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A morphological and biochemical comparison of articially and naturally-reared salmonids Ludwig, Bryan William 1980

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A MORPHOLOGICAL AND BIOCHEMICAL COMPARISON OF ARTIFICIALLY AND NATURALLY-REARED SALMONIDS  by  BRYAN WILLIAM LUDWIG B.Sc,  The U n i v e r s i t y o f B r i t i s h Columbia, 1977  A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in THE FACULTY OF GRADUATE STUDIES (Department o f Zoology)  We a c c e p t t h i s t h e s i s as c o n f o r m i n g to t h e r e q u i r e d s t a n d a r d  THE UNIVERSITY OF BRITISH COLUMBIA May 1980  B r y a n W i l l i a m Ludwig, 1980  '  In p r e s e n t i n g t h i s  thesis in partial  an a d v a n c e d d e g r e e a t the L i b r a r y I  further  for  shall  the U n i v e r s i t y  make i t  agree that  freely  this  thesis for  It  Department  f i n a n c i a l gain shall  of  The 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 W e s b r o o k P l a c e V a n c o u v e r , Canada V6T 1W5  „.*. Itffxc  B P 75-51 1 E  mo  I agree  r e f e r e n c e and copying of  this  that  not  copying or  for  that  study. thesis  by t h e Head o f my D e p a r t m e n t  i s understood  permission.  the requirements  B r i t i s h Columbia,  extensive  s c h o l a r l y p u r p o s e s may be g r a n t e d  written  DE-6  of  available for  permission for  by h i s r e p r e s e n t a t i v e s . of  f u l f i l m e n t of  or  publication  be a l l o w e d w i t h o u t  my  ii  ABSTRACT  W i l d salmonids survival.  a r e u s u a l l y s u p e r i o r t o h a t c h e r y salmonids  i n marine  I n t h i s s t u d y , comparisons were made between w i l d and  a r t i f i c i a l l y - r e a r e d coho salmon (Oncorhynchus k i s u t c h ) and s t e e l h e a d t r o u t (Salmo g a i r d n e r i ) t o i d e n t i f y m o r p h o l o g i c a l and b i o c h e m i c a l d i f f e r e n c e s and t h e causes o f these d i f f e r e n c e s . Coho salmon were o b t a i n e d from t h r e e types o f r e a r i n g f a c i l i t i e s : a hatchery production-channel, a semi-natural rearing-channel  (pool-riffle  sequence w i t h i n s e c t d r i f t ) b o t h a t t h e Qualicum r i v e r , and Burrows ponds at  the Capilano r i v e r .  Coho were f e d an Oregon M o i s t P e l l e t  diet.  S t e e l h e a d t r o u t , f e d a S i l v e r Cup d i e t , were r e a r e d i n l a k e net-pens (O'Connor l a k e ) .  W i l d f i s h were c a p t u r e d from t h e same watersheds i n  w h i c h t h e c u l t u r e d f i s h were r e a r e d . made a t v a r i o u s p e r i o d s i n t h e l i f e  F o r Qualicum coho, comparisons were history.  Coho s m o l t s , r e a r e d i n t h e p r o d u c t i o n - c h a n n e l  (11.8 cm, 17.5 g) and  Burrows ponds (12.4 cm, 18.4 g) were l o n g e r and h e a v i e r than w i l d coho from the Qualicum r i v e r (10.1 cm, 11.6 g) and C a p i l a n o r i v e r (11.1 cm, 14.6 g ) . Rearing-channel  s m o l t s (10.0 cm, 11.8 g) were s i m i l a r i n s i z e t o w i l d coho  from t h e Qualicum r i v e r .  C o n d i t i o n f a c t o r s were h i g h e r i n w i l d coho.  P r o d u c t i o n - c h a n n e l and Burrows pond s m o l t s were l o w e r i n m o i s t u r e (76.3%, 77.3% r e s p e c t i v e l y ) b u t h i g h e r i n l i p i d  (4.4%, 3.8%) than  w i l d c o u n t e r p a r t s (79.1%, 79.7% m o i s t u r e ; 3.0%, 2.0% l i p i d ) . few d i f f e r e n c e s i n ash o r p r o t e i n (% wet t i s s u e ) . i n a s h and p r o t e i n and lower i n l i p i d " ( %  their  There were  W i l d coho were h i g h e r  d r y t i s s u e ) b u t t h e r e were few  d i f f e r e n c e s when t h e d a t a were e x p r e s s e d as a p e r c e n t o f t h e l i p i d - f r e e d r y tissue.  Therefore, d i f f e r e n c e s i n proximate  c o m p o s i t i o n were c o n f i n e d t o  iii  m o i s t u r e and l i p i d .  P h o s p h o l i p i d c o n t e n t was s i m i l a r i n w i l d and  c u l t u r e d coho a v e r a g i n g 12.9 mg/g wet t i s s u e . In  coho, the g r e a t e s t d i f f e r e n c e s i n f a t t y a c i d c o m p o s i t i o n were i n  neutral l i p i d  (NL).  P r o d u c t i o n - c h a n n e l and r e a r i n g - c h a n n e l s m o l t s were  h i g h e r i n monounsaturates (58.2, 55.5% r e s p e c t i v e l y ) and u)6 f a t t y a c i d s (9.0, 7.5%) b u t were l o w e r i n u3 f a t t y a c i d s (12.7, 14.9%) than the w i l d coho (43.9% monounsaturates, 5.7% u)6 and 28.4% co3 f a t t y a c i d s ) . in polar l i p i d of  (PL) f a t t y a c i d s were s l i g h t .  Differences  I n w i l d coho, t h e NL c o n t e n t  18:2w6 (3.8%) was 0.6 times t h a t o f t h e p r o d u c t i o n  and r e a r i n g - c h a n n e l  coho w h i l e t h e 22:6w3 c o n t e n t (14.8%) was 2.2 times t h a t o f t h e p r o d u c t i o n and r e a r i n g - c h a n n e l coho. In  s t e e l h e a d , pen-reared and w i l d s m o l t s d i d n o t d i f f e r i n l e n g t h  (18.5 cm), w e i g h t  (62.4 g ) , c o n d i t i o n f a c t o r ( 4 . 6 2 ) , m o i s t u r e ( 7 6 . 4 % ) ,  ash ( 2 . 6 % ) , p r o t e i n (16.8%) and p h o s p h o l i p i d (9.2 mg/g wet t i s s u e ) . v a l u e s g i v e n a r e averages f o r p e n - r e a r e d and w i l d s m o l t s . s m o l t s (2.9%) were s i g n i f i c a n t l y lower i n l i p i d  The  Pen-reared  than t h e w i l d s t e e l h e a d  smolts (4.2%). F a t t y a c i d c o n t e n t o f p e n - r e a r e d and w i l d s t e e l h e a d d i f f e r e d i n b o t h n e u t r a l and p o l a r l i p i d .  P e n - r e a r e d s m o l t s had an co6 c o n t e n t o f 29.2% NL  and 10.0% PL and an 0)3 c o n t e n t o f 13.2% NL and 51.2% PL.  The w i l d  smolts  were lower i n w6 f a t t y a c i d s (4.9% NL, 3.5% PL) b u t were h i g h e r i n w3 f a t t y a c i d s (39.6% NL, 55.2% P L ) .  The c o n t e n t o f 22:6w3 (21.3%) i n n e u t r a l  l i p i d o f w i l d s m o l t s was 2.7 times l a r g e r than t h a t o f t h e p e n - r e a r e d smolts. The h i g h l i p i d c o n t e n t i n c u l t u r e d coho was a t t r i b u t e d t o t h e i r h i g h r a t i o n l e v e l and t h e h i g h e r l i p i d c o n t e n t i n Oregon M o i s t P e l l e t  (18.3%  iv  dry  •mWttoeV?) than i n a q u a t i c i n s e c t s (12.4% d r y t i s s u e ) ( P h i l l i p s e t a l .  1954).  The h i g h e r l i p i d c o n t e n t  i n w i l d s m o l t s may be a r e s u l t o f t h e i r  o l d e r age a t s m o l t i n g (2-3 y e a r s ) , a l t h o u g h a d e f i n i t i v e e x p l a n a t i o n i s n o t yet a v a i l a b l e .  D i f f e r e n c e s i n f a t t y a c i d c o m p o s i t i o n were due t o the d i e t .  Oregon M o i s t P e l l e t was much h i g h e r i n monounsaturates (58.9%) than a q u a t i c i n s e c t s ( P l e c o p t e r a , T r i c h o p t e r a , Ephemeroptera, Chironomidae) (40.7%).  S i l v e r Cup was much h i g h e r i n w6 f a t t y a c i d s (19.3%) than t h e  aquatic i n s e c t s (6.8%).  V  TABLE OF CONTENTS Page ABSTRACT.  i i  TABLE OF CONTENTS  v  LIST OF TABLES  viii  LIST OF FIGURES  ix  LIST OF APPENDIX TABLES  x i  ACKNOWLEDGMENTS  x i i  INTRODUCTION  1  Review o f F i s h L i p i d M e t a b o l i s m  2  MATERIALS AND METHODS. . I.  II.  III.  IV.  V. VI. VII. VIII.  Study Areas A. Qualicum R i v e r B. C a p i l a n o R i v e r C. Keogh R i v e r Rearing Conditions A. Qualicum Coho Salmon. 1. P r o d u c t i o n - c h a n n e l 2. R e a r i n g - c h a n n e l B. C a p i l a n o Coho Salmon. C. Keogh S t e e l h e a d T r o u t . F i e l d Sampling A. Qualicum R i v e r 1. P r o d u c t i o n - and R e a r i n g - c h a n n e l Coho 2. Qualicum R i v e r Coho 3. F i e l d P r o c e s s i n g o f Qualicum Coho 4. A q u a t i c I n s e c t s B. C a p i l a n o R i v e r C. Keogh R i v e r Proximate A n a l y s i s A. F i s h T i s s u e B. H a t c h e r y D i e t s C. A q u a t i c I n s e c t s Phospholipid Analysis Fatty Acid Analysis A. Methods B. C a l c u l a t i o n s . Data H a n d l i n g and S t a t i s t i c a l A n a l y s i s Fish Health  RESULTS I.  6  •  6 6 6 6 6 6 7 7 8 8 9 9 9 9 10 10 11 11 11 11 13 14 14 14 14 15 17 17 19  L e n g t h , Weight, and C o n d i t i o n , F a c t o r A. Coho Salmon from t h e Qualicum R i v e r . . . . . . .  19 19  vi  TABLE OF CONTENTS (cont'd) Page  II.  III. IV.  V.  B. Coho Salmon from t h e C a p i l a n o R i v e r . . . C. S t e e l h e a d T r o u t from t h e Keogh R i v e r . . . Proximate Composition A. Coho Salmon from t h e Qualicum R i v e r 1. P r e s m o l t s and Smolts 2. F r y and P a r r B. Coho Salmon from t h e C a p i l a n o R i v e r . C. S t e e l h e a d T r o u t from the Keogh R i v e r . . D. S e a s o n a l Changes i n Qualicum Coho... E. A q u a t i c I n s e c t s and H a t c h e r y D i e t s P h o s p h o l i p i d Content Fatty A c i d Composition A. I n d i v i d u a l F a t t y A c i d C o m p o s i t i o n 1. F i s h i. Coho Smolts from t h e Qualicum R i v e r . . . . ii. S t e e l h e a d Smolts from t h e Keogh R i v e r . . 2. A q u a t i c I n s e c t s and H a t c h e r y D i e t s 3. Comparison o f t h e D i e t and t h e F i s h Composition B. F a t t y A c i d C l a s s C o m p o s i t i o n 1. F i s h i. Coho Smolts from t h e Qualicum R i v e r . . . . ii. S t e e l h e a d Smolts from t h e Keogh R i v e r . . 2. A q u a t i c I n s e c t s and H a t c h e r y D i e t s 3. Comparison of t h e D i e t and the F i s h Composition Age o f t h e Smolts  DISCUSSION I.  II.  I n f l u e n c e o f R e a r i n g C o n d i t i o n s on Morphology and B i o c h e m i s t r y A. L e n g t h , Weight, and C o n d i t i o n . F a c t o r . . B. P r o x i m a t e C o m p o s i t i o n 1. Comparisons o f N a t u r a l l y and A r t i f i c i a l l y reared F i s h 2. S e a s o n a l Changes C. P h o s p h o l i p i d Content D. F a t t y A c i d Content Impact o f Smolt S i z e and B i o c h e m i c a l C o m p o s i t i o n on M a r i n e S u r v i v a l A. Smolt S i z e B. P r o x i m a t e C o m p o s i t i o n . . . C. F a t t y A c i d Content 1. E s s e n t i a l F a t t y A c i d s i n F i s h — 2. F a t t y A c i d Content and Membrane and L i p i d Function ••  20 20 20 20 20 21 22 22 22 23 24 24 24 24 24 26 26 27 27 28 28 28 29 29 30 31 31 31 32 32 36 37 38 40 40 41 41 42 43  vii  TABLE OF CONTENTS ( c o n t ' d ) Page 3. 4.  III.  Docosahexaenoic A c i d (22:6w3) F a t t y A c i d Requirements i n F r e s h and S a l t Water.. C o n c l u d i n g Remarks....  BIBLIOGRAPHY  44 45 46 48  viii  LIST OF TABLES Page Table 1  Table 2 Table 3  Table 4 Table 5  Table 6 Table 7 Table 8 Table 9 T a b l e 10 T a b l e 11 T a b l e 12  R e a r i n g c o n d i t i o n s i n t h e Qualicum, C a p i l a n o , and Keogh r i v e r s t u d y a r e a s  55  F o r k l e n g t h , wet w e i g h t and c o n d i t i o n f a c t o r o f coho salmon and s t e e l h e a d t r o u t  57  Whole body p r o x i m a t e c o m p o s i t i o n (% wet t i s s u e ) and p h o s p h o l i p i d c o n t e n t o f coho salmon and s t e e l h e a d trout  59  Whole body p r o x i m a t e c o m p o s i t i o n (% d r y t i s s u e ) o f coho salmon and s t e e l h e a d t r o u t  61  P r o x i m a t e c o m p o s i t i o n o f some a q u a t i c i n s e c t s (% wet t i s s u e ) and h a t c h e r y d i e t s (% wet t i s s u e and % d r y t i s s u e )  63  F a t t y a c i d c o m p o s i t i o n o f coho s m o l t s r e a r e d n a t u r a l l y i n t h e Qualicum r i v e r  65  F a t t y a c i d c o m p o s i t i o n o f coho s m o l t s r e a r e d i n a production-channel  67  F a t t y a c i d c o m p o s i t i o n o f coho s m o l t s r e a r e d i n a rearing-channel  69  F a t t y a c i d composition o f steelhead smolts r e a r e d n a t u r a l l y i n t h e Keogh r i v e r  71  F a t t y a c i d composition o f steelhead smolts reared i n net-pens  73  F a t t y a c i d c o m p o s i t i o n o f some a q u a t i c i n s e c t s and h a t c h e r y d i e t s  75  F a t t y a c i d c l a s s c o m p o s i t i o n (%) o f some a q u a t i c i n s e c t s and h a t c h e r y d i e t s  77  ix  LIST OF FIGURES Page Figure 1  Map of the s t u d y a r e a s showing the Keogh, Qualicum and C a p i l a n o r i v e r s .  79  Figure 2  Map of the Qualicum r i v e r system....  81  Figure 3  Map of the Keogh r i v e r system........  83  Figure 4  Map of the C a p i l a n o r i v e r system....  85  Figure 5  F o r k l e n g t h s of Qualicum coho salmon  87  Figure 6 .  Wet w e i g h t s of Qualicum coho salmon  89  Figure 7  C o n d i t i o n f a c t o r s o f Qualicum coho salmon  91  Figure 8  S e a s o n a l v a r i a t i o n s i n m o i s t u r e c o n t e n t of Qualicum coho salmon S e a s o n a l v a r i a t i o n s i n ash c o n t e n t o f Qualicum coho salmon  Figure 9 F i g u r e 10 F i g u r e 11 F i g u r e 12 F i g u r e 13 F i g u r e 14 F i g u r e 15 F i g u r e 16  93 95  Seasonal v a r i a t i o n s i n p r o t e i n content of Qualicum coho salmon.  97  Seasonal v a r i a t i o n s i n l i p i d content of Qualicum coho salmon  99  S a t u r a t e d f a t t y a c i d s i n coho salmon from the Qualicum r i v e r  101  Monounsaturated f a t t y a c i d s i n coho salmon from the Qualicum r i v e r . . .  103  P o l y u n s a t u r a t e d f a t t y a c i d s . i n coho salmon from the Qualicum r i v e r  105  F a t t y a c i d s of the co6 s e r i e s i n coho salmon from the Qualicum r i v e r  107  F a t t y a c i d s o f the CJ3 s e r i e s i n coho salmon from the Qualicum r i v e r  109  X  LIST OF FIGURES ( c o n t ' d ) Page F i g u r e 17  F i g u r e 18 F i g u r e 19  F i g u r e 20  F i g u r e 21 F i g u r e 22  R a t i o o f u6/co3 f a t t y a c i d s i n coho salmon from the Qualicum r i v e r , and s t e e l h e a d t r o u t from the Keogh r i v e r .  I l l  S a t u r a t e d f a t t y a c i d s i n s t e e l h e a d t r o u t from the Keogh r i v e r .  113  Monounsaturated f a t t y a c i d s i n s t e e l h e a d t r o u t from t h e Keogh r i v e r  115  Polyunsaturated f a t t y acids i n steelhead t r o u t from the Keogh r i v e r .  117  F a t t y a c i d s o f the w6 s e r i e s i n s t e e l h e a d t r o u t from t h e Keogh r i v e r .  119  F a t t y a c i d s o f t h e u3 s e r i e s i n s t e e l h e a d t r o u t from t h e Keogh r i v e r  121  xi  LIST OF APPENDIX TABLES Page Appendix t a b l e 1  Appendix t a b l e 2  Appendix t a b l e 3  Appendix t a b l e 4  P r o x i m a t e c o m p o s i t i o n (% d r y t i s s u e ) of n a t u r a l l y - r e a r e d coho salmon from t h e Qualicum r i v e r .  123  P r o x i m a t e c o m p o s i t i o n (•% d r y t i s s u e ) of p r o d u c t i o n - c h a n n e l coho salmon from t h e Qualicum r i v e r  125  P r o x i m a t e c o m p o s i t i o n (% d r y t i s s u e ) of r e a r i n g - c h a n n e l coho salmon from t h e Qualicum r i v e r .  127  Whole body p r o x i m a t e c o m p o s i t i o n (% l i p i d - f r e e d r y t i s s u e ) o f coho salmon and s t e e l h e a d t r o u t  129  xii  ACKNOWLEDGMENTS  Many persons have p r o v i d e d a s s i s t a n c e i n t h e development o f t h i s thesis.  I am g r a t e f u l t o Dr. W. S. Hoar f o r h i s generous support and  prompt and c o n s t r u c t i v e c r i t i c i s m o f e a r l i e r d r a f t s o f t h i s  thesis.  Drs. E. M. Donaldson, D. A. H i g g s , T. G. N o r t h c o t e , and A. F. Tautz a l s o p r o v i d e d u s e f u l comments on an e a r l i e r d r a f t .  W i t h p l e a s u r e I acknowledge  the t e c h n i c a l a i d s u p p l i e d by M. Skwarok, B. Dosanjh, H. Mahood, D. MacDonald, and t h e s t a f f a t the West Vancouver L a b o r a t o r y .  T h i s study  would n o t have been p o s s i b l e w i t h o u t t h e g e n e r o s i t y o f Dr. H. Mundie, D. H a r v i e , P. S l a n e y , and E. Stone i n a l l o w i n g a c c e s s t o t h e i r r e a r i n g f a c i l i t i e s and p r o v i d i n g f i e l d a s s i s t a n c e .  Laboratory f a c i l i t i e s  Vancouver L a b o r a t o r y ) were p r o v i d e d by Dr. E. M. Donaldson.  (West  I gratefully  acknowledge t h e a s s i s t a n c e o f H. M. Dye, and M. Young i n t h e p r e p a r a t i o n of  f i g u r e s and t a b l e s .  F i n a n c i a l support was g e n e r o u s l y s u p p l i e d by t h e  B r i t i s h Columbia F i s h and W i l d l i f e Branch; West Vancouver L a b o r a t o r y , Department o f F i s h e r i e s and Oceans; and g r a n t s - i n - a i d o f r e s e a r c h t o Dr. W. S. Hoar. With g r a t i t u d e , I d e d i c a t e t h i s t h e s i s t o my w i f e C a r o l f o r she endured more than I .  1  INTRODUCTION B r i t i s h Columbia i s c u r r e n t l y i n t h e m i d s t o f a s a l m o n i d enhancement program, t h e g o a l o f w h i c h i s t o double p r e s e n t l e v e l s o f s a l m o n i d s t o c k s . Much o f t h e emphasis o f t h i s program w i l l be p l a c e d on a r t i f i c i a l of  salmonids.  poor.  H i s t o r i c a l l y , t h e q u a l i t y o f t h e h a t c h e r y p r o d u c t has been  Over t h e p e r i o d 1937-1954, ocean s u r v i v a l o f coho salmon from  M i n t e r c r e e k , Washington, averaged 7.5%  rearing  (Gonsolus 1978).  3.5% w h i l e t h e w i l d coho s u r v i v a l was  More r e c e n t d a t a suggest t h a t the q u a l i t y o f t h e  h a t c h e r y p r o d u c t has n o t y e t improved.  A summary o f A t l a n t i c salmon  r e l e a s e s (1963-1969) f o r n o r t h e r n Europe, U.S.S.R., and N o r t h  America  r e v e a l e d t h a t t h e marine s u r v i v a l o f w i l d f i s h was 2.5 times t h a t o f t h e h a t c h e r y f i s h (Heland e t a l . 1972).  L o c a l l y , r e t u r n s o f h a t c h e r y coho t o  the Quinsam r i v e r , Vancouver I s l a n d , i n 1978 averaged coho r e t u r n s were 9.8% (D. MacQuarrie,  personal  5.4% w h i l e t h e w i l d  communication).  The reasons f o r poor marine s u r v i v a l i n c u l t u r e d salmonids a r e uncertain.  B i o c h e m i c a l c o m p o s i t i o n i s one o f s e v e r a l f a c t o r s  marine s u r v i v a l .  influencing  U n f o r t u n a t e l y , the o p t i m a l b i o c h e m i c a l c o m p o s i t i o n f o r  c u l t u r e d salmon has n o t been i d e n t i f i e d .  A composition s i m i l a r to w i l d  salmonids may be d e s i r a b l e i n c u l t u r e d salmon; however, few d e t a i l e d comparisons In  o f w i l d and c u l t u r e d P a c i f i c salmon have been made.  t h i s study, l e n g t h , weight, c o n d i t i o n f a c t o r , proximate  composition,  p h o s p h o l i p i d and f a t t y a c i d c o n t e n t o f w i l d and h a t c h e r y coho salmon and s t e e l h e a d t r o u t were compared.  The o b j e c t i v e s o f t h e p r o j e c t were t o  i d e n t i f y the m o r p h o l o g i c a l and b i o c h e m i c a l d i f f e r e n c e s i n w i l d and h a t c h e r y s a l m o n i d s , t h e s o u r c e o f these d i f f e r e n c e s i n t h e r e a r i n g e n v i r o n ment, and t o s p e c u l a t e on t h e i n f l u e n c e o f t h e m o r p h o l o g i c a l and b i o c h e m i c a l  2  d i f f e r e n c e s on marine s u r v i v a l .  To determine when d i f f e r e n c e s o c c u r r e d ,  comparisons o f coho salmon were made throughout t h e f r e s h w a t e r p o r t i o n of  the l i f e h i s t o r y .  