .049 0.071 7.0 0 .034 0.044 0.048 0.027 0 .034 7.5 0.027 0 .029 0.044 0 .046 0 .042 8.0 0 .036 0 .042 0.031 0.037 0 .044 8.5 0 .029 0.031 0.028 0.031 0 .034 9.0 0.018 0 .006 0.014 0.027 0 .023 9.5 0 .010 0 .034 0.027 0.008 0 .036 10.0 0.014 0 .022 0.011 0.018 0 .012 10.5 0 .016 0. 002 0.026 0 .005 0.011 11.0 0.014 0 .003 0.002 0.002 0 .003 11.5 -0 .003 0 .002 0.016 0.007 0 .002 12.0 0 .017 0 .009 -0 .006 0.001 0 .006 12.5 0.031 0 .005 0.007 0 .006 -0 .008 13.0 -0 .008 - 0 . 0 0 3 -0.001 0.004 0 .004 13.5 0 .006 - 0 . 0 0 6 0.001 0.003 -0 .004 14.0 -0 .009 - 0 . 0 0 6 0.008 -0 .007 -0 .008 14.5 0.004 0 .007 -0 .007 -0 .008 -0 .018 15.0 - 0 . 0 0 9 - 0 . 0 1 7 -0 .008 -0 .004 - 0 . 0 1 3 15.5 -0 .006 - 0 . 0 1 7 -0 .013 -0 .004 -0 .018 16.0 -0 .009 - 0 . 0 0 2 -0 .014 -0 .018 -0 .014 16.5 -0 .017 - 0 . 0 0 2 -0 .013 -0.011 - 0 . 0 2 3 17.0 -0.031 - 0 . 0 0 7 -0 .018 -0 .017 -0 .017 17.5 -0 .024 - 0 . 0 0 7 -0 .006 -0 .008 -0 .022 18.0 -0 .022 - 0 . 0 1 0 -0 .004 -0 .022 -0 .012 18.5 -0 .015 - 0 . 0 1 9 -0 .016 -0 .003 - 0 . 0 1 3 19.0 -0 .016 - 0 . 0 1 7 -0.021 -0 .018 -0 .014 19.5 -0 .012 -0 .024 -0.021 -0 .012 -0 .024 20 .0 -0 .012 - 0 . 0 1 0 -0 .024 - 0 . 0 0 9 -0 .018 Abso rbance (X ) - C o n c e n t r a t i o n ( Y ) R e g r e s s i o n E q u a t i o n : Y = 4.989X + 0.168 ( r 2 = 0 .997) 1 48 T a b l e E 1 1 . Phase II -Measured TIME NO. OF FISH—•> 0 (min) 0 .0 0 .0 0.5 0.0 1 .0 0.0 1 .5 0.0 2.0 0.0 2.5 0 .028 3.0 0 .043 3.5 0 .097 4 .0 0. 106 4 .5 0 .119 5.0 0 . 126 5.5 0 . 1 30 6.0 0 . 1 32 6 .5 0. 1 38 7.0 0. 142 7.5 0. 1 49 8.0 0. 130 8.5 0 . 122 9.0 0 . 108 9.5 0 .103 10.0 0. 100 10.5 0.092 11.0 0 .085 11.5 0.081 12.0 0 .076 12.5 0 .060 13.0 0 .057 13.5 0 .053 14.0 0 .049 14.5 0 .048 15.0 0 .050 15.5 0 .039 16.0 0 .035 16.5 0 .029 17.0 0 .027 17.5 0 .022 18.0 0 .019 18.5 0 .020 19.0 0.021 19.5 0.018 20 .0 0 .020 abso rbances a t Raceway #1. 15 30 45 100 (nm) 0 . 0 0 . 0 0 . 0 0 . 0 0 . 0 0 . 0 0 . 0 0 . 0 0 . 0 0 . 0 0 . 0 0 . 0 0 . 0 0 . 0 0 . 018 0. 017 0. 0 0 . 028 0. 033 0. 044 0. 032 0. 043 0. 065 0. 066 0. 063 0. 073 0. 095 0. 092 0. 109 0. 098 0. 1 1 4 0. 1 29 0. 1 1 6 0. 109 0. 129 0. 1 34 0. 1 26 0. 123 0. 1 35 0. 1 46 0. 1 34 0. 1 33 0. 141 0. 1 54 0. 1 36 0. 1 37 0. 1 42 0. 1 56 0. 1 56 0. 1 43 0. 1 42 0. 1 55 0. 1 55 0. 1 44 0. 1 45 0. 1 47 0 . 1 40 0. 147 0. 1 33 0 . 1 49 0. 1 39 0. 151 0. 1 29 0. 1 36 0. 1 45 0. 129 0. 1 35 . 0 . 1 1 6 0. 128 0. 1 26 0. 1 1 2 0. 1 1 5 0. 