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Racial analysis of Skeena River steelhead trout (Salmo gairdneri) by scale pattern features 1985

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RACIAL ANALYSIS OF SKEENA RIVER STEELHEAD TROUT (SALMO GAIRDNERI) BY SCALE PATTERN FEATURES by STEVEN FRANK COX-ROGERS B . S c . , U n i v e r s i t y Of B r i t i s h Columbia,1981 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE i n THE FACULTY OF GRADUATE STUDIES (Department of Zoology) We accept t h i s t h e s i s as conforming to the r e q u i r e d standard THE UNIVERSITY OF BRITISH COLUMBIA September 1985 © Steven Frank Cox-Rogers, 1985 In presenting this thesis in partial fulfilment of the requirements for an advanced degree at the University of British Columbia, I agree that the Library shall make it freely available for reference and study. I further agree that permission for extensive copying of this thesis for scholarly purposes may be granted by the head of my department or by his or her representatives. It is understood that copying or publication of this thesis for financial gain shall not be allowed without my written permission. Department of The University of British Columbia 1956 Main Mall Vancouver, Canada V6T 1Y3 Date OCT" / o/fitf DE-6(3/81) i i ABSTRACT The f e a s i b i l i t y of using freshwater and f i r s t marine year s c a l e p a t t e r n s to i d e n t i f y component stock s of s t e e l h e a d t r o u t (Salmo g a i r d n e r i ) i n the Skeena R i v e r was i n v e s t i g a t e d . Scale samples and sex and s i z e data were a t t a i n e d from a d u l t s t e e l h e a d o r i g i n a t i n g from f i v e Skeena River t r i b u t a r i e s (Zymoetz, K i s p i o x , M o r i c e - B u l k l e y , Babine, Sustut) over a s e r i e s of d i f f e r e n t y e a r s . Adult s c a l e samples were a l s o c o l l e c t e d from the 1984 i n c i d e n t a l s t e e l h e a d c a t c h i n the Area 4 commercial salmon f i s h e r y f o r p o t e n t i a l stock c l a s s i f i c a t i o n purposes. S i g n i f i c a n t d i f f e r e n c e s in s c a l e p a t t e r n growth, age composition, and s i z e s at age were found between the f i v e Skeena River s t e e l h e a d s t o c k s . L i n e a r d i s c r i m i n a n t f u n c t i o n a n a l y s i s i n d i c a t e d t h a t the f i v e stocks c o u l d be c l a s s i f i e d to c o r r e c t r i v e r of o r i g i n with between 45% and 62% average c l a s s i f i c a t i o n accuracy (range Zymoetz 29%-60%, K i s p i o x 35%-60%, M o r i c e - B u l k l e y 44%-76%, Babine 54%-64%, Sustut 56%-72%) depending upon the c l a s s i f i c a t i o n model used. J u v e n i l e morphometric a n a l y s i s f o r three of the stocks ( K i s p i o x , M o r i c e - B u l k l e y , Zymoetz) i n d i c a t e d the presence of s i g n i f i c a n t between stock d i f f e r e n c e s i n s t a n d a r d i z e d body form. These r e s u l t s support the notion that Skeena R i v e r s t e e l h e a d e x i s t as q u a n t i f i a b l y d i s c r e t e s t o c k s . C l a s s i f y i n g the 1984 mixed stock commercial f i s h e r y catches to probable stock of o r i g i n i n d i c a t e d t h a t d i s t i n c t peaks of stock abundance and run-timing occur through the f i s h e r y . In g e n e r a l , M o r i c e - B u l k l e y and Sustut R i v e r s t e e l h e a d were p r e d i c t e d to be most abundant with run-timings d u r i n g the e a r l i e r p o r t i o n s of the f i s h e r y . K i s p i o x , Babine, and Zymoetz River s t e e l h e a d were p r e d i c t e d to be l e