Since the d i e t a f f e c t s the biochemical composition  of  f i s h , a comparison o f two h a t c h e r y d i e t s and some a q u a t i c i n s e c t s was  made. P r o x i m a t e c o m p o s i t i o n i n c l u d e s f o u r main t i s s u e components: ash,  p r o t e i n , and l i p i d .  p r o t e i n content.  moisture,  Only g r o s s measurements were made f o r a s h and  The e f f e c t s o f t h e s e two c o n s t i t u e n t s on s a l m o n i d marine  s u r v i v a l are considered i n the d i s c u s s i o n s e c t i o n .  S i n c e much o f t h i s  study i s concerned w i t h crude l i p i d and i t s components, f i s h  lipid  metabolism i s reviewed. Review o f F i s h L i p i d M e t a b o l i s m L i p i d m e t a b o l i s m i n f i s h i s p o o r l y understood b u t i s thought t o be s i m i l a r t o mammals.  D e t a i l s on mammalian l i p i d m e t a b o l i s m a r e based on  r e v i e w s by B e l l et. al_. (1976) and Harper e t a l .  (1979).  Where r e c o g n i z e d ,  d i f f e r e n c e s between f i s h and mammalian l i p i d m e t a b o l i s m a r e n o t e d . In mammals, most o f t h e l i p i d s a r e absorbed from t h e i n t e s t i n e as g m o n o a c y g l y c e r o l s and f a t t y a c i d s . the to  a p o s i t i o n on t h e a c y l g l y c e r o l s .  The d i g e s t i v e enzymes a r e s p e c i f i c f o r The absorbed l i p i d i s then s y n t h e s i z e d  t r i a c l y g l y c e r o l s and r e l e a s e d t o t h e lymph system as c h y l o m i c r o n s .  In  f i s h , a p o r t i o n o f t h e l i p i d may be c o m p l e t e l y h y d r o l y z e d t o f r e e f a t t y a c i d s b e f o r e a b s o r p t i o n (Cowey and Sargent 1979). the  method o f l i p i d a b s o r p t i o n .  F i s h may a l s o d i f f e r i n  Robinson and Mead (1973) proposed t h a t i n  f i s h , f a t t y a c i d s were absorbed by i n t e s t i n a l c e l l s , s y n t h e s i z e d t o t r i a c y l g l y c e r o l s , and r e l e a s e d t o t h e l a m i n a p r o p r i a .  Free f a t t y acids  3  were then absorbed from the l a m i n a p r o p r i a , t r a n s p o r t e d to the l i v e r v i a the  p o r t a l b l o o d , and s y n t h e s i z e d t o t r i a c y l g l y c e r o l s .  The  difference  i n the a b s o r b t i o n r o u t e between .... , . f i s h and mammals i s assumed t o be r e l a t e d t o the l a c k of a w e l l developed l a c t e a l system i n f i s h .  Absorp-  t i o n of f a t t y a c i d s d i r e c t l y from the i n t e s t i n e to the b l o o d , o r the mammalian system o f t r a n s p o r t o f t r i a c y l g l y c e r o l s by the lymph system t o the  b l o o d have not been d i s c o u n t e d i n f i s h A f t e r a b s o r p t i o n , f a t t y a c i d s can be:  utilized  (Cowey and Sargent 1979). t r a n s p o r t e d to storage depots,  f o r energy, c o n v e r t e d t o d i f f e r e n t f a t t y a c i d s by c h a i n e l o n g a t i o n  and d e s a t u r a t i o n , o r i n c o r p o r a t e d i n p h o s p h o l i p i d (Lee and Sinnhuber 1972). The r e g u l a t i o n of t h e s e pathways i s l a r g e l y unknown. In s a l m o n i d s , l i p i d i s s t o r e d i n r e d and w h i t e muscle, and m e s e n t e r i c s t o r a g e depots ( B i l i n s k i 1969; L i n e_t ad. 1977) .  Less a c t i v e species of  f i s h such as cod u t i l i z e the l i v e r as the p r i m a r y l i p i d s t o r a g e depot ( B i l i n s k i 1974). red  L i p i d depots i n w h i t e muscle a r e e x t r a c e l l u l a r w h i l e i n  muscle the depots a r e i n t r a c e l l u l a r and e x t r a c e l l u l a r (Cowey and  Sargent 1979).  Red muscle i s p r i m a r i l y f o r low-speed, s u s t a i n e d swimming,  and u t i l i z e s a e r o b i c m e t a b o l i s m of f a t as an energy s o u r c e .  White muscle  i s used f o r s h o r t b u r s t o r h i g h - s p e e d swimming and draws energy m a i n l y from a n a e r o b i c m e t a b o l i s m o f g l y c o g e n ( B i l i n s k i  1974).  L i p i d s a r e r e l e a s e d from depots i n t o the b l o o d i n the form of non-esterified fatty acids.  I n f i s h , t h e r e i s a p o s s i b i l i t y t h a t muscle  f a t r e s e r v e s can be u t i l i z e d  d i r e c t l y , w i t h o u t p a r t i c i p a t i o n of the b l o o d  stream (Cowey and Sargent 1979).  F a t r e l e a s e from s t o r a g e depots i s  i n h i b i t e d by i n c r e a s i n g d i e t a r y energy i n t a k e .  High concentrations of  adenosine d i p h o s p h a t e i n the t i s s u e s , o r hormones such as e p i n e p h r i n e ,  4  growth hormone, and and B u c k l e y lipid  t h y r o i d hormone, s t i m u l a t e f a t m o b i l i z a t i o n .  Castledine  (1979) i n v e s t i g a t e d the q u e s t i o n of m o b i l i z a t i o n o f n e u t r a l  f a t t y a c i d s f o r use i n p h o s p h o l i p i d .  Unfortunately,  their  e x p e r i m e n t s were i n c o n c l u s i v e as i n two o f the e i g h t cases t h e r e was evidence of m o b i l i z a t i o n .  As w i l l be d i s c u s s e d l a t e r , the q u e s t i o n  m o b i l i z a t i o n o f f a t t y a c i d s between l i p i d depots i s i m p o r t a n t ing  some  for  of determin-  the s i g n i f i c a n c e o f f a t t y a c i d d i f f e r e n c e s i n w i l d and h a t c h e r y F a t t y a c i d s a r e o x i d i z e d by b e t a o x i d a t i o n , as i n mammals.  takes place i n mitochondria acids across  fish.  Oxidation  and r e q u i r e s c a r n i t i n e f o r t r a n s f e r o f  fatty  the i n n e r m i t o c h o n d r i a l membrane ( D r i e d z i c and Hochachka 1978).  Red muscle has a g r e a t e r c a p a c i t y to o x i d i z e f a t t y a c i d s than w h i t e  muscle  ( B i l i n s k i 1969). I n coho salmon, f a t t y a c i d s a r e s y n t h e s i z e d p r i m a r i l y by the ( L i n _et a l . 1977) .  liver  An e x t r a m i t o c h o n d r i a l system f o r de novo s y n t h e s i s o f  p a l m i t a t e from a c e t y l Co-A  has been found i n many t i s s u e s .  As w e l l ,  there  a r e systems f o r c h a i n e l o n g a t i o n and d e s a t u r a t i o n i n b o t h m i t o c h o n d r i a microsomes.  F i s h a r e not a b l e to s y n t h e s i z e f a t t y a c i d s o f the  ( l i n o l e n i c ) o r CJ6 ( l i n o l e i c ) s e r i e s . i s e x p l a i n e d w i t h an example:  The  and  u3  system f o r f a t t y a c i d nomenclature  18:2co6 where 18 i s the t o t a l number of  carbons i n the c h a i n , 2 i s the t o t a l number o f d o u b l e bonds, and w6  i s the  number o f c a r b o n s , c o u n t i n g  the  f i r s t d o u b l e bond.  from the m e t h y l end,  to the p o s i t i o n o f  F a t t y a c i d s o f the w3 and co6 s e r i e s , once gained  the d i e t , can be a l t e r e d by c h a i n e l o n g a t i o n and d e s a t u r a t i o n . p o i n t f o r e l o n g a t i o n and  end  d e s a t u r a t i o n of to3 f a t t y a c i d s i n f i s h i s 22:6w3,  w h i l e f o r a)6 f a t t y a c i d s , the end p o i n t i s 22:5OJ6. of u n s a t u r a t i o n i s gained  The  from  Thus, a g r e a t e r degree  from the ix>3 c o n f i g u r a t i o n .  5  F a t t y a c i d s o f t h e w3, u)6, and u9 s e r i e s compete f o r enzyme s i t e s f o r e l o n g a t i o n and d e s a t u r a t i o n .  The to3 f a t t y a c i d s have t h e g r e a t e s t  a f f i n i t y f o r enzyme s i t e s , and t h e u)9 f a t t y a c i d s t h e l e a s t (Lee and Sinnhuber 1972). L i t t l e i s known on t h e c o n t r o l o f f a t t y a c i d s y n t h e s i s , a l t h o u g h a g a i n , d i e t has some i n f l u e n c e .  F a t t y a c i d s y n t h e s i s i s i n h i b i t e d when the  d i e t a r y i n t a k e o f l i p i d i s h i g h o r when energy i n t a k e i s r e s t r i c t e d .  6  MATERIALS AND METHODS  I.  Study Areas A.  Qualicum R i v e r  T h i s r i v e r i s l o c a t e d on the e a s t s i d e o f Vancouver I s l a n d ( F i g . 1,2). R i v e r f l o w i s c o n t r o l l e d by a gate a t the o u t l e t o f H o m e l a k e .  The  p h y s i c a l f e a t u r e s o f the r i v e r and d e t a i l s on f l o w c o n t r o l have been d e s c r i b e d by L i s t e r and Walker (1966).  F i s h p r o d u c t i o n i n the r i v e r i s  augmented by a h a t c h e r y f a c i l i t y w h i c h i n c l u d e s a p r o d u c t i o n - c h a n n e l  and an  e x p e r i m e n t a l r e a r i n g - c h a n n e l f o r coho. B.  Capilano River  Located  i n N o r t h Vancouver, B. C , t h i s 29 km l o n g r i v e r d r a i n s i n t o  Burrard I n l e t .  A dam l o c a t e d 6 km from the mouth o f the r i v e r marks t h e  upper l i m i t o f f i s h a c c e s s .  A hatchery  facility  i s l o c a t e d 0.5 km  downstream from the dam. C.  Keogh R i v e r  T h i s 30 km r i v e r d r a i n s i n t o Queen C h a r l o t t e S t r a i t ( F i g . 1,3).  The  p h y s i c a l f e a t u r e s o f the r i v e r have been d e s c r i b e d by Ward and Slaney The r i v e r s u p p o r t s a n a t u r a l run o f s t e e l h e a d .  (1979).  As w e l l , s t e e l h e a d a r e  r a i s e d i n net-pens l o c a t e d on O'Connor l a k e . II.  Rearing A.  Conditions  Qualicum Coho Salmon  Coho salmon were r a i s e d i n a p r o d u c t i o n - c h a n n e l  and a r e a r i n g - c h a n n e l  by employees o f the Department o f F i s h e r i e s and Oceans.  Egg sources f o r  these salmon were a d u l t coho t h a t had r e t u r n e d t o t h e r i v e r system i n t h e f a l l o f 1977.  A d u l t coho n o t trapped by a c o u n t i n g fence a t the  hatchery  7  were a l l o w e d to spawn n a t u r a l l y i n the r i v e r . i n Heath t r a y s u n t i l h a t c h i n g . production 1.  Coho eggs were i n c u b a t e d  These f r y were then used to s t o c k the  and the . r e a r i n g - c h a n n e l s . Production-channel  Coho salmon were r e a r e d i n a g r a v e l bottom channel l o c a t e d 1.2 the r i v e r mouth ( F i g . 2 ) . J u l y , 1978)  i n a c o n c r e t e pond and then moved to the  F i s h were f e d d a i l y w i t h Oregon M o i s t P e l l e t . to A p r i l ) f e e d i n g f r e q u e n c y was  production-channel May).  D u r i n g the w i n t e r (December  reduced depending on f i s h  activity.  Rearing-channel  The r e a r i n g - c h a n n e l was The  from  Coho f r y were r a i s e d f o r t h r e e months ( A p r i l to  (750,000 f r y ) . Coho remained i n the channel u n t i l s m o l t i n g ( l a t e  2.  km  c h a n n e l was  l o c a t e d 4.5  km from the r i v e r mouth ( F i g . 2 ) .  c o n s t r u c t e d w i t h p o o l s and r i f f l e s d e s i g n e d  p h y s i c a l f e a t u r e s of a n a t u r a l stream.  to mimic the  Plywood f l o a t s were anchored i n the  p o o l s t o p r o v i d e cover f o r the coho.  The channel was  by n e t t i n g t o reduce b i r d p r e d a t i o n .  P h y s i c a l f e a t u r e s o f the channel  f u r t h e r d e s c r i b e d by Mundie and Mounce (1978). i n t o the channel  i n l a t e A p r i l , 1978  s m o l t i n g i n June, 1979.  completely  covered are  Coho f r y were i n t r o d u c e d  and remained i n the f a c i l i t y  until  F i s h were f e d Oregon M o i s t P e l l e t every o t h e r  day.  P e l l e t s were i n t r o d u c e d t o the tops o f the p o o l s and a l l o w e d to d r i f t throughout the p o o l .  I t was  hoped t h a t on days when p e l l e t s were not  o f f e r e d , the f i s h would f e e d on i n v e r t e b r a t e d r i f t and benthos produced i n the channel r i f f l e s .  P e l l e t s were f e d l e s s f r e q u e n t l y d u r i n g the w i n t e r  depending on f i s h a c t i v i t y .  F i s h movement up and down the channel  r e s t r i c t e d by aluminum f e n c e s t o i n s u r e e f f i c i e n t usage o f the  was  channel.  8  B.  C a p i l a n o Coho Salmon  Coho were r e a r e d i n Burrows ponds by employees o f the Department of F i s h e r i e s and Oceans.  Eggs were t a k e n from a d u l t coho t h a t had r e t u r n e d  to the r i v e r i n t h e f a l l o f 1977.  Eggs were i n c u b a t e d i n Heath  trays.  Coho were moved to t h e Burrows ponds as f r y arid r e a r e d u n t i l s m o l t i n g (June, 1979) on a d i e t o f Oregon M o i s t P e l l e t . C.  Keogh S t e e l h e a d T r o u t  S t e e l h e a d were r a i s e d i n net-pens by employees o f t h e F i s h and W i l d l i f e Branch.  Nets were hung from f l o a t s and anchored t o the bottom o f  O'Connor l a k e ( F i g . 3 ) . Net mesh s i z e v a r i e d from 0.6 t o 1.0 cm depending on f i s h s i z e .  Eggs were t a k e n from a d u l t s t r a p p e d a t the mouth o f t h e  Keogh r i v e r (March, 1978) and i n c u b a t e d i n wooden t r o u g h s . t r a n s f e r r e d t o t h e pens by August, 1978. Cup, a d r y d i e t .  P a r r were  F i s h were f e d d a i l y w i t h S i l v e r  F i s h a l s o had t h e o p p o r t u n i t y t o f e e d on z o o p l a n k t o n  produced i n t h e l a k e , a l t h o u g h no measure o f t h e amount o f z o o p l a n k t o n e a t e n was a v a i l a b l e .  Smolts were r e l e a s e d a t the mouth o f the r i v e r (May,  1979) a f t e r t r a n s p o r t by tank t r u c k . R e a r i n g c o n d i t i o n s i n the t h r e e s t u d y a r e a s a r e f u r t h e r d e s c r i b e d i n T a b l e 1.  R e a r i n g a r e a s were s i m i l a r i n mean a n n u a l water temperature b u t  d i f f e r e d i n water v e l o c i t y and f i s h d e n s i t y .  Burrows ponds had t h e l o w e s t  water v e l o c i t y b u t t h e h i g h e s t f i s h d e n s i t y . . Water temperatures were n o t measured i n the Qualicum r i v e r .  The r e a r i n g - c h a n n e l water temperature would  be a c l o s e e s t i m a t e o f t h e water temperature a t the t h r e e sample s t a t i o n s i n t h e Qualicum r i v e r .  9  III.  F i e l d Sampling A.  Qualicum R i v e r 1.  P r o d u c t i o n and R e a r i n g - c h a n n e l Coho  Coho were sampled as f r y ( A p r i l , 1978), p a r r (August, 1978; J a n u a r y , 1979), p r e s m o l t s ( A p r i l , 1979), and s m o l t s (May, 1979). t h a t had r e c e n t l y emerged from the g r a v e l . b a r s of dark pigment  F r y were f i s h  P a r r demonstrated  prominent  ( p a r r marks) e x t e n d i n g above and below the l a t e r a l  l i n e and were p h y s i o l o g i c a l l y adapted f o r l i f e i n f r e s h w a t e r .  Presmolts  had begun t h e p a r r - s m o l t t r a n s f o r m a t i o n (some s i l v e r c o l o r a t i o n ) but showed prominent p a r r marks.  Smolts demonstrated the t y p i c a l  still  silver  c o l o r a t i o n (guanine d e p o s i t i o n ) w i t h dark f i n t i p s and were p h y s i o l o g i c a l l y adapted f o r l i f e i n sea w a t e r .  Each sample c o n s i s t e d o f f i s h t a k e n from  p o i n t s a l o n g t h e e n t i r e l e n g t h s o f the r e s p e c t i v e c h a n n e l s .  F i s h were  c a p t u r e d w i t h a d i p n e t , t r a n s p o r t e d l i v e t o the l a b o r a t o r y a t the main h a t c h e r y , and h e l d t h e r e u n t i l w e i g h i n g .  Sample s i z e v a r i e d w i t h the  w e i g h t o f the f i s h . 2.  Qualicum R i v e r Coho  Coho were c o l l e c t e d monthly o v e r the p e r i o d May, S e v e r a l sample s t a t i o n s were u t i l i z e d .  1978 t o May,  1979.  S t a t i o n number 1, l o c a t e d 7.8  km  from the r i v e r mouth ( F i g . 2 ) , was dominated by a l a r g e l o g jam w h i c h c r e a t e d 1.0 m t o 3.0 m deep p o o l s . and c u t b a n k s . (Fig.  2).  E x t e n s i v e cover was p r o v i d e d by l o g s  S t a t i o n number 2 was l o c a t e d 3.8 km from the r i v e r mouth  T h i s s t a t i o n c o n s i s t e d o f a s i n g l e l o g , r u n n i n g p a r a l l e l t o the  r i v e r bank, c r e a t i n g a 0.5 m deep p o o l . the  S t a t i o n number 3 was l o c a t e d i n  main r i v e r a d j a c e n t t o the r e a r i n g c h a n n e l ( F i g . 2 ) .  I t c o n s i s t e d of  a 100.0 m l o n g s t r e t c h o f cutbanks and o v e r h a n g i n g v e g e t a t i o n a l o n g b o t h  10  s i d e s o f the r i v e r .  Samples f o r the months o f May  were c o l l e c t e d from s t a t i o n 1 and 2.  to September,  S t a t i o n 2 was n o t u t i l i z e d  October, 1978 due t o an i n c r e a s e i n r i v e r f l o w .  1978 after  The October, 1978  to  J a n u a r y , 1979 samples were made up o f f i s h caught p r i m a r i l y a t s t a t i o n 1. Samples f o r the months o f February to A p r i l , 1979 were c o l l e c t e d a t s t a t i o n s 1 and  3.  F i s h were caught u s i n g a p o l e s e i n e and s c i s s o r s n e t , when p o s s i b l e . A f t e r December, 1978 f i s h began u t i l i z i n g heavy cover under l o g d e b r i s and cutbanks.  Nets were not s u i t a b l e i n t h i s type o f h a b i t a t and s a m p l i n g  completed by e l e c t r o s h o c k i n g .  Smolts were c o l l e c t e d by a n c h o r i n g a f y k e  n e t and l i v e box to the c o u n t i n g f e n c e a t the main h a t c h e r y (1.2 km the r i v e r mouth).  was  The n e t was  f i s h e d f o r 24 hours May  31, 1979.  from  F i s h were  t r a n s p o r t e d l i v e t o the l a b o r a t o r y a t t h e h a t c h e r y f o r w e i g h i n g . 3.  F i e l d P r o c e s s i n g o f Qualicum Coho  I n d i v i d u a l w e i g h t s and f o r k l e n g t h s were r e c o r d e d a f t e r r o l l i n g the f i s h on an absorbant c l o t h .  P o o l e d samples of f i s h were then p l a c e d i n  p l a s t i c bags, i n f l a t e d w i t h n i t r o g e n gas, and s e a l e d . on dry i c e to the f i s h e r i e s l a b o r a t o r y , West Vancouver, were s t o r e d a t -27°C.  Samples were s h i p p e d B. C ,  where they  S c a l e s were t a k e n from n a t u r a l l y - r e a r e d s m o l t s f o r  aging. 4.  Aquatic Insects  I n s e c t s were c o l l e c t e d from the r e a r i n g - c h a n n e l u s i n g a Surber (212 ym mesh).  Samples were c o l l e c t e d i n A p r i l and June, 1979 from  a r e a s midway a l o n g t h e l e n g t h of the c h a n n e l .  sampler riffle  The P l e c o p t e r a sample was  c o l l e c t e d from the Qualicum r i v e r i n a r i f f l e a r e a a d j a c e n t to s t a t i o n 1. Samples were p l a c e d i n p l a s t i c bags, f i l l e d w i t h n i t r o g e n gas, and s h i p p e d  11  on d r y i c e t o t h e f i s h e r i e s l a b o r a t o r y i n West Vancouver. The samples were s t o r e d a t -27°C u n t i l B.  analysis.  Capilano R i v e r  H a t c h e r y coho s m o l t s were c o l l e c t e d June 5, 1979 j u s t p r i o r to t h e i r r e l e a s e from the h a t c h e r y .  The sample was c o l l e c t e d a f t e r the f i s h had  been c o n f i n e d i n t o a s m a l l a r e a o f t h e pond. June 1, 1979 as they m i g r a t e d downstream.  W i l d s m o l t s were caught  A f y k e n e t and l i v e box was  suspended i n t h e r i v e r a d j a c e n t t o t h e h a t c h e r y , and f i s h e d f o r 72 h o u r s . F i s h were weighed and measured a t t h e C a p i l a n o h a t c h e r y and p l a c e d i n p l a s t i c bags i n f l a t e d w i t h n i t r o g e n gas.  