1 1 2 0. 1 16 0. 1 02 0. 109 0. 108 0. 1 06 0. 1 04 0. 090 0 . 1 02 0. 091 0. 082 0. 084 0. 096 0. 084 0. 084 0 . 069 0. 077 0. 071 0. 079 0. 072 0. 073 0. 071 0. 076 0. 059 0. 073 0. 059 0. 064 0. 057 0. 052 0. 064 0. 054 •0. 051 0 . 049 0. 053 0. 048 0. 046 0 . 046 0 . 047 0. 044 0. 048 0. 044 0. 042 0. 043 0. 039 0. 041 0. 038 0. 038 0 . 034 0. 024 0. 042 0. 041 0 . 041 0. 018 0. 028 0. 033 0. 027 0. 024 0. 022 0. 023 0. 039 0. 026 0. 027 0. 016 0. 034 0. 017 0. 019 0. 026 0. 017 0. 017 0. 014 0. 023 0. 016 0. 017 0. 017 0. 024 0. 026 0. 008 0. 007 0. 007 0. 026 0 . 018 - o . 004 0. 013 0. 013 0. 008 - o . 002 0. 018 0. 017 0. 012 - o . 006 0. 023 0. 015 Abso rbance (X ) - C o n c e n t r a t i o n ( Y ) R e g r e s s i o n E q u a t i o n : Y = 5.225X + 0.054 ( r 2 = 0 .995) 1 49 T a b l e E12 . Phase I I -Measured a b s o r b a n c e s a t Raceway #2. TIME NO. OF F ISH—> 0 15 30 45 100 (min) (nm) 0.0 0.0 0 .0 0 .0 0 .0 0.0 0.5 0.0 0 .0 0.0 0 .0 0.0 1 .0 0.0 0.0 0.0 0 .0 0.0 1 .5 0.0 0.0 -0 .004 0 .003 -0 .002 2.0 -0.011 -0 .002 0.018 0.018 0.021 2.5 0 .006 0.014 0 .039 0 .029 0 .066 3.0 -0 .006 0.034 0.057 0 .063 0.092 3.5 0.023- 0.066 0.071 0.094 0. 1 03 4 .0 0.088 0 .092 0.096 0. 1 02 0. 1 27 4 .5 0. 100 0. 1 22 0. 120 0. 1 32 0. 1 48 5.0 0. 1 53 0. 1 45 0. 1 22 0. 132 0.117 5.5 0. 1 59 0. 1 53 0. 1 37 0. 1 62 0. 1 55 6.0 0. 1 62 0 . 1 63 0. 1 46 0. 163 0. 144 6 .5 0. 1 75 0. 170 0. 1 54 0. 1 53 0. 1 55 7.0 0. 180 0. 155 0. 143 0. 167 0. 1 67 7.5 0 . 1 64 0 . 1 50 0. 1 46 0. 1 30 0. 139 8.0 0.161 0 . 1 42 0.113 0. 134 0.111 8.5 0. 1 43 0. 128 0. 127 0. 123 0. 125 9.0 0. 129 0. 1 25 0.112 0. 132 0.118 9.5 0 .119 0 . 1 40 0. 1 08 0. 1 08 0 .067 10.0 0 .113 0.121 0. 1 04 0. 106 0.094 10.5 0 .087 0 .110 0.068 0 .089 0 .083 11.0 0.091 0 .095 0.074 . 0 .104 0.081 11.5 0 .060 0 .082 0.073 0.087 0 .053 12.0 0.072 0 .089 0.058 0.061 0 .056 12.5 0.064 0 .070 0.054 0 .055 0.046 13.0 0 .047 0.061 0 .056 0 .059 0.041 13.5 0.037 0 .056 0 .033 0 .052 0.026 14.0 0.054 0 .049 0 .039 0 . 044 0.012 14 .5 0 .029 0 .036 0 .036 0 .016 0 .039 15.0 0 .029 0 .038 0.031 0.027 0.031 15.5 0 .020 0 .034 0 .033 0 .007 0 .015 16.0 0 .020 0 .030 0.038 0.021 0.020 16.5 0.018 0 .032 0.027 0.021 0.024 17.0 0 .014 0 .023 0 .013 0 .015 0.018 17.5 0 .016 0 .010 0.018 0.030 0 .029 18.0 0.012 0 .008 0.018 0 .015 -0 .005 18.5 0 .015 0 .015 0 .012 0.011 0.017 19.0 0 .006 0 .007 -0 .006 0 .022 0.012 19.5 0.008 -0.001 0.016 -0 .007 0 .005 20 .0 -0 .003 - 0 . 