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The production of planktonic herbivorous food chains in large-scale continuous cultures Brown, Penelope Stevenson 1979

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THE PRODUCTION OF PLANKTONIC HERBIVOROUS FOOD CHAINS IN LARGE-SCALE CONTINUOUS CULTURES by PENELOPE STEVENSON BROWN B.Sc, University of V i c t o r i a , 1971 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY in THE FACULTY OF GRADUATE STUDIES (Department of Zoology, I n s t i t u t e of Oceanography) He accept t h i s thesis as conforming to the,required standard THE UNIVERSITY OF BRITISH COLUMBIA August,1979 (c) Penelope Stevenson Brosn,1979 I n p r e s e n t i n g t h i s t h e s i s i n p a r t i a l f u l f i l m e n t o f t h e r e q u i r e m e n t s f o r a n a d v a n c e d d e g r e e a t t h e U n i v e r s i t y o f B r i t i s h C o l u m b i a , I a g r e e that t h e L i b r a r y s h a l l m a k e 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 a n d s t u d y . I f u r t h e r a g r e e t h a t p e r m i s s i o n f o r e x t e n s i v e c o p y i n g o f t h i s t h e s i s f o r s c h o l a r l y p u r p o s e s may b e g r a n t e d b y t h e H e a d o f my D e p a r t m e n t o r by h i s r e p r e s e n t a t i v e s . I t i s u n d e r s t o o d t h a t c o p y i n g o r p u b l i c a t i o n o f t h i s t h e s i s f o r f i n a n c i a l g a i n s h a l l n o t b e a l l o w e d w i t h o u t my w r i t t e n p e r m i s s i o n . _ , Zoology D e p a r t m e n t o f T h e U n i v e r s i t y o f B r i t i s h C o l u m b i a 2075 Wesbrook Place Vancouver, Canada V6T 1W5 D a t e October 10th, 1979 A B S T S A C T Besearch S u p e r v i s o r : P r o f . I.E. Earsons The production of p l a n k t o n i c herbivorous food c h a i n s was examined i n l a r g e s c a l e continuous c u l t u r e s u s i n g a deep n u t r i e n t - r i c h source of seawater t o promote high p r o d u c t i v i t y r a t e s . Both t u r b u l e n t and non-turbulent u p v e i l i n g systems were i n v e s t i g a t e d i n one-stage c u l t u r e experiments with f l u s h i n g r a t e s r a n g i n g from 0.25/day to 0.7 5/day. The systems were analyzed i n terms of the dynamics of the primary community and t h e i r s u i t a b i l i t y f o r the growth and s u r v i v a l of two b i v a l v e m o l l u s c s , o y s t e r s ( C r a s s o s t r e a qigas ) and s c a l l o p s ( Chlamys ha s t a t a h e r i c i a ). The r e s u l t s i n d i c a t e d t h a t a high f l u s h i n g r a t e of the continuous c u l t u r e system (0.75/day) was r e q u i r e d f o r the growth of the s c a l l o p s under n a t u r a l f o r c i n g c o n d i t i o n s . Maximum r a t e s of 16.8$ per month sere achieved at a depth of one metre, due t o a reduced l i g h t i n t e n s i t y and temperature at t h i s depth compared with s u r f a c e c c n d i t o n s . In c o n t r a s t , the one-stage c u l t u r e system with a f l u s h i n g r a t e of 0.25/day provided s u i t a b l e environmental c o n d i t i o n s f o r the growth of ;oysters, although an experimental comparison of two s t o c k i n g d e n s i t i e s i n d i c a t e d that the phytoplankton c o n c e n t r a t i o n l i m i t e d the growth of C r a s s o s t r e a q i g a s a t d e n s i t i e s below commercial l e v e l s . In the two-stage c u l t u r e experiments, the dynamics of the of the primary communities were monitored at c o n s t a n t and v a r i a b l e f l u s h i n g r a t e s , ranging from 0.10/day to 1.00/day, i n t u r b u l e n t upwelling systems with n a t u r a l f o r c i n g c o n d i t i o n s . The dynamics of the primary community were p r e d i c t e d with r e a s o n a b l e i i i a ccuracy u s i n g a numerical s i m u l a t i o n model with e x p e r i m e n t a l l y determined parameters and values of the f o r c i n g v a r i a b l e s . The growth of the o y s t e r s was a l s o examined as a f u n c t i o n of t h e i r s i z e , t h e i r d e n s i t y and v a r i o u s primary communities as a food source, The r e s u l t s i n d i c a t e d t h a t a primary system with a f l u s h i n g r a t e of 1.0/day provided the most s u i t a b l e environmental c o n d i t i o n s f o r the production of o y s t e r s . . The maximum growth r a t e s a t t a i n e d d u r i n g the experiment (18%/«eek) were g r e a t e r than r a t e s measured i n an 'optimal' f i e l d l o c a t i o n i n B r i t i s h Columbia. i v TABLE OF CONTESTS CHAPTER 1. INTRODUCTION ................................... 1 CHAPTER 2. EXPERIMENTAL FACILITIES AND METHODOLOGY ........ 9 Experimental F a c i l i t i e s ................................ 9 One-stage C u l t u r e Experiment Hit h Constant F o r c i n g Conditions.•»..•••...•»•.«••!»••.•»...••••.•••.••««»••• 10 One-stage C u l t u r e Experiments With N a t u r a l F o r c i n g -Con d i t i o ns ...'«....«...«••..»....«....... .....*..«•...*., 10 Two-stage C u l t u r e Experiments With N a t u r a l F o r c i n g C o n d i t i o n s ..•.......,............•..•.•.*..»..*.. ...11 13 e t .no do.lo g y ........ m •'•.•....••..•..••••••..•......••••.•*,... • . 12. P h y s i c a l Parameters: L i g h t , Temperature And S a l i n i t y . . 12 N u t r i e n t Parameters •. ..... ............ ..... ..... ... • .- 1 4 Primary Parameters: Standing Stock, Primary P r o d u c t i v i t y and Community S t r u c t u r e ................ 15 Secondary P r o d u c t i v i t y ...........................•-» • , 18 Experiment 1 ............ ........................... , 18 Ex p e r i m en t 2 A ......w..*.-*,............... ...:.....*.. . 18 E x per x m en t 2B ........................*........ «w ... . 19 E xper i BI en t 3ft ...........................*..««*««.«. 20 Experiment 3B ........................ •..... , .20 Experiment 5 ....................................... 20 CHAPTER 3. ONE-STAGE CONTINUOUS CULTURES IK NGN-TURBULENT UPWELLING SYSTEMS WITH CONSTANT FOBC.ING CONDITIONS ...... ,22 Dynamics Of The Primary Communities .................... 22 P h y s i c a l Environment ...........<•...... ........ ....... 23 N u t r i e n t C o n d i t i o n s ................................... 23 Phytoplankton Dynamics ............................... 25 Standing Stock . . . . . . . . . . . . . . . . . . 2 5 Primary P r o d u c t i v i t y ............................... 26 Phytoplankton Stock Composition.................. ... 27 Growth And S u r v i v a l Of, The S c a l l o p P o p u l a t i o n .......... 28 CHAPTER 4. ONE-STAGE CONTINUOUS CULTUBES IN NGN-TURBULENT UP»ELXIHG SYSTEMS WITH NATUfiAL FORCING CONDITIONS ........ 30 Comparison Of Two Herbivorous Food Chains At A Low F l u s hing R ate ............ .... ••..»•..»•»».•»... . ... » .. «• ». .•. ,-, 31 Dynamics Of The Primary Communities ...».....,....,..-.. ,32 P h y s i c a l Environment ... .*».....»•. .. ..."...*.,........... 32 N u t r i e n t C o n d i t i o n s .................................. 33 Ehytcplankton Dynamics ............................... 34 Stan din g Stoc Jc .»..».>..,. ........................ . 35 .Oxygen 'Levels ........................................ 36 Primary P r o d u c t i v i t y .......... ... . 37 Composition Of The Phytoplankton Community ........... 38 Growth Of The fleriiivores, C r a s s o s t r e a gigas , During Growth Of The H e r b i v o r e s , Chlamys h a s t a t a h e r i c i a , During EXP2B ........................................ 40 V F u r t h e r I n v e s t i g a t i o n Of The Oyster Food Chain At An Increased-. Her b i v o r e Densit y • . ,., ..............,.. . . . 41 Dynamics Of The Primary Community ...................... 41 P h y s i c a l Environment ................................. ,41 N u t r i e n t Begime . ............................... ....... ,42 Phytoplankton Dynamics ............................... .42 Standing Stock ...... » . . . . . . . . . . . . . . . . . . . . . . . . . . . .42 Oxygen L e v e l s ..................................... 43 Primary P r o d u c t i v i t y ................w............;, 44 Composition Of The Phytoplankton Community ......... 44 Growth of the O y s t e r s a t a Higher S t o c k i n g Density .....,45 F u r t h e r I n v e s t i g a t i o n Of The S c a l l o p Food Chain At An Increased F l u s h i n g Bate Of The System ............... 46 Dynamics Of The Primary Community ...................... 46 P h y s i c a l Environment .- ... • . . . . . . . i ,.,.«.>.,, . 46 Nut r i e n t Begime ...................................... ,47 Phytoplankton Dynamics ............................... .47 S tan d i n g St oc k ...'..-..«.,.....<....*•. • ......... ....... ,-47 Oxygen L e v e l s ....... . ...»...»......'....-. ., 48 Primary P r o d u c t i v i t y ........................ ....... ,49 Composition Of The Phytoplanktcn Community .........49 Growth Of The S c a l l o p s At a Higher F l u s h i n g Bate .......,49 CHAPTER 5. TBO-STAGE CONTINUOUS COLTUBES*IB TURBULENT UPWELLING SYSTEMS: DYNAMICS OF THE PSIMARY COMMUNITIES AT TWO COMPARATIVE FLUSHING BATES ........................... ,51 Dynamics Of The Primary Communities At Two Comparative F l u s h i n g Bates .....», .......«.'......-.... ,52 P h y s i c a l Environment ................................. 52 Nut r i e n t Regime .......................................53 Phytoplankton Dynamics .... ....... .................... .54 Standxng Sitock .••..••••.•••.••...................». 54 Pigment R a t i o s ...... .......... .... 56 Oxygen Leve l s ...................................... 56 Primary P r o d u c t i v i t y ............................... 58 Es t i m a t i o n Of Parameters For A Primary P r o d u c t i v i t y Model .... ........................... .61 Composition Of The P h y t c p l a r k t o n Community ......... 63 CHAPTER 6. 3HO-STAGE CONTINUOUS COLTUBES OF I1ANKTONIC HEBBIVOJOUS FOOD CHAINS: DYNAMICS OF TJTE PEIMABY COMMUNITIES AT VARIABLE FLUSHING BATES ...................................65 Dynamics Of The Primary Communities At V a r i a b l e F l u s h i n g Bates During The Experimental Period ................ 66 P h y s i c a l Environment ................................. 67 Nut r i e n t Begime ...................................... 68 Phytoplankton Dynamics ............................... 70 Standing Stock ..................................... 70 Pigment B a t i o s ...................................... 71 Oxygen L e v e l s ...................................... 72 Primary P r o d u c t i v i t y ............................... 73 Es t i m a t i o n Of Parameters For A Primary P r o d u c t i v i t y Model ...... ........... ........................... ,76 Composition Of The Phytoplankton Community ......... 77 v i CHAPTER 7. TWO—ST AGE CONTINUOUS CULTURES OF PLANKTGN.IC HERBIVOROUS FOOD CHAINS: GROWTH OF THE HEBE.IVORES ........ 80 Experimental Design .................................... ,80 Experimental R e s u l t s ................................... 81 Environmental C o n d i t i o n s During The Oyster Growth ; Experiments ............................»»......*....,81 Oyster Growth As A Function Of The Experimental F a c t o r s ............................................. 85 CHAPTER 8. ANALYSIS OF THE RESULTS USING A SIMULATION MO DE L . ., .v. . . . ......... .......................... . - 89 Es t i m a t i o n Of The P h y s i o l o g i c a l Parameters During The Continuous C u l t u r e s ........................... 89 Sim u l a t i o n Of The Phytoplankton Dynamics .,....,.,.,.-,.92 D e s c r i p t i o n Of The Model . . . . . . . . . . . . . . . . . , 9 2 S i m u l a t i o n R e s u l t s . . . . . . . . . . . . . . . . . . . . w . . , 9 5 CHAPTER 9. COMPARATIVE DISCUSSION OF THE EXPERIMENTAL RESULTS ......99 CHAPTER 10. SUMMARY AND CONCLUSIONS 107 T ABLES «. ......... ...,110 FIGURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ,149 BIBLIOGRAPHY . ,. , i , . . . . v . . . . . .. . . , , . , 253 APPENDICES . ..........v.'..,.,-,...-... ,260 vxx LIST OF TABLES Table 1. Belevant c u l t u r e s t u d i e s of marine production p.110 Table 2. D e s c r i p t i v e s t a t i s t i c s f o r Experiment 2A p..111. Table 3. D e s c r i p t i v e s t a t i s t i c s f o r Experiment. 2B p. 112 Table 4. Oyster growth during Experiment 2A P-113 Table 5. S c a l l o p growth during Experiment 2.B p. 114 Table 6. D e s c r i p t i v e s t a t i s t i c s f o r Experiment 3A p.115 Table 7. Oyster growth during Experiment 3A p. 116 Table 8. D e s c r i p t i v e s t a t i s t i c s f o r Experiment 3B p.117 Table 9., S c a l l o p growth during Experiment 3B p.118 Table 10. C o r r e l a t i o n between f o r c i n g v a r i a b l e s d u r i n g EXP4 p.119 Table 11.. D e s c r i p t i v e s t a t i s t i c s f o r Experiment 4A p. 120 Table 12. D e s c r i p t i v e s t a t i s t i c s f o r Experiment 4B P«122 Ta b l e 13. A n a l y s i s of varia n c e d u r i n g Experiment 4A p. 124 Table 14. A n a l y s i s of variance d u r i n g Experiment 4B p.126 Table 15. P r o d u c t i v i t y component a n a l y s i s f o r E x p e r i m e n t s p. 128 Table 16. Design f o r the two-stage c u l t u r e experiments p.129 Table 17. N u t r i e n t enrichment experiment r e s u l t s p.130 Table 18. D e s c r i p t i v e s t a t i s t i c s f o r Experiment 5A p. 131 Table 19. D e s c r i p t i v e s t a t i s t i c s f o r Experiment 5B p.132 Table 20. A n a l y s i s of variance d u r i n g Experiment 5A p.133 Table 21. A n a l y s i s o f varia n c e d u r i n g Experiment 5B p.135 Taijle 22. P r o d u c t i v i t y r e s u l t s d u r i n g Experiment 5 p. 137 Table 23. P r o d u c t i v i t y component a n a l y s i s f o r Experiment 5 p.138 Table 24. Environmental c o n d i t i o n s i n the her x i v o r e tanks p.139 Table 25. Growth of o y s t e r s i n the two-stage c u l t u r e p.140 Table 26. Growth of o y s t e r s as a f u n c t i o n of FJJP, SIZE and DENS i n the two-stage c u l t u r e p. 143 Table 27. Non - l i n e a r LSF of the *P versus I* data f o r the TANH and SMITH models p.144 v i i i LIST OF FIGUBES F i g u r e 1. , Experimental f a c i l i t i e s f o r Experiment 1. p.149 F i g u r e 2.< D u p l i c a t e tank systems f o r Experiments 2 and 3, p.150 F i g u r e 3. Experimental f a c i l i t i e s f o r Experiments 2 and 3. p.151 F i g u r e 4., Experimental f a c i l i t i e s f o r E x p e r i m e n t s . , p. 152 F i g u r e 5. Two-stage c u l t u r e systems f o r Experiment 5. p.153 F i g u r e 6, N i t r a t e c o n c e n t r a t i o n during Experiment 1A. P-154 F i g u r e 7. N i t r a t e c o n c e n t r a t i o n d u r i n g Experiment LB. p.155 F i g u r e 8. Phytoplankton stock during Experiment 1A. p.156 F i g u r e 9., Phytoplankton stock during Experiment IB. P-157 F i g u r e .10. ., Primary p r o d u c t i v i t y d u r i n g Experiment 1A., p.158 F i g u r e 11., Primary p r o d u c t i v i t y during Experiment LB. p.159 F i g u r e 12. Primary p r o d u c t i v i t y ( s t a n d a r d i z e d ) during Experiment 1B p. 160 F i g u r e 13. . S o l a r r a d i a t i o n d u r i n g Experiment 2., p.161 F i g u r e 14., Temperature during Experiment 2A. p.162 F i g u r e 15., Temperature dur i n g Experiment 2E. , p.163 F i g u r e 16. N i t r a t e c o n c e n t r a t i o n during Experiment 2A. P-164 F i g u r e 17. N i t r a t e c o n c e n t r a t i o n during Experiment 2B. P-165 F i g u r e 18. Phytoplankton stock during Experiment 2A. , p.166 F i g u r e 19. Phytoplankton stock during Experiment 2B. p.167 F i g u r e 20. Oxygen c o n c e n t r a t i o n during Experiment 2A. p.168 F i g u r e 21. Oxygen c o n c e n t r a t i o n d u r i n g Experiment 2B. p.169 F i g u r e 22. Primary p r o d u c t i v i t y during Experiment 2A., p.170 F i g u r e 23. Primary p r o d u c t i v i t y during Experiment 2B. p.171 Fi g u r e 24. Primary p r o d u c t i v i t y (standardized) during Experiment 2A. p. 172 F i g u r e 25. Primary p r o d u c t i v i t y (standardized) d u r i n g Experiment 2B. p.173 F i g u r e 26. S o l a r r a d i a t i o n d u r i n g Experiment 3A. p.174 F i g u r e 27. Temperature during Experiment 3A. , p.175 F i g u r e 28. N i t r a t e c o n c e n t r a t i o n during Experiment 3A. , p. 176 F i g u r e 29. Phytoplankton stock d u r i n g Experiment 3A. P-177 F i g u r e 30. Oxygen c o n c e n t r a t i o n during Experiment 3A. p.178 F i g u r e 31. Primary p r o d u c t i v i t y during Experiment 3A. p.179 F i g u r e 32. Primary p r o d u c t i v i t y (standardized) during Experiment 3A. , p. 180 F i g u r e 33. S o l a r r a d i a t i o n d u r i n g Experiment 3B. p. 181 F i g u r e 34. , Temperature during Experiment 3£. p.182 F i g u r e 35., N i t r a t e c o n c e n t r a t i o n during Experiment 3B., P-183 F i g u r e 36. Phytoplankton stock during Experiment 3B. p.184 F i g u r e 37. Oxygen c o n c e n t r a t i o n during Experiment 3B., p.185 F i g u r e 38. , Primary p r o d u c t i v i t y during Experiment 3B. p.186 F i g u r e 39. Primary p r o d u c t i v i t y (standardized) d u r i n g Experiment 3B. ; p. 187 F i g u r e 40.. F o r c i n g c o n d i t i o n s d u r i n g Experiment 4 p.188 F i g u r e 41. Temperature during Experiment 4., p. 189 F i g u r e 42. N i t r a t e c o n c e n t r a t i o n during Experiment 4. p.190 F i g u r e 4 3. Phytoplankton stock during Experiment 4.. P-191 F i g u r e 44., CHLB:CHLA r a t i o d u r i n g Experiment 4. p.192 F i g u r e 45. Carotenoid:CHLA r a t i o during Experiment 4., p.193 F i g u r e 46. , Oxygen c o n c e n t r a t i o n during Experiment 4. p.194 F i g u r e 47. Gross primary p r o d u c t i v i t y during Experiment 4. p.195 F i g u r e 48. E e s p i r a t i o n r a t e d u r i n g Experiment 4. p.196 F i g u r e 49. Net primary p r o d u c t i v i t y during Experiment 4. p.197 i x F i g u r e 50. Net primary p r o d u c t i v i t y ( d a i l y ) during Experiment 4. p.198 F i g u r e 51. Gross primary p r o d u c t i v i t y ( d a i l y ) during Experiment,4. p.199 F i g u r e 52. Gross primary p r o d u c t i v i t y (standardized) during Experiment 4. p.200 F i g u r e 53. Net primary p r o d u c t i v i t y (standardized) during Experiment 4. p. 201 F i g u r e 5 4. R e s p i r a t i o n r a t e (standardized) diiring E x p e r i m e n t s . p. 202 F i g u r e 55. , Estimates of ALPHAC during Experiment 4 p. 203 F i g u r e 56. „ E s t i m a t e s o f ALPHAG during Experiment 4. p.204 F i g u r e 57. C o u l t e r counts on Day 6 of Experiment 4A. , p. 205 F i g u r e 58. , C o u l t e r counts on Day 9 of Experiment 4A. , p.206 F i g u r e 59. C o u l t e r counts on Day 15 of Experiment 4A. p.207 F i g u r e 60., C o u l t e r counts on Day 21 cf Experiment 4A. p.208 F i g u r e 61., C o u l t e r counts on Day 27 c f Experiment 4 A. p. 209 F i g u r e 62., F o r c i n g c o n d i t i o n s d u r i n g Experiment 5. p.210 Fi g u r e 63. Temperature during Experiment 5. p.211 F i g u r e 64., N i t r a t e c o n c e n t r a t i o n during Experiment 5. p.212 F i g u r e 65. Phytoplankton stock during Experiment 5. p.213 F i g u r e 66. CHL£A:CBLA r a t i o during Experiment 5., P»214 F i g u r e 67. CarotenoidiCHLA r a t i o during Experiment 5. p.215 F i g u r e 68. Oxygen c o n c e n t r a t i o n during Experiment 5., P-216 F i g u r e 69. Gross primary p r o d u c t i v i t y during Experiment 5 P-217 F i g u r e 70. Gross primary p r o d u c t i v i t y ( d a i l y ) during Experiment 5 p.218 Fi g u r e 71. B e s p i r a t i o n r a t e d u r i n g Experiment 5 P-219 F i g u r e 72. Net primary p r o d u c t i v i t y d u r i n g Experiment 5 p.220 F i g u r e 7 3. Net primary p r o d u c t i v i t y ( d a i l y ) during Experiment 5 P»221 F i g u r e 74. Gross primary p r o d u c t i v i t y (standardized) during Experiment 5 p.222 F i g u r e 75. B e s p i r a t i o n r a t e (standardized) during Experiment 5 P* 223 F i g u r e 76. Net primary p r o d u c t i v i t y (standardized) during Experiment 5 p.224 Fi g u r e 77. Esti m a t e s o f ALPHAC during Experiment 5 p.225 F i g u r e 78. Estimates of ALPHAG during Experiment 5 p.226 F i g u r e 79. C o u l t e r counts on Day 6 of Experiment 5A. p.227 F i g u r e 80. C o u l t e r counts on Day 9 of Experiment 5A. p. 228 F i g u r e 81. C o u l t e r counts on Day 21 of Experiment 5A. p.229 F i g u r e 82. C o u l t e r counts on Day 24 of Experiment 5A. p.230 F i g u r e 83. , C o u l t e r counts on Day 36 of Experiment 5A. p.231 F i g u r e 84. C o u l t e r counts on Day 39 c f Experiment 5A. p. 232 F i g u r e 85.. C o u l t e r counts on Day 6 of Experiment 5B. p.233 F i g u r e 86. C o u l t e r counts on Day 9 of Experiment 5B. p. 234 F i g u r e 87. C o u l t e r counts on Day 21 of Experiment 5B. p.235 F i g u r e 88. C o u l t e r counts on Day 24 cf Experiment 5B. p.236 Fi g u r e 89. C o u l t e r counts on Day 36 cf Experiment 5B. p. 237 Figu r e , 9 0 . C o u l t e r counts on Day 39 of Experiment 5B. p.238 F i g u r e 91. Temperature i n two-stage o y s t e r c u l t u r e s p.239 Fi g u r e 92. C h l o r o p h y l l a i n two-stage o y s t e r c u l t u r e s p.240 F i g u r e 93. Oxygen l e v e l s i n two-stage o y s t e r c u l t u r e s p.241 X F i g u r e 94. Growth of o y s t e r s as a f u n c t i o n of DENS i n the two-stage c u l t u r e p.242 F i g u r e 9 5. Growth of o y s t e r s as a f u n c t i o n of SIZE i n the two-stage c u l t u r e P-243 F i g u r e 96. 'P v e r s u s ' I * curves as a f u n c t i o n of TEMP and N03 p,244 F i g u r e 97, Simulated phytoplankton stock d u r i n g Experiment 5B: Bun 1 P-245 F i g u r e 98, . Simulated phytoplankton stock d u r i n g Experiment 5B: Run 2 p.246 F i g u r e 99. Simulated phytoplankton stock d u r i n g Experiment 5B: Bun 3 p.247 F i g u r e 100. Simulated phytoplankton stock d u r i n g Experiment 5E: Sun 4 p.248 F i g u r e 101. Simulated phytoplankton stock d u r i n g Experiment 5A: Bun 1 p. 249 Figu r e 102. Simulated phytoplankton stock d u r i n g Experiment 5&: Bun 2 p. 250 F i g u r e 103; Simulated phytoplankton stock d u r i n g Experiment 5B: Bun 1 with GRAZE p.251 P l a t e I . , Herbivore tanks i n two-stage experiments p.252 P l a t e I I . A r t i f i c i a l c u l t c h i n two-stage experiments p.252 x i ACKNOWLEDGEMENT I would l i k e to acknowledge, with thanks, the s u j p c r t and a s s i s t a n c e of irany people, who c o n t r i b u t e d to the c o o p l e t i c c of t h i s study. I would a l s o l i k e t o acknowledge the N a t i o n a l Research C o u n c i l c f Canada f o r p r o v i d i n g f i u a r c i a l s u p j e r t with Post-Graduate S c h o l a r s h i p s . I would f i r s t l i k e t o thank my s u p e r v i s o r , Dr. I.E. Pars ens, f o r h i s i n s p i r a t i o n i n the i n i t i a t i o n of t h i s r e s e a r c h , c r i t i c i s m of i t s design and f i n a n c i a l support f o r the experimental o p e r a t i o n s , i n c l u d i n g the i n v a l u a b l e a s s i s t a n c e cf B i l l L i during the cne-stage c u l t u r e experiments, and Angela Norton and C a r c l e Eawden of the I n s t i t u t e c f Oceanography, U.B.C., f o r a n a l y s i s of n u t r i e n t samples. Many other people at the I n s t i t u t e were a l s o most h e l p f u l , I would a l s o l i k e to acknowledge the c o - o p e r a t i o n of the F i s h e r i e s and Marine S e r v i c e , Department of the E i v i r c n a e n t , f o r p r o v i d i n g experimental f a c i l i t i e s at the P a c i f i c Envirornsent I n s t i t u t e , West Vancouver, and i n p a r t i c u l a r , thack the many s c i e n t i s t s and t e c h n i c i a n s vhc provided valued s c i e n t i f i c ard moral support while the experiments were being conducted. I am a l s c most g r a t e f u l to Dr. J . i . C . Tonslinscn, F a c u l t y of Commerce and Business A d m i n i s t r a t i o n , U.B.C, f o r h e l p f u l d i s c u s s i o n s cn systems r e s e a r c h , and to C S . C , s i H i e f o r her expert advice i n the design of a computer data rase and i n the a n a l y s i s of the data. F i n a l l y , I would l i k e to thank my committee f o r h e l p f u l d i s c i s s i o n s during t h i s study: Dr. I.E. P a r s e r s , Dr. A.G. L e s i s , and Dr. F.J..B. T a y l o r of the I n s t i t u t e of Oceanography; Dr. T.H. Carefoot o f the Department of Zoology; and Dr. D.K. Farmer of the I n s t i t u t e c f Ocean Sc i e n c e s , P a t r i c i a Eay, E r i t i s h Columbia. 1 CHAPTER 1., INTRODUCTION Maximizing o r g a n i c production i n a q u a t i c ecosystems i s an e s s e n t i a l component of e f f e c t i v e f i s h e r i e s management (Paloheimo and D i c k i e , 1970; S a i l a , 1971), aguaculture development ( P i l l a y , 1970), and e u t r o p h i c a t i c n c o n t r o l (Di Toro e t a l . , 1975; Bierman e t a l . , 1974). O b s e r v a t i o n s of h i g h l y p r o d u c t i v e ecosystems, such as areas of up w e l l i n g (Cushing, 1971) and e s t u a r i n e environments ( T e a l , 1962; Odum and S c h l e s k e , 1961; Byther, 1969), i n d i c a t e the importance of time: and space v a r i a b l e s i n determining both the production and o r g a n i z a t i o n o f primary, secondary, and t e r t i a r y communities. E x t e n s i v e s t u d i e s o f these ecosystems using f i e l d experiments and ex p l a n a t o r y m u l t i d i m e n s i o n a l models have d e s c r i b e d with v a r y i n g complexity the production and o r g a n i z a t i o n o f that p a r t i c u l a r food c h a i n or web, e x e m p l i f i e d by i a l s h and Dugdale (1971), Wiegert e t a l . (1973) and Caper on (1973) r e s p e c t i v e l y . However at t h i s complex l e v e l of i n t e r a c t i o n s , with inherent n c n - l i n e a r i t i e s , ecosystem responses t o n a t u r a l or a r t i f i c i a l p e r t u r b a t i o n s are l e s s p r e d i c t a b l e , p a r t i c u l a r l y i f parameter values f o r the o r i g i n a l model; a r e e s t i m a t e d or borrowed frcm the l i t e r a t u r e ( S a i l a , 1973) Two complementary r e s e a r c h approaches t o improve t h i s s i t u a t i o n a r e , f i r s t , t o reduce the complexity and c o n n e c t i v i t y o f the n a t u r a l ecosystem by i n i t i a l l y »subsystemizing* on a t r o p h i c b a s i s , and secondly, to i n v e s t i g a t e c o n t r o l l e d ecosystems, with known f o r c i n g c o n d i t i o n s using time and space as c o n t r o l parameters., In the f i r s t c ase f o r example, a n a l y s i s 2 o f phytoplaivk t o n i c subsystems i n c l u d e s t u d i e s of n a t u r a l l y e a t r o p h i c environments which emphasize production (Patten and Van Dyne, 1 9 6 8 ; Winter e t a i , ; , 1975; Smayda, 1973) and o r g a n i z a t i o n ( P i a t t and Subba Hao, 1970; M c A l l i s t e r s t a l . , , 1 9 7 2 ) , seme r e l a t i n g s p e c i f i c a l l y t o time, expressed as the f l u s h i n g r a t e of the system (Dickman, 1969; C a s s i n and McLaughlin, 1 9 7 1 ) , or t o space ( P i a t t , 1972)•• In the second case, •;• c o n t r o l l e d experiments of organic production have v a r i e d i n o p e r a t i o n a l s c a l e , number of t r o p h i c l e v e l s , and o p e r a t i o n a l c o n t r o l i n terms of time and space, as o u t l i n e d l a t e r i n t h i s c hapter. C o n d i t i o n s f o r maximizing p r o d u c t i o n a t the primary l e v e l have been proposed by S t e e l e and Menzel (1962), Steeman N i e l s e n ( 1 9 6 2 ) , and Takahashi and Parsons (1972) by f o c u s i n g on the importance o f s p a t i a l c o n s i d e r a t i o n s such as t u r b u l e n t mixing and the depth of the water column,. In a d d i t i o n t o these f i e l d and c o n t r o l l e d experiments, more t h e o r e t i c a l approaches to p r o d u c t i o n and o r g a n i z a t i o n of p l a n k t c n i c systems have been c o n s i d e r e d by B e l l a (1970), Grenney e t a l . (1973a), Grenney e t a l . (1973b), Boss (1973), P i a t t £t a l . , (1977) f o r phytoplankton and by P h i l l i p s (1974), S t e e l e (1974), and S t e e l e and M u l l i n (1977) f o r higher t r o p h i c l e v e l s . The importance of the f l u s h i n g r a t e and of s p a t i a l c o n s i d e r a t i o n s i n determining the production and s t r u c t u r e o f marine ecosystems, provided the b a s i s f o r the present r e s e a r c h s t r a t e g y t o examine pr o d u c t i o n i n p l a n k t o n i c systems.. The h y p o t h e s i s was t h a t production i n b i v a l v e feed c h a i n s c o u l d be enhanced by using a deep n u t r i e n t - r i c h source of seawater and an o p t i m a l f l a s h i n g r a t e and s p a t i a l s t r u c t u r e cf the ecosystem to maximize p r o d u c t i v i t y . In o r d e r to t e s t t h i s h y p o t h e s i s , d u p l i c a t e c o n t r o l l e d ecosystems were designed with the f o l l o w i n g o p e r a t i o n a l c a p a b i l i t i e s : 1. a l a r g e continuous c u l t u r e tank system i n which the f l u s h i n g r a t e c o u l d be' v a r i e d and c o n t r o l l e d , and the seairater e i t h e r upwelled with a minimum o f t u r b u l e n c e or a r t i f i c i a l l y mixed. 2. a deep n u t r i e n t - r i c h source of seawater to enhance primary p r o d u c t i v i t y . 3. a r e l a t i v e l y shallow water column (about 1 metre) t o minimize l i g h t l i m i t a t i o n o f .the primary community. 4. a c h o i c e between c o n t r o l l e d , constant f o r c i n g c o n d i t i o n s of l i g h t and temperature; t o s i m p l i f y the system response, or, n a t u r a l l y f l u c t u a t i n g environmental c o n d i t i o n s to simulate p r o d u c t i o n i n the f i e l d . 5. / u t i l i z a t i o n o f the production s y s t e i i as a one-stage c u l t u r e by p l a c i n g the h e r b i v o r e s i n s i t u , o r expansion t o a two-stage c u l t u r e system, with the primary p r o d u c t i o n tank f e e d i n g i n t o a s e t of h e r b i v o r e t a n k s . Using t h i s c o n t r o l l e d system, the o b j e c t i v e s of the r e s e a r c h were e s s e n t i a l l y t w o - f o l d . The f i r s t o b j e c t i v e was t o examine the production and o r g a n i z a t i o n of a n a t u r a l p h y t o p l a n k t o n i c community at v a r i o u s f l u s h i n g r a t e s i n t u r b u l e n t u p w e l l i n g systems f o r a s i g n i f i c a n t p e r i o d of time (greater than one month) , and t o analyze n u m e r i c a l l y the ecosystem responses with a d e t e r m i n i s t i c mathematical model using s i m u l a t i o n t e c h n i q u e s . . The f l u s h i n g r a t e s ranged from 0.10 day-1 to 1.0 4 day-1 d u r i n g the experiments s i n c e the growth of phytoplankton i s enhanced at these r a t e s (Brown and Parsons, 1972) and they r e p r e s e n t a t t a i n a b l e flows f o r s m a l l m a r i c u l t u r e impoundments., The second o b j e c t i v e was to examine the r e s u l t i n g growth o f the h e r b i v o r e p o p u l a t i o n s i n both one-stage and two-stage c u l t u r e s . P o p u l a t i o n s of o y s t e r s ( C r a s s o s t r e a gigas ) , i n the form of commercial c u l t c h 1 , and s c a l l o p s ( Chlamys h a s t a t a h e r i c l a ) which were co n f i n e d i n net cages, were p o s i t i o n e d a t s p e c i f i c s u b s t a t i o n s and depths i n the primary production tanks. T h e i r growth and e f f e c t on the primary community was monitored d u r i n g the one-stage c u l t u r e experiments.. B i v a l v e s were chosen as the experimental h e r b i v o r e s s i n c e they produce a commercially h a r v e s t a b l e resource at a low, e c o l o g i c a l l y e f f i c i e n t l e v e l i n the food c h a i n . , Furthermore, the s p a t i a l h e t e r o g e n e i t y of the h e r b i v o r e s c o u l d be e x p e r i m e n t a l l y c o n t r o l l e d . In the two-stage c u l t u r e experiment, growth of j u v e n i l e C r a s s c s t r e a gigas were examined u s i n g a r t i f i c i a l l y c o n s t r u c t e d c u l t c h (with e i g h t o y s t e r s per c u l t c h ) , designed to simulate the c u l t c h used i n commercial p r o d u c t i o n . The p r o d u c t i o n of ycung o y s t e r s could then be determined a s a f u n c t i o n of the f o l l o w i n g f a c t o r s : s i z e of the o y s t e r s , d e n s i t y of the o y s t e r s , and f l u s h i n g r a t e of the system. The dynamics of the temperature, s t a n d i n g s t o c k of phytoplankton, oxygen, ammonia and urea i n the h e r b i v o r e tanks, were analyzed as c o v a r i a t e s . , Examples of s t u d i e s p e r t i n e n t to t h i s r e s e a r c h , which * A l a r g e o y s t e r h a l f ^ s h e l l with o y s t e r s p a t attached to i t , f o r s t r i n g i n g frcm r a f t s . „ 5 b a s i c a l l y i n c l u d e s p r o d u c t i v e marine p l a n k t e n i c ecosystems, are c a t e g o r i z e d i n Table I with the f o l l o w i n g o b s e r v a t i o n s . F i r s t , there have keen few marine ecosystems which have been e x p e r i m e n t a l l y c o n t r o l l e d a t a l a r g e - s c a l e f i e l d l e v e l . , One example, however* i s the 7 50 acre t i d a l impoundment of the Lummi Indian T r i b a l E n t e r p r i s e . .. This m a r i c u l t u r e system r e l i e s on the n a t u r a l s u r f a c e plankton as the food supply f o r r e a r i n g molluscs and a supplement to the commercial d i e t s f o r r a i s i n g s a l a o u i d s . A marine impoundment u t i l i z i n g deep n u t r i e n t - r i c h seawater ( S h i e l s and Hood, 1970) c o u l d be even more b e n e f i c i a l by enhancing p r o d u c t i v i t y , and reducing high s u r f a c e temperatures and b a c t e r i a l l e v e l s . Secondly, nine l a r g e s c a l e experiments are notable i n t h e i r v a r i a b i l i t y of t r o p h i c a n a l y s i s and o p e r a t i o n a l c o a t r o l i n time and space. Of the f o u r continuous c u l t u r e s t u d i e s , two (Baab e t a l . , 1973; Halone e t a l . , 1975) u t i l i z e d n u t r i e n t - r i c h seawater from depth and were conducted i n a s e m i - t r o p i c a l environment, with average experimental temperatures g r e a t e r than ca. 25 °C . The Malone study i s of l i m i t e d value with only a f o u r day e x p e r i m e n t a l d u r a t i o n and a phytoplariktcn p o p u l a t i o n ( Chaetoceros ) which i s probably a sub-optimal h e r b i v o r e d i e t due to i t s morphology. The Baab stu d y , which concentrated on the mollusc p o p u l a t i o n s , determined t h a t t h e i r c o n t r o l l e d ecosystem favoured the growth of O s t r e a e d u l i s r a t h e r than C r a s s o s t r e a s p e c i e s . ft p r e l i m i n a r y experiment to the present r e s e a r c h (Brown a»d Parsons, 1972) examined simulated u p w e l l i n g a t v a r i o u s f l u s h i n g r a t e s of n u t r i e n t - r i c h seawater and the e f f e c t on the maximization and s t a b i l i t y of primary communities. 6 T h i r d l y , an o r g a n i c source of n u t r i e n t s , d i l a t e d sewage, has been used i n a s e r i e s of medium-scale continuous c u l t u r e s i n v e s t i g a t e d by Dunstan and Tenore, and provides a u s e f u l s p e c i a l i z e d system f o r e u t r o p h i c a t i o n c o n t r o l and m a r i c u l t u r e p r o d u c t i o n . F o u r t h l y , f i v e s m a l l - s c a l e continuous c u l t u r e s t u d i e s are i n c l u d e d as examples of c o n t r o l l e d experiments which provide i n s i g h t s i n t o maximizing production » , although they are l i m i t e d i n s c a l e f o r a p p l i c a t i o n s to mass c u l t u r e p r o d u c t i o n i n h a t c h e r i e s . I n plankton r e s e a r c h , continuous c u l t u r e techniques have been a p p l i e d mostly on a s m a l l - s c a l e t o e l u c i d a t e p h y s i o l o g i c a l p r i n c i p l e s o f n u t r i e n t , temperature and l i g h t l i m i t a t i o n , e i t h e r i n a t u r b i d o s t a t (Eppley and Dyer, 1965; Maddux and Jones, 1964) or i n a chemostat ( Caperon, 1967; Eppley e t a l . , , 1 9 7 1 ; Caperon and Myer, 1972; Davis e t a l . 1973; H a r r i s o n e t a l . , , 1976; Davis, 1976; Conway, 1977). F i n a l l y , two of t h e s m a l l - s c a l e s t u d i e s i n Table I have u t i l i z e d a raceway f o r o p e r a t i o n a l c o n t r o l ( i a l k e r and Zahradnik, 1976; Kirby-Smith and Barber, 1974), although i n terms of o p t i m i z a t i o n , t h i s system has the disadvantage of p r o v i d i n g only a r e a l or two-dimensional p r o d u c t i o n . . T a b l e I i s not intended a s a complete l i s t i n g of f i e l d o r l a b o r a t o r y s t u d i e s on the growth of marine p h y t o p l a n k t o n . or b i v a l v e molluscs, the h e r b i v o r e s used i n t h i s r e s e a r c h . , What Table I re p r e s e n t s i s a sample of s t u d i e s which. have » f o r a d i s c u s s i o n o f the continuous c u l t u r e technique, see T a y l o r (1960) and Oppenheimer (1S66). 7 e x p e r i m e n t a l l y acknowledged the s i g n i f i c a n c e of e i t h e r the s c a l e of o p e r a t i o n , t r o p h i c l e v e l c r time and space as c o n t r o l parameters, or more u s u a l l y , a combination of these f a c t o r s , i n the o r g a n i z a t i o n and production of phytoplankton and p l a n k t o n i c h e r b i v o r e s . , Other i n v e s t i g a t i o n s t c improve p r o d u c t i o n of b i v a l v e s have ranged from breeding and c o l l e c t i o n of seed (Loosanoff and Davis, 1963; Imai, 1967), t c r e a r i n g b i v a l v e s using r a f t s (Quayle, 1969,1971) and t r a y s (Parsons, 1974) to i n c r e a s e ; production i n the n a t u r a l environment. Some have concentrated on p h y s i o l o g i c a l f a c t o r s which a f f e c t the growth of b i v a l v e s , i n c l u d i n g s t u d i e s by Walne (1972), Snra and Baggaley (1976), and i c e d i n g experiments by Tenoie and Dunstan (1973b,c) and Halne (1970) which i n d i c a t e the importance of the type of the p h y t o p l a n k t e r s , as w e l l as the r e l a t i o n s h i p between the uptake r a t e a t v a r i o u s c o n c e n t r a t i o n s of phytoplankton. The r e s e a r c h presented i n t h i s d i s s e r t a t i o n has been s t r u c t u r e d t o provide comparisons between non-turbulent and t u r b u l e n t continuous c u l t u r e s i n e i t h e r a one-stage or two-stage system, a t v a r i o u s f l u s h i n g r a t e s of the system. Fi v e continuous c u l t u r e experiments, ranging from three to t e n weeks d u r a t i o n , were conducted d u r i n g t h i s study. The f o r c i n g c o n d i t i o n s of l i g h t , temperature and n u t r i e n t s were e s s e n t i a l l y c o nstant during Experiment 1. Experiments 2 to 5 were conducted i n outdoor continuous c u l t u r e systems i n order t o examine the e f f e c t o f more n a t u r a l c o n d i t i o n s of l i g h t and temperature on pr o d u c t i o n i n • p l a n k t o n i c 1 food c h a i n s . * The term p l a n k t o n i c i s used throughout t h i s study to i n c o r p o r a t e the f a c t that the experimental b i v a l v e s were suspended i n the water column and f e d on the phytoplankton., 8 In Experiment 1 (Chapter 3 ) , d u p l i c a t e n c n - t u r b u l e n t u p w e l l i n g systems were used to examine the dynamics o f a n a t u r a l phytoplankton community and the r e s u l t i n g growth of an i n s i t u p o p u l a t i o n of s c a l l o p s , at a f l u s h i n g r a t e of 0.5 d a y 1 . ., In Experiment*^ 2 and 3 (Chapter 4) , the one-stage p r o d u c t i o n of both o y s t e r and s c a l l o p food c h a i n s was examined i n a t u r b u l e n t u p w e l l i n g system. , Chapter 5 presents t h e r e s u l t s and d i s c u s s i o n o f Experiment 4, an a n a l y s i s of the dynamics of primary communities a t two comparative f l u s h i n g r a t e s (0.50 dayr* and 1.00 day—* ) . The experimental design «as expanded i n Experiment 5 t o i n c l u d e an examination of v a r i a b l e f l u s h i n g r a t e s of the primary system d u r i n g the experimental period (Chapter 6 ) , and the s u i t a b i l i t y of the r e s u l t i n g phytoplankton communities as a food source f o r the two-stage c u l t u r e of o y s t e r s (Chapter 7). An a n a l y s i s of the dynamics of the primary community, using a s i m u l a t i o n model, i s presented i n Chapter 8., Chapter 9 provides a comparative d i s c u s s i o n of the r e s u l t s of the f i v e experiments, and the c o n c l u s i o n s from t h e study are summarized i n Chapter 10., 9 CHAPTER 2. EXPERIMENTAL FACILITIES ANE METHODOLOGY Experimental f a c i l i t i e s A l l continuous c u l t u r e experiments were conducted using l a r g e tank f a c i l i t i e s a t the P a c i f i c Environment I n s t i t u t e , West Vancouver, B.C. The incoming seawater f o r the experimental system was pumped from a depth o f c a . 