The f i s h were t r a n s p o r t e d , on i c e ,  to the f i s h e r i e s l a b o r a t o r y i n West Vancouver, B. C. and s t o r e d a t -27°C u n t i l analysis. C.  S c a l e s were t a k e n f o r a g i n g .  Keogh R i v e r  H a t c h e r y s t e e l h e a d s m o l t s were c o l l e c t e d May 10, 1979 j u s t p r i o r t o t h e i r r e l e a s e from the n e t pens.  W i l d s t e e l h e a d s m o l t s were c a p t u r e d  May 16 by a s a m p l i n g f e n c e l o c a t e d 200 m from the mouth o f t h e r i v e r .  Fish  were weighed and measured and then s h i p p e d f r o z e n t o t h e l a b o r a t o r y i n West Vancouver, B. C.  There t h e samples were s t o r e d a t -27°C u n t i l  analysis.  S c a l e s were c o l l e c t e d f o r a g i n g . IV.  Proximate A n a l y s i s A.  Fish Tissue  A minimum of 30 g o f f i s h t i s s u e was r e q u i r e d f o r p r o x i m a t e  analysis.  Depending on t h e i n d i v i d u a l f i s h w e i g h t s , 2-60 f i s h were p o o l e d f o r a n a l y s i s . A n a l y s i s i n a l l cases was on the whole body.  12  F i s h were homogenized i n a Waring b l e n d e r and weighed f r a c t i o n s removed f o r t o t a l n i t r o g e n , m o i s t u r e , a s h , and l i p i d d e t e r m i n a t i o n s . f o r t o t a l n i t r o g e n were wrapped i n w e i g h i n g  Samples  paper ( n i t r o g e n f r e e ) and s t o r e d  at -27°C u n t i l enough samples had accumulated t o p e r m i t e f f i c i e n t use o f the a u t o a n a l y s e r .  T o t a l n i t r o g e n was a n a l y s e d u s i n g t h e A.O.A.C. method  f o r crude p r o t e i n , as m o d i f i e d f o r a T e c h n i c o n a u t o a n a l y s e r  (A.O.A.C. 1975).  Samples were d i g e s t e d and a n a l y s e d u s i n g t h e T e c h n i c o n I n d u s t r i a l Method number 369-75 A/A and 334-74 w/B, r e s p e c t i v e l y . T o t a l n i t r o g e n was m u l t i p l i e d by 6.25 t o g i v e crude p r o t e i n c o n t e n t .  Samples f o r m o i s t u r e  d e t e r m i n a t i o n were d r i e d f o r 24 hours a t 105°C i n a g r a v i t y oven.  Samples  f o r a s h d e t e r m i n a t i o n were combusted f o r two hours a t 600°C i n a m u f f l e furnace.  L i p i d s were e x t r a c t e d u s i n g a m o d i f i c a t i o n o f t h e method o f B l i g h  and Dyer (1959).  Samples taken d u r i n g t h e p e r i o d May, 1978 t o March, 1979  were e x t r a c t e d i n t h e f o l l o w i n g manner: was blended  i n an omnimixer w i t h 10 ml o f c h l o r o f o r m and 20 ml o f methanol  f o r two m i n u t e s . 30 s.  A 20 g sample o f homogenized t i s s u e  Ten ml o f c h l o r o f o r m were added and blended  F i n a l l y , 9 ml o f d i s t i l l e d water were added and blended  a further f o r 30 s.  The homogenate was f i l t e r e d through Whatman Number 1 f i l t e r paper, on a Buchner f u n n e l .  The r e s i d u e was washed w i t h a s o l u t i o n o f 20 ml c h l o r o f o r m ,  20 ml methanol and 9 ml d i s t i l l e d w a t e r , and f i l t e r e d a g a i n . was then added t o t h e o r i g i n a l .  This  filtrate  The f i l t r a t e was poured i n t o a v o l u m e t r i c  f l a s k and a l l o w e d t o s e p a r a t e i n t o two l a y e r s .  The c a l c u l a t i o n o f p e r c e n t  crude l i p i d was based on a 3 ml a l i q u o t o f t h e c h l o r o f o r m l a y e r t h a t was taken to dryness. I n March, 1 9 7 9 , i t was noted t h a t t h i s m o d i f i c a t i o n was l e a v i n g 10-20% of t h e l i p i d i n t h e f i s h t i s s u e .  The B l i g h and Dyer method was a g a i n  13  m o d i f i e d i n t h e f o l l o w i n g manner.  A 20 g sample o f homogenated t i s s u e  was b l e n d e d w i t h 30 ml c h l o r o f o r m and 60 ml of methanol i n an for  two m i n u t e s .  omnimixer  T h i r t y ml of c h l o r o f o r m were added and b l e n d e d f o r 30 s.  Then, 25 ml o f d i s t i l l e d water were added and b l e n d e d f o r 30 s (B. Dosanjh, p e r s o n a l communication).  The homogenate was f i l t e r e d through Whatman  Number 1 f i l t e r paper on a Buchner  f u n n e l , and the p e r c e n t crude  lipid  d e t e r m i n a t i o n c a r r i e d out as p r e v i o u s l y d e s c r i b e d . T h i s m o d i f i c a t i o n performed w e l l when compared to the f i r s t B l i g h and Dyer method and the method of F o l c h et^ a l .  (1957), and was used on a l l o f the r e m a i n i n g samples.  A c o r r e c t i o n f a c t o r , c a l c u l a t e d by comparing the two m o d i f i c a t i o n s of t h e B l i g h and Dyer method to March,  was a p p l i e d to samples a n a l y s e d from May,  1978  1979.  L i p i d s were s t o r e d i n the f o l l o w i n g manner.  Butylated hydroxy-toluene  was added t o the l i p i d c h l o r o f o r m m i x t u r e ( 0 . 1 % of the w e i g h t o f l i p i d ) and then c e n t r i f u g e d f o r f i v e minutes a t 5000 RPM c e n t r i f u g e (-5°C).  i n a refrigerated  The l i p i d c h l o r o f o r m m i x t u r e was  s c i n t i l l a t i o n v i a l s and capped w i t h n i t r o g e n gas.  then poured  into  The v i a l s were p l a c e d i n  p l a s t i c bags, i n f l a t e d w i t h n i t r o g e n gas, and s t o r e d a t -45°C.  In a l l  c a s e s , l i p i d s were e x t r a c t e d from the f i s h and p l a c e d i n s t o r a g e no more than one day a f t e r f i e l d s a m p l i n g . B.  Hatchery D i e t s  D i e t s were a n a l y s e d u s i n g p r o c e d u r e s s i m i l a r t o the f i s h  samples.  The B l i g h and Dyer method was used to e x t r a c t l i p i d , w i t h the a p p r o p r i a t e m o d i f i c a t i o n s made t o a l l o w f o r the lower m o i s t u r e c o n t e n t i n h a t c h e r y d i e t s . V a r i a b i l i t y between d i e t b a t c h e s was n o t a f a c t o r i n t h i s s t u d y .  The  diet  b a t c h e s sampled were f e d to the f i s h f o r a t l e a s t seven months p r i o r t o smolting.  14  C.  Aquatic  Insects  Only crude l i p i d was d e t e r m i n e d on a q u a t i c i n s e c t s due t o t h e s m a l l amount o f t i s s u e a v a i l a b l e .  Samples were washed t h r o u g h a 600 ym mesh  s c r e e n and then q u i c k l y s o r t e d i n t o i n s e c t t y p e s .  The i n s e c t types  u t i l i z e d were Ephemeroptera (146 a n i m a l s ) , Chironomidae (337 a n i m a l s ) , T r i c h o p t e r a (45 a n i m a l s ) , and P l e c o p t e r a (4 a n i m a l s ) .  L i p i d s were  e x t r a c t e d u s i n g t h e method o f F o l c h e_t a l . (1957) and s t o r e d i n t h e same manner as f i s h  V.  lipid.  Phospholipid Analysis L i p i d s e x t r a c t e d from Qualicum coho p r e s m o l t s  s m o l t s , and Keogh s t e e l h e a d s m o l t s were a n a l y s e d u s i n g t h e method o f Raheja e t a l . (1973).  and s m o l t s , C a p i l a n o coho  f o rphospholipid  content  Phosphatidyl choline d i s t e a r o l y l  ( S e r d a r y R e s e a r c h L a b o r a t o r y , London, O n t a r i o ) was used as t h e p h o s p h o l i p i d standard.  Absorbance was measured a t 710 nm w i t h a G i l f o r d 2400 s p e c t r o -  photometer equipped w i t h a r e d f i l t e r .  P h o s p h o l i p i d c o n t e n t was  expressed  as a p e r c e n t o f t h e crude l i p i d , and as mg p h o s p h o l i p i d / g wet t i s s u e .  VI.  Fatty Acid Analysis A.  Methods  F a t t y a c i d a n a l y s e s were conducted on Qualicum coho s m o l t s , Keogh steelhead smolts  (four samples),  hatchery  d i e t s (one s a m p l e ) , and a q u a t i c  i n s e c t s (one sample). F i s h crude l i p i d ' w a s s e p a r a t e d  i n t o n e u t r a l and p o l a r l i p i d f r a c t i o n s  u s i n g s i l i c i c a c i d column chromatography. s u p p l i e d by M a l l i n c k r o d t I n c .  S i l i c i c a c i d ( S i l i c a r CC-7) was  G l a s s b a r r e l columns, 30 cm x 1 cm ( l . D . )  (Bio-Rad L a b o r a t o r i e s , M i s s i s s a u g a , O n t a r i o )  were used.  Neutral  lipids  15  were s e p a r a t e d u s i n g t e n column volumes o f c h l o r o f o r m , w h i l e p o l a r were  s e p a r a t e d u s i n g t e n column volumes o f methanol.  lipids  N e u t r a l and p o l a r  l i p i d f r a c t i o n s were checked f o r c r o s s - c o n t a m i n a t i o n u s i n g the method of Raheja et^ a l .  (1973) f o r p h o s p h o l i p i d s and the method of F o s t e r and Dunn  (1973) f o r t r i g l y c e r i d e s .  T r i o l e i n ( S e r d a r y Research L a b o r a t o r y , London,  O n t a r i o ) was used as the t r i g l y c e r i d e s t a n d a r d . F a t t y a c i d m e t h y l e s t e r s o f b o t h n e u t r a l and p o l a r l i p i d  fractions  were p r e p a r e d w i t h sodium methoxide as d e s c r i b e d by C h r i s t i e (1973).  Fatty  a c i d m e t h y l e s t e r s o f h a t c h e r y d i e t s and a q u a t i c i n s e c t s were p r e p a r e d d i r e c t l y from whole l i p i d w i t h sodium methoxide. F a t t y a c i d m e t h y l e s t e r s were s e p a r a t e d and q u a n t i f i e d u s i n g a H e w l e t t P a c k a r d model 5830A gas chromatograph equipped w i t h a flame i o n i z a tion detector.  A 3.2 m x  1.8 mm  s t a i n l e s s s t e e l column packed w i t h 10%  Sp 2330 on 100/120 chromosorb W. was used. (25 ml/min).  The c a r r i e r gas was  nitrogen  A l l r u n s were i s o t h e r m a l w i t h an oven temperature o f 175°C.  The i n j e c t i o n p o r t temperature was 220°C and the d e t e c t o r temperature was 270°C.  Peak a r e a s were c a l c u l a t e d a u t o m a t i c a l l y w i t h a H e w l e t t P a c k a r d  model 18850A m i c r o p r o c e s s o r .  F a t t y a c i d m e t h y l e s t e r s were i d e n t i f i e d by  comparing the r e l a t i v e r e t e n t i o n times w i t h f a t t y a c i d m e t h y l e s t e r s t a n d a r d s s u p p l i e d by S e r d a r y R e s e a r c h L a b o r a t o r y , London, O n t a r i o . Compounds f o r w h i c h s t a n d a r d s were n o t a v a i l a b l e were i d e n t i f i e d by s e m i l o g p l o t s o f carbon number v e r s u s r e l a t i v e r e t e n t i o n t i m e , or by s e p a r a t i o n f a c t o r s (Ackman, 1963). B.  Calculations  The c o n t e n t o f i n d i v i d u a l f a t t y a c i d s was e x p r e s s e d i n two ways: p e r c e n t o f t h e f a t t y a c i d s w h i c h chromatographed,  as a  and as mg f a t t y a c i d / g  16  wet  tissue.  required:  To make t h i s second c a l c u l a t i o n ,  two assumptions were  1) t h a t a l l o f t h e n e u t r a l l i p i d f r a c t i o n c o n s i s t e d o f t r i g l y c e r -  i d e , and 2) t h a t a l l o f t h e p o l a r l i p i d f r a c t i o n c o n s i s t e d o f p h o s p h o l i p i d . Neutral l i p i d  fractions  were a n a l y s e d  f o r t r i g l y c e r i d e u s i n g t h e method o f  F o s t e r and Dunn (1973) and t h e p o l a r l i p i d f r a c t i o n s  were a n a l y s e d f o r  p h o s p h o l i p i d u s i n g t h e method o f Raheja e t a l . (1973).  Not a l l o f t h e  weight o f a p h o s p h o l i p i d o r t r i g l y c e r i d e m o l e c u l e i s f a t t y a c i d . factors  as c a l c u l a t e d  by C h r i s t i e  (1973) were used t o c o n v e r t  the t o t a l m o l e c u l e t o t h e w e i g h t o f f a t t y a c i d s p r e s e n t The  conversion  factors  were 1.326 (based on p h o s p h a t i d y l  the weight of  i n the molecule. choline  f o r p h o s p h o l i p i d , and 0.996 (based on t r i o l e i n ) f o r t r i g l y c e r i d e . calculate  t h e w e i g h t o f f a t t y a c i d / g wet t i s s u e  Correction  the f o l l o w i n g  dioleoyl) Thus, t o  calculations  were used: 1 1.326  *  % crude l i p i d 100  for the p o l a r l i p i d 1 0.996  X  p h o s p h o l i p i d as a % o f crude l i p i d 100  X  f r a c t i o n , and  % crude l i p i d 100  X  U  . _ p h o s p h o l i p i d as a % o f crude l i p i d . 100 ;  f o r f a t t y a c i d s from t h e n e u t r a l l i p i d f r a c t i o n . wet  tissue,  i n t h e whole l i p i d was c a l c u l a t e d  The w e i g h t o f f a t t y  by t o t a l l i n g t h e w e i g h t s f o r  a l l o f t h e v a r i o u s f a t t y a c i d s i n t h e n e u t r a l and p o l a r f r a c t i o n s . dividing  acid/g  By  t h e w e i g h t o f f a t t y a c i d / g wet t i s s u e o f each o f t h e v a r i o u s t y p e s  of whole l i p i d f a t t y a c i d s by t h e t o t a l w e i g h t o f f a t t y a c i d s / g wet t i s s u e , the c o n t e n t  of the various types of f a t t y acid  i n whole l i p i d c o u l d be  e x p r e s s e d as a p e r c e n t . The  f a t t y a c i d composition  was condensed i n t o s e v e r a l  S a t u r a t e s were those f a t t y a c i d s w i t h o u t  double bonds.  groupings.  Monounsaturates were  17  those f a t t y a c i d s h a v i n g one double bond.  Polyunsaturated f a t t y acids  were those f a t t y a c i d s h a v i n g more than one double bond.  Fatty acids with  more than one double bond, but w i t h the f i r s t double bond, a t carbon 6 o r carbon 3 ( c o u n t i n g from the m e t h y l end) were termed u)6 arid w3 f a t t y a c i d s respectively. i n these VII.  F a t t y a c i d s w h i c h were l i s t e d as unknown were n o t i n c l u d e d  groupings.  Data H a n d l i n g and S t a t i s t i c a l A n a l y s i s C o n d i t i o n f a c t o r , used as a measure o f the r e l a t i o n s h i p between w e i g h t  and l e n g t h  :  was c a l c u l a t e d a s : 3 25  wet w e i g h t g / ( f o r k l e n g t h cm) * Computer programs, developed  x 1000 (Vanstone and M a r k e r t  1968).  a t t h e U n i v e r s i t y o f B. C. Computing  C e n t r e , and t h e U n i v e r s i t y o f B. C. B i o s c i e n c e s Data Centre were used f o r data a n a l y s i s .  Data were s u b j e c t e d t o a n a l y s i s o f v a r i a n c e (program ANVAR),  and then S c h e f f e ' s t e s t , t o d e t e c t d i f f e r e n c e s between means.  There were  s e v e r a l cases where, a c c o r d i n g t o B a r t l e t t ' s t e s t , the a s s u m p t i o n o f homogeneity o f v a r i a n c e was v i o l a t e d .  K r u s k a l W a l l i s t e s t and T - t e s t , when  a p p l i e d t o these cases r e s u l t e d i n t h e same c o n c l u s i o n as t h e a n a l y s i s o f variance.  T h e r e f o r e , i t was assumed t h a t the a n a l y s i s o f v a r i a n c e was  r o b u s t and the h e t e r o g e n e i t y o f v a r i a n c e was i g n o r e d . VIII.  Fish Health Qualicum coho p a r r , from t h e p r o d u c t i o n - c h a n n e l  and r e a r i n g - c h a n n e l ,  and n a t u r a l s m o l t s were i n s p e c t e d by t h e D i a g n o s t i c S e r v i c e , P a c i f i c B i o l o g i c a l S t a t i o n , Nanaimo, B. C.  No b a c t e r i a l o r v i r a l d i s e a s e s were  e n c o u n t e r e d i n w i l d s m o l t s n o r were t h e smolts h e a v i l y p a r a s i t i z e d .  Wild  s m o l t s had l e s s a d i p o s e t i s s u e than t h a t n o r m a l l y found i n c u l t u r e d s m o l t s .  18  There were some s i g n s o f s t r e s s i n c l u d i n g c l u b b i n g and edema o f g i l l l a m e l l a e , and eye c a t a r a c t s .  These symptoms were most l i k e l y a r e s u l t o f  the c a p t u r e and h o l d i n g methods.  No b a c t e r i a l d i s e a s e s were encountered i n  rearing-channel or production-channel  coho p a r r .  I n the r e a r i n g - c h a n n e l  p a r r , 27% o f the f i s h sampled c o n t a i n e d e i t h e r Myxidium parasite) or Cryptobia ( b i f l a g e l l a t e d protozoan).  (myxosporidian  In the production-  channel coho t h e i n c i d e n c e o f t h e s e two p a r a s i t e s was 6.0%.  The  of i n f e c t e d f i s h i s unknown (G. H o s k i n s , p e r s o n a l communication).  prognosis  19  RESULTS  I.  L e n g t h , Weight, and C o n d i t i o n F a c t o r A.  Coho Salmon from t h e Qualicum R i v e r  Production-channel  p r e s m o l t s were s i g n i f i c a n t l y l a r g e r than r e a r i n g -  channel o r w i l d p r e s m o l t s b o t h i n l e n g t h and w e i g h t (Table 2 ) .  Rearing-  channel and w i l d p r e s m o l t s a l s o d i f f e r e d i n s i z e w i t h t h e r e a r i n g - c h a n n e l presmolts  significantly  Production-channel  larger. smolts had t h e l a r g e s t l e n g t h and w e i g h t .  There  were o n l y s l i g h t d i f f e r e n c e s i n s i z e between r e a r i n g - c h a n n e l and n a t u r a l l y reared  smolts.  W i l d p r e s m o l t s and s m o l t s had h i g h e r c o n d i t i o n f a c t o r s than production-channel  coho (Table 2 ) .  Rearing-channel  smolts had the h i g h e s t  c o n d i t i o n f a c t o r f o l l o w e d by w i l d and then p r o d u c t i o n - c h a n n e l  smolts.  Qualicum coho l e n g t h s , w e i g h t s , and c o n d i t i o n f a c t o r s were measured a t three-month i n t e r v a l s over t h e p e r i o d May, 1978 to May, 1979. channel coho m a i n t a i n e d ( F i g . 5,6).  Production-  t h e l a r g e s t l e n g t h and w e i g h t d u r i n g t h i s p e r i o d  W i l d coho remained the s m a l l e s t i n l e n g t h and w e i g h t w i t h the  r e a r i n g - c h a n n e l coho i n t e r m e d i a t e i n s i z e .  D i f f e r e n c e s i n s i z e apparent  a t the l a t e f r y stage tended to i n c r e a s e as the f i s h grew t o t h e smolt stage.  I n a l l f i s h groups, c o n d i t i o n f a c t o r s decreased  and May, 1979 ( F i g . 7 ) .  between May,  There was no c o n s i s t e n t r e l a t i o n s h i p between the  t h r e e groups o f f i s h d u r i n g the e n t i r e p e r i o d .  However, as t h e f i s h  approached the smolt s t a g e , t h e c o n d i t i o n f a c t o r o f p r o d u c t i o n - c h a n n e l w i l d coho d e c l i n e d s h a r p l y w h i l e t h a t o f the r e a r i n g - c h a n n e l coho increased.  1978  and  20  B.  Coho Salmon from t h e C a p i l a n o R i v e r  H a t c h e r y s m o l t s were s i g n i f i c a n t l y l o n g e r than the w i l d coho i n f o r k l e n g t h (Table 2 ) . Consequently,  There were, however, no d i f f e r e n c e s i n wet w e i g h t .  the h a t c h e r y s m o l t s had a lower c o n d i t i o n f a c t o r .  W i l d C a p i l a n o s m o l t s were s l i g h t l y l a r g e r than t h e Qualicum s m o l t s i n l e n g t h and w e i g h t .  T h i s i s no doubt a r e s u l t of the g r e a t e r number o f  t w o - y e a r - o l d s m o l t s i n the C a p i l a n o system.  C a p i l a n o s m o l t s were much  slimmer than the Qualicum s m o l t s as i n d i c a t e d by t h e lower c o n d i t i o n f a c t o r . C.  S t e e l h e a d T r o u t from the Keogh R i v e r  W i l d and p e n - r e a r e d s t e e l h e a d were s i m i l a r i n l e n g t h , w e i g h t , and c o n d i t i o n f a c t o r (Table 2 ) . II.  Proximate  Composition  P r o x i m a t e c o m p o s i t i o n has been e x p r e s s e d as a p e r c e n t o f the wet t i s s u e , the d r y t i s s u e , and the l i p i d - f r e e d r y t i s s u e .  E x p r e s s i n g the  d a t a o n l y as a p e r c e n t of wet t i s s u e o r d r y t i s s u e would tend t o mask d i f f e r e n c e s i n a s h and p r o t e i n i f the f i s h v a r i e d i n m o i s t u r e o r l i p i d . S i n c e the f i s h i n t h i s study d i f f e r e d i n m o i s t u r e and l i p i d , a l l t h r e e methods o f e x p r e s s i n g the d a t a were used.  