0 0 6 0 .003 0.007 0.001 Abso rbance (X ) - C o n c e n t r a t i o n ( Y ) R e g r e s s i o n E q u a t i o n : Y = 5.378X + 0.136 ( r 2 = 0 .990) 1 50 T a b l e E 1 3 . Phase I l l - M e a s u r e d abso rbances a t C i r c u l a r Tank #1. TIME NO. OF F ISH—> 0 (min) 0 .0 0.0 0 .5 0 .068 .1 .0 0.094 1 .5 0 . 1 29 2.0 0. 1 32 2.5 0. 1 28 3.0 0. 1 25 3.5 0.131 4 .0 0. 1 09 4 .5 0 .114 5.0 0. 1 07 5.5 0.091 6.0 0.076 6 .5 0.082 7.0 0 .099 7.5 0 .074 8.0 0.082 8.5 0 .077 9.0 0 .076 9.5 0.052 10.0 0.064 10 .5 0.062 11.0 0.062 11.5 0 .049 12.0 0.047 1.2.5 0.052 13.0 0 .048 13 .5 0.038 14.0 0 .038 14 .5 0 .036 1 5.0 0.052 15 .5 0.034 16.0 0 .053 16 .5 0 .030 17.0 0.022 17.5 0.031 18.0 0 .025 18 .5 0 .017 19.0 0 .026 19.5 0.032 20 .0 0.022 15 30 45 100 (nm) 0 . 0 0 . 0 0 . 0 0. 0 0 . 1 34 0. 1 43 0. 1 40 0. 159 0 . 153 0. 1 62 0. 1 58 0. 181 0. 1 49 0. 1 52 0. 1 52 0. 1 49 0 . 1 46 0 . 1 44 0. 1 48 0. 161 0 . 1 37 0. 1 48 0. 1 34 0. 1 52 0. 1 27 0. 1 26 0. 1 27 0. 1 44 0. 1 36 0. 1 07 0. 1 24 0. 1 28 0 . 1 1 4 0. 1 24 0. 1 02 0. 1 36 0 . 1 1 4 0. 1 27 0. 1 07 0. 1 18 0. 1 24 0. 096 0. 098 0. 108 0. 098 0. 1 1 1 0. 089 0. 102 0 . 086 0. 1 02 0. 081 0. 096 0. 092 0. 1 1 1 0. 082 0. 086 0 . 082 0. 086 0. 086 0. 084 0 . 090 0. 077 0. 084 0. 076 0. 082 0. 087 0. 066 0. 054 0. 079 0. 078 0. 072 0. 077 0. 076 0. 076 0. 078 0. 068 0. 081 0. 067 0. 067 0. 046 0. 076 0. 061 0. 071 0. 052 0. 054 0. 055 0. 056 0. 046 0. 059 0 . 063 0. 051 0. 054 0. 069 0. 057 0. 057 0. 061 0. 058 0. 052 0. 058 0. 052 0 . 040 0. 058 0. 042 0. 048 0 . 051 0. 052 0. 047 0. 043 0. 037 0. 023 0. 042 0. 036 0. 042 0. 043 0. 032 0. 027 0 . 063 0. 054 0. 052 0 . 032 0. 031 0. 041 0. 036 0. 025 0. 023 0. 039 0. 029 0. 038 0. 026 0. 048 0. 040 0. 033 0 . 026 0. 024 0. 023 0. 032 0. 036 0. 040 0. 034 0. 018 0. 029 0. 027 0. 034 0. 013 0. 013 0. 026 0. 032 0. 027 0 . 031 0. 032 0. 027 0. 016 0. 016 0. 027 0. 037 0. 029 0. 026 0. 017 0. 032 0. 019 0. 019 0. 028 0. 036 0. 023 Abso rbance (X ) - C o n c e n t r a t i o n ( Y ) R e g r e s s i o n E q u a t i o n : Y = 5.837X - 0 .070 ( r 2 = 0 .994 ) 151 T a b l e E14. Phase 111-Measured abso rbances a t C i r c u l a r Tank #2. TIME NO. OF FISH—> 0 (min) 0 .0 * 0 .0 0.5 0 .092 1.0 0.121 1.5 0 . 1 30 2.0 0 .119 2.5 0 .122 3.0 0 .122 3.5 0 .113 4 .0 0.111 4 .5 0 .096 5.0 0 .104 5.5 0 .099 6.0 0 .093 6 .5 0 .084 7.0 0 .078 7.5 0.081 8.0 0 .069 8.5 0 .064 9.0 0 .068 9.5 0 .063 10.0 0 .056 10 .5 0 .058 11.0 0 .049 11 .5 . 