60 f e e t i n E n g l i s h Bay, passed through a 5 micron f i l t e r and provided a source of c o o l , nut r i e n t - r r i c h seawater ( 11 PC , 20 uM n i t r a t e l - * ) t o the pr o d u c t i o n system r e s e v o i r . The flow r a t e from the seawater r e s e v o i r to the experimental tanks was expressed as the f l u s h i n g r a t e (FH), determined by the flow rate r e q u i r e d t o r e p l a c e the t o t a l volume of the experimental tank i n one day; t h a t i s FR ( d a y * ) = v V~* ; where v=flow r a t e (1 d a y - 1 ) and V=tank volume (1). The f l u s h i n g r a t e remained r e l a t i v e l y c o n s t a n t dur i n g the experiments by u s i n g a g r a v i t y - f e e d method from the r e s e v o i r , with the flow c o n t r o l l e d by i n - l i n e v a l v e s . F l u s h i n g r a t e s up t o 1.0 day-* could be a t t a i n e d u s i n g t h i s method. A l l m a t e r i a l s used i n the system were ' i n e r t * , i n c l u d i n g the f i b r e g l a s s r e s e v o i r s and experimental t a n k s , 1/2 M PVC& 1 p i p i n g and f i t t i n g s , and p l e x i g l a s s and tygon samplers. * S denotes a r e g i s t e r e d trademark. 10 One-stage C u l t u r e Experiment with. Constant F o r c i n g C o n d i t i o n s The i n d o o r f a c i l i t i e s f o r Experiment 1 are i l l u s t r a t e d i n F i g u r e 1, i n c l u d i n g s u r f a c e and s i d e views of the experimental t a n k s . / These d u p l i c a t e production tanks had a volume o f 720 l i t r e s and the depth of the water column was 0.8 metres. The u p w e l l i n g r a t e of 0.4 m/day was c o n s t a n t over the whole area of the tank hy u s i n g a rectangular-shaped i n f l o w pipe with s m a l l h o l e s every 5 cm a p a r t . I n - s i t u samplers were l o c a t e d i n both tanks a t the s u r f a c e , mid and bottom depths at h a l f the d i s t a n c e from the end of the tank to the c e n t r a l l y l o c a t e d l e v e l l i n g p i p e . ; One-stage C u l t u r e Experiments with N a t u r a l F o r c i n g C o n d i t i o n s fts i l l u s t r a t e d i n F i g u r e s 2 and 3, d u p l i c a t e tank systems (A an B) were set up on an outdoor p l a t f o r m f o r Experiments 2 and 3. Each c o n s i s t e d of a covered seawater r e s e v o i r (3200 1 volume) which g r a v i t y - f e d t o a l a r g e production tank (3.0 m diameter, c a . 7500 1 volume).. The i n f l o w pipe near the bottom of the p r o d u c t i o n tank was angled towards the c e n t r e of the tank, and the water flow was d i r e c t e d p e r p e n d i c u l a r l y upward a t h a l f the d i s t a n c e (0.75 m) to the sampling tube, as shown i n F i g u r e 3 f o r Tank a., The i n f l o w i n g seawater t o the production tank was sampled from the r e s e v o i r o u t f l o * osing a tygon-tubing s i p h o n . In s i t u samplers 1 were l o c a t e d a t three »stations* i n 1 Three long p i e c e s of blackened tygcn t u b i n g were i n s e r t e d i n t o a PVC standpipe and used as s i p h o n s . 1 1 the c e n t e r of the production tank: s u r f a c e (0.05m), mid (0.5m) and bottom (1.0m). The t o t a l depth of the water column was 1.1 m.. The seawater outflow from the s u r f a c e of the p r o d u c t i o n tank was sampled u s i n g a T - j o i n t with a reduced tygon f i t t i n g . The p r o d u c t i o n tanks were covered with a t h i n (1/8") sheet o f p l e x i g l a s s t o reduce a e r i a l contamination and p h o t o - i n h i b i t i o n . Twelve s u b s t a t i o n s were e s t a b l i s h e d i n each p r o d u c t i o n tank f o r l o c a t i o n o f the h e r b i v o r e s d u r i n g Experiment 2 and 3, as i l l u s t r a t e d i n F i g u r e 2 f o r Tank B. Tank A was used t o examine the growth of the P a c i f i c o y s t e r , C r a s s o s t r e a giqas , and commercial c u l t c h were strung at s u r f a c e , mid and bottom depths per s u b s t a t i o n . The other e x p e r i m e n t a l h e r b i v o r e s , Chlamys  h a s t a t a .faerieia • • ( s c a l l o p s ) , were c o n f i n e d to r e c t a n g u l a r net cages, c o n s t r u c t e d with a p l e x i g l a s s frame ( ca. 30cm X 20cm X4cm ) and h e r r i n g seine net. These cages were suspended h o r i z o n t a l l y a t the s u r f a c e , mid or bottom depths i n Tank B d u r i n g Experiments 2 and 3. . Two-stage C u l t u r e Experiments with N a t u r a l F o r c i n g C o n d i t i o n s The experimental f a c i l i t i e s f o r Experiments 4 and 5 are i l l u s t r a t e d i n F i g u r e s 4 and 5. . The primary p r o d u c t i o n tanks were i d e n t i c a l t o the one-stage c u l t u r e system, except there were no h e r b i v o r e s i n s i t u and t u r b u l e n t d i f f u s i o n was a c t i v e l y produced i n both Tanks A and B by u s i n g submersible pumps. Outflow from e i t h e r primary tank c o u l d be fed i n t o the s m a l l e r h e r b i v o r e : tanks (170 l i t r e s ) , shown i n P l a t e I. Two were used f o r a c c l i g a t i o n and the other f o u r as experimental tanks to examine three d e n s i t i e s of o y s t e r s ( 16, 32 and 48 o y s t e r s per 1 2 tank r e s p e c t i v e l y ) , pl u s a c o n t r o l (no o y s t e r s ) . A l l tanks had i n s i t u c i r c u l a t i m g pumps t o keep the system homogenous. Throughout the; t e x t , A and B are i n c l u d e d i n the i d e n t i f i c a t i o n of experiments as a r e f e r e n c e to the a p p r o p r i a t e tank system. ,-Methodology The same sampling procedures were f o l l o w e d f o r a l l experiments.; Water samples ( 4 l i t r e s ) were, taken from the f i v e • s t a t i o n s * i n the p r o d u c t i o n system ( i n f l o w ( I ) , s u r f a c e (S), mid(M), bottom(B) and outflow(O) ) between 0800 and 0900 hours (PST) f o r the measurement of p h y s i c a l , chemical and b i o l o g i c a l parameters., The samples were analyzed i n the l a b o r a t o r y a c c o r d i n g t o the methods o u t l i n e d below. Measurements on the e x p e r i m e n t a l animals were made i n the aquarium wet-lab to minimize h a n d l i n g . A d e s c r i p t i o n and d e r i v a t i o n of the v a r i a b l e s and parameters which p e r t a i n e d t o the primary systems are summarized i n Appendix 1., P h y s i c a l Parameters; L i g h t , Temperature and S a l i n i t y During Experiment 1, continuous a r t i f i c i a l r a d i a t i o n was provided by V i t a l i t e f i f l u o r e s c e n t tubes, which simulated s o l a r r a d i a t i o n i n s p e c t r a l composition i n the range of p h o t o s y n t h e t i c a l l y a v a i l a b l e r a d i a t i o n (Pfifi) from c a . 400-700 nm,; There was no d i f f e r e n c e i n the r a d i a t i o n i n t e n s i t i e s of 0.10 l a n g l e y min -* between the d u p l i c a t e c u l t u r e tanks, and a 5% decrease i n PA8 a t the periphery of each t a c k was not considered 13 a s i g n i f i c a n t r e d u c t i o n . During the experiments conducted outdoors, measurement of the i n c i d e n t s o l a r r a d i a t i o n (SB) was c o n t i n u a l l y recorded under the p l e x i g l a s s sheet c o v e r i n g the experimental tanks, using a s o l a r i m e t e r (5% p r e c i s i o n ) with a c a l i b r a t e d YSIS r e c o r d i n g m i l l ! v o l t m e t e r ( c h a r t speed= 2" per hour). The p l e x i g l a s s reduced the i n c i d e n t s o l a r r a d i a t i o n by 1Q8. The l i g h t c u r v e s were i n t e g r a t e d f o r f o u r hour i n t e r v a l s , i n c l u d i n g the p e r i o d of the primary p r o d u c t i v i t y experiments, and then summed f o r d a i l y r a d i a t i o n e s t i m a t e s ( l a n g l e y d a y - 1 ) . , E s t i m a t i o n of the p h o t o s y n t h e t i c a l l y a c t i v e r a d i a t i o n (PflB) was based on S u c k l i n g (1974) who determined e x p e r i m e n t a l l y t h a t the PAB was not a f u n c t i o n of c l o u d c o v e r , and: PAB = 0.50 SB • 0.0 (r*=0.S6) S i m i l a r r e s u l t s were p r e v i o u s l y found by S z e i c z (1966). r A submarine photometer (Haddux, 1966) was placed i n the e x p e r i m e n t a l tank to determine the s o l a r r a d i a t i o n a t depth (PARZ) by measuring the e x t i n c t i o n c o e f f i c i e n t (EXTK)., However, c o n t i n u a l problems with seawater leakage i n t o the p h o t o c e l l produced u n r e l i a b l e measurements; consequently, e s t i m a t e s of EXTK were based on B i l e y ' s e m p i r i c a l . r e l a t i o n between the e x t i n c t i o n c o e f f i c i e n t and the c h l o r o p h y l l a c o n c e n t r a t i o n : EXTK = .04 • (.0088*CHJLA) • (.054* (CHLA**.66667) ) which proved r e l i a b l e f o r a range of c h l o r o p h y l l ^ v a l u e s when other p a r t i c u l a t e matter was minimal ( S i l e y , 1956)• Temperatures were measured t o 0.1 .PC using a thermometer i n s e r t e d i n t o the seawater sample., During the f i r s t h a l f of Experiment 1, i n s i t u t h e r m i s t o r s connected to a 2-channel 14 Bustrakfi , recorded temperatures at the s u r f a c e and bottom of the two p r o d u c t i v i t y tanks, p r i m a r i l y to d e t e c t any evidence of thermal i n s t a b i l i t y . Temperature f l u c t u a t i c n s of c a . • 0.2 °C occurred i n the tanks only d u r i n g the ten minute sampling p e r i o d each day.,. S a l i n i t y samples were c o l l e c t e d d a i l y i n s a l i n i t y b o t t l e s from the i n f l o w and analyzed using ia EeckmanS s a l i n o m e t e r . N u t r i e n t Parameters N i t r a t e , ammonia, urea, r e a c t i v e phosphorous and s i l i c a t e n u t r i e n t s were determined u s i n g t h e methods o u t l i n e d i n S t r i c k l a n d and Parsons (1972). D a i l y samples f o r n i t r a t e d e t e r m i n a t i o n s were analyzed using the cadaium-copper r e d u c t i o n column method, e i t h e r manually i n Experiments 1 t o 3, or . with a Technicons Auto-analyzer i n Experiments 4 and 5.. The samples were s t o r e d a t 2 °C i n the dark and u s u a l l y analyzed w i t h i n a few days of c o l l e c t i o n ; ho*ever> there was no s i g n i f i c a n t change (P<»01) i n c o n c e u t r a t i o n s of n i t r a t e with a storage d u r a t i o n of e i g h t days. The p r e c i s i o n of the method was 2%, measured over the range of i n s i t u c o n c e n t r a t i o n s ( 0 - 25 uM N 1 _ 1 ) and d i f f e r e n c e s between the manual and automated methods were not s i g n i f i c a n t s i n c e the columns were r e p l a c e d at the f i r s t s i g n of d e t e r i o r a t i o n i n e i t h e r case (Hager e t a l . , 1972)., Ammonia c o n c e n t r a t i o n s were determined manually u s i n g the p h e n o l - h y p o c h l o r i t e method. Although c a r e was taken t o reduce contamination of samples by a c i d c l e a n i n g glassware, c o v e r i n g f l a s k s and using double d e i o n i z e d d i s t i l l e d water, the p r e c i s i o n of the method ( S.E.= 0.26 uM N l - 1 ; n=3 ) was poor r e l a t i v e to 15 the low i n s i t u c o n c e n t r a t i o n s ( < 2.0 uH N 1~ 1 ) . Urea a n a l y s i s was based on the urease method with the i n h e r e n t problems of the ammonia a n a l y s i s . . Since ammonia and urea samples were f r o z e n f o r a few weeks before a n a l y s i s , v a r i a b i l i t i e s i n the c o n c e n t r a t i o n s of these n u t r i e n t s may have i n c r e a s e d < Degobbis, 1973).. Only o c c a s i o n a l measurements of phosphorous and s i l i c a t e were taken s i n c e n i t r o g e n appeared to be the primary n u t r i e n t l i m i t i n g phytoplankton p r o d u c t i v i t y , l i k e many c o a s t a l ecosystems., Primary Parameters: Standing Stocks Primary P r o d u c t i v i t y , and Community S t r u c t u r e The standing stock of phytoplankton was u s u a l l y measured every day at a l l f o u r i n s i t u s t a t i o n s as the c o n c e n t r a t i o n of c h l o r o p h y l l a (CHLA) , as o u t l i n e d i n S t r i c k l a n d and Parsons (1972).., water samples were f i l t e r e d through 0.8 micron H i l l i p o r e S AA f i l t e r s and the pigments e x t r a c t e d immediately i n 10.0 ml of spectrophotometric grade acetone. The tubes were s t o r e d i n a f r e e z e r f o r two t o seven days before c h l o r o p h y l l , c a r o t e n o i d and phaeopigments were determined using a Beckman acta 116 spectrophotometer. C a l c u l a t i o n s of pigment c o n c e n t r a t i o n s were based on the Parsons and S t r i c k l a n d (P.S.). e q u a t i o n s , although there was no d i f f e r e n c e tetween these and the SC01/UNESC0 (S/U) equations f o r CHLA: CHLA(P.S.) = 1.0 * CHLA (S/U) '<r*=1..0; tt=41) The p r e c i s i o n of the method at the 30 ug C h i a 1-* l e v e l was an average standard e r r o r of 0.5 ug C h i a l - * , based on e i g h t d u p l i c a t e d e t e r m i n a t i o n s . 16 To estimate the phytcbenthic s t a n d i n g stock, p l e x i g l a s s p l a t e s were suspended i n the primary tanks, each with f o u r 2 cm x 6 cm g l a s s s l i d e a t t a c h e d by p l a s t i c c l i p s , algae was scraped from both s i d e s of the s l i d e ( 20 cm 2 ) cntc a preweighed GFC f i l t e r , and d u p l i c a t e c h l o r o p h y l l a and biomass e s t i m a t e s were determined. ., Primary p r o d u c t i v i t y was estimated approximately every t h r e e days as net carbon f i x e d per l i t r e per hour using the method o u t l i n e d i n S t r i c k l a n d and Parsons (1972). A 100 ml water sample was p l a c e d i n a s m a l l (112 ml) ECD b o t t l e and one ampoule cf 5 uC r a d i o a c t i v e sodium bicarbonate ( i n 3% NaCl s o l u t i o n ) added to this.„ T h i s production b o t t l e and a corresponding dark b o t t l e were suspended h o r i z o n t a l l y i n the e x p e r i mental tank using p l e x i g l a s s h o l d e r s , and i n c u b a t e d f o r 4.0 hours from c a . , 0900 - 1300 hours (PST). A f t e r i n c u b a t i o n , the samples were immediately f i l t e r e d through 0.45 micron HA M l l i p o r e S f i l t e r s , then p l a c e d i n s c i n t i l l a t i o n v i a l s c o n t a i n i n g 15 ml of AguasolB s c i n t i l l a t i o n f l u i d . , Samples were counted t w i c e , each f o r ten minutes, u s i n g a Packard T r i ^ C a r b LSCS . The determination of carbonate carbon r e q u i r e d to c a l c u l a t e the r a t e of carbon f i x a t i o n *as based on the pH method. P r e c i s i o n estimates f o r **C p r c d u c t i v i t y between d u p l i c a t e b o t t l e s ranged frcm a c o e f f i c i e n t of v a r i a t i o n of 11% f o r v a l u e s < 10 ag C 1~* hr~* t o 9% f o r p r o d u c t i v i t i e s ^ 75 ug C l-» hr-* Exudation of o r g a n i c carbon was determined once a week using a m o d i f i c a t i o n of the methodology o u t l i n e d i n Anderson and Z e u t s c h e l (1970). 5 ml of f i l t r a t e from the »*C p r o d u c t i v i t y 17 samples were a c i d i f i e d with phosphoric a c i d to a pH of 3.0 and then bubbled with n i t r o g e n gas f o r 20 minutes to remove any i n o r g a n i c r a d i o a c t i v e carbon.,, 2 ml a l i q u o t s were t r a n s f e r r e d t o s c i n t i l l a t i o n v i a l s c o n t a i n i n g 10 ml of aguascie s c i n t i l l a t i o n f l u i d and the prepared samples counted foe 10 minutes. Oxygen samples were taken on a d a i l y b a s i s i n 300 ml BOD b o t t l e s , except i n Experiment 1. They were f i x e d immediately and s t o r e d i n the dark f o r a n a l y s i s w i t h i n a day or two. An a n a l y s i s of variance d u r i n g Experiment 3 i n d i c a t e d t h a t there was no s i g n i f i c a n t d i f f e r e n c e i n oxygen c o n c e n t r a t i o n between b o t t l e s s t o r e d i n t h i s manner. Primary p r o d u c t i v i t y and r e s p i r a t i o n were a l s o estimated using the l i g h t and dark b o t t l e oxygen technique ( S t r i c k l a n d and Parsons, 1972). L i g h t and dark BOD b o t t l e s were suspended h o r i z o n t a l l y by p l e x i g l a s s h o l d e r s d u r i n g the same period as the r a d i o a c t i v e carbon experiments., a p h o t o s y n t h e t i c q u o t i e n t of 1.2 and a r e s p i r a t o r y q u o t i e n t of 1.0 were used i n the c o n v e r s i o n t o carbon u n i t s . The p r e c i s i o n of the method based on d u p l i c a t e s was a c o e f f i c i e n t of v a r i a t i o n of 0.831 at the 325 mg oxygen l ~ l h r ~ l l e v e l , 1.0% a t the 300 mg oxygen l " 1 hr-* and 7.5% a t t h e 250 mg oxygen I - * h r - * l e v e l . . Water samples (250 ml) were a l s o c o l l e c t e d semi-weekly f o r phytoplankton s p e c i e s composition aDd s i z e d e t e r m i n a t i o n . , a 10 ml; subsample was f i x e d with l u g o l s o l u t i o n and examined i n a 5 c c s edimentation chamber with a Z e i s s i n v e r t e d microscope. , The remaining sample was s t o r e d at 2 °C i n the dark u n t i l i t c o u l d be counted on a Model B c o u l t e r Counters as o u t l i n e d i n Sheldon and Parsons (1S67)., The a n a l y s i s employed a flow-through r a t e 18 of 0.044 ml s e c — i using a 100 micron aperature. Eleven p a r t i c l e diameters ranging from 2.82 to 28.5 microns were counted i n t r i p l i c a t e and then averaged. Secondary P r o d u c t i v i t y  Experiment 1 S c a l l o p s { Chlamys h a s t a t a b e r i c i a ) were c o l l e c t e d a t ca. 20 metres by d i v e r s near V i c t o r i a , B r i t i s h Columbia two weeks b e f o r e the s t a r t o f Experiment 1 (EXP1). .They were put i n t o h o l d i n g . t a n k s and provided with a constant supply of seawater from the r e s e v o i r tank (Figure 1). Ten l i t r e s o f s u r f a c e seawater from E n g l i s h Bay were added to the tanks every couple o f days. 50 h e a l t h y s c a l l o p s were s e l e c t e d as experimental animals, * and a few were cleaned of e n c r u s t i n g sponges ( M y x i l l a  i n c r u s t a n s , fiycale adhaerens ) . The s c a l l o p s were tagged, weighed and measured, and added t o the benthos of Tank A on Day 45. A f t e r one month, the Chlamys were re-measured and weighed t o d e terBine t h e i r growth., Experiment 2A C r a s s o s t r e a g i g a s c u l t c h were obtained from a commercial grower near V i c t o r i a on A p r i l 25 and kept i n a 3000 l i t r e h o l d i n g tank with u a f i l t e r e d running seawater ( ca. 29 ppt, 13 1 The l a r g e r s c a l l o p s with the b o r i n g sponge C l i o n a c e l a t a were r e j e c t e d . 1 9 °C ) . 10 l i t r e s of phytoplankton s t o c k were added t o the h o l d i n g tank every couple of days. Twelve c u l t c h were tagged f o r i d e n t i f i c a t i o n and t r a n s f e r r e d at the beginning of EXP2ft t o s m a l l e r tanks r e c e i v i n g the outfl o w from Tank A. The t o t a l weight, weight i n water and number of o y s t e r s per c u l t c h were measured b e f o r e t h e i r a d d i t i o n to t h e one-stage c o n t i n u o u s c u l t u r e experiment on Day 6. Four s t r i n g s , with c u l t c h a t the s u r f a c e (0.1m), mid (0.5 m) and bottom i(0-9m) depths, were l o c a t e d a t s u b s t a t i o n s 1 to 4 (Figure 2 ) . . The o y s t e r s were grown f o r f i v e weeks before the f i n a l measurements were made of the growth v a r i a b l e s . Experiment 2B At the beginning of EXP2B, s i x dozen s c a l l o p s were c o l l e c t e d at the same l o c a t i o n i n V i c t o r i a and 64 were s e l e c t e d as e x p e r i m e n t a l animals. They were ordered ±y l e n g t h and weight i n t o f o u r groups of i n c r e a s i n g s i z e , and w i t h i n each group of 16 s c a l l o p s , one-half were randomly s e l e c t e d f o r a cage t o be l o c a t e d a t mid depth and the oth e r h a l f f o r a cage t o be l o c a t e d at the bottom s t a t i o n . The same procedure was adopted f o r the three l a r g e r s i z e groups. The s c a l l o p s were acc l i m a t e d f o r f o u r days i n s m a l l covered tanks f e d by the outflow from Tank B. A f t e r the s c a l l o p s were weighed and measured, the cages were t r a n s f e r r e d on Day 10 of EXP2B to t h e i r designated s u b s t a t i o n . The f o u r cages a t the mid depth were l o c a t e d at s u b s t a t i o n * s 1 t o 4, while the f o u r cages a t the bottom depth were l o c a t e d a t s u b s t a t i o n * s 5,8,9 and 12 (Figure 2 ) • r One month l a t e r , f i n a l measurements were made of the growth v a r i a b l e s . , 20 Experiment 3A The 24 o y s t e r c u l t c h s e l e c t e d f o r EXP3A were tagged and t r a n s f e r r e d during EXP2A to the s n a i l h o l d i n g tanks f e d by the outflow from Tank A. The growth v a r i a b l e s were measured on Day 6 of EXP3A, and 8 s t r i n g s with c u l t c h a t the s u r f a c e , mid and bottom depths, were l o c a t e d at s u b s t a t i o n s 1 to 8 i n Tank A. P i n a l measurements were taken a f t e r two weeks of growth. Experiment 3B Another nine dozen s c a l l o p s were c o l l e c t e d a t the same V i c t o r i a l o c a t i o n on Day 7 of EXP3B. The same procedure used i n EXP2B was adopted f o r the s e l e c t i o n of the 96 experimental animals and grouping them i n t o f o u r c l a s s e s of i n c r e a s i n g s i z e . I n t h i s experiment (EXP3B), there "ere enough s c a l l o p s to s t r i n g f o u r cages ( c o n t a i n i n g 8 s c a l l o p s per cage) at the s u r f a c e depth (SUBSTWs 6,7,10 and 11) as w e l l as the mid and bottom s t a t i o n s . The s c a l l o p s were a c c l i m a t e d f o r three dajs as i n EXP2B, and a f t e r they were weighed and measured, the cages were t r a n s f e r r e d on Day 11 to the a p p r o p r i a t e SUBSTN i n Tank - B. The f i n a l measurements sere made of the growth v a r i a b l e s a f t e r one month. Experiment 5 J u v e n i l e C r a s s o s t r e a giqas were o b t a i n e d from a commercial o y s t e r grower near V i c t o r i a , B r i t i s h Columbia and h e l d i n a 3000 l i t r e tank outdoors u n t i l t h e s t a r t c f v the h e r v i v o r e experiments. U n f i l t e r e d running seawater (29 ppt, 13 °C) was c o n s t a n t l y s u p p l i e d t o the h o l d i n g tank and 10 l i t r e s of 21 phytoplankton stock were added to the tank every Couple of days. A sm a l l h o l e ( 1 / 3 2 * * ) was d r i l l e d i n the unto of the s h e l l f o r w i r i n g t h e o y s t e r s t o small square p l e x i g l a s s boxes designed to s i m u l a t e c u l t c h ( P l a t e I I ) , so growth v a r i a b i l i t y between and w i t h i n s i z e groups c o u l d be a s s e s s e d . D e t a i l s of the design of the two-stage continuous c u l t u r e experiments are presented i n Chapter 7. 1 be l i n e a r dimensions ( l e n g t h , width and depth) , weight i n a i r ( i 0.1 g), weight i n water, and whole volume of the i n d i v i d u a l o y s t e r s were measured as growth v a r i a b l e s . A d e s c r i p t i o n and the d e r i v a t i o n of the v a r i a b l e s p e r t i n e n t t o the h e r b i v o r e growth experiments are summarized i n Appendix 2 . . • 22 CHAPTEB 3. ONE—STAGE GQNTINOQOS CULTOBES IK NON-TUBBOLENT OPWELLING SYSTEMS BITH CONSTANT FOBCING CONDITIONS The i n i t i a l experiment was designed and conducted to examine p h y s i c a l and b i o l o g i c a l v a r i a b l e s i n d u p l i c a t e non-t u r b u l e n t upwelling systems with a f l u s h i n g r a t e of 0.5 d a y - 1 . The experimental system, d e s c r i b e d i n Chapter 2, permitted the examination of the phytoplankton dynamics under c o n t r o l l e d , c o n s t a n t , f o r c i n g c o n d i t i o n s . T h i s experiment (EXP1) was conducted f o r ten weeks, beginning on October 1 . , A f t e r the tanks were f i l l e d with f i l t e r e d i n f l o w i n g seawater and i n i t i a l samples taken, each tank was seeded with 10 l i t r e s o f phytoplankton stock which had been c o l l e c t e d frcm the s u r f a c e of E n g l i s h Bay and passed through a small diameter (54u) wire screen to remove any zooplankton. The t e n t h i c h e r b i v o r e s , Chlamys h a s t a t a h e r i c i a , were i n t r o d u c e d i n t o Tank A on Day 45 t o determine the s u i t a b i l i t y o f t h i s continuous c u l t u r e system f o r the s u r v i v a l and growth of a l o c a l s c a l l o p p o p u l a t i o n . Dynamics of the Primary Communities The f l u s h i n g r a t e remained r e l a t i v e l y constant a t 0.5 d a y 1 throughout the experiment, although on a few days the r a t e decreased to as low as 0i45 day -* . However cn Day 31 the water l e v e l i n Tank A i n c r e a s e d by 2 i n c h e s due to c l o g g i n g of the i n s i t u l e v e l l i n g p i p e by a f i l a m e n t o u s N a v i c u l a mat which had been growing on the overflow pipe s i n c e Day 13. ( The same problem occurred i n Tank B or Day 43 although the s i t u a t i o n was 23 more severe s i n c e the tank overflowed f o r about h a l f an hour. In each case, the N a v i c u l a around the pipe were removed. P h y s i c a l Environment The continuous source of p h o t o s y n t h e t i c a l l y a v a i l a b l e r a d i a t i o n o f 0.10 l a n g l e y a i n - * r epresented a d a i l y r a d i a t i o n f l u x of 144 l a n g l e y d a y - 1 . The r e s u l t i n g i n s i t u temperatures were s i g n i f i c a n t l y d i f f e r e n t between depths but e s s e n t i a l l y c o n s t a n t between tanks and w i t h i n depths f o r the f i r s t e i g h t weeks o f the experiment, averaging 14.5 °C (± -1 °C ) a t the s u r f a c e , 12.0 °C (± . 1 °C ) at t h e mid s t a t i o n and 10.5 °C (± . 1 °C ) at the bottom s t a t i o n . During the l a s t two weeks, the average temperature decreased c a . 3 °C a t the s u r f a c e o f the tanks and c a . ,; 1,5 °C at the mid and bottom s t a t i o n s . The temperature and s a l i n i t y of the i n f l o w i n g seawater was constant a t 10.0 °C <± .1 oc ) and 2.9.2 ppt (± 0.6 ppt) dur i n g EXP1. N u t r i e n t C o n d i t i o n s The c o n c e n t r a t i o n s of the n u t r i e n t s important i n phytoplankton p r o d u c t i v i t y sere measured a t v a r i o u s times d u r i n g the experiment. Samples of the i n f l o w i n g seawater were analyzed b e f o r e the s t a r t of EXP 1, with the r e s u l t i n g average c o n c e n t r a t i o n s : n i t r a t e (N03) = 17.8 uH H.Ir* , ammonia (NH3) = 0.88 UH N l - i , phosphate <P04) = 1.75 ufi P 1~* , s i l i c a t e (SI03) = 71.3 ufl S i 1~* . The r a t i o s of these n u t r i e n t c o n c e n t r a t i o n s suggested t h a t the e x p e r i m e n t a l system would 24 probably be n i t r o g e n - H a l t e d * . The c o n c e n t r a t i o n of n i t r a t e during EXP 1 i s i l l u s t r a t e d i n F i g u r e s 6 and 7 . T h e high i n f l o w BC3 was r e l a t i v e l y c o n s t a n t , averaging 23.6 uH N 3>» (SE = 0.39 u « J 1~* ;n=35) du r i n g the f i r s t f i v e weeks. The p a t t e r n of damped o s c i l l a t i o n s f o r the i n s i t u n i t r a t e c o n c e n t r a t i o n was s i m i l a r between tanks f o r the f i r s t t h r e e weeks, with an NG3 minimum of <2 U H N I T * -by Day 10, recovery to l e v e l s of .ca. 15 uM N 1~ 1 by Day 15, and then a decrease t o c i t r a t e c o n c e n t r a t i o n s of 2-5 uM N l~l ., Throughout the experiment, the N03 a t the botton s t a t i o n was s i g n i f i c a n t l y g r e a t e r than the s u r f a c e c o n c e n t r a t i o n . During the f o u r t h and f i f t h weeks, the average n i t r a t e . l e v e l s i n Tank B were about twice as h i g h as i n Tank A., There was a high negative c o r r e l a t i o n between N03 a t the s u r f a c e and bottom s t a t i o n s f o r the: d u r a t i o n of EXP1 A.„ The same trend was cot apparent i n Tank B, although t h i s may have been p a r t l y due to the tank o v e r f l o w i n g on Day 4 3. The average weekly i n f l o w c o n c e n t r a t i o n of phosphate was 2.43 uH P I - * to b o t h t a n k s . As i n the case cf N03, the P04 a t the bottom s t a t i o n was g r e a t e r than the phosphate c o n c e n t r a t i o n a t the s u r f a c e and outflow s t a t i o n s . Phosphate l e v e l s were never , l e s s than 0.5 uH P I - 1 , even when N03 values were ca. 2 uB : N 1-* , i n d i c a t i n g t h a t P04 d i d not l i m i t primary p r o d u c t i v i t y . A f t e r the i n t r o d u c t i o n of the s c a l l o p s to the system, the d i f f e r e n c e between the net c o n c e n t r a t i o n of ammonia at the 1 R e s u l t s from A n t i a e t a l . (1963) i n d i c a t e d that a s i m i l a r primary community had a N/P r a t i o g r e a t e r than 12, whereas the N/P r a t i o of the seawater source was only .10. 25 bottom s t a t i o n was s i g n i f i c a n t l y higher i n Tank ft (1.50 uM N I - 1 ) than Tank E (0,10 uM N 1~» ) . y Phytoplankton Dynamics Standing Stock The phytoplankton stock was measured as the c h l o r o p h y l l a c o n c e n t r a t i o n (CHLA) every two t o three days f o r the f i r s t f i v e weeks o f EXP 1.. During t h i s time, the phytoplankton s t o c k g e n e r a l l y f o l l owed a p a t t e r n of damped o s c i l l a t i o n s i n both tanks, with the i n i t i a l bloom on Days 8 and 9, a reduced secondary maximum approximately two seeks l a t e r and a t h i r d i n c r e a s e a t the end of the f i v e week p e r i o d (Figures 8 and 9 ) . The s t o c k l e v e l s i n c r e a s e d s i g n i f i c a n t l y with depth throughout EXP1. The magnitude of the blocm was the same i n both tanks, averaging 52*9 ug C h i a 1-* and 54.5 ug C h i a l ~ i i n Tanks A and B r e s p e c t i v e l y , although the secondary phytcplankton maximum was not as l a r g e i n Tank B. T h i s probably r e s u l t e d from the f a c t t h a t t h e benthic diatom, N a v j c u l a sp., , which was more p r e v a l e n t i n Tank B, f u r t h e r reduced the PAB at depth i n a system which was already l i g h t - l i m i t e d . A comparison of CHLft between tanks A and B during the post-blccm p e r i o d (t>t0), produced averages of 18.8 ug C h i a h 1 (SD=5.19) and 7.4 ug C h i a l - i (SD=6.49) at the s u r f a c e , 21.2 ug C h i a 1-* (SD=9.17) and 16.1 ug Chi a - l - i (SD=9.88) at the nid depth, and 29.1 ug Chi a l - i (SD= 18.57) and 27.Q ug C h i a l - i <SD=16.?4) at the bottom depth.. 26 A f t e r the s c a l l o p s were added t o Tank A on Day 45, the phytoplankton stock was reduced t o l e s s than 5 ug C h i a l - 1 at the bottom s t a t i o n , which was l e s s than the s u r f a c e and mid s t a t i o n s and ca. 40 ug C h i a 1~» l e s s than the cor r e s p o n d i n g value f o r Tank B. During the i n i t i a l bloom, e s t i m a t e s were made i n both tanks o f the phytoplankton stock which sank t o the benthos 1 . The phytobenthos was measured cn Days 9, 10 and 14 as 180 ug C h i a 1~» (± 5 ug C h i a 1-* ) , 256 ug Chi a 1-* (± 11 ug , C h i a l-» ) and 343 ug C h i a l - i (± 11 ug C h i a 1~* ) , which r e p r e s e n t e d an average value of 23.4 ug C h i a I - 1 d a y - 1 .... On average, the phytobenthos c o n c e n t r a t i o n was approximately 2.5 times the phytoplankton c o n c e n t r a t i o n i n the water column, r e p r e s e n t i n g an average net s i n k i n g r a t e of 1.0 m/day or 1.4 m/day with r e s p e c t t o the water column. ? Primary P r o d u c t i v i t y Primary p r o d u c t i v i t y r a t e s cn hourl y b a s i s were low i n both tanks d u r i n g the experiments ( F i g u r e s 10 and 11). Values were l e s s than 30 ug C 1~* h r - * , except on Day 49 a t the bottom station... When s t a n d a r d i z e d on a st a n d i n g stock b a s i s , primary p r o d u c t i v i t i e s (ASS) ranged from 0.0 ug C (ug Chla)-» hr-* a t the bottom s t a t i o n t o a value of 5.1 ug C (ug C h l a ) - 1 h r - 1 on Day 19 as i l l u s t r a t e d i n F i g u r e 12., The values of ASS were s i m i l a r between tanks but decreased s i g n i f i c a n t l y with depth. * C i r c u l a r p l e x i g l a s s c o l l e c t o r s were c o n s t r u c t e d and placed at known l o c a t i o n s on the bottom of the tank before the s t a r t of E X P L y These c o l l e c t o r s were r e t r i e v e d by p l a c i n g a c o v e r i n g p l a t e (with an 0 - r i n g on the i n s i d e surface) a t t a c h e d to an i n f l e x i b l e 1 metre r o d , over the benthos c o l l e c t o r and b r i n g i n g i t to t h e s u r f a c e . 27 E x c l u d i n g Day 19, the s t a n d a r d i z e d p r o d u c t i v i t y r a t e s d u r i n g t h experiment averaged 0.96 ug C (ug Chla)-» h r ~ l (av SD=.40), 0.76 ug C (ug Chla)-» h r ~ 4 (av SD=.21) and 0.40 ug C (ug C h l a ) - * h r - i (av SD=.26) at t h e s u r f a c e ^ mid and bottom s t a t i o n s r e s p e c t i v e l y . , Phytoplankton Stock Composition During the i n i t i a l bloom, Skeletonema costatum was the dominant ; p h y t o p l a n k t e r , although : s e v e r a l other s p e c i e s of diatoms ( N J t z s c h i a spp. , , T h a l a s s i o s i r a scp., , N a y i c u l a sp. # Chaetoceros sp. ) were a l s o present. Increased numbers and d i v e r s i t y of n a n o - f l a g e l l a t e s * were apparent a t the s u r f a c e s t a t i o n d u r i n g the t h i r d and f o u r t h weeks. , By the end of the s i x t h week. Skeletonema costatum was not present i n the s u r f a c e samples. Three d i n o f l a g e l l a t e s ( p e r i d i n i u m sp. , Gymnodinium s£. , Dinophysis SP. ) , a green f l a g e l l a t e , and the f i l a m e n t o u s H a v i c u i a s g . were the dominant phy t o p l a n k t e r s . The dominance of Skeletonema costatum at the mid and bottom s t a t i o n s was r e p l a c e d by H i t z s c h i a spp. , T h a l a s s i o s i r a sp. , and B h i z o s o l e n i a sp. A f t e r t h e s c a l l o p s were added t o Tank A. Chaetoceros sp. became the dominant Phytoplankter at the bottom s t a t i o n compared with T h a l a s s i o s i r a SP. i n Tank B. 1 F l a g e l l a t e s i n the 2-20 micron s i z e range (See Parsons and Takahashi (1973a), p.6). 28 Growth and S u r v i v a l of the S c a l l o p P o p u l a t i o n The r e s u l t s o f Experiment 1 i n d i c a t e d t h a t the non-t u r b u l e n t upwelling system with a moderate exchange r a t e (0.5 day-* ) provided a s u i t a b l e environment for the growth of Chlamys h a s t a t a h e r i c i a . a f t e r the s c a l l o p s were i n t r o d u c e d t o the benthos of Tank a on Day 45, the amount of d e t r i t u s and phytoplankton at the bottom s t a t i o n was reduced and the s c a l l o p s were o f t e n observed swimaing i n the v e n t r a l d i r e c t i o n * i n d i c a t i n g t h e i r need f o r removal of pseudofeces. ;« The 50 s c a l l o p s ^ ranged i n l e n g t h from 3.0 cm to 6,6 cm and weighed 5.Og t o 51.7g i n i t i a l l y . . The frequency d i s t r i b u t i o n o f the e x p e r i m e n t a l p o p u l a t i o n based on l e n g t h (L) i n d i c a t e d t h a t 30 of the 50 Chlamys were i n the 4.0-4. 9 cm range, a v e r a g i n g 4.5 cm (SD*. 25). , The 8 s c a l l o p s i n the 3.0-3.9 cm range averaged 3.5 CB (SD=.29) i n l e n g t h . Cf the remaining 12 s c a l l o p s , 7 were i n the 5.0-5.9 cm range (av 1= 5.4cm; SD=.22) and 5 were l o n g e r than 6.0 cm (av 1= 6.2cm; SD=.33). The corresponding t o t a l weight per s c a l l o p at t (0) averaged 6.2g (SD=. 33) , 12.6g (SD=2.77) , 24.5g (SD=3.35) and 37.Og (SD=1C28) f o r the f o u r s i z e groups. a f t e r the f o u r week growth experiment, most of the Chlamys had l a i d down a t h i n , d a r k l y pigmented band of new s h e l l . The average i n c r e a s e i n l e n g t h (NETL) and width (NETH) of the s c a l l o p p o p u l a t i o n was 0.09 ca (SD=. 096) and 0.05 cm (SD=.085), which represented growth r a t e s of 2,0% and 1..2E r e s p e c t i v e l y d u r i n g t h e month. However, NETL was a l s o a f u n c t i o n of the s i z e o f t h e s c a l l o p s , and the net l e n g t h as a percent i n c r e a s e from 29 the i n i t i a l l e n g t h (PEEL) , ranged from 5.1.1 f o r the s m a l l s i z e group to 2.0$, 1.8% and 0.0% f o r the three l a r g e r s i z e c l a s s e s r e s p e c t i v e l y . The average i n c r e a s e i n t o t a l weight (NETWT) was 2.1%, although .NETHT was a l s o a f u n c t i o n of the s i z e o f the s c a l l o p s . The s m a l l e s t c h l a a y s had the h i g h e s t growth r a t e s o f 6.9%, compared with r a t e s o f 2. 9S, 1.3% .and 2.7% f o r t h e . l a r g e r s i z e c l a s s e s . The 60* depth of the seawater i n t a k e at the I n s t i t u t e was s i m i l a r to the depth from which the s c a l l o p p o p u l a t i o n was c o l l e c t e d , s u g g e s t i n g t h a t t h e i r endemic p h y s i c a l environment of temperature and s a l i n i t y was probably f a i r l y s i m i l a r t o the experimental conditions.,. Although the l i g h t i n t e n s i t y was h i g h e r than the n a t u r a l environment, the Chlamys d i d not seem bothered by t h i s , and were observed a c t i v e l y f e e d i n g on the phytobenthos and o c c a s i o n a l l y swimming around the tank. The most s i g n i f i c a n t d i f f e r e n c e between the n a t u r a l and ex p e r i m e n t a l environments was the phytobenthic c o n c e n t r a t i o n , and the r e s u l t s of t h i s experiment i n d i c a t e d t h a t t h i s type of upwelling system enhanced secondary p r o d u c t i v i t y i n the s c a l l o p food c h a i n . , 30 CHAPTER 4.„ ONE-STAGE CON1INOOOS CULTURES I J NON-TURBOLENT UPWELLING SYSTEMS «ITH NATURAL FORCING CCNDTIONS Turb u l e n t u p a e l l i n g systems a t v a r i o u s f l u s h i n g r a t e s were examined as growth environments f o r the sessile p l a n k t o n i c h e r b i v o r e s . To e v a l u a t e the c u l t u r e system under more n a t u r a l f o r c i n g c ondtions of s o l a r r a d i a t i o n and temperature, two s e t s o f c o n t r o l l e d experiments (designated as Experiments 2 and 3) were conducted outdoors i n d u p l i c a t e tank- systems a t low and high f l u s h i n g r a t e s . In Experiment 2, the dynamics o f the primary communities and the growth of two d i f f e r e n t h e r b i v o r e p o p u l a t i o n s were examined i n one-stage continuous c u l t u r e s at f l u s h i n g r a t e s of 0 . 