s s abundant with l a t e r run-timings through the f i s h e r y . P o t e n t i a l commercial f i s h e r y impacts to s t e e l h e a d are b r i e f l y d i s c u s s e d . These o b s e r v a t i o n s suggest that the technique of s c a l e p a t t e r n s i s a f e a s i b l e method f o r stock s e p a r a t i o n i n Skeena River s t e e l h e a d . F u r t h e r study i s r e q u i r e d to c l a r i f y y e a r l y v a r i a n c e i n the technique and to b e t t e r e s t a b l i s h stock s p e c i f i c d i f f e r e n c e s . i v TABLE OF CONTENTS ABSTRACT i i LIST OF TABLES v i LIST OF FIGURES . . v i i i ACKNOWLEDGEMENTS x i I n t r o d u c t i o n 1 D e s c r i p t i o n of the Skeena R i v e r Drainage 5 L i f e H i s t o r y of Skeena River Steelhead 8 The Skeena R i v e r Commercial Salmon F i s h e r y 10 M a t e r i a l s and Methods 17 Sca l e Data C o l l e c t i o n and P r e p a r a t i o n 17 Determination of Sample S i z e s 23 J u v e n i l e A n a l y s i s 24 A n a l y t i c a l Techniques" f o r S c a l e P a t t e r n A n a l y s i s .... 25 R e s u l t s 30 D i s c r i m i n a t i o n of Skeena R i v e r Steelhead 30 V e r i f i c a t i o n of s c a l e aging 30 D e s c r i p t i v e s t a t i s t i c s 30 Age composition 30 S i z e s at age 35 Sca l e P a t t e r n F e a t u r e s of Skeena River s t e e l h e a d .... 40 Sc a l e f e a t u r e s of smolt age 3 a d u l t s t e e l h e a d .... 41 Sca l e f e a t u r e s of smolt age 4 a d u l t s t e e l h e a d .... 48 Sca l e f e a t u r e s of age 3.2+ and 4.2+ s t e e l h e a d .... 52 Sc a l e p a t t e r n v a r i a t i o n between years 55 Plus growth 57 Stock D i s c r i m i n a t i o n 57 Separate freshwater age d i s c r i m i n a n t models 58 Pooled freshwater age d i s c r i m i n a n t models 72 D i s c r i m i n a t i o n by sex 75 Commercial F i s h e r y Stock Composition 76 J u v e n i l e A n a l y s i s 84 D i s c u s s i o n 97 B i o l o g i c a l C o n s i d e r a t i o n s 97 T h e o r e t i c a l C o n s i d e r a t i o n s 105 Commercial F i s h e r y C o n s i d e r a t i o n s 108 A p p l i c a t i o n s to Steelhead Management 114 LITERATURE CITED 1 1 8 LIST OF TABLES Table 1.Riverine f e a t u r e s of the f i v e Skeena R i v e r t r i b u t a r i e s used i n the study 9 Table 2. V a r i a b l e s measured from the a d u l t s t e e l h e a d s c a l e s f o r each stock . 22 Table 3. Age Composition f e a t u r e s of Skeena River s t e e l h e a d by sex, smolt age, and ocean age 34 Table 4. Mean lengths and weights of s t e e l h e a d at v a r i o u s ocean age f o r the f i v e stocks used i n the study 40 Table 5. One way ANOVA r e s u l t s f o r comparison of d i f f e r e n c e s i n mean s c a l e zone widths at age f o r st e e l h e a d from the K i s p i o x , Zymoetz, and M o r i c e - B u l k l e y R i v e r s 44 Table 6. One way ANOVA r e s u l t s f o r comparison of d i f f e r e n c e s i n mean s c a l e zone f e a t u r e s f o r smolt age 3 s t e e l h e a d by pooled ocean age 47 Table 7. One way ANOVA r e s u l t s f o r comparison of d i f f e r e n c e s i n mean s c a l e zone f e a t u r e s f o r smolt age 4 st e e l h e a d by pooled ocean age 51 Table 8. One way ANOVA r e s u l t s f o r comparison of d i f f e r e n c e s i n mean s c a l e zone f e a t u r e s f o r age 3.2+ and 4.2+ s t e e l h e a d 55 Table 9. One way ANOVA r e s u l t s f o r comparison between years i n mean s c a l e zone f e a t u r e s f o r Sustut and Zymoetz R i v e r s t e e l h e a d 56 Tables 10-16. C l a s s i f i c a t i o n m a t r ices f o r the l i n e a r d i s c r i m i n a n t models used to c l a s s i f y Skeena R i v e r s t e e l h e a d to stock of o r i g i n 62 Table 17. 