P h o s p h o l i p i d and f a t t y a c i d  c o n t e n t were o n l y e x p r e s s e d as a p e r c e n t o f the wet t i s s u e , s i n c e d i f f e r e n c e s i n m o i s t u r e c o n t e n t i n coho and s t e e l h e a d s m o l t s were n o t l i k e l y to mask the v e r y l a r g e d i f f e r e n c e s i n l i p i d . A.  Coho Salmon from t h e Qualicum R i v e r 1.  P r e s m o l t s and Smolts  When e x p r e s s e d as a p e r c e n t o f t h e wet t i s s u e , w i l d p r e s m o l t s were s i g n i f i c a n t l y h i g h e r i n m o i s t u r e b u t l o w e r i n p r o t e i n and l i p i d production-channel presmolts (Table 3 ) .  than t h e  There were no d i f f e r e n c e s i n ash  21  content. W i l d s m o l t s a l s o had h i g h e r m o i s t u r e and lower l i p i d  than p r o d u c t i o n -  c h a n n e l s m o l t s ; d i f f e r e n c e s i n p r o t e i n , however, were s l i g h t . channel and w i l d s m o l t s were s i m i l a r i n m o i s t u r e and l i p i d .  RearingProtein i n  the r e a r i n g - c h a n n e l s m o l t s was s i g n i f i c a n t l y lower than e i t h e r t h e production-channel or w i l d smolts.  Ash c o n t e n t i n t h e t h r e e groups o f  s m o l t s was s i m i l a r . When expressed as a p e r c e n t o f t h e d r y t i s s u e , s e v e r a l o t h e r d i f f e r ences i n c o m p o s i t i o n were e v i d e n t (Table 4 ) . W i l d p r e s m o l t s and s m o l t s were s i g n i f i c a n t l y h i g h e r than t h e p r o d u c t i o n - c h a n n e l coho i n a s h and p r o t e i n , w h i l e l i p i d was a g a i n s i g n i f i c a n t l y l o w e r .  Rearing-channel  p r e s m o l t s and s m o l t s remained i n t e r m e d i a t e i n d r y t i s s u e c o m p o s i t i o n . When e x p r e s s e d as a p e r c e n t o f t h e l i p i d - f r e e d r y t i s s u e , few s i g n i f i c a n t d i f f e r e n c e s i n a s h o r p r o t e i n were noted between n a t u r a l l y and a r t i f i c i a l l y - r e a r e d coho (Appendix  table 4).  Thus i t appears t h a t t h e  d i f f e r e n c e s i n a s h and p r o t e i n (% d r y t i s s u e ) were merely p r o p o r t i o n a l d i f f e r e n c e s r e s u l t i n g from t h e lower l i p i d c o n t e n t i n w i l d coho.  Therefore,  d i f f e r e n c e s i n p r o x i m a t e c o m p o s i t i o n were c o n f i n e d t o m o i s t u r e and l i p i d . 2.  F r y and P a r r  W i l d f r y and p a r r were h i g h e r i n m o i s t u r e and lower i n l i p i d and p r o t e i n than p r o d u c t i o n - c h a n n e l f r y ( F i g . 8-11).  These d i f f e r e n c e s were  m a i n t a i n e d and i n some cases p r o g r e s s i v e l y i n c r e a s e d t o t h e smolt s t a g e . There were no d i f f e r e n c e s i n a s h c o n t e n t .  Over t h e p e r i o d May, 1978 t o  J a n u a r y , 1979 t h e c o m p o s i t i o n o f t h e r e a r i n g - c h a n n e l coho was more l i k e t h a t o f t h e p r o d u c t i o n - c h a n n e l coho than t h e w i l d coho.  After  January,  however, t h e c o m p o s i t i o n o f t h e r e a r i n g - c h a n n e l coho approached t h a t o f t h e  22  w i l d coho.  The p a t t e r n was  the same when the d a t a were e x p r e s s e d as a  p e r c e n t o f d r y t i s s u e except t h a t ash and p r o t e i n remained h i g h e r i n w i l d coho than p r o d u c t i o n - c h a n n e l coho (Appendix t a b l e s B.  Coho Salmon from the C a p i l a n o R i v e r  W i l d s m o l t s had a h i g h e r m o i s t u r e c o n t e n t (% wet lipid  1-3).  than h a t c h e r y s m o l t s ( T a b l e 3 ) .  or p r o t e i n .  t i s s u e ) but lower  There were no d i f f e r e n c e s i n ash  The c o m p o s i t i o n o f the dry t i s s u e of w i l d s m o l t s was  than the h a t c h e r y s m o l t s i n ash and p r o t e i n but lower i n l i p i d  higher  (Table 4 ) .  As i n the Qualicum coho, t h e r e were no d i f f e r e n c e s i n ash and p r o t e i n when e x p r e s s e d as a p e r c e n t of the l i p i d - f r e e dry t i s s u e (Appendix t a b l e 4 ) . D i f f e r e n c e s between w i l d and h a t c h e r y coho were thus c o n f i n e d to m o i s t u r e and  lipid. C.  S t e e l h e a d T r o u t from the Keogh R i v e r  The c o m p o s i t i o n of the s t e e l h e a d s m o l t s d i d not f i t the p a t t e r n observed i n w i l d and h a t c h e r y coho. c o n t e n t , but i t was  The o n l y d i f f e r e n c e s Were i n l i p i d  the w i l d s m o l t s w i t h the h i g h e s t l i p i d  content  ( T a b l e 3-4, Appendix t a b l e 4 ) . D.  S e a s o n a l Changes i n Qualicum Coho  Monthly v a r i a t i o n s i n p r o x i m a t e c o m p o s i t i o n f o r w i l d Qualicum coho a r e summarized i n F i g . 8-11. was  Seasonal changes were not s t r i k i n g .  a g r a d u a l d e c l i n e i n m o i s t u r e over the p e r i o d May  There  to November,  1978  w i t h an i n c r e a s e to A p r i l , 1979.  Ash c o n t e n t i n c r e a s e d g r a d u a l l y from  1.5%  1979.  i n May,  1978  t o 2.5%  i n May,  There was  l i t t l e change i n  p r o t e i n o r l i p i d over w i n t e r ; however, t h e r e were major a l t e r a t i o n s i n p r o x i m a t e c o m p o s i t i o n a t the f r y and smolt s t a g e s of the l i f e  history.  A t the f r y s t a g e , p r o t e i n i n c r e a s e d s h a r p l y d u r i n g the p e r i o d May  to  23  August, 1978, w h i l e l i p i d decreased.  E x p r e s s i n g the d a t a as a p e r c e n t  of  the l i p i d - f r e e dry t i s s u e r e v e a l e d a c o n s t a n t p r o t e i n c o n t e n t of  to  85.9%  (May-August, 1978).  Thus, the i n c r e a s e i n p r o t e i n (% wet  i s a p r o p o r t i o n a l one o n l y , r e s u l t i n g from changes i n l i p i d  84.1 tissue)  content.  Comparing p r e s m o l t s and s m o l t s , m o i s t u r e d e c l i n e d and l i p i d i n c r e a s e d i n a l l t h r e e f i s h groups.  P r o t e i n i n c r e a s e d between w i l d and p r o d u c t i o n -  c h a n n e l p r e s m o l t s and s m o l t s (% wet t i s s u e ) a l t h o u g h a g a i n the changes i n p r o t e i n a r e l i k e l y p r o p o r t i o n a l as t h e r e was a dry t i s s u e b a s i s ( T a b l e 4 ) .  l i t t l e change i n p r o t e i n on  I n summary, the g r e a t e s t s e a s o n a l v a r i a t i o n s  i n p r o x i m a t e c o m p o s i t i o n a r e i n m o i s t u r e and  lipid.  E.  A q u a t i c I n s e c t s and H a t c h e r y D i e t s  Due  to the s m a l l amount o f i n s e c t t i s s u e a v a i l a b l e f o r p r o x i m a t e  c o m p o s i t i o n , o n l y the l i p i d c o n t e n t c o u l d be determined.  Plecoptera,  Chironomidae and T r i c h o p t e r a were s i m i l a r i n l i p i d c o n t e n t ( T a b l e 5 ) . l i p i d c o n t e n t i n Ephemeroptera was insect  a p p r o x i m a t e l y double t h a t of the o t h e r  groups.  S i l v e r Cup,  a dry d i e t , had a much lower m o i s t u r e c o n t e n t than Oregon  Moist P e l l e t (Table 5).  On a d r y w e i g h t b a s i s the h a t c h e r y d i e t s were  s i m i l a r i n ash and p r o t e i n c o n t e n t . was  The  L i p i d c o n t e n t itt S i l v e r Cup  lower than i n Oregon M o i s t P e l l e t (18.31%).  (12.98%)  Expressed on a wet  weight  b a s i s , the l i p i d c o n t e n t i n the h a t c h e r y d i e t s was much h i g h e r than the l i p i d content i n aquatic i n s e c t s .  24  III.  P h o s p h o l i p i d Content P h o s p h o l i p i d c o n t e n t was e x p r e s s e d as a percentage  of the crude  lipid  and as mg p h o s p h o l i p i d / g wet t i s s u e . As." the crude l i p i d c o n t e n t i n f i s h t i s s u e i n c r e a s e d , the percentage makeup o f p h o s p h o l i p i d decreased  (Table 3 ) .  Thus w i l d coho smolts from the Qualicum and C a p i l a n o r i v e r s had s i g n i f i c a n t l y higher percentage  c o n t e n t s o f p h o s p h o l i p i d than h a t c h e r y s m o l t s .  s t e e l h e a d from the Keogh r i v e r had a s i g n i f i c a n t l y h i g h e r c o n t e n t o f p h o s p h o l i p i d than t h e w i l d s t e e l h e a d s m o l t s .  Pen-reared  percentage W i t h one e x c e p t i o n ,  the weight o f p h o s p h o l i p i d / g wet t i s s u e was s i m i l a r i n h a t c h e r y and w i l d coho, and p e n - r e a r e d  and w i l d s t e e l h e a d .  p h o s p h o l i p i d than t h e coho.  S t e e l h e a d as a group had l e s s  Changes i n p h o s p h o l i p i d c o n t e n t d u r i n g s m o l t i n g  were s l i g h t .  IV.  Fatty Acid A.  Composition  Individual Fatty Acid 1.  Composition  Fish  I n d i v i d u a l f a t t y a c i d s were e x p r e s s e d as a percentage  of t h e t o t a l  amount o f f a t t y a c i d s , and as a weight o f f a t t y a c i d / g wet t i s s u e . G e n e r a l l y , t h e same f a t t y a c i d s were p r e s e n t i n a l l o f the f i s h samples; however, t h e r e were s u b s t a n t i a l d i f f e r e n c e s i n the amounts o f the v a r i o u s fatty acids. i.  Coho Smolts from t h e Qualicum R i v e r  On a percentage  b a s i s , p r o d u c t i o n - c h a n n e l and r e a r i n g - c h a n n e l s m o l t s  were much h i g h e r i n 20:lu)9 and 22:1OJ9 ( T a b l e 6-8). t r a c e amounts o f 22:1OJ9. form o f 18:2u6 and 20:4w6.  W i l d smolts had o n l y  The oi6 f a t t y a c i d s were s t o r e d p r i m a r i l y i n t h e The c o n t e n t o f 18:2co6 was always h i g h e r i n  n e u t r a l l i p i d , w h i l e the c o n t e n t o f 20:4w6 was h i g h e r i n p o l a r l i p i d .  25  The  18:2w6 c o n t e n t was  h i g h e s t i n the p r o d u c t i o n - c h a n n e l  n e u t r a l and  whole l i p i d w i t h o n l y s l i g h t d i f f e r e n c e s .in p o l a r c o n t e n t .  On the o t h e r  hand, w i l d s m o l t s were h i g h e s t i n 20:4oi6 c o n t e n t , i n n e u t r a l and lipid.  polar  F a t t y a c i d s o f the u)3 s e r i e s were s t o r e d i n the form o f 18:3o>3,  20:5CJ3, 22:5a)3,  and 22:6w3.  higher i n polar l i p i d and 22:5w3 was  F a t t y a c i d s o f the u)3 s e r i e s were u s u a l l y  than n e u t r a l l i p i d .  highest i n w i l d smolts.  The  c o n t e n t o f 18:3co3, 20:5w3,  Production  and  rearing-channel  s m o l t s were s i m i l a r i n 18:3u)3, 20:5OJ3, and 22:6a>3 c o n t e n t .  Considerable  d i f f e r e n c e s were found i n the c o n t e n t of 22:6a>3, the form i n w h i c h most of the w3  f a t t y a c i d s were s t o r e d .  l i p i d was  2.2  The  22:6w3 c o n t e n t i n w i l d smolt n e u t r a l  times t h a t of the p r o d u c t i o n .or r e a r i n g - c h a n n e l  However, i n p o l a r l i p i d ,  the p r o d u c t i o n - c h a n n e l  smolts.  s m o l t s had the h i g h e s t  22:6w3 c o n t e n t , w i t h s i m i l a r amounts i n the r e a r i n g - c h a n n e l and w i l d F a t t y a c i d c o n t e n t was  a l s o expressed  as a w e i g h t / g wet  c a l c u l a t i o n assumed t h a t n e u t r a l l i p i d c o n s i s t e d e n t i r e l y of and t h a t p o l a r l i p i d c o n s i s t e d e n t i r e l y o f p h o s p h o l i p i d . t r i a c y l g l y c e r o l c o n t e n t i n n e u t r a l l i p i d was c o n t e n t of p o l a r l i p i d was higher i n production  90%.  The a c t u a l  85% w h i l e t h e p h o s p h o l i p i d much  and r e a r i n g - c h a n n e l coho, w i t h the g r e a t e s t d i f f e r ^ -  f a t t y a c i d s , 18:2oo6 was  (Table 6-8).  C o n c e r n i n g the  w6  h i g h e s t i n p r o d u c t i o n c h a n n e l n e u t r a l and whole  l i p i d w i t h l i t t l e d i f f e r e n c e i n the p o l a r l i p i d  content.  The 20:4u>6  h i g h e s t i n w i l d s m o l t s n e u t r a l , p o l a r and whole l i p i d .  w3 f a t t y a c i d s , the 18:3o>3 c o n t e n t o f n e u t r a l and p o l a r l i p i d was i n w i l d smolts.  This  triacylglycerol  The weight of 20:lco9 and 22:lw9 was  ences o c c u r r i n g i n n e u t r a l and whole l i p i d  c o n t e n t was  tissue.  smolts.  I n the highest  A l l t h r e e groups o f f i s h were s i m i l a r i n 20:5w3 and 22:5o)3  w i t h the e x c e p t i o n of lower 22:5o)3 i n n e u t r a l l i p i d o f r e a r i n g - c h a n n e l coho.  26  P r o d u c t i o n - c h a n n e l and w i l d s m o l t s were s i m i l a r i n 22:6u3 c o n t e n t o f n e u t r a l l i p i d , w h i l e t h e c o n t e n t i n n e u t r a l l i p i d o f r e a r i n g - c h a n n e l coho was h a l f t h a t o f t h e o t h e r two groups.  The c o n t e n t o f 22:6w3 i n w i l d  smolt p o l a r l i p i d was s l i g h t l y lower than t h e o t h e r two groups, ii.  S t e e l h e a d Smolts from t h e Keogh R i v e r  As i n t h e coho s m o l t s , t h e r e was more 18:2w6 i n n e u t r a l l i p i d and more 20:4oi6- and 22:6aBin p o l a r l i p i d  ( T a b l e 9,10).  There were n o t i c e a b l e  d i f f e r e n c e s i n u)6 f a t t y a c i d c o n t e n t o f pen-reared percentage  c o n t e n t o f 18:2o)6 i n pen-reared  the w i l d s m o l t s . as w e l l .  The  s m o l t s was n i n e times t h a t o f  There were l a r g e d i f f e r e n c e s i n 18:2u)6 on a weight b a s i s  D i f f e r e n c e s i n 20:4w6 were n o t as s t r i k i n g as i n 18:2w6.  18:3co3 percentage smolts.  and w i l d s m o l t s .  content of pen-reared  The  s m o l t s was t w i c e t h a t o f w i l d  I n c o n t r a s t t h e 20:5w3 and 22:5w3 c o n t e n t i n w i l d smolt n e u t r a l and  p o l a r l i p i d was h i g h e r than t h e pen-reared  smolts.  The n e u t r a l l i p i d  c o n t e n t o f 22:6w3 was much h i g h e r i n w i l d s m o l t s , b o t h on a p e r c e n t and a weight b a s i s ; however, t h e p o l a r l i p i d c o n t e n t was s i m i l a r . 2.  A q u a t i c I n s e c t s and H a t c h e r y D i e t s  Ephemeroptera and T r i c h o p t e r a were s i m i l a r ' i n f a t t y a c i d (Table 11).  content  P l e c o p t e r a d i f f e r e d from t h e s e two groups i n h a v i n g a lower  c o n t e n t o f 16:lw7 b u t a h i g h e r c o n t e n t o f 18:1OJ9 and 18:3CJ3.  Chironomidae  were much h i g h e r i n 18:2co6 c o n t e n t b u t lower i n 18:3co3 c o n t e n t .  In a l l of  the i n s e c t groups, t h e u)6 f a t t y a c i d s were s t o r e d p r i m a r i l y i n the form o f 18:2w6 w h i l e t h e to 3 f a t t y a c i d s were s t o r e d as 18:3(JO3 and 20:5w3.  The  22:6w3 c o n t e n t was v e r y low. The two h a t c h e r y d i e t s were v e r y d i f f e r e n t i n f a t t y a c i d (Table 11).  content  The S i l v e r Cup d i e t was h i g h e r i n 16:0, 18:2OJ6, 18:3w3, and  27  22:6o>3 but much lower i n 16:lu)7, 20:lo)9, and 22:lo)9.  F a t t y a c i d s of the  0)6 s e r i e s were i n the form of 18:2u>6 w h i l e the o>3 f a t t y a c i d s were i n the form o f 20:5o)3 and 22:6o)3.  There was  v e r y l i t t l e 18:3o>3 i n Oregon M o i s t  Pellet. In comparison w i t h the a q u a t i c i n s e c t s , the h a t c h e r y d i e t s were lower i n 18:3u)3 but h i g h e r i n 20:lo>9, 22:lu)9, and 22:6oi3.  S i l v e r Cup was  much  h i g h e r than the i n s e c t groups i n 18:2o>6. 3.  Comparison-of ,.the-Diet'.'..and• the F i s h  As noted  Composition  i n the p r e v i o u s s e c t i o n , the h a t c h e r y d i e t s were c h a r a c t e r i s -  t i c a l l y different i n several fatty acids.  These d i f f e r e n c e s were a l s o  e v i d e n t i n the f a t t y a c i d c o m p o s i t i o n of the h a t c h e r y f i s h . P e l l e t was  v e r y h i g h i n 20:lo)9 and 22:lo>9.  Production  and  Oregon M o i s t rearing-channel  coho, f e d Oregon M o i s t P e l l e t , had h i g h c o n t e n t s of t h e s e two f a t t y a c i d s . The h i g h 18:2o)6 i n S i l v e r Cup was pen-reared  steelhead.  r e f l e c t e d by the 18:2oi6 c o n t e n t i n  Rearing-channel  coho had  a q u a t i c i n s e c t s as w e l l as Oregon M o i s t P e l l e t .  the o p p o r t u n i t y to f e e d  on  U n f o r t u n a t e l y , t h e r e were  no d i s t i n c t i v e f e a t u r e s i n the f a t t y a c i d c o m p o s i t i o n o f the a q u a t i c i n s e c t s , t h u s , the i n f l u e n c e of these i n s e c t s on the c o m p o s i t i o n of r e a r i n g channel coho c o u l d not be B.  Fatty Acid Class  evaluated. Composition  I n d i v i d u a l f a t t y a c i d s were c l a s s i f i e d a c c o r d i n g to t h e i r degree and type o f u n s a t u r a t i o n as s a t u r a t e d , monounsaturated, p o l y u n s a t u r a t e d , o)6, and 0)3 f a t t y a c i d s .  28  1.  Fish i.  Coho Smolts from the Qualicum  River  The g r e a t e s t d i f f e r e n c e s i n f a t t y a c i d c l a s s c o m p o s i t i o n were found i n n e u t r a l and whole l i p i d .  When the c o m p o s i t i o n was  c a l c u l a t e d as a p e r c e n t -  age, the w i l d s m o l t s were h i g h e r than the p r o d u c t i o n - c h a n n e l s m o l t s i n s a t u r a t e d , p o l y u n s a t u r a t e d , and u>3 f a t t y a c i d s , but lower i n 0)6 and monounsaturated f a t t y a c i d s ( F i g . 12-16).  E x p r e s s e d as a w e i g h t / g  wet  t i s s u e , the s a t u r a t e d , monounsaturated, p o l y u n s a t u r a t e d , and o)6 f a t t y a c i d s were lower i n w i l d s m o l t s .  P r o d u c t i o n - c h a n n e l s m o l t s had the h i g h e s t u6  and p o l y u n s a t u r a t e d f a t t y a c i d c o n t e n t . c o n t e n t of r e a r i n g - c h a n n e l s m o l t s was a c i d class composition.  The n e u t r a l and whole l i p i d  i n most cases i n t e r m e d i a t e i n f a t t y  P o l a r l i p i d f r a c t i o n s were s i m i l a r i n c o m p o s i t i o n  w i t h the e x c e p t i o n of s l i g h t l y h i g h e r percentage o>6 f a t t y a c i d c o n t e n t i n w i l d smolts.  The r a t i o of co6/w3 f a t t y a c i d s was  p r o d u c t i o n - c h a n n e l n e u t r a l and whole l i p i d r a t i o was  s i g n i f i c a n t l y higher i n  ( F i g . 17).  In p o l a r l i p i d ,  the  s i g n i f i c a n t l y h i g h e r i n the w i l d s m o l t s . ii.  S t e e l h e a d Smolts from the Keogh R i v e r  E x p r e s s e d as a p e r c e n t , the monounsaturated, p o l y u n s a t u r a t e d , and u>3 f a t t y a c i d c o n t e n t o f n e u t r a l and whole l i p i d i n w i l d s m o l t s was c a n t l y h i g h e r than t h a t of the pen-reared  smolts.  i n s a t u r a t e d and w6 f a t t y a c i d s ( F i g . 18-22). the p o l a r l i p i d  signifi-  W i l d s m o l t s were lower  There were d i f f e r e n c e s i n  c o n t e n t as w e l l , w i t h the w i l d s m o l t s h i g h e r than the  pen-  r e a r e d s m o l t s i n monounsaturated and co3 f a t t y a c i d s , but lower i n p o l y u n s a t u r a t e d and w6 f a t t y a c i d s . On a weight b a s i s , w i l d smolt n e u t r a l and whole l i p i d  f r a c t i o n s were  h i g h e r i n s a t u r a t e d , monounsaturated, u)3, and p o l y u n s a t u r a t e d f a t t y a c i d s  29  but much lower i n 0)6 f a t t y a c i d s .  