2 5 d a y — 1 . In e a r l i e r experiments, t h i s f l u s h i n g r a t e had promoted a mixed diatom/phytof l a g e l l a t e .community and r e s u l t e d i n environmental c o n d i t i o n s p o t e n t i a l l y s u i t a b l e f o r the growth o f o y s t e r s . In EXP2, s u r v i v a l and growth of o y s t e r s ( C r a s s o s t r e a qjgas ) and s c a l l o p s ( Chlamys fcastata h e r i c i a ) were, examined i n Tank A and Tank B r e s p e c t i v e l y , t o o b t a i n a f i r s t approximation of the f a c t o r s l i m i t i n g secondary p r o d u c t i v i t y and t o compare changes i n the primary community caused by d i f f e r e n t h e r b i v o r e p o p u l a t i o n s . Based i n part on the r e s u l t s of EXP2, a s i m i l a r one-stage continuous c u l t u r e system was re-examined i n Experiment 3 with the f o l l o w i n g m o d i f i c a t i o n s : 1. Tank A was stocked with twice the d e n s i t y of h e r b i v o r e s ( o y s t e r c u l t c h a t e i g h t s u b s t a t i o n s ) while using the same f l u s h i n g r a t e (0.25 d a y - 1 ) s i n c e optimal temperatures and 31 s u i t a b l e phytoplankton s t o c k s were produced i n t h i s system, 2, Tank B was s t o c k e d with s c a l l o p s at the s u r f a c e , mid and bottom depths but the f l u s h i n g r a t e was i n c r e a s e d t h r e e - f o l d to 0,75 day-* t o promote a s u i t a b l e growth environment f o r these h e r b i v o r e s p r i m a r i l y by lowering the i n s i t u temperature. Comparison of Two Herbivorous Food Chains at- a Low F l u s h i n g Rate Both production tanks A and B were f i l l e d with f i l t e r e d seawater on June 18, the f l u s h i n g r a t e s a d j u s t e d to 0,25 d a y - 1 and t h e . i n i t i a l p h y s i c a l and c h e m i c a l c o n d i t i o n s monitored at 090,0 hr (PST). S u r f a c e seawater from E n g l i s h Bay was c o l l e c t e d and f i l t e r e d through a 54u n e t t i n g t o remove zooplankton,, 20 l i t r e s of t h i s n a t u r a l phytoplankton community were added to the s u r f a c e of each p r o d u c t i o n tank a t 1100 h r . , T h i s seed community c o n s i s t e d mainly of diatom c h a i n s , predominantly Skeletonema  costatum and T h a l a s s i o s i r a sp. , as w e l l as N i t z s c h i a spp. , N a v i c u l a sp. , and a few n a n o - f l a g e l l a t e s . , The f l u s h i n g r a t e s remained r e l a t i v e l y c onstant a t 0.25 day-* i n both tanks d u r i n g the experiment. I n the o y s t e r tank, the 5% c o e f f i c i e n t of * v a r i a t i o n (CV) f o r the f l u s h i n g r a t e was p r i m a r i l y due to growth of the f i l a m e n t o u s i»enthic diatom, N a v i c u l a •§•£.., , around the i n f l o w p i p e , reducing the flow r a t e i n t o the tank. T h i s was not apparent u n t i l Day 33 a t which time the a l g a l mat was removed,„ The t o t a l d u r a t i o n o f Experiment 2 was 6 weeks i n Tank A {EXP2A) and 5 weeks i n Tank B (EXP2B)., The C r a s s o s t r e a gigas p o p u l a t i o n 32 was added t o Tank & on Day 6. The cages c o n t a i n i n g the Chlaiays were s t r u n g a t the a p p r o p r i a t e s u b s t a t i o n s on Day 10, as o u t l i n e d i n Chapter 2. , Dynamics o f the Primary Communities The dynamics o f the p h y s i c a l , c h e m i c a l and primary p r o d u c t i v i t y v a r i a b l e s f o r both Tank ft and Tank B are i l l u s t r a t e d i n F i g u r e s 13 to 25...;. D e s c r i p t i v e s t a t i s t i c s f o r both the f o r c i n g {incoming} and i n s i t u values of the primary v a r i a b l e s are summarized i n T a b l e s 2 and 3 f o r EXP2A and EXP28 r e s p e c t i v e l y . Shere a p p r o p r i a t e , a breakdown i n t o the pre-g r a z i n g and g r a z i n g p e r i o d s are i n c l u d e d f o r the measurements. , P h y s i c a l Environment S o l a r r a d i a t i o n a t the s u r f a c e ox the tanks (SB) ranged c o n s i d e r a b l y d u r i n g the experiments, from 110 l a n g l e y day-* on Days 6 and 7 to 550 l a n g l e y day-* f o r an extended p e r i o d during the f o u r t h week {Figure 13) 1 . The l a r g e CV of 35% based on an average SB o f 410 l a n g l e y day-* i n d i c a t e d the l a c k of an i d e a l l y c o n s t a n t s o l a r r a d i a t i o n l e v e l . , There was no s i g n i f i c a n t d i f f e r e n c e between the i n f l o w temperature of 10.9 °C to the two tanks and d u r i n g the experimental p e r i o d , i n s i t u temperatures (TEMP) f l u c t u a t e d i n response t c the v a r i a b i l i t y i n SB (Figures 14 and 15). The thermal s t r u c t u r e between the tanks was s i m i l a r , i n c l u d i n g a s i g n i f i c a n t decrease i n TEMP with depth 1 The values i n the p l o t a r e f o r i n c i d e n t SB, which was 10% h i g h e r than SB j u s t above the s u r f a c e of the water, as mentioned i n Chapter 2. T h i s was a l s o t r u e f o r t h e ether graphs of SB d u r i n g Experiments 2 and 3. 33 (Tables 2 and 3)• The d i f f e r e n c e i n temperature between the s u r f a c e and bottom depths was c a . 5 °C during the extended p e r i o d of high SH., ht sampling time during the experiments, maximum i n s i t u temperatures were ca. , 21.0 °.C , although an examination o f the d i e l temperature v a r i a t i o n on two sunny days showed t h a t '15.0 °C temperatures at sampling time i n c r e a s e d by ca. 5 °C .-at the s u r f a c e and outflow s t a t i o n s , and 2-3 °G a t the mid and bottom s t a t i o n s by l a t e a f t e r n o o n . The s a l i n i t y averaged 28.3 ppt and was e s s e n t i a l l y constant d u r i n g the experiments (C?=2.2%). N u t r i e n t C o n d i t i o n s I n i t i a l phosphate c o n c e n t r a t i o n s averaged 2*; 15 uM P I - 1 and the r e l a t i v e l y c o n s t a n t N ;P atomic r a t i o o f 8.5 f o r the i n f l o w i n g seawater i n d i c a t e d t h a t n i t r o g e n was the l i m i t i n g n u t r i e n t f o r the primary f o r m a t i o n of p a r t i c u l a t e o r g a n i c matter., , The g r e a t e s t source of n i t r o g e n was i n the form o f n i t r a t e , with i n f l o w c o n c e n t r a t i o n s averaging 18.5 uH N 1-* w i t h i n an 11-27 ua N 1-* range (CV=19S). There was no s i g n i f i c a n t d i f f e r e n c e i n i n f l o w N.Q3 between tanks except d u r i n g the f i r s t week when n i t r a t e l e v e l s i n c r e a s e d i n the i n f l o w to Tank B f o r some re a s o n . However, the f l u c t u a t i o n s i n the i n f l o w NO3 with time were r e a l and the general d e c r e a s i n g trend could be a t t r i b u t e d t o ;a d e c r e a s i n g t i d a l h e ight a t sampling.time * during the f i r s t * The i n t a k e pipe f o r the I n s t i t u t e d seawater system i s higher i n the water column a t low t i d a l h e i g h t s and s i n c e N03 i n c r e a s e d with depth, the i n f l o w contained lower n i t r a t e c o n c e n t r a t i o n s . 34 p a r t of the experiment and a l s o to an i n f l u x cf a s u r f a c e water mass (high temperatures and oxygen l e v e l s with low n i t r a t e c o n c e n t r a t i o n s ) , probably due t o unstable c o n d i t i o n s i n E n g l i s h Bay d u r i n g the l a s t week of the experiment. The high i n i t i a l i n s i t u n i t r a t e c o n c e n t r a t i o n s (22.5 uM N i ~ 1 ) were de p l e t e d at a l l s t a t i o n s , by Day 6, averaging l e s s than 1 UM N l - i d u r i n g both experiments (F i g u r e s 16 and 17).., There was a minor recovery t o n o n - l i m i t i n g n i t r a t e c o n c e n t r a t i o n s a t the end of the second and f o u r t h weeks., Inflow ammonia c o n c e n t r a t i o n s were low (max=1.85 uM N 1 - * ) , i and with an average c o n c e n t r a t i o n o f 0.74 uM N 1~* (SD=0.42) c o n t r i b u t e d l i t t l e t o the source of n i t r o g e n f o r the system. I n both p r o d u c t i o n t a n k s , NH3 remained at low steady s t a t e l e v e l s ( •ca.a,- 0.4 - 0.7 uM N lrr* ) i n d i c a t i n g t h a t any excreted NH3 by the o y s t e r s or s c a l l o p s was taken up immediately by the p h y t o p l a n k t e r s . Phytoplankton Dynamics The dynamics of the r e s u l t a n t primary communities, i n c l u d i n g the phytoplankton s t a n d i n g s t o c k (CHLA), primary p r o d u c t i v i t y (PBOD) and the primary p r o d u c t i v i t y r a t e s t a n d a r d i z e d per u n i t of s t a n d i n g s t o c k (ASS), are i l l u s t r a t e d i n F i g u r e s 18 to 25., 35 Standing Stock In the o y s t e r tank (A), a sub s u r f a c e maximum of phytoplankton ( c a . 46 ug C h i j 1-* ) developed by Day 5, fo l l o w e d by a s u r f a c e maximum of onl y h a l f t h i s c o n c e n t r a t i o n on Day 6 ( F i g u r e 18) . T h i s i n d i c a t e d t h a t s i n k i n g of the phytoplankton through the water column was a s i g n i f i c a n t f a c t o r i n determining the s p a t i a l d i s t r i b u t i o n o f the primary community and a t times was g r e a t e r than the upwelling r a t e of 0.25! m/day. During the g r a z i n g p e r i o d (t>6), CHLA decreased to average v a l u e s o f 3.3 ug C h i a 1-* a t the s u r f a c e , 4.2 ug C h i a I r * a t the mid depth* and 6.8 ug C h i a 1-* a t the bottom s t a t i o n . Except a t the bottom s t a t i o n , the p h y t o f l a n k t c n stock assumed a qua s i s t e a d y - s t a t e with biweekly p e r i o d i c o s c i l l a t i o n s of ca. 1-5 ug C h i a 1-* . A secondary c h l o r o p h y l l maximum occurred a t the bottom s t a t i o n at the end of f o u r weeks i n response t o the s i g n i f i c a n t i n c r e a s e i n the i n f l o w H03 c o n c e n t r a t i o n . In the s c a l l o p tank (8), the i n i t i a l bloom occurred at the same time (Day 6) and was s i m i l a r i n magnitude t o the o y s t e r tank. However,; the post-bloom dynamics v a r i e d t o some exte n t (Figure 19). The d u r a t i o n of the bloom was two days l o n g e r i n Tank B i n the absence of any g r a z i n g p r e s s u r e . , The standing stock during the g r a z i n g p e r i o d i n Tank B (t>10) averaged 5.7 ug C h i a 1-* , 1.6 ug Chi a 1~* more than the value d u r i n g the corresponding p e r i o d i n EIP2A. T h i s was p r i m a r i l y due to the s i g n i f i c a n t i n c r e a s e i n CHLA t o l e v e l s of ca. 13 ug C h i a l _ l subsequent t o the pe r i o d of high i n f l o w N03 a t the end of the f o u r t h week, and, as mentioned l a t e r , t o the removal of f l o a t i n g a l g a l clumps at the s u r f a c e of the tank. 3 6 Oxygen L e v e l s The oxygen c o n c e n t r a t i o n (OXX) i n the i n f l o w t o both p r o d u c t i o n systems was r e l a t i v e l y c onstant (CV=65$) d u r i n g the experiment, averaging 7 . 5 mg 1~ 1 with an average s a t u r a t i o n l e v e l of 8 2 % . , S f i t h i n the o y s t e r tank, a p o s i t i v e net production of oxygen (OXYB) was maintained and F i g u r e 2Q i l l u s t r a t e s the e f f e c t i v e damping of the oxygen l e v e l s a f t e r the i n i t i a l bloom of c a . 17 mg 1—* -. S i g n i f i c a n t d i f f e r e n c e s i n OXY occurred between depths, c o i n c i d e n t with the periods of thermal s t a b i l i t y , although f o r the t o t a l e xperimental p e r i o d , the mean c o n c e n t r a t i o n s and v a r i a n c e s were s i m i l a r between depths (Table 2 ) , averaging ca. , 11.6 mg 1~* with a Cv=24J5. The tank was s u p e r s a t u r a t e d d u r i n g most of the experiment, reachi n g a maximum of ca.„ 21 OX d u r i n g the i n i t i a l phytoplankton bloom and averaging approximately 14058 at a l l depths. The oxygen c u r v e s e x h i b i t e d a s i m i l a r p a t t e r n i n the s c a l l o p tank, but average OXY c o n c e n t r a t i o n s a t depth were lower, and l a r g e r v a r i a n c e s occurred with time (Figure 2 1). At the end of the f o u r t h week, oxygen l e v e l s a t the bottom s t a t i o n were reduced t e m p o r a r i l y below i n f l o w i n g c o n c e n t r a t i o n s , probably due t o high r e s p i r a t i o n r a t e s of the s c a l l o p s as a r e s u l t of the high i n s i t u temperatures., A s i m i l a r oxygen s t r e s s was not e v i d e n t at the mid s t a t i o n , but as noted l a t e r , o ne-half of the s c a l l o p s died d u r i n g IXP2B at t h i s depth. 37 Primary P r o d u c t i v i t y The primary p r o d u c t i v i t y curves f o r Tank A f o l l o w e d a s i m i l a r p a t t e r n to the sta n d i n g s t o c k s , and the maximum values ranged from 110 to 170 ug C l ~ l h r - 4 from the s u r f a c e t o bottom d u r i n g the i n i t i a l bloom (Figure 22). A s i m i l a r p a t t e r n o f primary p r o d u c t i v i t y was e v i d e n t i n Tank B ( F i g u r e 23), but the r a t e s were ca. 3535 g r e a t e r , p a r t i a l l y as a r e s u l t of the higher s t a n d i n g stock c o n c e n t r a t i o n s . > A s i g n i f i c a n t d i f f e r e n c e i n PfiOD occ u r r e d between tanks and s t a t i o n s cn Day 10 as a r e s u l t of the high n i t r a t e c o n c e n t r a t i o n (26 uH K 1~* ) i n the i n f l o w to the s c a l l o p tank on the pr e v i o u s day; t h i s suggested t h a t the phytoplankton p r o d u c t i v i t y was a l r e a d y n u t r i e n t - l i m i t e d by t h i s time. The s t a n d a r d i z e d primary p r o d u c t i v i t y (ASS) f l u c t u a t e d c o n s i d e r a b l y a t a l l s t a t i o n s d u r i n g EXP2A (Figure 24), ranging from t-9 ug C (ug C h l a ) - * hr~* . During the g r a z i n g p e r i o d , the damping of the o s c i l l a t i o n s was minimal, with a decrease i n the range (2.5-7.5 ug C (ug C h l a ) - * h r - 4 ) and an i n c r e a s e i n the p e r i o d {to two weeks). The v a r i a b i l i t y i n ASS between s t a t i o n s was a l s o greater a t t h i s time. The maximum value of ca. 9.0 -ug. C (ug C h l a ) - * h r - * a t the end of the i n i t i a l bloom i n d i c a t e d t h a t although i n s i t u n i t r a t e c o n c e n t r a t i o n s s e r e d e p l e t e d , i n t r a c e l l u l a r n i t r o g e n l e v e l s were not l i m i t i n g primary p r o d u c t i v i t y on Day 8. The s i g n i f i c a n t i n c r e a s e i n ASS on Day 15 a t a l l s t a t i o n s was u n p r e d i c t a b l e , s i n c e at t h i s time, t h e r e was a lower i n f l u x of H03 (plus a temporary i n c r e a s e i n the i n s i t u n i t r a t e l e v e l s ) and Sfi and TEMP were l e s s than on Day 38 12- T h i s i n d i c a t e d t h a t perhaps some s i c r c - n u t r i e n t , such as a v i t a m i n , was l i m i t i n g primary p r o d u c t i v i t y . During the f i f t h week, there was evidence of l i g h t l i m i t a t i o n of primary p r o d u c t i v i t y i n Tank A, with A S S g r e a t e s t at the s u r f a c e and •least a t the bottom,- a t t r i b u t a b l e to the low l e v e l of incoming s o l a r r a d i a t i o n . During most of the post-blccra p e r i o d the highest, s t a n d a r d i z e d p r o d u c t i v i t y r a t e s were at the mid s t a t i o n ; t h i s seems reasonable s i n c e compared to the bottom s t a t i o n , phytoplankton a t the mid depth would have a higher p r o d u c t i v i t y as a f u n c t i o n of S B , while compared t o the s u r f a c e which was r e l a t i v e l y i s o l a t e d p h y s i c a l l y , phytoplankton would have a h i g h e r p r o d u c t i v i t y r a t e as a f u n c t i o n c f the l i m i t i n g n u t r i e n t (s) . . The s t a n d a r d i z e d p r o d u c t i v i t y r a t e i n the s c a l l o p tank was u n s t a b l e , as i l l u s t r a t e d i n F i g u r e 25. The curves e x h i b i t e d undamped o s c i l l a t i o n s of a l a r g e amplitude and c o n s i d e r a b l y out of phase between depths. The high value at the bottom s t a t i o n on Day 10 confirmed that the high i n f l o w N03 en t h e . p r e v i o u s day reduced the l e v e l of n u t r i e n t l i m i t a t i o n . , The average value of A S S during the EXP2B was ca. 5.6 ug C (ug C h l a ) - * hr~* f o r a l l depths; the averages between tanks were s i m i l a r d e s p i t e the high v a r i a n c e s . .. , • ' Composition o f the Phytoplankton Comitucity The bloom i n both tanks was dominated by Skeletonema  costatum ( c a . , 60S by numbers) and T h a l a s s i o s i r a spp. , (20%) with o t h e r diatoms ( Chaetoceros spp. . , Navicula spp. ., And N i t z s c h i a • spp y . ) and nano-f l a g e l l a t e s c o n t r i b u t i n g 39 approximately 10% each.. A f t e r the a d d i t i o n of the o y s t e r s to Tank - A, Chaetoceros sp.,,- became the dominant p h y t o p l a n k t e r . During the f i f t h week, a t h i c k mat of the filamentous b e n t h i c Navicula sp. was removed from the i n f l o w p i p e . However there was ho s i g n i f i c a n t r e c o v e r y c f the phytoplankton stock. N a v i c u l a sp. was a l s o a problem i n Tank B., During the t h i r d week, f l o c c u l e n t clumps o f the a l g a e , which a l s o c o n t a i n e d s c a l l o p f e c e s , f l o a t e d on the s u r f a c e of the tank. The problem worsened and on Day 28, the clumps of Na v i c u l a were removed from the s u r f a c e of Tank B., As i l l u s t r a t e d i n Figu r e 19, t h e r e was an ifflmediate recovery of the phytoplankton s t o c k . Growth of the He r b i v o r e s , C r a g s o s t r e a qiqas, during EXP2A The r e s u l t s of the o y s t e r growth during EXP2A are summarized i n Table 4, which i n c l u d e s the net i n c r e a s e i n the three weight v a r i a b l e s - t o t a l weight (NET!T), meat weight (JSETWH) and s h e l l weight (NETWS) • , Only the percent i n c r e a s e i n meat weight (PEE WM) c o u l d be c a l c u l a t e d s i n c e there was no way of e s t i m a t i n g the p r o p o r t i o n of l i v e s h e l l i n the c u l t c h . The c a l c u l a t i o n o f NETWM and NETWS per oy s t e r per week was based on the number of o y s t e r s g r e a t e r than 2.0 cm., I t was i m p o s s i b l e to ^tiiXa'e«!urate measurements of the l i n e a r dimensions of the However, t h e r e was a c o n s i d e r a b l e range i n s i z e w i t h i n •4«Sfe5n*l^''!' e e f l the c u l t c h . , A few c u l t c h had o y s t e r s with l e n g t h s ".b-fej^ i^ i>-.-5 cm. , The NETHJH:NETfiS r a t i o was a l s o c a l c u l a t e d . • ; There was s i g n i f i c a n t growth of a l l the c u l t c h d u r i n g EXP2A.; The percent i n c r e a s e i n meat weight ranged frcm 10.9% to 36.H6%4 ; ii The highest average r a t e f o r the f o u r s u b s t a t i o n s was 40 25% a t the mid depth, although t h i s mean could net be c o n s i d e r e d s i g n i f i c a n t l y g r e a t e r than the other two depths i n view of the v a r i a b i l i t y between SUBSTN.. The average i n c r e a s e i n meat weight per o y s t e r per week was 0.24 g (SD=-051 g)• The corre s p o n d i n g value f o r s h e l l weight was 0.83 g/zoc/wk> which ranged from 0.5 g/zop/wk to 1.17 g/zoo/wk., There was a l s o a . l a r g e range i n the NETWM:KETBS r a t i o from 0.16 to 0.40., The h i g h e s t average r a t i o and l e a s t v a r i a b i l i t y was 0.32 (SD=.G37) at the bottom s t a t i o n . However, s i n c e t h i s r a t i o i s a f u n c t i o n of the s i z e and number of o y s t e r s per c u l t c h , a l a r g e v a r i a n c e i s not unexpected., h a s t a t a h e r i c i a . during The r e s u l t s of the s u r v i v a l (NSURV) and growth of the s c a l l o p p o p u l a t i o n d u r i n g EXP2B are summarized i n Ta b l e 5. , Less than h a l f of the 32 s c a l l o p s at t h e f o u r mid s u b s t a t i o n s s u r v i v e d ; o f the s c a l l o p s t h a t d i d s u r v i v e , most l o s t weight, except i n Cage 2 which had a 1.1% i n c r e a s e i n t o t a l weight (HGTT). The s m a l l e s t s c a l l o p s i n Cage 1 had the l a r g e s t average percent i n c r e a s e i n length (0.5%) and i n width (2.0%). In comparison, a l l of the s c a l l o p s i n the f o u r cages at the bottom depth s u r v i v e d . . However most s c a l l o p s decreased i n t o t a l weight and the average percent l o s s ranged f r o it 5-0% f o r Cage 9 t o 10.5% f o r Cage 12 (which contained the l a r g e s t s c a l l o p s ) . As mentioned e a r l i e r , the average temperatures dur i n g the g r a z i n g period were 15.6 °C at the bottom depth and 17.2 °C a t the mid depth. However, d u r i n g periods of high SR, the d i f f e r e n c e i n c r e a s e d t o ca,< 5 °C . The s c l a r r a d i a t i o n a l s o Growth of the H e r b i v o r e s , Chlamys EXP2B 41 decreased s i g n i f i c a n t l y with depth., T h e r e f o r e , high v a l u e s of SH or,TEMP, or more, l i k e l y a combination of both v a r i a b l e s , were probably r e s p o n s i b l e f o r the low s u r v i v a l and growth r a t e s . F u r t h e r I n v e s t i g a t i o n of the Oyster Food Chain at an Increased  H e r b i v o r e Density EXP3A was i n i t i a t e d and conducted i n the same manner as EXP,2A, except t h a t the i n s i t u herbivore, d e n s i t y was doubled to 24 , o y s t e r c u l t c h , using 8 s u b s t a t i o n s . The tank became contaminated with zooplankton a f t e r a couple of weeks and EXP3A was r e s t a r t e d on August 20 and conducted f o r on l y three weeks because of the delay. The o y s t e r c u l t c h iwere added t o the tank on Day 6 at t h e a p p r o p r i a t e s u b s t a t i o n s , as o u t l i n e d i n Chapter 2. • .' |. : j j • Dynamics o f t h e Primary Community The f l u s h i n g r a t e remained c o n s t a n t at 0.25 day-* dur i n g the experiment (CV=1%). The r e s u l t s f o r the p h y s i c a l , chemical and primary v a r i a b l e s are i l l u s t r a t e d i n F i g u r e s 26 to 32 and summarized i n Table 6. P h y s i c a l Environment , Although the weather was b e t t e r during EXP3A than EXP2A, the average i n c i d e n t s o l a r r a d i a t i o n was 11% l e s s due to the s h o r t e r daylength (Figure 26). , However, i n terms of the temperature^ there was no s i g n i f i c a n t d i f f e r e n c e i n TEMP between H2 experiments*; The r e d u c t i o n i n s o l a r r a d i a t i o n was compensated f o r by an i n c r e a s e i n the temperature of the inflow t o maintain the 16.2 °G average., As shewn i n : F i g u r e 27, the tank was c o n s i d e r a b l y b e t t e r mixed d u r i n g EXP3A, even d u r i n g the a f t e r n o o n . , • N u t r i e n t fieqime. N i t r a t e c o n c e n t r a t i o n s were c o n t i n u a l l y monitored dur i n g the f i r s t twelve days of the experiments Inflow l e v e l s averaged 21.0 i uH N 1~* (SD=2. OS) which was not . s i g n i f i c a n t l y d i f f e r e n t from the EXP2a average of 21.8 uM N l-» (SD=3.62) f o r the same p e r i o d . The i n f l o w N03 was probably low duri n g the l a s t week of the experiment, as evidenced by, the high . i n f l o w temperatures from Day 11 on, and the subseguent low i n f l o w c o n c e n t r a t i o n of 12.9 uM N l-» on Day 20, I n - s i t u n i t r a t e c o n c e n t r a t i o n s were depleted to valu e s l e s s than 1 uM N 1 _ 1 a f t e r the blcom (Figure 28), although by the end of the experiment, high i n s i t u l e v e l s were recorded at a l l s t a t i o n s u n l i k e EXP2A. Low i n f l o w ammonia c o n c e n t r a t i o n s averaging 0.50 uH N l ~ * c o n t r i b u t e d l i t t l e t o the n i t r o g e n source f o r the production system. The i n s i t u NH3 c o n c e n t r a t i o n a t any depth was not s i g n i f i c a n t l y d i f f e r e n t from the i n f l o w value a t any time d u r i n g the experiment. Phytoplankton Dynamics The: dynamics of the phytoplankton community d u r i n g EXP3A 43 are i l l u s t r a t e d i n Figure 29. Both the standing stock and primary p r o d u c t i v i t y curves e x h i b i t e d damped o s c i l l a t i o n s with approximately a one week p e r i o d . The bloom occurred on Day 4, and d u r i n g the p r e - g r a z i n g p e r i o d , CHIA was 36% higher compared with EXP2A, and the d i f f e r e n c e i n GALA between depths was l e s s , ranging from 13,9 to 16.2 ug C h i a 1~* , During the g r a z i n g p e r i o d (t>6), the phytoplankton stock averaged 7,3 ug C h i a l - i compared with 5.2 ug C h i a 1-* f o r the corresponding p e r i o d i n EXP2A, i n s p i t e of the i n c r e a s e d g r a z i n g p r e s s u r e . However, the phytoplankton stock was p r i m a r i l y Chaetoceros sp. , which was ap p a r e n t l y r e j e c t e d by the o y s t e r s as a s u i t a b l e food source. Oxygen L e v e l s The l a c k of constancy i n the i n f l o s seawater c o n d i t i o n s was a l s o apparent i n the oxygen c o n c e n t r a t i o n (Figure 30), which averaged only 7.04 mg i - 1 with a CV of 10.2%. Although i n s i t u oxygen: l e v e l s f o l l o w e d a s i m i l a r p a t t e r n of damped o s c i l l a t i o n s as EXP2A, the maximum OXY c o n c e n t r a t i o n of 14.1 mg 1 _ 1 was ca. 3.0 mg l - i lower and the period was approximately a week, one-h a l f the d u r a t i o n i n EXP2A., There was no s i g n i f i c a n t d i f f e r e n c e i n oxygen l e v e l s between depths, and a high p o s i t i v e c o r r e l a t i o n was apparent between the pr o d u c t i o n of oxygen and CHLA from two days p r e v i o u s l y . The average value of OXY du r i n g the experiment was 9.92 mg i~ l which r e p r e s e n t e d a 50% decrease i n the pro d u c t i o n of oxygen (OXYN) compared with t i e f i r s t t h r e e weeks of EXP2A. , 44 Primary P r o d u c t i v i t y The primary p r o d u c t i v i t y r a t e s were s i m i l a r between depths throughout the experiment (Figure 31), averaging 27.2 ug. C 1"' h r — 1 , and were a l s o p o s i t i v e l y c o r r e l a t e d with the phytoplankton s t o c k . ,• The s t a n d a r d i z e d primary p r o d u c t i v i t y (ASS) e x h i b i t e d undamped o s c i l l a t i o n s ( F igure 3 2 ) , ranging from 1.2 d u r i n g the p r e - g r a z i n g p e r i o d to 8.8 a t the end o f the experiment. During the g r a z i n g : p e r i o d , ASS sas g r e a t e s t a t the bottom s t a t i o n i n d i c a t i n g t h a t the system was not l i g h t - l i m i t e d . However, the high i n s i t u n i t r a t e c o n c e n t r a t i o n a t the end of the experiment a l s o suggested t h a t another n u t r i e n t , perhaps v i t a m i n B12, was l i m i t i n g primary p r o d u c t i v i t y i n t h i s experiment, as w e l l as Experiment 2., The p a t t e r n of ASS between EXP3A . and EXP2A was very d i f f e r e n t . The i n i t i a l maximum occurred on Day 3 i n EXP3A, and the average value of 2.4 during t h e p r e - g r a z i n g p e r i o d was 25% l e s s than i n EXP2A. During the g r a z i n g p e r i o d , the s t a n d a r d i z e d p r o d u c t i v i t y r a t e averaged 4.3 u g C (ug C h l a ) - 1 h r - 1 , which was a l s o 25S l e s s than the mean f o r t h e corresponding time p e r i o d i n EXP2A., Composition o f jthe. Phytoplankton Community The composition o f the phytoplankton community du r i n g EXP3A was s i m i l a r to EXP2A, with Skeletonemacostatum dominating the bloom and Chaetoceros sp., the dominant phytoplankter d u r i n g the g r a z i n g p e r i o d . Large numbers of n a n o - f l a g e l l a t e s were not found in e i t h e r EXP2A or EXP3A i n c o n t r a s t t o a s i m i l a r c u l t u r e system :(F£=0.25 d a y - 4 ) with no i n s i t u h e r b i v o r e p o p u l a t i o n 45 (Brown and Parsons, 1972). The bicmass of Na v i c u l a sp. on the i n f l o w pipe was l e s s i n EXP3A although there was some growth on the o y s t e r c u l t c h . By the end of the experiment. Tank A was very c l e a r and l a r g e amounts of f e c a l m a t e r i a l were apparent on the bottom of the tank. , Growth o f the O y s t e r s at a Higher S t o c k i n g Density The r e s u l t s o f the oy s t e r growth d u r i n g EXP3A, i n which the s t o c k i n g d e n s i t y was doubled from EXP2A, are summarized i n Table 7. The average change i n HETHJ3 per o y s t e r per week was 0.16 g/zoo/wk (SD=. 159) compared with 0.24 g/zcc/wk (SD=.051) f o r EXP2A. . However, the l a r g e v a r i a b i l i t y w i t h i n s u b s t a t i o n s removed the chance of any s i g n i f i c a n t p r o b a b i l i t y t h a t the growth during EXP3A was l e s s due t o the i n c r e a s e d s t o c k i n g d e n s i t y . The v a r i a b i l i t y was a l s o high between depths and the maximum average v a l u e s a t the bottom s t a t i o n of 0.23 g/zoo/wk (SD=. 178) f o r HETHH and 0.6O g/zoo/wk (SD=.3"76) f o r NETWS were not s i g n i f i c a n t l y g r e a t e r than the s u r f a c e c r mid s u b s t a t i o n s . , The same problem with v a r i a b i l i t y e x i s t e d f o r the NETHMzNETSS r a t i o , which ranged from .03 to 1.00 and averaged .37 (SD=.285) f o r the 24 c u l t c h . T h i s value was higher than the average r a t i o of 0.29 (SD=0.70) during EXP2A, The high e r temperatures during the f o u r t h and f i f t h week of EXP2A may have promoted an i n c r e a s e d growth i n s h e l l weight, p a r t i c u l a r l y a t the s u r f a c e depth which had a HETIHsBSXHS r a t i o of 0.26. 46 F a r t h e r I n v e s t i g a t i o n o f the S c a l l o p Food Chain a t an Increased F l u s h i n g Bate of the System The f l u s h i n g r a t e was s e t at 0.75 day-* f o r Experiment 3B and the;tank seeded a t 1500 hours on J u l y 26, i n the same manner as EXP2B. As o u t l i n e d i n Chapter 2, the s c a l l o p cages were i n t r o d u c e d i n t o Tank B on Day 11 f o r one morth. Dynamics cf -the Primary Community During the experiment, the f l u s h i n g r a t e d i d not remain constant at 0.75 day-* (CV=9.4S) due to problems with the seawater system and hig h sediment loads r e d u c i n g the flow rate through the f i l t e r to the r e s e v o i r - The f l u s h i n g r a t e s sometimes decreased t o 0-6 day-* but were r e a d j u s t e d to 0.75 day -* a t sampling time. The r e s u l t s of EXP3B are i l l u s t r a t e d i n Fig u r e s 33 t o 39 and s t a t i s t i c a l l y summarized i n Table 8. P h y s i c a l Environment r Although the s o l a r r a d i a t i o n was 8% l e s s than i n EXP2B due to d e c r e a s i n g daylength, the v a r i a b l i l i t y i n SE during EXP3B was l e s s (CV=28%) # e s p e c i a l l y at the beginning of the experiment (Figure 33). . During the bloom p e r i o d (Days 1-6), the s o l a r r a d i a t i o n was 15% greater f o r EXP3B than the same p e r i o d i n EXP2B.J , Because of the i n c r e a s e d f l u s h i n g r a t e , the average i n s i t u temperature was lowered to 14.8 °C at a l l depths, which represented a net thermal i n c r e a s e o f 3.4 °C f o r t h i s p r o d u c t i o n system (Figure 34).. The net i n c r e a s e , i n FXP2B was 5.5 °C i n d i c a t i n g t h a t t r i p l i n g the f l u s h i n g decrease i n the i n s i t u temperature at d i u r n a l i n c r e a s e was l e s s than 2.5 °C / : N u t r i e n t fieqjme Inflow n i t r a t e c o n c e n t r a t i o n s averaged 19.3 uM N which was not s i g n i f i c a n t l y higher than EXP2B, and the v a r i a n c e was l e s s (CV=10%). < I n - s i t u c o n c e n t r a t i o n s o f n i t r a t e were again d e p l e t e d by Day 6 and averaged 0.3 uH N I T * , i n the tank with no s i g n i f i c a n t recovery from l i m i t i n g c o n c e n t r a t i o n s d u r i n g the experiment (Figure 35). The average i n f l o w ammonia c o n c e n t r a t i o n was o n l y 0.42 uM N 1 - * . There was no s i g n i f i c a n t i n s i t u change i n NH3, i n d i c a t i n g t h a t a s t e a d y - s t a t e e x i s t e d 'between the uptake of NH3 by the phytoplankton and e x c r e t i o n of NH3 by the s c a l l o p s . Phytoplankton Dynamics  Standing Stock The standing s t o c k , measured as the c h l o r o p h y l l a c o n c e n t r a t i o n , i s i l l u s t r a t e d i n F i g u r e 36. The i n i t i a l bloom peaked on Day 6 c o i n c i d e n t with the d e p l e t i o n of i n s i t u N03. However, a l a r g e r secondary maximum of c a . 40 ug C 1—* h r - 1 o c c u r r e d on Day 10 i n response t o an i n c r e a s e i n the i n f l o w n i t r a t e c o n c e n t r a t i o n . During the g r a z i n g p e r i o d , the phytoplankton stock d i s p l a y e d a s e r i e s of damped o s c i l l a t i o n s and maintained a quasi s t e a d y - s t a t e l e v e l at c a . 30 ug C h i a 1 rate caused a 2.0 °C sampling time. The 48 - * , and there was no s i g n i f i c a n t d i f f e r e n c e between depths. The dynamics of the phytcplanktcn s t o c k at t h i s higher f l u s h i n g r a t e of 0.75 day-* were c o n s i d e r a b l y d i f f e r e n t than CHLA durin g EXP2B (FB=0.25 day-* ) . The phytoplankton stock averaged 23.7 ug C h i a 1-* f o r the t o t a l e x p e r i m e n t a l p e r i o d , approximately three times the average CHLA value d u r i n g EXP2B and d i r e c t l y p r o p o r t i o n a l to the d i f f e r e n c e i n f l u s h i n g r a t e s . During the g r a z i n g p e r i o d , the r a t i o i n c r e a s e d t o 5:1 i n d i c a t i n g t h at the e f f e c t o f the i n c r e a s e d FB i n t h i s experiment dominated the system. The g r a z i n g pressure d i d not cause a decrease i n CHLA, and i n f a c t , the e x c r e t i o n of MH3 by the s c a l l o p s may have enhanced the primary p r o d u c t i v i t y r a t e . , Oxygen l e v e l s The oxygen curves f o r EXP3B (Figure 37) showed a completely d i f f e r e n t p a t t e r n from the p r e v i o u s r e s u l t s i n EXP2B, supported by t h e . r e p r o d u c i b i l i t y between depths. The average OXY c o n c e n t r a t i o n was 11;45 mg l-» d u r i n g EXP3E and there was no d i f f e r e n c e between s t a t i o n s . There were th r e e major d i f f e r e n c e s i n the oxygen c o n c e n t r a t i o n d u r i n g EXP3B compared with EXP2B: f i r s t , the i n i t i a l OXY maximum during the fclcom was 70% l e s s ; second, a s t e a d y - s t a t e l e v e l of oxygen was maintained f o r the d u r a t i o n of EXP3B, e x e m p l i f i e d by the lew average CV of 6.7% d u r i n g the g r a z i n g p e r i o d and a standard d e v i a t i o n which approached the value f o r the i n f l o w ; t h i r d , the net oxygen c o n c e n t r a t i o n (OXYN) was 25% l e s s d u r i n g the p r e - g r a z i n g p e r i o d and 50% g r e a t e r d u r i n g the g r a z i n g p e r i o d . 49 Primary P r o d u c t i v i t y The primary p r o d u c t i v i t y r a t e reached a maximum value of ca . 8 0 ug C l-» h r - 1 on Day 6 and decreased i n a s e r i e s of damped o s c i l l a t i o n s to s t e a d y - s t a t e r a t e s ^(Figure 38). During the experiment, PROD averaged 38.3 ug C 1 _ 1 h r - 1 and there was no s i g n i f i c a n t d i f f e r e n c e between depths. The naximum s t a n d a r d i z e d primary p r o d u c t i v i t y r a t e occurred t h r e e days before the phytoplankton bloom i n E X P 2 B , and i n c o n t r a s t t o EXP3B, ASS was l e s s d u r i n g the g r a z i n g p e r i o d due to the high CHLA c o n c e n t r a t i o n s . The values of ASS were r e l a t i v e l y c onstant at a low r a t e of 1 . 1 ug C (ug C h l a ) - * hr- 1 d u r i n g the g r a z i n g period i n c o n t r a s t t o the high e r average value (6.0 ug C (Ug C h l a ) - 1 hr -*) and g r e a t e r v a r i a b i l i t y d u r i n g EXP2B (Figure 39). Ccmposition of the Phytoplankton Community In ; c o n t r a s t to EXP2B, Skeletonema ccstatum remained the dominant phytoplankter during the experiment. Other diatoms i n s i g n i f i c a n t numbers were N j t z s c h i a sjap... .-. , N a v i c u l a sp.- - and T h a l a s s i o s i r a sp. , and only a few f l a g e l l a t e s were n o t i c e a b l e . M o r e : s i g n i f i c a n t l y , there were no clumps of the f i l a m e n t o u s N a v i c u l a sp. f l o a t i n g on the s u r f a c e of the tank at any time d u r i n g t h e EXP3B. .. Growth of the S c a l l o p s at a Higher F l u s h i n g Rate The r e s u l t s o f the s u r v i v a l and growth of the s c a l l o p p o p u l a t i o n during EXP3B are summarized J i n Table 9. ,, In s p i t e o f the i n c r e a s e d f l u s h i n g i n t h i s experiment, a l l of the s c a l l o p s 50 d i ed at the s u r f a c e s u b s t a t i o n s , approximately one-half d i e d at the mid depth and o n l y one Chlamys d i e d at the bottom depth. Only the s c a l l o p s at the bcttGm s t a t i o n shewed any a p p r e c i a b l e growth duri n g EXP3B. , The maximum percent , i n c r e a s e i n t o t a l weight was the g r e a t e s t i n Cage 9, averaging 16.8% above the i n i t i a l average weight of 16.9 g. However, the l a r g e s t s c a l l o p s i n Cage 12 i n c r e a s e d by only 1.2J a t the bottom depth., The s m a l l e s t s c a l l o p s at the bottom (Cage 8) had the l a r g e s t percent i n c r e a s e of 1.8% i n l e n g t h with a corresponding i n c r e a s e of 0.5% i n width. As pointed out e a r l i e r , the temperature during the g r a z i n g p e r i o d averaged 14.5 °C and t h e r e was no s i g n i f i c a n t d i f f e r e n c e i n TEHP between depths. T h e r e f o r e i t appears t h a t the i n c r e a s e d l i g h t i n t e n s i t y was the primary cause of the 10.0% m o r t a l i t y at the s u r f a c e . Approximately one-half of these s c a l l o p s were dead w i t h i n a week.. , Secondly, the environmental c o n d i t i o n s r e s u l t i n g frcm the i n c r e a s e d f l u s h i n g r a t e provided a f a v o u r a b l e environment f o r the growth of Chlamys at a depth of 1 metre. 51 CHAPSEfi 5., TWO-STAGE CONTINUOUS CUITUBES IN TUBBDLENT 8PWELLING SYSTEMS: DYNAMICS OF THE PBIMABY CCMMONITY AT TWO COMPABATIVE FLUSHING BATES The dynamics of n a t u r a l phytoplanktcn communities i n t u r b u l e n t systems with no g r a z i n g pressure were f i r s t i n v e s t i g a t e d i n a s e t of experiments which compared two constant f l u s h i n g r a t e s of the primary system.. The f l u s h i n g r a t e s i n the d u p l i c a t e primary systems were c o n t r o l l e d a t 0.5 d a y - 1 d u r i n g EXP4A and 1.00 day-* during EXPUB i n t h i s set of experiments.,, During the f i v e week experimental p e r i o d , the r a t e s remained, r e l a t i v e l y c o n s t a n t a t 0.49 day-* <SD=.019) and 1.00 day - i (SD=.001). . However, as a r e s u l t of o u t s i d e i n t e r f e r e n c e with the e x p e r i m e n t a l f a c i l i t i e s cn Day 12, the c e n t r a l sampling tube i n Tank A became angled toward the i n f l o w pipe i n the tank.. Consequently, the apparent 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 v a r i a b l e measurements between the bottom s t a t i o n and the other s t a t i o n s ( s u r f a c e , mid and outflow) i n t h i s tank can be e x p l a i n e d as sampling i n c o m p l e t e l y mixed i n f l o w i n g seawater. ' A f t e r each primary tank was f i l l e d with the f i l t e r e d i n f l o w i n g seawater and the f l u s h i n g r a t e s set, i n i t i a l samples were taken from both tanks.. Then each tank was seeded with 10 l i t r e s o f phytoplankton stock which bad been c o l l e c t e d from the s u r f a c e of E n g l i s h Bay and passed through a s m a l l diameter wire scree n to remove any zooplankton. The experiments were terminated cn Day 35 due to problems with the seawater system i n t a k e a t the I n s t i t u t e . 52 Dynamics of the Primacy Cc maunities at Two Comparative F l u s h i n g Bates Experimental r e s u l t s f o r the two primary tanks (EXP4A and EXP4B) are g r a p h i c a l l y i l l u s t r a t e d i n F i g u r e s 40 to 56 and the data s t a t i s t i c a l l y summarized i n Ta b l e s 10 to 15. In the s t a t i s t i c a l a n a l y s e s , »a' and. ••t* r e f e r t o the f a c t o r s s t a t i o n and time r e s p e c t i v e l y , and the term ' s i g n i f i c a n t ' i n d i c a t e s a s t a t i s t i c a l p r o b a b i l i t y l e v e l of 0.05 unless otherwise s t a t e d . V a r i a b l e s and parameters are sometimes r e f e r r e d t o by t h e i r computer names, and Appendix 1 c o n t a i n s a summary of t h e i r d e s c r i p t i o n and d e r i v a t i o n . . P h y s i c a l Environment I n c i d e n t s o l a r r a d i a t i o n (SB) o s c i l l a t e d c o n s i d e r a b l y from 110r560 l a n g l e y d a y - 1 , averaging c a . , 380 l a n g l e y d a y - 1 (SD=150) d u r i n g the experiments (Figure 40}., There was no s u s t a i n e d p e r i o d o f high s o l a r r a d i a t i o n l e v e l s and i n f a c t , the s i g n i f i c a n c e o f the s e r i a l c o r r e l a t i o n c o e f f i c i e n t s f o r SB i n d i c a t e d a st r o n g f o r c i n g p e r i o d i c i t y to both primary systems A and B (Table 10). The r e s u l t i n g i n s i t u temperatures (TEMP) v a r i e d s i g n i f i c a n t l y with time i n both tanks (Figure 41) and the high average c o r r e l a t i o n s of r(A)=.748 and r(B)=. 