1984 commercial f i s h e r y s t e e l h e a d c a t c h e s i n Area 4 79 Table 18. Ocean age composition by sex f o r s t e e l h e a d sampled from Area 4 i n 1984 79 Table 19. Mean lengths and weights of s t e e l h e a d sampled from Area 4 i n 1984 80 Table 20. C l a s s i f i c a t i o n r e s u l t s to stock of o r i g i n by week for s t e e l h e a d sampled from Area 4 i n 1984 81 Table 21. Means and the r e s u l t s of one way ANOVAS f o r comparison of d i f f e r e n c e s i n mo r p h o l o g i c a l f e a t u r e s i n j u v e n i l e s t e e l h e a d 95 v i i i LIST OF FIGURES F i g u r e 1. The Skeena R i v e r Drainage 6 F i g u r e 2. 1963 to 1984 mean annual s t e e l h e a d harvest by month i n Area 4 13 Fi g u r e 3. 1963 to 1984 mean s t e e l h e a d escapement by month through Area 4 13 F i g u r e 4. 1963 to 1984 mean annual s t e e l h e a d harvest+escapement i n Area 4 15 F i g u r e 5. Adu l t s t e e l h e a d s c a l e from the Sustut R i v e r ..... 19 F i g u r e 6. D i s c r i m i n a n t space 28 F i g u r e 7. Age composition s t r u c t u r e f o r the f i v e s t e e l h e a d stocks used i n the study 31 F i g u r e 8. Mean lengths of age 3.2+ and 4.2+ s t e e l h e a d from the f i v e stocks used i n the study 36 F i g u r e 9. Mean weights of age 3.2+ and 4.2+ s t e e l h e a d f o r the f i v e stocks used i n the study 36 F i g u r e 10. Mean lengths by sex f o r age 3.2+ s t e e l h e a d from the f i v e stocks used i n the study 38 Fi g u r e 11. Mean s c a l e zone widths f o r s t e e l h e a d of smolt ages 3 and 4 42 F i g u r e 12. Ye a r l y freshwater s c a l e zone widths i n a d u l t s t e e l h e a d of smolt age 3 by pooled ocean age 45 F i g u r e 13. Y e a r l y freshwater s c a l e zone c i r c u l i counts i n s t e e l e a d of smolt age 3 by pooled ocean age 45 F i g u r e 14. Ye a r l y freshwater s c a l e zone widths i n a d u l t s t e e l h e a d of smolt age 4 49 F i g u r e 15. Y e a r l y freshwater s c a l e zone c i r c u l i counts i n a d u l t s t e e l h e a d of smolt age 4 49 F i g u r e 16. Y e a r l y freshwater s c a l e zone widths in s t e e l h e a d of age 3.2 + 53 F i g u r e 17. Y e a r l y freshwater s c a l e zone widths in s t e e l h e a d of age 4.2+ 53 F i g u r e 18. D i s c r i m i n a n t f u n c t i o n a n a l y s i s d e s c r i b i n g s c a l e p a t t e r n v a r i a t i o n i n a d u l t s t e e l h e a d of smolt age 3 .... 59 F i g u r e 19. D i s c r i m i n a n t f u n c t i o n a n a l y s i s d e s c r i b i n g s c a l e p a t t e r n v a r i a t i o n i n a d u l t s t e e l h e a d of smolt age 4 .... 64 F i g u r e 20. D i s c r i m i n a n t f u n c t i o n a n a l y s i s d e s c r i b i n g s c a l e p a t t e r n v a r i a t i o n i n steelhead of age 3.2+ 67 F i g u r e 21. D i s c r i m i n a n t f u n c t i o n a n a l y s i s d e s c r i b i n g s c a l e p a t t e r n v a r i a t i o n i n s t e e l h e a d of age 4.2+ 70 F i g u r e 22. D i s c r i m i n a n t f u n c t i o n a n a l y s i s d e s c r i b i n g s c a l e p a t t e r n v a r i a t i o n i n a d u l t s t e e l h e a d of pooled smolt age 73 F i g u r e 23. Age composition s t r u c t u r e by week f o r s t e e l h e a d sampled i n the 1984 commercial f i s h e r y 77 F i g u r e 24. P r e d i c t e d run-timing 85 F i g u r e 25. P r e d i c t e d run-timing 85 F i g u r e 26. P r e d i c t e d run-timing 87 F i g u r e 27. P r e d i c t e d run-timing . .. 