The p o l a r l i p i d  f r a c t i o n of w i l d  s m o l t s was much lower i n o>6 f a t t y a c i d s than t h e pen-reared r a t i o of  o)6/o>3  smolts.  f a t t y a c i d s was s i g n i f i c a n t l y h i g h e r i n pen-reared  The  smolts  f o r a l l of the l i p i d f r a c t i o n s ( F i g . 17). 2.  A q u a t i c I n s e c t s and H a t c h e r y D i e t s  Ephemeroptera, P l e c o p t e r a , and T r i c h o p t e r a were s i m i l a r i n f a t t y c l a s s composition (Table 12).  acid  Chironomidae was h i g h e r i n oi6 b u t lower i n  0)3 f a t t y a c i d s than t h e o t h e r i n s e c t groups,  and t h u s , t h e r a t i o o f  oi6/o)3  f a t t y a c i d s f o r Chironomidae was much h i g h e r . The Oregon M o i s t P e l l e t d i e t was h i g h e r than t h e S i l v e r Cup d i e t i n monounsaturated f a t t y a c i d s b u t lower i n s a t u r a t e d , p o l y u n s a t u r a t e d , 0)6, and o)3 f a t t y a c i d s ( T a b l e 1 2 ) . N e i t h e r h a t c h e r y d i e t was p a r t i c u l a r l y s i m i l a r  to the insect  groups.  The most o u t s t a n d i n g d i f f e r e n c e s were i n the monounsaturated and 0)6 f a t t y acids.  Oregon M o i s t P e l l e t was much h i g h e r than t h e a q u a t i c i n s e c t s i n  monounsaturates w h i l e S i l v e r Cup was h i g h e r i n o>6 f a t t y 3. Hatchery  Comparison o f t h e D i e t and the F i s h d i e t s were d i s t i n c t i v e l y d i f f e r e n t  acids.  Composition i n t h e i r content of  monounsaturated (Oregon M o i s t P e l l e t ) and o)6 ( S i l v e r Cup) f a t t y D i f f e r e n c e s were a l s o observed i n t h e f i s h f e d t h e s e d i e t s .  acids.  Rearing-  c h a n n e l and p r o d u c t i o n - c h a n n e l coho when f e d Oregon M o i s t P e l l e t were h i g h i n monounsaturated f a t t y a c i d c o n t e n t . Cup, were h i g h i n o>6 f a t t y a c i d s .  Pen-reared  steelhead, fed S i l v e r  As w i t h t h e c o m p o s i t i o n o f i n d i v i d u a l  f a t t y a c i d s , t h e r e were no d i s t i n c t i v e f e a t u r e s i n t h e f a t t y a c i d c l a s s c o m p o s i t i o n o f a q u a t i c i n s e c t s which would a l l o w t h e i r i n f l u e n c e i n r e a r i n g c h a n n e l coho t o be e v a l u a t e d .  30  V.  Age  of the Smolts  Hatchery  coho from the Qualicum and C a p i l a n o r i v e r s , and w i l d coho  from the Qualicum r i v e r smolted a t the age of 1+ y e a r s .  W i l d coho  smolts  from the C a p i l a n o r i v e r v a r i e d i n age from 1+ to 2+, w i t h 73% of the s m o l t i n g a t age 1+. the age of one y e a r . years.  fish  Keogh r i v e r s t e e l h e a d , r e a r e d i n n e t pens, smolted  at  W i l d s t e e l h e a d s m o l t s ranged i n age from t h r e e to f o u r  Data c o l l e c t e d by the F i s h and W i l d l i f e Branch suggest t h a t 75% o f  the w i l d s t e e l h e a d s m o l t s a r e age t h r e e (P. S l a n e y , p e r s o n a l communication).  31  DISCUSSION Having  i d e n t i f i e d the m o r p h o l o g i c a l and b i o c h e m i c a l d i f f e r e n c e s i n  w i l d and h a t c h e r y s a l m o n i d s , p a r t I o f the d i s c u s s i o n w i l l c o n s i d e r the e f f e c t of r e a r i n g c o n d i t i o n s on f i s h morphology and b i o c h e m i s t r y .  The  impact o f these m o r p h o l o g i c a l and b i o c h e m i c a l d i f f e r e n c e s on marine s u r v i v a l w i l l be c o n s i d e r e d i n p a r t I I . I.  I n f l u e n c e o f R e a r i n g C o n d i t i o n s on Morphology and A.  Biochemistry  L e n g t h , Weight, and C o n d i t i o n F a c t o r  Hatchery  coho were l o n g e r and h e a v i e r than the w i l d coho ( T a b l e 2 ) .  D i f f e r e n c e s i n l e n g t h and weight were e v i d e n t a t the f r y s t a g e maintained  throughout  and  the f r e s h w a t e r p o r t i o n of the l i f e h i s t o r y .  c i a l r e a r i n g of coho (Vanstone  and M a r k e r t 1968) , p i n k salmon ( B a i l e y e_t  a l . 1976), and h e r r i n g ( B a l b o n t i n j i t a l . 1973) l a r g e r i n l e n g t h and weight  Artifi-  r e s u l t e d i n f i s h t h a t were  than the w i l d f i s h .  At l e a s t f o r the coho and  p i n k salmon, the f i s h were of s i m i l a r age and g e n e t i c background. E v i d e n t l y , the abundant f o o d s u p p l y and f a v o u r a b l e r e a r i n g c o n d i t i o n s r e s u l t e d i n h i g h growth r a t e s f o r h a t c h e r y - r e a r e d f i s h .  The s i z e  of w i l d and r e a r i n g - c h a n n e l coho appears t o be a r e f l e c t i o n of the  similarity semi-  n a t u r a l c o n d i t i o n s i n the rearing-channel. Some o f the sampling methods used i n t h i s study were p r o b a b l y selective.  size  Dip n e t s used f o r s a m p l i n g r e a r i n g - c h a n n e l , p r o d u c t i o n - c h a n n e l ,  and Burrows pond coho would tend to s e l e c t f o r s m a l l e r f i s h w h i l e e l e c t r o s h o c k i n g used f o r s a m p l i n g w i l d coho would tend to s e l e c t f o r l a r g e r fish.  Thus, the d i f f e r e n c e s i n s i z e between w i l d and c u l t u r e d coho a r e  l i k e l y t o be s l i g h t l y  underestimated.  Pen-reared  s t e e l h e a d were v e r y  32  u n i f o r m i n s i z e , t h e r e f o r e , s i z e s e l e c t i o n would not be a problem.  Wild  coho and s t e e l h e a d s m o l t s were c o l l e c t e d w i t h f y k e n e t s o r downstream t r a p s . These methods would not be s i z e  selective.  The growth r a t e o f w i l d Qualicum coho from p r e s m o l t to smolt e x c e p t i o n a l a t 1.92%  body weight  per day  w i l d coho i s not w i t h o u t precedent a growth r a t e o f 4.4%  ( F i g . 6).  was  T h i s growth r a t e f o r  as Vanstone and M a r k e r t  body weight per day f o r coho s m o l t s .  (1968) r e c o r d e d Both o f the  above growth r a t e s o c c u r r e d subsequent to a w i n t e r p e r i o d of low water temperatures  and decreased  p r e v i o u s l y f e d a reduced r a t e upon r e s u m p t i o n  food a v a i l a b i l i t y .  I n the l a b o r a t o r y , salmon,  r a t i o n , have a l s o demonstrated a v e r y h i g h growth  of normal f e e d i n g ( G r i f f i o e n and N a r v e r .  1974).  C o n d i t i o n f a c t o r s were lower i n c u l t u r e d than i n w i l d coho.  Condition  f a c t o r , a t l e a s t f o r some f i s h , i s a measure o f body shape and body energy r e s e r v e s such t h a t f i s h w i t h a s t o u t e r shape and/or i n c r e a s e d energy r e s e r v e s have h i g h e r c o n d i t i o n f a c t o r s ( B l a x t e r 1975).  However, i n t h i s  study c o n d i t i o n f a c t o r was not a r e l i a b l e measure of body energy r e s e r v e s as w i l d coho had the h i g h e s t c o n d i t i o n f a c t o r but t h e l o w e s t l i p i d  content.  A l t h o u g h the h i g h e r c o n d i t i o n f a c t o r i n w i l d coho may  represent d i f f e r e n c e s  i n f i s h shape, any f a c t o r w h i c h i n c r e a s e s f i s h weight  to a g r e a t e r e x t e n t  than f i s h l e n g t h w i l l  Therefore,  i n c r e a s e the c o n d i t i o n f a c t o r .  g r e a t e r m o i s t u r e c o n t e n t i n w i l d coho c o u l d a l s o account  the  f o r t h e i r higher  condition factor. B.  Proximate 1.  Composition  Comparisons o f N a t u r a l l y  and•Artificially-reared'Fish  In ' t h i s s t u d y , n a t u r a l l y - r e a r e d s m o l t s were h i g h e r i n m o i s t u r e lower i n l i p i d than the a r t i f i c i a l l y - r e a r e d  smolts ( T a b l e 3 ) .  and  On a dry  33  t i s s u e b a s i s , w i l d coho were h i g h e r than the c u l t u r e d protein  ( T a b l e 4 ) , a l t h o u g h few d i f f e r e n c e s  dry t i s s u e b a s i s .  were apparent on a l i p i d - f r e e  P r o x i m a t e c o m p o s i t i o n s o f w i l d and c u l t u r e d  been compared f o r rainbow t r o u t 1978), brook t r o u t  ( P a p o u t s o g l o u and  Papoutsoglou  Papaparaskeva-Papoutsoglou  I n a l l o f t h e s e s t u d i e s , w i l d f i s h were  h i g h e r i n p r o t e i n and ash and l o w e r i n l i p i d fish.  f i s h have  ( P h i l l i p s e t a l . 1957), salmon (Wood e t a l . 1957), and  p l a i c e (Cowey and Sargent 1972).  cultured  coho i n ash and  (% d r y t i s s u e )  However, when the d a t a o f P a p o u t s o g l o u and  than the Papaparaskeva-  (1978), P h i l l i p s e t a l . (1957) and Cowey and Sargent (1972)  were e x p r e s s e d as a p e r c e n t o f t h e l i p i d - f r e e d r y t i s s u e , d i f f e r e n c e s i n p r o t e i n and ash between w i l d and c u l t u r e d  f i s h were v e r y much reduced.  The  d a t a from Wood e_t a l . (1957) c o u l d n o t be c o n v e r t e d t o a l i p i d - f r e e d r y tissue basis appears  s i n c e salmon m o i s t u r e c o n t e n t s were n o t g i v e n .  t h a t the major d i f f e r e n c e s  and c u l t u r e d  i n p r o x i m a t e c o m p o s i t i o n between w i l d  f i s h a r e c o n f i n e d t o m o i s t u r e and l i p i d .  Most o f the s t u d i e s cultured  Thus i t  comparing  p r o x i m a t e c o m p o s i t i o n i n w i l d and  f i s h have been made on a s i n g l e l i f e h i s t o r y s t a g e .  T h i s study  compared t h e f i s h throughout the f r e s h w a t e r p o r t i o n o f t h e l i f e revealing  that differences  history  i n p r o x i m a t e c o m p o s i t i o n were e v i d e n t a t a v e r y  e a r l y age ( F i g . 8-11). The h i g h e r m o i s t u r e c o n t e n t i n w i l d coho i s e x p l a i n e d by the i n v e r s e r e l a t i o n s h i p between body l i p i d and m o i s t u r e (Love 1970). h i g h e r m o i s t u r e i n w i l d than c u l t u r e d  Thus, the  coho was a r e s u l t of t h e low l i p i d  c o n t e n t i n w i l d coho. Body l i p i d i s i n f l u e n c e  by many f a c t o r s i n c l u d i n g water  temperature  ( B r e t t e t a l . 1969), r a t i o n l e v e l ( B r e t t e t a l . 1969), and d i e t c o m p o s i t i o n  34  (Ogino a t a l . 1976).  The i n f l u e n c e o f water temperature depends on the  r a t i o n l e v e l a t which the f i s h a r e being f e d .  A t a r a t i o n l e v e l o f 3%  of t h e d r y body w e i g h t p e r day, i n c r e a s i n g t h e water temperature from 5 t o 10°C  r e s u l t e d i n a 30% decrease i n sockeye body l i p i d  ( B r e t t e t a l . 1969).  However, a t t h e maximum d i e t a r y food i n t a k e , i n c r e a s i n g water temperature from 5 t o 10°C r e s u l t e d i n o n l y a 7% d e c r e a s e i n l i p i d . p o s i t i v e l y c o r r e l a t e d w i t h body l i p i d  ( B r e t t a t a l . 1969) as i s the l i p i d  c o n t e n t o f t h e d i e t (Ogino et al. 1976). d i e t a r y l i p i d content w i l l  Ration l e v e l i s  Increasing the r a t i o n l e v e l or  i n c r e a s e t h e body  lipid.  In t h e p r e s e n t s t u d y , w a t e r t e m p e r a t u r e , r a t i o n l e v e l , and d i e t c o m p o s i t i o n f o r w i l d and c u l t u r e d f i s h d i f f e r e d i n t h e f o l l o w i n g manner. Where measured, t h e mean a n n u a l water temperature f o r n a t u r a l l y artificially-reared  f i s h was- s i m i l a r  not measured f o r w i l d f i s h  (Table 1 ) .  and  Ration l e v e l s , although  a r e l i k e l y t o be lower than f o r c u l t u r e d  C u l t u r e d f i s h a r e f e d t o excess a t a l l times o f t h e y e a r .  fish.  When f o o d i s  p l e n t i f u l , w i l d f i s h may a l s o f e e d t o s a t i a t i o n ; however, on an a n n u a l b a s i s , t h e r a t i o n s i z e f o r h a t c h e r y f i s h would l i k e l y be h i g h e r .  W i l d and  h a t c h e r y f i s h d i e t s d i f f e r e d i n c o m p o s i t i o n . A q u a t i c i n s e c t s (Ephemeropt e r a , P l e c o p t e r a , Chironomidae, T r i c h o p t e r a ) were much l o w e r than t h e hatchery d i e t s i n l i p i d  (% wet w e i g h t ) .  The r e l a t i v e c o n t r i b u t i o n o f  t h e s e i n s e c t groups t o the coho d i e t was n o t measured; however, s t u d i e s by Mundie (1969), Mundie and Mounce (1978), and E l l i o t  (1973) suggest t h a t t h e  a q u a t i c i n s e c t d i e t o f b o t h stream and r e a r i n g - c h a n n e l s a l m o n i d s i s made up, p r i m a r i l y o f Chironomidae and Ephemeroptera.  P h i l l i p s eit a l .  (1954)  measured t h e p r o x i m a t e c o m p o s i t i o n o f some n a t u r a l f i s h foods i n c l u d i n g P l e c o p t e r a , D i p t e r a , and Ephemeroptera.  On a wet w e i g h t b a s i s , i n s e c t  35  lipid  ( 2 . 2 % ) , a s h ( 1 . 7 % ) , and p r o t e i n (11.5%) c o n t e n t s were much lower  than i n Oregon M o i s t P e l l e t o r S i l v e r Cup.  However, when the a n a l y s e s o f  P h i l l i p s e t a l . (1954) were e x p r e s s e d on a d r y weight b a s i s by t h i s a u t h o r , t h e i n s e c t ash (9.6%) was s l i g h t l y lower than the h a t c h e r y d i e t s , t h e l i p i d (12.4%) was s i m i l a r t o S i l v e r Cup b u t lower than the Oregon M o i s t P e l l e t d i e t , and t h e p r o t e i n (66.8%) was h i g h e r than b o t h o f t h e h a t c h e r y  diets.  Thus, d i f f e r e n c e s i n c o m p o s i t i o n between a q u a t i c i n s e c t s , as a n a l y s e d by Phillips  e_t aJ-. (1954), and the h a t c h e r y d i e t s used i n t h i s s t u d y were  p r i m a r i l y i n p r o t e i n and l i p i d . I n summary, the major d i f f e r e n c e s i n the r e a r i n g c o n d i t i o n s o f w i l d and h a t c h e r y f i s h i n t h i s study were i n r a t i o n l e v e l s , and d i e t c o m p o s i t i o n . Rearing f a c i l i t i e s  a l s o d i f f e r e d i n f i s h d e n s i t y and w a t e r . c u r r e n t v e l o c i t y .  U n f o r t u n a t e l y , l i t t l e i s known on t h e i n f l u e n c e of f i s h r e a r i n g d e n s i t y o r water c u r r e n t v e l o c i t y on p r o x i m a t e c o m p o s i t i o n ; t h u s , they w i l l not be considered further. The g r e a t e r l i p i d c o n t e n t i n c u l t u r e d coho can be e x p l a i n e d by r e a r i n g condition differences.  The h i g h e r r a t i o n l e v e l s and l i p i d c o n t e n t o f the  d i e t o f p r o d u c t i o n - c h a n n e l and Burrows pond coho would tend t o produce f i s h w i t h a h i g h e r body l i p i d .  That the r e a r i n g - c h a n n e l coho, f e d Oregon M o i s t  P e l l e t a t h a l f the f r e q u e n c y o f the p r o d u c t i o n - c h a n n e l coho, had a body l i p i d i n t e r m e d i a t e between p r o d u c t i o n - c h a n n e l and w i l d coho (% d r y t i s s u e ) l e n d s f u r t h e r s u p p o r t t o t h e i n f l u e n c e of r a t i o n l e v e l s and d i e t on body  composition  lipid.  The g r e a t e r l i p i d c o n t e n t i n w i l d s t e e l h e a d than pen-reared can be p a r t i a l l y  steelhead  e x p l a i n e d by the lower l i p i d c o n t e n t i n the S i l v e r Cup d i e t  than Oregon M o i s t P e l l e t .  F u r t h e r m o r e , f a t a c c u m u l a t i o n i n c r e a s e s w i t h age  36  i n s a u r y , m a c k e r e l , e e l , anchovy, and s a r d i n e as young f i s h devote more of t h e i r energy i n t a k e t o growth than do o l d e r f i s h  (Shul'man 1974).  ,S:hul'man  (1974) n o t e s t h a t o l d e r f i s h are u s u a l l y l a r g e r i n s i z e , thus i t i s not c l e a r i f the i n c r e a s e i n l i p i d i s due were two and  to age or s i z e .  The w i l d  steelhead  t h r e e y e a r s o l d e r than the p e n - r e a r e d s t e e l h e a d but d i d not  differ in size.  A l t h o u g h age d i f f e r e n c e s might be the r e a s o n f o r the  h i g h e r l i p i d i n w i l d s t e e l h e a d , a d e f i n i t i v e e x p l a n a t i o n i s not  yet  available. 2.  S e a s o n a l Changes  Proximate composition  was  measured f o r Qualicum coho o v e r the f r e s h -  water p o r t i o n of the l i f e h i s t o r y . increased gradually (Fig. 9). phosphorus, c a l c i u m , and g r e a t e s t p o r t i o n (85%)  Phosphorus and c a l c i u m make up  of the m i n e r a l c o n t e n t  of f i s h ash  This d i v e r s e composition  d i f f i c u l t to i n t e r p r e t .  the i n c r e a s e i n ash c o n t e n t was  (% wet  tissue)  Ash c o n s i s t s of i n o r g a n i c i o n s such as  sodium.  p e r s o n a l communication). content  D u r i n g t h i s p e r i o d , ash  One  would s u s p e c t ,  at l e a s t p a r t i a l l y  the  (D. H i g g s ,  makes a change i n ash f o r the f r y s t a g e , due  that  to o s s i f i c a t i o n .  Coho demonstrated l i t t l e growth or u t i l i z a t i o n of body energy s t o r e s over w i n t e r  ( F i g . 10,11).  Foda (1974) a l s o observed c o n s t a n t  l i p i d i n A t l a n t i c salmon d u r i n g w i n t e r . combined w i t h low water temperature was  protein  and  Thus the low w i n t e r f e e d i n g r a t e enough t o meet m e t a b o l i c  demand and  l i t t l e else. There were two  time p e r i o d s d e m o n s t r a t i n g s i g n i f i c a n t changes i n  proximate composition.  The  f i r s t of these was  d u r i n g the e a r l y f r y stage  when w i l d coho f r y l i p i d d e c r e a s e d s h a r p l y w h i l e c u l t u r e d f r y i n c r e a s e d i n lipid.  I t appears t h a t w i l d coho are u t i l i z i n g a l l a v a i l a b l e energy s t o r e s  37  for  growth and m e t a b o l i c needs w h i l e c u l t u r e d coho, f e d a l a r g e r r a t i o n ,  are able to s t o r e l i p i d .  The o t h e r time p e r i o d i n which p r o x i m a t e composi-  t i o n was a l t e r e d was d u r i n g s m o l t i f i c a t i o n .  I n t h i s study, l i p i d  content  decreased from F e b r u a r y t o A p r i l f o r two o f t h e t h r e e Qualicum coho groups, but then i n c r e a s e d from A p r i l t o May ( F i g . 1 1 ) . M o i s t u r e d e c l i n e d s h a r p l y for  a l l t h r e e groups.  Changes i n p r o x i m a t e c o m p o s i t i o n  vary w i t h the f i s h species.  during  smolting  Foda (1974) o b s e r v e d a d e c l i n e i n l i p i d and  m o i s t u r e b u t an i n c r e a s e i n p r o t e i n f o r h a t c h e r y A t l a n t i c salmon.  Andersen  and Narver (1975) n o t e d a d e c l i n e i n w i l d coho l i p i d from F e b r u a r y t o A p r i l and then an i n c r e a s e t o May.  I n w i l d masu salmon, t h e l i p i d  content  i n c r e a s e d from March t o A p r i l and then d e c l i n e d t o May (Ota and Yamada 1974a).  I n hatchery  steelhead, l i p i d declined f o r smaller smolts, while  b o t h p r o t e i n and l i p i d d e c l i n e d i n l a r g e r s m o l t s  ( F e s s l e r and Wagner 1969).  I n c h i n o o k salmon no changes i n p r o x i m a t e c o m p o s i t i o n were observed d u r i n g s m o l t i n g (Woo e_t a l . 1978) . i n body l i p i d d u r i n g  The most f r e q u e n t o b s e r v a t i o n was a d e c r e a s e  smolting.  Hoar (1976) d i s c u s s e d s e v e r a l e x p l a n a t i o n s f o r t h e d e c r e a s i n g content during s m o l t i n g , i n c l u d i n g :  adaptation to a hyperosmotic e n v i r o n -  ment, i n c r e a s e d m e t a b o l i s m , and i n c r e a s e d growth w i t h a c h a n n e l i n g into protein.  