804 between the s o l a r r a d i a t i o n and the net temperature i n c r e a s e (TEMPN) p e r s i s t e d a t a s i g n i f i c a n t l e v e l f o r at l e a s t one day i n both tanks, p a r t i c u l a r l y i n Tank A with the lower f l u s h i n g r a t e . The m u l t i p l e c o r r e l a t i o n f o r TEMP and IEBEN with s t a t i o n and time was >0.99, and the temperature i n Tank A averaged 14.6 °C 53 (av SD=1.28) # a net i n c r e a s e of 4.2 °C from the i n f l o w temperature., A p a t t e r n of weekly p e r i o d i c o s c i l l a t i o n s i n temperature and a high c o r r e l a t i o n between s t a t i o n s were s i m i l a r l y apparent i n Tank B, cut at t h i s higher f l u s h i n g r a t e o f 1.0 day— 1, the average temperature and amplitude were reduced to 13.0 «C (av SD=0.77), a net i n c r e a s e of 2.6 °C . Although the average s o l a r r a d i a t i o n decreased s l i g h t l y d u r i n g the n u t r i e n t - d e p l e t e d p e r i o d of the experiments, there was no s i g n i f i c a n t r e d u c t i o n i n the i n s i t u temperatures i n e i t h e r tank; I t should a l s o be noted t h a t during the experiment the temperature and s a l i n i t y o f the i n f l o w i n g seawater were r e l a t i v e l y c o n s t a n t to both tanks at 10.4 °C (av SD=0.40) and 27.3 ppt (SD=0.79) and there was no s i g n i f i c a n t c o r r e l a t i o n of e i t h e r v a r i a b l e with i n c i d e n t s o l a r r a d i a t i o n (Table 10). N u t r i e n t fieqime• Inflow n i t r a t e c o n c e n t r a t i o n s (N03) to both tanks were more v a r i a b l e with time, averaging 18.8 uH N 1 — 1 (C¥=14.5%), due i n part to the c o r r e l a t i o n between N03 and the v a r y i n g t i d a l h e i g h t a t sampling time, as mentioned i n Chapter 4. However, although the t i d a l h e i g h t a t sampling time was h i g h during the f i r s t two weeks o f the experiments, the n i t r a t e c o n c e n t r a t i o n was lower than average due to the presence of a s u r f a c e water mass i n the . v i c i n i t y o f the seawater i n t a k e . T h i s was a l s o d e t e c t e d by the higher i n f l o w temperatures and oxygen l e v e l s during t h i s p e r i o d , and the high c o r r e l a t i o n s between these three v a r i a b l e s are v e r i f i e d i n Table 10., The i n f l o w N03 was a l s o s i g n i f i c a n t l y c o r r e l a t e d with the s o l a r r a d i a t i o n from two days p r e v i o u s l y . 54 Although t h e r e was no s i g n i f i c a n t d i f f e r e n c e i n the i n f l o w n i t r a t e between tanks, n u t r i e n t d e p l e t i o n was apparent by bay 6 a t the 0.5 d a y - 1 f l u s h i n g r a t e i n Tank A with a two day time l a g a t the 1.0 day-i f l u s h i n g r a t e i n Tank B (Figure 42). „. During the p o s t b l o c m p e r i o d , the i n f l o w N03 remained a t the average l e v e l o f c a . , 19 uM N 1-* , but there was no i n s i t u n i t r a t e i n Tank B and t h e presence of s p o r a d i c high c o n c e n t r a t i o n s of n i t r a t e i n Tank A are a t t r i b u t e d to the incomplete mixing. The c o n c e n t r a t i o n of n i t r a t e u t i l i z e d by the primary community was c a l c u l a t e d (NO3D), and i n c l u d e d i n the s t a t i s t i c a l summaries. The c o n t r i b u t i o n o f ammonia and urea as n i t r o g e n sources f o r the primary systems was minimal. There was no s i g n i f i c a n t uptake . of these n u t r i e n t s i n e i t h e r tank .due to the low average i n f l o w c o n c e n t r a t i o n of ammonia (0.4 4 ufl N 1~* ) and urea (0.86 uH U 1~» ) and to the l a r g e v a r i a n c e s w i t h i n and between S t a t i o n s d u r i n g the experiment. Phytoplankton - Dynamics Standing Stock The phytoplankton standing s t o c k was estimated each day as c h l o r o p h y l l a. In Tank A # the i n i t i a l bloom was c o i n c i d e n t with n u t r i e n t d e p l e t i o n on Day 6 (Figure 43) and f o r the d u r a t i o n of the experiment (t=29), the s t a n d i n g s t o c k averaged 18.3 ug C h i a l - 1 i n c l u d i n g the hig h e r value o f 20.5 ug Chi a 1~ 1 a t the bottom s t a t i o n . Although t h e r e was a s i g n i f i c a n t v a r i a n c e i n CHLA with time at a l l f o u r s t a t i o n s (av CV=32»), the c o r r e l a t i o n was poor between the bottom s t a t i o n and the other i j j s i t u 55 s t a t i o n s f o r CHLA, as well as TEMP, N03 and OXY, a f t e r Day 12. .. However the s t a n d i n g stock at the other s t a t i o n s o s c i l l a t e d f a i r l y r e g u l a r l y with a one week p e r i o d , s i t h maxima o c c u r r i n g on Days 17, 24 and 31 and the minima cn Days 21 and 28. „ The dynamics of the phytoplankton bloom e x h i b i t e d s e v e r a l major d i f f e r e n c e s i n Tank B. F i r s t , the i n i t i a l bloom was produced subsequent to the d e p l e t i o n of i n s i t u n i t r a t e on Day 8, due to the low i n f l u x e s of s o l a r r a d i a t i o n and n i t r a t e at t h i s time. The CHLA maximum d i d not occur u n t i l Day 15 except at the bottom s t a t i o n , which had a s i g n i f i c a n t l y higher standing s t o c k from Day 9 to Day 12 due to a problem maintaining the a r t i f i c i a l t u r b u l e n c e a t t h i s time. , Secondly, the standing stock d u r i n g the n i t r a t e - d e p l e t e d p e r i o d (t^27) averaged 40.6 ug C h i a 1-* and there was a s i g n i f i c a n t (P>.01) but s m a l l i n c r e a s e with depth., For the t o t a l experimental p e r i o d , the average standing stock i n Tank B (1.0 d a y - 1 FB) was 32.6 ug C h i a 1~» , e x a c t l y 2.0 times the c h l o r o p h y l l a c o n c e n t r a t i o n i n Tank A (0.5 d a y - 1 FB). T h i r d l y , although the dynamics of the phytoplankton standing stock were c o n s i d e r a b l y d i f f e r e n t between tanks i n the f i r s t few weeks, the t i m i n g of the naxima and minima d u r i n g the j l a s t two weeks were s i m i l a r . However, the st a n d i n g s t o c k i n Tank B e x h i b i t e d a p a t t e r n of damped o s c i l l a t i o n s a f t e r the i n i t i a l blocm compared with the more unstable p a t t e r n of o s c i l l a t i o n s i n Tank A. T h i s was e x e m p l i f i e d s t a t i s t i c a l l y by the s i m i l a r i t i e s i n the v a r i a n c e s between tanks f o r CHLA although the s t a n d i n g stock was twice as l a r c e i n Tank B., 56 Pigment B a t i o s The c o n c e n t r a t i o n s of c h l o r o p h y l l b (CBLE), c h l o r o p h y l l c (CHLC) and c a r o t e n o i d s (CT) and the pigment r a t i o s are summarized i n Table 11 and Table 12, i n c l u d i n g the r a t i o s of the pigments i n the seed p o p u l a t i o n . The c h l o r o p h y l l b : c h l o r o p h y l l a r a t i o (BA) and c a r o t e n o i d : c h l o r o p h y l l a r a t i o (CTA) d u r i n g the experiments are a l s o i l l u s t r a t e d i n F i g u r e 44 and F i g u r e 45., During the n i t r a t e - d e p l e t e d p e r i o d (t=29) , a l l pigments r a t i o s i n both tanks sere s i g n i f i c a n t l y d i f f e r e n t s i t h time, but not between s t a t i o n s . , average pigment r a t i o s f o r t h i s period i n d i c a t e d a decrease i n the BA r a t i o from 0.105 i n the seed p o p u l a t i o n t o 0.086 and 0.042 i n Tanks A and B r e s p e c t i v e l y , as w e l l as l a r g e decreases i n the CA r a t i o . . The average CTA r a t i o s of 1..28 and 1.12 i n the tanks showed l i t t l e ' change from the 1.12 r a t i o f o r the i n i t i a l p o p u l a t i o n . . The m u l t i p l e c o r r e l a t i o n between the pigment r a t i o s and both the independent f a c t o r s TIME and STATIOH was >0.90 f o r both tanks, except f o r the C:A and C:CT r a t i o s which probably r e f l e c t s the poor p r e c i s i o n of the c h l o r o p h y l l c measurements (see S t r i c k l a n d and Parsons, 1972, p.187). Oxygen L e v e l s The oxygen c o n c e n t r a t i o n (OXY) , a f o r c i n g v a r i a b l e as w e l l as a s t a t e - d e t e r m i n e d v a r i a b l e , averaged 7.56 mg l - * (av SD=.675) i n the i n f l o w to both tanks during the e x p e r i m e n t a l p e r i o d . / In Tank A, the OXY maximum and the maximum net i n c r e a s e i n oxygen (OXYK) were not c o i n c i d e n t with the i n i t i a l d e p l e t i o n 57 of n i t r a t e and bloom of phytoplankton ( f i g u r e 46), but occurred on Day 19 ( OXY {19) = 13. 35 mg 1~* ,a=3; GXXN (19) =6. 47 mg 1-* ;a=3) as a r e s u l t of the high i n f l o w n i t r a t e c o n c e n t r a t i o n s and s o l a r r a d i a t i o n from Days 18 to 20- Excluding the bottom s t a t i o n , the average oxygen l e v e l d u r i n g the post-bloom p e r i o d (t=29) was 11.18 mg l - * - r which r e p r e s e n t s a 3.71 mg l - 1 net i n c r e a s e i n oxygen i n Tank A. The v a r i a n c e i n OXY and OXYN was h i g h l y s i g n i f i c a n t with time but not between s t a t i o n s - However, i n Tank B , there was a s i g n i f i c a n t d i f f e r e n c e i n OXY and OXYN between s t a t i o n s , with s m a l l p o s i t i v e d e v i a t i o n s from the grand mean, f o r the s u r f a c e and mid s t a t i o n s and s m a l l negative d e v i a t i o n s f o r the bottom and outflo w s t a t i o n s - The m u l t i p l e c o r r e l a t i o n c o e f f i c i e n t f o r OXY and OXYN with both f a c t o r s remained high at >0.94 (Table 14). , A l a r g e i n c r e a s e i n oxygen d i d occur i n Tank, B subsequent to the i n i t i a l d e p l e t i o n of n i t r a t e on Day 8 ( OXYN(12)=5.65 mg 1-* ;a=4), although two l a r g e r maxima of 5.91 mg l - 1 and 6.35 mg 1-* occurred on Days 26 and 34 r e s p e c t i v e l y (Figure 46). The net; i n c r e a s e i n oxygen i n Tank B was 20'.% l a r g e r than i n Tank A f o r the comparable time peri o d (t>6), averaging 4.44 mg 1- 1 (av SD=0. 193). Oxygen s a t u r a t i o n (SAT) i n c r e a s e d i n both tanks from about 79% to sup e r s a t u r a t e d l e v e l s averaging g r e a t e r than 130% d u r i n g the post-bloom p e r i o d and the a n a l y s i s of va r i a n c e p a t t e r n was s i m i l a r t o the OXY and Q X Y N r e s u l t s f o r both tanks. 58 Primary P r o d u c t i v i t y Primary p r o d u c t i v i t y , i n c l u d i n g an a n a l y s i s of the components, was measured using the r a d i o c a r b o n technique f o r e s t i m a t e s of net p a r t i c u l a t e carbon f i x a t i o n (PfiOD) and exudation of o r g a n i c carbon (IXC), p l u s the oxygen method f o r measurements of gr o s s p r o d u c t i v i t y (PGO), r e s p i r a t i o n (RES) and the r e s u l t a n t net p r o d u c t i v i t y (PNG) , which were con v e r t e d to carbon u n i t s using a p h o t o s y n t h e t i c g u o t i e n t ((P. Q.) of 1.2 and a r e s p i r a t o r y q u o t i e n t (R. Q.) of 1.0. , The.gross p r o d u c t i v i t y r a t e s (PGC) were high i n both Tanks A and B, averaging 220 ug C 1-* h r - 1 and 340 ug C 1~* h r - 1 r e s p e c t i v e l y , f o r the s u r f a c e , mid and bottom s t a t i o n s f o r the ten TIMES (every t h i r d day s t a r t i n g on Day 6). Although there was no s i g n i f i c a n t d i f f e r e n c e i n PGO between s t a t i o n s , t h e r e was a s i g n i f i c a n t v a r i a n c e i n these p r o d u c t i v i t y r a t e s with time, p a r t i c u l a r l y i n Tank ., B i n which the phytcplankton maximum d i d not occur u n t i l Day 15 (Figure 47). The m u l t i p l e c o r r e l a t i o n f o r PGO with TIME and STATION was r e l a t i v e l y poor i n Tank A (r=.78) compared with Tank B (r=.96) due to the de v i a n t bottom s t a t i o n i n Tank A. , A f t e r the f i r s t three weeks th e r e was a h i g h e r c o r r e l a t i o n between tanks. , The r e p i r a t i o n r a t e (RES) averaged 40 ug C 1 _ 1 h r - 1 and 47 ug C l - * h r - 1 d u r i n g EXP4A and EXP4B, and the p a t t e r n s were s i m i l a r with p a r t i c u l a r l y high r a t e s on Day 12 (Figure 48). The average *net p r o d u c t i v i t y ' , based on the oxygen method (PNO) , was ! 82% and 86% of the gross p r o d u c t i v i t y i n Tanks A and B r e s p e c t i v e l y . However* the net p r o d u c t i v i t y r a t e determined by the carbon-14 method (PBOD) , was only a s i s a l l f r a c t i o n of PGO 59 (0.21 i n Tank A and 0.17 i n Tank B) , i n d i c a t i n g t h a t t h e r e was a l a r g e average discrepancy between the two methods of e s t i m a t i n g •net p r o d u c t i v i t y * . As a l s o suggested by other s t u d i e s ( M c A l l i s t e r e t a l . ,1964; Eppley and S l o a n , 1965), PROD appears t o r e p r e s e n t the net f i x a t i o n of p a r t i c u l a t e carbon, t a k i n g i n t o account the l o s s e s o f c e l l u l a r carbon due t c exudation (EXC) as w e l l as r e s p i r a t i o n . ., The »*C p r o d u c t i v i t y r a t e was r e l a t i v e l y c o n s t a n t d u r i n g both experiments (Figure 49) although there was a s i g n i f i c a n t d i f f e r e n c e between s t a t i o n s i n Tank A due to the hig h e r v a l u e s at the bottom s t a t i o n . D a i l y e stimates of P80D were c a l c u l a t e d (PCDY) t o normalize any d i f f e r e n c e s i n s o l a r r a d i a t i o n between days d u r i n g the i n c u b a t i o n period.,, The ra t e of p r o d u c t i v i t y was m u l t i p l i e d by the r a t i o of the t o t a l s o l a r r a d i a t i o n d u r i n g the day to the s o l a r r a d i a t i o n d u r i n g the i n c u b a t i o n p e r i o d (see Appendix 1). The r a t i o n a l e f o r t h i s c o n v e r s i o n f a c t o r was that s i n c e PROD i s a h y p e r b o l i c f u n c t i o n of SR ( C h a p t e r 8) and the p r o d u c t i v i t y r a t e s were measured duri n g the period of maximum SR, d a i l y p r o d u c t i v i t y estimates could be expected t o te p r o p o r t i o n a l t o the lower l i g h t l e v e l s during the remaining e a r l y morning and l a t e a f t e r n o o n p e r i o d s . The r e s u l t i n g estimated f i x a t i o n of p a r t i c u l a t e carbon averaged 0.35 mg C I - 1 dy-* and 0.46 mg C l ~ l d y - 1 i n Tanks A and B, and the r e were no major changes i n the ** C p r o d u c t i v i t y u i t h time (Figure 50).., In t e r e s of d a i l y gross p r o d u c t i v i t y , PGODY, values averaged 2. J9 mg C 1 _ 1 d y - 1 and 3.17 mg C l - 1 dy-* during the experiments, with a aaximum value (a=3) o f 4.21 mg C 1~* dy~* on Day 12 i n Tank B (Figure 51). Values f o r the p r o d u c t i v i t y component v a r i a b l e s were a l s o 60 s t a n d a r d i z e d on a st a n d i n g stock b a s i s ( ug C (ug C h l a ) - 1 h r - 1 ) r e p r e s e n t e d by PGOST, PNGST, BESST, ASS and EXCST. The st a n d a r d i z e d gross p r o d u c t i v i t y (PGOST) o s c i l l a t e d d u r i n g the experiments, although there was a de c r e a s i n g trend with time, p a r t i c u l a r l y i n Tank A (Figure 52).. r As i n d i c a t e d i n Tab l e 13 and Table 14, the average and maximum values of PGOST were higher i n i n Tank A and there was more v a r i a b i l i t y compared with Tank B. A l l the component v a r i a b l e s of PGOST were a l s o g r e a t e r i n magnitude i n Tank A, with average values of 2.4 f o r BESST, 2.0 f o r ASS and 6.5 f o r EXCST, compared with BESS1-1.5, ASS=1.7 and EXCST=6.0 f o r Tank B. The h i g h e s t a s s i m i l a t i o n r a t e s (ASS=7.2 ug C (ug C h l a ) - 1 h r - 1 ) occurred i n both tacks three days before each system reached i t s maximum standing s t o c k l e v e l s d u r i n g the i n i t i a l bloom perio d (Figure 53). During the post-bloom p e r i o d , the s t a n d a r d i z e d net primary p r o d u c t i v i t y remained constant between both STATION and TIHE. „ Although there were only f i v e measurement times f o r the exudation r a t e , EXCST g e n e r a l l y decreased i n both tanks with time and the values were s i g n i f i c a n t l y lower a t the bottom s t a t i o n i n Tank A. The s t a n d a r d i z e d r e s p i r a t i o n r a t e d u r i n g EXE4A and EXP4B wa s s i m i l a r t o BES, with maximum values o c c u r r i n g on Day 12.,, However, i n EXP4B, the highest BESST values were apparent cn Day 6 (Figure 54). • . 6 1 E s t i m a t i o n -of Parameters t o r a Primary P r o d u c t i v i t y Model Since the exudation r a t e was onl y measured every second p r o d u c t i v i t y time, a p r o d u c t i v i t y component a n a l y s i s was based on, t=5, a-3 to e v a l u a t e the parameters i n the f o l l o w i n g p r o d u c t i v i t y sub-^model: Gross P r o d u c t i v i t y = A s s i m i l a t i o n .Respiration. * Exudation or 1 = ASS/PGOST * RESST/EGOST + EXCST/PGOST The r e s u l t s are shown i n Table 15., F i r s t , t h i s a d d i t i v e model seems a good approximation ., o f the e x p e r i m e n t a l r e s u l t s . The estimated gross p r o d u c t i v i t y (ESTPGO) i s c l o s e to 1.00 i n both tanks and 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 ESTPGO with TIME or STATION,/Second, the estimate c f the parameters f o r the component v a r i a b l e s are s i m i l a r between tanks i n s p i t e of the d i f f e r e n c e i n f l u s h i n g r a t e s , with a s s i m i l a t i o n r e p r e s e n t i n g about 20% o f the g r o s s p r o d u c t i v i t y and l o s s e s o f ca- 20% to r e s p i r a t i o n and ca. 60% to exudation. , When the r e s p i r a t i o n and a s s i m i l a t i o n components were c a l c u l a t e d f o r t=10 and a=3, the va l u e s were s i m i l a r , i n d i c a t i n g that these parametric e s t i m a t e s based . on t=5 are re a s o n a b l e . . The a s s i m i l a t i o n f r a c t i o n i n c r e a s e d d u r i n g the f o u r t h and f i f t h weeks of the experiments, p a r t i c u l a r l y i n Tank A, sugge s t i n g t h a t APGO i n c r e a s e d i n response t o high i n f l o w c o n c e n t r a t i o n s . also the exudation f r a c t i o n of gross p r o d u c t i v i t y (EEGQ) was lowest when the N03/CHLA r a t i o was h i g h e s t . Parametric e s t i m a t e s were a l s o c a l c u l a t e d f o r the i n i t i a l s l o p e , ALPHAC ( ug C (ug Chla)~» hr~* (l y / m i n ) - * ) i n the 6 2 h y p e r b o l i c p r o d u c t i v i t y versus l i g h t (PAB) r e l a t i o n s h i p . Since the measurements of the e x t i n c t i o n c o e f f i c i e n t (EXTK) were o f qu e s t i o n a b l e accuracy due to f a u l t y equipment; the s o l a r r a d i a t i o n at depth (PABZC) used i n the c a l c u l a t i o n o f ALPHAC, was estimated using B i l e y * s f o r m u l a t i o n of EXTK (See Chapter 2) i n the f o l l o w i n g e q u a t i o n ; PAEZ ( l a n g l e y minr* ) = (PABZC/240.), * EXP (-EXTK*Z) The average value f o r ALPHAC, 11.0 ug C (ug C h l a ) - 1 h r - 1 ( l y / m i n ) - 1 , was p r e d i c t a b l y much lower than f o r ALPHAG. Maximum ALPHAC values of 30.0 occurred i n both tanks on Day 30 (Figure 55) , a t which time SB and TEMP were below average and N03(IN) above average. Although the st a n d i n g s t o c k and n u t r i e n t f l u x i n Tank B were double the l e v e l s i n Tank A, the standing stock per u n i t o f n i t r a t e was e q u a l . , Therefore i t seems reasonable that t h e r e were 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 ALPHAC between tanks s i n c e both systems had predominantly diatom communities.. The i n i t i a l s l o pe based on gross p r o d u c t i v i t y (ALPHAG) was very s i m i l a r f o r both tanks, averaging 64.3 ug C (ug C h l a ) - 1 h r - 1 ( l y / m i n ) - 1 , alth o u g h i n both cases there was a s i g n i f i c a n t i n c r e a s e i n ALPHAG with depth due to the decrease i n PABZO (F i g u r e 56). The s i g n i f i c a n t v a r i a b i l i t y i n ALPHAG with time was net s u r p r i s i n g s i n c e both ASS and PABZ v a r i e d s i g n i f i c a n t l y with time. A s i m i l a r a n a l y s i s of v a r i a n c e was ob t a i n e d f o r ALPHAC. 63 Composition o f the Phytoplankton Community The s i z e composition o f t h e p h y t c p l a r k t c n community was monitored d u r i n g both experiments using the C o u l t e r Counter. The numbers of p a r t i c l e s were converted i n t o volume c o n c e n t r a t i o n s (microns per ml), as o u t l i n e d i n Sheldon and Parsons (1967), and p l o t t e d as a f u n c t i o n of the p a r t i c l e s i z e , measured as the diameter (microns).. F i g u r e s 57 t o 61 are r e p r e s e n t a t i v e o f the r e s u l t s d u r i n g both the bloom and post^ bloom, p e r i o d s of EXP4A. The f i r s t p o i n t t o note i s the s i m i l a r i t y i n the shape of the volume versus s i z e c u r v e s over time.. The unimodal trend with the maximum volume a t 18.4 microns d u r i n g the bloom ( F i g u r e s 57 and 58) p e r s i s t e d throughout the experiment (Figures 22 to 25) with l i t t l e v a r i a t i o n i n the magnitude over time. Secondly, the s i z e composition was s i m i l a r between s t a t i o n s , and the c o r r e l a t i o n between the C o u l t e r counts and c h l o r o p h y l l a was g e n e r a l l y good except f o r a time l a g i n the p a r t i c l e volumes during the i n i t i a l bloom. The r e s u l t s f o r EXP4B were s i m i l a r t o EXP4A i n most r e s p e c t s , except f o r two f e a t u r e s . The p a r t i c l e volumes d u r i n g the i n i t i a l bloom were h i g h e r on Day 12 than Day 9, and sec o n d l y , the magnitude of the maximum volume per ml i n EXP4B was about twice as l a r g e as EXP4A. Throughout the experiments, the dominant phy t o p l a n k t e r was Skeletonema costatum i n both systems. In EXP4E, the other few s p e c i e s present were mostly diatoms, i n c l u d i n g Chaetoceros decipens (?) , T h a i a s s i o s i r a a e s t i v a l i s (?) and N i t z s c h i a spp. A f i l a m e n t o u s b e n t h i c diatom ( Navicula s|.„ ) was apparent on 64 the s i d e s of the primary p r o d u c t i o n tank, hut the s t a n d i n g stock was low compared with the phytoplankton s t o c k . . In comparison, the previous experiments i n d i c a t e d t h a t production of benthic diatoms was s i g n i f i c a n t i n non-turbulent systems. In EXP4A, there was a g r e a t e r d i v e r s i t y of phytoplankters and a few f l a g e l l a t e s p e c i e s were n o t i c a b l e during the the post-bloom p e r i o d , i n c l u d i n g Gymnodinium .sc., , a Prorocentrum s p e c i e s and some cryptomonads. There was a l s o l e s s N a v i c u l a on the s i d e s of Tank ft than Tank B. These f i n d i n g s are c o n s i s t e n t with previous l a b o r a t o r y and f i e l d r e s u l t s which i n d i c a t e d t h a t systems with lower n u t r i e n t f l u x e s tend to have more phytoplankton d i v e r s i t y , and an i n c r e a s e i n the n u t r i e n t c o n c e n t r a t i o n causes an i n c r e a s e i n the dominance of diatoms. at hi g h f l u s h i n g r a t e s of 2.0 d a y - 1 , most of the phytoplankton community was washed out of the system and the primary community became dominated by benthic diatoms such as the N a v i c u l a sp. (Brown and Parsons, 1972)., 65 CH APTER 6. , THO-STAGE CONTINUOUS CULTURES OF PLANKTONIC  HE8VIVO ROUS POOD CHAINS: DYNAMICS OP T EE PRIMARY COMMUNITY AT VARIABLE FLUSHING BATES A s e t of two-stage continuous c u l t u r e experiments were i n v e s t i g a t e d i n the two p r o d u c t i o n systems . , In t h i s case, the dynamics of the primary communities were examined using c o n t r o l l e d , but v a r i a b l e , f l u s h i n g r a t e s of the system. , In pr o d u c t i o n Tank A, the i n i t i a l f l u s h i n g r a t e (FR) was s e t at 0.25 day-* f o r two weeks d u r a t i o n . . On Days 14 and 28 the f l u s h i n g r a t e s were a l t e r e d t o 0.50 day-* and 0.10 day-* r e s p e c t i v e l y . The experiment i n t h i s tank ended a f t e r 6 weeks due to contamination of the primary system by two herbivorous protozoans, one a h o l o t r i c h c i l i a t e ( D i l e p t u s sp?) and the other a h y p o t r i c h . The experiment i n production Tack E was continued t o Day 49, with the f l u s h i n g r a t e r e s e t f r o a the i n i t i a l r a t e o f 1.00- day-* to 0.50 day-* on Day 41., In the second stage of the p r o d u c t i o n system, the outflow from e i t h e r Tack A or B was fed at d i f f e r e n t r a t e s i n t o the f o u r h e r b i v o r e tanks c o n t a i n i n g the three d e n s i t i e s of o y s t e r s plus cne c o n t r o l . T h i s provided f o u r unique experimental c o n d i t i o n s (Experiments I t o IV) and the experimental design f o r the i n v e s t i g a t i o n of the two-stage continuous c u l t u r e s i s summarized i n Tab l e 16. The r e s u l t s are presented i n Chapter 7. During the experimental p e r i o d , two r e l a t e d a s p e c t s o f primary p r o d u c t i v i t y were i n v e s t i g a t e d . A s e r i e s of p r o d u c t i v i t y versus l i g h t experiments were conducted as a f u n c t i o n of the temperature and the n u t r i e n t s t a t u s of the phytoplankton, to estimate the e f f e c t s of these three v a r i a b l e s 6 6 on the primary p r o d u c t i v i t y of the system. The procedure and r e s u l t s are presented i n Chapter 8 . The primary p r o d u c t i v i t y was a l s o analyzed i n a s e r i e s of enrichment experiments to v e r i f y t h a t some m i c r o - n u t r i e n t was not l i m i t i n g the system. The procedure was s i m i l a r to the other radiocarbon uptake measurements except that the samples from Tank B were e n r i c h e d with e i t h e r G u i l l a r d ^ s F medium, or a v i t a m i n aiix (with no B12) or v i t a m i n B12 only* The l a t t e r two enrichments were made at the same c o n c e n t r a t i o n as the a d d i t i o n of the F medium (Table 17).. Experiments were conducted on two. days of v a r y i n g l i g h t i n t e n s i t y , one at a l i g h t - l i E i t i n g l e v e l and the o t h e r at a l i g h t - s a t u r a t i n g l e v e l . The r e s u l t s i n d i c a t e d t h a t only the B12 enrichment a t the high light i n t e n s i t y produced a s i g n i f i c a n t i n c r e a s e i n the primary p r o d u c t i v i t y r a t e i n comparison to the c o n t r o l . . However, there was no s i g n i f i c a n t i n c r e a s e i n primary p r o d u c t i v i t y on e i t h e r day with the F enrichment which contained the same c o n c e n t r a t i o n of vitamin B12. Therefore i s seems probable that H03 was the primary l i m i t i n g n u t r i e n t d u r i n g these experiments., Dynamics of the Primary Communities at V a r i a b l e F l u s h i n g Bates d u r i n g the Experimental p e r i o d A f t e r each primary tank *as f i l l e d with the f i l t e r e d i n f l o w i n g seawater and the f l u s h i n g r a t e s s et, i n i t i a l samples from each tank were taken., I n t h i s set of experiments, each tank was seeded with 10 l i t r e s of phytoplankton stock from EXP4B so t h a t both experiments would have s i m i l a r i n i t i a l primary 67 communities, composed mainly of Skeletccema costatum p l u s a few other diatoms and f l a g e l l a t e s * R e s u l t s of the experiments (EXP5A*EXP5B) are i l l u s t r a t e d i n F i g u r e s 62 to 90, with s t a t i s t i c a l summaries i n T a b l e s 18 to 23., In the f o l l o w i n g d i s c u s s i o n of EXP5A, P e r i o d * s 1, 2 and 3 r e f e r t o the 0.25 d a y - 1 , 0.50 day—* , and 0.10 day-* f l u s h i n g r a t e s r e s p e c t i v e l y . , P h y s i c a l Environment During the f i r s t s i x weeks, ahich i n c l u d e s t h e t o t a l e xperimental period f o r Tank A and the 1.0, d a y - 1 f l u s h i n g r a t e per i o d i n Tank B, the i n c i d e n t s o l a r r a d i a t i o n averaged 400 l a n g l e y day-* (SD=106). As i l l u s t r a t e d i n Figure 62, the means and; v a r i a n c e s f o r SR were very d i f f e r e n t between the three p e r i o d s of v a r i a b l e f l u s h i n g r a t e s i n EXP5A, aver a g i n g 500 l a n g l e y dayr* (SD=15) during Period 1, 340 l a n g l e y day-* (SD=132) f o r the second p e r i o d and 380 l a n g l e y day-* (SD=49) du r i n g the t h i r d p e r i o d (Table 18). The ccmhinaticn of the v a r i a b i l i t y i n s o l a r r a d i a t i o n and f l u s h i n g r a t e r e s u l t e d i n average net temperature i n c r e a s e s (TEHFN) of 6.7 °C , 3.8 °C , and 8.8°C during the three two-week p e r i o d s i n EXP5A. The l a r g e v a r i a b i l i t y i n TEHP during the experiment i n Tank A (Figure 63) was due to t h e c o i n c i d e n c e of a r e i n f o r c i n g e f f e c t of SB with the a l t e r a t i o n i n flow r a t e , p a r t i c u l a r l y d u r i n g Period 2, when the FB was i n c r e a s e d t o 0.50 day-* (with a subsequent decrease i n TEMP) and SB was lower than average., Temperatures reached a * EXP4B was terminated two days before t h e . s t a r t . o f Experiment 5 68 maximum of -2-1.9 ° C d u r i n g the 0.10 day-* Ffl and averaged 19.8 °C , compared with 18.7 °C a t the 0.25 day-* FB and 16.0 day-* a t the 0.50 day-* FB. The temperature averaged 18.1 °C during EXP5A, and although the c o r r e l a t i o n between the f o u r i n s i t u s t a t i o n s was high (r=.994), there was a s t a t i s t i c a l l y s i g n i f i c a n t but s m a l l (0.6 °C ) decrease i n TEMP with depth (Table 20). The temperature i n Tank B during the same p e r i o d (t=1,41) averaged 15,0 °C , with l e s s v a r i a b i l i t y with time (CVf6.1%)* although there was a l s o a s i g n i f i c a n t decrease of 0.3 °G i n TEMP with depth. The temperature during the l a s t week of EXP5B (FR=0.50 day-* ) remained at the average v a l u e . The s a l i n i t y was e s s e n t i a l l y c o n s t a n t at 27.2 ppt (SD=0.92) durin g both experiments. N u t r i e n t Regime Inflow n i t r a t e t o both systems was s i m i l a r but extremely v a r i a b l e with time, averaging 16.5 uM N 1~* (av SD=8.80). ; As i l l u s t r a t e d i n F i g u r e 61 , there was a d e c r e a s i n g trend i n the i n f l o w n i t r a t e c o n c e n t r a t i o n f o r the f i r s t t h r e e weeks, i n c r e a s i n g t o l e v e l s g r e a t e r than 20 uM N 1 - * d u r i n g the remaining p e r i o d . , The i n f l o w N03 c o n c e n t r a t i o n s d u r i n g the t h r e e p e r i o d s cf EXP5A averaged 14.3 uM N 1 ~ * (SD=2.91), 14.1 uM N 1-* (SD=7.70) and 21 . 9 uM N 1~* (SD=1.24) r e s p e c t i v e l y . The low i n f l o w c o n c e n t r a t i o n s during the t h i r d week could be p a r t l y a t t r i b u t e d t o the f a c t that the sampling time c o i n c i d e d with low t i d e . ; As d e s c r i b e d i n Chapter 5, t h i s caused an underestimation i n the i n f l o w c o n c e n t r a t i o n cn a d a i l y b a s i s . An a l g o r i t h m was designed to p a r t i a l l y compensate f o r the discrepancy. A t i d a l r a t i o was c a l c u l a t e d based on the amount of time during the day t h a t the t i d a l h e i g h t was above the h e i g h t at sampling time t o the amount of time per day t h a t the t i d a l h e ight was below the h e i g h t a t sampling time; t h i s f a c t o r was then a p p l i e d t o the n i t r a t e c o n c e n t r a t i o n a t sampling time t o estimate a r e v i s e d d a i l y i n f l o w n i t r a t e c o n c e n t r a t i o n , TN03(IN)., The r e s u l t s i n d i c a t e d t h a t the i n f l o w n i t r a t e value of 16.6 utl N l - 1 averaged f o r t=1,41 i n c r e a s e d to 19.0 uH N 1-* f o r the same time p e r i o d when the temporal e f f e c t o f the t i d e upon sampling was taken i n t o account. , However, no f a c t o r was in c l u d e d to account f o r the i n c r e a s e i n n i t r a t e c o n c e n t r a t i o n with t i d a l h e i g h t , s i n c e the t i d a l amplitude and r a t e of change i n N03 with t i d a l h eight v a r i e d d u r i n g the experimental p e r i o d . , So the r e v i s e d e s t i m a t e s of TN03 probably s t i l l underestimated the a c t u a l average i n f l o w n i t r a t e c o n c e n t r a t i o n . In Tank . A, the d e p l e t i o n of n i t r a t e occurred by Day 5 a t the 0.25 day- 1 f l u s h i n g r a t e , and there *as no i n i n s i t u r e c o v e r y of s i g n i f i c a n t N03 f o r the remainder of the experiment. The n e t uptake of n i t r a t e {N03N) by the primary community i n c r e a s e d during the experiment, averaging S.3 uH N l " 1 , 14. 1 uM ; N l - 1 and 21.9 uH N 1~* f o r the t h r e e p e r i o d s ; the corresponding values based on the t i d a l c o r r e c t i o n f a c t o r , TNQ3N, were 12.0 uH N l - 1 , 16.3 uM N 1-* and 24.1 uH N l - 1 . N i t r a t e d e p l e t i o n d i d not occur u n t i l Day 7 i n Tank B (Ffi=1.0 d a y - 1 ) and s i g n i f i c a n t c o n c e n t r a t i o n s (>2 uK N l - 1 ) of n i t r a t e were apparent on Days 12 and 13. The tank was very c l e a r at t h i s time and much of the phytoplankton s t o c k had sunk to the benthos, i n s p i t e of the i n s i t u c i r c u l a t i n g pumps. , However 7 0 Skeletonema costatum was s t i l l the dominant ph y t o p l a n k t e r . As i n Experiment 4, i n f l o w ammonia and urea c o n c e n t r a t i o n s were low (<1 uM 8 1~* ) d u r i n g the experiments. Phytoplankton Dynamics  Standing Stock The i n i t i a l phytoplankton blooms were c o i n c i d e n t with n u t r i e n t d e p l e t i o n i n both Tanks A and E (Figure 65) and were o f a s i m i l a r magnitude (35-40 ug C h i a 1-* ).-, The c h a r a c t e r i s t i c minimum i n CHLA f o l l o w i n g n u t r i e n t d e p l e t i o n was apparent by Day 9 i n Tank A and by Day 12 i n Tank B. In Tank A, the CHLA l e v e l s t a b i l i z e d at ca. . 8.9 ug C h i a 1~* during the l a s t three days of • the 0.25 day-* F R p e r i o d . ,. a f t e r the f l u s h i n g r a t e was doubled to 0.5 day-* on Day 14, the phytoplankton i n c r e a s e d to c a . , 21 ug C h i a 1~ 1 and r e s t a b i l i z e d a t 17.1 ug C h i a 1 -* from Days 19 t o 22. T h i s was approximately double the s t e a d y - s t a t e value d u r i n g the f i r s t p e r i o d . The l a r g e i n c r e a s e i n the phytoplankton stock during the remaining 6 days of the second p e r i o d (FR=0.5G day -* ) was s i g n i f i c a n t l y c o r r e l a t e d with the l a r g e p o s i t i v e t rend i n the i n f l o w n i t r a t e c o n c e n t r a t i o n from Day 21 t o Day 28 and the high i n c i d e n t s o l a r r a d i a t i o n from Days 21 t o 23. The r e s u l t s i n d i c a t e d t h a t there was a 2 day l a g between the more f a v o u r a b l e f o r c i n g c o n d i t i o n s f o r p r o d u c t i v i t y and the r e s u l t a n t i n c r e a s e i n phytoplanktcit stock, and by the end o f - t h e second peri o d i n Tank A, the stock l e v e l s had reached 45 ug C h i a 1-* . A f t e r the FR was lowered to 0.10 day-* on Day 28, the phytoplankton stock decreased t o c o n c e n t r a t i o n s between 71 15-20 ug Chi a 1-* , before approaching near-zero v a l u e s a t the end of the experiment due to the contamination c f the primary tank by protozoans. During the n u t r i e n t - d e p l e t e d p e r i o d i r Tank B (t>6), the phytoplankton stock reached a s t e a d y - s t a t e value from Days 19-22 which was s i m i l a r to Tank A, although the FB was twice as high as Tank A. However, a f t e r the i n c r e a s e i n incoming N03 and SB a t t h i s time, the phytoplankton stock doubled by Day 23 and reached maximum l e v e l s of ca., 60 ug C h i a 1-* , except at the outflow s t a t i o n which was s i g n i f i c a n t l y lower f o r some reason. The phytoplankton stock d i s p l a y e d a s e r i e s of damped o s c i l l a t i o n s f o l l o w i n g t h i s bloom, d e c r e a s i n g to a l e v e l of ca. 30 ug C h i a h » at the end of the 1.0 day-* Ffi p e r i o d . , The s t a n d i n g s t o c k remained a t a s i m i l a r c o n c e n t r a t i o n i n Tank B d u r i n g the 0.5 day-* FB (t=42,49). There was a small s i g n i f i c a n t i n c r e a s e i n CHLA with depth i n both tanks (Table 20 and T a b l e 21). Pigment B a t i o s The c o n c e n t r a t i o n of CHLB, CHLC, and c a r o t e n o i d (CT) pigments are summarized i n Tables 18 and 19. A l i the accessory pigments and the c a l c u l a t e d pigment , r a t i o s were s i g n i f i c a n t l y v a r i a b l e with time although g e n e r a l l y not d i f f e r e n t between s t a t i o n s . , In Tank A, a f t e r n u t r i e n t - d e p l e t i o n had occurred d u r i n g the 0.25 d a y - 1 FB p e r i o d , t h e r e was a s i g n i f i c a n t i n c r e a s e i n the BA r a t i o (Figure 66).., However, by the end of the second p e r i o d , CHLB c o n c e n t r a t i o n s were reduced to zero a t t h i s higher FB., CHLB again i n c r e a s e d during P e r i o d 3, 7 2 c o n t r i b u t i n g to an e x p o n e n t i a l i n c r e a s e i n the BA r a t i o . , The CTA r a t i o i s i l l u s t r a t e d i n F i g u r e 67 and the c o r r e l a t i o n between the CTA and BA r a t i o was high f o r both tanks. During ' the f i r s t s i x weeks of EXP5B (FE=1.00 day-* ), t h e r e was an e x p o n e n t i a l decrease i n the E A r a t i o , except f o r an i n c r e a s e to ca. 0.1 .from Day 16 to 22, which was c o i n c i d e n t with the low i n f l o w n i t r a t e c o n c e n t r a t i o n s . Oxygen l e v e l s Inflow oxygen c o n c e n t r a t i o n s (OXY) averaged 7.26 nag 1~ 1 (av SD=.835) f o r both tanks d u r i n g the f i r s t s i x weeks. The changes i n i n s i t u oxygen l e v e l s d u r i n g the experiments are i l l u s t r a t e d i n F i g u r e 68., In both t a n k s , OXY maxima were c o i n c i d e n t with the i n i t i a l phytoplankton bloom, and i n Tank A, the 13,63 mg l - 1 average on Day 5 was the maximum value d u r i n g • the experiment. , There was a l s o a s i g n i f i c a n t d i f f e r e n c e i n oxygen between s t a t i o n s i n both tanks. In Tank A, t h i s was p a r t i c u l a r l y e v i d e n t during the 0.10 day-* FH p e r i o d . To compensate f o r the v a r i a b i l i t y i n the i n f l o w oxygen c o n c e n t r a t i o n , the net oxygen i n c r e a s e (OXYN) was c a l c u l a t e d f o r each i n s j t u s t a t i o n . The c o r r e l a t i o n between OXYN and CHLA was high (r=.830), p a r t i c u l a r l y with a one day time l a g f o r CHLA (r=.888)• , E x c l u d i n g the bottom s t a t i o n which was s i g n i f i c a n t l y lower, OXYN reached an average maximum c f 6.99 mg l - * on Day 29, which represented an oxygen c o n c e n t r a t i o n of 13.21 mg l ~ l and an oxygen s a t u r a t i o n l e v e l of 160%. In Tank E, the average value of OXY was o n l y 1.00 mg 1-* h i g h e r f o r t=1,41 and the maximum on Day 32 was not much l a r g e r than f o r Tank A. The c o r r e l a t i o n 73 between OXIN and CHLA f o r the same time perio d swas a l s o high i n Tank B (r=.812), but with no time l a g . Oxygen s a t u r a t i o n l e v e l s were s i m i l a r t o Tank A. , Primary P r o d u c t i v i t y R e s u l t s from the primary p r o d u c t i v i t y measurements are summarized i n Taisles 20 and 21., The number cf TIMES (days) used i n the a n a l y s i s was eleven, represented by every t h i r d day from Day 6 as i n EXP4A and EXP4B » . The gross p r o d u c t i v i t y r a t e s i n Tacks A and B are i l l u s t r a t e d i n F i g u r e 69. . In both cases there was a s i g n i f i c a n t v a r i a b i l i t y i n gross p r o d u c t i v i t y with time s i n c e PGO i s a f u n c t i o n of CHLA. However, i n Tank ft, the uaximum r a t e occurred on Day 4, one day before the CHLA maximum, while i n Tank B the . i n i t i a l PGO maximum was c o i n c i d e n t with the CHLA maximum on Day 7. A l a r g e secondary maximum of 460 ug C ..Ir'1 •hr-'1 a l s o occurred i n Tank B on Day 33, with an estimated d a i l y value (PGQDY) of 3*83 mg C 1~ 1 d y _ 1 . There were no s i g n i f i c a n t d i f f e r e n c e s between s t a t i o n s f o r any of the p r o d u c t i v i t y v a r i a b l e s and the average gross p r o d u c t i v i t y d u r i n g EXP5A and EXP5B was 160 ug C 1 - 1 hr-* and 304 ng C l ~ l h r - 1 r e s p e c t i v e l y . The pa t t e r n between PGO and PGODY was s i m i l a r d u r i n g the experiments (r(A)=.96; r (B)=„98) , except the gross p r o d u c t i v i t y on a d a i l y b a s i s decreased d u r i n g the secondary bloom (Figure 70). The r e s p i r a t i o n r a t e (RES) was r e l a t i v e l y Constant duri n g both 1 The d a t a f o r Day 15 i s missing f o r a l l p r o d u c t i v i t y v a r i a b l e s i n Experiment 5. 