87 F i g u r e 28. P r e d i c t e d run-timing 89 F i g u r e 29. P r e d i c t e d run-timing 89 F i g u r e 30. P r e d i c t e d run-timing 91 X F i g u r e 31. P r e d i c t e d run-timing • 91 F i g u r e 32. D i s c r i m i n a n t f u n c t i o n a n a l y s i s d e s c r i b i n g m o rphological v a r i a t i o n among j u v e n i l e s t e e l h e a d from the Kispiox,Zymoetz,and M o r i c e - B u l k l e y R i v e r s 94 x i ACKNOWLEDGEMENTS I would l i k e to thank my s u p e r v i s o r Dr N.J. Wilimovsky and committee members Drs. A r t Tautz, J.D. M c P h a i l , and C a r l Walters f o r t h e i r a d v i c e and a s s i s t a n c e i n the development of t h i s t h e s i s . I would a l s o l i k e to thank Mike Lough, E r i c Parkinson, Bruce Ward, and Angelo Fachin of the P r o v i n c i a l F i s h e r i e s Branch and Les Janz of the F e d e r a l Department of F i s h e r i e s and Oceans f o r t h e i r h e l p f u l comments through numerous d i s c u s s i o n s . The B.C F i s h e r i e s Branch and the Department of F i s h e r i e s and Oceans pr o v i d e d f i n a n c i a l support f o r t h i s study. A note of thanks i s extended to the s t a f f of B.C. Packers P r i n c e Rupert D i v i s i o n f o r the use of t h e i r f a c i l i t y d u r i n g t h i s p r o j e c t . F i n a l l y , I would l i k e to express s i n c e r e g r a t i t u d e to my wife Marie who was always w i l l i n g to provide f i e l d a s s i s t a n c e and support when needed most. 1 INTRODUCTION F i s h e r i e s b i o l o g i s t s have long been i n t e r e s t e d i n determining subpopulation s t r u c t u r e i n mixed p o p u l a t i o n f i s h e r i e s ( C l u t t e r and Whit e s e l 1956, Worlund and F r e d i n 1962, Anas and Murai 1969, B i l t o n 1971, Cook and Lord 1978, P e l l a and Robertson 1979, Lear and Sandeman 1980, Maclean and Evans 1981, McDonald 1981, Conrad 1984). Whenever d i f f e r e n t spawning p o p u l a t i o n s of s i n g l e or s e v e r a l s p e c i e s i n t e r m i x , the h a r v e s t i n g of one may d i f f e r e n t i a l l y a f f e c t the other (McDonald, 1981). Not s u r p r i s i n g l y , t h i s has l e d to e x t e n s i v e a p p l i c a t i o n s of the "stock concept" (Simon and L a r k i n 1972, R i c k e r 1972, U t t e r 1981) i n mixed f i s h e r y management. The v a r i o u s spawning p o p u l a t i o n s of a given s p e c i e s are taken to represent l o c a l s t o c k s p o s s e s s i n g g e n e t i c d i f f e r e n c e s that are a d a p t i v e (Maclean and Evans, 1981) and which should be maintained ( L a r k i n , 1972). Because l e s s p r o d u c t i v e stocks are p a r t i c u l a r l y s u s c e p t i b l e to o v e r f i s h i n g i n a mixed f i s h e r y (McDonald, 1981), e f f e c t i v e management r e q u i r e s knowledge of which stocks are c o n t r i b u t i n g and how t h e i r d i s t r i b u t i o n s change over time. Mixed stock f i s h e r i e s a n a l y s e s i n North America have p r i m a r i l y c o n c e n t r a t e d on the salmonids, although not e x c l u s i v e l y ( H i l l 1959, Parsons 1971, Mis r a and Ni 1983). Because of t h e i r commercial importance, a l l of the P a c i f i c salmon (genus Oncorhynchus) as w e l l as the A t l a n t i c salmon (Salmo s a l a r ) have r e c e i v e d c o n s i d e r a b l e a t t e n t i o n . Less s t u d i e d have been non-target s p e c i e s harvested i n c i d e n t a l l y i n mixed stock f i s h e r i e s . The i n c i d e n t a l i n t e r c e p t i o n of s t e