0 .049 12.0 0.051 12 .5 0 .043 13 .0 0 .050 13 .5 0 .039 14.0 0.041 14 .5 0 .038 15 .0 0 .033 15 .5 0 .037 16.0 0 .024 16 .5 0 .030 17.0 0 .036 17 .5 0.031 18 .0 0 .027 18 .5 0.031 19.0 0 .025 19 .5 0 .018 20 .0 0 .024 15 30 45 100 (nm) 0. 0 0 . 0 0 . 0 0 . 0 0 . 1 27 0. 1 30 0. 1 58 0. 167 0. 149 0. 1 59 0. 159 0. 176 0. 1 53 0. 1 66 0. 1 62 0. 178 0. 1 46 0. 1 43 0 . 1 45 0. 158 0. 1 34 0. 141 0. 1 37 0. 154 0. 101 0. 1 30 0. 1 29 0. 134 0. 1 23 0. 1 27 0 . 1 04 0. 1 26 0. 1 19 0. 1 20 0. 1 23 0. 1 1 7 0. 105 0. 1 04 0. 1 1 3 0. 1 1 1 0. 1 10 0. 1 10 0. 108 0. 096 0. 087 0. 1 02 0 . 094 0. 092 0. 082 0. 097 0. 096 0. 089 0. 094 0. 087 0. 1 03 0. 091 0. 087 0. 093 0. 094 0. 087 0. 071 0. 082 0. 081 0. 077 0 . 082 0. 067 0. 083 0. 071 0. 068 0. 072 0. 081 0. 046 0. 067 0. 067 0 . 069 0. 056 0. 060 0. 068 0. 069 0. 054 0. 068 0. 062 0. 051 0. 054 0. 062 0. 056 0. 058 0. 053 0. 032 0. 047 0. 049 • 0. 048 0, 052 0. 051 0. 057 0. 047 0. 044 0. 043 0. 047 0. 047 0. 044 0. 049 0. 046 0. 032 0. 044 0. 052 0. 042 0. 029 0. 042 0. 034 0. 029 0. 041 0. 033 0. 043 0. 041 0. 036 0. 038 0. 037 0. 042 0. 029 0. 034 0. 044 0. 037 0. 017 0. 038 0. 020 0. 041 0. 029 0. 038 0. 032 0 . 039 0. 030 0. 033 0. 033 0 . 032 0. 032 0. 032 0. 031 0 . 027 0. 023 0. 027 0. 027 0. 031 0. 022 0. 028 0. 026 0. 032 0. 026 0. 023 0. 029 0. 027 0. 026 0. 029 0. 024 0 . 029 0. 024 0. 017 0. 023 0. 022 0. 026 0. 025 0. 016 0. 024 0. 017 A b s o r b a n c e ( X ) - C o n c e n t r a t i o n ( Y ) R e g r e s s i o n E q u a t i o n : Y = 5 . 8 0 8 X - 0 . 0 8 7 ( r 2 = 0 . 9 9 9 ) 1 52 T a b l e E 1 5 . Phase I l l - M e a s u r e d a b s o r b a n c e s a t V e r t i c a l Tank #1. TIME NO. OF F ISH—> 0 1 5 30 45 1 00 (min) (nm) 0 .0 0.0 0.0 0.0 0.0 0.0 0.5 0 .004 0.074 0.082 0.067 0. 126 1 .0 0.031 0. 1 56 0. 1 73 0 .113 0. 186 1 .5 0 . 172 0.161 0.161 0 . 1 66 0. 174 2.0 0. 134 0. 165 0. 1 64 0 . 179 0. 172 2.5 0. 1 58 0. 1 46 0.161 0 . 167 0. 1 26 3.0 0 .112 0. 1 46 0.1 08 0. 154 0. 1 32 3.5 0 .113 0. 1 43 0.151 0. 1 44 0. 1 44 4 .0 0 .103 0.131 0. 1 32 0 .145 0. 138 4 .5 0. 103 0. 1 27 0.121 0 . 120 0.119 5.0 0 .086 0. 1 26 0. 1 22 0 . 