74 experiments, averaging ca. , 42 ug C 1~* .hr-*, and o n l y i n Tank B was t h e r e a marginal s i g n i f i c a n t d i f f e r e n c e i n EES with time (Figure 71), The net p r o d u c t i v i t y based cn the oxygen method (PNO) was h i g h l y c o r r e l a t e d with PGO i n both tanks (r>. 97) and the ; r a t e based on the r a d i o c a r b o n method (PROD) was a l s o s i g n i f i c a n t l y c o r r e l a t e d with PGO and PHO (Figure 72). The c o r r e l a t i o n was g r e a t e r i n Tank A (av £(&)=.65) than f o r Tank B (av r (B) =.47) . The average PROD r a t e s during the experiments were 61. ug C l " " * h r - * and 101 ug C l - 1 h r - 1 i n the two tanks, which represented d a i l y net p r o d u c t i v i t y r a t e s of 0.51 mg C 1-.* dy-* and 0.84 mg C 1~* dy~* . The changes i n PCDY with time are i l l u s t r a t e d i n F i g u r e 73. , The e f f e c t of the v a r i a b l e f l u s h i n g r a t e s on primary p r o d u c t i v i t y was analyzed by comparing the p r o d u c t i v i t y v a r i a b l e s s t a n d a r d i z e d per u n i t of CHLA. , The r e s u l t i n g PGOST, RESST and ASS curves are i l l u s t r a t e d i n F i g u r e s 74 to 76,, Maximum s t a n d a r d i z e d gross p r o d u c t i v i t y r a t e s of a t l e a s t 20.7 ug C (ug C h l a ) - * h r - * were a t t a i n e d i n Tank A subsequent to the i n i t i a l phytoplankton bloom, and secondary maxima were a l s o apparent on Day 21 d u r i n g P e r i o d 2 (FR=0.50 day-* ) and on Day 39 d u r i n g Period 3 (FR=0. 10 day-* ) when the s t a n d i n g stock l e v e l approached z e r o , ^he p a t t e r n f o r PGOST i n Tank B was somewhat d i f f e r e n t . . During the f i r s t two weeks, the s t a n d a r d i z e d gross p r o d u c t i v i t y *as r e l a t i v e l y c o n s t a n t , ranging from ca., 10-15 ug C (ug C h l a ) - * hr~* . . Only during the second two-week p e r i o d was the c o r r e l a t i o n high between the two tanks f o r PGOST, although the v a r i a b i l i t y with time was again l e s s i n Tank B. During the t h i r d two-week p e r i o d , EGOST s i g n i f i c a n t l y 75 i n c r e a s e d t o a maximum of ca. 20 ug C (ug C h l a ) - 1 h r - 1 i n Tank B, while the average values remained a t c a . 8 ug C (ug C h l a ) - * h r ~ l i n Tank a u n t i l the i n c r e a s e on Day 39. These maximum va l u e s i n both tanks are g r e a t e r tban the high Pmax's found i n Tokyo Bay, a l s o d u r i n g a Skele to ne ma c p s t a t a m bloom (see Parsons and Takahashi, 197 33).= The s t a n d a r d i z e d r e s p i r a t i o n r a t e (RESST) was more v a r i a b l e d u r i n g EXP5A (Figure 75) , e s p e c i a l l y d u r i n g the bloom p e r i o d when c a . „. 45% of t h e gross p r o d u c t i v i t y was l o s t to r e s p i r a t i o n compared with ca. 13% f o r Tank B (Table 2 2 ). During the second p e r i o d o f EXP5A, RES ST decreased t o a low r a t e of 1.5 ug C (Ug C h l a ) - * h r - 1 , the same value f o r EXP5B durin g the c o r r e s p o n d i n g time p e r i o d . , a f t e r the PR was reduced to 0.1 day-* i n Tank a, RESST i n c r e a s e d by 75% while the s t a n d a r d i z e d r e s p i r a t i o n r a t e i n c r e a s e d by on l y 20% during p e r i o d 3 i n Tank E. The s t a n d a r d i z e d net p r o d u c t i v i t y r a t e (ASS) was c h a r a c t e r i z e d by damped o s c i l l a t i o n s d u r i n g P e r i o d 1 i n EXpSA (Figure 76), averaging 6.0 ug C (ug C h l a ) - 1 far-1 . The v a r i a b i l i t y i n Tank B was l e s s even even though the magnitude was g r e a t e r at 6.5 ug C (ug C h l a ) — * h r - 1 . The a s s i m i l a t i o n r a t e s were t h e the lo w e s t ( 2.5 ug c (ug C h l a ) - * hr~* ) duri n g P e r i o d 2 i n both tanks. , The r a t e i n c r e a s e d i n Tank B on Day 27 i n response to the l a r g e i n c r e a s e i n the i n f l o w n i t r a t e c o n c e n t r a t i o n . „• The r a t e a l s o i n c r e a s e d i n Tank a d u r i n g P e r i o d 3 i n s p i t e of the f i v e - f o l d decrease i n FJB. A c l o s e examination of ass as a f u n c t i o n of, STATION i n Tank B (Figure 76) suggested two i n t e r e s t i n g f e a t u r e s . The l i n e a r i n c r e a s e i n i n f l o w N03 from c a . 3 uM N l ~ l on Day 20 t o c a . 20 uMN 1~* by . Day 24 76 f a i l e d .to a l l e v i a t e the n u t r i e n t - l i m i t e d s t a t e of the phytoplankton by Day 24. However, the system had become l i g h t -l i m i t e d by Day 27, i n d i c a t e d t y the high a s s i m i l a t i o n r a t e at the s u r f a c e compared with the bottom s t a t i o n . By Day 33, the phytoplankton stock appeared t o become n i t r a t e - l i m i t e d again.. E s t i m a t i o n of Parameters f o r j Primary P r o d u c t i v i t y Model ft p r o d u c t i v i t y component a n a l y s i s s i m i l a r to the one o u t l i n e d i n Chapter 5 was used t o e v a l u a t e the p r o p o r t i o n o f gross p r o d u c t i v i t y represented ty a s s i n i l a t i o n , r e s p i r a t i o n and e x u d a t i o n , , The r e s u l t s are shown i n Table 23. , The estimated g r o s s p r o d u c t i v i t y (ESTPGO) was 6% h i g h e r than 1.00 i n Tank A and 16$ lower than expected i n Tank B. i n the case of EXP5B, the r a t i o o f exudation t o gross p r o d u c t i v i t y (EPGO) was suspect. The e s t i m a t e s of BPGO ( r e s p i r a t i o n : gross p r o d u c t i v i t y ) and APGO ( a s s i m i l a t i o n : g r o s s p r o d u c t i v i t y ) were C.15 and 0.36 r e s p e c t i v e l y , r e g a r d l e s s of whether the estimates were based on the p r o d u c t i v i t y d a t a f o r the t o t a l experimental p e r i o d (t=11) or only the times when EXC was measured (t=5). T h e r e f o r e EPGO was probably c l o s e r t o 0,50, On the other hand, i f the values f o r BPGO and APGO were based on the t o t a l experiment i n EXP5A, then ESTPGO c l o s e l y approximated the expected value of 1.00. Summarizing,, i n EXP5ft r e s p i r a t i o n and exudation each represented ca. 30% of t h e gross p r o d u c t i v i t y with c a . , 40% a t t r i b u t e d t o a s s i m i l a t i o n ; i n EXP5B, the l a r g e s t p r o p o r t i o n of gross p r o d u c t i v i t y was channeled through exudation ( ca. 50% ) , the a s s i m i l a t i o n component decreased s l i g h t l y to c a . 35% and the r e s p i r a t i o n f r a c t i o n was 15%, about h a l f the value i n EXP5A., 77 Values f o r ALPHAC ( ug C (ug C h l a ) - * hr-* ( l y / m i n ) - * ) , the i n i t i a l s l o p e i n the **C p r o d u c t i v i t y versus l i g h t (PAH) r e l a t i o n s h i p , were a l s o estimated from the ASS and PA8ZC data as i n Chapter 5.,, In EXP5A, ALPHAC reached a maximum of ca. 60 ug C (ug C h l a ) - 1 hr~* ( l y / m i n ) - * at the bottom s t a t i o n and decreased t o an average value of 11.7 ug C (ug C h l a ) - 1 h r - 1 ( l y / m i n ) — 1 during P e r i o d 3 ( f i g u r e 77). The average value f o r EXP5A was 14.0 ug C (ug C h l a ) - * h r - * ( l y / m i n ) - * compared with 15.7 ug C (ug C h l a ) - * hr-* (ly/min) -* f o r EXP5B. The lowest e s t i m a t e s of ALPHAC occurred on Cay 2 1 i n both tanks when the i n f l o w i n g N03 was very low and SB was h i g h . The c o r r e s p o n d i n g e s t i m a t e s of. the i n i t i a l slope based on the gross p r o d u c t i v i t y (ALPHAG) are i l l u s t r a t e d i n F i g u r e 78. Composition of the Phytoplankton Community The e v o l u t i o n of the phytoplankton communities i n terms of s i z e 1 composition are i l l u s t r a t e d i n F i g u r e s 79 to 84 f o r EXP5A and F i g u r e s 85 to 90 f o r EXP5E.„ The s i x times or days were r e p r e s e n t a t i v e of the s t r u c t u r e of the primary community approximately one week a f t e r each change i n the f l u s h i n g r a t e i n EXP5A. The co r r e s p o n d i n g r e s u l t s from Tank E were a l s o i n c l u d e d as a comparison of a system with a high constant f l u s h i n g r a t e . During the i n i t i a l bloom period i n EXP5A (Figures 79 and 80), the maximum volume-of • p a r t i c l e s ' was found at the 22.6 micron s i z e on Day 6; with the onset of n u t r i e n t - d e p l e t i o n , the decreased maximum volume s h i f t e d to the 14.3 u diameter s i z e by Day 12. By comparison, the maximum volume i n Tank B was evident 78 a t the same diameter of 22.6 u on Days 6, 9 and 12 (Figures 85 and 86). The l a t e r t i ming of the maximum p a r t i c l e volume on Day 9 f o l l o w e d the same trend as the phytoplankton stock measured as CHLA. .. During P e r i o d 2 (Days 15-28), the s i z e composition i n Tank A s h i f t e d to a bimodal d i s t r i b u t i o n with maximum volumes at the 9.0 u and 18.5 u s i z e s ( F i g u r e s 81 and 82). However, the phytoplankton i n EXP5B r e t a i n e d a unimodal s i z e d i s t r i b u t i o n , although the diameter of the maximum volume had s h i f t e d to 11.3 u by Day 24 ( F i g u r e s 87 and 88). The c e l l diameter of the maximum volume i n c r e a s e d again to 14.3 u by Day 39 ( F i g u r e s 89 and 90). During P e r i o d 3 i n EXP5A, the phytoplankton volume c o n c e n t r a t i o n returned to a unimodal s i z e d i s t r i b u t i o n with the maximum volume a t 11.3u, although the magnitude had decreased s i g n i f i c a n t l y by Day 39 (Figures 46 and 47). t Skeletonema costatum was the dominant phytoplankter f o r the d u r a t i o n of FXP5B even on Day 12 when the system was i n i t i a l l y d epleted of n u t r i e n t s and the phytoplankton stock was a t a minimum, irhe other two main diatom s p e c i e s i n Tank B were Chaetoceros decipens J7J. and N i t z s c h i a c l o s t e r i u m (?) , although some B h i z o s o l e n i a were a l s o apparent at the end of the 1.0 day-* FR ., The phytoplankton composition during EXP5A was q u i t e d i f f e r e n t from EXP5B. Although present i n s i g n i f i c a n t numbers, Skeletonema costatum was not the dominant p h y t o p l a n k t e r . A Chaetoceros s p e c i e s (compressum?) was t h e dominant p h y t o p l a n k t e r a f t e r the i n i t i a l bloom and T h a l a s s i o t h r i x and N i t z s c h i a were a l s o present i n s i g n i f i c a n t numbers. Throughout the experiment. Tank ft had a much h i g h e r d i v e r s i t y , with more s p e c i e s of diatoms 7 9 and a v a r i e t y of n a n o - f l a g e l l a t e s . , By the end o f EXP5A, the s p e c i e s l i s t , a l s o i n c l u d e d fihizpsclenia d e l i c a t u l a , a u n i c e l l u l a r Chaetoceros , cryptomomads ( Cryptomonas sp. , ) and { O x h y r r i s sp.. ). I t should be noted t h a t the s p e c i e s composition, as w e l l as c e l l numbers, i n Tank A would have been a f f e c t e d by the presence of the predatory c i l i a t e s which •contaminated* the primary system d u r i n g the l a s t weejk of the experiment. , 80 CHAPTEB 7. TWO-STAG! CO HUM OOPS COLT OSES OF PLANKTONIC HEfiBIVOBQOS FOOD CHAINS: G.BQ1TH OF THE HERBIVOEES Experimental Design Growth of t h e s e s s i l e * p l a n k t o n i c * h e r b i v o r e , C r a s s o s t r e a gjgas •, was i n v e s t i g a t e d i n a two-stage c u l t u r e system (Figure 5) using the outflow from e i t h e r primary tank A or B as a continuous source of phytoplankton and oxygen to the four h e r b i v o r e tanks. Four o y s t e r experiments (EXFI t o EXPIV) of one week d u r a t i o n were conducted f r o n Days 18 to 50 during the post-bloom p e r i o d o f the primary t a n k s . . The f o u r experiments d i f f e r e d i n the source of the i n f l o w (Tack A or B) and i n the f l u s h i n g r a t e of the herbi v o r e tanks (Fi= 1.0 day -* or 2.0 d a y - 1 ) to compare v a r i o u s types o f phytoplankton communities ( f l a g e l l a t e , diatom, or mixed) and v a r i o u s c o n c e n t r a t i o n s of phytoplankton and o t h e r growth v a r i a b l e s . The experimental d e s i g n i s shown i n T a b l e 16. As d e s c r i b e d i n Chapter 2, Tank 4 was the c o n t r o l with no o y s t e r s and Tanks 1, 2 and 3 were stocked with 2, 4 and 8 c u l t c h r e s p e c t i v e l y , with 8 o y s t e r s per a r t i f i c i a l c u l t c h . , 96 h e a l t h y j u v e n i l e o y s t e r s were s e l e c t e d and then d i v i d e d i n t o f o u r s i z e groups: very s m a l l (35-45 mm), s m a l l (45-55 nm), l a r g e (55-65 mm) and very l a r g e (65-75 mm). , The 8 *very small* o y s t e r s were attac h e d to C u l t c h #1, while the 32 o y s t e r s i n the 45-55 mm range were randomly chosen f o r placement on one of the f o u r •s m a l l * c u l t c h .( #2 t o #5).. A s i m i l a r procedure was used t o 81 produce the four " l a r g e 1 c u l t c h (#6 to #9) and the three * very l a r g e * c u l t c h (#10 t o #12), g i v i n g the r e g u i r e d twelve c u l t c h . T herefore the p r o d u c t i o n of o y s t e r s could be examined to some ext e n t as a f u n c t i o n of t h e i r d e n s i t y and s i z e i n each of the experiments. ., Before each h e r b i v o r e experiment, the c u l t c h were h e l d i n the outflow from the a p p r o p r i a t e primary tank f o r ca.. 24 hours. I n i t i a l measurements were taken f o r the o y s t e r growth v a r i a b l e s ( l e n g t h , width, depth, t o t a l weight, meat weight and s h e l l weight) arid the o y s t e r experiments conducted f o r one week p e r i o d s . , The temperature, oxygen l e v e l , c h l o r o p h y l l a c o n c e n t r a t i o n , urea and ammonia were monitored once a day at ca. 1200 hours PST. , fit the end of each experiment, the o y s t e r s were a g a i n weighed and measured and the f e c e s and pseudofeces c o l l e c t e d from the h e r b i v o r e tanks., E x p e r i m e n t a l R e s u l t s R e s u l t s f o r the o y s t e r experiments are summarized i n F i g u r e s 91 to 95 and Tables 24 t o 26., Appendix 2 c o n t a i n s the d e s c r i p t i o n and d e r i v a t i o n of a d d i t i o n a l v a r i a b l e s p e r t i n e n t t o the p r o d u c t i o n of h e r b i v o r e s . , Environmental C o n d i t i o n s during the O y s t e r Growth Experiments The i n s i t u temperatures during the o y s t e r growth experiments are i l l u s t r a t e d i n F i g u r e 91. Although t h e r e was no s i g n i f i c a n t d i f f e r e n c e i n temperature between tanks i n any of the f o u r experiments, there was a s i g n i f i c a n t d i f f e r e n c e (P=.001) i n TEMP between experiments (Table 24) . In Experiment 82 3, the temperature d u r i n g the week averaged the h i g h e s t value (23.3 °C ), r e s u l t i n g from two f a c t o r s . , The temperature of the source i n f l o w from Tank A was s i g n i f i c a n t l y higher than from Tank B (the source i n f l o w f o r the ether three experiments) and the f l u s h i n g r a t e of the h e r b i v o r e tanks i n Experiment 3 was only 1.0 day-* ., The 18.5 °C average temperature i n Experiment 1 was the lowest and most v a r i a b l e d u r i n g the one week p e r i o d . The temperatures i n Experiments 2 and 4 averaged 20.2 °G and 19.5 °C r e s p e c t i v e l y . As i l l u s t r a t e d i n Figure 92, the i n f l o w phytoplankton c o n c e n t r a t i o n s v a r i e d c o n s i d e r a b l y w i t h i n and between experiments. The low i n f l o w CHLA du r i n g the l a t t e r p a r t of the Experiment 3 was c o i n c i d e n t with the contamination of the primary Tank .A by protozoans, as mentioned i n Chapter 6., In a l l f o u r experiments* the phytoplankton c o n c e n t r a t i o n i n the c o n t r o l tank (4) was s i g n i f i c a n t l y lower than the i n f l o w c o n c e n t r a t i o n , i n d i c a t i n g a p r o p o r t i o n of the stock was l e s t t o the benthos i n s p i t e of the use of i n s i t u c i r c u l a t i n g pumps., The l o s s averaged 30$ i n Experiments 2 and 4 a t the 2.0 day -* f l u s h i n g r a t e and i n c r e a s e d t o 58% a t the 1.0 day-* f l u s h i n g r a t e i n Experiments ,1 and 3. S i n c e there were nc h e r b i v o r e s i n the c o n t r o l tank, these percentage l o s s e s of phytoplankton due to s i n k i n g would be higher compared to the other h e r b i v o r e tanks which had a s i g n i f i c a n t but v a r i a b l e g r a z i n g r a t e depending on the number of o y s t e r s per tank. In view of the l a c k of d i r e c t measurements of phytoplankton s i n k i n g r a t e s w i t h i n each h e r b i v o r e tank, the uptake of phytoplankton (STKUP) was estimated as the d i f f e r e n c e between 83 the i n f l o w and i n s i t u phytoplankton stock and p r o v i d e s a maximum estimate. The i n s i t u phytoplankton s t a n d i n g s t o c k decreased e x p o n e n t i a l l y i n Tanks 1 to 3 during the one week p e r i o d i n a l l four experiments, and the uptake of phytoplankton remained f a i r l y c o n s t a n t i n EXPII and EXPIV. In EXPI, the i n s i t u phytoplankton stock l e v e l s remained low i n a l l . t h r e e h e r b i v o r e tanks i n s p i t e of the i n c r e a s e d inflow c o n c e n t r a t i o n d u r i n g the l a s t h a l f of the experiment. . E x c l u d i n g the. c o n t r o l tank, there was a s i g n i f i c a n t d i f f e r e n c e (P=.QGO) i n STKUP between the four experiments, s i t h v a l u e s averaging 22.3 ug C h i a l ~ l , 24.5 ug Chi a 1~» , 7.8 ug C h i a I-* and 24.8 ug C h i a 1~* i n Experiments 1 to 4 (Table 24) ; although i f E X P I H i s excluded* s i n c e i t was the only growth experiment with the f l a g e l l a t e community as a food source, there were no d i f f e r e n c e s i n STKUP between experiments (?=.738). However, the f l u s h i n g r a t e s i n Experiments 2 and 4 were twice as h i g h as i n Experiment 1, and when the phytoplankton source was expressed as an uptake r a t e (STKUPE) , Experiments 2 and 4 had s i m i l a r average values of 8.4 mg C h i a dy-» , more than double the uptake r a t e i n Experiment 1., Since the stoc-k c o n c e n t r a t i o n i n Experiments II and 3 were grazed to a l e v e l approaching zero i n the three o y s t e r tanks, o n l y i n Experiments 2 and 4 was t h e r e a s i g n i f i c a n t d i f f e r e n c e i n STKUP between tanks. The phytoplankton stock l e v e l s i n Tank 3 with the h i g h e s t d e n s i t y of o y s t e r s were l e s s than 2 ug C h i a 1 _ 1 i n both EXPII and EXPIV. , The r a t i o of c h l o r o p h y l l b to c h l o r o p h y l l a (B&) i s a l s o summarized i n Table 24, s i n c e i t g i v e s some i n d i c a t i o n of the 84 s p e c i e s composition of the phytoplankton s t o c k . I n a l l experiments, the BA of the phytoplankton i n the h e r b i v o r e tanks were s i g n i f i c a n t l y higher than the c o n t r o l which r e t a i n e d a s i m i l a r value to the inflow.„, The o y s t e r s appear to p r e f e r e n t i a l l y graze the l a r g e diatoms, l e a v i n g an environment conducive to the growth of n a n o - f l a g e l l a t e s ( i . e . a high l i g h t and temperature, low n u t r i e n t system). A s i m i l a r t r e n d was a l s o apparent between the herbi v o r e tanks from the low to high d e n s i t i e s , p a r t i c u l a r l y i n EXPI and EXPIV. , Oxygen c o n c e n t r a t i o n s f o r the f o u r o y s t e r experiments are i l l u s t r a t e d i n F i g u r e 93. As with the phytoplankton s t o c k , the i n f l o w oxygen l e v e l s v a r i e d between experiments and the net oxygen uptake was c a l c u l a t e d as the d i f f e r e n c e between the i n f l o w and i n s i t u c o n c e n t r a t i o n s . The average uptake of oxygen (OxYUP) i n Experiments 1 to 4, e x c l u d i n g the c o n t r o l tank, »as 3.77 mg 1-* , 5.45 mg 1— 1 . , 3.85 mg 1~» and 5.23 mg 1-* r e s p e c t i v e l y . During Experiment 3, the oxygen c o n c e n t r a t i o n i n , the:! three o y s t e r tanks i n c r e a s e d d u r i n g the l a s t h a l f o f the experiment t o l e v e l s above the i n f l o w c o n c e n t r a t i o n . Furthermore, the uptake i n Tank 3 was the l e a s t although t h i s tank c o n t a i n e d the h i g h e s t d e n s i t y c f o y s t e r s . T h i s i s i n c o n t r a s t to the oth e r three experiments, i n which there was a s i g n i f i c a n t i n c r e a s e (p=.006) i n 0XYUP between Tanks 1 to 3. When the uptake o f oxygen was expressed as a r a t e , OXYDPfi was l e a s t i n EXPI ( 640 mg d y - i ) and g r e a t e s t i n EXPII (1852 mg dy -* ) i n c o n t r a s t t o the r e s u l t s f o r STKUP8. By comparing the OXYUPR:STKUPR r a t i o , i t i s apparent t h a t t h i s r a t i o was l e a s t f o r , EXPI (0.17), with v a l u e s o f 0.22 f o r EXPII and EXPIV and a 85 l a r g e maximum r a t i o of 0.49 f o r EXPIII. , Furthermore, these r e s u l t s are p o s i t i v e l y c o r r e l a t e d with temperature. ammonia, the primary e x c r e t o r y product cf o y s t e r s , d i d not i n c r e a s e s i g n i f i c a n t l y i n any of the experiments, with pr o d u c t i o n r a t e s of 1.9 ufl NH3 1--* , 0 . 8 u£i Nii3 , 1 . 4 uM NH3 l"-» and 0.6 uu N H 3 1~1 , , There was no ' s i g n i f i c a n t d i f f e r e n c e between tanks e i t h e r , and the r e s u l t s i n d i c a t e t h a t a steady s t a t e e x i s t e d between NH3 uptake by phytcplankton and NH3 e x c r e t i o n by the h e r b i v o r e s . There was no s i g n i f i c a n t i n c r e a s e i n USEA c o n c e n t r a t i o n s e i t h e r . , O y ster Growth as a Function o f the E x p e r i mental F a c t o r s E e s u l t s of the o y s t e r growth i n terms of the three experimental f a c t o r s , experiment (EXP), d e n s i t y (DENS) and s i z e (SIZE)) are summarized i n Table 25 and T a b l e 26 and i l l u s t r a t e d i n F i g u r e s 94 and 95. The means and standard d e v i a t i o n s f o r the s i x growth v a r i a b l e s ( l e n g t h , width, depth, t o t a l weight, meat weight and s h e l l weight) were c a l c u l a t e d f o r each of the twelve o y s t e r c u l t c h (n=8) a t the beginning of each .herbivore experiment (Table 25). The i n i t i a l dimensions and weights, averaged f o r the t o t a l p o p u l a t i o n of o y s t e r s (N=96), were: le n g t h (L)= 5.7 cm; width(W)= 3.2 cm; depth (D)= 1.7 cm; t o t a l weight (SGTT) = 12.8 g; meat weight (flGT«)= 4.0 g; s h e l l weight (BGTS) - 8.8 g. . at the end o f a l l f o u r experiments, the average l e n g t h had i n c r e a s e d by 0.4 cm (7%) , the width by 0.6 cm (181) and the depth by 0.2 (12%). The t o t a l weight i n c r e a s e d by 50% tc 19,2 g, with HGTM r e p r e s e n t i n g 32% of the t o t a l weight, which was the same 86 p r o p o r t i o n as the i n i t i a l measurements. The net and percent i n c r e a s e s during each experiment were c a l c u l a t e d f o r a l l s i x growth v a r i a b l e s f o r each o y s t e r and the averages summarized i n Table 26. Average net i n c r e a s e s f o r a l l three dimensional measurements of growth (NETL, NETW and NETD) were s i g n i f i c a n t l y d i f f e r e n t (P>.001) between experiments. Maximum average i n c r e a s e s of 0.17 cm, 0.24 cm and 0.08 cm were a t t a i n e d during EXPII f o r NETL, NETH and NETD r e s p e c t i v e l y ; these val u e s r e p r e s e n t more than 4 0% of the t o t a l i n c r e a s e f o r the e n t i r e experimental p e r i o d (four weeks) f o r a l l three v a r i a b l e s . In terms of percent i n c r e a s e s * t h i s r e p r e s e n t s v a l u e s o f 3.2% week-* f o r PEEL, 7.5% week-* f o r PEHW and 4.7 % weekT* f o r PESD. The lowest average net i n c r e a s e s i n the l i n e a r dimensions of the o y s t e r p o p u l a t i o n o c c u r r e d i n EXPIV, with growth r a t e s o f l e s s than 1.2% per week. There were a l s o s i g n i f i c a n t d i f f e r e n c e s between experiments i n the net i n c r e a s e s i n the growth v a r i a b l e s which were measured i n terms of weight.. The l a r g e s t net i n c r e a s e s occurred i n EXPIV, with averages of 2.1 g/oyster f o r NETKT, 0.7 g f o r NETHM and 1.4 g f o r NETHS. Large n e t i n c r e a s e s i n the t o t a l weight, meat weight and s h e l l weight a l s o occurred i n EXPII , which on the b a s i s of % i n c r e a s e i n growth, were the l a r g e s t average v a l u e s f o r t o t a l weight (PE£WT=13.51 week -* ) , meat weight (PEEBfi-15.4%) and s h e l l weight (PEBHS= 12. 6%) .'• , A s i m i l a r p a t t e r n of growth was apparent i n EXPIV and EXPI, with s l i g h t l y lower 1 The % growth r a t e was c a l c u l a t e d f o r each o y s t e r as the net i n c r e a s e d u r i n g the experimental p e r i o d d i v i d e d by the value a t the beginning of that,experiment. 8 7 percentage i n c r e a s e s . During EXPIII, there sas only an 8.1% i n c r e a s e i n the t o t a l weight and the r a t i o of NETWM:NETWT dropped t o ca.-, 0.17 from the 0.37 du r i n g EXPI and EXPII. , I t was low compared with the o r i g i n a l HGTH:WGTT r a t i o of 0 . 3 2 , hut by the end of EXPIV, the r a t i o had r e t u r n e d to 0.34. F i n a l l y , t h e s m a l l e s t i n c r e a s e i n s h e l l weight occurred i n EXPIV.,, The net and percent i n c r e a s e s i n growth are i l l u s t r a t e d as a f u n c t i o n of the f a c t o r s d e n s i t y (DENS) and s i z e (SIZE) f o r a l l s i x dependent v a r i a b l e s . . In F i g u r e 94, the oy s t e r growth i n each experiment i s broken down by d e n s i t y , with DENS=1 corr e s p o n d i n g to the lowest d e n s i t y i n Tank 1, DENS=2 to the medium d e n s i t y i n Tank 2 and DENS=3 to the highest d e n s i t y i n Tank 3. There was g e n e r a l l y a decrease i n the average net l i n e a r dimensions with an i n c r e a s i n g d e n s i t y of o y s t e r s , p a r t i c u l a r l y i n EXPI and EXPII., However the d i f f e r e n c e s i n the l i n e a r , dimensions between DEWS ware not s i g n i f i c a n t on a net or percentage b a s i s , except i n the case of depth f o r EXPI and EXPII., The r e s u l t s f o r EXPIII and EXPIV d i d not f o l l o w a s i m i l a r d e f i n i t e p a t t e r n . , The hi g h e s t l i n e a r growth r a t e s i n EXPIII were found i n the high d e n s i t y tank, while i n EXPIV, the medium d e n s i t y tank (2) had the lowest r a t e s . In terms o f the weight v a r i a b l e s , there was g e n e r a l l y a s i g n i f i c a n t decrease i n t o t a l weight, meat weight and s h e l l weight with an i n c r e a s i n g d e n s i t y of o y s t e r s . , However i n EXPII, o y s t e r s i n the medium d e n s i t y tank grew more than those i n the low d e n s i t y tank, although on a percentage b a s i s , t h i s , trend p e r s i s t e d only i n the case of NETWM. , When c o n s i d e r i n g the growth i n weight on a percentage b a s i s , the s i g n i f i c a n c e l e v e l s 88 were l e s s and there was no s i g n i f i c a n t i n c r e a s e i n PEBWfl with DENS i n any of the experiments. I t appears that the combination of a lew FB o f the secondary system and low i n f l o w c o n c e n t r a t i o n of phytoplankton was l i m i t i n g an i n c r e a s e i n growth i n E X p i i l ; by d o u b l i n g the flow r a t e i n the o y s t e r tanks i n EXPII, o n l y the o y s t e r s i n the high d e n s i t y tank (DENS=3) were l i m i t e d i n growth.. However, i n EXPIV there was a s i g n i f i c a n t d i f f e r e n c e i n growth between DENS although the FB and values of the c o v a r i a t e s (STKUP, OXYUP and TEHP) were s i m i l a r to EXPII. In f a c t the only d i f f e r e n c e between EXPII and EXPIV was the type of phytoplankton community., Within experiments, the p a t t e r n between s h e l l weight and t o t a l weight as a f u n c t i o n o f DENS, were s i m i l a r . The e f f e c t of SIZE upon growth r a t e s c f o y s t e r s d i f f e r e d more between experiments depending cn the v a r i a b l e s under c o n s i d e r a t i o n (Figure 95). I n terms of l i n e a r dimensions, there was g e n e r a l l y a decrease i n NET! and P.EB.L with i n c r e a s i n g s i z e , p a r t i c u l a r l y i n EXPI and EXPII.., on the other hand, although t h e r e were s i g n i f i c a n t d i f f e r e n c e s i n width between the s i z e o f o y s t e r s i n some experiments, t h e r e was no s i g n i f i c a n t l i n e a r e f f e c t (Table 26)., T h i s was a l s o t r u e of NETD and PEBD., In terms of the weight v a r i a b l e s , the l a r g e r s i z e 3 and H o y s t e r s had the h i g h e s t net growth r a t e s i n a l l experiments, although on a percentage b a s i s , . the t r e n d was r e v e r s e d . ,.: There was a s i g n i f i c a n t l i n e a r e f f e c t o f s i z e upon PEBwT and PEBWS i n a l l fo u r experiments., Growth i n meat weight was not a f u n c t i o n of SIZE i n EXPIII.„ 89 CHAPTEB 8./ ANALYSIS OF THE BESULTS USING J SIMULATION MODEL E s t i m a t i o n o f the P h y s i o l o g i c a l Parameters d uring the Continuous  C u l t u r e s In order to estimate a p p r o p r i a t e parametric values f o r a primary p r o d u c t i v i t y model of t h i s e c o s y s t e a , a s h o r t s e r i e s of experiments cn p h o t o s y n t h e t i c p r o d u c t i v i t y as a f u n c t i o n o f l i g h t , temperature and n u t r i e n t s ( n i t r a t e ) were conducted s i m u l t a n e o u s l y with EXP5. Phytoplankton samples were taken from the s u r f a c e of Tank B (F.EU = 1*0 day-* ) cn f o u r c o n s e c u t i v e days during the i n i t i a l blccm p e r i o d (Days 3 to 7) , and on each day, p r o d u c t i v i t y versus l i g h t i n t e n s i t y (PAB) was examined at one of the f o u r e x p e r i m e n t a l temperatures ( 14 °C , 16 °C , 18 ° C or 20 °C ) . , T h i s process was repeated f o r the three h i g h e s t temperatures d u r i n g the i n i t i a l p e r i o d of n u t r i e n t d e p l e t i o n i n the primary tank (Days 10 t o 12) Primary p r o d u c t i v i t y f o r the phytoplankton samples was measured by the uptake cf r a d i o a c t i v e c a r b c t i n a s p e c i a l l y c o n s t r u c t e d water-cooled i n c u b a t o r , at e i g h t l e v e l s of n a t u r a l i r r a d i a n c e u s i n g n e u t r a l d e n s i t y f i l t e r s . A l l the experiments were c a r r i e d out during c l e a r , b r i g h t days and t h e r e was no s i g n i f i c a n t d i f f e r e n c e i n SB between days during the i n c u b a t i o n p e r i o d from 1030 t o 1430 hours P.S.T. The t o t a l r a d i a t i o n i n each compartment o f the i n c u b a t o r was measured with the s c l a r i m e t e r and the PAB was c a l c u l a t e d as 0.50 of t h i s value as o u t l i n e d i n Chapter 2.v The t e c h n i q u e s f o r the measurement of 90 primary p r o d u c t i v i t y and s t a n d i n g s t o c k are a l s o d e s c r i b e d t h e r e . , The r e s u l t s of the *F versus I* experiments are i l l u s t r a t e d i n F i g u r e 96. A l l v a l u e s of primary p r o d u c t i v i t y were normalized i n terms of CHLA, and as expected, the curves do not pass through the o r i g i n s i n c e the radiocarbon method approximates net p a r t i c u l a t e p r o d u c t i v i t y ( M c A l l i s t e r e t a l . ,1964; Eppley and Sloan,1965). The curves i n d i c a t e d a h y p e r b o l i c r e l a t i o n between P 6 and PAR f o r both s e t s of n u t r i e n t c o n d i t i o n s , and the asymptote i n c r e a s e d with temperature. During the bloom p e r i o d , p h o t o - i n h i b i t i o n was apparent a t the h i g h e s t experimental l i g h t i n t e n s i t y f o r a l l f o u r experimental temperatures; these data p o i n t s were not i n c l u d e d i n the e s t i m a t i o n o f the parameters of the v a r i o u s mathematical f u n c t i o n s t e s t e d . The two common parameters i n the mathematical r e l a t i o n s h i p between primary p r o d u c t i v i t y and l i g h t , namely the i n i t i a l slope ALPHA ( ug C (ug C h l a ) - 1 h r - 1 ( l y / m i n ) - * ) of the l i n e a r p o r t i o n of the l i g h t s a t u r a t i o n curve, and IMAx ( ug C (ug C h l a ) - * h r - 4 ) , the asymptote or p h o t o s y n t h e t i c r a t e a t o p t i m a l i r r a d i a t i o n , were estimated f o r the seven 'P versus I* experiments. Two h y p e r b o l i c models were used to d e s c r i b e the data: the h y p e r b o l i c tangent P 6 (I) = PMAX * T ANB( ALPHA*X (I) /PM AX) - R 6 and Smith's f u n c t i o n (Smith, 1936) P 6 (I) = PMAX*ALPHA* X (1) / (SQRT ( (P MAX**2) +(ALPHA*X (I) ) **2) ) - R B 91 using a n o n - l i n e a r l e a s t squares f i t (LSF) procedure o u t l i n e d i n Bevington (1969). The parametric e s t i m a t e s f o r ALPHA and .Re, , the r e s p i r a t i o n term or n e g a t i v e i n t e r c e p t at zero i r r a d i a n c e , were f i r s t c a l c u l a t e d using l i n e a r r e g r e s s i o n as advised by Jassby and P i a t t (1976)., The r e s u l t i n g e s t i m a t e s f o r these parameters were then used i n the e s t i m a t i o n cf the gross P C 1 A X . The mathematical r e s u l t s f o r both models are summarized i n T a b l e 19, i n c l u d i n g input and output values and parameters. The PMX v a l u e s r e p o r t e d are based on net p r o d u c t i v i t i e s ( ug C (ug C h l a ) - * hr-* ). The l e a s t squares f i t was e v a l u a t e d by c a l c u l a t i n g the reduced chi-square using a g r i d search technique. I n a l l c a s e s , the f i t s were e x c e l l e n t with P>.90 t h a t the a c t u a l and f i t t e d data were the same.. Furthermore, there was l i t t l e d i f f e r e n c e between the f i t o f the two models, although the standard d e v i a t i o n s of PMAX, SIGHAA, were much l e s s u sing the TANH model i n a l l 7 cases. The values of ALPHA were a l s o s i m i l a r between bloom and post-bloom c o n d i t i o n s a t any given temperature. The data i n F i g u r e 96 i n d i c a t e d that the PHAX*s were l e s s d u r i n g the post-bloom p e r i o d . , A t - t e s t of the h y p o t h e s i s t h a t the PMAX*s f o r bloom and post-bloom c o n d i t i o n s (for a given temperature) are equal, i n d i c a t e d t h at t h i s parameter was not s i g n i f i c a n t l y d i f f e r e n t (P>.10) between the blccm and post-bloom c o n d i t i o n s f o r 16, °C , 18 °C or 20 °C .... The v a r i a b i l i t y i n the f o r c i n g c o n d i t i o n s (Sfi,TEMP,N0.3) during Experiment 5 made i t d i f f i c u l t t o c o n f i r m t h i s h y p o t h e s i s . Furthermore, the c e l l s i z e and s e l f - s h a d i n g of the phytoplankton may have.an important e f f e c t on the l i g h t s a t u r a t i o n curve ( P i a t t and Jassby, 1976) as well 9 2 as the temperature and n u t r i e n t s t a t u s of the c e i l s . S i m u l a t i o n of the Phytoplankton Dynamics D e s c r i p t i o n of the Model In order to t e s t the v a l i d i t y cf the p r o d u c t i v i t y model using the e x p e r i m e n t a l l y determined parameters, a s e r i e s of s i m u l a t i o n s were run using SIMCQN, a s i m u l a t i o n c o n t r o l command language V , with the model programmed i n FOBTB&N. The primary purpose of the s i m u l a t i o n s «as to p r e d i c t the phytoplankton stock over time from the primary p r o d u c t i v i t y model and compare i t with the a c t u a l e x p e r i m e n t a l r e s u l t s . The o p e r a t i o n a l procedure of the s i m u l a t i o n allowed the d a i l y v a l u e s of the f o r c i n g c o n d i t i o n s , s o l a r r a d i a t i o n (SB), temperature (TEMP) and n i t r a t e (N03), and the seed phytoplankton c o n c e n t r a t i o n t o be read i n i n i t i a l l y . The i n c r e a s e i n the phytoplankton stock was then c a l c u l a t e d based on the p r o d u c t i v i t y model and t h i s d e r i v a t i v e added to the i n i t i a l value i n order t o estimate the phytoplankton s t o c k a f t e r t h a t day. T h i s ' f i n a l 1 value was then used as the i n i t i a l phytoplankton stock f o r the f o l l o w i n g day. The number of I t e r a t i o n s of t h i s procedure was s p e c i f i e d i n t e r a c t i v e l y i n SIMCOM and was determined by the number of days i n the i Documentation f o r t h i s procedure i s a v a i l a b l e from the UBC Computing Centre f i l e iaBE:SIMCON.» 93 experiment. I t should be noted t h a t i n the f o l l o w i n g d i s c u s s i o n , PHYTO and P r e p r e s e n t the s i m u l a t i o n v a r i a b l e s f o r the phytoplankton s t o c k and a s s i m i l a t i o n r a t e , and correspond t o the. experimental v a r i a b l e s CHLA and ASS. PBAV r e p r e s e n t s the CHLA data averaged f o r a l l f o u r In s i t u s t a t i o n s . , The b a s i c s t r u c t u r e of the model i n c l u d e d c a l c u l a t i o n o f the e x t i n c t i o n c o e f f i c i e n t (EXTK) using B i l e y ' s equation i n which EXTK i s a f u n c t i o n of PHYTO (see Chapter 2). The p h o t o s y n t h e t i c a l l y a v a i l a b l e r a d i a t i o n was c a l c u l a t e d as an average f o r the tank (since the system was t u r b u l e n t l y mixed) using the equation: PABAV= 0.5*Sfi/(EXTK*2) * (1-EXP (-EXTK*Z) ) with t h e . a p p r o p r i a t e conversion f a c t o r to transform the v a r i a b l e i n t o l a n g l e y min-* . The growth r a t e , GECM ( t ~ * ), was then e s t i m a t e d u s i n g the f o l l o w i n g eguations determined from the r e s u l t s of the *P versus I ' experiments: GBOWH = P /CCHLA where P = PMAX*TANH (AIPHAI*PAEAV/P13AX) PMAX = PTMAX*TANH(ALPHAT*TEMP/PTM AX) and CCHLA i s the CABBQN:CHLA r a t i o . „ The e s t i m a t e s of ALPHAI were taken d i r e c t l y from T a b l e 19. However, because o f the l i m i t e d number of data p o i n t s i n the *P versus TEMP • cur v e s , the e s t i m a t e s o f the corres p o n d i n g parameters, ALPHAT (the i n i t i a l slope) and PTMAX (the maximum p r o d u c t i v i t y at the optimal SB and TEHP f o r the given n u t r i e n t c o n d i t i o n s ) , , were more d i f f i c u l t to p r e d i c t . A survey of the l i t e r a t u r e suggested t h a t PMAX approaches a maximum a t temperatures only m a r g i n a l l y h i g h e r than 20 °C f o r a Skeletonema 94 costatum p o p u l a t i o n . So by e x t r a p o l a t i o n of the data i n t h i s experiment (Figure 96, Table 27), values from 10,0 t o 15.0 seemed reasonable f i r s t approximations f o r PTMAX. No d i r e c t measurements of the c a r b o n r c h l o r o p h y l l a parameter (CCHLA) were p o s s i b l e . However, other experiments have i n d i c a t e d t h a t CCHLA i s a f u n c t i o n of the phytoplankton dynamics, with v a l u e s of ca. 30 during bloom c o n d i t i o n s f o r a s i m i l a r phytoplankton community, i n c r e a s i n g to values of ca. 60 i n a n u t r i e n t -d e p l e t e d system (see Parsons and Takahashi, 1973a). These CCHLA val u e s were used i n the s i m u l a t i o n s d u r i n g the a p p r o p r i a t e p e r i o d s as i n d i c a t e d by the experimental r e s u l t s . , An i n t e r m e d i a t e CCHLA value of 45 was a l s o used during p e r i o d s of r e l a t i v e l y s t e a d y - s t a t e phytoplankton c o n c e n t r a t i o n s . A f t e r the c a l c u l a t i o n of the growth r a t e of the phytoplankton, the d e r i v a t i v e was c a l c u l a t e d as: d(PHYTO)/dt = (GBOWB*PHYTO)-(FB*PHYTO) - (SINK*PHYTG) The s i n k i n g r a t e of the phytoplankton, SINK ( t - 1 ) , was i n t r o d u c e d i n t o the equation as w e l l as the f l u s h i n g r a t e . Even though the system was c o n t i n u a l l y mixed, some l o s s o f phytoplankton to the benthos was apparent, p a r t i c u l a r l y a f t e r the ( i n i t i a l d e p l e t i o n of n i t r a t e . S i n k i n g r a t e s of 0.10 d a y - 1 t o 0.30 d a y - 1 were t e s t e d i n the s i m u l a t i o n runs based on some experimental e s t i m a t e s . 