e l h e a d 2 t r o u t (Sa-lmo gairdner i ) i n net f i s h e r i e s f o r salmon along the P a c i f i c coast of North America i s one such example. Steelhead occur along the P a c i f i c coast from northern C a l i f o r n i a i n t o Alaska ( W i t h l e r , 1966). In B r i t i s h Columbia, s t e e l h e a d are harvested throughout t h e i r range (Oguss and Andrews 1977, Oguss and Evans 1978, Parkinson 1984a) with major i n c i d e n t a l f i s h e r i e s o c c u r r i n g in areas adjacent to the F r a s e r River and Skeena River e s t u a r i e s . With regard to the l a t t e r , the Skeena River hosts v a r i o u s " s t o c k s " of summer run s t e e l h e a d which are i n c i d e n t a l l y h a r vested d u r i n g the commercial sockeye (Oncorhynchus nerka) and pink salmon (Oncorhynchus qorbuscha) each year (June-September). An estimated 30%-60% of the t o t a l Skeena R i v e r s t e e l h e a d r e t u r n i n any given year i s h a r v e s t e d as i n c i d e n t a l c a t c h (unpublished data, BCFB 1984). L i t t l e i s known of s t e e l h e a d stock dynamics through the f i s h e r y nor of how commercial f i s h i n g may be a f f e c t i n g the b i o l o g i c a l i n t e g r i t y of each s t o c k . P r e l i m i n a r y i n v e s t i g a t i o n s by the B.C F i s h e r i e s Branch (unpublished data, 1982, 1984) suggest that the major Skeena R i v e r s t e e l h e a d stocks show d i s t i n c t "peaks of temporal abundance through the ' commercial f i s h e r y . The i d e n t i f i c a t i o n of each stock has been, however, q u i t e d i f f i c u l t . Of concern i s how each stock c o n t r i b u t e s p r o p o r t i o n a l l y to the weekly i n c i d e n t a l c a t c h . T h i s , i n t u r n , determines the o v e r a l l p a t t e r n of stock s p e c i f i c run-timing. Without such knowledge the management of Skeena River s t e e l h e a d has been l i m i t e d , e s p e c i a l l y f o r those stocks b e l i e v e d to c o i n c i d e with peak sockeye and pink salmon 3 run - t i m i n g . T h i s suggests the need f o r ways of i d e n t i f y i n g the stock o r i g i n s of Skeena R i v e r s t e e l h e a d i n the commercial salmon f i s h e r y . S e v e r a l techniques are a v a i l a b l e f o r i d e n t i f y i n g the r a c i a l o r i g i n s of salmonids i n n a t a l environments and i n mixed stock commercial f i s h e r i e s . Mark and recapture methods have been widely a p p l i e d i n v a r i o u s s t u d i e s (Hartt 1962); however, i n the case of w i l d s t e e l h e a d , they present s u b s t a n t i a l l o g i s t i c problems f o r both j u v e n i l e tagging and l a t e r a d u l t r e c a p t u r e . An a l t e r n a t i v e technique i s to use n a t u r a l l y o c c u r r i n g v a r i a t i o n i n one or more b i o l o g i c a l systems that are hypothesized or known to d i f f e r between p o p u l a t i o n s (Worlund and F r e d i n , 1962). E l e c t r o p h o r e t i c v a r i a t i o n ( s t e e l h e a d : U t t e r and A l l e n d o r f 1977, C h i l c o t e et a l . 1980, Parkinson 1984a, 1984b; A t l a n t i c salmon: Nyman and Pippy 1972, Thorpe and M i t c h e l l 1981; sockeye salmon: Grant et a l . 1980; chum salmon: F o u r n i e r et a l . 1984,), body morphology and m e r i s t i c s ( s t e e l h e a d : Smith 1969, Winter et a l . 1980; sockeye salmon: Fukuhara 1962, Dark and Landrum 1964 chinook salmon: McGregor 1924; pink salmon: Amos et a l . 1963; chum salmon: F o u r n i e r et a l . 