122 0.118 5.5 0 .112 0.121 0.097 0 .114 0.113 6.0 0.111 0 .115 0.097 0 .112 0.099 6 .5 0 .093 0.078 0.091 0.101 0.093 7.0 0 .076 0.087 0.091 0 .090 0.091 7.5 0 .086 0 .069 0.092 0 .083 0.089 8 .0 0 .087 0 .075 0.090 0 .079 0.081 8.5 0 .066 0.072 • 0.074 0 .077 0.072 9.0 0 .062 0.072 0.069 0 .083 0.070 9.5 0 .075 0.072 0.061 0.077 0.069 10.0 0 .078 0 .063 0.057 0.064 0.053 10.5 0.061 0.064 0.061 0.054 0.056 11.0 0 .053 0.068 0.061 0.061 0.049 11 .5 0 .053 0 .056 0.052 0 .052 0.047 12.0 0 .058 0 .043 0.048 0 .044 0.042 12 .5 0 .052 0.044 0.049 0.051 0.043 13.0 0 .048 0.052 0.047 0 .049 0.041 13 .5 0 .034 0 .046 0.041 0 .036 0.036 14.0 0.031 0.037 0.038 0 .036 0.033 14 .5 0 .042 0.034 0.036 0 .042 0.027 15.0 0 .027 0.027 0.036 0.031 0.030 15.5 0 .036 0 .033 0.032 0 .043 0.028 16.0 0 .029 0.028 0.027 0 .029 0.021 16 .5 0 .028 0.034 0 .036 0 .036 0.031 17.0 0 .025 0 .029 0.022 0.034 0.038 17 .5 0 .024 0 .028 0.031 0 .023 0.026 18.0 0.031 0 .026 0.021 0 .028 0.023 18 .5 0 .022 0.028 0.027 0.028 0.019 19.0 0 .018 0.021 0.022 0.027 0.021 19 .5 0 .023 0.021 0.020 0 .026 0.024 20 .0 0 .014 0.018 0.021 0 .023 0.021 Abso rbance (X ) - C o n c e n t r a t i o n ( Y ) R e g r e s s i o n E q u a t i o n : Y = 5.714X - 0.074 ( r 2 = 0 .997) 153 T a b l e E16 . Phase I l l - M e a s u r e d a b s o r b a n c e s a t V e r t i c a l Tank #2. TIME NO. OF F ISH—> 0 (min) 0 .0 0.0 0 .5 0 .300 1 .0 0 . 148 1.5 0 . 1 46 2.0 0. 1 56 2.5 0. 1 37 3.0 0 .118 3.5 0 . 1 26 4 .0 0 .118 4 .5 0 .093 5.0 0 . 104 5.5 0.101 6 .0 0 .089 6 .5 0 .099 7.0 0 .069 7.5 0 .073 8.0 0 .078 8.5 0 .056 9 .0 0.061 9.5 0 .069 10.0 0.062 10.5 0 .058 11.0 0 .066 11.5 0 .055 12.0 0 .050 12.5 0 .049 13.0 0 .045 13 .5 0.052 14.0 0 .045 14.5 0 .044 15.0 0 .040 15 .5 0.038 16.0 0 .038 16 .5 0 .036 17.0 0 .037 17 .5 0 .035 18.0 0 .034 18.5 0 .035 19.0 0 .032 19 .5 0 .030 20 .0 0 .032 15 30 45 100 (nm) 0 . 0 0. 0 0 . 0 0. 0 0 . 273 0. 1 73 0 . 189 0. 152 0. 193 0. 1 87 0 . 1 92 0. 207 0. 1 62 0. 182 0 . 195 0. 202 0. 1 48 0. 1 67 0 . 1 72 0. 196 0. 151 0. 1 73 0 . 171 0. 173 0. 1 37 0. 1 38 0 . 1 52 0. 164 0. 1 34 0. 1 50 0 . 141 0. 1 67 0. 114 0. 127 0 . 1 32 0. 136 0. 1 1 4 0. 1 1 4 0 . 1 29 0. 1 18 0. 103 0. 1 1 4 0 . 1 23 0. 1 39 0. 106 0. 102 0 . 097 0. 1 1 7 0. 101 0. 100 0 . 1 1 6 0. 097 0. 097 0. 1 04 0 . 1 1 3 0. 1 1 7 0. 1 02 0. 091 0 . 1 08 0. 1 03 0. 082 0. 090 0 . 093 0. 078 0. 078 0. 097 0 . 1 06 0. 073 0. 074 0. 076 0 . 097 0. 090 0. 074 0. 085 0 . 075 0. 066 0. 068 0. 070 0 . 082 0. 064 0. 062 0. 072 0 . 070 0. 060 0. 067 0. 064 0 . 072 0. 055 0. 061 0. 049 0 . 053 0. 052 0. 060 0. 063 0 . 052 0. 059 0. 054 0. 057 0 . 057 0. 056 0. 056 0. 059 0 . 059 0. 037 0. 051 0. 054 0 . 060 0. 