95 S i m u l a t i o n R e s u l t s The r e s u l t s of some of the s i m u l a t i o n runs f o r Experiment 5 are i l l u s t r a t e d i n F i g u r e s 97 t o 100 f o r EXP5E and F i g u r e s 101 and 102 f o r EXP5A. The s i m u l a t i o n a n a l y s i s was f i r s t a p p l i e d to the : data from EXP5B, the experiment with t i e constant f l u s h i n g r a t e f o r s i x weeks. During the s i m u l a t i o n s * the FB was s e t at 1,0 d a y - 1 , and on Day 41, was decreased to 0,5 d a y - 1 as i n the experiment. The s i n k i n g rate was i n i t i a l l y s e t at 0,0 d a y - 4 ; a f t e r t h e bloom, SINK was a l t e r e d to 0,3 d a y - 1 f o r f o u r days (si n c e the tank was very c l e a r d u r i n g t h i s p e r i o d ) , and then held c o n s t a n t a t 0,1 d a y - 1 f o r the remainder of the experiment. The CCHL r a t i o was s e t a t 30, i n c r e a s e d to 60 durin g the post-bloom p e r i o d , and r e s e t to ah i n t e r m e d i a t e value of 45 during the t h i r d week when the a c t u a l phytoplankton s t o c k c o n c e n t r a t i o n was f a i r l y s t a b l e . During the f o u r t h week, CCHL was a l t e r e d to 30 i n view of the l a r g e i n c r e a s e i n the i n f l o w n i t r a t e c o n c e n t r a t i o n (Figure 74). CCHL was.then i n c r e a s e d t o 45 u n t i l t h e : end of the 1,0 day-* FB p e r i o d and r e s e t to 60 when FB was a l t e r e d to 0.5 day-* . As i l l u s t r a t e d i n F i g u r e 97, us i n g these parameters plus those d e r i v e d from the 'P versus I * data, a reasonable approximation of the a c t u a l phytoplankton s t o c k (PHAV) was esti m a t e d by the s i m u l a t i o n model (PHYTO)• The magnitude and ti m i n g o f the maxima were s i m i l a r although the simulated data had a one day time l a g during the f i r s t two weeks compared with PHAV, / The s e n s i t i v i t y of the system was tested by a l t e r i n g the parameters i n the model., By i n c r e a s i n g SINK frcm 0.3 d a y - 1 to 0.4 day-* a f t e r the i n i t i a l bloom, the recover y o f the 96 phytoplankton stock i n the middle of the t h i r d week was reduced by c a . 50%, although the PHYTO(max) f o r the s i m u l a t i o n was then c l o s e r t o the experimental value of 54.2 ug Chi a 1 _ 1 (Figure 9 8 ) . On the other hand, by maintaining a constant SINK of 0.1 d a y - 1 a f t e r the i n i t i a l bloom, the pcst-blccm o s c i l l a t i o n s i n phytoplankton stock are not as c l o s e l y approximated (Figure 99)• A s i g n i f i c a n t f e a t u r e of the p l o t s was how the s i m u l a t i o n model p o i n t s out the p e r i o d s i n which SB or N03 were the predominant f o r c i n g c o n d i t i o n s . , The a c t u a l ; and simulated damped o s c i l l a t i o n s a f t e r the i n i t i a l bloom and d e p l e t i o n of N03 i n d i c a t e d t h a t the v a r i a b i l i t y i n SB had a s i g n i f i c a n t e f f e c t on the s t a n d i n g stock. However, during the f o u r t h week, the v a r i a b i l i t y i n the simulated phytoplankton stock was not apparent i n the experimental r e s u l t s i n d i c a t i n g t h a t the system was not l i g h t - l i m i t e d . The growth was then a f u n c t i o n of the n i t r a t e c o n c e n t r a t i o n and the model could be a d j u s t e d so t h a t GBOWB was a f u n c t i o n of the uptake and a s s i m i l a t i o n of N03, o f t e n d e s c r i b e d by Michaelis-Menten k i n e t i c s . The o r i g i n a l estimate of 10.0 ug c (ug C h l a ) - 1 h r - 4 f o r the p r o d u c t i v i t y parameter PTMAX used i n the c a l c u l a t i o n of EHYTO (Figure 97) provided a c l o s e r p r e d i c t i o n o f the experimental s t a n d i n g stock compared with PTMAX=12. 0 (Figure 100) or h i g h e r values of PTMAX. , The c o n d i t i o n s and r e s u l t s c f EXP5A were more d i f f i c u l t t o simulate a c c u r a t e l y because of the changes i n FB and the use of lower FB*s (0.1 d a y 4 to 0.5 day-* ) which would a l t e r the magnitude and frequency of the parameters i n the system. S i m u l a t i o n runs u s i n g a constant value of 10.0 f o r PTMAX, with the a p p r o p r i a t e f l u s h i n g r a t e s and reasonable estimates of the 97 s l a k i n g r a t e s (0.25 day-* f o r P e r i o d 1; 0. 1 d a y - 1 f o r P e r i o d 2; 0.5 day -* f o r P e r i o d 3 ), r e s u l t e d i n a PHYTO(max) which was about twice as l a r g e as P H A V ( m a x ) S i n c e PTKAX decreases with the n u t r i e n t c o n c e n t r a t i o n of the system, PTMAX was decreased t o 5.0 ug G (ug C h l a ) - 1 hr~* a f t e r the i n i t i a l bloom and was r e s e t to 8.0 ug C (ug C h l a ) - 1 hr~* d u r i n g P e r i o d 2 and t o 5.0 ug C (ug C h l a ) - * hr~* during Period 3. S i m i l a r l y a value of 60 was assigned to CCHL d u r i n g Period. 2 and CCH1=75 f o r the 0. 10 day-* FB period.,. As i l l u s t r a t e d i n F i g u r e 101, the r e s u l t i n g s i m u l a t e d phytoplankton stock (PH¥10) d i d not show a s i g n i f i c a n t post-blccm decrease and recovery (PHAV). I f SINK was in c r e a s e d t o 0.6 day-* •, the s i m u l a t i o n p a t t e r n and magnitude more c l o s e l y approximated PHAV. As s i g h t be expected, the system was l e s s s e n s i t i v e to changes i n SB compared to the combination o f the changes i n FB and low i n f l o w c o n c e n t r a t i o n s of N03. a g r a z i n g term (GBA2E) of 0.5 day-* was introduced i n t o the model s t a r t i n g on Day 27 a f t e r t h e phytoplankton stock reached l e v e l s of ca. 50 ug C h i a 1~* i n response t o the high i n f l o w c o n c e n t r a t i o n of N03. as i l l u s t r a t e d i n F i g u r e 103, there was a s i g n i f i c a n t recovery of the phytoplankton steck even with the a d d i t i o n a l g razing pressure., T h i s r e s u l t e d from the negative feedback e f f e c t of the consequent r e d u c t i o n i n the e x t i n c t i o n c o e f f i c i e n t , coupled with the high NC3 c o n c e n t r a t i o n . Hhen the gr a z i n g r a t e was i n c r e a s e d to 1.0 day-* , the primary system •crashed* d u r i n g the s i m u l a t i o n run. T h i s s c e n a r i o corresponded to an o v e r a l l phytoplankton l o s s r a t e of 2.0 day -* . a s i m i l a r e f f e c t was obtained e x p e r i m e n t a l l y by Brown and Parsons (1972) when a l a r g e tank »as f l u s h e d at a r a t e of 2.0 day-* and the 98 phytoplaokton stock was reduced t o z e r o . 9 9 CHAPTER 9. COMPARATIVE DISCUSSION OF THE EXPERIMENTAL RESULTS The experimental r e s u l t s o f t h i s study have i n d i c a t e d the importance o f the f l u s h i n g r a t e and turbulence of the system i n determining the dynamics of h e r b i v o r o u s food c h a i n s . , The v a r i o u s f l u s h i n g r a t e s provided a d i f f e r e n c e i n the i n f l o w c o n c e n t r a t i o n s of n u t r i e n t s and temperature, with subseguent p r o p o r t i o n a l changes i n phytoplankton stock and the a v a i l a b l e r a d i a t i o n f o r primary p r o d u c t i v i t y , as w e l l as changes i n the composition o f the phytoplankton communities. The primary p r o d u c t i v i t y at a l l the experimental f l u s h i n g r a t e s (0.25 d a y - 1 t o 1.00 day-* ) was enhanced by using a deep n u t r i e n t - r i c h source o f seawater which averaged c a . 20 uM N l _ t d u r i n g the experiments, except Experiment 1 which was conducted i n the autumn (av N03 = 2k uM N 1~ 4 ) . The i n t e r a c t i o n between the f l u s h i n g r a t e (0.5 d a y - 4 ) and a c o n s t a n t upwelling r a t e i n a s t r a t i f i e d water column determined the dynamics of the primary community i n the one-stage c u l t u r e with constant f o r c i n g c o n d i t i o n s (EXPI). U n l i k e the o t h e r experiments, t h i s system was l i g h t - l i m i t e d due to the r e s t r i c t i o n s on the l i g h t i n t e n s i t y which could be achieved by an a r t i f i c i a l source. The r e p r o d u c i b i l i t y of the dynamics of the primary system was e x c e l l e n t between the the d u p l i c a t e e x p e r i m e n t a l tanks during the six-week pre-grazing p e r i o d , p a r t i c u l a r l y i n the f i r s t t h r e e weeks . The d i f f e r e n t i a l s i n k i n g r a t e o f the phytoplankton, r e l a t i v e to the constant u p w e l l i n g r a t e , c o n t r i b u t e d to the s i g n i f i c a n t i n c r e a s e i n CHLA' with depth and v a r i a b i l i t y over time. H i t h i n each depth, the 100 phytoplankton stock d i s p l a y e d a s e r i e s of da aped o s c i l l a t i o n s and reached a s t e a d y - s t a t e a f t e r one month, averaging approximately 30 ug C h i a l~l f o r the water column. The s t r a t i f i c a t i o n of the system a l s o promoted a change i n the composition of the primary community as a f u n c t i o n of depth i n response to the decrease i n PAB and TEMP.. M i c r o - f l a g e l l a t e s were dominant a t the s u r f a c e compared with diatoms a t the bottom s t a t i o n . . The dynamics o f the phytoplankton community were complicated by a w a l l e f f e c t , the growth of a f i l a m e n t o u s N a v i c u l a s p e c i e s at the s u r f a c e cf the tanks. .. T h i s diatom developed i n t o l a r g e f l o c c u l e n t mats, , supported by oxygen •vacuoles*, and f u r t h e r reduced the l i g h t i n t e n s i t y a t depth, p a r t i c u l a r l y i n Tank B. In c o n t r a s t , the c u l t u r e experiments i n both the non-t u r b u l e n t and t u r b u l e n t systems with n a t u r a l f o r c i n g c o n d i t i o n s of s o l a r r a d i a t i o n and temperature were n u t r i e n t - l i m i t e d most of t h e t i m e , and there was an i n d i c a t i o n t h a t seme m i c r o - n u t r i e n t {such as v i t a m i n B12) may have r e p l a c e d n i t r a t e as the l i m i t i n g n u t r i e n t i n some of the experiments. The low f l u s h i n g r a t e of 0.25 d a y - 1 , combined with the l a c k of a r t i f i c i a l mixing, allowed a l a r g e degree of thermal s t r a t i f i c a t i o n to develop, p a r t i c u l a r l y during periods of high s o l a r r a d i a t i o n . The s t r a t i f i c a t i o n was almost t o t a l l y e l i m i n a t e d during Experiments 4 and 5 by i n t r o d u c i n g a r t i f i c i a l t u r b u l e n c e . D e s p i t e the v a r i a b i l i t y i n SB, TEMP and N03 between th e experiments, the phytoplankton bloom occurred on Day 5 i n a l l the experiments with an i n i t i a l FB=0.25 day-* ; i n c o n t r a s t , the CHIA i n the experiments a t 1.0 day-* d i d not reach a naximum u n t i l Day 8. 1 0 1 In a l l cases, the bloom was.coincident with the d e p l e t i o n of i n -s i t u n i t r a t e c o n c e n t r a t i o n s . The magnitude of the bloom was a f u n c t i o n of the f l u s h i n g rate (and the a s s o c i a t e d N03 con c e n t r a t i o n ) and the t i m i n g and magnitude cf SR, but i n s p i t e of t h i s , g e n e r a l l y ranged between 30 to 40 ug Chi a 1~ 1 i n a l l of the experiments. In the primary c u l t u r e s with no g r a z i n g pressure (Experiments 4 and 5), t h e r e was a high c o r r e l a t i o n between the oxygen production and phytoplankton s t o c k . In the one-stage c u l t u r e with i n s i t u h e r b i v o r e s , the c o r r e l a t i o n was reduced as a r e s u l t of the uptake of oxygen by the h e r b i v o r e s and the decrease i n CELA by g r a z i n g . , The s t a n d a r d i z e d primary p r o d u c t i v i t y r a t e s (ASS) were a l s o much g r e a t e r i n magnitude and v a r i a b i l i t y during these experiments (Experiments 2 and 3), probably as a r e s u l t of the lower f l u s h i n g rate as w e l l as the g r a z i n g pressure. The r e s u l t s i n Experiment 4 i n d i c a t e d t h a t f o r the same f o r c i n g c o n d i t i o n s of SR, TEMP and NC3, the phytoplankton stock doubled when the f l u s h i n g r a t e was doubled f r c n 0.5 d a y - 1 to 1.0 day-* , provided t h a t the system was t c r b u l e n t l y mixed t o minimize the l o s s o f phytoplankton to the benthos.. At f l u s h i n g r a t e s g r e a t e r than 0 .5 d a y - 1 , t h e primary community was mainly composed of diatoms. The pigment r a t i o s and C o u l t e r counts provided s u p p o r t i n g evidence t h a t there was l i t t l e change i n the composition of the primary community a t c o n s t a n t , high (>0.5 day - i ) f l u s h i n g r a t e s , although the p r o p o r t i o n of n a n o - f l a g e l l a t e s i n c r e a s e d during p e r i o d s of low i n f l o w N03. A component a n a l y s i s of gross primary p r o d u c t i v i t y during Experiments 4 and 5 i n d i c a t e d t h a t at f l u s h i n g r a t e s of 0.5 day 102 - 1 o r g r e a t e r , a l a r g e p r o p o r t i o n < 5 0% to 60%) of the primary p r o d u c t i v i t y was * l o s t * by exudation, compared with 30% a t lower f l u s h i n g r a t e s (0.1 d a y - 1 and 0.25 dayr* ) . The r e s p i r a t i o n f r a c t i o n i n the systems with high f l u s h i n g r a t e s was 15%, approximately one-half the value f o r the lower f l u s h i n g r a t e s , probably as a r e s u l t of the lower i n s i t u temperatures. , The a s s i m i l a t i o n f r a c t i o n was more v a r i a b l e and ranged from 20% to 35% a t f l u s h i n g r a t e s of at l e a s t 0.5 d a y - 1 . The VP versus I» experiments attempted t o o b t a i n d i r e c t e s timates of parameters f o r a given c u l t u r e system, as a f u n c t i o n of the temperature and two c o n d i t i o n s of the n u t r i e n t s t a t u s - before n i t r a t e - d e p l e t i o n of the system and three days a f t e r the system had become n i t r a t e - l i m i t e d . ; Although the r e s u l t s i n d i c a t e d a s i g n i f i c a n t d i f f e r e n c e i n the s t a n d a r d i z e d p r o d u c t i v i t y r a t e s between temperatures, the d i f f e r e n c e between the two n u t r i e n t c o n d i t i o n s was not s t a t i s t i c a l l y s i g n i f i c a n t . I d e a l l y one would l i k e * P versus I * data a t v a r i o u s c o n c e n t r a t i o n s of n i t r a t e ; however, the v a r i a b i l i t y i n the i n f l o w H03 c o n c e n t r a t i o n t c the experimental system, combined with the n a t u r a l v a r i a b i l i t y i n SR and TEMP, d i d not provide c o n d i t i o n s f o r c o n t r o l l e d f a c t o r a l experiments. However, the e s t i m a t e s o f : t h e parameters p r e d i c t e d from a n o n - l i n e a r l e a s t sguares f i t of a TANH model, were used i n a phytoplankton s i m u l a t i o n model with success, p a r t i c u l a r l y i n the case of EXP5B (the experiment f o r which the estimates of PMAX, PTMAX and ALPHAC were based). The model p r e d i c t e d the dynamics and magnitude of the phytoplankton s t o c k a i d i l l u s t r a t e d the experimental time p e r i o d s when the p r o d u c t i v i t y was independent 103 of S H . _ The best f i t f o r the s i m u l a t i o n tuns f o r EXP5B was obtained using a constant value of 10.Q f o r PTMAX, which was determined from the * P versus I* data and agreed with the maximum i n s i t u values of ASS c a l c u l a t e d f o r the primary tank. Although the parameter CCHL was important i n determining the growth r a t e ( t - * ), only three r e p r e s e n t a t i v e values were were used i n the s i m u l a t i o n i n l i e u o f d i r e c t measurements: 30 f o r bloom c o n d i t i o n s with n u t r i e n t s u f f i c i e n c y , 60 d u r i n g the i n i t i a l post-bloom p e r i o d with n u t r i e n t d e p l e t i o n , and 45 during a s t e a d y - s t a t e p e r i o d . . These parametric e s t i m a t e s were s u f f i c i e n t l y s e n s i t i v e to p r o v i d e a c l o s e p r e d i c t i o n of the phytoplankton stock. , Even i n the t u r b u l e n t systems, the s i n k i n g r a t e was a s i g n i f i c a n t f a c t o r f o r about f o u r days a f t e r the system became n u t r i e n t - l i m i t e d . At the lower f l u s h i n g r a t e and i n the non-t u r b u l e n t one-stage c u l t u r e s , SINK was more s i g n i f i c a n t i n determining the s p a t i a l h e t e r o g e n e i t y of the phytoplankton. Consequently, the s i m u l a t i o n runs f o r EXP5A, with the v a r i a b l e f l u s h i n g r a t e , d i d not p r e d i c t the o s c i l l a t i o n s and magnitude of the phytoplankton stock as a c c u r a t e l y . , Ecwever, the other parameters i n the model sere a l s o a f u n c t i o n of FBr and e s t i m a t e s of t h e i r magnitude and v a r i a b i l i t y were more d i f f i c u l t to p r e d i c t . The r e s u l t s o f the h e r b i v o r e growth and s u r v i v a l d u r i n g the experiments i n d i c a t e d two main f e a t u r e s . F i r s t , the growth o f the s c a l l o p s was enhanced i n both t u r b u l e n t and non-turbulent systems with high f l u s h i n g r a t e s (> 0.5 day-*- provided t h a t the h e r b i v o r e s were l o c a t e d at a depth of 1.0 m to avoid high 104 l i g h t i n t e n s i t i e s . a comparison of EXP1 and EXP3B i n d i c a t e d t h a t the growth was probably l i m i t e d by temperature d u r i n g EXP1 {av TEHP=9.5 °C ) . , The growth r a t e of the s c a l l o p s reached a maximum of 16.8% at i n s i t u temperatures of 14.5 °C d u r i n g EXP3B (FB=0.75 day -* )• The growth environment even at 1.0 m was poor d u r i n g EXP2B (FB=0.25 day-* ) as a r e s u l t of the i n c r e a s e d temperature (15.6 day-* ), i n c r e a s e d S3 at depth and decreased phytoplankton stock i n t h i s c u l t u r e system. In c o n t r a s t , the c u l t u r e systems with a f l u s h i n g r a t e o f 0.25 day-* provided a s u i t a b l e environment f c r the growth of C r a s s o s t r e a gigas with a maximum growth r a t e of 1. 18 g/zoo/week f o r o y s t e r s ranging i n s i z e from 2.0 cm to 5.0 cm., I t was i m p o s s i b l e to estimate the s i g n i f i c a n c e of excreted ammonia i n a l l e v i a t i n g the n i t r o g e n - l i m i t a t i o n of p r i i t a r y p r o d u c t i v i t y . However, the o y s t e r growth during the one-stage c u l t u r e s appeared to be l i m i t e d by the phytoplankton stock. During the two-stage c u l t u r e of o y s t e r s (Experiments I to IV) , the growth r a t e of C r a s s o s t r e a .gigas was a f u n c t i o n of t h e i r d e n s i t y , t h e i r s i z e , and the type of phytoplankton provided as the food source (which was determined by the f l u s h i n g r a t e of the primary t a n k ) . The highest r a t e s were apparent i n the low d e n s i t y tank, which r e c e i v e d ca., 20.0 1/day per o y s t e r during EXPII and EXPIV., These p o t e n t i a l f i l t r a t i o n r a t e s were low compared with other feeding experiments f o r C r a s s o s t r e a (Balne, 1972; Tenore and Dunstan, 1973b)» flalne determined t h a t the average f i l t r a t i o n r a t e f o r 5.5 cm C r a s s o s t r e a gigas was about 6.5'1/hr i n a system with a FB=5. 0 day-* ., However, i n the o y s t e r experiments i n t h i s study (EXPI 1 0 5 t o EXPIV), the f l u s h i n g rate of the herbivore tanks was l i m i t e d by the flow r a t e from the primary tank. In order t o i n c r e a s e t h i s f e e d i n g r a t e i n a two-stage c u l t u r e , the volume of the primary tank would have t o be i n c r e a s e d , s i n c e an i n c r e a s e i n FK t o l e v e l s of 2.0 d a y - 1 only causes a 'wash-out* of the primary system.. In terms of s i z e , the h i g h e s t growth r a t e s were found i n t h e s m a l l e s t s i z e c l a s s , p a r t i c u l a r l y i n Experiment I I , when the o y s t e r s i n c r e a s e d i n weight by c_a. 21% i n one week. , & comparison between the f o u r h e r b i v o r e experiments d u r i n g EXP5 i n d i c a t e d two major f e a t u r e s . , F i r s t , the growth r a t e of the o y s t e r s was s i g n i f i c a n t but l e a s t during Experiment I I I (8.1%-per week). The h e r b i v o r e tanks were f e d a t a r a t e of 1.0 day-* with a n a n o - f l a g e l l a t e community which was promoted by a f l u s h i n g rate of 0.10 day-* in the primary tank. T h i s primary system provided a s u i t a b l e q u a l i t a t i v e food source, but the c o n c e n t r a t i o n of phytoplankton and maximum a t t a i n a b l e flow r a t e of the h e r b i v o r e tanks l i m i t e d the growth of the o y s t e r s . Furthermore, the high r e s u l t a n t temperature (>23 °C ) i n the h e r b i v o r e tanks dur i n g t h i s experiment was probably a s i g n i f i c a n t f a c t o r i n the r e d u c t i o n of the meat to s h e l l weight r a t i o . , Secondly, the o y s t e r growth i n the other three experiments averaged g r e a t e r than 10%/week. In each o f these experiments, the phytoplankton community was composed of diatoms, i n d i c a t i n g t h a t e i t h e r a 0.5 day-* or 1.00 day -* f l u s h i n g r a t e of the primary tank provided an e x c e l l e n t food source f o r the o y s t e r s . The h i g h e s t average growth r a t e s of 13.5%/week were a t t a i n e d i n the two-stage c u l t u r e d u r i n g Experiment I I . During t h i s 106 experiment, the C r a s s o s t r e a q i q a s Mere f e d at a f l u s h i n g r a t e o f 2.0 d a y ' frcm primary tank B (FB=1.Q day-* ), which c o n t a i n e d the highest c o n c e n t r a t i o n of CHLA dominated by Skeletonema  costatum . The temperature averaged 20.1 °C , which a c c o r d i n g t o Quayle (1969) i s optimal f o r the growth of c r a s s o s t r e a q i q a s , and the i n s i t u oxygen l e v e l s were s u f f i c i e n t f o r r e s p i r a t i o n . However, the growth of o y s t e r s i n the h i g h d e n s i t y tank appeared t o be l i m i t e d by the phytoplankton c o n c e n t r a t i o n . The data i n d i c a t e d t h a t 25 ug CHLA/day/g o y s t e r *as r e q u i r e d so t h a t growth was not l i m i t e d by the food c o n c e n t r a t i o n . At these f e e d i n g l e v e l s , growth r a t e s of 17.71/week c o u l d be achieved. An e x t r a p o l a t i o n of the r e s u l t s , i n c o r p o r a t i n g the f a c t t h a t the growth r a t e decreased with i n c r e a s i n g s i z e , i n d i c a t e d t h a t the experimental o y s t e r s would be a marketable s i z e of ca. , 60 g a f t e r another 3.5 months using the Experiment I I c u l t u r e system. The growth r a t e s i n t h i s c u l t u r e system were 15% g r e a t e r than the maximum f i e l d r a t e s measured by Quayle (1971) a t Ladysmith Harbour, the best o y s t e r growing area o f the s i x t e e n l o c a t i o n s t e s t e d i n B r i t i s h Columbia. Marketable o y s t e r s were obt a i n e d a f t e r two years, i n s t e a d of three or f o u r years a t the other s i t e s . However, although the growth r a t e s of C r a s s o s t r e a  gigas were high i n the continuous c u l t u r e system, approximately f o u r tanks (6m diameter X 1m deep) would be r e q u i r e d t o achieve the same production as one of Quayle*s r a f t s . T h e r e f o r e the economic f e a s i b i l i t y of growing o y s t e r s i n a c o n t r o l l e d c u l t u r e system should be assessed c a r e f u l l y . 107 CHAPTER 10. SOMH&BY JJJC COHCLDSJONS F i v e continuous c u l t u r e experiments were conducted to t e s t the h y p o t h e s i s t h a t production i n b i v a l v e food chains c o u l d be enhanced by using a deep n u t r i e n t - r i c h source of seawater and an opt i m a l f l u s h i n g r a t e and s p a t i a l s t r u c t u r e of the ecosystem to maximize p r o d u c t i v i t y . , The r e s u l t s i n d i c a t e d t h a t : 1. . The o p t i m a l f l u s h i n g r a t e to maximize p r o d u c t i v i t y i n a t u r b u l e n t system was 1.0/day. The system was n i t r a t e -l i m i t e d , and with n a t u r a l f o r c i n g c o n d i t i o n s of s o l a r r a d i a t i o n and temperature, a maximum phytoplankton stock of 60 ug Chi a 1 _ 1 was a t t a i n e d i n the one metre water column at i n f l o w n i t r a t e c o n c e n t r a t i o n s c f 25 uM H "1-* . Based on a compensation l i g h t i n t e n s i t y o f 18* the compensation depth f o r ; the system was c a . 3.0 metres i n d i c a t i n g t h a t at t h i s l e v e l of i n f l o w n i t r a t e , the f l u s h i n g r a t e c o u l d be reduced t o 0.33/day i n a 3.0 metre impoundment to maintain the same phytoplankton c o n c e n t r a t i o n . 2m.,. The chain diatom Skeletonema costatum dominated the ecosystem at the 1.0/day f l u s h i n g r a t e and was s e l e c t i v e l y grazed when fed t o the commercial o y s t e r C r a s s o s t r e a gigas . The maximum growth r a t e s o f the j u v e n i l e o y s t e r s were achieved when the he r b i v o r e tanks were f l u s h e d at a r a t e of 2. Q/day with the outflow from the primary tank (FE= 1.0/day) . The temperature was optimal f o r the growth of C r a s s o s t r e a gigas (20. 1 °C ) and oxygen l e v e l s were s u f f i c i e n t f o r r e s p i r a t i o n r e q uirements. y The growth r a t e of the o y s t e r s was 108 a f u n c t i o n of t h e i r s i z e , with the s m a l l e s t s i z e group having the maximum percent i n c r e a s e i n weight, and an average of 25 ug C h i a d y - * per gram o y s t e r was r e g u i r e d to achieve maximum growth r a t e s of 18%/week. 3. In terms of the a p p l i c a t i o n of the r e s u l t s to o y s t e r m a r i c u l t u r e , the growth r a t e s i n the optimal continuous c u l t u r e system were c a . . 152 g r e a t e r than the r a t e s i n an •optimal* f i e l d l o c a t i o n i n B r i t i s h C c l u m i i a . , A system of t h i s s i z e (7500 l i t r e s ) c ould support 250 c y s t e r s / m3 of a 10 gram s i z e , and provide a marketable crop at the end of the f i r s t growing season (when the o y s t e r s are ca. , 1.5 years old) . i 4. . At lower f l u s h i n g r a t e s (0.25/day), there was a decrease i n the st a n d i n g stock of phytoplankton i n d i r e c t p r o p o r t i o n to the decrease i n f l u s h i n g rate.,, although the i n s i t u c o n d i t i o n s , such as temperatere, sere favourable at t h i s f l u s h i n g r a t e , the growth of the o y s t e r s was l i m i t e d by the lower phytoplankton stock l e v e l s and a change i n the composition of the community from Skeletonema costatum to Chaetoceros sp. . 5. Higher f l u s h i n g r a t e s a l s o enhanced the pro d u c t i o n of the s c a l l o p food c h a i n , provided that the Chlamys hastat a h e r i c i a were grown at a depth of 1.0 metre to avoid high s u r f a c e l i g h t i n t e n s i t i e s . Maximum growth r a t e s o f 16.8% i n t o t a l weight per month were a t t a i n e d at a f l u s h i n g r a t e c f 0.75/day 1 0 9 when the i n s i t u temperature was 14.5 °C and the phytoplankton c o n c e n t r a t i o n { 29 ug Chi a l - 1 ) was not l i m i t i n g growth. However, under these c o n d i t i o n s , a f a s t e r growing s p e c i e s such as Patinopecten yessoensis would be p r e f e r a b l e f o r marieulture p r o d u c t i o n . €. at very high f l u s h i n g r a t e s of the primary system (2.0/day), the phytoplankton stock was washed cut of the tank and attached s p e c i e s , such as N a v i c u l a , dominated the system. The p r o d u c t i v i t y of N a v i c u l a a l s o i n c r e a s e d i n two other s i t u a t i o n s in.response, to higher l i g h t l e v e l s ; when the system was s t r a t i f i e d and a s i g n i f i c a n t p r o p o r t i o n o f the phytoplankton stock sank to the benthos, and secondly, when the g r a z i n g pressure of the i n s i t u h e r b i v o r e s reduced the phytoplankton stock to low l e v e l s . In c o n c l u s i o n , the l a r g e - s c a l e continuous c u l t u r e system provided a u s e f u l experime n t a l t o o l f o r examining the dynamics of n a t u r a l phytoplankton communities. a s i m u l a t i o n model, i n c o r p o r a t i n g e x p e r i m e n t a l l y determined parameters f o r primary p r o d u c t i v i t y and measured values f o r the f o r c i n g c o n d i t i o n s , p r e d i c t e d with reasonable accuracy the p a t t e r n and magnitude of the phytoplankton s t o c k , and could be used t o examine ecosystems with v a r i o u s f l u s h i n g r a t e s , s i n k i n g r a t e s and gr a z i n g r a t e s . 110 Table 1. Relevant c u l t u r e s t u d i e s of marine organic production i n terms o f t h e i r experimental design and c o n t r o l (*) S T O D Y j S O L E 01 |0EERATICK TEOFRIC jOPERAl. CCNIBCL SCOPE | TIME |SPACE 3 Haynes, 1 F i e l d j N a t u r a l 1 none | A. T. | Lake system 19731 1 food webj Gross et a l . , J F i e l d | N a t u r a l t batch | S c o t t i s h l o c h 195G| | food webf i n o r g 1 I. I a T. E» , ] F i e l d l cys 1 semi-c | 750 ac. t i d a l 1970 j J Salmon I n a t u r a l J impound ment 2.5X10m p l a s t i c T a k a i a s h i | LSC | Natural 1 batch J et al.,1975| | food webj i n o r g | c y l i n d e r Baab et a l , J LSC 1 P. Comm 1 cont ] Two-stage C u l t . 19731 J Oys 1 i n o r g | 45,0001 P.tank M c A l l i s t e r | LSC 1 P. Comm J none . ] isc ne | P l a s t i c sphere et al.,1961| J 1 (121 cu m) A n t i a et a l . , 1 LSC f P. Comm 1 none | A.I. J P l a s t i c sphere 1963J | 1 (12 1 cu m) Brown and J LSC | P. , , C C M 1 cont j OPVI . 1 1800 1 tank Parsons, 1972| | 1 i n o r g ] Goldman | LSC | P. Comm 1 cont j A. T. J 2000 1 tank et a l . , 1S75J 1 i n o r g ] Malcne et a l . , | LSC | P. Pop 1 cont J A.T. | 2000 1 tank 19751 1 i n o r g | 4 day exps. S t r i c k l a n d | LSC J P. Pop 1 batch | A.T. J 3m x 10m tank e t a l . , 1969i J I i n o r g | A n s e l l e t a l . , J LSC i p. pop 1 batch J A. T. j 1000 1 tank 19631 i 1 i n o r g 1 Tenore et a l . , j MSC \ Cys, 1 cont | 760 1 tank 1973J i Sea 11 ! p. CCBffl J 17 - 23 Deg C. Dunstan and 1 MSC 1 P. 'Comm 1 semi-c j A.T. | 400 1 tank Tenore, 1972J J \ org | 2 0 - 2 6 Deg C. , Dunstan and ] MSC I P. Ccmro I semi-c . | 400 1 tank Tenore, 1S74| | ! org 1 Tenore and j SSC 1 Oys, 1 cont ] 9 1 t r a y s Dunstan, 1973al I S c a l l 1 p. comm j Ep i f a n c and j SSC 1 oys 1 cont | 100 1 tank Mootz, 1976 j I i p. pops | ( x e c i r c i l a t . ) Halker and J SSC 1 Oys I cont i 10 1 raceway Zahradnik,1976] 1 nat.comm] (. Ix. 1x1. 0 m) Kirby-Smith S \ SSC | S ca 11 1 cent j 3 1 racevay Barber, 1S74j 1 nat.comm| (. 3X.2X.C5 m) Ketchum | SSC | P. .Pops 1 semi-c J A.T. | 8 1 f l a s k e t a l . , 1949| 1 1 i n o r g j COMMENTS * SCALE CF OPERATION: LSC (large s c a l e c u l t u r e - >1000 1) ;MSC (medium s c a l e c u l t u r e - 100-1000 1 ) ; SSC (small s c a l e c u l t u r e - <1C0 1) TEOPHIC SCOPE: P. (primary); Pop ( p o p u l a t i o n ) ; Coram(cemmunity); Oys (Oys t e r ) ; S c a l l ( S c a l l o p s ) TIME (Bate of a d d i t i o n ) : batch;semi-c(semi-continuous);cont (contin) TIME (Form of n u t r i e n t ) : i n o r g (inorganic) ; org (organic) ; P. (phytopl.), SPACE: A . T . ( a r t i f i c i a l turbulence) ;UPW(upwelling) ;blank (net spec.) 111 Table 2. D e s c r i p t i v e s t a t i s t i c s summary of s e l e c t e d v a r i a b l e s f o r EXP2A, i n c l u d i n g a breakdown i n t o the p i e - g r a z i n g and grazing p e r i o d . Day 37 and 40 .measurements f o r CHLA, PBGC and ASS have been excluded frcm the s t a t i s t i c s f o r a d i r e c t comparison with EXP2E. The s t a t i s t i c s f o r CHLA and ASS are a l s o given f o r the gr a z i n g period corresponding to EXP3A. TOTAL EXP1EIMINT PRE-GRAZING GRAZING PEE.IGD (t =1,41) (t=1,6) (t=7,41) V A fi 1 STN 1 N MEAN S.D. | N MEAN S. D. | N MEAN S.D. SR J I 41 410. 114. J 6 380. 165. 35 410. 112. SAL I I I 41 28.3 0.61 | TEMI 1 1 41 11.0 G.87 | 6 9.6 0.50 .35 11.2 G.68 I s I 4 1 17.0 2.60 I 6 14.4 3.47 | 35 17.5 2.17 | M | 41 16.2 2.26 J 6 13.3 2.79 35 16.7 1.76 1 E I 41 15.4 1.62 | 6 13.2 2.66 j 35 15.8 1.02 1 '0 41 17.0 2.61 j 6 14.7 3.88 j 35 17.4 2. 17 NC3 | I | 41 18.2 3.62 | 6 23.3 1.72 l 35 17.3 3.C8 1 s 6 15.4 10.ce 35 G.5 C.59 1 H 6 15.0 10.49 35 0.4 0.34 I E 6 15.4 S.78 | 35 0.4 0.55 1 0 6 15.0 10.04 35 0.3 C.36 NH3 1 I | 41 0. 77 0.43 | 1 s 41 0.50 0.42 | 1 K | 41 0. 42 0.3 2 | 1 B | 41 0. 64 0.48 | I o | 41 0. 47 0.31 | OXY 1 I I 41 7. 50 0,39 I 6 7.09 0.17 35 7. 57 C .06 1 s I 41 11. 41 2.60 | 6 9.37 3.57 35 11.76 2.28 ] M I 41 11.76 2.82 | 6 9.22 4.01 I 35 12. 19 2.38 1 E | 41 11. 72 2.76 | 6 9.08 3.S5 35 12. 17 2.28 I 0 | 41 11.26 2.24 J 6 9.72 3.29 35 11.52 1.S6 SAT 1 I I 41 82. 5. 1 | j S I 11 141. 33.2 | 1 B | 41 113. : e C i i B I 41 140. 34.1 j CBLA 1 s I 18 5.2 6.4 2 | 6 8.8 10. 12 12 . 3.3 2.48 i B J 18 7.2 10.83 f 6 13.2 17.60 I 12 4.2 3.35 1 E I 18 9.5 11.88 J 6 14.9 19.71 | 12 6.8 4.21 1 o I 18 5.6 6.50 . | 6 8.5 10.06 | 12 4.1 3.46 1 s I 7 4.3 2.55 J M I 7 5.4 3.81 1 E I 7 6.2 3.S4 1 o 7 5. 1 3.86 EBCD 1 s I 14 20.2 | M | 14 28.6 1 E \ 14 32. 1 ASS 3 S | 14 4.9 2.3 5 | 3 3.5 2.27 11 5.3 1 H \ 14 5.2 1.8 8 i 3 3.3 1.67 |. 11 5.7 i B I 14 4.1 2.15 | 3 2.7 1.27 I 11 4.5 I s I 6 5.7 2.76 | M I 6 5.8 1.91 1 E I 6 . 5.0 2.91 1 1 2 Table 3 . D e s c r i p t i v e s t a t i s t i c s summary of s e l e c t e d v a r i a b l e s f o r E X P 2 B , i n c l u d i n g a breakdown i n t o the pre - g r a z i n g and g r a z i n g p e r i o d . See Appendix 1 f o r a d e f i n i t i o n of the v a r i a b l e names. The s t a t i s t i c s f o r C H L A and ASS are given f o r the corresponding time p e r i o d s i n E X P 2 A . T O T A L E X P E E I K E N T P H E - G B A Z I N G G R A Z I N G P E E I O D ( t = 1 , 3 4 ) ( t = 1 , 1 0 ) ( t = 1 1 , 3 4 ) V A B | S T N 1 N M E AN S . C . | N M E A N S . D . | N' M E A N S . D . S B | I 3 4 1 2 0 . 1 4 7 . .] 1 0 3 9 0 . 1 7 2 . i 2 4 4 2 0 . 1 3 9 . S A L I I 1 3 4 2 8 . 3 0 . 6 7 | 1 0 T E M P i i | 3 4 1 0 . 8 0 . 8 6 ] 1 0 9 . 9 0 . 6 1 I 2 4 1 1 . 2 0 . 6 4 t s | 3 4 1 7 . 2 2 . 7 7 | 1 0 1 5 . 4 3 . 1 1 | 2 4 1 7 . 9 2 . 2 9 j M I 3 4 1 6 . 4 2 . 5 8 | 1 0 1 4 . 3 2 . 5 9 j 2 4 1 7 . 2 2 . 0 9 I E 1 3 4 1 5 . 1 1 . 6 8 j 1 0 1 4 . 0 2 . 3 0 | 2 4 1 5 . 6 1 . 1 1 | 0 | 3 4 1 7 . 0 2 . 7 2 | 1 0 1 - 5 . 3 3 . 1 9 2 4 1 7 . 7 2 . 2 0 N C 3 | I 1 3 4 1 8 . 8 3 . 5 8 1 0 2 2 . 6 2 . O S 2 4 1 7 . 2 2 . 7 8 1 c 2 4 0 . 5 0 . 4 5 J M 2 4 0 . 4 0 . 4 0 J B 2 4 1 . 1 1 . 5 4 1 G 2 4 0 . 4 0 . 4 3 N H 3 J I l 3 4 G . 7 1 0 . 4 2 | J s 1 3 4 0 . 5 8 0 . 4 9 j 1 M | 3 4 0 . 6 7 0 . 4 4 | i E 1 3 4 6 . 5 0 0 . 3 1 | i o | 3 4 0 . 6 5 0 . 6 1 | O X Y 1 I | 3 4 7 . 5 2 0 . 5 2 1 0 7 . 1 9 0 . 2 9 2 4 7 . 6 5 0 . 5 4 1 s I 3 4 1 1 . 4 5 2 . 7 9 J 1 0 1 2 . 0 3 4 . 2 9 2 4 1 1 . 2 1 1 . 9 3 | M | 3 4 1 1 . 5 7 2 . 9 4 j 1 0 1 2 . 1 1 4 . 3 1 2 4 1 1 . 3 5 2 . 2 3 1 B | 3 4 1 0 . 5 1 3 . 1 0 | 1 0 1 2 . 0 7 4 . 3 3 2 4 9 . 8 6 2 . 2 2 1 o | 3 4 1 1 . 3 9 2 . 4 3 1 0 1 1 . 6 9 3 . 7 2 2 4 1 1 . 2 7 1 . 7 3 S A T I I | 3 4 8 1 . 6 . 5 | 1 s | 3 4 1 4 1 . 3 4 . 6 j I M | 3 4 1 4 0 . 3 5 . 9 | 1 E | 3 1 1 2 5 . 3 7 . 2 C f l L A 1 s | 1 8 6 . 8 9 . 6 9 | 9 9 . 0 1 3 . 0 0 9 4 . 8 4 . 4 0 I M | 1 8 9 . 7 1 0 . 9 5 ] 9 1 3 . 7 1 4 . 0 4 | 9 5 . 6 4 . 5 9 i B | 1 8 1 0 . 3 1 0 . 8 3 | 9 1 4 . 0 1 3 . 6 5 j 9 6 . 6 3 . 3 9 ] c I 1 8 8 . 8 9 . 8 2 I 9 1 2 . 1 1 2 . 4 5 9 5 . 9 4 . 6 4 C H L A 1 s 6 1 0 . 6 1 6 . 0 5 1 2 4 . 5 1 . 0 3 1 M 6 1 1 . 7 1 6 . 0 6 j 1 2 8 . 6 8 . 0 3 1 E 6 1 2 . 0 1 5 . 7 2 1 2 9 . 4 7 . 2 0 1 G 6 1 1 . 1 1 5 . 3 3 1 2 7 . 6 6 . 1 5 P B O D i s | 1 4 2 7 . 1 -1 M | 1 4 3 2 . 3 1 E | 1 4 4 4 . 4 A S S 1 s 1 1 4 5 . 3 2 . 3 9 5 4 . 4 2 . 3 6 9 5 . 8 2 . 1 1 i M I 1 4 5 . 3 3. 13 -1 5 4 . 0 1 . 9 5 I 9 6 . 1 3 . f 2 1 E f 1 4 6 . 2 4 . 6 5 c • 5 . 9 5 . 6 6 I 9 € . 3 4 . 3 7 A S S \ s 3 4 . 6 3 . 1 7 1 1 5 . 5 2 . 2 9 J M 3 4 . 1 2 . 1 2 1 1 5 . 7 3 . 3 2 i B 3 4 . 0 2 . 6 5 [ 1 1 6 . 8 • 1 . 5 1 113 Table 4. Results of the oy s t e r growth during Experiment 21. GRWM and GR1S, r e f e r to the growth r a t e of the meat and s h e l l weights per o y s t e r per week f o r a comparison with EXP 3 A and EXP .5. MSB ATI C i s the r a t i o between NETWM and NETWS. SURF ACE DEPTH SUESTN NETWT NETWM PERWK GRHM NETWS GBWS MSEATIO 1 81.0 11.0 17.3 0. 16 70.0 1.00 . 162 2 88.5 19.5 26.0 0.24 65.0 G.€6 .283 3 55.5 14.0 22.4 0.23 41. 0 0.68 .311 4 65. 8 14.0 25.9 0.28 51.5 1.03 .272 .MID DEPTH SUESTN NET1T NETWM PIEWM GRWM NETWS GRWS MSEATIO 1 68.5 11.5 11.6 0.16 5 7.0 0.81 . 202 2 88.0 23.5 36.4 0. 28 64,5 0.76 .364 3 78.0 22.5 36.6 0.30 55.5 0.74 .405 4 81.5 16,0 15. 2 0.25 65.5 0,80 .244 EOTTCP DEPTH SUESTN NETWT NETWM PEEWM GRWM NETWS GliWS MSRATIG 1 52.5 12.5 14, 1 0.23 4 0.0 0.73 .313 2 111.5 23, 5 25,1 0.31 8 8,0 1.17 .267 3 98.0 24.0 23.3 0.28 74.0 0.87 .324 4 40. 0 10.5 10.9 0. 19 29.5 0.54 .356 114 Table 5. Growth of the s c a l l o p s d u r i n g Experiment 2B, See Appendix 2 f o r an e x p l a n a t i o n of the v a r i a b l e s . MID STATION SOESTN NSUBV I SD PEEL W SD .PEHW 1GTT SD PEBRT 1 4/8 5. 0 .58 0.5 4.4 .58 2, 0 16. 1 4.36 -0.2 • 2 4/8 5. 6 . 19 - 1.0 5.1 .20 0. 1 23,5 0.51 . 1 . 1 3 3/8 6. 1 .35 -0.1 5.4 .32 1.7 29.8 3.33 -0.6 4 3/8 6. 8 .38 -0.2 6.2 .44 -0.5 43.8 6.62 -1,7 BOTTOM STATION SOBSUN NSURV L SD FEE I SD PEEW SGTT SD PER ET 5 8/8 4.7 .59 0.3 4.2 .62 0.7 13.8 4.11 -9.6 8 8/8 5. 6 .27 0.1 4.9 .25 0.3 22.0 3,10 -6.S 9 8/8 6. 1 . 22 0.0 5.6 .21 0.3 32.5 3.77 -5.0 12 8/8 6.7 .35 -0.3 6.1 .43 0.0 44. 3 6.76 -10 . 5 1 1 5 Table 6. D e s c r i p t i v e s t a t i s t i c s summary o f s e l e c t e d v a r i a b l e s f o r EXP3Aj i n c l u d i n g a breakdown i n t o the p r e - g r a z i n g and g r a z i n g p e r i o d . See appendix 1 f c r a d e f i n i t i o n of the v a r i a b l e names. TOTAL EXPERIMENT PRE-GRAZING GRAZING PEEIOD (t=1,21) (t=1,6) Jt=7,21) VAR | STN I N MEAN SD | N MEAN SB J N . Ml AN SD SR | I 21 330. 104. | 6 400. 55. . j 15 300. 108. TEMP l I I 21 11.6 1.36 I 6 11.1 0. 17 | 15 11.8 1.58 J S I 21 16.3 G.S6 | 6 15.9 0.49 | 15 16.4 1.08 I M |21 16.2 G.92 | 6 15.8 0.54 | 15 16.4 1.00 I B | 21 16.2 0.89 | 6 15.8 0*49 | 15 16.3 0.9 8 I o I 21 16.2 C.98 | 6 15.8 0.46 | 15 16.4 1.09 NO 3 i I I 21 21.0 2.05 | 6 20 .4 1.35' | * . N/ft NB3 i I I 21 0.50 0.28 J i s I 6 0.40 0.29 | f M I 6 0.34 0.31 J t E I 6 0.27 0.17 J t o I 21 0.50 0.50 | OXY i i I 21 7. 04 0.72 J 6 6.73 0.13 15 7.16 €.78 I s I 21 9.91 1.89 \ 6 10.50. 2. 84 J 15 9.68 1.41 I M I 21 9. 88 1.9 1 | 6 10.56 2.£€ 1 15 9.60 1.40 I B I 21 9.97 2.51 | 6 10.54 2.84 15 9.74 1.75 I o I 21 9. 9 2 1.69 | 6 10.36 2.62 | 15 9.74 1.23 CHLA I s I 13 10.4 9.7 4 J 6 13.9 12.7G 7 7.3 5.69 I M I 13 11. 1 11.20 j 6 15.8 14.80 | 7 7.2 5.34 ! B 1 13 11.5 11.42 | 6 16.2 14.99 j 7 7.5 5.78 I "0 | 13 1 1. 2 11.50 | 6 16 . 0 15.10 | 7 7.1 5.64 PROD I s i 9 25.0 19.09 \ I M I 9 29.3 2 1.94 | I B i 9 27.2 16.83 I ASS i s \ 9 3.4 1.98 | 3 2.3 C.55 ; 6 4.0 2 .18 | M I 9 3.8 2.33 | 3 2.8 1.80 6 4.3 2.55 i E | 9 3. 9 2.71 | 3 2.2 1.23 | 6 4.7 2.S4 116 Table 7. J e s u i t s of the o y s t e r growth during Experiment 3fl. GBWK and G.BHS r e f e r to the growth r a t e c f the meat and s h e l l weights per o y s t e r per seek f o r a comparison with EXP2A and EXP 5. MSB il TIC i s the r a t i o between KET«H and NETWS. SUBFACE DEPTH SUESTN NET AT NETWM PIBWM GBSM NETHS GBHS MSB ft TIG 1 18.5 4,8 4.4 0. 12 14.5 0.45 .276 2 9.5 2.0 1.4 0.06 7.5 0.25 .267 3 8.0 2,0 1.9 0.08 6.0 0.25 .333 4 16.5 2.5 3.8 0.13 14.0 C.7C .179 5 16.5 0.5 C.8 0.02 16.0 0.53 .031 6 6.5 1.0 2.6 0.03 5.5 G.20 .182 7 24.5 11.0 11.2 0.61 13.5 0.15 .815 8 28.0 5.0 «f.3 0.21 23.0 0.S6 .217 MID DEPTH SUESTN NET ST NETS M IE EH B GBSM NET1S GESS MSBSTIC 1 6.5 2.0 3.5 0. 10 4.0 0.20 .500 2 19.5 2.5 1.8 0,08 17 . 0 0.50 . 147 3 12.0 2.0 3.3 0.0 9 10.0 0.46 .200 4 2.C 1.0 2.4 0.05 1.0 0.05 1.000 5 11.5 4.5 7.2 0. 18 7.0 0.27 .643 6 8.0 0.5 0.8 0.03 7.5 0.47 .067 7 9.5 2.0 2.9 0.08 7.5 0.31 .267 8 7.5 1.0 1.5 0.04 6.5 0.27 .154 BOTTOM STATION SUESTN NET8T NETWM PEBH M GB8M NETWS GBSS MSEATIG 1 31.0 5.2 4.4 0. 18 25.8 C.92 .202 2 9.5 4.0 6.5 0. 12 5.5 0.17 .727 •3 18.5 2.0 3.5 0.08 16.5 0.69 .12 1 4 30.0 7.0 10.9 0.23 23.0 0.77 .304 • 5 27.0 5.5 7.1 0.30 21.5 1. 19 .256 6 4.0 2.0 2. 