1984; A t l a n t i c salmon: R i d d e l l and Leggett 1981; coho salmon: T a y l o r 1984), elemental composition (sockeye salmon: C a l i p r i c e 1971, M u l l i g a n et a l . 1983), age s t r u c t u r e (Ricker 1972) and p a r a s i t i c i n f e s t a t i o n s (sockeye salmon: M a r g o l i s 1958) have a l l been used with v a r y i n g degrees of success t o c h a r a c t e r i z e d i f f e r e n t spawning p o p u l a t i o n s . Perhaps the most widely a p p l i e d technique has been the use of c a l c a r e o u s s t r u c t u r e s such as o t o l i t h s ( s t e e l h e a d : 4 Mckern et a l . 1974), f i n rays (see Ihssen et a l . 1981) and e s p e c i a l l y s c a l e s ( A t l a n t i c salmon: Lear and Mis r a 1978, Lear and Sandeman 1980, Reddin and Mis r a 1985; P a c i f i c salmon: C l u t t e r and Whitesel 1956, Henry 1961 , Rowland 1969, Mosher 1963, Anas and Murai 1969, Tanaka et a l . 1969, B i l t o n 1971, B i l t o n and Messinger 1975, Cook and Lord 1978, Krasnowski e t a l . 1978, McBride and M a r s h a l l 1983, McGregor et a l . 1983, Conrad 1984). Sc a l e a n a l y s i s has c e r t a i n advantages over other stock i d e n t i f i c a t i o n techniques. S c a l e s are g e n e r a l l y e a s i e r to c o l l e c t and prepare, do not r e q u i r e k i l l i n g of the specimen, and are a p p l i c a b l e to l a r g e s c a l e stock i d e n t i f i c a t i o n s t u d i e s (Ihssen et a l . 1981). Steelhead s c a l e s have been read by many authors and have proven r e l i a b l e i n those p o p u l a t i o n s s t u d i e d (Neave 1944, Shapovalov and T a f t 1954, Maher 1954, Maher and L a r k i n 1955, Chapman 1958, B a l i 1958, W i t h l e r 1966, Narver 1969, Narver and W i t h l e r 1974, Whately 1977, Whately et a l . 1978, H o r n c a s t l e 1981, among o t h e r s ) . Few however, ( B a l i 1958, Keating 1959) have used s c a l e p a t t e r n s to c h a r a c t e r i z e p a r t i c u l a r s t e e l h e a d s t o c k s . Scale p a t t e r n a n a l y s e s r e l y on stock s p e c i f i c v a r i a t i o n s i n the widths and p a t t e r n s of s c a l e c i r c u l i and y e a r l y s c a l e growth zones. Environmental d i f f e r e n c e s between freshwater r e a r i n g environments are hypo t h e s i z e d to r e s u l t i n d i f f e r e n t i a l s c a l e growth d u r i n g the freshwater p e r i o d . The degree of s c a l e p a t t e r n d i f f e r e n c e between stoc k s determines the accuracy of s t a t i s t i c a l models used to separate them, o f t e n by d i s c r i m i n a n t a n a l y s i s . Both 5 parametric (Anas and Murai 1969, Major et a l . 1975, B i l t o n and Messinger 1975, Conrad 1984) and nonparametric (Cook and Lord 1978, Cook 1982) d i s c r i m i n a n t analyses have been a p p l i e d to a wide range of mixed salmonid f i s h e r y problems. The p o t e n t i a l of d i s c r i m i n a n t a n a l y s i s by s c a l e p a t t e r n s i s p a r t i c u l a r l y s u i t e d to Skeena R i v e r s t e e l h e a d as they rear i n n a t a l environments for long p e r i o d s of time and are s u b j e c t to longterm watershed s p e c i f i c growth regimes. T h i s t h e s i s examines the use of s c a l e p a t t e r n a n a l y s i s as a p r a c t i c a l method f o r d i f f e r e n t i a t i n g between s t e e l h e a d t r o u t stocks from the Skeena R i v e r . The goals of the study were two- f o l d . F i r s t l y , s c a l e p a t t e r n a n a l y s i s was used to t e s t the h y p o t h e s i s that s t e e l h e a d from the Skeena R i v e r e x i s t as r a c i a l l y separable s t o c k s . Secondly, s c a l e p a t