043 0. 052 0. 040 0 . 052 0. 044 0. 047 0. 069 0 . 059 0. 051 0. 048 0. 048 0 . 048 0. 033 0. 050 0. 039 0 . 042 0. 031 0. 038 0. 048 0 . 042 0. 030 0. 043 0. 035 0 . 034 0. 018 0. 038 0. 042 0 . 036 0. 031 0. 040 0. 038 0 . 034 0. 034 0. 035 0. 032 0 . 038 0. 031 0. 030 0. 028 0 . 033 0. 036 0. 033 0. 027 0 . 034 0. 023 0. 033 0. 037 0 . 033 0. 024 0. 030 0. 032 0 . 021 0. 029 0. 029 0. 032 0 . 023 0. 027 Abso rbance (X ) - C o n c e n t r a t i o n ( Y ) R e g r e s s i o n E q u a t i o n : Y = 5.711X - 0 .088 ( r 2 = 0 .999) 154 T a b l e E17 . Phase 111-Measured a b s o r b a n c e s a t Raceway #1. TIME NO. OF FISH—> 0 15 30 45 100 (min) (nm) 0.0 0.0 0 .0 0.0 0 .0 0.0 0 .5 0 .0 0 .0 0.0 0.0 0 .0 1 .0 0 .0 0 .0 0.0 0 .0 0 .0 1 .5 0 .0 0 .0 0.042 0.052 0 .098 2.0 0.0 0 .038 0.062 0.057 0. 107 2.5 0 .018 0.078 0. 1 02 0.093 0. 1 27 3.0 0 .047 0.097 0. 1 07 0. 129 0. 157 3.5 0.091 0 . 109 0. 1 47 0.161 0. 1 62 4 .0 0 . 102 0. 1 23 0. 1 62 0. 167 0 . 186 4 .5 0. 1 36 0. 1 27 0. 1 57 0 . 187 0 . 187 5.0 0. 1 54 0.133 0. 1 72 0 . 189 0.172 5.5 0. 182 0. 127 0. 1 59 0 . 1 55 0 .169 6.0 0. 162 0. 1 42 0. 1 63 0. 1 92 0.171 6 .5 0. 162 0 . 147 0.144 0.167 0 . 1 59 7.0 0. 1 59 0. 1 38 0. 1 70 0.171 0 . 162 7.5 0. 1 48 0. 169 0. 1 44 0 . 1 66 0 . 1 54 8.0 0. 147 0. 1 48 0. 1 38 0. 1 47 0. 1 38 8.5 0. 132 0. 1 26 0. 1 46 0. 1 27 0 . 126 9.0 0. 127 0. 1 27 0. 1 27 0.112 0 . 1 07 9.5 0 .105 0 . 1 32 0.113 0 . 122 0 . 1 07 10.0 0 .096 0.111 0.131 0. 1 00 0 .080 10.5 0 .094 0. 1 03 0.112 0.089 0.081 11.0 0.091 0.091 0.097 0.097 0.084 11.5 0 .073 0 .089 0.091 0.101 0 .073 12.0 0 .079 0.084 0.082 0.093 0 .056 12.5 0 .067 0.081 0.073 0.072 0.081 13.0 0.051 0 .082 0.076 0.072 0 .062 13.5 0.054 0.078 0.062 0 .069 0 .057 14.0 0 .049 0 .078 0.068 0.068 0.064 14.5 0.042 0 .064 0.071 0.058 0.041 15.0 0 .033 0 .076 0.043 0 .036 0.034 15.5 0 .044 0 .048 0.061 0.052 0 .029 16.0 0 .028 0 .042 0.056 0.029 0.034 16.5 0 .037 0.034 0.041 0 .053 0.024 17.0 0 .033 0 .056 0.036 0.034 0 .037 17.5 0 .024 0 .055 0.038 0.034 0 .028 18.0 0 .027 0.047 0.023 0 .043 0 .023 18.5 0 .018 0 .045 0.022 0.027 0 .026 19.0 0.027 0.051 0.051 0.038 0 .027 19.5 0 .016 0 .043 0.034 0.027 0.021 20 .0 0 .017 0.028 0.039 0.044 0.021 Abso rbance (X ) - C o n c e n t r a t i o n ( Y ) R e g r e s s i o n E q u a t i o n : Y = 5.849X - 0 .075 ( r 2 = 0 .999) 155 T a b l e E18 . Phase 111-Measured a b s o r b a n c e s a t Raceway #2. TIME NO. OF F ISH—> 0 15 30 45 100 (min) (nm) 0 .0 0 .0 0 .0 0.0 0.0 0.0 0 .5 0 .0 0 .0 0.0 0.0 0 .0 1 .0 0 .0 0 .0 0.0 0.0 0 .012 1 .5 0.0 0 .0 0.0 0 .028 0 .036 2.0 0.0 0 .032 0.038 0.074 0 .079 2.5 0 .019 0 .047 0.058 0.082 0. 