2 0.06 2.0 0.06 1.000 7 24,5 7.5 4.8 0.22 17.0 0.50 .44 1 8 25.0 10.0 10.6 0.6 2 15.0 0,47 .667 117 f a c i e 8. D e s c r i p t i v e s t a t i s t i c s summary of s e l e c t e d v a r i a b l e s . f o r EXP3B, i n c l u d i n g a breakdown i n t o the p i e - g r a z i n g and g r a z i n g p e r i o d . See Appendix 1 f o r a d e f i n i t i o n of the v a r i a b l e names. . TOTAL EXPERIMENT PBE-GBAZING GRAZING EEE.IOD (t=1,34) <t=1,11) (t=12,34) V8R I STN , 1 N MEAN SD J N MEAN SD | N MEAN S D SB I I 1 34 380. 105. \ 11 410. 102. „ i 23 366. 106. TEMP J I 1 34 11.4 G.52 | 1 1 11.5 0.32 | 23 11.4 0.59 1 s 34 14.9 1.05 | 11 15.5 0.78 | 23 14,5 1.02 ] M 1 34 14.8 1.04 J 1 1 15.5 0.7 6 | 23 14.5 1.02 J B | 34 14.8 1.04 | 11 15.5 0.74 | 23 14.5 1.01 1 0 1 34 14.8 1. 10 | 11 15.5 0.63 I 23 14.5 • 1.06 NG3 1 I 1 34 19.3 2.02 | 11 18.9 1.26 23 19.6 2.29 I ' S J 23 0.3 C.37 i H ' | 23 0.3 0.34 1 E | 23 0.3 0.38 1 o 23 0.2 0.3 2 NH3 1 I I 34 0.42 0.29 J i s 1 11 0.59 0.47 J 1 B I 11 0.61 G. 35 | 1 E | 11 0.60 0.31 | i o | 34 0.48 0. 18 I OXY 1 I | 34 6. 98 0.54 J 11 6.93 0.2 1 23 7.01 C.65 1 s | 34 11.49 1.59 | 11 10.39 2. 14 23 12.01 o . s o 1 M I 34 11.52 1.58 | 11 10.44 2. 18 23 12.03 0.€4 1 E | 34 11. 46 1.54 J 11 10.42 2. 16 23 11. S6 0.79 1 o | 34 11.31 1.40 | 1 1 10.41 2.05 j 23 11.7.4 0.66 CHLA 1 s 1 18 22. 1 12.37 | 9 14. 9 13.70 | 9 29.2 4.67 ] M | 18 22.8 12.54 | . 9 15.8 14. 48 9 29.7 4.08 . I E | 18 22.6 12.55 | 9 15.2 14.14 j 9 2S.9 3.56 i o ] 18 23.0 12.78 | 9 16.2 15.06 9 29.7 4.20 EIOD 1 s I 14 38.3 13,86 | 1 M | 14 36.9 14.98 | 1 E I 14 39.8 19.79 J ASS I s | 14 2.4 2.11 | 5 4.4 2.51 9 1.2 0.28 1 H I 14 2.2 2.13 | 5 4.3 2,5 9 j 9 1.1 0.10 j B 1 14 2.3 2.13 | 5 4.4 2.33 9 1.0 0.26 Table 9. Growth cf the s c a l l o p s d u r i n g Experiment See Appendix 2 f o r an e x p l a n a t i o n c f the v a r i a b l e s . SURFACE STATION SOBSTN NSUBV L SD PES I M SD PEBW KGTT SB PEE ST 6 0/8 3.6 .23 N/a 3.1 .19 N/fl 6.0 1.08 . N/A 7 0/8 4, 3 .39 N/A 3.8 .41 . N/A 10.6 2.89 N/A 10 0/8 5.4 . 19 N/A 4.8 .17 N/A 19.4 1.27 N/A 11 0/8 5.8 .44 N/A 5.2 . D2 N/A 26.3 4.83 N/A MID STATION SUESTN NSUBV 1 SD PEEL « SD PEEW KGTT SD PEEST 1 3/8 3.6 .22 0.3 3.1 .19 -0. 1 6. 2 1. 12 -0.4 2 4/8 4„2 .29 0.0 3.7 .19 0.1 S.8 1.35 -1.9 3 6/8 5.2 .31 0.3 4.7 .32 1.6 18.3 2.48 1.6 a 5/8 5.9 .53 '• G.2 5.3 .51 0.2 26.6 6.92 0.8 BOTTOM STATION SUESTN NSUBV L SD PEEL H SD PERW KGTT SD PES«T 8 7/8 3„8 .45 1.8 3.3 .42 0.5 6.3 1.82 11.7 5 8/8 4.5 .27 1.0 t).0 .26 1.0 11.4 1.11 14.4 9 8/8 5. 1 .15 0.4 4.6 .20 0.3 16.9 2.87 16.8 12 8/8 5.7 .31 0.4 5. 1 .34 0.5 2 5.4 4.23 1.2 119 • f a b l e 10. Pearson c o r r e l a t i o n c o e f f i c i e n t s between the f o r c i n g v a r i a b l e s during Experiment 4 f o r bcth Tank a (upper r i g h t ) and Tank E (lower l e f t ) . The v a r i a b l e s i n c l u d e : i n c i d e n t s o l a r r a d i a t i o n , SB (ly/day) ; i n f l o w temperature, TEMP (deg-C.);, i n f l o w n i t r a t e c o n c e n t r a t i o n , K03 ( u E / l i t r e ) ; and inflow oxygen c o n c e n t r a t i c n , OXY (ng/1i t r e ) . As the p r e f i x A i n the v a r i a b l e name i n d i c a t e s , the v a r i a b l e s were ' f i r s t averaged', sc that AVAE = 0.5*(VABt + V'fiBt+1), f o r a comparison with the d a i l y i n t e g r a t e d s c l a r r a d i a t i o n , S B . SB has been lagged one to three days (SB1 to SB3) to examine the s e r i a l c o r r e l a t i o n f o r s o l a r r a d i a t i o n . EXP 4 A v SB ATEMP A NO 3 AOXY SB1 SB 2 SB3 A E 4 SE E . 118 t=3 3 S=.512 .065 t=33 S=,.6 40 .345 t=33 S=.050 .422 f=32 • S=.C16 -.118 t=31 £=.528 -.433 t=3C £=.0 16 A TEMP .080 t = 33 S=.660 -.769 t=33 S=.0O2 .678 t=33 £=.002 AN03 .008 t=33 S=.964 -.844 t=3 3 S=.002 -.598 t=33 £=.002 -. 137 t=32 S=.456 -.364 t = 31 S=,044 -.365 t=3 0 £=.0 48 AOXY .356 t=33 S=.042 .662 t=33 S=.002 -.657 t=33 S=.C02 SE 1 .422 t=32 £-.016 -. 13 7 t=3 2 S=.254 SB 2 -.118 t = 31 S=.528 -.33 2 t=31 S=.068 -.433 SB3 t=30 S=.016 -.307 . t = 3 0 S=.098 120 Table 11, Descriptive s t a t i s t i c s of .'selected,, variables' for 1XP4A, including s t a t i s t i c s for the n i t r a t e -depleted period (t=29). See appendix 1 for the d e f i n i t i o n of the variable -names,,. van STN T Ml. AN S a D . S . E . ., C.v. E A NGE M a x SH I 34 378, 149.7 25.7 3S.6 453. . 564, SAL I 34 27.3 0.79 0. 14 2.9 3.0 26.5 TEMP I 34 10.4 0.41 0,07 3,9 1.3 11.1 S 34 14.7 1.29 0.22 8.8 4.1 1.6.6 M 34 14. 6 1.2 6 0.22 €.6 4.1 16.3 B 34 13. 1 1.54 0.26 11.8 5.1 16. 1 0 34 14.6 1.30 0.22 €.9 4.4 16.5 TEMPTS S 34 4.3 1.32 0. 23 30.7 '.. 4.9 •6. 1 M 34 4.2 1.28 0.22 30.5 4.9 6.1 B 34 2. 7 1.41 0.24 52.2 4.9 5.3 0 34 4.2 1.3 2 .0, 23 31.4 .' ,5.0 6.1 WO 3 . I 34 18.8 2.56 0.44 13.6 9.5 22.2 OXY I 34 7.58 0.682 0.117 S.C 3.23 9.S7 : s . 34 10.85 1.364 ,0.234 12.5 5.04 13.26 M 34 10.90 1.406 0.241 12. $ 5.20 13.69 B 34 8.98 1. 163 0. 199 12.9 ' 5.03 11.01 0 34 10,69 1. 179 0.25 4 13.8 5.S5- 13.28 OXYN S 34 3.26 1. 824 0.313 56.0 6.40 6.21 M . 34 3.32 1. 822 0.312 51. S 6.73 6.81 B 34 1.39 1, 06 2 0. 182 76.4 4.34 2.S 1 0 34 3.11 1.691 0,324 6 0 . 8 6.53 6.10 saT I 34 81. 7.6 1.3 S.4 35. 107. S 34 126. 17.7 3.0 14.0 65. 160. E 34 127. 18.1 3.1 14.3 66. 163. B 34 102. 15,2 2.6 14.S 6 8. 131. 0 34 125. 18.8 3.2 15.0 74. 160. CHLfl S 34 15.4 7.20 1.23 46.6 28.6 28.9 a 34 15.4 7.09 1.22 46.0 25.3' 2 5.4 . B 34 18. 2 8.82 1.51 48.5 33.1 33.2 0 34 16.3 7.82 1.34 48.0 30.7 3 0.8 SB i 29 358, 149,0 27.7 11.6 445. . 55'6. TEMP i 29 10.4 0.39 0.07 3.8 1.3 1-1.1 S 29 14.7 1.27 0.24 8.6 4.0 16.6 M 29 14.6 1.23 0.23 8.4 3.7 1 & B 29 12.8 1.39 0.26 10.8 5.1 16.1 0 29 14.6 1.27 0.24 8.7 3-9 16.5 TEMP N s 29 4.3 1.28 0,24 2S.8 4.1 €.1 M 29 4.2 1.24 0. 23 29.5 4. 1 €. 1 B 29 2.4 1.30 0.24 54.2 4.9 5.3 0 29 4.3 1.28 0.24 29.8 4. 1 t. 1 N03 .1 29 19.0 2.6 5 0.49 13. 9 9.5 22.2 N03N s 29 18.7 3.06 0.57 16.4 10.5 22.2 M 29 18.S 2.81 0.52 14, S 10.6 2 2.2 B 29 15.3 5.56 1.03 36. 3 24.5 22. 1 1 o 29 18. 1 2.98 0.55 16.5 13.1 22.2 OXY I 29 7.47 0.669 0. 124 • S.O 3.23 . 9 . 97 s 29 11,20 1. 14 2 0.212 10.2 3.76 13 .26 H 29 11.30 1. 112 0.207 S.8 4. 08 13.69 ;12'1 I B. 29 8 , 9 3 1. 251 0.232 13..S 5.03 11.01 0 29 11,04 1.306 0.243 11.8 5.95 13.28 OXYN • s 29 3,73 1.5.33 0.285 41.1 6.40 6.21 29 3.83 1.439 0.267 37.6 5.69 6.8 1 !' B • 29 1.53 1.080 0. 201 10.6 4.34 2.91 ! o 29 3.5 8 1.632 0.303 45.6 6.53 6.40 S A T I I 29 79. 7.4 1.4 9.3 35. 101. s 29 131. 15.6 2.9 11.9 52. 160. I H 29 132. 1-5.3 2.8 11,6 • 55. 163. ; B 29 101. 16.2 3.0 16.0 68. 131. 0 29 129, 17.2 3.2 13.3 74. 160. CHLA l " s 29 17.2 5.37 1.00 31.2 22. 1 2 8.9 r M 29 17. 2 5. 16 0.S6 3 0,0 16. S 2 5.4 B 29 20.5 6.74 1.25 3 2-9 23.6 3 3 . 2 I o 29 18. 3 5.90 1.10 32.2 22.6 30.8 CHLE j s 29 .1.4 0.70 0. 13 50.0 2.6 5.7 I • M 29 1.4 0.80 0, 15 51.1 3.2 3.2 B 29 2.3 1.18 0.22 51. 3 4.6 5.2 I o 29 1. 4 0.80 0.15 51. 1 3.2 3.4 CHLC I ' s 29 11.0 2.93 0.54 26.6 12.4 18.2 I .fit 29 12.2 3.4 9 0.65 28.6 14.4 20.7 B 29 12.1 4.01 0.74 3 3. 1 13.6 18.0 I . .0 29 11. 1 2. 97 0.55 26.8 12.1 11.2 C l I. s 29 21.8 6.76 1.26 31.0 24.8 35.8 | H 29 2 1.6 6.00 1. 11 27.8 19.9 3 1.6 B 29 2 3.2 7,08 1.32 30.5 29.8 4 2.5 I , 0 29 23.2 7.26 1.35 31.3 27.2 31,0 E A I 1 . 105 |. S 29 .092 .049 .009 53.3 .188 .154 ! H 29 .086 .051 .010 59. 3 .202 a 20 2 ! B 29 .119 .014 .014 62.2 : .395 .400 I ' o. 29 .081 .046 .009 56.8 .201 .210 CA I . I 1 1. 153 I s 29 .660 .105 .020 15,9 .35 8 .652 I n 29 .634 .115 .021 18.1 .405 . ES3 B 29 .598 .103 .019 17.2 .402 .168 I o 29 .624 .057 .018 15.5 .481 .943 C T A I 1 1.123 t • s 29 1. 283 .209 .039 16.3 .768 1.127 I. , M 29 1.277 .196 .036 15.3 .677 1. €09 I E 29 1. 153 .15 2 .028 13,2 .599 1.5(17 I o 29 1.274 -159 .030 12.5 .573 1. 590 EC I I 1 . OS 1 j ' s 29 .136 .065 .0.12 47.8 .257 . 267 I H 29 .13 2 .013 .014 55.3 .255 .259 i B • 29 .200 .112 .021 56.0 -•..553 . 561 I o 29 . 127 .065 . 012 51.2 .207 .223 ECT I i : 1 .093 l s 29 .073 ,038 .007 52.1 .135 .140 I H 29 , . 06 8 .038 .007 55.9 . 135 . 135 i B 29 . 102 .055 .010 53. $ .288 . 293 I o 29 . 065 .037 .007 56. 9 . 161 .16 8 CCT I I 1 1.027 i s 29 .526 .110 .021 20.9 .45 4 .119 | B 29 .510 .128 .024 25. 1 • .559 .£62 I • B 29 .521 .072 .013 13.8 .301 .646 I o 29 .486 .057 ,018 19.6 .459 .154 122 Table 12, D e s c r i p t i v e s t a t i s t i c s of s e l e c t e d v a r i a b l e s f o r FXP4E, i n c l u d i n g s t a t i s t i c s f o r the n i t r a t e -d epleted p e r i o d (t=27). See Appendix 1 f o r the d e f i n i t i o n of the v a r i a b l e canes. VfiB STN T MI AN S.D. S. E. , C.V. BANG! fi 2 X SB I 34 378. 149.7 25.7 39.6 453. 561. SAL I 34 27.3 0.79 0.14 2.9 3.0 2 6.5 TEMP I 34 10.4 0.39 0.07 3.8 1.3 11.1 S 34 13.0 0.78 0. 13 6.0 2.4 14.2 M 34 13.0 0.76 0.13 5.8 2.4 14.2 B • 34 13.0 0.76 0.13 5.S 2.5 14.2 0 34 13.0 0.78 0.13 6.0 2.5 14.3 TEH FN S 34 2.7 0.76 0. 13 28. 1 2.7 3.7 M 34 2.6 0.14 0.13 28.5 2.6 3.6 B 34 2.6 0.76 0. 13 29.2 2.6 3.6 I 0 34 2.6 0.76 0.13 29.2 2.6 3.8 N03 I 34 18.7 2.87 0.46 15. 3 11.3 2 2.7 OXY I 34 7. 55 0.670 0.115 e.s 3.23 9.S7 S 34 11.58 1.645 0. 282 14.2 5.61 14. 13 M 34 11.48 1.653 0.284 14.4 5.41 13.S6 B 34 1 1.28 1.679 0.288 14. 9 5.72 14.30 0 34 11.27 1. 487 0.255 13.2 5.2 0 13.75 OXYN S 34 4.03 1.904 0.327 47.2 6.7S 6.67 H 34 3. S3 1.903 0. 326 48.4 6.60 6.74 B 34 3.70 1.835 0.315 49.6 5.92 6.02 0 34 3.71 1.711 0.293 46.1 5.66 6.00 SAT I 34 80. 7.4 1.3 9.2 36. 107. I s 34 . 131. 18.9 3.2 14.4 67. 164. M 34 130. 19.0 3.3 14.6 70. 1€5. I B 34 127. 19.0 3.2 15.0 61. 158. 0 34 127. 17.2 2.9 13.5 67. 165. CHLA |- . s 34 31.5 15.93 2.73 50.6 51.6 51.7 I M 34 33. 1 16.84 2.89 50.9 54. 3 54.4 I B 34 34.0 17.09 2.93 50.3 54.1 51.2 I o 34 33.1 16.97 2.91 51.3 52.4 5 2.6 SB I I 27 3 45. 146.4 28.2 12.1 445. 5 56. TEMP I I 27 10.3 0.40 0.08 3.9 1.3 11. 1 I ' s 27 12. 9 0.76 0.15 5.9 2.4 14.2 | M 27 12.9 0.74 0.14 5.7 2.4 14.2 I B 27 12.9 0,76 0. 14 c c —• • > 2.5 11.4 I ' '0 27 12.8 0.75 0. 14 5.9 2.4 11.2 TEMFN I s 27 2.6 0.76 0. 15 28.5 2.6 3.6 I M 27 2.5 0.75 0.14 30.0 2.6 3.6 I B 27 2.5 0.78 0. 15 31.2 2.6 3.6 I o 27 2.5 0.75 0. 14 30.0 2.5 3.5 NQ3 i i 27 19. 1 2.82 0.54 14.8 11.3 2 2.7 N03N I s 27 19. 1 2.81 0.54 14.7 11.3 22.7 I M 27 19. 1 2,82 0.54 14.6 11.3 2 2.7 I B 27 19. 1 2.81 0.54 14.7 11.3 2 2.7 1 o 27 19. 1 2.79 0.54 14.6 11.3 22.7 OXY | I 27 7.39 0.644 0. 124 8.7 3.23 9.S7 1 s 27 12.26 1.022 0. 187 8.3 3,87 14. 13 1 M 27 12.13 1. 121 0.216 9.2 4. 21 13. 56 12 3 I B 27 11.81 1.336 0 . 257 11.3 4 . 9 S 14.30 0 27 11.86 0.S70 0 . 187 8 . 2 3 . 9 3 13.15 OXYN S 27 4. 87 0. 935 0 . 180 19.2 3 . 4 3 6 . 6 7 H 27 a. 74 1 .045 0.201 2 2 . 0 4 . 2 2 6 .7 4 |.: E 27 4 . 4 5 1. 111 0.22G 2 5 . 6 3 . 7 S 6 . 0 2 I o 27 4 . 4 7 0.806 0 . 155 18.0 3 . 0 0 6 . 0 0 SflT i I 27 7 9 . 7 . 1 1.4 9.1 3 6 . 107. s 27 138. 13.0 2 . 5 9 . 4 5 0 . 164. I M 27 137. 13.9 2.7 10.1 5 7 . 16 5 . I 3 27 133. 15.8 3 . 0 11.9 5 5 . . 158. I o 27 134. 12.4 2 . 4 S , 3 5 6 . 165. CHLA i s 27 3 8 . 8 7 . 0 8 1.36 18.2 27.2 5 1 . 7 I M 27 4 0 . 8 7 . 5 7 1.46 18.6 2 5 . 0 5 4 . 4 | B 27 4 1 . 8 7 . 4 6 1.44 17.8 2 6 . 6 5 1 . 2 | 0 27 4 0 . 6 7 , 7 3 1 . 4 9 18.S 3 0 . 4 5 2 . 6 CHLE I s 27 1 .7 1 , 5 0 0.29 8 8 . 2 5 . 9 5 . 9 | CS 27 1.5 1. 11 0.21 74.0 4 . 4 4 . 4 I B 27 1.6 1 .28 0 . 2 5 8 0 . 0 5 . 4 5.4 I- o 27 1 .6 1. 46 0.28 91.3 4 . S 1 . 9 CHIC I s 27 2 0 . 2 3 . 1 9 0 . 6 2 15.8 13.4 2 6 . 5 I H 27 2 0 . 0 3 . 0 2 0 . 5 8 15. 1 11.3 2 4 . 6 I B 27 2 0 . 8 3 . 4 9 0.67 16.8 13.8 2 5 . 9 I o 27 2 0 . 6 3 . 15 0.61 15.1 11.2 2 5 . 6 CT I • s-27 4 3 . 0 7 . 7 0 1.48 17.9 34.4 5 6 . 1 I a 27 4 5 . 2 7 . 8 4 1.51 17.3 3 1 . 3 5 6 . 9 ! B 27 4 5 . 7 6 . 9 4 1.34 15.2 27 .6 5 9 . 5 I o 27 4 6 . 0 7-78 1.50 16.9 3 5 . 6 5 5 . 8 EA | I 1 . 105 |- s 27 . 0 4 7 . 0 4 4 , 0 0 8 9 3 . 6 .179 . 179 I M 27 . 0 3 9 . 0 3 5 . 0 0 7 8 9 . 7 .118 . 148 I B 27 . 0 4 0 . 0 3 3 . 0 0 6 8 2 . 5 .148 . 148 I o 27 .041 . 0 4 3 . 0 0 8 104. , . 1 3 6 . 136 Cfl I I 1 1, 153 I s 27 . 5 2 8 . 0 6 6 . 0 1 3 12. 5 . 2 7 5 . 681 I M 27 . 4 9 7 . 0 6 5 . 012 13. 1 . 2 8 4 . 68 9 I B 27 , 5 0 3 . 0 6 6 . 0 1 3 13. 1 . 2 9 0 . 669 I o 27 . 5 1 9 . 0 7 3 .014 14.1 m 2 8 S . 7 0 7 CTA I I 1 1.123 i s 27 1 , 120 . 168 . 0 3 2 15.0 .706 1,5 44 I H 27 1.118 . 1 6 1 . 0 3 0 14.4 . 6 5 9 1.5 28 i E 27 1. 104 . 133 , 0 2 6 12.0 . 5 6 9 1 .509 1 o 27 1.138 . 1 4 5 . 0 2 8 12,7 . 6 5 1 1. 562 EC 1 I 1 . 0 9 1 I s 27 . 0 8 6 . 0 7 8 . 0 1 5 9 0 . 7 * 3 3 3 ..333 I fi 27 . 0 7 5 . 0 6 3 .012 6 4 . 0 .291 . 2 9 1 1 B 27 .078 . 0 6 5 . 0 1 2 8 3 . 3 . 2 8 5 . 2 8 5 1 o 27 . 0 7 4 . 0 7 0 .014 S4.6 . 2 5 5 . 2 5 5 ECT 1 I 1 . 0 9 3 1 s 27 . 0 4 5 . 0 4 6 . 0 0 8 102. .186 . 1 6 6 | M 27 . 0 3 7 . 036 . 0 0 7 97. 3 .147 . 147 I B 27 . 0 3 7 . 03 2 . 0 0 6 100. . 1 4 0 . 1 4 0 i o 27 . 0 3 6 . 0 3 8 . 0 0 7 106. . 1 3 1 . 13 1 CCT | I 1 1.027 1 s 27 .481 . 0 8 7 .017 18.1 • . 3 9 9 . 7 0 8 1 M 27 . 453 . 0 9 3 .018 2 0 . 5 .437 . 7 39 1 B 27 . 4 5 9 .064 . 0 1 2 13.9 . 2 7 3 . 569 1 o 27 , 4 6 1 . 0 7 6 . 0 1 5 i e . 5 .377 .719 Table 13. R e s u l t s of the a n a l y s i s o f va r i a n c e and m u l t i p l e c l a s s i f i c a t i o n a n a l y s i s f o r s e l e c t e d v a r i a b l e s f o r EXP4A as a f u n c t i o n of the independent f a c t o r s TIME and STATION. F value s and s i g n i f i c a n c e l e v e l s i n the ANOVA are presented f o r the n i t r a t e - d e p l e t e d p e r i o d o n l y , s i n c e the s i g n i f i c a n c e values f o r the t o t a l e x p e r i -ment (t=34) are s i m i l a r . The ten sampling times f o r the p r o d u c t i v i t y v a r i a b l e s i n c l u d e every t h i r d day from Day 6. Data from the bottom s t a t i o n has been excluded (N/I) i n the analyses of the other v a r i a b l e s (TEMP t o CCT)..MULT R i s the m u l t i p l e c o r r e l a t i o n between the dependent v a r i a b l e and both independent v a r i a b l e s TIME and STATION. The MCA t a b l e i n d i c a t e s the e f f e c t of each category of STATION, expressed as a d e v i a t i o n from the grand mean, and shows the time of the minimum and maximum d e v i a t i o n s d u r i n g the n i t r a t e - d e p l e t e d p e r i o d . A N A L Y S I S O P V A R I A N C E M U L T I P L E C L A S S I F I C A T I O N A N A L Y S I S V AR 1 BY T I M E | B Y S T A T I O N | MULT J GRAND | DEV'N BY S T A T I O N | D E V N BY T I M E NAME ] T F S I G . ] A F S I G . I . S ] MEAN ] S U R MID BOT OUT | M I N . DAY ] MAX. DAY T E M P J 2 9 *** . 0 0 0 | 3 8. 5 - 0 0 1 . 9 9 8 ] 1 4 . 6 J . 0 5 - . 0 6 N / I -0 1 | - 2 . 0 3 2 4 I 1 - 8 4 3 4 T E M P N J 29 *** . 0 0 0 J 3 8 . 5 . 0 0 1 | . 9 9 8 | 4-3 j . 0 5 - . 0 6 N / I - 0 1 ; | - 2 . 2 7 3 1 | 1 - 8 3 1 9 , 2 0 OXY J 2 9 1 6 . . 0 0 0 | 3 1.9 . 16 % \ . 9 4 2 I 1 1 . 1 8 ] - 0 2 . 12 N / I 1 3 j | - 1 . 4 9 3 0 , 3 1 J 2- 1 7 1 9 O X Y N i 2 9 2 7 . . 0 0 0 J 3 1. 9 . 1 6 1 I - 9 6 5 I 3 . 7 1 | - 0 2 - 1 2 N / I - - 1 3 - 3 . 4 5 1 3 1 2 . 7 6 2 0 SAT | 2 9 2 2 - . 0 0 0 | 3 1.7 . 1 8 5 j . 9 5 7 I 1 3 0 . 1 - 3 1.2 N / I - 1 - 5 \ - 2 2 . 6 3 0 ] 2 9 . 6 1 9 C H L A | 2 9 1 6 . . 0 0 0 j 3 2.4 . 0 9 6 j . 9 4 2 1 1 7 - 6 ] - . 3 8 - . 3 8 N / I . 7 6 - 8 . 8 7 1 3 ] 9 . 7 0 2 4 C H L B | 2 9 1 4 . - 0 0 0 ] 3 0. 6 - 5 6 7 | - 9 3 7 | 1.4 | . 0 5 - . 0 4 N / I . 0 0 - 1 . 2 3 2 0 ] 1 . 4 1 6 C H L C | 2 9 1 8 . - 0 0 0 | 3 0. 8 - 4 4 7 j . 9 4 9 ] 1 1 . 0 ] . 0 6 - . 2 3 N / I - 1 6 \ - 4 . 3 9 1 4 1 6 . 8 7 6 C T | 2 9 8. 1 . 0 0 0 ] 3 1. 8 . 1 7 8 | . 8 9 7 | 2 2 . 2 1 - 0 . 4 - 0 - 6 N / I 1.0 j - 1 0 . 9 2 8 J 9-1 7 BA | 2 9 1 6 . - 0 0 0 ] 3 2. 2 . 1 1 9 . 9 4 2 ] . 0 9 1 . 0 1 . 0 0 N / I - . 0 1 - 0 . 0 8 2 0 , 2 5 ] . 1 0 3 4 CA J 2 9 3-3 . 0 0 0 I 3 1.5 - 2 2 4 j - 7 9 3 1 . 6 4 ] . 0 2 . 0 0 N / I -.0 2 | - 0 . 1 3 2 5 I - 1 9 2 8 C T A J 2 9 1 2 . - 0 0 0 J 3 0, 1 - 9 2 9 j - 9 2 8 ] 1 . 2 8 ] - 0 0 . 0 0 N / I - 0 0 | - 0 - 2 5 2 9 | . 3 1 1 9 BC J 2 9 1 6 - . 0 0 0 i 3 0. 8 . 4 7 9 j . 9 4 4 | 0. 1 3 ] . 0 0 . 0 0 N / I . 0 0 - 0 . 11 2 0 , 2 5 ] . 1 2 3 4 BCT \ 2 9 1 7 . - 0 0 0 J 3 2 - 2 - 1 1 5 | . 9 4 7 ] 0 . 0 7 ] . 0 0 . 0 0 N / I . 0 0 - 0 . 0 6 2 0 , 2 5 | . 0 6 2 8 , 3 4 C C T | 2 9 3 . 6 . 0 0 0 ] 3 0.9 . 4 0 9 | . 8 0 3 | 0 . 5 1 ] . 0 2 . 0 0 N / I - . 0 1 | - 0 . 16 2 0 i - 1 5 9 PGO | 1 0 2 . 8 - 0 3 0 ] 3 1. 4 . 2 7 4 \ - 7 8 0 | 2 2 0 . I " 1 1 . - 1 8 . 2 9 . N/A - 1 1 5 . 3 0 ] 8 6 . 6 , 2 1 PNO | 10 2 - 7 - 0 3 6 | 3 1.3 - 2 8 7 | - 7 7 3 | 1 8 1 . | - 1 2 . - 1 7 . 2 9 N/A j - 9 3- 3 0 ] 1 0 2 . 6 R E S J 1 0 5 .6 . 0 0 1 ] 3 0. 0 . 9 8 4 j . 8 5 9 I 4 0 - I 1- 0- - 1 - N/A ! - 2 2 . 3 0 | 6 5 . 1 2 PBOD J 10 2. 1 - 0 9 2 J 3 5. 4 . 0 1 4 j - 7 8 7 ] 3 8 . 1 - 6 - - 5 . 1 1- N/A j - 1 4 - 9 I 2 0 . 2 7 PGODY \ 1 0 3 .6 . 0 1 1 | 3 1- 2 . 3 3 8 . 8 1 0 3 2. 11 J . - - 0 9 -- 16 . 2 5 N/A - 1 - 0 1 3 0 ] 1 . 1 1 6 P C D Y J 10 2.2 - 0 7 9 ] 3 5- 1 . 0 1 8 i . 7 8 8 \ 0 . 3 5 J - . 0 5 - - 0 4 1 . 0 0 N/A ] - 0 . 15 9 ] 0 . 1 6 6 PGOST J 1 0 5.0 . 0 0 2 j 3 2. 1 . 1 5 3 I - 8 5 6 I 1 1 - 6 ] 0 . 9 0- 1 - 1 - 1 N/A | - 4.3 3 0 | 4.3 1 2 PNOST | 10 2. 7 . 0 3 4 ] 3 0 . 5 . 6 0 0 j - 7 6 6 ] 9.2 ] 0.6 0-0 - 0 . 6 N/A i - 3. 3 3 0 I 4. 1 2 1 R E S S T I 10 5-0 . 0 0 2 | 3 0. 9 . 4 3 5 | - 8 5 0 ] 2.4 | 0-4 0. 1 - 0 . 5 N/A ; - 1 . 3 2 4 | 5- 4 12 A S S J 1 0 4.0 . 0 0 6 ] 3 0. 6 . 5 8 8 | - 8 2 1 ] 2.0 J - 0 . 1 - 0 . 1 0. 1 N/A | - 0.6 2 4 | 1. 0 3 4 E X C S T ] 5 6-8 . 0 1 1 ] 3 7 . 3 . 0 1 5 ] - 9 1 6 1 6-5 j 0.4 1.5 - 2 . 0 N/A | - 3. 6 3 0 1 1.7 5 A L P H A G ] 10 1 3 . . 0 0 0 3 3 5.6 . 0 1 3 J - 9 3 5 I 6 3 - 2 1-10.0 - 1 . 6 1 1 . 6 N/A • - 2 3 . 6 1 5 , 1 8 ] 4 8 . 1 2 1 A L P H A C ] 10 2 4 . . 0 0 0 . 3 1 6 . . 0 0 0 | . 9 6 6 \ 11.6 ] - 2 . 8 - 0 . 7 3.5 N/A | - 7 . 0 1 2 ] 1 7 . 5 3 0 Table 14. R e s u l t s of the a n a l y s i s of v a r i a n c e and m u l t i p l e c l a s s i f i c a t i o n a n a l y s i s f o r s e l e c t e d v a r i a b l e s f o r EXP4B as a f u n c t i o n of the independent f a c t o r s TIME and STATION. F values and s i g n i f i c a n c e l e v e l s i n the AN0VA are presented f o r the n i t r a t e - d e p l e t e d p e r i o d o n l y , s i n c e the s i g n i f i c a n c e v a l u e s f o r the t o t a l e x p e r i -ment (t=34) are s i m i l a r . The ten sampling times f o r the p r o d u c t i v i t y v a r i a b l e s i n c l u d e every t h i r d day from Day 6. Data from the bottom s t a t i o n has been excluded (N/I) i n the a n a l y s e s of the other v a r i a b l e s (TEMP to CCT) . MULT R i s the m u l t i p l e c o r r e l a t i o a between the dependent v a r i a b l e and both iadependent v a r i a b l e s TIME and STATION. The MCA t a b l e i n d i c a t e s the e f f e c t o f each category of STATION expressed as a d e v i a t i o n from the grand mean, and shows the time of the minimum and maximum d e v i a t i o n s d u r i n g the n i t r a t e - d e p l e t e d p e r i o d . VAB | NAME | ANALYSIS BY TIME T F SIG. OF VARIANCE \ BY STATION J J A F SIG- j MULT 1 GRAND J MEAN MULTIPLE CLASSIFICATION J DEV«N BY STATION J DEV J SUB MID BOT OUT J MIN. ANALYSIS •N BY TIME DAY J MAX. DAY TEMP 1 27 *** -000 1 4 3.2 -028 . 998 J 12-9 | - 02 .01 -.01 -.02 | -1.07 24 | 1-33 13,34 TEMPN | 27 *** -000 1 4 3-2 .029 | . 998 j 2-5 1 .02 .01 -.01 -.02 | -1. 54 31 1 1.04 20 N03N 1 27 *** . 000 1 4 0- 5 -677 J .999 1 19.1 J .00 -03 -.01 -.02 \ -7. 67 8 | 3.53 27 OXY J 27 29. . 000 j 4 7. 2 -000 | .953 | 12.02 i 0.23 - 11 -.18 -.16 j -2.25 23 | 1.91 12 OXYN | 27 22. -000 1 4 7-2 -000 i .940 i 4.63 J 0.23 - 11 -. 18 -. 16 J -1.68 23 | 1.71 33,34 SAT 1 27 37. .000 1 4 8.3 -00 0 j -962 J 135. 1 2-8 1.3 -2.3 -1.8 i -26. 9 23 | 27.7 13 CHLA J 27 18. .000 1 4 4- 1 -00 9 ! . 926 1 40.6 ] -1.8 0-2 1-3 0.3 | -12. 7 9 | 11-6 15 CHLB I 27 20. - 000 1 4 0.9 .442 | .933 j 1-6 I . 13 -- 11 .03 -.04 | -1.60 20,21 I 3-54 8 CHLC J 27 24. .000 1 4 3.3 .026 j -944 i 20.5 | --24 -.48 .37 .36 j -7. 23 19 | 4.31 24 CT J 27 *** -000 1 4 2.7 .052 | - 876 1 45.0 1 -2.0 0-2 0.7 •1.0 | -20. 2 9 1 9-6 15 BA j 27 20. .00 0 1 4 1-4 -264 .933 1 .04 % .01 -00 .00 .00 | - .04 19-21 1 -11 8 CA ] 27 5.6 .000 1 4 2.7 .053 | -815 | -51 | -02 -.01 -.01 .01 - .09 19,22 1 .09 29,33 CTA i 27 26. .000 1 4 1.6 .209 i -947 | 1- 12 ) .00 .00 -.02 .02 | - .23 9 1 .34 26 BC J 27 29. .000 1 4 1. 4 . 25 2 | -953 1 - 0 8 3 -01 -00 . 00 .00 | - .08 20,21 1 .21 8 BCT | 27 31. .000 1 4 2. 4 -071 | .956 j .04 1 -01 -00 .00 .00 J - . 04 19-21 1 - 1 1 8 CCT | 27 9.3 -000 i 4 1.8 - 160 j -870 3 .46 | -02 -.01 -00 -00. , - . 14 19 | .18 9 PGO J 10 25- . 000 1 3 2.6 .103 ] -96 3 i 341. 1 20- -13. - 7. N/A -249. 6 I 108. 12 PNO | 10 18. .000 I 3 3.0 -076 -951 i 294. | 23- -13. -10. N/A -231- 6 1 79. 12 RES J 10 1.8 - 150 1 3 .23 -786 | - 688 1 47. 1 ~ 3. - 0. - 4. N/A - 24. 9 1 29. 12 PROD j 10 1. 7 . 163 I 3 .92 .318 J .697 J 51. J 3- - 4. 2. N/A : - 16. 6 1 18- 34 PGODY J 10 21. .000 ] 3 2. 4 -117 | .957 j 3.17 1 19. -13. -06. N/A -2. 26 6 | 1.04 12 PCDY \ 10 1. 4 - 247 1 3 0-9 -428 . 670 | 0.46 J 25- -37. - 12 N/A - . 13 6 I -13 34 PGOST | 10 9-8 -000 1 3 3.8 -022 | .919 1 9.5 | 1.0 -0.4 -0. 6 N/A - 3.0 30 i 4. 6 6 PNOST 1 10 5. 1 . 002 1 3 5- 8 .011 ] . 873 | 8.0 1 1- 1 -0.5 -0.6 N/A - 2. 8 30 | 2. 1 18 RESST | 10 7.7 .000 1 3 0.3 -735 1 -892 | 1.5 | -0. 1 0. 1 0.0 N/A - 0.8 24 1 3. 0 6 ASS | 10 38. .000 1 3 1-9 - 176 | -980 1 1-7 \ 0- 1 -0. 1 0-0 N/A | - 0.7 21 J 3. 7 6 EXCST | 5 9.9 -003 1 3 2.6 . 134 -921 | 6.0 ] 0.8 -0.2 -0.6 N/A - 2. 8 30 1 1.8 18 ALPHAG| 10 4.6 -003 1 3 10. .00 1 . 880 1 65.4 1-21- 4 -9.5- 30-9 N/A -29.2 6 3 78.8 30 ALPHACJ 10 9.8 .000 1 3 18. .000 i | .934 ] 10.4 1- 3-2 -1-5 4.4 N/A - 6.4 18 I 10.5 30 128 Table 15. P r o d u c t i v i t y component a n a l y s i s f o r EXE4. RPGC,APGC and EPGO r e p r e s e n t the p r o p o r t i o n of gross p r o d u c t i v i t y due to r e s p i r a t i o n , a s s i m i l a t i o n and exudation. , ESTPGO i s the estimated gross p r o d u c t i v i t y based on the model: ESTPGO=EPGO * APGC -*• EPGG . See t i e t e x t f o r an e x p l a n a t i o n cf the r e s u l t s . EXP4 - TASK a ANALYSIS V AR IG1AND | KDLT ! MISN ] R j , RPGO | 0.21 | .805 APGO J 0.18 | .857 EPGO | 0,59 | .551 ESTPGO | 0.9 8 | .697 BY STN A SIG EY T CF VAEIANCE TIME I TOTAL SIG 1 K SIG J .055 I 15 .1 19 .029 ] 15 .one I I RPGO | 0.20 j .745 APGO | 0.19 | .816 3 .9 88 3 .271 3 ,002 3 .231 3 .946 3 .039 5-5 10 10 15 15 .0 01 .372 .002 i .461 | 1 .048 I 30 .081 .001 \ 30 .001 EXP4 - TASK E ANALYSIS OF VARIANCE V AR | GRANT; I MOLT BY STN 1 BY TI ME | TOTAL | MEAN I R A SIG I T SIG j K SIG RPGO | 0.18 1 1 .844 ! 3 .387 1 5 .035 j 15 .061 APGO \ 0. 19 1 ,953 3 .893 1 5 .000 | 15 .o e 1 EPGO | 0. €3 1 .768 3 .526 1 5 .122 15 .193 ESTPGO | 0.99 i n .762 ' 3- .872 1 c .108 i 15 .2C1 EPGO j 0.15 i \ .807 3 .434 110 .011 30 .016 APGO 1 0. 17 I .921 j 3 .581 I 10 .000 : 30 .0 00 129 Table 16, Experimental design f o r the i n v e s t i g a t i o n of twc-stage c o n t i n u o u s c u l t u r e s of p l a n k t o n i c h e r b i v o r o u s food c h a i n s , with v a r i a b l e f l u s h i n g r a t e s i n both the primary production tank experiments (FXP5A,EXP5B) and the secondary production tacks (EXP 1 tc EXE4), R e s u l t s f o r the secondary production systems are discus s e d i n Chapter 7,, EXP5A EXP5B TIME FESI00 F, £. F, B, (Days) (/day) (/day) FBIMABY t=1, 14 0.2 5 1.00 PEOCDCTION t=15,28 0.50 1.00 SYSTEMS t=29,4 1 0.10 1.00 t=42,49 N/A 0.50 EXP TIME PEBIOD F.R. . SOURCE OF PBIBABY (days) (/day) INFLOW COMBO NITY I t=18,25 1.00 Tank B Diatoms SFCONCABY (F. E. = 1. 0) EECEUCT1CN I I t=26,33 2,00 Task E Diatoms SYSTEMS (F.B. = 1.0) I I I t=35,4 2 1.00 Tank A F l a g e l l a t e (I»B.=0„1) t=43,50 2.00 Tank E Mixed (F.B. = 0.5) 130 T a i l s 17. R e s u l t s of the n u t r i e n t enrichment experiments at low (0.13 ly/min) and high (0.40 ly/min) i n t e n s i t i e s of p h o t o s y n t h e t i c a l l y a v a i l a b l e r a d i a t i o n during 1XP5. The p r o d u c t i v i t y was measured by the uptake of r a d i o a c t i v e carbon (ug C / l / h r ) . The * V i t a o i n mix' and * Vitamin B12* a d d i t i o n s were made at the same c o n c e n t r a t i o n (*) or at 10x the c o n c e n t r a t i o n (**) as i n the •! Medium' a d d i t i o n . EXPEBIMINT 1 (low PfiB) EX IIBIMENT 2 (high PSE) Enrichment P r o d u c t i v i t y Enrichment P r o d u c t i v i t y C o n t r o l 101. C e n t r e ! 10 4. E Medium (10.0 mi) (1.0 wl) 117. 110, F Medium (10.0 ml) 114, (1.0 ml) 106. Vitamin Mix (+*) 9 3 . Vitamin Mix (**) 103. (*) 83. Vitamin E-12 (**) 112. V i t a n i n B12 <**) 136. (*) 123, T a b l e 18. D e s c r i p t i v e s t a t i s t i c s f o r s e l e c t e d v a r i a b l e s f o r EXP5A, i n c l u d i n g a breakdown i n t o the three p e r i o d s o f v a r i a b l e f l u s h i n g r a t e s : F.R.=.25/day f o r t=1,14; F.R.=.50/day f o r t=15,28; and F.R.=.10/day f o r t=29,41. N r e p r e s e n t s the t o t a l number o f data p o i n t s , i n c o r p o r a t i n g both the f a c t o r s TIME and STATION. TOTAL EXPERIMENT F-R-=- 25/DAY F.R-=-50/DAY F.R.=. 10/DAY V AR SR SAL TEMP | TEMPN 8 N03 J N03N TN03M | OXY 3 OXYN TOXIN 3 SAT CHLA CHLB CHLC CT BA CA CTA BC BCT CCT STN | N MEAN S.D. RANGE MAX 3 N MEAN S. D. j N MEAN S.D. I N MEAN S. D. i - s 41 404. 105. 6 371. 519- 1 14 495. 14.9 14 33 7- .13.1.7 | 13 378. 49.0 3 - 1 41 27. 2 0.92 3. 1 28.9 1 I 1 j 41 11. 8 1.08 4.2 14. 3 1 14 12- 0 0.76 | 14 12- 2 1.49 J 13 11. 1 0-34 2-5 3 164 18. 1 2.3 8 8.5 21-9 3 56 18. 7 2.16 | 56 16.0 1.39 j 52 19.8 1.61 2-5 I 164 6.4 2-4 5 5.7 8.4 i 56 6.7 1.55 56 3. 8 1.26 i 52 8.8 1.38 1 ' i 41 16-7 5-97 22.0 25- 1 3 14 14.3 2.91 J 14 14. 1 7.70 J 13 21.9 1-24 2-5 3 164 1.7 5.54 21.7 21.7 1 56 5.0 8.60 J 56 0.0 0-08 3 52 0.0 0. 13 2-5 | 164 14. 9 7-68 28.5 25. 1 3 56 9.3 6. 19 | 56 14. 1 7-4 8 J 52 21.9 1-20 2-5 | 164 17.3 7.07 27. 1 2 7. 1 1 56 12.0 6. 12 J 56 16. 3 5.72 1 52 24. 1 1.98 1 1 41 7. 24 ... 787 2. 88 8. 89 1 14 7. 65 -473 14 7-46 - 973 1 13 6. 55 . 160 2-5 J 164 9.93 1.629 6.84 13. 83 1 56 9.40 1-822 | 56 10.64 .813 3 52 9.73 1. 812 2-5 1 164 2-69 1.83 4 7.74 7.05 J 56 1. 74 1.658 i 56 3- 18 1- 53 4 3 52 3. 18 1. 896 2-5 J 164 2-95 1.849 7.61 7.05 I 56 1. 98 1.794 j 56 3.71 1- 405 J 52 3. 18 1. 896 1 3 41 80. 10- 0 38. 102. 1 14 84. 6. 1 ] 14 83- 12.7 J 13 71. 2.0 2-5 1 164 124. 19-3 85- 177. i 56 119. 24.5 1 56 127. 8.4 j 52 125. 2 0.4 2-5 1 164 17.7 12-95 54-0 54. 1 1 56 9.7 10-67 ] 56 26.6 12.34 J 52 16.8 9.52 2-5 J 164 0. 5 0-81 3.6 3.6 1 56 0. 9 1. 10 56 0.3 0.63 J 52 0.3 0. 37 2-5 J 164 9.6 6-96 39-6 39.6 3 56 4. 4 4-50 | 56 14. 5 7.01 j 52 10.0 4.87 2-5 1 164 26- 0 16.32 65.8 66.0 1 56 12- 6 11-45 J 56 34-0 13.72 J 52 3 1.8 14. 31 2-5 J 164 0. 003 0. 157 0 . 833 0. 833 I 56 0 .143 0.172 | 56 0.017 0.031 | 52 0- 090 0. 192 2-5 | 164 0. 632 0.389 2 -667 2.667 3 56 0 .586 0.424 j 56 0. 549 0-08 1 ] 52 0- 772 0.503 2-5 3 164 1. 779 0.996 6 . 829 7.800 1 56 1 .558 0. 464 ! 56 1-322 0.159 | 52 2. 511 1. 4 43 2-5 3 164 0. 100 0. 148 1 .000 1.000 56 0 -201 0.189 | 56 0.029 0-051 J 52 0. 068 0- 103 2-5 3 164 0.040 0.059 0 -294 0.294 3 56 0 .085 0-075 J 56 0.012 0-020 J 52 0.021 0.033 2-5 | 164 0.368 0. 123 0 -714 0.714 J 56 0.370 0-179 I 56 0-419 0-066 j 52 0.310 0.054 T a b l e 19- D e s c r i p t i v e s t a t i s t i c s f o r s e l e c t e d v a r i a b l e s f o r EXP5B, i n c l u d i n g a breakdown i n t o the two p e r i o d s of v a r i a b l e f l u s h i n g r a t e s : F-E-=1.00/day f o r t=1,41 and F.R-=-50/day f o r t=42,49. Note that the f i r s t p e r i o d (F. R«=1. 00/day) corresponds t o the t o t a l e x p e r i m e n t a l p e r i o d f o r EXP5A. N rep r e s e n t s the t o t a l number of dat a p o i n t s , i n c o r p o r a t i n g both the f a c t o r s TIME and STATION. F-R. = 1.00 PEE DAI F.E-=0-50 PEB DAY VAR 1 STN ] N MEAN S. D. RANGE MAX 1 N MEAN S.D. RANGE MAX SR J 1 1 j 41 404. 105-6 371. 519. I 8 298. 89.0 259. 380-SAL i 1 1 41 27-2 0.92 3- 1 28.9 i 8 TEMP i 1- ] 41 11.9 1-10 4.2 14. 3 1 8 10.6 0. 46 1.4 11.5 i 2-5 | 164 15.0 .925 3.8 16. 5 a 32 15.0 0.57 1.8 16. 0 TEMPN i 2-5 J 164 3-1 0.87 4 - 3 4. 9 i 32 4. 4 0.83 2.5 5.6 N03 i 1 | 41 16.4 6. 18 2 2. 4 24.9 i 8 22.9 1.86 5-0 2 5.4 i 2-5 | 164 2.8 6.48 21-9 21.9 32 0.0 0.0 0.0 0.0 N03N i 2-5 | 164 13.5 8.92 29.8 24. 9 i 32 22. 9 1.76 5.0 25.4 TN03N i 2-5 j 164 15. 9 8-06 27. 1 27. 2 \ 32 23.4 1.89 5.6 26.6 OXY i 41 7.29 .884 3.08 8.96 1 8 6. 14 0.387 1-00 6.76 i 2-5 i 164 10-92 1.612 6-44 14. 12 1 32 11.05 0.981 4-44 12.61 OXYN 1 2-5 ] 164 3.62 1-999 8.08 7.89 1 32 4-90 0- 908 3. 86 6.27 TOXYN 2-5 J 164 3.87 1.882 7-49 7.89 I 32 4-90 0.908 3. 86 6.27 SAT 1 1 J 41 80- 11. 1 38. 101. I 8 66. 4.62 12. 74. 1 2-5 | 164 128. 19. 4 74. 88. 1 32 130- 1 1.6 51. 148. CHLA 1 a 2-5 1 164 25-8 15.78 61.4 61-5 J 32 32.7 3-96 15.9 41.0 CH LB 2-5 1 164 0.6 0.88 3.3 3-3 1 32 0.7 1-52 7.0 7.0 CHLC 5 2-5 | 164 15-0 9.76 39. 1 39- 1 1 32 20. 1 2- 95 14.5 30. 3 CT i 2-5 | 164 30.0 17.67 6 9.3 69.5 ] 32 38.3 5. 14 22. 5 48.0 BA i 2-5 J 164 0. 081 0- 172 0.9 43 0.943 1 32 0-023 0- 049 0 -227 0.227 CA ? 2-5 | 164 0. 659 0.392 2- 285 2-28 5 9 32 0-616 0. 084 0 -418 0. 959 CTA i i 2-5 J 164 1.275 0.396 2-359 3.20 1 8 32 1.169 0. 073 0 .341 1.338 BC 2-5 | 164 0.093 0- 133 0-545 0.545 1 32 0.036 0. 077 0 .370 0- 370 BCT i 2-5 \ 164 0. 049 0.075 0-318 0.318 1 32 0-020 0. 041 0 .189 0-189 CCT i 2-5 ] 164 0.500 0. 156 1.013 1-Q13 1 32 0.528 0.076 0 .379 0-828 T a b l e 20. R e s u l t s of t h e a n a l y s i s of va r i a n c e and m u l t i p l e c l a s s i f i c a t i o n a n a l y s i s f o r s e l e c t e d v a r i a b l e s as a f u n c t i o n of the independent f a c t o r s TIME and STN f o r EXP5A. S t a t i s t i c s are based on data from the n i t r a t e - d e p l e t e d p e r i o d (T>4). *** i n d i c a t e s F-values g r e a t e r than 99. The eleven 'TIMES• f o r the p r o d u c t i v i t y v a r i a b l e s i n c l u d e every t h i r d day from Day 6, except Day 15 when the data was mis s i n g . The MCA i n d i c a t e s the e f f e c t of each category of STATION, expressed as a d e v i a t i o n from the grand mean, and shows the maximum and minimum d e v i a t i o n s d u r i n g the n i t r a t e - d e p l e t e d p e r i o d . MULT R i s the m u l t i p l e c o r r e l a t i o n between the dependent v a r i a b l e and both independent v a r i a b l e s TIME and STN. S i g n i f i c a n c e v a l u e s i n the A NOVA are based on t-1 df f o r TIME and a-1 df f o r STATION. ANALYSIS OF VARIANCE MULTIPLE CLASSIFICATION ANALYSIS VAfi J BY TIME J BY STATION | MULT | GRAND | DEV* N BY STATION | DEV • N BY TIME NAME ] T F SIG. 1 A F SIG. 1 H J MEAN SUR MID BOT OUT j MIN. DAY J MAX. DAY TEMP J 37 *** -000 ] 4 41. .000 i .994 1 18. 4 j 0. 15 0.09 -.45 0.20 -4- 5 27 | 2.9 37 TEMPN ] 37 *** -000 ! ^  41. .000 | .995 J 6.6 | 0. 15 0. 10 -.45 0.20 -5. 1 20 J 3.6 36 N03 1 37 2.5 .06 1 i 4 1.0 . 482 J .536 1 0.0 3 -.01 -.01 .03 -.01 j 0-0 MANY J 0.2 33 N03N 1 37 *** -000 | 4 2. 8 .042 J1.000 I 16.5 1 0.01 0.01 -.03 0.0 1 - -13. 4 20 J 8.6 27 TN03N 1 37 *** .000 1 4 2-7 .051 3 1.000 I 18.8 j 0.01 0.01 -.04 0.01 -9- 2 20 | 8-4 34 OXY i 37 *** .000 1 4 12. .000 3-991 3 10.05 j 0- 13 0-04 -.21 0.04 | -3.02 41 1 3.58 5 OXYN J 37 *** .000 1 4 12. .000 J -993 J 2.83 j 0. 13 0-04 -.21 0.04 -3.35 10 | 3.91 29 TOXYN | 37 *** .000 1 4 12. .000 j .993 3 3.09 ] 0-13 0. 04 -.21 0.04 -3.47 10 3 3- 65 29 SAT 1 37 *** .000 1 4 18. .000 J .987 3 126. 1 2.0 0.8 -3.6 0.9 , -34. 41 j 48. 5 CHLA 1 37 *** .000 1 4 4.9 -003 I .99 1 3 18.8 1 -0.6 -0.5 -1.0 0. 1 , -18.0 41 | 26.8 26 CHLB 1 37 7-3 .000 ! 4 1- 2 .31 1 1 -851 3 0.4 j 0.0 0.0 0.1 -0. 1 | -0. 4 23-31 3 3-0 5 CHLC i 37 43. .000 ! 4 3.2 .025 i -969 3 10.2 1 -0.3 -0.2 0.9 -0.4 | -9.5 11 J 16-6 26 CT | 37 90- .000 i 4 2.3 .078 i -985 1 27.9 1 -0,6 -0.8 0-5 0-9 -23. 5 41 | 28.7 26 BA j 37 8.6 .000 ] 4 .79 -500 | .862 3 0.07 0.01 0.01 0.00 -.02 \ -0.07 MANY J 0.55 41 CA J 37 6- 1 .000 t 4 1. 5 -213 j . 829 3 0.61 3 0. 04 0.02 0-02 -.07 J -0. 47 1 1 3 1.58 41 CTA 1 37 26. .000 i 4 .62 .606 3 -951 J 1.81 j 0.01 0.05 -. 06 0.00 j -0. 68 5 | 4.30 41 BC 1 37 5.2 -000 1 4 .42 -737 ] .798 3 0.08 I -.01 0.01 0-00 0.00 | -0. 08 23-31 1 0. 41 8 BCT 1 37 6.3 .000 I 4 .36 .782 3 -824 1 0.03 j 0.00 0.00 0.00 0.00 | -0.03 23-31 3 0. 11 9 CCT | 37 4.0 -000 1 4 3.0 .033 3 -769 J 0-35 3 0.01 0.00 0.03 -.0 3 J -0. 26 11 | 0. 14 24 PGO J 11 18. .000 1 3 1.3 -284 J -949 3 160- 1 4. 9. -13. N/A j -104. 9 | 109. 21 PNO | 11 18. .000 1 3 0.7 -523 1 .948 3 119. -3. 9. -6. N/A ; -107. 9 J 125. 21 EES \ 11 1.7 . 153 1 3 1.4 .26 7 3 -705 | 41. j 6.6 0.2 -6.8 N/A ; -20. 9 39 | 21-4 27 PROD 1 11 34. -000 1 3 1.7 .208 1 - 972 | 61. -2. 4 4.2 -1.7 N/A | -46.9 9 J 50- 1 24 PGODY | 11 14. . 000 i 3 1.4 -261 3 - 938 | 1.39 j .04 .08 -. 12 N/A ! -- 89 9,39 3 1- 03 21 PCDY I 11 26. .000 \ 3 1.8 . 197 | . 983 | 0.50 1 -.25 .34 -.09 N/A : 38 9 3 .36 6 PGOST | 11 3-4 .010 1 3 1. 1 -35 3 J .80 1 I 10 -6 3 2- 1 -0.4 -1.8 N/A -6. 0 18 a 1 7 . 4 9 PNOST | 11 12. .000 1 3 1-4 . 267 | .929 J 6.5 j -0. 1 0 . 6 -0.5 N/A J -3.6 18 1 7.2 21 RESST | 11 4.3 .003 1 3 1- 4 .259 J .834 J 4. 1 2.2 -0. 9 -1.2 N/A i -2. 8 24 | 18.5 9 ASS 1 11 3.7 .006 I 3 0. 5 .626 3-811 1 3.8 0- 3 0.0 -0.3 N/A j -2. 1 18 ] 3.0 9 EXCST | 5 8.3 .006 1 3 1. 8 . 234 J - 906 1 2.2 j -0-2 0.3 -0. 1 N/A J -0.7 18 1 1-3 12 ALPHAG| 11 2-4 .043 | 3 0.2 .813 | .744 3 39.8 3 -1.6 -1.3 2-9 N/A : -17. 9 36 3 29-2 6 ALPHACJ 11 2. 6 -032 1 3 3. 1 .068 1 .786 3 14.0 J -2. 5 -0.2 2-7 N/A -6.4 27 J 8.9 24 EPGO | 11 7-1 .000 ] 3 1.9 . 170 1 .888 1 0.32 i 0. 06 -.03 -.03 N/A i -.22 21 3 0.47 9 APGO | 11 3-2 .012 1 3 1-5 .23 8 1 .799 ] 0.40 i -.04 -.02 .05 N/A , -. 18 21 J .29 6 T a b l e 21. R e s u l t s of the a n a l y s i s of varia n c e and m u l t i p l e c l a s s i f i c a t i o n a n a l y s i s f o r s e l e c t e d v a r i a b l e s as a f u n c t i o n of the independent f a c t o r s TIME and STN f o r EXP5B. S t a t i s t i c s a r e based on data from the n i t r a t e - d e p l e t e d p e r i o d (T>6). F-values g r e a t e r than 99. are denoted by The eleven •TIMES' f o r the p r o d u c t i v i t y v a r i a b l e s i n c l u d e e v e r y t h i r d day from Day 6, except Day 15 when the data was mis s i n g . The MCA i n d i c a t e s t h e e f f e c t o f each category of STATION, expressed as a d e v i a t i o n from the grand mean, and shows the maximum and minimum d e v i a t i o n s d u r i n g the n i t r a t e - d e p l e t e d p e r i o d . MOLT R i s the m u l t i p l e c o r r e l a t i o n between the dependent v a r i a b l e and both independent v a r i a b l e s TIME and STN. S i g n i f i c a n c e v a l u e s i n the ANOVA are based on t-1 df f o r TIME and a-1 df f o r STATION. A N A L Y S I S OF V A R I A N C E M U L T I P L E C L A S S I F I C A T I O N A N A L Y S I S VAR J BY T I M E | BY S T A T I O N MOLT j GRAND | DEV•N BY S T A T I O N I D E V N B Y T I M E NAME ] T F S I G . 1 A 7 S I G . ,| H | MEAN J S U R M I D BOT OUT I M I N . DAY | MAX. DAY T E M P ] 3 5 *** . 0 0 0 4 2 5 . . 0 0 0 - 9 8 6 1 1 5 . 1 J 0. 1 2 - . 0 2 - . 2 1 0 - 1 0 j - 2 . 1 2 6 1 1. 3 9 T E M P N | 3 5 *** . 0 0 0 4 2 5 - - 0 0 0 ; . 9 8 6 I 3.2 | 0 . 1 2 - . 0 2 - . 2 1 0- 1 0 ! - 2 . 6 2 0 J 1.4 41 N 0 3 ] 3 5 3 7 . . 0 0 0 4 1. 7 . 1 6 8 . 9 6 2 | 0.3 1 0.0 0.0 0- 1 0.0 | - 0 . 3 MANY | 4.0 1 3 N 0 3 N J 3 5 *** . 0 0 0 4 1.7 - 1 6 3 ] . 9 9 9 | 1 6 . 2 | 0-0 0.0 - 0 . 1 0.0 i - 1 3 . 7 2 0 1 8 . 5 2 7 T N 0 3 N I 3 5 *** - 0 0 0 4 1. 7 . 1 6 4 j . 9 9 9 j 1 8 . 3 J 0.0 0.0 - 0 . 1 0-0 | - 9 . 3 2 0 1 8.9 3 4 OXY J 3 5 1 6 . . 0 0 0 4 1 1 . - 0 0 0 . 9 2 1 111-38 1 0 . 2 4 0 . 2 1 -. 44 - . 0 1 | - 2 . 8 0 1 2 | 1 . 9 5 3 2 OXYN | 3 5 3 0 . - 0 0 0 4 1 1 . . 0 0 0 | . 9 5 5 | 4 . 1 7 1 0 . 2 4 0. 2 1 -. 44 - . 0 1 | - 2 . 8 4 2 0 | 2 . 9 6 3 2 T O X Y N J 3 5 *** . 0 0 0 | 4 1 1 . - 0 0 0 | . 9 4 7 J 4 . 4 1 1 0.24 0 - 2 1 -. 44 - . 0 1 - 2 . 9 2 1 2 J 2 . 7 2 3 2 S A T J 3 5 1 5 - . 0 0 0 1 4 1 2 . - 0 0 0 . 9 2 0 I 1 3 4 . ] 3.2 2.4 - 5 . 7 0.2 | - 3 2 . 1 2 1 2 5 . 8 C H L A | 3 5 5 0 . . 0 0 0 ) 4 3 . 7 . 0 1 5 j . 9 7 1 | 2 9 . 6 I - 0 . 6 - 0 . 4 1.8 - 0 . 9 | - 2 3 . 3 1 2 i 2 4 . 6 2 7 C H L B J 3 5 4 7 . . 0 0 0 4 - 3 8 . 7 6 8 ] . 9 7 0 ] 0.6 1 0-0 0,0 0.0 0.0 ] - 0 . 6 MANY 1 2 . 3 7 C H L C ] 3 5 6 8 . - 0 0 0 4 1- 2 . 3 0 4 I . 9 7 9 1 1 7 - 1 3 0.0 0. 1 0-4 - 0 . 5 | - 1 5 . 0 1 1 | 1 5 . 2 2 6 C T J 3 5 4 2 . . 0 0 0 { 4 1- 1 . 3 5 2 J . 9 6 6 i 3 4 - 3 1 0.0 - 0 . 5 1-1 - 0 . 7 | - 2 6 . 8 1 2 1 2 6 - 8 2 7 BA J 3 5 2 1 . - 0 0 0 4 - 2 8 - 8 4 3 - 9 3 4 J 0 . 0 3 1 0 . 0 0 0 . 0 0 0 . 0 0 0 . 0 0 | - 0 - 0 3 MANY 1 0 - 0 7 8 CA | 3 5 2 4 . - 0 0 0 4 . 9 8 - 4 0 3 | . 9 4 3 | 0 . 5 7 ) 0 . 0 1 0 . 0 1 - . 0 1 0.0 | - 0 . 3 4 1 1 1 0 . 3 1 2 1 C T A J 3 5 2 1 . . 0 0 0 j 4 1.3 . 2 6 5 . 9 3 5 | 1. 18 I 0-02 - . 0 1 - . 0 1 0 - 0 1 | - 0 . 2 5 7 1 0 . 3 6 3 6 BC | 35 1 9 . - 0 0 0 j 4 . 4 1 - 7 4 8 - 9 2 8 1 0 . 0 6 1 0 . 0 0 0 . 0 0 0 . 0 0 - . 0 1 J - 0 . 0 6 MANY J 0 . 2 7 8 BCT | 3 5 1 7 . . 0 0 0 4 . 3 5 - 7 8 9 . 9 2 2 1 0 . 0 2 1 0 - 0 0 0.00 0 - 0 0 0 - 0 0 \ - 0 . 0 2 MANY \ 0 . 0 8 8 C C T J 3 5 1 6 . . 0 0 0 j 4 . 5 7 - 6 3 7 | . 9 1 9 3 0 . 4 8 1 0-00 0 . 0 1 0 . 0 0 - . 0 1 J - 0 . 2 5 1 1 | 0. 1 9 18 PGO J 11 8 3 . . 0 0 0 3 0. 8 - 4 6 5 j - 9 8 8 1 3 0 4 . , 1 7. 0. - 7 . N/A ; - 2 2 5 . 1 2 J 1 5 5 . 3 3 PNO j 11 6 5 - . 0 0 0 1 3 0. 4 . 6 6 6 - 9 8 5 1 2 6 3 . 1 - 4 . - 1 . 5 . N/A | - 2 0 0 . 1 2 1 1 4 8 . 3 3 R E S | 11 3 . 2 - 0 1 2 3 1.6 - 2 3 5 | - 8 0 0 | 4 4 . | 8 . 5 - 2 . 1 - 6 - 4 N/A - 3 7 . 2 6 | 2 5 . 2 3 6 PROD J 11 9.6 - 0 0 0 3 0. 5 - 6 0 7 | - 9 1 1 1 1 0 1 . J " 5 - - 3 - 8. N/A i - 6 4 . 1 2 J 1 3 9 . 2 7 PGODY | 11 6 8 . - 0 0 0 3 0. 8 . 4 7 3 | . 9 8 6 | 2 . 56 1 . 0 6 . 0 0 - . 0 6 N/A i - 1 . 8 5 1 2 1 1 . 2 7 3 3 P C D Y 1 11 8.9 - 0 0 0 3 0. 5 - 6 1 0 | . 9 0 5 I 0 - 8 4 | -- 4 6 - . 2 3 . 7 0 N/A i -. 5 2 1 2 1 1-12 2 7 PGOST | 11 1 5 - . 0 0 0 3 2- 1 . 1 5 1 | . 9 4 1 | 1 1 - 0 1 0-2 0-6 - 0 . 8 N/A ; - 5 . 9 1 8 1 6- 1 3 6 PNOST | 11 2 1 - . 0 0 0 | 3 0. 7 - 5 0 7 | . 9 5 6 1 9.5 | 0.0 0.3 - 0 . 3 N/A | - 5 . 3 18 1 4.9 3 6 R E S S T J 11 2. 7 . 0 2 9 3 0.2 - 8 4 2 ; . 7 5 9 1 1-7 I 0-0 0- 1 - 0 . 1 N/A j - 1 . 3 6 1 1- 4 21 A S S | 11 8.8 . 0 0 0 3 1-0 . 4 0 3 J . 9 0 4 | 3.8 I - 0 . 4 0.2 0-2 N/A ; - 2 - 0 2 7 | 4-0 6 E X C S T J 5 5 9 - . 0 0 0 ] 3 0. 1 - 9 3 9 | - 9 8 4 i 4.0 ] 0.0 - 0 . 1 0. 1 N/A j - 2 . 6 1 2 | 4.2 3 6 A L P H A G ] 11 8.0 .000 | 3 3 7 . . 0 0 0 ; . 9 4 1 1 48.1 1 - 1 5 . 4 - 1 . 7 1 7 . 1 N/A | - 1 9 . 7 2 1 1 1 7 . 9 3 0 A L P H A C ] 11 3 . 1 .015 | 3 2 2 . .000 ! .888 1 15.7 1 - 6 . 3 -0.6 7-0 N/A | - 8 . 2 2 1 I 6.2 9 137 Table 22. Resu l t s for the p r o d u c t i v i t y v a r i a b l e s , averaged f o r the three p e r i o d s of v a r i a b l e f l u s h i n g r a t e s i n .EXP5A, with EXP5B r e s u l t s during the sane time period as a comparison. Sampling times i n c l u d e Days 6,9 and 12 f o r P e r i o d 1 (F.I.=.25/day), Days 18,21,24,27 f o r Eeriod 2 (F.B.=,50/day) and Days 30,33,36,38 f o r Pe r i o d 3 (F.B. = . 10/day) . Means f o r the t o t a l time period are found i n Table 20 and Table 21,, EXP5A F . B . = . 2 5 / L A Y F . E . = . 5 0 / D A T F , I . = . 1 0 / t A 1 VAB 1 STN 1 N MEAN S.D. | N MEAN S. D. ; 1 M MEAN •£.C. . PGO 1 1 2-4 J 9 1 1 1 . 4 6 . 3 ! 1 2 2 2 4 . 8 8 . 4 •12 1 3 2 . 6 2.0 PGO 1 2-4 | 9 6 9 . 4 5 . 1 1 12 1 8 2 . 8 5 . 8 12 S 3 . 5 4 . 9 E E S 1 2-4 | 9 4 2. 2 0 . 6 I 1 2 4 2 . 2 1 . 3 I 1 2 4 0 . 2 2 . 1 FB O E I 2-4 | 9 5 6 . 4 0 . 2 1 2 7 0 . 3 0 . 6 1 2 5 5 . 2 3.6 P G O S T 1 2-4 | 9 1 6 . 6 1 3 . 2 8 1 2 8.4 4 . 4 0 1 2 8.2 2 . 2 5 PNOST 1 2-4 | 9 7 . 1 3 . 0 6 I 12 7.0 4. 4 2 12 5.5 1.79 E E S ST 1 2-4 i 9 9.5 1 3 . 1 | 1 2 1.5 0 . 7 0 | 12 2.6 1 . 3 0 ASS 1 2-4 | 9 6.0 2.3 1 2 2.5 0.94 1 2 3.3 0 . 7 0 PGODY 1 2-4 J 9 1 . 0 0 - . 4 1 4 | 1 2 1 . 9 6 . 5 9 2 I 12 1. 11 .5 13 FCDY. 1 2-4 j 9 0 . 4 7 . 3 2 2 I 1 2 € . 5 8 . 1 7 3 1 2 0 . 4 5 . 1S5 A L P B A G | 2-4 J 9 4 3 . 3 3 1 . 3 9 J 1 2 4 7 . 7 1 7 . 7 2 | 12 2 9 . 3 1 1. 12 A L P H A C ! 2-4 | 9 1 5 . 3 5 . 6 8 | 1 2 1 5 . 4 8 , 6 1 1 2 1 1 . 7 3 . 4 5 APGO J 2-4 { 9 0 . 4 5 . 2 0 3 | 1 2 0 . 3 4 . 1 4 5 i 1 2 0 . 4 3 - 1 3 5 E P G C 1 2-4 | 9 0. 4 5 . 2 7 6 1 12 0 . 2 1 . 1 4 6 1 2 0 . 3 2 . 1 4 2 E X P 5 E PGO 1 2-4 | 9 2 0 6 . 1G5.6 | 1 2 2 6 2 . 1 3 4 . 2 I 1 2 4 2 0 . 5 6 . 1 PGO J 2-4 | 9 1 7 9 . 8 9 . 9 | 1 2 2 2 5 . 1 1 6 . 8 I 1 2 3 6 6 . 1 4 . 2 E E S 1 2-4 | 9 2 7 . 2 6 . 8 | 1 2 4 6 . 2 6 , 6 1 2 5 5 . 2 2 . 4 PBOD 1 2-4 J 9 1 1 0 . , 6 8 . 7 | 1 2 1 0 5 . 8 8 . 2 1 2 9 1 . 2 6 . 3 P G G S T 1 2-4 | 9 1 2 . 6 1.7 0 I 12 7.1 1 . 8 S j 1 1 2 1 3 . 7 2 . 7 7 P N O S T 1 2-4 | 9 1 0 . 9 1 .91 1 2 6. 1 1.74 | 12 1 1 . 9 2 . 0 9 E E S S T 1 2-4 | 9 1.7 1 . 1 1 I 1 2 1.5 1 . 0 7 1 2 1.8 0 . 6 6 A S S 1 2-4 I 9 6.5 1.9 0 | 1 2 2.6 1. 12 12 2.9 0.5 2 PGOPY 1 2-4 J 9 1 . 7 8 . 9 1 3 I 12 2 . 2 0 . 8 7 4 12 3 . 5 0 .4 6 7 P C D Y 1 2-4 | 9 0 . 9 3 . 5 9 7 1 2 0 . 8 7 . 7 0 4 | 1 2 0 . 7 5 . 2 1 8 A L P H A G | 2-4 | 9 3 5 . 5 1 0 . 6 8 | 1 2 4 6 . 1 2 4 . 4 2 I 1 2 5 7 . 7 1 6 . 5 6 A L P B AC| 2-4 | 9 1 8 . 7 9 . 6 7 | 1 2 1 6 . 4 8. 2 6 12 1 2 . 7 6 . 2 2 A I G C 1 2-4 | 9 0 . 5 2 . 0 4 7 | 1 2 0 . 3 8 . 