t e r n a n a l y s i s was used to assess the p o t e n t i a l f o r i d e n t i f y i n g the weekly s t e e l h e a d c o n t r i b u t i o n s by stock to the commercial salmon f i s h e r y . D e s c r i p t i o n of the Skeena River Drainage The Skeena R i v e r d r a i n s an area of approximately 30,500 square k i l o m e t e r s l y i n g i n the c e n t r a l western p o r t i o n of B r i t i s h Columbia ( f i g u r e 1). C l i m a t i c p a t t e r n s vary i n an e a s t - west d i r e c t i o n with l i g h t p r e c i p i t a t i o n and extremes of temperature near the i n t e r i o r p l a t e a u and heavy p r e c i p i t a t i o n and moderate temperatures nearer the coast ( L a r k i n and McDonald, 1968). Seven Skeena R i v e r t r i b u t a r i e s , as w e l l as t h e i r sub- t r i b u t a r i e s , can be c o n s i d e r e d as h o s t i n g the major s t e e l h e a d 6 F i g u r e 1. The Skeena R i v e r Drainage. Shown are the major s t e e l h e a d t r i b u t a r i e s : the L a k e l s e , Kitsumkalum, Zymoetz, M o r i c e - B u l k l e y , K i s p i o x , Babine, and Sustut R i v e r s ( a f t e r Whately, 1977). 7 8 s t o c k s ; i n ascending order upstream from the mouth these are the La k e l s e , Kitsumkalum, Zymoetz (Copper), Morice-Bulkley-Suskwa, K i s p i o x , Babine, and Sustut r i v e r s r e s p e c t i v e l y . In a d d i t i o n , v a r i o u s other t r i b u t a r i e s ( E c s t a l l , Khyex, Eschamsiks, G i t n a d o i x , Khtada, Exstew, Kitwanga, K i t s e g u e c l a , S i c i n t i n e , Squingula e t c ) , sm a l l e r creeks, and the mainstem Skeena i t s e l f are known to support s t e e l h e a d p r o d u c t i o n . Two of the l a r g e r t r i b u t a r i e s , the Babine and M o r i c e - B u l k l e y R i v e r s , headwater i n la r g e lake systems. Table 1 summarizes the major r i v e r i n e f e a t u r e s f o r the f i v e Skeena t r i b u t a r i e s c o n s i d e r e d i n t h i s study (Zymoetz, M o r i c e - B u l k l e y , K i s p i o x , Babine, and Sustut R i v e r s ) . L i f e Hi s t o r y of Skeena R i v e r Steelhead Skeena River s t e e l h e a d taken i n c i d e n t a l l y i n the commercial f i s h e r y are p r i m a r i l y of summer and f a l l run o r i g i n which r e t u r n to the Skeena R i v e r as a d u l t s from June through September i n t h e i r f o u r t h , f i f t h , s i x t h , seventh, or e i g h t h p l u s years of l i f e . A f t e r o v e r w i n t e r i n g i n n a t a l streams the a d u l t s g e n e r a l l y spawn from mid A p r i l through June. Fry emergence occurs from mid to l a t e summer with the parr remaining i n freshwater f o r one to f i v e y e ars (winters) before smolting and m i g r a t i n g to the ocean. Not a l l a d u l t s d i e f o l l o w i n g spawning and many are taken as k e l t s i n the commercial f i s h e r y d u r i n g t h e i r seaward m i g r a t i o n . Winter and s p r i n g run s t e e l h e a d (November-April) are found i n the lower Skeena R i v e r t r i b u t a r i e s below Hazelton and Table 1.Riverine f e a t u r e s of the f i v e Skeena River t r i b u t a r i e s used i n the study. Feature Zymoetz Long. 128 27 W Lat. 54 32 N Drainage (sq km) 3080 Upstream (km) 115 Dis t a n c e app. Mean Flow (m3/s) Peak Flow Minimum Flow Length (km) 1 38 June Jan. 80 Summer T u r b i d i t y (JTU) Summer Water (C) Temperature Water Hardness (mg/1 CaCo3) Mean Annual (cm) Prec i p i t a t ion Mean January (C) a i r temp. Mean J u l y (c) a i r temp. F r o s t f r e e (days) p e r i o d 6-15 11-16 22-64 Mor i c e / B u