L i p i d content  d i e t a r y energy i n t a k e .  lipid  o f energy  d u r i n g s m o l t i n g w i l l a l s o be i n f l u e n c e d by  I f energy i n t a k e i s lower  than m e t a b o l i c demand,  l i p i d stores w i l l decline. C.  P h o s p h o l i p i d Content  As t h e crude c o n t e n t content hatchery  i n f i s h t i s s u e increased, the p h o s p h o l i p i d  (%) d e c r e a s e d (Table 3 ) . The w i l d coho were h i g h e r than t h e coho i n p h o s p h o l i p i d ( p e r c e n t o f crude l i p i d ) . Oh' a wet t i s s u e  38  b a s i s ; however, p h o s p h o l i p i d c o n t e n t was s i m i l a r i n w i l d and h a t c h e r y Thus, the d i f f e r e n c e s i n p h o s p h o l i p i d c o n t e n t  fish.  (%) were due t o v a r i a t i o n s  i n some o t h e r component o f t h e crude l i p i d such as t r i a c y l g l y c e r o l . On a wet t i s s u e b a s i s , p h o s p h o l i p i d s were a l s o found t o be s i m i l a r i n w i l d and h a t c h e r y p l a i c e (Owen e t a l . 1972).  However, Cowey e t a l . (1974)  n o t e d a h i g h e r p h o s p h o l i p i d c o n t e n t i n c u l t u r e d p l a i c e , w h i l e Ota and Yamada (1974b) observed  a lower p h o s p h o l i p i d c o n t e n t i n c u l t u r e d masu salmon.  P h o s p h o l i p i d s e x i s t p r i m a r i l y as s t r u c t u r a l components o f b i o l o g i c a l membranes and a r e n o t thought 1974).  t o be s t o r e d i n s i g n i f i c a n t amounts (Shul'man  Thus, d i f f e r e n c e s . b e t w e e n h a t c h e r y and w i l d f i s h a r e s u r p r i s i n g .  The p o s s i b i l i t y of a s t o r e o f p h o s p h o l i p i d f o r as y e t unknown purposes remains t o be e x p l o r e d . D.  F a t t y A c i d Content  I n b o t h coho and s t e e l h e a d , p o l a r l i p i d s were much h i g h e r than n e u t r a l l i p i d s i n p o l y u n s a t u r a t e d and o>3 f a t t y a c i d s .  Fish o i l s , specifically  fish  p h o s p h o l i p i d s , a r e known t o be r i c h i n p o l y u n s a t u r a t e d f a t t y a c i d s (Lee and Sinnhuber  1972) .  The h i g h c o n t e n t o f these f a t t y a c i d s i n p h o s p h o l i p i d i s  p r i m a r i l y due t o t h e c o n t e n t o f 22:6o)3.  Although polyunsaturated  fatty  a c i d s a r e h i g h e r i n p h o s p h o l i p i d than t r i a c y l g l y c e r o l , the p o s i t i o n o f the f a t t y a c i d s i n these l i p i d s i s s i m i l a r .  B r o c k e r h o f f e t a l . (1963) found  t h a t 0)3 f a t t y a c i d s were p r e f e r e n t i a l l y bound i n the (3 p o s i t i o n f o r b o t h p h o s p h o l i p i d and t r i a c y l g l y c e r o l .  The r e s u l t a n t (3-monoacylglycerol was a  s t a b l e s t r u c t u r e and a means t o p r e s e r v e t h e p o l y u n s a t u r a t e d f a t t y a c i d s from o x i d a t i o n . However, as n o t e d i n t h e r e v i e w o f l i p i d metabolism,  at  l e a s t some o f the t r i a c y l g l y c e r o l s a r e c o m p l e t e l y d i g e s t e d t o f a t t y a c i d b e f o r e a b s o r p t i o n by f i s h .  The h i g h c o n t e n t o f p o l y u n s a t u r a t e d f a t t y a c i d s  39  i n p h o s p h o l i p i d i s no doubt r e l a t e d t o t h e s t r u c t u r a l r o l e o f p h o s p h o l i p i d s i n b i o l o g i c a l membranes. Most o f t h e o)6 f a t t y a c i d s were i n t h e .form o f 18:2o>6 w h i l e t h e o>3 f a t t y a c i d s e x i s t e d as 20:5o)3 and 22;6o>3. the pen-reared than 20:4o)6.  T h i s was e s p e c i a l l y e v i d e n t i n  s t e e l h e a d where t h e c o n t e n t o f 18:2o>6 was v e r y much h i g h e r As d i s c u s s e d i n t h e r e v i e w of l i p i d m e t a b o l i s m ,  c h a i n e l o n g a t i o n i n pen-reared  the l a c k of  co6 f a t t y a c i d s may be a r e s u l t of c o m p e t i t i o n  w i t h 0)3 f a t t y a c i d s f o r enzyme s i t e s . In  coho, t h e g r e a t e s t d i f f e r e n c e s i n f a t t y a c i d c o n t e n t were i n t h e  neutral l i p i d fractions.  W i l d smolts were h i g h e r i n co3 f a t t y a c i d s b u t  lower i n o>6 f a t t y a c i d s . P r o d u c t i o n  and r e a r i n g - c h a n n e l coho were c h a r a c t e r -  i z e d by h i g h e r amounts o f 18:2CJ6, 20:lo)9, and 22:loi9, w h i l e on a p e r c e n t b a s i s , t h e w i l d s m o l t s were h i g h e r i n 22:6u>3 c o n t e n t . d i f f e r e n c e s were apparent  In steelhead,  i n b o t h n e u t r a l and p o l a r l i p i d .  Pen-reared  s m o l t s Were much h i g h e r i n 18:2o>6 w h i l e w i l d smolts were h i g h e r i n oi3 f a t t y acids.  The c o n t e n t of 22:6cu3 was much g r e a t e r i n w i l d smolt n e u t r a l l i p i d .  R e l i a b l e comparisons o f f a t t y a c i d c o n t e n t i n w i l d and h a t c h e r y salmonids have been made o n l y f o r masu salmon (Ota and Yamada 1974b).  The  r e s u l t s were s i m i l a r t o t h i s study w i t h t h e c u l t u r e d masu h i g h e r i n 0)6 f a t t y a c i d s and t h e w i l d masu h i g h e r i n o)3 f a t t y a c i d s . Comparisons f o r o t h e r s p e c i e s o f salmonids  are sadly l a c k i n g .  F a t t y a c i d c o n t e n t i s s t r o n g l y i n f l u e n c e d by d i e t .  The g r e a t e r o>3  f a t t y a c i d c o n t e n t i n w i l d coho was a r e f l e c t i o n o f t h e 0)3 f a t t y c o n t e n t i n a q u a t i c i n s e c t s ( T a b l e 12).. v e r y h i g h i n 20:lo)9 and 22:lo)9.  acid  The Oregon M o i s t P e l l e t d i e t was  The o i l source f o r t h i s d i e t i s l i k e l y a  marine type as marine f i s h such as h e r r i n g a r e known t o be h i g h i n 20:loi9  40  and 22:1CJ9 (16.1%,  19.8%,. r e s p e c t i v e l y ) (Cowey and Sargent 1972).  S i l v e r Cup d i e t was v e r y h i g h i n CJ6 f a t t y a c i d s . d i e t i s l i k e l y t o be, a t l e a s t p a r t i a l l y , o i l s a r e h i g h i n o>6 f a t t y a c i d s  (N.R.C.  The  The o i l s o u r c e f o r t h i s  a v e g e t a b l e s o u r c e as v e g e t a b l e 1973).  The i n f l u e n c e o f these d i e t s on the f a t t y a c i d c o n t e n t o f the f i s h much more e v i d e n t i n n e u t r a l l i p i d  than p o l a r l i p i d .  f a t t y a c i d content of the p o l a r l i p i d  was  T h i s i m p l i e s t h a t the  i s t i g h t l y regulated.  .Differences  i n f a t t y a c i d c o n t e n t between d i e t s must be v e r y l a r g e b e f o r e a s i g n i f i c a n t impact w i l l be o b s e r v e d i n p o l a r l i p i d . exception. lipid.  However, co3 f a t t y a c i d s a r e an  F a t t y a c i d s o f t h e u>3 type a r e . p r e f e r e n t i a l l y bound i n p o l a r  T h i s was e s p e c i a l l y e v i d e n t f o r 22:6a>3 where the c o n t e n t i n the  f i s h was much h i g h e r than i n t h e d i e t . Thus d i f f e r e n c e s i n b i o c h e m i c a l c o m p o s i t i o n between w i l d and c u l t u r e d s a l m o n i d s a r e a r e s u l t o f d i f f e r e n c e s i n r a t i o n l e v e l and d i e t c o m p o s i t i o n . By a l t e r i n g r a t i o n s i z e and the f a t t y a c i d c o n t e n t o f d i e t s f e d t o c u l t u r e d f i s h , the l i p i d c o n t e n t o f w i l d f i s h can be matched.  II.  Impact o f Smolt S i z e and B i o c h e m i c a l  Composition  on M a r i n e S u r v i v a l A.  Smolt S i z e  Generally,  i n c r e a s i n g smolt s i z e improves marine s u r v i v a l  1970; Hager and Nobel 1976). increases  However, r e l e a s i n g l a r g e r s m o l t s a l s o  t h e number o f p r e c o c i o u s male r e t u r n s , r e s u l t i n g i n decreased  numbers o f r e t u r n i n g a d u l t s  ( B i l t o n 1978).  A c c o r d i n g t o B i l t o n the  i n f l u e n c e o f s i z e a l s o depends on time o f r e l e a s e . released  (Johnson  I f coho s m o l t s were  i n m i d - A p r i l , the s m a l l e r s m o l t s (8-10 g) gave the b e s t r e t u r n s .  41  I f s m o l t s were r e l e a s e d i n e a r l y June, i t was t h e l a r g e r s m o l t s (19 g) g i v i n g the best r e t u r n s . May,  I n t h i s s t u d y , coho s m o l t s were r e l e a s e d i n l a t e  thus f a v o u r i n g the p r o d u c t i o n - c h a n n e l coho. B.  Proximate  Composition  The i n f l u e n c e o f p r o x i m a t e c o m p o s i t i o n on marine s u r v i v a l has n o t been well investigated.  Returns o f c h i n o o k salmon were improved where s m o l t s  were r e l e a s e d w i t h h i g h body p r o t e i n and l i p i d  (Burrows 1969).  Peterson  (1972) i n c r e a s e d A t l a n t i c salmon marine s u r v i v a l by f e e d i n g a d i e t c o n t a i n ing  16% marine o i l .  I t was n o t e v i d e n t from t h i s study i f t h e h i g h e r  s u r v i v a l was a r e s u l t o f i n c r e a s e d body l i p i d o r u)3 f a t t y a c i d s . e a r l i e r , marine o i l s a r e h i g h i n o>3 f a t t y a c i d s .  As n o t e d  Thus, a l t h o u g h h i g h e r  body p r o t e i n would seem t o improve marine s u r v i v a l , t h e impact o f l i p i d i s not c l e a r . lipid  I s i t t h e l i p i d c o n t e n t p e r se o r t h e f a t t y a c i d c o n t e n t o f t h e  t h a t i n f l u e n c e s marine  survival?  I t does seem c l e a r t h a t t h e w i l d - t y p e p r o x i m a t e c o m p o s i t i o n would be d e s i r a b l e i n c u l t u r e d f i s h t o i n c r e a s e t h e i r marine s u r v i v a l .  Wood e t a l .  (1960) r e l e a s e d h a t c h e r y coho salmon i n t o a stream a f t e r h a v i n g r e a r e d t h e f i s h f o r between t h r e e and t w e l v e months.  Coho r e a r e d i n t h e h a t c h e r y f o r  t h r e e t o s i x months r e q u i r e d o n l y t h r e e months t o r e v e r t t o t h e w i l d - t y p e p r o x i m a t e c o m p o s i t i o n o f low body l i p i d .  F i s h r e l e a s e d i n t o t h e stream  a f t e r n i n e t o t w e l v e months o f h a t c h e r y r e a r i n g d i d n o t make t h e c o n v e r s i o n to  t h e w i l d - t y p e c o m p o s i t i o n b e f o r e s m o l t i n g a t f o u r t e e n months and  s u f f e r e d poor ocean s u r v i v a l s . C.  F a t t y A c i d Content  There have been no experiments d e s i g n e d s p e c i f i c a l l y t o i n v e s t i g a t e the i n f l u e n c e o f f a t t y a c i d c o n t e n t on marine s u r v i v a l .  Much r e s e a r c h has  42  been devoted toward d e f i n i n g e s s e n t i a l f a t t y a c i d r e q u i r e m e n t s and t h e i r functions i n f i s h . 1.  Essential Fatty Acids i n Fish  The s u b j e c t o f e s s e n t i a l f a t t y a c i d s i n f i s h was r e c e n t l y r e v i e w e d by C a s t e l l (1979).  F a t t y a c i d s o f t h e o>3 s e r i e s a r e e s s e n t i a l f o r f a v o u r a b l e  s a l m o n i d growth and f o o d c o n v e r s i o n . F o r rainbow t r o u t , t h e e s s e n t i a l a c i d r e q u i r e m e n t i s met by 1.0% 18:3o)3 ( p e r c e n t o f d r y d i e t ) . salmon, t h e r e q u i r e m e n t i s somewhat h i g h e r a t 1.0-2.5%.  fatty  F o r coho  I n rainbow t r o u t ,  l o n g c h a i n u3 f a t t y a c i d s have more e s s e n t i a l f a t t y a c i d a c t i v i t y than 18:3oi3. F a t t y a c i d s o f t h e u>6 s e r i e s a r e n o t a b s o l u t e l y r e q u i r e d f o r growth. When combined w i t h h i g h o>3 f a t t y a c i d s , CJ6 f a t t y a c i d s l e s s than 1.0% ( p e r c e n t o f d r y d i e t ) a r e b e n e f i c i a l f o r t r o u t growth (Yu and Sinnhuber 1976).  I n c r e a s i n g t h e OJ6 f a t t y , a c i d c o n t e n t i n t h e d i e t from 1.0 t o 2.5%  d e c r e a s e d growth r a t e s (Yu and Sinnhuber 1976).  I n coho salmon, co6 f a t t y  a c i d s above 1.0% i n t h e d i e t w i l l i n h i b i t growth (Yu and Sinnhuber 1979). At l e a s t f o r coho salmon, t h e d e c r e a s e i n growth r a t e may be a r e s u l t o f the i n h i b i t i o n by co6 f a t t y a c i d s o f c h a i n e l o n g a t i o n o f o>3 f a t t y a c i d s (Tinsley et a l .  1971).  Warm water f i s h such as c a r p d i f f e r from s a l m o n i d s i n t h e i r f a t t y a c i d requirements.  Carp r e q u i r e b o t h w3 (1.0%) and o>6 (1.0%) f a t t y a c i d s f o r  f a v o u r a b l e growth ( C a s t e l l 1979). To compare t h e e s s e n t i a l f a t t y a c i d l e v e l s i n h a t c h e r y d i e t s t o t h e d i e t a r y r e q u i r e m e n t s suggested above, we must c o n v e r t t h e p e r c e n t c o n t e n t of f a t t y a c i d s i n t h e d i e t a r y o i l t o a p e r c e n t a g e o f t h e d r y w e i g h t o f t h e diet.  Thus, we s h a l l assume t h a t 75% o f t h e w e i g h t o f t h e o i l i s made up  43  of  fatty acids.  T h i s i s a c o n s e r v a t i v e e s t i m a t e based on l i p i d  c l a s s to  f a t t y a c i d w e i g h t c o n v e r s i o n f a c t o r s c a l c u l a t e d by C h r i s t i e (1973).  For  Oregon M o i s t P e l l e t , t h e c o n t e n t o f oi3 and o>6 f a t t y a c i d s ( p e r c e n t o f t h e dry  w e i g h t ) was 2.2% and 0.7% r e s p e c t i v e l y .  F o r S i l v e r Cup, t h e c o n t e n t  of o)3 f a t t y a c i d s was 2.6%, and 1.9% f o r t h e 0)6 f a t t y a c i d s .  The d i e t a r y  0)3 f a t t y a c i d r e q u i r e m e n t s f o r s a l m o n i d s would be met by b o t h o f t h e s e diets.  Based on t h e work o f Yu and Sinnhuber (1976, 1979) , t h e 0)6 f a t t y  a c i d c o n t e n t of t h e h a t c h e r y d i e t s , as f e d i n t h i s s t u d y i n a d e p r e s s i o n of f i s h growth.  would n o t r e s u l t  The S i l v e r Cup d i e t would l i k e l y  depress  growth i f f e d t o coho salmon s i n c e coho cannot t o l e r a t e as h i g h a d i e t a r y 0)6 f a t t y a c i d c o n t e n t as rainbow t r o u t . 2.  F a t t y A c i d Content and Membrane and L i p i d F u n c t i o n  F a t t y a c i d s a r e i m p o r t a n t s t r u c t u r a l components o f b i o l o g i c a l membranes. I t was observed some y e a r s ago t h a t t h e i o d i n e number f o r l i p i d  extracted  from g o l d f i s h i n c r e a s e d as w a t e r temperature d e c r e a s e d (Hoar and C o t t l e 1952).  The i o d i n e number i s a measure o f the degree o f s a t u r a t i o n i n l i p i d  f a t t y a c i d s such t h a t t h e h i g h e r t h e i o d i n e number t h e more u n s a t u r a t e d t h e fatty acids.  I n c r e a s i n g t h e u n s a t u r a t i o n of t h e f a t t y a c i d s would l o w e r  t h e i r m e l t i n g p o i n t and r e t a i n t h e f l u i d i t y o f the membrane.  Hazel  (1979a)  i d e n t i f i e d t h e s p e c i f i c f a t t y a c i d s t h a t were, a l t e r e d i n p h o s p h o l i p i d s from rainbow t r o u t l i v e r as w a t e r temperature d e c r e a s e d .  The i n c r e a s i n g u n s a t u r -  a t i o n was p r i m a r i l y a r e s u l t o f o>3 f a t t y a c i d s (22:6o)3).  I n c a t f i s h whole  l i p i d , b o t h 0)3 and 0)6 f a t t y a c i d s were i n v o l v e d i n temperature a d a p t a t i o n (Andrews and S t i c k n e y 1972). F a t t y a c i d u n s a t u r a t i o n i s n o t t h e o n l y a l t e r a t i o n made t o membrane s t r u c t u r e w i t h water temperature changes.  Wodtke (1978) n o t e d a d e c r e a s e  44  i n t h e molar r a t i o o f c h o l e s t e r o l and p h o s p h o l i p i d i n l i v e r m i t o c h o n d r i a l membranes from c a r p , r e a r e d a t low water t e m p e r a t u r e s .  The decreased  c h o l e s t e r o l / p h o s p h o l i p i d r a t i o i n c r e a s e d the s u s c e p t i b i l i t y o f p h o s p h o l i p i d s to  f l u i d i t y c o n t r o l by f a t t y a c i d s . F u r t h e r s u p p o r t f o r t h e importance o f o>3 f a t t y a c i d s i n membrane  s t r u c t u r e has come from t h e work o f C a s t e l l e t a l . (1972). m i t o c h o n d r i a were suspended  i n a 0.25 M s u c r o s e s o l u t i o n .  Rainbow t r o u t M i t o c h o n d r i a from  f i s h f e d a l i n o l e n i c a c i d (18:3o>3) d i e t had t h e l o w e s t s w e l l i n g r a t e .  A  l i n o l e i c a c i d (18:2ai6) d i e t a l s o reduced t h e s w e l l i n g r a t e over t h e f a t - f r e e d i e t , but was n o t as e f f e c t i v e as t h e l i n o l e n i c a c i d  diet.  N e u t r a l l i p i d a l s o e x h i b i t s changes i n f a t t y a c i d c o n t e n t w i t h temperature.  Monounsaturated  (20:lo)9), 0)3 (22:6w3) and. o)6 (20:4oi6) f a t t y  a c i d s i n c r e a s e d i n c o n t e n t a t low water temperatures ( H a z e l 1979b). Presumably, t h e change i n u n s a t u r a t i o n f o r n e u t r a l l i p i d a l t e r s t h e s t a t e of  t h e l i p i d e n s u r i n g i t s a v a i l a b i l i t y f o r use as an energy s t o r e .  Thus,  0)3 f a t t y a c i d s a r e i m p o r t a n t f o r temperature a d a p t a t i o n i n b o t h n e u t r a l and polar  lipid. 3.  Docosahexaenoic A c i d (22: 6o)3)  Docosahexaenoic  a c i d has a s p e c i a l r o l e i n f i s h l i p i d .  I t i s t h e most  u n s a t u r a t e d f a t t y a c i d found i n f i s h l i p i d and thus i s o f g r e a t importance i n temperature a d a p t i o n . As w e l l , f i s h eggs a r e h i g h i n 22:6oi3 c o n t e n t (Nakagawa and T s u c h i y a 1978; Schauer and Simpson 1978).  In carp, i f the  22:6o>3 c o n t e n t o f t h e egg was decreased below 10.0% t h e h a t c h a b i l i t y o f t h e eggs was reduced (Shimma e t a l . 1977).  Rainbow t r o u t s a c - f r y  selectively  r e t a i n e d 22:6oi3 i n t h e t i s s u e s , a t t e s t i n g t o t h e s t r u c t u r a l r o l e p l a y e d by t h i s f a t t y a c i d (Hayes e t a l . 1973).  S e v e r a l a u t h o r s have s p e c u l a t e d t h a t  45  22:6w3 has a r e g u l a t o r y r o l e on body l i p i d c o n t e n t ; however, c o n c l u s i v e e v i d e n c e i s n o t y e t a v a i l a b l e (Owen e t a l , 1972; Schauer and Simpson 4.  1978).  F a t t y A c i d Requirements i n F r e s h and S a l t Water  The e s s e n t i a l f a t t y a c i d r e q u i r e m e n t s o f s a l m o n i d s have been measured o n l y i n t h e f r e s h w a t e r environment.  I n A t l a n t i c salmon, t h e groups t h a t  grew b e s t i n f r e s h w a t e r were n o t n e c e s s a r i l y t h o s e t h a t d i d b e s t i n s a l t w a t e r (Gunnes and Gjedrom 1978; R e f s t i e and S t e i n e 1978; R e f s t i e , p e r s o n a l communication).  Thus, a t l e a s t f o r growth, t h e r e q u i r e m e n t s i n s a l t water  were d i s t i n c t i v e . F a t t y a c i d s o f t h e u>3 s e r i e s a r e much h i g h e r i n marine f i s h 1979).  (Castell  Ayu c o l l e c t e d i n t h e sea were h i g h e r i n o>3 f a t t y a c i d s than t h o s e  c o l l e c t e d from a l a k e (Ota and T a k a g i 1977). the same.  I n s a l m o n i d s , t h e r e s u l t was  As j u v e n i l e masu s m o l t s m i g r a t e d from f r e s h water t o s a l t water  the o)6/u)3 r a t i o d e c r e a s e d (Ota 1976).  I t i s n o t c l e a r whether t h e h i g h o>3  f a t t y a c i d c o n t e n t i n marine f i s h i s a d i e t a r y r e s p o n s e , o r a p h y s i o l o g i c a l r e q u i r e m e n t f o r t h e s a l t w a t e r environment.  