1 5 6 1 2 0 . 2 2 . 0 6 4 E P G O 1 2-4 ) 9 0. 1 3 . 1 0 6 | 12 0 . 2 0 . 1 0 5 1 2 0 . 1 3 . 0 4 5 138 Table 23., P r o d u c t i v i t y component a n a l y s i s f o r IXP5. RPGO,APGO and EPGO repr e s e n t the p i o p c r t i o n of gross p r o d u c t i v i t y due to r e s p i r a t i o n , a s s i m i l a t i o n and e x u d a t i c n . ESTPGO i s the estimated gross p r o d u c t i v i t y based on t i e sub-model: ESTPGO=BPGO • APGO * EPGO . See the t e x t f o r an e x p l a n a t i o n of the r e s u l t s . EXP5 - TASK A ANALYSIS OF VARIANCE VAR |GRAND 1 MIAN RPGO | 0.29 APGO j 0.48 EEGO | 0.29 ESTPGO | 1.06 RPGO ] 0.32 APGO | 0.40 BUIT R BY STN A SIG EY TIME T SIG TOTAL N SIG .798 .791 .657 ,825 .888 .799 3 .062 3 .4 89 3 .54 9 3 .724 3 . 170 3 .238 5 .287 5 .089 5 .363 5 .042 11 .000 11 .012 15 .13 1 15 .145 15 .475 15 .0 86 3 3 .0 0 0 33.016 EXP5 - TASK B ANALYSIS OF VARIANCE VAR JGRAND l MEAN RPGO | 0.14 APGO J 0.36 EPGO | 0.34 ESTPGO I 0.8 4 I RPGO ] 0. 1 5 APGO J 0.36 MULT 1 BY STN J BY TIME A SIG | T SIG TCTAI N SIG .856 .951 .585 .781 .764 .890 3 .063 3 .352 3 .081 3 .353 3 .986 3 .4 27 5 .063 5 .000 5 .000 5 .122 11 .024 11 .000 15.046 15 .000 15 .000 15 .165 33 .0 45 33 .000 T a b l e 24. Two-stage con t i n u o u s c u l t u r e of h e r b i v o r e s . S t a t i s t i c a l summary o f environmental v a r i a b l e s during each o y s t e r experiment (t=8) f o r the fo u r tanks (Tank 4= C o n t r o l ) . ANOVA's are f o r Tanks 1,2 and 3 on l y . See Appendices 1 and 2 f o r a d e s c r i p t i o n o f the v a r i a b l e s . | ANOVA BY EXP. I | EXP. I I EXP. I I I J EXP. IV i EXP TANK VAR TANK | MEAN S.D. j MEAN S.D. MEAN S.D. | MEAN S.D. | S1G. SIG. TEMP 1 1 1 8 . 4 2 . 4 4 | 2 0 . 1 1 . 17 2 3 . 3 2 . 2 9 J 1 9 . 5 1 . 5 1 2 1 1 8 . 5 2 . 4 0 | 2 0 . 1 1 . 12 2 3 . 3 2 . 3 1 | 1 9 . 4 1 . 5 3 | . 0 0 0 . 7 9 3 3 I 1 8 . 4 2 . 3 6 | 2 0 . 4 1 . 16 2 3 . 5 1 . 8 6 l 1 9 . 8 1 . 6 7 4 ] 1 8 . 4 2 . 3 8 | 2 0 . 0 1 . 16 2 3 . 1 1 . 9 6 | 1 9 . 4 1 . 4 8 STKUP 1 J 2 1 . 2 1 4 . 7 9 | 1 7 . 7 8 . 8 0 7 . 2 6 . 2 5 | 1 8 . 5 6 . 7 1 2 I 2 2 . 6 1 4 . 8 8 J 2 5 . 4 1 1 . 6 0 8 . 1 6 . 8 6 1 2 6 . 2 7 . 6 9 | . 0 0 0 . 0 5 0 3 I 2 3 . 1 1 5 . 4 7 J 3 0 . 4 1 4 . 4 9 8 . 1 6 . 9 2 i 2 9 . 7 9 . 6 0 4 I 1 5 . 3 1 0 . 4 0 J 1 2 . 1 7 . 0 0 5 . 8 4 . 9 6 | 1 0 . 3 5 . 7 3 BA 1 ] . 1 9 5 . 1 9 4 7 | . 0 3 1 . 0 4 6 8 . 4 0 0 . 4 4 1 6 | . 0 1 9 . 0 2 0 2 2 I . 2 6 9 . 1 3 0 6 | . 0 6 2 . 0 7 4 4 . 6 6 8 . 4 5 1 4 J . 0 6 8 . 0 5 5 7 | . 0 0 0 . 1 8 6 3 | . 3 2 6 . 1 5 6 9 | . 0 5 6 . 0 5 7 9 . 4 6 3 . 3 0 4 4 J . 1 5 7 . 1 2 7 4 4 1 . 0 7 0 . 0 8 3 3 | . 0 0 0 . 0 0 0 0 . 2 2 9 . 2 4 4 0 J . 0 1 4 . 0 2 2 3 OXYUP 1 J 3 . 3 9 1 . 3 7 5 | 4 . 4 7 1 . 1 9 8 , 3 . 9 7 1 . 1 1 2 | 4 . 7 7 0 . 7 9 3 2 1 3 . 8 4 1 . 1 8 0 J 5 . 5 7 1 . 5 7 0 | 4 . 16 1 . 6 6 2 | 5 - 1 8 0 . 6 6 4 J . 0 0 0 . 0 5 5 3 | 4 . 0 7 1 . 2 5 8 ] 6 . 3 1 1 . 6 9 9 | 3 . 4 3 1 . 2 3 1 j 5 . 7 4 0 . 5 6 6 4 1 1 . 8 7 1 . 2 7 6 | 4 . 3 7 1 . 0 6 5 3 . 7 4 0 . 8 9 8 | 4 . 2 4 0 . 7 5 7 CTA 1 | 1 . 3 5 . 1 2 0 1 1 . 5 0 . 2 1 9 | 3 - 8 0 2 . 4 6 1 J 1 . 4 8 . 0 5 6 2 I 1 . 4 9 . 3 2 6 | 1 . 5 5 . 1 9 9 | 3 . 7 2 1 . 0 3 8 | 1 . 4 5 . 0 9 1 | . 0 0 0 . 9 7 0 3 J 1 . 5 5 . 2 8 5 | 1 . 4 7 . 2 2 0 ] 3 . 7 6 0 . 7 5 5 I 1 . 5 7 . 1 8 8 4 ] 1 . 5 6 . 2 5 6 I 1 . 5 4 . 1 8 1 J 4 . 9 2 2 . 0 6 0 | 1 . 5 2 . 1 5 2 T a b l e 25. D e s c r i p t i v e s t a t i s t i c s f o r the s i x growth v a r i a b l e s f o r each c u l t c h at the s t a r t o f each of the fou r h e r b i v o r e experiments; TIME=4 summarizes the f i n a l measurements. LENGTH WIDTH DEPTH TOTAL WGT MEAT WGT SHELL WGT I.D. MEAN S.D. MEAN S. D. MEAN S.D. •.. MEAN S.D. MEAN S.D. MEAN S-D. N TIHE=0 CULTCH ALL 5.7 0.97 3.2 0. 61 1.7 0-30 12.8 4.70 4.0 1.51 8. 8 3-27 96 CULTCH 1 4.0 0.39 2-8 0- 40 1-4 0-21 5.7 0.97 1.8 0. 38 3.9 0.68 8 CULTCH 2 5. 1 0.27 3-4 0- 35 1.7 0-15 10.5 1-66 3.6 0.76 7. 0 0.98 8 CULTCH 3 5. 1 0.40 2.8 0- 62 1.7 0-24 9.7 3.59 3- 1 1.26 6.6 2.37 8 CULTCH 4 4.9 0. 19 3. 1 0. 53 1.5 0.20 8.9 2-01 2.8 0.9 1 6. 1 1. 18 8 CULTCH 5 5.2 0.39 2-9 0- 50 1.7 0-36 10.2 2-38 3-2 0.75 6. 9 1.72 8 CULTCH 6 6.0 0. 19 3- 6 0. 34 1.6 0.31 14. 4 2- 88 4.7 1. 10 9.7 1.88 8 CULTCH 7 5.8 0.26 3.2 0- 45 1.7 0-23 12.8 2.37 4.0 0.94 8- 8 1. 52 8 CULTCH 8 5.8 0.43 3-1 0- 83 1.9 0.24 14. 1 3.50 4.3 1.16 9.8 2-48 8 CULTCH 9 5.8 0. 16 3- « 0- 42 1.6 0.31 13.2 2.85 4. 1 1-05 9. 1 1-80 8 CULTCH 10 6.9 0.36 3.9 0. 73 1.9 0.31 18.3 3.8 4 5.6 1. 41 12.7 2.46 8 CULTCH 11 7.2 0.26 3.6 0. 70 1.9 0.29 18.3 2-29 5.5 1.17 12.8 1-50 8 CULTCH 12 7. 1 0.37 3-2 0. 39 1.9 0.24 18. 1 3.60 5.4 1.20 12.7 2-55 8 TIME=1 CULTCH ALL 5.8 0.95 3.4 0. 61 1-8 0.28 14.1 4-87 4.5 1.56 9.6 3-37 96 CULTCH 1 4.1 0-38 2.9 0. 40 1.5 0. 18 6.7 1- 1 1 2. 1 0.41 4.6 0.78 8 CULTCH 2 5.3 0.35 3.5 0. 55 1-8 0.12 12-0 1.74 4. 1 0.73 8.0 1.06 8 CULTCH 3 5. 1 0.39 2.9 0. 59 1-7 0. 24 10-6 3-77 3-6 1.29 7. 1 2- 45 8 CULTCH 4 5.0 0-21 3. 1 0. 47 1.6 0. 19 10-0 2.06 3.3 0-87 6.8 1-26 8 CULTCH 5 5-3 0.42 3-0 0. 44 1-7 0-36 1 1-2 2-37 3-5 0.80 7. 6 1-81 8 CULTCH 6 6.1 0.3 0 3-8 0- 31 1.7 0.26 15-7 2-74 5.2 1.05 •10. 5 1.80 8 CULTCH 7 6-0 0.29 3. 5 0. 53 1.8 0-23 14.4 2.70 4.6 0-98 9.8 1.78 8 CULTCH 8 5.8 0.39 3-2 0. 84 1.9 0-23 15. 1 3-61 4.6 1.22 10. 4 2.52 8 CULTCH 9 6.0 0.20 3-5 0. 39 1-7 0-28 15.2 2-87 4.9 ' 1.01 10. 3 1. 89 8 CULTCH 10 6.9 0.37 3. 9 0. 74 2.0 0.28 19.7 4. 1 1 6. 1 1-49 13. 7 2-66 8 CULTCH 11 7.3 0-29 3.7 0. 67 1-9 0.26 19.7 2-64 6- 1 1. 25 13-6 1.68 8 CULTCH 12 7.1 0.42 3.4 0. 37 1.9 0.23 19. 1 3-99 5.9 1-28 13- 3 2.82 3 o LENGTH WIDTH DEPTH TOTAL WGT MEAT WGT •• SHELL WGT I.D. MEAN S. D. MEAN S . D. , MEAN S- D. , MEAN S-D. MEAN S.D. MEAN S-D. N TIME=2 CULTCH ALL 6. 0 0.93 3. 6 0.67 1.8 0.25 15.9 5. 27 5.1 1.71 10.8 3. 63 96 CULTCH 1 4.4 0.5 0 3- 2 0. 55 1.6 0. 16 8.1 1.36 2.6 0. 46 5. 6 0.97 8 CULTCH 2 5.6 0-52 3.9 0.62 1-9 0- 12 14.3 2. 10 4.8 0.69 9.4 1.48 8 CULTCH 3 5.3 0.38 3.0 0.54 1.7 0. 18 1 1.7 4. 1 1 4-0 1.57 7.7 2-58 8 CULTCH 4 5.3 0.37 3.3 0.41 1.6 0-23 12. 1 2.04 4. 1 0.83 8. 1 1- 35 8 CULTCH 5 5.4 0-47 3. 1 0. 40 1-8 0.33 12.3 2.4 8 3.9 0.86 8. 4 1. 73 8 CULTCH 6 6.4 0-45 4. 1 0.38 1.8 0-22 17. 4 2.76 5-9 1.03 11. 5 1.90 8 CULTCH 7 6.2 0.33 3.8 0-69 1.9 0.24 16.2 3- 18 5-2 1.06 11.0 2. 15 8 CULTCH 8 5.9 0.40 3.4 0.90 1.9 0-24 16.7 3-98 5.2 1.39 11. 5 2-70 8 CULTCH 9 6. 1 0.28 3. 8 0.50 1-9 0.24 16.9 3.02 5.5 1-03 11. 4 2-05 8 CULTCH 10 6.9 0.36 4. 1 0.72 2.0 0.26 22.6 4-72 6.9 1.69 15. 6 3.08 8 CULTCH 11 7.4 0.35 3.9 0.74 2-0 0.25 21-6 3. 19 6.8 1-36 14. 7 2.04 8 CULTCH 12 7.2 0.50 3.7 0-45 2.0 0-21 21. 1 4.75 6-7 1.49 14. 4 3-36 8 TIME=3 CULTCH ALL 6.1 0.93 3.8 0.71 1.9 0-27 17.2 5-66 5-4 1.78 11. 8 3. 96 96 CULTCH 1 4.5 0.45 3. 6 0.61 1.6 0-21 9.3 1.53 2-8 0.58 6.5 1-16 8 CULTCH 2 5-6 0.51 4. 1 0-70 2-0 0.23 15-5 2.40 5.2 0.82 10. 3 1.70 8 CULTCH 3 5.5 0.43 3.3 0.59 1.7 0.20 12.7 4. 19 4.2 1.53 8. 6 2.69 8 CULTCH 4 5.3 0.34 3. 3 0-40 1.7 0.21 12.7 2-87 4. 1 1-11 8.6 1.85 8 CULTCH 5 5-4 0.51 3.2 0-48 1.9 0-36 13-2 2-75 4.0 0.95 9. 3 1.94 8 CULTCH 6 6.4 0.4 3 4-2 0.51 1-8 0.21 18.4 3- 17 5.8 1-23 12- 6 2. 11 8 CULTCH 7 6-2 0.33 3-9 0-72 1.9 0.20 17-4 3. 46 5.4 1. 11 12. 0 2-38 8 CULTCH 8 6- 1 0.46 3-6 1.03 2-0 0. 18 18.0 4.37 5.4 1. 40 12. 6 3.04 8 CULTCH 9 6-2 0.38 4-0 0.60 1-9 0. 33 1 8- 7 3.37 6.0 1.08 12.7 2-35 8 CULTCH 10 7- 1 0-28 4.3 0.77 2- 1 0.26 24.8 5.09 7-4 1.60 17.4 3.57 8 CULTCH 11 7.3 0.37 3.9 0-74 2.0 0-26 22-9 3-65 7. 1 1. 44 15.9 2.40 8 CULTCH 12 7.3 0.48 3.9 0.50 2-0 0.22 22- 1 5-13 6-9 1.51 15. 3 3.73 8 L E N G T H WIDTH D E P T H T O T A L WGT MEAT WGT S H E L L WGT I . D . MEAN S.D. MEAN S. D. , MEAN S- D. . MEAN S. D- MEAN S.D. MEAN S.D. N TIME=4 C U L T C H , ALL 6. 1 0-91 3.8 0- 74 1.9 0.27 19.2 6. 15 6,1 1.97 13.2 4.27 96 C U L T C H 1 4.6 0.4 3 3-7 0. 71 1.7 0.21 10.5 1.77 3.2 0- 57 7. 4 1.30 8 C U L T C H 2 5.6 0-4 1 4. 1 0. 64 2.0 0.22 18. 1 2.9 4 5.8 0-7 2 12. 3 2-44 8 C U L T C H 3 5.5 0.41 3-2 0. 85 1.8 0.20 14.5 4.51 4.9 1.69 9.7 2-85 8 C U L T C H U 5.3 0.31 3-3 0. 41 1.7 0.25 14.6 2-96 4.7 1- 24 9.9 1.78 8 C U L T C H 5 5.4 0.43 3- 2 0. 46 1.8 0. 33 14.6 3-19 4.5 1. 13 10.1 2.23 8 C U L T C H 6 6-5 0-41 4-3 0. 47 1.9 0.22 20.8 3-21 6-7 1-21 14. 1 2-26 8 C U L T C H 7 6.2 0-33 3.9 0. 69 1-9 0.21 19.7 4.29 6.3 1-34 13. 4 3.00 8 C U L T C H 8 6-1 0.49 3-6 1. 04 2. 1 0.20 19.5 4.97 6. 1 1-57 13.4 3.46 8 C U L T C H 9 6.3 0-35 4-0 0. 51 1-9 0.32 21.6 3-58 6-7 0-98 14.8 2.81 8 C U L T C H 10 7- 1 0-23 4.3 0. 79 2. 1 0.22 27.0 5-42 8-4 1.73 18. 5 3-77 8 C U L T C H 11 7.3 0-39 3.9 0. 76 2- 1 0.23 25.2 4-50 7-9 1-64 17. 3 2-99 8 C U L T C H 12 7-4 0.48 4-0 0. 45 2.0 0.23 24.4 5-96 7.7 1.75 16.7 4.32 8 N J 143 Table 26. Resul t s c f the net and percent i n c r e a s e s per o y s t e r f o r t i e s i x growth v a r i a b l e s , i n c l u d i n g s i g n i f i c a n c e l e v e l s f o r the e f f e c t c f s i z e and de n s i t y on g r c i t h . The *,**,**• i n d i c a t e a s i g n i f i c a n t l i n e a r r e l a t i o n at the .05, .01 and .001 l e v e l s r e s p e c t i v e l y . , NET1 NETW "N ET D EXP ME UN SIZE BENS MEAN SIZE DENS MEAN SIZE DENS I . 104 . 112 .12 1 . 145 .003 .271 .040 .007 ,003 * * ** I I .174 .012 .4 07 .242 .849 .106 .076 . 122 .008 ** ** I I I .065 . 533 .578 .168 .084 .541 .056 .532 .911 IV .040 .492 .623 .022 .536 .817 .018 ,457 ,96 2 NETWT NETWM NETWS EXP . ME UN SIZ E DENS MEAN SIZE DENS MEAN SIZE DISS I 1.28 .041 .00 0 0.48 .070 .005 0.81 .156 .000 *** *** *** II 1.79 .023 .003 0.65 ,007 .001 1. 13 . 103-.€06 ** ** *** * * ** I I I 1.24 .036 .315 0.21 -450 .032 1. 03 = .028 .5 70 * * * IV 2.06 .014 .002 0.72 .000- .098 1. 35 .259 .000 *** PERL EERW I EE D EXP MEAN SIZE DENS MEAN SIZE DENS MEAN SIZE DENS I - 012 . 00 3-,252 .047 .009- .443 .027 .002 .010 *** ** ** I I .032 .goo-- .65 3 .07 5 .847 .117 .047 .025 .023 *** * ** I I I .011 . 196 .318 i048 .023 .2 58 .033 .519 ,S56 IV .007 T .597 .564 .006 .545 .7 66 .012 .436 .97 2 PEEWT PERWM FIEWS EXP MEAN SIZE DENS . ME AK SIZE DENS MEAN SIZE DINS I .111 .000 .003 .138 .021 .294 .102 .000 .006 *** ** ** *** ** I I .135 . 0 00 .083 .154 .008 .117 .126 . 000 .140 *** * ** *** I I I • 081 .003 if .277 .044 .249 .103 .099 .003-•4* .606 IV .125 . 005 = .002 , 139 .674 .720 .120 .005 .000 *** *** *** 144 Table 27. Non-linear l e a s t squares f i t (LSF), using a g r i d search method (Bevington,1969), of the p r o d u c t i v i t y , P 8 (ug C/ug CHLA/hr), verses l i g h t , E AE ( l y / m i n ) , data f o r both the •TA NE * and •SHITE' h y p e r b c l i c models. The parameter A (1) corresponds to PMAX and re p r e s e n t s the naxia um net p r o d u c t i v i t y (S e«as set tc zero f o r the c a l c u l a t i o n s ) . The subroutine parameters are descr i b e d at the end of the Table. I. TANK MODEL P B = PMAX*TANH(S*PAS/PMAX) - Bfe 1. P ^S I - 14 DEG,(BLOCK),NAIEHA=2,N=7,P.NET ALPHA,S = 1 1 . 8 3 X(I)= 0.043 0. 103 0. 154 0.231 0.317 0.377 0.488 Y(I) = 0. 320 1.030 1.650 2.500 3.220 3.250 3.380 YFIT(I) = 0. 506 1. 182 1.705 2.372 2.S32 3.217 3.569 NPTS= 7 NTEBMS= 1 MCDE= 0 A(1) INITIAL= 3.900 FINAL= 3.986 DELTAA(1) INITIAL= 0.050 FINAL= 0.033 SIGMAA(1)= 1.219 CHISQB= 0.039 AVG Y(I)= 2.193 GAMM A= 0. 1966 1 GAMMAM= 0.08S66 2. P VS I - 16 DEG,(BLCGB),NALFHA=2,N=7,p.NET ALPHA,S = 21.83 X(I)= 0.043 0. 103 0. 154 0.231 0.317 0.377 0.488 Y(I)= 0.200 1.510 2. 150 3.960 6.050 5. 190 5.830 YITT(I) = 0. 932 2. 160 3.083 4.205 5.076 5.487 5.952 NE1S = 7 NTEEMS= 1 MODE= 0 A(1) INITIAL= 6. 200 FINAL= 6.392 DELTAA (1) INITIAI= 0.050 FIHAL= 0.067 SIGMA A (1) = 1.012 CHISQB= 0.588 AVG Y (I) = 3.556 G AMMA= . 2. 93949 GAMMAM= 0.82670 3. P VS I- 18 DEG, (BLOCK) , N AI PH A=2 , K= 7, P.NET fiIFHA,S = 25,83 X(I)= 0. 043 0. 103 0, 154 0.231 0.317 G.377 0.486 Y(I)= 0. 180 1.730 2.680 4.590 6.650 7.260 7.5 10 YFIT(I)= 1, 104 2.578 3.714 5. 156 €.356 6.961 7.70 0 NPTS= 7 NTEEMS= 1 MCDE= 0 A(1) INITIAL= 8.500 FINAL= 6.553 DELTAA (1) INITIAL= 0.050 FINAL= 0.0 17 ' SIGMA A (1)= 1.200 CHISQB= 0.667 AVG 5 (I)= 4.400 G A M M A= 3.33268 € AMM AM= 0.75743 145 4. P VS .1-20 DEG, (BLCOH) ,NALPHA*2,N=7,P. SET ALEHA,S = 3 1 . 8 9 X(I)= 0. 043 0. 1.0.3 0. 154 0.231 .0.3 17 0. 377 0.48€ Y ( I ) * 0.150 -1.340 3.6S0 6.010 7.350 6.780 8.66G YFIT(I) = 1.362 3. 165 4.53 1 6.217 7.557 8.203 8.952 NETS* 7 NTEBM S = 1 MODE* 0 A(1) INITIAL* 9.200 FINAL* 9.707 .DE-XT A A (1) INITIAL* 0.050 FINAL* 0.167 SIGMAA (1)- 1.071 CHISQB= 1.187 A VG Y (I) = 5.169 GAMMA- 5.93326 G A M M A R= 1. 14795 5. P VS I ~ 20 PEG,(POST-BLOOM),NALPBA=2,N=7,P.NET ALPHA,S •= 31.17 X (I)= 0. 043 0. 103 0. 15 4 0.231 0.317 C. 377 0.466 Y(I)= 0. 160 2.030 3. 230 5.950 6.760 7.090 9.000 YFIT(I) = 1. 330 3.074 ,4.371 5.92 1 7.096 7.635 6.228 NPTS= 7 NTEBMS*' 1 MODE* G A(1) INITIAL* 8.700 FINAL* 8.753 DELTA A (1) INITIAL* 0.050 FINAL= 0.017 SIGMftft(1) = 0.982 CHISQE* 0. 953 A VG Y <!)= 4.889 GAMM A* 4.76638 GAMMAM* 0. S75 01 6. ,P VS I - 18 DEG, (POST-BLOOM) ,NALFEI=2,N=7,E.NET ALPHA,S = 24.50 X(I) = 0. 043 0.103 0.154 0.231 0.317 0.377 0.486 Y ( I ) * 0. 130 1.600 2.690 4.610 5.760 6.640 6.640 YFIT(I)= 1.047 2.432 3.482 4.779 5.811 6. 310 6.886 NPTS= 7 NTEBMS* 1 MODE* 0 A(1) INITIAL* 7. 200 FINAL* 7.474 DELTAA (1) INITIAL* 0.050 FINAL* 0.083 SIGMAft(1) = 1.068 .CHISQB* 0.460 A VG 1 ( 1 ) - . 4.039 GAMMA* 2.30191 GAMMAM* 0.56SS8 7. P VS I - 16 DEG, (POST-BLOOM) ,N ALFBA=2, N=7, P. N E3 ALFB A ,S = 20.50 X(I) = 0. 043 0. 103 0. 154 0.231 0.317 0.377 0.486 Y (I) = 0. 120 1.350 2.620 3. 780 5.020 4.S1G 6.010 YFIT(I) = 0.876 2.034 2.912 3.994 4.853 5. 268 5.747 NETS* 7 NTEBMS* 1 MCDE= 0 A(1) INITIAL* 6.200 FINAL* 6.229 D EXTA ft (1) INITIAL* 0.050 FINAL* 0.017 SIGHAA(1)* 1.080 CHISQB* 0. 26 4 AVG Y(I)= 3.430 GAMMA* 1. 31836 GAMM AH* 0. 38436 146 I I . SMITH MODEL: P 8 = PMAX*S*PAB/(SQET ( (EMAX**2) •((S*PAB)**2) ) ) - K B 1. P VS I- 14 DIG, (BLOOM) , NALPHA=2,N=7,E. NET ALP HA, S = 11.83 X(I) = 0.043 0. 103 0. 154 0. 231 0.31 7 0.377 0.488 Y(I) = 0. 320 1. 030 1.650 2.500 3.220 3.250 3.380 YFIT(I) = 0.506 1.178 1.695 2.351 2.9 10 3. 207 3.605 NETS= 7 NTEBM S= 1 MCDE= 0 A(1) INITIAL-55 3. 900 FINAL= 4.615 DELTAA(1) INITIAL- 0.050 FIN AL= 0.233 SIGMAA(1) = 1.501 CHISQB= 0. 046 AVG Y LI) = 2.1 S3 GAMMA= 0.22868 GAMMAM= 0.10429 2.,P VS I - 16 DEG,(BLOOM),NALPHA=2,N=7,P.NET ALPHA,S = 21.83 X(I)= 0. 043 0. 103 0. 154 0.231 0.317 0. 377 0.488 1(1) = 0. 200 1.510 2. 150 3.960 6.050 5.190 5.830 YFIT(I) = 0. 931 2.149 3.053 4. 148 5.020 5.458 6.017 NETS= 7 NTEBMS= 1 MCEE= 0 A(1) INITIAL= 6.200 FINAL= 7.292 DELTAA(1) INITIAL= 0.050 FIN AL= 0.367 SIGMA A (1)= 1.253 €HISQE= 0. 592 AVGY(I)= 3.556 GAMMA= 2. 96142 GAMMA K= 0.83286 3. P VS I - 18 DEG,(BLOOM),NALPHA=2,$=7,E.NEl ALPHA,S = 25.83 X(.I)= 0. 043 0. 103 0. 154 0.231 0.317 0.377 0.486 Y(I)= 0. 180 1.730 2.680 4.590 6. 650 7.260 7.510 YFIT(I)= 1. 104 2.568 3.688 5. 103 6. 295 6.923 7.75S N£TS= 7 NTEBMS= 1 MCCE= 0 A(1) INITIAL= 8.500 FINAL= 9.844 DELTAA (1) INITIAL= 0.050 FINAL= 0.450 SIGMAA (1)= 1.496 CB.ISQB= 0. 664 AVG Y(I)= 4.400 GAMMA= 3.31827 GAMMA«= 0.75415 147 4. ? VS I - 20 DEG, (SLOCK) ,NALEHA=2,N=7,P.NET ALPHA, S = 3 1 , 8 9 X(I) = 0. 043 0. 103 0, 15 4 0. 231 0,317 0.377 0,486 Y(I) = 0. 150 1.340 3.690 6-010 7.350 6.780 8.860 YFIT(I) = 1.361 3*150 4.49 1 6. 137 7.472 6.153 S.033 NPTS* 7 NTEBMS* 1 MODE* 0 M l ) INITIAL* 9.2G0 FINAL* 11.093 DELIAA (1) INITIAL* 0.050 FINAL* 0.633 SIGMAS (1)= 1. 330 CHISQB* 1.167 A VG Y(I)= 5.169 GAMMA* 5. 83592 GAMMAM* 1.12912 5. P VS I - 20 DEG, (EOST-BLOGM) ,NAIFHA=2,N=7,F.NET ALPH B,S = 31. 17 X(I) = 0. 043 0.103 0. 154 0. 231 0.317.0.377 C.486 Y(I) = 0. 160 2.030 3. 230 5.950 6.760 7.GS0 9.000 YFIT(I) = 1.328 3.055 4,321 5.828 7.003 7. 583 8.313 NETS* 7 NTEBMS* 1 HCDE* 0 A(1) INITIAL* 8.700 FINAL* 9.927 DELTA A (1) INITIAL* 0.050 FINAL* 0.417 SIGMA A (1) = 1.216 CHISQB* 0.879 A VG Y(I)= 4,685 GAMMA* 4.39499 GAMMAM* 0.89903 6. P VS I - 18 DEG,(POST-BLOOM),NALFHA=2,N=7#E,NET ALEHA S * 24.50 X(I) = ' 0.043 0. 103 0. 154 0. 23 1 0. 317 0,377 0.486 Y(I)= 0. 130 1.600 2.690 4.610 5.760 6. 640 6.640 YIIT(I)= 1. 046 2.420 3.452 4.719 5.747 6.273 6.95/ NPTS* 7 NTEEMS* 1 MODE* 0 A(1) INITIAL* 7. 200 FINAL* 8.546 DELTA A (1) INITIAL* 0.050 FINAL* 0.450 S1GMAA(1)= 1.335 CHISQB* 0.450 A VG Y(I)= 4.039 GAMMA* 2. 25042 GAMMAM* 0.55723 7. P VS I - 16 BEG , (EOST-BLOOM) ,NALEBA=2,N=7,P.NET ALIH fl,S = 20.50 X(I)= 0. 043 0. 103 0. 154 0. 231 0. 317 0. 377 C,488 Y ( I ) * 0, 120 1.350 2. 820 3. 760 5.C20 4.S1C 6.010 YFIT(I) = 0.875 2.024 2.866 3.944 4.801 5. 238 5.802 NETS* 7 NTEBMS* 1 MODE* 0 A(1) INITIAL* 6.200 FINAL* 7.123 DEI-T A A (1) INITIAL* 0.050 FINAL* 0.30C SIGMA A (1)= 1.319 CHISQB* 0.251 A VG Y (I) = 3.43 0 GAMMA* 1. 25428 GAMMAM* 0. 36568 ma DESCRIPTION OF PABAHETEIS IN TEE NGN-LIK'E A E LSF SOEEOuIINE S - I n i t i a l s l c c e , ALPHA (Input Parameter) R -. Respiration (Input Parameter) X - Array of data pts. for indep var (PAB) Y - Array of data pts. for dep var (PB) NTERMS - No. of parameters MOLE - Determines method of wgting LSE A - Array of parameters of be estimated (A=1; A (1)=PMAX) DELTAA — Array of increments for parameter(s) A SIGMA A - Array of St. Dev. for para meter(s) A YFTT - Array of calculated values cf Y CHISQB - Seduced Chi Square for f i t AVG - Average Y (I) value GAMMA — Sum of ( (YFTT (I)-Y (I) ) **2) GAMMAM - GAMMA/AVG F i g u r e 1. E x p e r i m e n t a l f a c i l i t i e s f o r E x p e r i m e n t 1 incoming seawater-£ fi ite^U7-SEAWATER RESEVOIR HOLDING TANKS FOR GRAZERS -inflow tube I outflow tube EXPERIMENTAL TANKS jn situ sampling tubes 1 inflow pvc tubing outflow. S U R F A C E V I E W fluorescent lamps ' o o o o o o o o — 0 0 0 0 0 0 0 0 32. W VS EXPERIMENTAL TANKS ® VALVES Figure 2. Duplicate tank systems for Experiments 2 and 3 TANK. A TANK B Figure 3. Side view of the experimental f a c i l i t i e s f o r Experiments 2 and 3 SEAWATER RESEVOIR plywood c o v e r , IPS V PRIMARY PRODUCTION TANKS plexiglass cover. SCALLOP TRAYS or OYSTER CULTCH • VALVES SCALE: 1cm= 0.3 metre SIDE VIEW Figure 4. Side view of the experimental facilities for Experiment 4. SEAWATER RESEVOIR plywood cover, V ^ X ^ e . PRIMARY PRODUCTION TANKS plexiglass cover. SCALE: 1cm= 0.3 metre SIDE VIEW VALVES $ H-punp ® fo Figure 5. Two-stage culture systems for Experiment 5 153 H 2 H 3 C O N T R O L . A C C L I M A T I O N Figure 6. N i t r a t e concentration during Experiment IA Figure 7. N i t r a t e concentration during Experiment IB •Figure 8. Phytoplankton stock during Experiment IA _ . S U R f f l C E . _ M I D BOTTOM S A M P L I N G M Y If \ V >' f \\/ s 0 . 0 5 . 0 It N I S 1 0 . 0 T T 1 5 . 0 I 2 0 . 0 2 5 . 0 3 0 . 0 3 5 . 0 TIME (Dfir) 4 0 . 0 I 4 5 . 0 —I 5 0 . 0 5 5 . 0 6 0 . 0 6 5 . 0 7 0 . 0 Ln ON Figure 9. Phytoplankton stock during Experiment IB swrsct mo BOTTOM a SWUNG 0R1 A / \ / \ / \ / \ / \ //V ~ \ / V / 0.0 T S s . o 10.0 IS.O 20.0 2S.0 30.0 35.0 TIME (DAT) 40.0 — 1 — 45.0 n — SO.O - 1 — S5.0 60.0 6S.0 70.0 Figure 10. Primary productivity during Experiment IA PRIMARY PRODUCTIVITY - IA SURFACE WD e o n s * + DETRITUS B SRHPLJNG oar oo PRIMRRY PRODUCTIVITY (uG 1 4 C / L T T R E / H R ) . n ^ n n on 30.0 [00.0 150.0 203.0 i S O . O 330.0 350.0 410.0 <50.0 500.0 I I I I l _ 1 I 1 1 1 • OQ c H ro v. I •V v ! S s-r y 171 « ^ T3 l-f O Cu c o rt H" <! c 3 CN m ro ro 3 ts 6ST Figure 12. Primary p r o d u c t i v i t y (standardized) during Experiment IB Figure 13. Solar r a d i a t i o n during Experiment 2 1 6 2 F i g u r e 14. Temperature d u r i n g E x p e r i m e n t 2A q _ _ _ _ _ °i^ > £^  TTo iTo jjTo 2E0 iTo SE©- «tio 4Z0 ~sl.o TIME (DRY) 163 Figure 15. Temperature during Experiment 2B JNFLOV SURFACE HID K n o w OUTFLOW " ° 4 1 0 » ' • • * . o a.'.o T^o " i k s U 4.'o ^ TIME (DAY) 164 Figure 16. N i t r a t e concentration during Experiment 2A TIME (DRY! 1 6 5 166 Figure 18. Phytoplankton stock during Experiment 2A A / \ •V . 5URFRCE HID B3T10H OUTFLOW x SRMPL1NG DRY ho * * * * x ii I » to 11.0 "*~T—5 r~5 i-) x I Z/.o %.o 3/.o TIME (DAY) 3 4 .6 — i 1 Figure 19. Phytoplankton stock during Experiment 2B 168 Figure 20. Oxygen concentration during Experiment 2A a T o itlo 7^6 7£o 2/.* i£o sLe> <A.o t/i-a &).a TIME (DAY) 169 Figure 22. Primary productivity during Experiment 2A 1 7 1 Figure 23. Primary p r o d u c t i v i t y during Experiment 2B SURFACE HID. B8TT0M orio-LU rr x SRMPUNG OflV g o a. 172 Figure 24. Primary p r o d u c t i v i t y (standardized) during Experiment 2A S i 173 Figure 25. Primary productivity (standardized) during Experiment 2B cn". CJ ( J D —ri. C J » —. co C J CY. _= •—ICO _ O. l l l l / ' \ / U - \ : I' * i > ' / . ' 1 V " ! i I i i i . i ' • / v SURFRCE MID BOTTOM X SAMPLING DAY I.O * - 0 / / . O / * . © i / . O 34>4> 31.- ~' o 3ko tf/.o ti&.e> TIME (DAY) 1 7 4 175 Figure 27. Temperature during Experiment 3A imov SURFACE HID BOTTOM OUTFLOW ^ 77Z ~J^o zi^ A ° I 0 " ° — — TIME" (DAY) 176 Figure 28. Nitrate concentration during Experiment 3A S-4 4 UJ cc 32' UJ •— cc cc A i m o v SURFRCE _ HID BOTTOM OUTFLOW n SAMPLING DRY (5.H.B) x x x x x x x x x x x I O 4.0 11.© iL.o j i r o i t * ai'.o TIME IDRY) 177 Figure 29. Phytoplankton stock during Experiment 3A t o Figure 30. Oxygen concentration during Experiment 3A 179 Figure 31. Primary p r o d u c t i v i t y during Experiment 3A HID BOTTOM TIME (DRY) 180 Figure 32. Primary p r o d u c t i v i t y (standardized) during Experiment 3A - • ' ' • « x X i x x I x X T T | 1 1 i . 4-» n.o /Co xto X* - 0 JI.O ii.0 IHO *'o TIME (DflYJ 181 Figure 33. Solar radiation during Experiment 3B 182 183 Figure 35. N i t r a t e concentration during Experiment 3B 184 Figure 36. Phytoplankton stock during Experiment 3B SURFRCE HID BOTTOM CUTFLOW SAMPLING DAY (5.M.B) *7* fc.o (1.0 l~4> TIME (DAY) i 9>.o SI* 186 Figure 38. Primary p r o d u c t i v i t y during Experiment 3B ml SURFACE HID BOTTOM x SAMPLING DM I » M * > * ii I ii ii I ic £ I ii i i T" ii J ii I I I I l.o £.o ti-o lU.o 37-0 2-L o ?/.o 3C.0 *H-o *U,.o Si.o TIME (DAY] Figure 39. Primary productivity (standardized) during Experiment 3B 188 FIGURE 4-0 FORCING CONDITIONS DURING EXPERIMENT 4 SOLRR RROIRTION TANK fl im B FIGURE 4V TEMPERATURE DURING EXPERIMENT 4 IHfLOV S U R F R C t BOTTOM M I D OUTFLOW °. TRNK R 190 FIGURE M NITRATE DURING EXPERIMENT 4 IHFLoY SURFRCE BOTTOM MID OUTFLOW T R N K R 8,0 16.0 40.0 43.0 TRNK 0 T I ^ A R Y S ) 3 2 , 0 40.0 49.0 FIGURE .43 PHYTOPLRNKTON DURING EXPERIMENT 4 192 FIGURE W CHLB'.CHLR RATIO DURING EXPERIMENT 4 SURFRC£ MID BOTTOM OUTFLOW TRNK R r~—i 1 1 1 j r 32.0 40.0 48.0 16.0 '1ME?41°DRYS) TRNK B A. T T T 24.0 32.0 TINE (DAYS) 40.0 43.0 FIGURE 4-5 CRROTENOID:CHLR DURING EXPERIMENT 4 2P cc SURFRCE HID Bonem OUTFLOV vn TRNK R ZZ C M Q N o z -UJ a j g C E •_ C C -o o " — r — 8.0 T r T T r o.o IS.O 24.0 32.0 TIMbf I D R Y S ) 43.0 4 3 . 0 a in" TRNK B I—tn" CC C C 5 1 X Q Z. -UJ O H c r -u o • ma -] r 8.0 0.0 16.0 T IME?VDRYS) 32.0 43.0 4 3 . 0 FIGURE H OXYGEN DURING EXPERIMENT 4 INFLOW SURFRCE HID wnoH OUTFLOW TRNK R x .Vvr V " v : f \ / v s i / , v ; - ) — 8.0 0.0 T U - ° T I H ^ f t f l T S ) 40.0 48.0 TRNK B 0.0 e.o 43.0 — I — 49.0 195 FIGURE 47 GROSS PRIMRRY PRODUCTIVITY DURING EXPERIMENT 4 S U R F A C E Q MID © anion _ o 1 ° . cn a TANK A A GJ 9 A A • 0 g © © g _ _ © © m m A O 8 A< © A — I 1 J — — I 1 1 1 1 1 1 1 1 — 0.0 8.0 16.0 T ] | 1 ^ R Y S ) 3*.° «.0 CC 1 ° C J o _ J C M a. " a tn _ o a _ © TRNK B - O d a " B g CD © A © ~ • A B © ® A CO © 1 1 1 1 1 1 r — — I 1 1 1 1 0.0 6.0 16.0 --jj^.O 32.0 40.0 48.0 TIME IDRYS) FIGURE 4 8 RESPIRRTIQN RRTE DURING EXPERIMENT 4 8 -HffJ *—I I—Q 85 SURFACE • MID Q BOTTOM A TRNK R CD 13 A A CD _ m is * o 6 . m — i 1 1 1 1 1 1 1 " i 1 1 1 — 0.0 e.O 16.0 ^,.JA.Olr, 32.0 40.0 48.0 , TIME IDRYS) TRNK B I o l—a QCCM. CL U J . C C A _ A A CD e> 8 8 @ ° ° g H A T 1 1 1 1 1 1 1 1 1 — — r 0.0 6.0 16.0 ,TlirZ4.Ci „ 32.0 40.0 48.0 TIME (DRYS) 197 FIGURE W NET PRIMARY PRODUCTIVITY DURING EXPERIMENT 4 SURFACE Q MIC Q BOTTOM A CDcV C3 TRNK R ^ . a I * a • f T 1 1 1 1 1 1 r — — i 1——r " * - ° i S " ° T J M E 2 4 ( D R Y S ) 3 2 - 0 m ' Q 4 8 0 TRNK B U J A B I B ! H 1 ^ | m o " S S T ^ 1 1 —1 1 I 1 1 1 1 1 1 1 •J 8.o ,e.o n H ^ f t f i Y S ) „.„ m j t 198 FIGURE 5 0 NET"PRIMARY PRODUCTIVITY (DRILY) DURING EXPERIMENT 4 SURFACE A HID © BOTTOM _ o TRNK R LL) CJD 0 1 ' LU Q V" >-CE UJ CC Cu CL -4 UJ — A CD A | A t I © S A ffl a 8 O CD ^ A H — r 1 1 1 1 r — i 1 1 1 1 — . 6 . 0 T 3 H E ^ 0 D f l Y S ) 32.0 4 1 . 0 43.0 TRNK B j fi a 5 » § a S m _  * u m —| 1 1 1 1 1 1 n 1 1 1 — 0.0 fi.O 16.0 _.._24.0 _ 32.0 40.0 48.0 •JHfcTftflYS) 199 FIGURE 5 \ GROSS PRIMRRY PRODUCTIVITY (DRILY) DURING EXPERIMENT 4 cc CL. cn-' SURFACE Q HJO Q BOTTOM A TRNK R A 01 A S A B A A a-© o GJ • S A CD (D (D GJ 8 CD . * A s — I r 1 1 n 1 r — — r 1 1 1 1 1 i6.o T ] M ^ A f ) Y S ) *.o <o.o «.o a UJtr)' U T CL. cn a cc . CD o o" TRNK B C3 & CD ft Q ^ * CJ * CD A ^ A A • CD CD B ° 0 O G) GJ A 1——I 1 1 1 1 1 1 1 1 1 1 ' 6 - ° T J M E ^ R Y S ) * - 3 * • * 200 FIGURE 5 2 GROSS PRIMRRY PRODUCTIVITY (STRNDRRDIZED) DURING EXPERIMENT 4 SURFACE GJ HID Q B0T1OH A « TRNK R CM CC • X x -o CD . Z3 \ ZD c i - q cc H CJD o o © _ a A • e © o A G3 _ _ A -i 1 1 1 1 i 1 r 1 1 1 1 — 0.0 8.0 1S.0 ^ ^ . 0 ^ ^ 32.0 43.0 43.0 TRNK B cc • _J<D. CJ C3 . ZD _ CO CD § H CD A ° B m O m © a © _ A A & © CD a o a A 1 1 1 1 1 1 1 1 1 1 1 1 1 B ' ° 7i«?Ams> 4 U 201 FIGURE S 3 NET PRIMARY PRODUCTIVITY (STRNDRRDIZED) DURING EXPERIMENT 4 SURFACE Q HID QJ o TRNK R C M CC x Q x C J CD ClgfJ 3 O L I— UJ A ^ 9 6 | B I 5 I — i r 1 1 1 1 1 1 1 1 1 1 — M - I M T I | c « f t B Y S ) * . « «• • • « • « TRNK B EC CEflO. X o CD CD" Z3 Cu o »— UJ ZZ • Ala 8 8 $ B & — i 1 1 1 1 1 1 — n 1 1 1 1 — U J . 1 J f E « f t R Y S ) 202 FIGURE-54 RESPIRRTIQN RATE (STRNDRRDIZEDJ DURING EXPERIMENT 4 SURFACE a HID o B0T1OH A 9 TRNK R CM cc _ C J 3 U J m m & -J _ A 8 A A B A A 8 A CD GJ r 1 1 1 1 1 1 1 1 1 r i8.o T ] M E*YD f l Y S ) »•«» -.o « cc X V . C E O x - ; M CJ CD =1 1 •v. Oo C D ™ _  CE op CL cn . UJ cc TRNK B A A A 8 "I 1 1 1 1 1 r— A—i 1 1 — — r FIGURE 55 203 ESTIMATES OF ALPHAC DURING EXPERIMENT A SURFACE E MID © BOTIOM A cn x v, • CJ V . -CJ 2 8 -u cc . a. TRNK R A T 8 - A n ' l 0 TIH^ftflYSJ ^ 0.0 a.o T 40.0 43.0 CC X 5-CD V . . CJ C D 0 . 3s-CJ ex . X D_ cro. o 0.0 TRNK B i — 8.0 ft, A 16.3 @ TIME ftRYS). • i 32.0 43.0 43.0 204 FIGURE 5 4 ESTIMATES OF ALPHAG DURING EXPERIMENT A SURFACE Q MID o J8-v . " cc IT v. • X Qu cr-o TRNK R ® GI a © g A g A A m o 8 E O n> • g GJ — I r 1 1 1 1 1 1 1 1 1 — i — o . » . . . . 6 . 0 m i ^ m S i * . » « '— cr x \ • cc Z J ° . o§-CD Z3 v. . u CD°. CD <X J X H D_ fife A 8 CD A © © GJ Q GJ TRNK B A © © £ 7E0.0 © a A © m — i — 6 .0 0.0 '6-° T I M E R S ) 33-° 40.0 I — 4 3 . 0 Figure 57. Coulter counts on Day 6 of Experiment 4A Figure 59. Coulter counts on Day 15 of Experiment 4A COULTER COUNTS 417 15 SURFRCE— MID _ _ _ BOTTOM- _ Figure 61. Coulter counts on Day 27 of Experiment 4 A COULTER COUNTS 417 27 FIGURE 6 1 FORCING CONDITIONS DURING EXPERIMENT 5 211 FIGURE 43 INFLOW SURFRCE KID * TRNK R 8n o T r r 1 n 1 r-—i 1 r-—i 1 1 1 16.0 32.0 43.0 43.0 TEMPERATURE DURING EXPERIMENT 5 B8T10H OUTFLOW 212 FIGURE 64- NITRATE DURING EXPERIMENT 5 IHFLW SURFACE HID BOUGH OUTFLOW 213 FIGURE 65 PHYTOPLANKTON STOCK DURING EXPERIMENT 5 SURFACE BOUGH M I D . . . . . . . . . . . C U T f l C f l °. TRNK R S i cf 1 FIGURE U CHLB:CHLR RRT10 DURING EXPERIMENT 5 214 SURFACE HID WHOM OUTFLOV TRNK R 1 l~ 18.0 . 24.0 32.0 TIME IDRYS) 40.0 —I 43.0 TRNK B A r 16.0 „. 24.0 32.0 TIME IDRYS) • t j X l . 40.0 " 1 — 43.0 FIGURE LT CfiROTENOID:CHLfi RRTIO DURING EXPERIMENT 5 HID Barron OUTFLOtt TRNK R 8.0 0.0 - I 1 43.0 TRNK B i i 1 1 1 1 1 1 1 1 1 1 1 16.0 T l f E « . ( ° D f i r g ) SM «. 0 «.0 FIGURE 48 OXYGEN DURING EXPERIMENT 5 FIGURE Ll GROSS PRIMARY PRODUCTIVITY DURING EXPERIMENT 5 SURFACE [TJ FLUSHING RATES MID © O.JO 0.50 . amon A o.25 i.oo . 8_ T R N K R CD S ID CD D a- g o § CD e j o"T I I 1 1 1 1 1 1 r - 1 1 T L 6 - ° U I C ' V D R Y S ; * " 7RNK B a t » IS ' A E O m A GJ st * • © o GJ 8 Gl A o i T i r— 1 1 1 1 T f- 1 1 nr ,6.0 U ( 1 £Y D R V S ) »•» «•». 218 FIGURE 70 GROSS PRIMRRY PRODUCTIVITY (DAILY) DURING EXPERIMENT 5 e x C J ^ S U R F A C E a F L U S H I N G RATES MID o 0.10 0.50 , BOTTOM A 0.23 1.00 . TRNK R CD 8 H A CD B A Q A CD B I "I 1 i 1 1—; i 1 1 1 i — i 1 ,S.O «.» mM ca 93 TRNK B >-a cc cn~ cn Q 6 § ? 2 S » S * A CD A ro i ~r~ i i i i i 1 1 1 1 1 — a.o . 16J T J H E « f t f i Y S ) ».• « FIGURE 71 RESPIRRTION RRTE DURING EXPERIMENT 5 S U R F A C E N F L U S H I N G R A T E S HID © 0.10 0.50 . WTTOH A 0.25 1.00 . 2 _TRNK_ R_ W - - m 5 * m • © g fl ° . \ 0 O o i 1 1 i 1 1 1 1 1 1 r 3.0 16.0 ^Yn,^ *•» «•* ^  « TflNKB • * S . o B _ A x ®m ' ft ~ A * « D u ® a A fi A 8 ~ tp •21 H . * T I I i . — , — i * , i — , — " . 8-° 1 6-° TIHtTftflYS) 4 , - ° * - 0 220 FIGURE 72 NET PRIMARY PRODUCTIVITY DURING EXPERIMENT 5 SURFACE GJ FLUSHING RATES KID ffl 0.10 0.50 „ BOTTOM A 0.Z5 _ 1.00 cc° >M3 CScV i— UJ a o © CD © T R N K R 8 © T 1 1 1 1 1 1 1 1 1 r o.o mi<?ms} «•» «-» «•» TANK B UJ cc ">vO CD CM J 2 8 "M. Q . S I A D © © A ft © A m * Q A e a a A e ft g A I u a A FFL ^ g A a dT ®^ 1 1 1 1 1 1 1 1 1 1 1 0.0 6.0 16.0 „ 24.0 32.0 40.0 46.0 TIME IDflYS) 221 FIGURE 73 NET PRIMARY PRODUCTIVITY (DRILY) DURING EXPERIMENT 5 SURFRCE a FLUSHING FATES MID Q O.JO O.SO BOTICH A 0 . 2 3 1.00 TRNK R tu cc U J O A0J o 8 a 6 A GJ 1 1 1 1 1 1 1 1 1 1 1 1 1 8 . 0 16.0 7 J M F fY D R Y S ] 32 . 0 40 . 0 41 .0 TRNK B UJ CC UJ 2. o A 8 . GJ 0 A ,GJ ffl • * I Q ffi A E A ? « a . ffl s .. H m - s E @ GJ 1 1 1 J——I 1 1 1 1 1 1 1 0 . 0 e.o 1 6 . 0 ^ftflYS) 3 2 , 0 4 3 *° 222 FIGURE 7 4 GROSS PRIMARY PRODUCTIVITY (STANDARDIZED) DURING EXPERIMENT 5 SURFACE QJ MID © BOTTOM A RUSHINS RATES 0.10 0.50 . 0.23 1.00 . CC • • X X " o CD . ZO Z3 CD CO to A Gl B © © © © o TANK R — P — 8.0 fi © A © m A © © © til 0 1 A © E A T ^IHfcfftflYSl ^ ° 0.0 T T 40.0 43.0 cc • x C J CO . v . 3 CO CO Q 5 CO A © i m GJ i — 6.0 TRNK B s A O 8 © © 1 © 8 © © A CD fi H I 1 1——!~ 1 1 1 1 1 1 , 6-° TiNTftms) * J 0.0 2 2 3 FIGURE 7 5 RESPIRATION RATE tSTRNDRRDIZED) DURING EXPERIMENT 5 SURFACE GJ MID CO B o n c t f A FLUSHING RATES 0.10 0.50 . 0.25 1.00 . Q TT. CM CC J a a u aQ--l cc* M UJ ^ cc 0 03 A GI ffl @ TRNK R CD & £3 @ ® CD I — 8.0 o n H L ._ i i 1 1 1 r 1S.0 24,0 32.0 TIME iDRYSJ 0.0 43.0 43.0 cc J eta xH-C J CD Z 3 • CJ)CM. 3 " * CX .. 6-cj" E GJ O A m ~r e.o TRNK B Q a g o 9 a? 0.0 16.0 T T 43.0 T 43.0 224 FIGURE % 'NET'PRIMARY PRODUCTIVITY (STANDARDIZED) DURING EXPERIMENT 5 S U R F A C E n H I D © BOTTOM A FLUSHING RATES O . J O •'; 0.50 , 0.25 l . O D . a v . C M CC I T 0 3 - J - * X C J CD 9 ° < J e J . CD ZD Cu o U J a a © a, m A © 'a © © TANK A A a A m 0 a ~ ~ i — 1S.0 0.0 8.0 40.0 48.0 5** XX txajJ o CD " C J w . CUtD" UJ 2 A © A* © © 3 © TANK B © S A A g A (fi © 0.0 e.o 16.0 1 1 1 1 — „ 24.0 32.0 TIME (DAYS) 40.0 49.0 225 FIGURE 77 ESTIMATES GF RLPHAC DURING EXPERIMENT 5 SURFACE E MID ffl FLUSHING RATES 0.10 . 0.50 . 0.23 1.00 , 9 X 5 § J CO a 1 3sH C J cr. a TRNK R GjCD 1 1 r ,0 8.0 - i 1 1—"i r 16.0 43.0 48.0 X 55-C9 C J co°. 38" o £ • cu a k 'A 03 TRNK B A i S N g i g ffl A CD ffi 0.0 6.0 16.0 24.0 32.0 T I M E I D R Y S ) i r 40.0 48.0 226 FIGURE 78 ESTIMATES OF ALPHAG DURING EXPERIMENT 5 SURFACE rrj FLUSHING RATES MID © 0.10 0.50 BOTTOM A 0.23 1.00 !;  9_ CC 5gJ C J & 1 CU Jh dg-l cc X 5°. C5 \ C J cs<=> , ES-i C D ah TRNK R CQ o A A A _ 0? CD A ^A Ag © m * CD & 0 . © A . 5 — I 1 1 1 1 1 "1 1 1 1 1 1 — S.O 18.0 T I M ^ L 0 3 R Y S J 32.0 43.0 43.0 TRNK B A A S A A A A A A 0 O A 0 A 0 A 0 0 0 0 0 0 0 0 0 A © — I 1 1 1 1 1 1 1 1 1 1 1 M 6.0 !S.O T ^ f t f i Y S ) 33.0 41.0 «.0 VOLUME PER ML (XlO" ) 0.0 100.0 200.0 300.0 430.0 500.0 600.0 700.0 800.0 900.0 1000.0 Figure 80. Coulter counts on Day 9 of Experiment 5A C O U L T E R C O U N T S 5 1 7 9 S U R F R C E MID BOTTOM. _ _ _ _ — i — —\— —i PARTICLE —I SIZE (M) ~ I — 18-o Figure 81. Coulter counts on Day 21 of Experiment 5A COULTER COUNTS 5 1 7 2 1 SURFRCE MID BOTTOM . _ _ Figure 82. Coulter counts on Day 24 of Experiment 5A COULTER COUNTS 517 24 S U R F R C E _ _ HID BOTTOM ___ Figure 83. Coulter counts on Day 36 of Experiment 5A COULTER COUNTS 517 36 SURFRCE : . MID BOTTOM-Figure 84. Coulter counts on Day 39 of Experiment 5A a a -COULTER COUNTS 517 39 SURFACE MID _ . _ . _ BOTTOM 2= a UJ S i / —\— 3 4 . I— I S .7 - r PARTICLE SIZE (A) 1 — \s.o 30.. b tsj co Figure 85. Coulter counts on Day 6 of Experiment 5B COULTER COUNTS 527 6 SURFACE MID _ _ _ BOTTOM : _ . 0 s -U J Q-UJ » . f i 7-» ii.a P A R T I C L E S I Z E ( x c ) l Y . o N 5 Figure 86. Coulter counts on Day 9 of Experiment 5B Figure 87. Coulter counts on Day 21 of Experiment 5B COULTER COUNTS 527 21 SURFACE MID _ . . . _ BOTTOM. 2=c c _ U J Figure 88. Coulter counts on Day 24 of Experiment 5B COULTER COUNTS 527 24 SURFRCE____ MID . . . . . . . BOTTOM cc"1 UJ Q. UJ i — i-fe ~1— *-7 — r - i 11.3-P A R T I C L E S I Z E C*t) 18-0 2Z-L 38. f N3 OJ 8 L U C L . L U > • s i Figure 89. Coulter counts on Day 36 of Experiment 5B a-8 COULTER COUNTS 527 36 SURFRCE MID _ BOTTOM —r 1 —I 1 — i-t, *.S 9,1 7.1 1 : r— 1 1 1 — — r — q.o 11.5 ;*.3 (S.e MJJT P A R T I C L E S I Z E NJ Figure 90. Coulter counts on Day 39 of Experiment 5B COULTER COUNTS 527 39 SURFACE MID BOTTOM FIGURE "11 TEMPERATURE IN TVQ-STRGE OYSTER CULTURES 239 WIN TANK ] TANK 2 TRNK 3 TANK 4 i CO UJ • -U J ° -i — ac cc -UJ Q. E X P E R I M E N T 1 o o — I 1 1 1 1 1 1 0.0 2.0 4.0 6.0 TIME tDRYS) ca 8-CJCVJ I C O U J a • U J Q . §2 -§ 3 -CXPER1MEIT I I o n 1 1 1 1 1——i 1 0.0 2.0 4.0 6.0 TIME (DRYS) E X P E R I M E N T I I I E X P E R I M E N T I V TIME tDRYS) FIGURE °iZ CHLOROPHYLL R IN TVD-STRGE OYSTER CULTURES 240 IHFLOV _ TRW I TAW 3 TRW 2 TRW 4 241 FIGURE <B OXYGEN LEVELS IN TVD-STRGE OYSTER CULTURES INFUW TANK 1 TANK Z TANK 3 TANK 4 q id. a EXPERIMENT I UJ CDo SO-L D -J. co fe a a' 0.0 2.0 i 1 1 — — r ~ TIME 4('8flYS) G ' ° a EXPERIMENT U-LU CC CD o a" 0.0 ~~i 1 1 1 r— 2.0 4.0 6.0 TIME (DAYS) a-. a EXPERIMENT m. UJ cc C D o UJ CO >-d ' 0.0 a cvi. UJ cc CDo UJ • t o >-EXPERIMENT IX 0.0 T 1 1 1——r 1 20 -— Mr- 60 TIME (flfWS) 242 Figure 94. Growth of oysters as a function of DENS in the two-stage culture ( DENS 1 (ggj DENS 2 DENS 3) *7 1 0 w O DC 0 4 . 0 U J Z EXP 1 EXP 2 EXP 3 EXP 4 5V S3 EXP 1 EXP 2 EXP 3 EXP 4 EXP1 EXP 2 EXP 3 EXP 4 EXP1 EXP 2 EXP 3 EXP 4 243 Figure 95. Growth of oysters as a function of SIZE i n the two-stage culture ( H| SIZE 1 fg| SIZE 2 E § SIZE 3 fx] SIZE 4) EXP1 E X P 2 E X P 3 EXP1 EXP 2 EXP 3 EXP 4 EXP1 E X P 2 E X P 3 E X P 4 § 20 I U J Q. j 10, 4.0 PS r-E X P i E X P2 E X P3 E X P4 EXP1 E X P 2 EXP3 EXP4 EXP1 E X P 2 EXP 3 E X P 4 244 Figure 96. The 'P versus I* curves as a function of temperature and nitrate conditions. cn x . CJ CD . rD \ u o 0 . Q 0.0 TEMPERATURES >+eC - -r- \ 8 ' 0 - A 0.1 NON- NUTRi E.NT UNITED. - 0 0 o & A 0 O B A • • O • A + + 9 T 1 r o.z. -1 1 1— 03 0.4 P A R C U - W I N * 1 1 ~i r~—r O o r • \ cr. C J CD . \ C J o C D « i ' Z3 €0 a. 0.0 N U T R I E N T U f V T f c D 0 A B 0.2. O a © A O 0.3 o.«f-A A EI a —i— Figure 97. Comparison of the simulated (PHYTO ) versus actual (PHAV) phytoplankton stock during Experiment 5B: Run 1 PHYTO MRX= 6 4 . 2 8 1 1 PHflV MRX= 5 4 . 1 7 5 TIME Figure 98. Comparison of the simulated (PHYTO ) versus a c t u a l (PHAV) phytoplankton stock during Experiment 5B: Run 2 PHYTO MRX= 5 9 . 1 8 8 3 PHRV MRX= 5 4 . 1 7 5 TIME Figure 99. Comparison of the simulated (PHYTO ) versus actual (PHAV) phytoplankton stock during Experiment 5B: Run 3 PHYTO MAX" 6 9 . 1 5 4 6 PHflV MRX= 5 4 . 1 7 5 TIME NS Figure 100. Comparison of the simulated (PHYT0——) versus actual (PHAV) phytoplankton stock during Experiment 5B: Run 4 PHYTO M f l X = . 7 9 . 0 8 8 6 PHflV MflX=. 5 4 . 1 7 5 TIME N3 00 Figure 101. Comparison of the simulated (PHYTO ) versus actual (PHAV) phytoplankton stock during Experiment 5A: Run 1 PHYTO MflX= 6 2 . 8 2 1 4 PHRV MAX= 4 5 . 5 7 5 TIME Figure 102. Comparison of the simulated during Experiment 5A: Run 2 (PHYTO—) versus actual (PHAV) phytoplankton stock PHYTO MflX= 4 4 . 6 4 8 7 PHRV MRX= 4 5 . 5 7 5 TIME NJ Oi O Figure 103. 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VII * EESCBIPT1CN * UNITS * DEBIMTICls ***** 4**4*+;**** ******* IX E EXPERIMENT 1 TIME ' £ AY TIXED SAMPLING T (0830 H B EST) Z DEPTH STN STATION (INFL0H,OUT- METBE FIXED LOCATION' FLOR, S,M,E DEETHS) SUESTN SUBSTATION FIXED A B E A I IOC. v FLOW B A T E LITBE/DAY MEASUBEC V VOLUME L I T B E C A I C U I A T I E FB FLUSHING BATE PEE DAY v/V SINK SINKING BATE M/EAY M E l S USEE S i INCITENT LANCLEY/DAY ME A SU BED SOLAB BABXATICN (LY/DY) IA B PHOTOSYNTHETICALLY IANGLEY/DAY 0.50*SB A V M L A I L E BADIAT * N (LY/DY) E ABO PAH BUSING 02 LANGLEY/4 HB MEASUBEE INCUB*N PEBIOD (LY/INCUB) IABC PAS CUBING C14 LANGIEY/4 HE MEASUBEC INCUE'N PEBIOD (LY/INCUB) E X T K EXTINCTION COEFF. PEB METBE .04*. GC88CHLA + .054 (CHLA**.6667) EABAV BAB AT DEPTB LANGLEY/MIN P A K E X P J-EXTK*Z) PABZO PAB AT DEPTH FOB LAEGLEY/MIN (. 5*EA10/24G.) * 02 INCUE'N PEBIOD (LY/MIN) EXP (-EXTK*Z) PABZC PAB AT DEPTH FOB XAKGLEY/MIN (.5*PABC/2 4 0 . ) * C14 INCUB'N PEBIOD (LY/MIN) EXP (-EXTK*Z) SAL S A L I N I T Y PPT (0/00) ME ASUBED TEMP TEMPEEATUBE DEGBEES C. (DEG-C) MEASUBEC TIME N NET TEMPEEATUBE DEG-C., TEME (Z)-TEKE (I) N03 { N I T E A T E ] UM N03-N/LITBE MEASUBEC JSC3N NET [ N I T B A T E ] UM N03-N/LITBE N03 ( I ) - N 0 3 (Z) K B 3 [AMMONIA] UM NH3-N/LITBE MEASUBEC OBEA £ USEA ] UM UEEA-N/IITBE MEASUBEC EC 4 £ PHOSPHATE] UM PG4-P/LITBE ME ASUSE D S I 0 3 £ S I L I C A T E ] UM S I G 3 - S I / L I I B E MEASUBEC OXY [OXYGEN ] MG 0 2 / L I T B E ME ASUBED OXYN NET £ OXYGEN ] MG 0 2 / L I T B E OXY ( I ) - O X Y i ( Z ) SAT OXYGEN SATUSATION PEBCENT (%) OXY/SOLUBIIITY CHLA £CHLOEOPHYLL a] UG CHLA/LITBE MEASUBEC CfiLB £ CHLOEOPHYLL b] UG C E 1 E / L I T E E MEASUBEC CHLC £CHLOEOPHYLL c] UG C E L C / L I T B E MEASUBEC C I 1CAB0TEN0IDS] UG C T / L I T E E MEASUBEC EA BATIO CHLB TO CELA DIMENSIONLESS CBI-E/CHL fi CA BATIO CHLC TO CHLA DIMENSIONLESS CELC/C Hi A CTA BATIO CT TO CELA DIMENSIONLESS CT/CHLA EC BATIO CHLB TO CHLC DIHE NSIGNLESS C E L E / C E L C ECT BATIO CBLB TO CT DIMENSIONLESS C E I B / CT CCT BATIO CHLC TO CT DIMENSIONLESS . CE I C / CT :CHLA CAEBGN/CHLA DIMENSIONLESS CABEC S/CHLA 26 1 EGG GEOSS EBOD. (02) UG C/LITBE/HB (UG 02/L/B £) /1.2 I NO NET EBOD, (02) UGC/LITBE/HE (EGO) - (BES) EES BESPIBATIGN UG C/LIT BE/HE (UG 02/L/BE)/1.0 EBOD NET PEOB. ,(C14) UG C/LITBE/HB MEASUEEDCJ HB) EXC EXUDATION (C14) UG C/LITBE/HB M EASUBED (4 HE) PGOST EGG (NORMALIZEE) UG C/UG CHLA/HE EGC/CBLA FNOST E NC(NO EM ALIZ ED) UG C/UG CHLA/HB ENG/CHLA BESST BES (NOEMA LIZEB) UG C/UG CHLA/fiE EES/CELA ASS PEOD (NOBM ALIZEE) UG C/UG CHLA/HB, EBOD/CHL fl EXCST EXC (NOB HA LIZ ED) UG C/UG C HI A/ HE EXC/CHLA EGGEY DAILY EGO MG C/LITBE/DY PGO* (SI/EAIC) *4. PCDY DAILY EBOD MG C/LITBE/DY EBOD* (SI/PAEC) *4. ALEE AG P.VS.I INIT.SLOPE UGC/UGCHLA/HE-LY/M EGG/CHL A/P AE ZO IX EH AC P.VS.I INIT.SLOPE UGC/UGCHLA/HB-LY/M EBOD/CEXA/E8BZC AEGO EBOD/PGO DIMENSIONS!ESS EECE/EGC EEGO BES/PGO DIMENSIONSLESS BES/FGC EPGO EXC/EGO DIMENSIONSLESS EXC/FGG ESTPGO ESTIMATED PGO DIMENSIONSLESS A P G 0 * E EG 0+11G 0 PMAX MAX. ASS UGC/UGCHLA/HB LSI ESTIMATE ETMAX MAX., PMAX UGC/UGCHL A/HB LSF ESTIMATE PHYI'O SIMULATED CHLA UG CHIA/LITBE SIMULATION EHAV AVEBAGE CELA UG CELA/LITEE MEASOBED P SIMULATED ASS UGC/UGCHLA/HB SIMULATION GIOWB SIMULATED GBOWTH PEE BAY SI MUXATIC K BATE GRAZE SIMULATED BATE PEB DAY SIMUIAIICN OF GBAZING 26; A1EENDIX 2. Description and derivation of addit i o n a l variables pertaining to hervivcre growth, VAE * DESCB1ETIGN * UNITS * DERIVATION 4 * * « * * 4 * 4 * * * < * * * * * * < * * * * * * * * * * * * * * * * * * * * 1 LENGTH « WIDTH D DEPTH WGTT TOTAL WEIGHT WGTM MEAT KEIGHT WGTS SfcILL WEIGHT NETL NET LENGTH NETS NET WIDTH NETD NET DEPTH KETIT NET TOTAL WEIGHT NET Hi! NET MEAT WEIGHT NETSS NET SHELL WEIGHT EE 11 % INCB. LENGTH PEEK % INCB. HIDTH IEBD 31 INCB. , DEPTH PEE ET % ISC8. WGTT EEiWM % INCB. KGTM EEEWS % INCB. WGTS GB KM NETJsM/WEEK GEHS N ETWS/fi f EK MSBATIO NETH.fi: NET8S ESUEV # SU1V1VCBS SIZE HERBIVOBE SIZE BESS HEREIVOEE DENSITY STKUP UPTAKE CCNC. OI PHYTOELANKTON STROPS UPTAKE BATE GE PHYTOPLANKTON CXYUP UPTAKE CONC. OF OXYGEN OXYDPR UPTAKE BATE OE OXYGEN Cfl CIS CM GRAMS GRAMS GRAMS c e CM CM GRAMS GJ3AHS GBAMS G/ZGO/WK G/ZOC/WK DIME NSIC NLESS NUMEEB N/A N/A UG CHI A/LIT EE UG CHLA/DAY MG 02/IITBE MG 02/IITBE EEASUSED MEASURED ME ASU.RI D MEASURED EEASUEED MEASURED I (f)-L U) s<f)-i<i) r (f)-E'ti) WGTT (f) -WGTT { i) WGTM (f) -SGTE'(i) WGTS (f) -WGTS (i) KETI/Ifi) NETW/W<i) NETD/D (i) NETM/WGTT (i) NETKM/fiGTM(i) NETWS/WGTS(i) CALCULATED CALCULATED CALCULATED Factor with U classes <1=£tallest;4=1erg est) Factor with 3 classes <1=lowest;3=highest) CHIA <I) -CHLA (C) STKUP*IB OXY (1) -CXY (C) CXYUP*IB 

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