1 23 3.0 0 .036 0 .073 0.101 0 .119 0. 1 42 3.5 0 .046 0 .112 0.114 0. 1 44 0. 1 66 4 .0 0. 1 06 0. 1 28 0.141 0. 147 0. 181 4 .5 0. 129 0 .134 0. 144 0. 1 57 0 . 1 58 5.0 0. 144 0. 1 62 0. 1 48 0. 1 49 0.191 5.5 . 0 .194 0. 1 52 0. 1 66 0. 1 72 0. 1 66 6.0 0. 182 0. 1 53 0. 1 64 0. 1 62 0.172 6 .5 0. 1 58 0.161 0. 157 0.161 0.171 7.0 0. 1 55 0 . 1 56 0.161 0. 1 56 0 . 1 57 7.5 0. 1 53 0. 1 62 0.151 0. 1 37 0 . 1 52 8.0 0. 152 0. 129 0. 147 0. 1 38 0. 1 44 8.5 0. 145 0. 1 28 0.131 0. 1 27 0. 1 32 9.0 0. 1 37 0 .137 0.118 0. 1 25 0.103 9.5 0. 1 28 0 .113 0.112 0.112 0 .103 10.0 0. 109 0 .112 0 .095 0. 1 09 0.087 10.5 0. 1 04 0.091 0. 1 08 0.098 0 .086 11.0 0 .099 0 .098 0.098 0.084 0.067 11 .5 0 .086 0 .092 0.087 0.092 0.077 12.0 0 .084 0.071 0.092 0 .099 0.058 12.5 0.064 0 .077 0.078 0 .056 0.058 13.0 0 .068 0 .070 0.064 0.052 0.057 13 .5 0.061 0 .062 0.052 0.052 0.037 14.0 0 .059 0.061 0.045 0.052 0.051 14 .5 0 .042 0 .052 0.041 0.052 0 .049 15 .0 0 .049 0 .059 0 .056 0.038 0.034 15.5 0 .043 0 .052 0.051 0.037 0.024 16.0 0.041 0 .042 0.042 0.036 0.051 16 .5 0 .047 0 .033 0.031 0.040 0.032 17.0 0.041 0 .039 0.033 0.040 0 .026 17 .5 0 .026 0 .032 0.037 0 .033 0 .013 18.0 0.032 0 .024 0.037 0 .053 0 .023 18.5 0 .026 0 .036 0.048 0.048 0.012 19 .0 0 .039 0 .022 0.033 0 .036 0 .019 19 .5 0 .014 0 .033 0.032 0.042 0.033 20 .0 0.021 0 .018 0.022 0.028 0.018 Abso rbance (X ) - C o n c e n t r a t i o n ( Y ) R e g r e s s i o n E q u a t i o n : Y = 5.609X - 0.066 ( r 2 = 0 .999) 156 APPENDIX G - SCALING CONSIDERATIONS D imens i ons f o r s c a l e d - u p t a n k s w i t h n a t u r a l s c a l e f a c t o r s of 5, 7 . 5 , and 10 a r e p r e s e n t e d b e l o w . The s c a l i n g i s based on F r o u d e ' s Law, t h u s , n e g l e c t i n g the e f f e c t of the f i s h , the d i r e c t i o n of f l o w and r e l a t i v e v e l o c i t i e s obse r ved i n the t e s t t a n k s w i l l be m a i n t a i n e d i n the b i g g e r t a n k s . In d e t e r m i n i n g the b iomass of f i s h t h a t can be s u s t a i n e d i n the b i g g e r t a n k s , i t i s s u g g e s t e d t h a t the pond l o a d i n g index (PL I ) method ( K l o n t z e t . a l . , 1978) w i l l be a d o p t e d . For