The work o f L a l l and B i s h o p  (1975) s u g g e s t s i t i s a t l e a s t p a r t l y a p h y s i o l o g i c a l r e q u i r e m e n t .  These  a u t h o r s n o t e d a h i g h e r m o r t a l i t y i n s a l t water than f r e s h water f o r rainbow t r o u t f e d an o>6 f a t t y a c i d d i e t .  Thus, t h e requirement f o r u)3 f a t t y a c i d s  i n s a l t w a t e r i s l i k e l y t o be g r e a t e r than i n f r e s h w a t e r . The h i g h c o n t e n t o f 22:lo>9 (17.8%) i n Oregon M o i s t P e l l e t f e d f i s h r e q u i r e s f u r t h e r comment.  T a k a g i (1978) r e p o r t e d t h a t r a t s f e d d i e t s h i g h  i n 22:1 demonstrated a d e c r e a s e d growth r a t e and c a r d i a c damage.  This  f a t t y a c i d i s l e g a l l y r e s t r i c t e d t o l e s s than 5.0% o f t h e d i e t a r y f a t i n d i e t s f o r human consumption ( T a k a g i 1978), a l e v e l much lower than t h a t p r e s e n t i n Oregon M o i s t P e l l e t .  The i n f l u e n c e o f t h i s f a t t y a c i d on t h e  46  marine s u r v i v a l of Oregon M o i s t P e l l e t f e d f i s h i s f i s h such as h e r r i n g (Cowey and Sargent 1972)  unknown.  a r e h i g h i n 22:1  suggests a b a s i c d i f f e r e n c e i n f i s h and mammal l i p i d  III.  That marine content  metabolism.  C o n c l u d i n g Remarks As compared to the w i l d coho, p r o d u c t i o n - c h a n n e l coho were c h a r a c t e r -  i z e d by h i g h body l i p i d and low m o i s t u r e . m o s t l y i n the n e u t r a l l i p i d f r a c t i o n .  F a t t y a c i d content d i f f e r e d  P r o d u c t i o n - c h a n n e l coho, on a  p e r c e n t b a s i s , were h i g h e r i n o>6 f a t t y a c i d s and lower i n o>3 f a t t y a c i d s , than the w i l d coho.  R e a r i n g - c h a n n e l coho were i n t e r m e d i a t e i n p r o x i m a t e  c o m p o s i t i o n and o>6 f a t t y a c i d c o n t e n t but were s i m i l a r to the p r o d u c t i o n channel coho i n the u3 f a t t y a c i d c o n t e n t o f n e u t r a l l i p i d . 2.2  W i l d coho had  times the 22:6o)3 c o n t e n t ( n e u t r a l l i p i d ) of the p r o d u c t i o n - c h a n n e l  r e a r i n g - c h a n n e l coho.  Pen-reared  s t e e l h e a d were s i m i l a r to the w i l d  s t e e l h e a d i n p r o t e i n and ash c o n t e n t but were lower i n l i p i d c o n t e n t . f a t t y a c i d c o n t e n t o f b o t h n e u t r a l and p o l a r l i p i d d i f f e r e d i n w i l d pen-reared  steelhead.  Pen-reared  The  and  s t e e l h e a d were much h i g h e r i n o>6 f a t t y  a c i d s but lower i n 0)3 f a t t y a c i d s , than the w i l d s t e e l h e a d . 22:6o)3 i n w i l d s t e e l h e a d n e u t r a l l i p i d was pen-reared  and  almost 2.7  The c o n t e n t o f  times t h a t o f the  steelhead.  There i s no doubt t h a t e s s e n t i a l f a t t y a c i d d e f i c i e n t f i s h  will  s u f f e r poor marine s u r v i v a l ; however, none of the f i s h i n t h i s study a r e deficient i n fatty acids. s p e c i f i c a l l y 22:6o)3 o)6 f a t t y a c i d s .  I:; have suggested  are more i m p o r t a n t f o r temperature  As w e l l , the requirement  h i g h e r i n t h e sea.  t h a t oi3 f a t t y a c i d s , a d a p t a t i o n than the  f o r oi3 f a t t y a c i d s i s p r o b a b l y  Thus a h i g h e r OJ3 c o n t e n t i s l i k e l y t o improve m a r i n e  47  survival.  U n f o r t u n a t e l y , I cannot y e t s t a t e whether the d i f f e r e n c e s i n  p r o x i m a t e c o m p o s i t i o n and f a t t y a c i d . c o n t e n t i n the w i l d and h a t c h e r y  fish  i n t h i s s t u d y a r e l a r g e enough to i n f l u e n c e the marine s u r v i v a l of hatchery f i s h .  The s p e c i f i c b i o c h e m i c a l r e q u i r e m e n t s f o r s a l m o n i d s ,  m i g r a t i n g to the sea, a r e unknown.  C e r t a i n l y , u n t i l these r e q u i r e m e n t s  are  i d e n t i f i e d , the b e s t approach would be t o match the b i o c h e m i c a l c o m p o s i t i o n of w i l d  salmonids.  T h e r e f o r e , i t would be a p p r o p r i a t e t o suggest a d d i t i o n a l a r e a s o f research.  The o p t i m a l f a t t y a c i d c o n t e n t f o r s e a - g o i n g salmonids must be  i d e n t i f i e d as i t i s l i k e l y t h a t f r e s h water and s a l t water differ.  requirements  The i n f l u e n c e o f f a t t y a c i d c o n t e n t on marine s u r v i v a l can be  i d e n t i f i e d by m o n i t o r i n g a d u l t r e t u r n s o f s m o l t s f e d d i e t s v a r y i n g i n o>3 and 0)6 f a t t y  acids.  43  BIBLIOGRAPHY Ackman, R. G. 1963. An a n a l y s i s o f s e p a r a t i o n f a c t o r s a p p l i c a b l e i n t h e g a s - l i q u i d chromatography o f u n s a t u r a t e d f a t t y a c i d m e t h y l e s t e r s on a p o l y e s t e r s u b s t r a t e . J . Am. O i l Chem. Soc. 40: 564-567. Andersen, B. L., and D. W. N a r v e r . 1975. F i s h p o p u l a t i o n s o f C a r n a t i o n c r e e k and o t h e r B a r k l e y Sound streams - 1974: d a t a r e c o r d and p r o g r e s s r e p o r t . F i s h . Res. Board Can. M.S. Rept. 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Dunn. 1973. S t a b l e r e a g e n t s f o r d e t e r m i n a t i o n o f serum t r i g l y c e r i d e s by a c o l o r i m e t r i c H a n t z s c h c o n d e n s a t i o n method. C l i n . Chem. 19: 338-340. Gonsolus, R. T. 1978. The s t a t u s o f Oregon coho and recommendations f o r managing t h e p r o d u c t i o n , h a r v e s t , and escapement o f w i l d and h a t c h e r y r e a r e d s t o c k s . Oregon Dept. F i s h . W i l d l . , Columbia R e g i o n , 59 p. G r i f f i o e n , W., and D. W. N a r v e r . 1974. A n o t e on w i n t e r s t a r v a t i o n and f e e d i n g o f c u l t u r e d j u v e n i l e coho salmon. F i s h . Mar. Serv. Tech. Rept. No. 501. Gunnes, K., and T. Gjedrem. 1978. S e l e c t i o n e x p e r i m e n t s w i t h salmon IV. Growth o f A t l a n t i c salmon d u r i n g two y e a r s i n the s e a . A q u a c u l t u r e 15: 19-33. Hager, R. C., and R. E. N o b l e . 1976. 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Verh. I n t e r n a t . V e r e i n . L i m n o l . 20: 2013-2018. Nakagawa, H., and Y. T s u c h i y a . 1976. S t u d i e s on rainbow t r o u t egg (Salmo g a i r d n e r i i r i d e u s ) V I . Changes o f l i p i d c o m p o s i t i o n i n y o l k d u r i n g development. J . F a c . F i s h . Anim. Husb. H i r o s h i m a U n i v . 15: 35-46. N.R.C. 1973. N u t r i e n t r e q u i r e m e n t s o f t r o u t , salmon, and c a t f i s h . N a t i o n a l R e s e a r c h C o u n c i l (U.S.), N a t i o n a l Academy o f S c i e n c i e s , Washington, D. C. 57 p. Ogino, C , J . Y. C h i o u , and T. T a k e u c h i . 1976. P r o t e i n n u t r i t i o n i n f i s h VI E f f e c t s o f d i e t a r y energy s o u r c e s on t h e u t i l i z a t i o n o f p r o t e i n by rainbow t r o u t and c a r p . B u l l . Jap. Soc. S c i . F i s h e r i e s 36: 250-254.  52  Ota, T. 1976. L i p i d s o f masu salmon - IV. 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S t e i n e . 1978. S e l e c t i o n experiments w i t h salmon. III. G e n e t i c and e n v i r o n m e n t a l s o u r c e s o f v a r i a t i o n i n l e n g t h and weight o f A t l a n t i c salmon i n t h e f r e s h w a t e r phase. A q u a c u l t u r e 14: 221-234.  53  Robinson, J . S., and J . F. Mead. 1973. L i p i d a b s o r p t i o n and d e p o s i t i o n i n rainbow t r o u t (Salmo g a i r d n e r i ) . Can. J . Biochem. 51: 1050-1058. Schauer, P. S., and K. L. Simpson. 197.8. L i p i d metabolism and f a t t y c o m p o s i t i o n o f w i l d and c u l t u r e d A t l a n t i c s i l v e r s i d e s ( M e n i d i a menidia). (unpublished data).  acid  Shimma, Y., R. S u z u k i , M. Yamaguchi, and T. Akiyama. 1977. On t h e l i p i d s of a d u l t c a r p s r a i s e d on f r e s h meal and SCP f e e d s , and h a t c h a b i l i t i e s o f t h e i r eggs. B u l l . Freshwater F i s h . Res. Lab. 27: 35-48. S h u l ' m a n . G. E. 1974. 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E v a l u a t i o n o f i n s t r e a m enhancement s t r u c t u r e s f o r t h e p r o d u c t i o n o f j u v e n i l e s t e e l h e a d t r o u t and coho salmon i n t h e Keogh r i v e r ; P r o g r e s s 1977 and 1978. B. C. F i s h and W i l d l i f e B r . , F i s h . Tech. C i r c . 45, 47 p. Wodtke, E. 1978. L i p i d a d a p t a t i o n i n l i v e r m i t o c h o n d r i a l membranes o f carp a c c l i m a t e d t o d i f f e r e n t e n v i r o n m e n t a l temperatures. Biochimica. et B i o p h y s i c a . A c t a 529: 280-291. Woo, N. Y. S., H. A. B e r n , and R. S. N i s h i o k a . 1978. Changes i n body c o m p o s i t i o n a s s o c i a t e d w i t h s m o l t i f i c a t i o n and premature t r a n s f e r t o seawater i n coho salmon (Oncorhynchus k i s u t c h ) and k i n g salmon (0. t s h a w y t s c h a ) . J . F i s h . B i o l . 13: 421-428. Wood, E. M. , W. Y. Y a s u t a k e , J . E. H a l v e r , and A. N. W o o d a l l . 1960. Chemical and h i s t o l o g i c a l s t u d i e s o f w i l d and h a t c h e r y salmon i n f r e s h water. Trans. Am. F i s h . Soc. 89: 301-307. Wood, E. M., W. T. Y a s u t a k e , A. N. W o o d a l l , and J . E. H a l v e r . 1957. The n u t r i t i o n o f salmonid f i s h e s . I . Chemical and h i s t o l o g i c a l s t u d i e s of w i l d and domestic f i s h . J . N u t r . 61: 465-478. Yu, T. C , and R. 0. Sinnhuber. 1976. Growth response o f rainbow t r o u t (Salmo g a i r d n e r i ) t o d i e t a r y 0)3 and w6 f a t t y a c i d s . A q u a c u l t u r e 8: 309-317.  54  Yu, T. C , and R. 0. Sinnhuber. 1979. E f f e c t of d i e t a r y <D3 and w6 f a t t y a c i d s on growth and food c o n v e r s i o n e f f i c i e n c y o f coho salmon (Oncorhynchus k i s u t c h ) . A q u a c u l t u r e 16: 31-38.  55  Table 1.  R e a r i n g c o n d i t i o n s i n the Qualicum, C a p i l a n o , and Keogh r i v e r study a r e a s .  Qualicum  Production-  Length  Width  Water  (m)  Rearing-  (m)  Natural  Burrows  river  Natural  Keogh  Pen  channel  275  396  46  4.6  4.6  2.4  3.3  0.9  4.6  1.0  Mean annual water temperature  Capilano  channel  (m)  depth  river  pool ri f f l e  8.6  Natural  pond  0.9 0.15  7.5  8.7  O 10.1  8.8  Cc) Water  flow  (m  /min)  Water velocity (m/min)  Number of released  4.2  fish  Total weight of fish at release (kg)  Fish Density at r e l e a s e (kg/m  34  3  « '  24  pool r i f f l e  5.8 34.8  425  1.7  0.8  615,242  63,000  75,000  3,000  12,403.0  743.4  1383.8  192.  1.9  13.9  5.6  river  2.8  3  57  T a b l e 2.  F o r k l e n g t h , wet weight and c o n d i t i o n f a c t o r o f coho salmon and steelhead trout.  V a l u e s a r e means w i t h 95% c o n f i d e n c e l i m i t s .  Groups w i t h t h e same s u p e r s c r i p t form a homogeneous subset (ANOVA, S c h e f f e ' s t e s t , p_<0.05).  Groups from d i f f e r e n t l i f e h i s t o r y s t a g e s  and r i v e r systems a r e a n a l y s e d s e p a r a t e l y .  58  Sampling  Wet Rearing  No. o f f i s h  Fork l e n g t h  method  sampled  (mm)  weight (g)  Condition  date  factor  1979  Qualicum coho  Natural  presmolt  Production channel  61  69.8 + 2 . 5  a  40  101.4 + 2 . 7  b  50  88.4 + 1 . 9  C  38  101.2 + 4 . 0  a  11.63  30  117.7 + 2 . 9  b  17.46  40  99.6 + 2.3  3.74 + 0.43  a  6.44 + 0 . 2 1  a  April  b  5.97 + 0 . 1 3  b  A p r i 1 9"  c  6.08 + 0 . 1 1  b  April 9  + 1.14  a  6.05 + 0.15  a  May 31  + 1.45  b  5.61 + 0 . 2 5  b  May 14  a  11.80 + 0 . 8 1  a  6.70 + 0 . 1 5  C  May 17  5.36 + 0.14  11.47 +  l.ll  2  Rearingchannel  7.35 + 0.46  Qualicum coho  Natural  smolt  Productionchannel Rearingchannel  Capilano coho  Natural  31  110.6  + 7.0  a  14.60 + 3.00  a  smolt  Hatchery  20  123.8 + 4 . 3  b  18.45  + 1.97  a  steelhead  Natural  20  182.8 + 9 . f l  a  60.7  +10.16  smol t  Pen  20  187.6  a  64.1  + 7.73  a  5.11 + 0.16  b  June 1 June 5  Keogh  +9.0  b  b  4.64 + 0.30  a  May 16  4.59 + 0.19  a  May 10  59  Table 3.  Whole body p r o x i m a t e c o m p o s i t i o n (% wet t i s s u e ) and p h o s p h o l i p i d c o n t e n t o f coho salmon and s t e e l h e a d t r o u t . 95% c o n f i d e n c e l i m i t s .  Values a r e means w i t h  Groups w i t h t h e same s u p e r s c r i p t form a  homogeneous subset (ANOVA, S c h e f f e ' s t e s t , pj<0.05).  Groups from  d i f f e r e n t l i f e h i s t o r y s t a g e s and r i v e r systems a r e a n a l y s e d separately.  Proximate composition {% wet tissue)  X of crude lipid  Phospholipid (mg) g wet tissue  1.78 • 0.37*  65.0 • 4.5*  11.6 1 2.3*  b 14.7 • 0.5  b 4.27 • 0.60  31.2 + 3.7  13.0  2.63 • 0.22*  b 14.8 + 0.3  2.78 • 0.25  C  42.9 • 3.5°  11.8 +0.8*  79.1 • 1.1*  2.58 • 0.21*  16.2 + 0.6*  3.02 • 0.60*  41.7 • 8.0*  11.8 +0.5*  3  76.3 • 0.5  2.53 • 0.2l"  15.6 • 0.3*  4.41 • 0.41  28.1 • 2.4  12.2 +0.4*  10  4  79.1 + 0.3*  2.51 • 0.12*  14.5 +  O.^  3.20 • 0.19*  42.3 • 1.7*  13.5 +0.6  Natural  11  2-4  79.7 • 0.3*  254 • 0.20*  16.2 • 0.5*  2.05 • 0.16*  68.5 • 4.2*  13.8 +0.7*  Hatchery  10  2  77.3 •  O.SP  2.53 • 0.30*  16.1 • 0.3*  3.81 • 0.62  36.9 • 6.5  13.4 • 1.0*  Natural  10  2  76.2 • 1.0*  2.49 • 0.27*  16.5 • 0.4*  22.8 • 4.4*  9.0 • 0.6*  Pen  10  2  76.6 + 0.7*  2.71 • 0.36*  17.0 •  4.19 • 0.84* b 2.93 • 0.16  31.9 • 1.6  9.3 +0.2*  Rearing method  No. fish per sample  Moisture  Ash  Protein  6  10  81.6 + 0.6*  2.79 • 0-43*  13.9 + 0.5*  10  4  b 77.5 • 1.0  2.48 • 0.18*  10  5  79.4 • 0.4°  Natural  10  4  Production channel  10  Rearing channel Capilano coho smolt  Qualicum coho presmolt  smolt  Keogh steelhead smolt  No. samples  Natural Production channel Rearing channel  Qualicum coho  Phospholipid content  ....  6  Lipid  O.i  b  b  b  b  5  +1.2* O O  61  T a b l e 4.  Whole body p r o x i m a t e c o m p o s i t i o n (% d r y t i s s u e ) of coho salmon and steelhead trout.  V a l u e s a r e means w i t h 95% c o n f i d e n c e l i m i t s .  Groups w i t h t h e same s u p e r s c r i p t form a homogeneous s u b s e t (ANOVA, S c h e f f e ' s t e s t , p_<0.05).  Groups from d i f f e r e n t l i f e h i s t o r y s t a g e s  and r i v e r systems a r e a n a l y s e d s e p a r a t e l y .  62  Rearing method  No. f i s h No. samples  per sample  Proximate composition (% dry t i s s u e ) Ash  Qualicum coho  Natural  presmolt  Production channel  6  10  15.23 + 2.67  10  4  11.02 +0.61  channel  10  5  12.76 + 0.99  72.00 + 1.80  10  4  12.42 + 1.24*  77.,73 + 4.40  10  3  10.72 + 0.97  10  4  11.99 + 0.52  69.,25 + 1.22  79.92 + 1.75  3  b  Rearing -  b  75.37 + 2.16  65.38 + 3.30  Qualicum coho  Natural  smolt  Production channel  b  Rearing channel  Lipid  Protein  s,b  65..90 + 1.67  Capilano coho  Natural  11  2-4  smolt  Hatchery  10  2  12.54 + 1.09* b 11.14 + 1.13  steelhead  Natural  10  2  10.55 + 1.61 *  69.,44 + 4.13  smolt  Pen  10  2  12.00 + 2.02*  71..23 + 4.15  71.47 + 3.93  Keogh  a  b  9.67 + 1.77  3  b 18.78 + 2.03  a  c 13.45 + 0.97  a  b  b  a b  a a  14.25 + 2.05  3  b 18.59 + 1.41 15.28 + 0.81  3  10.08 + 0.77 b 16.73 + 2.39 3  17.43 + 2.98 b 12.31 + 0.95 3  63  Table 5.  P r o x i m a t e c o m p o s i t i o n o f some a q u a t i c i n s e c t s h a t c h e r y d i e t s (% wet  (% wet  t i s s u e and % dry t i s s u e ) .  tissue)  and  Proximate composition  Moisture  (%)  Ash  Protein  Lipid  Ephemeroptera  -  -  -  6.00  Aquatic  Plecoptera  -  -  -  3.30  insects  Chironomidae Tri choptera  Hatchery  Oregon Pellet  diets  S i l v e r Cup  (  )  Moist  ;  2.44 2.74  30.3  8.88 (12.74)  34.1 ( 4 8 . 9 ) ••'  12.76 (18.31)  6.3  11.27 (12.03)  45.2 (48.2)  12.16 (12.98)  c o n t a i n t h e c o m p o s i t i o n e x p r e s s e d as a % o f t h e d r y t i s s u e  o •  65  T a b l e 6.  F a t t y a c i d c o m p o s i t i o n o f coho s m o l t s r e a r e d n a t u r a l l y i n the Qualicum r i v e r .  V a l u e s a r e means f o r f o u r samples w i t h each  sample c o n s i s t i n g o f f o u r f i s h . £0.005 mg/g.  " T r a c e " i n d i c a t e s _<0.05%,  66 Fatty  Fatty acid composition (2)  Fatty acid (ng/g wet tissue)  acid  Neutral  Polar  Whole  Neutral  Polar  Uhole  type  lipid  lipid  lipid  lipid  lipid  lipid  14:0  2.4  0.4  1.7  0.38  0.03  0.41  14:1  1.0  0.1  0.6  0.14  trace  0.14  15:0  0.5  0.3  0.4  0.07  0.03  0.10  15:1  trace  trace  trace  trace  trace  trace  16:0  13.1  18.2  15.2  2.01  1.66  3.67  16:lu>7  7.4  2.8  5.8  1.14 ^  0.26  1.40  17:0  0.8  0.9  0.9  0.13  0.08  0.21  unknown  0.1  -  0.1  0.02  -  0.02  17:1  0.6  0.2  0.5  0.10  0.02  0.12  18:0  5-1  5.7  5.3  0.76  0.52  1.28  1  18:lu>9  29.5  13.4  24.0  4.57  1.22  5.79  18:2u6  3.8  1.6  2.9  0.55  0.15  0.70  18:3u>6  0.1  trace  trace  0.01  trace  0.01  18:3o)3  2.5  1.4  2.1  0.37  0.13  0.50  20:la)9  1.2  0.2  0.8  0.18  0.02  0.20  18:4u3  1.1  0.3  0.8  0.18  0.03  0.21  20:2u6  0.1  0.1  0.1  0.02  trace  0.02  20:3oi6  trace  0.1  0.1  0.01  0.01  0.02  20:4u6  1.5  3.8  2.4  0.22  0.35  0.57  22:lw9  trace  -  trace  0.01  20:4u>3  1.0  0.4  0.8  0.15  0.03  0.18  20:5u>3  5.5  7.8  6.6  0.87  0.71  1.58  22:3u>6  0.1  -  trace  0.01  22:4u>6  0.1  0.1  0.1  24:lu9  4.1  trace  1.4  22:4u3  -  1.8  0.7  22:5a>3  3.5  3.0  22:6OJ3  14.8  37.1  -  0.01  -  0.01  0.01  0.01  0.02  0.32  trace  0.33  -  0.16  0.16  3.4  0.54  0.27  0.81  23.5  2.28  3.38  5.66  67  Table 7.  F a t t y a c i d c o m p o s i t i o n o f coho s m o l t s r e a r e d i n a p r o d u c t i o n channel.  V a l u e s a r e means f o r f o u r samples w i t h each sample  c o n s i s t i n g of three f i s h .  " T r a c e " i n d i c a t e s _<0.05%, j<0.005 mg/g.  68 Fatty  Fatty acid  composition  (%)  Fatty  a c i d (mg/g wet t i s s u e )  acid  Neutral  Polar  Whole  Neutral  Polar  Whole  type  lipid  lipid  lipid  lipid  lipid  lipid  14:0  4.0  1.1  3.4  1.34  0.10  1.44  14:1  0.2  -  0.1  0.05  -  0.05  15:0  0.2  0.2  0.2  0.08  0.02  0.10  15:1  0.1  trace  0.1  0.03  trace  0.03  16:0  12.1  19.3  13.7  4.04  1.78  5.80  9.0  2.9  7.7  2.99  0.26  3.25  -  0.6  0.2  0.05  0.05  0.10  unknown  0.5  -  0.3  0.11  -  0.11  17:1  0.7  0.2  0.6  0.24  0.01  0.25  18:0  2.5  3.9  2.8  0.84  0.36  1.20  18:1<D9  25.2  11.2  22.2  8.41  1.03  9.44  unknown  trace  -  trace  18:2(j6  7.4  1.7  6.2  2.46  13:3<D6  0.5  -  0.4  0.16  -  0.16  18:3u3  0.6  0.2  0.5  0.18  0.02  0.20  20:lo)9  9.8  1.6  8.0  3.27  0.15  3.42  18:4u)3  0.9  0.1  0.8  0.31  0.01  0.32  20:2u6  0.1  0.1  0.1  0.03  trace  0.03  20:3u6  trace  0.1  0.1  0.02  0.01  0.03  20:4bi6  0.3  1.9  0.6  0.10  0.18  0.28  22:lo)9  9.5  0.4  7.5  3.16  0.03  3.19  20:4u3  -  trace  trace  -  trace  trace  20:5(o3  3.2  6.9  4.0  1.08  0.64  1.72  22:3(D6  0.6  trace  0.5  0.22  trace  0.22.  22:4d)6  0.1  trace  0.1  0.03  trace  0.03  24:lu>9  3.8  1.0  3.1  1.23  0.08  1.31  0.8  0.2  •  -  0.07  0.08  0.6  0.1  -  0.06  0.06  16:lu7 17:0  unknown 22:4w3  -  trace  .  0.16  trace 2.62  unknown  0.7  -  0.5  0.23  -  0.23  22:5ID3  1.5  2.1  1.6  0.49  0.19  0.68  22:6u)3  6.5  43.1  14.5  2.19  3.96  6.15  69  T a b l e 8.  F a t t y a c i d c o m p o s i t i o n o f coho s m o l t s r e a r e d i n a r e a r i n g - c h a n n e l . V a l u e s a r e means f o r f o u r samples w i t h each sample c o n s i s t i n g o f four f i s h .  " T r a c e " i n d i c a t e s £0.05%, £0.005 mg/g.  70 Fatty  Fatty acid composition (%)  Fatty acid (tng/g wet tissue)  acid  Neutral  Polar  Whole  Neutral  Polar  Whole  type  lipid  lipid  lipid  lipid  lipid  lipid  14:0  4.7  1.5  3.6  0.90  0.15  1.05  14:1  0.3  -  0.2  0.06  -  0.06  15:0  0.3  0.2  0.3  0.06  0.02  0.08  15:1  0.1  trace  0.1  0.03  trace  0.03  16:0  12.6  18.5  14.7  2.39  1.94  4.33  16:l(o7  10.6  3.8  8.2  2.01  0.40  2.41  -  0.6  0.2  -  0.05  0.05  unknown  0.5  -  0.3  0.09  -  0.09  17:1  0.8  0.2  0.6  0.15  0.02  0.17  18:0  2.5  4.3  3.2  0.48  0.45  0.93  18:lu>9  22.5  12.7  19.1  4.27  1.33  5.60  unknown  0.2  -  0.1  0.04  -  0.04  18:2o6  6.2  2.3  4.8  1.16  0.24  1.41  18:3u6  0.6  trace  0.4  0.12  trace  0.12  18:30)3  1.0  0.4  0.7  0.18  0.04  0.22  20:lw9  9.7  2.1  7.1  1.86  0.22  2.09  18:4u3  1.8  0.4  1.3  0.34  0.04  0.38  20:2a)6  0.1  0.1  0.1  0.02  0.01  0.03  20:3o6  trace  0.2  0.1  0.01  0.02  0.03  20:4u)6  0.3  2.0  0.9  0.06  0.20  0.26  22:1(D9  11.3  1.0  7.8  2.17  0.11  2.28  20:4a)3  -  0.1  trace  -  0.01  0.01  20:5Q)3  4.1  7.5  5.3  0.78  0.78  1.56  22:3u3  trace  0.1  trace  trace  0.01  0.01  22:4a 6  0.3  0.1  0.2  0.05  0.02  0.07  unknown  1.2  -  0.8  0.23  17:0  1.1  0.4  unknown  -  0.4  22:5u3  1.2  22:6a)3  6.7  22:4(o3  -  0.23  0.12  0.12  0.2  -  0.04  0.04  2.2  1.6  0.23  0.23  0.46  37.7  17.8  1.29  3.94  5.23 !  71  T a b l e 9.  F a t t y a c i d composition o f steelhead smolts reared n a t u r a l l y i n the Keogh r i v e r .  V a l u e s a r e means f o r f o u r samples w i t h each sample  c o n s i s t i n g o f two f i s h .  " T r a c e " i n d i c a t e s <0.05%, <0.005 mg/g.  72 Fatty  Fatty acid composition  (%)  Fatty acid  (mg/g  wet t i s s u e )  acid  Neutral  Polar  Whole  Neutral  Polar  Whole  type  lipid  lipid  lipid  lipid  lipid  lipid  14:0  1.4  0.5  1.2  0.47  0.03  0.50  14:1  0.1  0.2  0.1  0.03  0.01  0.04  15:0  0.2  0.3  0.3  0.09  0.02  0.11  15:1  trace  trace  trace  0.01  trace  0.01  16:0  10.8  17.5  12.1  3.69  1.21  4.90  16:lu7  6.4  2.0  5.6  2.14  0.14  2.28  17:0  0.5  0.9  0.6  0.20  0.04  0.24  17:1  1.0  0.4  0.8  0.32  0.03  0.35  18:0  4.4  6.2  4.8  1.50  0.43  1.93  18:lu9  27.4  12.6  24.9  9.25  0.88  10.13  18:2u6  2.4  0.6  2.0  0.78  0.04  0.82  18:3u>3  1.1  0.3  1.0  0.38  0.02  0.40  20:lu9  1.8  0.4  1.6  0.61  0.03  0.64  18:4w3  0.7  trace  0.6  0.22  trace  0.22  20:2w6  0.2  0.1  0.2  0.06  trace  0.06  20:3u>6  0.1  trace  0.1  0.04  trace  0.04  20:4ID6  1.7  2.6  1.9  0.58  0.18  0.76  22:la)9  0.2  -  0.2  0.07  20:4(D3  2.2  0.6  2.0  0.76  0.04  0.80  20:5(D3  8.2  5.7  7.8  2.77  0.40  3.17  22:3o)6  -  trace  trace  trace  trace  22:4(D6  0.5  0.1  0.5  0.18  0.01  0.19  unknown  1.0  -  0.8  0.32  22:4a)3  -  0.8  0.1  22:5(D3  6.0  2.8  5.4  22:6(D3  21.3  45.0  25.5  .  .  -  -  -  -  0.07  0.32  0.06  0.06  2.00  0.20  2.20  7.22  3.12  10.34  73  T a b l e 10.  F a t t y a c i d c o m p o s i t i o n o f s t e e l h e a d s m o l t s r e a r e d i n net-pens. V a l u e s a r e means f o r f o u r samples w i t h each sample c o n s i s t i n g o f two f i s h .  " T r a c e " i n d i c a t e s £0.05%, £0.005 mg/g.  \  74 Fatty  Fatty acid composition (%)  Fatty acid (mg/g wet tissue)  acid  Neutral  Polar  Whole  Neutral  Polar  Whole  type  lipid  lipid  lipid  lipid  lipid  lipid  14:0  2.1  0.6  1.7  0.40  0.04  0.44  14:1  0.2  trace  0.1  0.04  trace  0.04  unknown  0.1  trace  trace  trace  trace  trace  15:0  0.4  0.2  0.3  0.07  0.01  0.08  15:1  trace  trace  trace  0.01  trace  0.01  16:0  13.2  18.7  14.7  2.58  1.28  3.86  16:lu7  3.8  1.4  3.2  0.74  0.10  0.84  17:0  0.6  0.6  0.6  0.11  0.04  0.15  17:1  0.4  0.1  0.3  0.08  0.01  0.09  18:0  4.2  5.2  4.5  0.81  0.36  1.17  18:la)9  27.0  10.2  22.8  5.27  0.70  5.97  18:2a>6  25.8  5.5  20.6  5.03  0.38  5.41  18:3u6  0.2  0.1  0.03  18:303  2.4  0.7  2.0  0.47  0.05  0.51  20:lu9  2.7  0.4  2.2  0.53  0.03  0.56  18:4u)3  0.4  0.1  0.3  0.07  trace  0.07  20:2b)6  1.4  0.6  1.2  0.28  0.04  0.32  20:3(D6  0.7  0.6  0.7  0.14  0.04  0.18  20:4u6  0.8  3.1  1.4  0.16  0.22  0.38  22:lu)9  1.3  1.0  0.25  20:4o)3  0.4  0.2  0.3  0.07  0.02  0.09  20:5u3  1.7  4.4  2.4  0.33  0.31  0.64  22:3o)6  trace  trace  trace  0.01  trace  0.01  22:4a)6  0.2  0.2  0.2  0.04  0.01  0.05  unknown  1.2  0.9  0.23  22:4o)3  1.9  0.5  unknown  0.1  trace  0.03  0.25  0.23 0.13 trace  22:5a)3  0.6  0.9  0.7  0.12  0.06  22:6(D3  7.8  43.8  17.2  1.52  3.01  0.13 trace 0.18 4.53  75  T a b l e 11.  F a t t y a c i d c o m p o s i t i o n of some a q u a t i c i n s e c t s and h a t c h e r y d i e t s . " T r a c e " i n d i c a t e s <0.05%.  76 Fatty a c i d composition  (%)  Aquatic insects  Hatchery  Fatty  diets  Oregon  acid  Ephemei-  type  optera  Plecoptera  Chirono-  Trich-  moist  Sil\  midae  optera  pellet  Cup  14:0  3.6  1.2  5.4  6.2  4.3  3.3  14:1  0.6  1.2  2.8  3.8  0.1  0.1  unknown  0.2  0.1  -  0.2  -  -  15:0  0.4  trace  0.6  0.1  0.2  0.4  15:1  0.1  -  trace  -  0.3  0.1  16:0  26.2  17.0  19.9  22.4  13.5  17.9  16:lu7  14.7  9.3  14.3  12.2  9.8  4.4  -  0.8  -  -  - .  trace  -  trace  -  -  -  17:1  1.0  1.0  0.8  1.1  0.9  0.7  18:0  2.2  3.8  3.7  2.2  2.0  4.7  18:la.9  20.4  32.4  23.3  22.3  16.8  17.0  unknown  0.2  0.7  0.3  18:2u6  3.82  17:0 unknown  18:3u6 18:3(1)3  11.9  2.6  -• 18.8  -  - •  1.2  11.5  5.1  4.3  17.6  ' 0.1  -  -  .  trace  2.9  2.0  11.9  20:1(1)9  -  -  1.4  -  12.5  2.3  18:4ID3  1.5  1.1  0.4  1.7  1.4  1.1  20:2u6  -  -  -  -  0.1  0.2  20:3u6  -  -  -  -  -  trace  20:4u>6  0.7  1.0  2.0  0.6  trace  1.1  22:lu.9  -  -  -  -  17.8  2.1  20:4u3  0.1  0.1  0.2  -  -  0.4  20:5a.3  11.7  8.7  9.7  7.6  7.1  6.4  22:4u6  -  -  -  -  0.7  0.4  unknown  0.6  1.0  1.4  2.6  -  _  22:4u3  -  -  -  -  1.5  1-3  22:5<i>3  -  trace  -  -  0.6  1.0  22:6u)3  0.2  -  0.6  -  5.4  13.3  77  T a b l e 12.  F a t t y a c i d c l a s s c o m p o s i t i o n (%) of some a q u a t i c i n s e c t s hatchery d i e t s .  and  insects  Plecoptera  Chironomidae  Hatchery diets  Ephemeroptera  Aquatic  Saturated  32.4  22.8  29.6  30.9  20.0  27.5  Monounsaturated  36.8  43.9  42.6  39.4  58.2  26.7  Polyunsaturated  29.9  32.3  26.5  26.9  21.1  45.7  w6  4.5  3.6  13.6  5.7  5.1  19.3  o)3  25.4  28.7  12.9  21.2  16.0  26.4  Fatty acid  class composition  o)6/w3  0.18  0.13  1.05  Oregon  Silver  Moist Pellet  0.27  0.32  Cup  0.73  F i g . 1.  Map  of the s t u d y a r e a s showing the Keogh, Qualicum  and C a p i l a n o r i v e r s .  81  F i g . 2.  Map o f the Qualicum r i v e r system.  83  F i g . 3.  Map o f the Keogh r i v e r system.  84  QUEEN CHARLOTTE STRAIT  SCALE  KEOGH RIVER  O'CONNOR LAKE STEELHEAD PENS  2 . 4  V  k  m  85  F i g . 4.  Map o f the C a p i l a n o r i v e r system.  86  87  F i g . 5.  F o r k l e n g t h s o f Qualicum coho salmon. confidence l i m i t s .  V a l u e s a r e means w i t h 95%  88  89  F i g . 6.  Wet w e i g h t s o f Qualicum coho salmon. confidence l i m i t s .  V a l u e s a r e means w i t h 95%  20  90  91  F i g . 7.  C o n d i t i o n f a c t o r s of Qualicum coho salmon. 95% c o n f i d e n c e  limits.  V a l u e s a r e means w i t h  92  8.0 NATURAL I  B  fl  o--o  PRODUCTION - CHANNEL REARING - CHANNEL  7.0 cm  O  »—  U  < z o  O u  6.0|  5.01  JULY  SEPT 1978  NOV  JAN  JL  MAR 1979  MAY  93  F i g . 8.  S e a s o n a l v a r i a t i o n s i n m o i s t u r e c o n t e n t o f Qualicum V a l u e s a r e means w i t h 95% c o n f i d e n c e  limits.  coho salmon.  1  MAY  I  I  JULY  SEPT 1978  I  NOV  I  JAN  I  MAR 1979  1 —  MAY  95  F i g . 9.  S e a s o n a l v a r i a t i o n s i n ash c o n t e n t o f Qualicum V a l u e s a r e means w i t h 95% c o n f i d e n c e l i m i t s .  coho salmon.  96  MAY  JULY  SEPT 1978  NOV  JAN  MAR  MAY 1979  97  F i g . 10.  S e a s o n a l v a r i a t i o n s i n p r o t e i n c o n t e n t o f Qualicum V a l u e s a r e means w i t h 95% c o n f i d e n c e l i m i t s .  coho salmon.  98  1  MAY  •  1  JULY 1978  SEPT  I  NOV  L.  JAN  I  I  MAR  MAY 1979  99  F i g . 11.  S e a s o n a l v a r i a t i o n s i n l i p i d c o n t e n t o f Q u a l i c u m coho salmon. V a l u e s a r e means w i t h 95% c o n f i d e n c e l i m i t s .  The sample t a k e n  on December 5, 1978 f o r t h e w i l d coho seems t o be w i t h the other r e s u l t s .  inconsistent  100  NATURAL •-—  PRODUCTION-CHANNEL  o-.-o REARING-CHANNEL  MAY  JULY  SEPT 1978  NOV  JAN  MAR 1979  MAY  101  F i g . 12.  S a t u r a t e d f a t t y a c i d s i n coho salmon from the Qualicum r i v e r . V e r t i c a l l i n e s r e p r e s e n t o n e - h a l f o f the 95% c o n f i d e n c e  limits.  Groups w i t h the same s u p e r s c r i p t form a homogeneous subset (AN0VA, S c h e f f e ' s t e s t , p<0.05).  28.01  I ^  a  I  [Til  PRODUCTION-CHANNEL REARING-CHANNEL  26.0H NATURAL  o u 12.0  24.0-  < ~ 3  JL 2  22.0H cn \ <  20.0 4  1  18.0 NEUTRAL  POLAR  WHOLE  NEUTRAL LIPID  M.O  OC  z> t—  • •  • •  •  •  •  •  POLAR  <  to  WHOLE  E  O  103  F i g . 13.  Monounsaturated f a t t y a c i d s i n coho salmon from the Qualicum r i v e r . V e r t i c a l l i n e s r e p r e s e n t o n e - h a l f o f the 95% c o n f i d e n c e l i m i t s . Groups w i t h the same s u p e r s c r i p t form a homogeneous subset (AN0VA, S c h e f f e ' s t e s t , p<0.05).  70.On  PI  PRODUCTION-CHANNEL  E3  REARING-CHANNEL LO  t o Q  y  58.0H  L  <  »— <  <  46.0H • • • • • •  34.0-^  < Z r> O z o  •  •  •  •  •  •  •  L  •a • • • • • •  X  1  22.0-  •  NEUTRAL  POLAR  NEUTRAL  WHOLE LIPID  •  • • a o o o • o  '  10.0  ^  L.18.0  <  Innk'.'l POLAR  3  - o  1  1  o • • •  OC t o  •  24.0  X  I  I t—  9  NATURAL  •  •  •  •  • o  • •  I  WHOLE  12.0  <  OC 3 t o  V6.0  Z  I D  o z o  cn E  105  F i g . 14.  P o l y u n s a t u r a t e d f a t t y a c i d s i n coho salmon from t h e Qualicum r i v e r . V e r t i c a l l i n e s r e p r e s e n t o n e - h a l f o f the 95% c o n f i d e n c e  limits.  Groups w i t h t h e same s u p e r s c r i p t form a homogeneous subset S c h e f f e ' s t e s t , p<_0.05).  (ANOVA,  66.CH  a,b JL a  58. OH  g  1  50.0-  D  •  •  •  •  •  1  f~l  REARING-CHANNEL  •  •  •  •  •  a a  a •  a.b  • • •  1  9. 34.04 26-0-  IM a w . .  I  18.0-  I • a • •  •  NEUTRAL  g  9  1  • •  42.0-  18.0  NATURAL  • • Q O •  PRODUCTION-CHANNEL  14.0  >_  ~ *  CO wn  •  •  •  • o a • a • o  • • • • • • •  •  •  1  1  I  TTTT  • • [ • a  •  •  •  •  •  •  •  •  •  • • •  •  •  •  POLAR  a • • • a  •  • • I o I la a I• la  • • • a  • •  a a  WHOLE  NEUTRAL LIPID  • • •  7tt  10.0  POLAR  a  • • • • • • • • • • • a • • • •  WHOLE  £  <  an U)  • o  • •  •  ab  •  • a •  • • a  r6.0  < to Z 3  o  E  o o  107  F i g . 15.  F a t t y a c i d s o f t h e CJ6 s e r i e s i n coho salmon from t h e Qualicum river. limits.  V e r t i c a l l i n e s represent  one-half  o f t h e 95% c o n f i d e n c e  Groups w i t h t h e same s u p e r s c r i p t form a homogeneous  subset (ANOVA, S c h e f f e ' s  t e s t , p<0.05).  I  I PRODUCTION - CHANNEL  H  REARING - CHANNEL  >N  NATURAL  H6.0  12.CH  CO  o  g < 8.0>-  a.b b  1 "  < •o  a  4.0-  r-4.0  1  JL  NEUTRAL  POLAR  S  •-  >»—  <  3  0  <  0) 3 —'  D  •  •  •  NEUTRAL  WHOLE LIPID  b b a , w • jr. rnnotv.1 POLAR  • • •  c  • i  t  •  WHOLE  12.0  e  o  3  o  00  109  F i g . 16.  F a t t y a c i d s of the o>3 s e r i e s i n coho salmon from the Qualicum r i v e r . V e r t i c a l l i n e s represent  one-half  of the 95% c o n f i d e n c e  limits.  Groups w i t h the same s u p e r s c r i p t form a homogeneous s u b s e t (ANOVA, S c h e f f e ' s  t e s t , p_<0.05).  6O.O1  PRODUCTION - CHANNEL  ^ L»fi-I  50.0H  [01  REARING-CHANNEL  CO  o ^  CO  NATURAL  40.0-1  M2.0  I  9 < >-  t— <  8.0  30.0H  3  a  a  CO  T  i_ a  20.0-  a  I -  10.0-  ^ ~  • a  • «  • •  NEUTRAL  |TT-I  •  •  • •  • •  a a •  I a a  POLAR  WHOLE  • • •  D  n  o  •  r  :| • •  a  • • • o a •  1  CO  L4.0  » • » •  • • , • •  !«  NEUTRAL LIPID  a  T,J  •  > •  0  POLAR  WHOLE  3  3  0)  cn cn E  Ill  F i g . 17.  R a t i o o f u>6/u>3 f a t t y a c i d s i n coho salmon from the Qualicum r i v e r , and s t e e l h e a d t r o u t from t h e Keogh r i v e r . o n e - h a l f o f t h e 95% c o n f i d e n c e l i m i t s . s u p e r s c r i p t form a homogeneous s u b s e t p<0.05).  Vertical lines  represent  Groups w i t h the same (ANOVA, S c h e f f e ' s  test,  2.4-1  C]  PRODUCTION-CHANNEL  2.0H  </>  o  1.6-  REARING-CHANNEL  •  PEN-REARED  NATURAL  ±3  NATURAL to  < < U-  1.2-  1  ro  3  0.8-  X  «o 3  •  1  0.44  NEUTRAL  i3 SM.  COHO  POLAR  b a • a • D  b 4-  •  WHOLE  SALMON LIPID  a  NEUTRAL  POLAR  WHOLE  STEELHEAD TROUT LIPID  113  F i g . 18.  S a t u r a t e d f a t t y a c i d s i n s t e e l h e a d t r o u t from t h e Keogh r i v e r . V e r t i c a l l i n e s r e p r e s e n t o n e - h a l f o f t h e 95% c o n f i d e n c e Groups w i t h the same s u p e r s c r i p t form a homogeneous (ANOVA, S c h e f f e ' s t e s t , p<0.05).  limits.  subset  CU  PEN-REARED  NATURAL  27.(H  H2.0  a  23.0-i  a a  19.0H  J L  >• «  j .  1  " 1  a  a  15.0 NEUTRAL  POLAR  WHOLE  NEUTRAL LIPID  POLAR  WHOLE  115  F i g . 19.  Monounsaturated f a t t y a c i d s i n s t e e l h e a d t r o u t from t h e Keogh river. limits. subset  V e r t i c a l l i n e s r e p r e s e n t o n e - h a l f o f t h e 95% c o n f i d e n c e Groups w i t h t h e same s u p e r s c r i p t form a homogeneous (ANOVA, S c h e f f e ' s t e s t , p<0.05).  20.0  r  • 42.CH  PEN-REARED H6.0  NATURAL  to Q U <  T T  34.CH  M2.0  a • • •; 2.  LU  26.0-  H8.0  18.0-  10.0-  3 —.  h4.0 > •  <  > •  <  A l a  NEUTRAL  I  n  I  n  POLAR  WHOLE  NEUTRAL LIPID  • •  POLAR  0 WHOLE  <  CO  cn  <  cn  z o z o  E  117  F i g . 20.  P o l y u n s a t u r a t e d f a t t y a c i d s i n s t e e l h e a d t r o u t from the Keogh river. limits. subset  V e r t i c a l l i n e s r e p r e s e n t o n e - h a l f o f t h e 95% c o n f i d e n c e Groups w i t h t h e same s u p e r s c r i p t form a homogeneous (ANOVA, S c h e f f e ' s t e s t ,  p<0.05).  • g  PEN-REARED  NATURAL  CO  <  g  64 .(H  a  K24.0  <  <  a  56.0H  1  LU  <  Z)  < z  u .  48.0• T  >  o  <  1-  M6.0  h8.0 a  POLAR  0  WHOLE  NEUTRAL LIPID  POLAR  <  to Z  40.0WHOLE  2  <  ,  NEUTRAL  Q  .2  Z> >O  I  CO  E  119  F i g . 21.  F a t t y a c i d s o f the o>6 s e r i e s i n s t e e l h e a d  t r o u t from the Keogh  river.  of t h e 95%  limits.  V e r t i c a l l i n e s represent  one-half  confidence  Groups w i t h t h e same s u p e r s c r i p t form a homogeneous  s u b s e t (ANOVA, S c h e f f e ' s  t e s t , p<0.05).  I  I  FSI  32.0-  PEN-REARED NATURAL  H8.0  r h  a  6.0  g 24.0H  a> o D-  <  < 16.0  4.0  <  UL.  o  3  CO  ^ »  b  b  2.0  l  •v •v •v  e e • •  •_2_  NEUTRAL  a>  <  a 8.0<  >  «/»  •!•• ••••  • o • a  POLAR  WHOLE  NEUTRAL LIPID  POLAR  WHOLE  3  cn E  121  F i g . 22.  F a t t y a c i d s o f t h e u3 s e r i e s i n s t e e l h e a d  t r o u t from the Keogh  river.  o f t h e 95%  limits.  V e r t i c a l l i n e s represent  one-half  confidence  Groups w i t h t h e same s u p e r s c r i p t form a homogeneous  s u b s e t (ANOVA, S c h e f f e ' s  t e s t , p<0.05).  co 3  m C —I  Cn  o 6  o b  z  ACIDS ( 1 )  FATTY  CO  b  1  _ i _  TO  > o  I—  > TO  ........  cr  I  X  O  ••••••••••••• •••••• ••••••• ••'•• •• •• ••••••••••• •••• •**••*•», • •••••••••• |  •  03 z >  z  —i  m C  —(  >  •«• •  ~o  o  I—  > TO O  H T T > • • • • •  HO"  TO >  Q  H Q  • • • • • • »»«  • • <  • •  a  t  •• • •• •  -r" 00  O  T"  b  3 FATTY ACIDS ( mg / g wet tissue )  CO  -H —r—  to  o  CT  z  I  TO  m >  TO  123  Appendix t a b l e 1.  P r o x i m a t e c o m p o s i t i o n (% d r y t i s s u e ) o f n a t u r a l l y - r e a r e d coho salmon from the Qualicum r i v e r . w i t h 95% c o n f i d e n c e l i m i t s .  V a l u e s a r e means  124  Proximate Sampling Date May 8  1978  No. Samples  Ash  10  8 .94  4-  composition  (% d r y  tissue)  Protein  Lipid  0 .91  7 4 . 34  + 4, . 3 0  1 4 . 34  + 1 .94  June  13  10  11 . 8 3  + 1 .47  7 6 . 36  + 4, .81  10. 60  + 2 .18  July  18  10  12 . 6 5  + 1 .14  7 8 . 56  + 2, . 2 7  7 . 45  + 1 .17  15  12 . 0 8  + 0 .56  7 7 . 85  + 1, . 9 3  7 . 43  + 0 .84  15  12 . 9 0  + 0 .59  7 4 . 93  + 1, . 2 9  8 . 41  + 0 .89  13 .21  + 0 .89  7 4 . 25  + 1. . 8 5  8 . 46  Aug  15  Sept  12  Oct  9  10  Nov  7  9  13 . 4 9  + 1 .30  7 4 . 92  + 2 , .21  8 . 34  + 1 .36  Dec 5  10  13 . 0 5  + 1 .06  7 7 . 08  + 5 . .16  1 4 . 31  + 2 .30  7  13 . 3 7  + 2 .71  71. 80  + 5,.99  8 . 53  + 2 .20 + 1 .49  0 .77  Jan  9  Feb  5  10  13 . 2 2  + 1 .12  7 2 . 72  + 1, .41  1 1 . 04  Mar 5  10  13 . 9 2  + 1 .22  7 5 . 15  + 1. .77  7 . 53  4  6  15 . 2 3  + 2 .67  7 5 . 37  + 2 . .16  9 , 67  + 1 .77  10  12 . 4 2  + 1 .24  7 7 . 73  + 4..40  1 4 . 25  + 2 .05  April May  31  1979  .  2  1 .28  125  Appendix t a b l e 2.  P r o x i m a t e c o m p o s i t i o n (% d r y t i s s u e ) o f p r o d u c t i o n c h a n n e l coho salmon from the Qualicum a r e means w i t h 95% c o n f i d e n c e l i m i t s .  river.  Values  126  Proximate Sampling Date April  20  No. Samples 1978  Aug 22 Jan  15  April May 14  1979 9  Ash  composition  (% d r y t i s s u e )  Protein  Lipid  10  7.41+0.58  73.11+5.86  17.13+1.27  15  9.61+0.32  63.80+1.69  21.21+1.20  10  10.29+0.85  68.19+3.91  16.62+3.15  10  11.02+0.61  65.38+3.30  18.78+2.03  10  10.72+0.97  65.90+1.67  18.59+1.41  127  Appendix t a b l e 3.  P r o x i m a t e c o m p o s i t i o n (% d r y t i s s u e ) o f r e a r i n g - c h a n n e l coho salmon from the Qualicum w i t h 95% c o n f i d e n c e l i m i t s .  river.  V a l u e s a r e means  128  Proximate composition Sampling Date ; April  20  Aug  22  Jan  15  April May  1978  1979 9  17  No. Samples  Ash  (% d r y  tissue)  Protein  10  7.06  + 0.49  7 1 . 32 + 1 . 1 9  15  10.33  + 0.43  6 3 . 93  10  11.31  + 1.29  6 8 . 81  10  12.76  10  11.99  Lipid 17.22  + 2.07  + 1 .75  20.35  + 1.54  + 1 .70  14.51  + 1.52  + 0.99  7 2 . 00 + 1 . 8 0  13.45  + 0.97  + 0.52  6 9 . 25 + 1 . 2 2  15.28  + 0.81  129  Appendix t a b l e 4.  Whole body p r o x i m a t e c o m p o s i t i o n (% l i p i d - f r e e d r y t i s s u e ) of coho salmon and s t e e l h e a d t r o u t . 95% c o n f i d e n c e l i m i t s .  V a l u e s a r e means w i t h  Groups w i t h the same s u p e r s c r i p t  form a homogeneous s u b s e t (ANOVA, S c h e f f e ' s t e s t , p<0.05).  Groups from d i f f e r e n t l i f e h i s t o r y s t a g e s and  r i v e r systems a r e a n a l y s e d s e p a r a t e l y .  Proximate (% R e a r i ng method  Q u a l i cum coho  lipid-free Ash  dry  tissue) Protei n  Natural  16.83 ± 2.53  P r o d u c t i on channel  13.57 ± 0.87  Reari ngchannel  14.74 ± 1.14  presmolt  composition  a  83.44 ± 2.37  a  b  80.49 ± 2.77  a  83.22 ± 1.90  a  a  CO  O  Q u a l i cum coho  Natural  14.43 ± 1.22  a  90.61 ± 3.88  a  P r o d u c t i on channel  13.14 ± 1.09  a  80.94 + 1.14  b  Rea r i n g channel  14.16 ± 0.67  81.98 ± 1.68  b  Natural  14.07 ± 1.21  a  88.98 ± 2.36  a  Hatchery  13.45 ± 1.57  a  85.76 ± 3.53  a  Natural  12.70 ± 1.55'  84.04 ± 2.94'  Pen  13.58 + 1.90'  83.36 ± 2.69'  smol t  Capilano coho  a  smol t  Keogh s teelhead smol t  

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