examp le , a t a water t e m p e r a t u r e of 15°C and a s i t e e l e v a t i o n of 305 m, the t a b u l a t e d Wi i s 1.01 grams per l i t e r of r e a r i n g space pe r c e n t i m e t e r o f body l e n g t h pe r wate r t u r n o v e r pe r h o u r . W i t h a t a r g e t f i s h s i z e of 30 cm, the c a l c u l a t e d a l l o w a b l e b iomass i s 1400 kg f o r the tank w i t h a s c a l e f a c t o r of 7 . 5 . T h i s l o a d i n g w i l l g i v e a s t o c k i n g d e n s i t y of 70.71 kg/m 3 and a c a r r y i n g c a p a c i t y of 1.82 k g / l / m i n . The c a l c u l a t e d P i p e r ' s F of 60.61 gram per c e n t i m e t e r of f i s h l e n g t h per l i t e r per m inu te of f l o w i s a p p r o x i m a t e l y e q u a l t o the t a b u l a t e d F of 6 0 . 4 4 . Note t h a t w i t h a s c a l e f a c t o r of 7 . 5 , the p r o t o t y p e of the v e r t i c a l u n i t s has d i m e n s i o n s a l m o s t s i m i l a r t o t hose of the t e s t s i l o of B u s s , e t . a l . ( 1 9 7 0 ) . A l s o , t h a t the water dep ths i n the p r o t o t y p e c i r c u l a r tank and raceway a re o n l y a few c e n t i m e t e r s deeper than the s t a n d a r d . However , i t i s c a l c u l a t e d t h a t the water s u r f a c e v e l o c i t i e s i n the c i r c u l a r t a n k s w i l l be f rom 27 t o 82 cm/sec . F i s h s m a l l e r t han 18 cm w i l l f i n d i t h a r d t o w i t h s t a n d the maximum e x p e c t e d v e l o c i t y . To get a round t h i s , the d i s c h a r g e has t o be d e c r e a s e d w i t h a c o r r e s p o n d i n g r e d u c t i o n i n l o a d i n g d e n s i t i e s . In so d o i n g , F r o u d e ' s number i s b e i n g r e p l a c e d w i t h v e l o c i t y as the c r i t e r i o n f o r s c a l e up . D iamete r L e n g t h Water X - s e c t i o n a l (m) (m) Depth A rea (m) (m 2 ) S c a l e F a c t o r = 5 [ V o l = 5.9 m \ Q = •  280 1/min] C i r c u l a r 3.00 - 0.84 7.00 V e r t i c a l 1 .50 - 3.50 1 .68 Raceway 1 .00 9.00 0.82 0 .65 S c a l e F a c t o r = 7.5 [ V o l = 19. 8 m 3 , Q = 770 1/min] C i r c u l a r 4 .50 - 1 .26 1 5.75 V e r t i c a l 2 .25 - 5.25 3.77 Raceway 1 .50 13.50 1 .22 1 .46 S c a l e F a c t o r = 10 [ V o l = 4 7 . 0 m 3 , Q = 1581 1/min] C i r c u l a r 6 .00 - 1 .68 28 .00 V e r t i c a l 3.00 - 7.00 6 .70 Raceway 2.00 18.00 1 .63 2.60 

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