l k l e y 126 43 W 1 54 24 N 12300(M+B) 1911(M) 200(B) 315(M) 164(M+B) 76(M) June Jan. 120(B) 75(M) 1 5-24 6-1 1 Ki spiox 27 40 W 1 55 1 5 N 2086 Babine 26 42 W 55 25 N 6790 1 5-25 10-16 24-33 9- 1 4 Sustut 127 20 W 56 00 N .3000 220 270 350 46 51 - June June June Feb. Mar . Mar. 1 37 85 65 24-52 6-10 1 00 to 40 to 40 to 40 to 50 to 350 250 1 00 75 75 _ 1 1 -15 -16 -18 -22 1 5 1 6 1 6 <1 4 < 1 4 60 to <60 to 60 to <70 <50 1 40 1 00 1 00 10 are not subject to any a p p r e c i a b l e i n c i d e n t a l (commercial) f i s h e r y . The M o r i c e - B u l k l e y r i v e r system and i t s t r i b u t a r i e s i s b e l i e v e d to support the m a j o r i t y of Skeena r i v e r s t e e l h e a d p r o d u c t i o n followed by the Babine, Zymoetz, Sustut, and K i s p i o x r i v e r systems r e s p e c t i v e l y (BCFW Branch, unpublished data, 1984) The L a k e l s e and Kitsumkalum r i v e r s are p r i m a r i l y winter run streams although t h e i r c o n t r i b u t i o n to summer run production i s r e c o g n i z e d . Mainstem Skeena River s t e e l h e a d production i s not known; however, i t may have an important r o l e i n r e a r i n g the l a r g e r p a r r o r i g i n a t i n g from s e v e r a l of the l e s s p r o d u c t i v e t r i b u t a r i e s (Tredger, 1984). Skeena R i v e r s t e e l h e a d have been p r e v i o u s l y examined f o r l i f e h i s t o r y f e a t u r e s i n the Morice- B u l k l e y River (Whately et a l . 1978), the K i s p i o x R i v e r (Whately, 1977), and the Babine R i v e r (Narver, 1969). Both T a y l o r (1968) and Pinsent and Chudyk (1973) d e s c r i b e d the Skeena Ri v e r system with regards to s t e e l h e a d . The Skeena River Commercial Salmon F i s h e r y The commercial salmon f i s h e r y on the Skeena River has had a d i v e r s e h i s t o r y (see M i l n e , 1955) c h a r a c t e r i z e d by f l u c t u a t i n g c atches of the two p r i n c i p l e t a r g e t s p e c i e s , sockeye and pink salmon ( L a r k i n and McDonald 1968, Todd and L a r k i n 1971, McDonald 1981). The m a j o r i t y of f i s h i n g e f f o r t occurs by g i l l n e t i n F i s h e r i e s s t a t i s t i c a l Area 4 adjacent ( w i t h i n 25-30 km) to the Skeena R i v e r e s t u a r y . An i n c r e a s i n g p r o p o r t i o n of s e i n e r s p a r t i c i p a t e in the f i s h e r y although they are p r i m a r i l y 1 1 r e s t r i c t e d to the outer r e g i o n s of Area 4. Other salmonid s p e c i e s taken i n the f i s h e r y i n c l u d e chinook (0 tshawytscha), chum (0 k e t a ) , and coho (0 k i s u t c h ) salmon as w e l l as small numbers of searun D o l l y Varden char ( S a l v e l i n u s malma) and c u t t h r o a t t r o u t (Salmo c l a r k i ) . Oguss and Andrews (1977) and Oguss and Evans (1978) reviewed the i n c i d e n t a l catches of s t e e l h e a d i n the Skeena R i v e r commercial f i s h e r y . Both sockeye and pink salmon are b e l i e v e d to pool i n area 4 f o r c o n s i d e r a b l e l e n g t h s of time before m i g r a t i n g upstream i n t o the Skeena River (5 and 3 days r e s p e c t i v e l y , Aro and McDonald, 1968) although v a r i a t i o n s can occur depending upon t i d a l a c t i o n and r i v e r flows. Based on l i m i t e d i n f o r m a t i o n , s t e e l h e a d pass through Area 4 on a d a i l y b a s i s and may take three to four days to do so. The e f f e c t s of f l u c t u a t i n g f i s h i n g e f f o r t i n Area 4 (harvest r a t e s , geartypes, f i s h i n g l o c a t i o n s , d u r a t i o n etc) on s t e e l h e a d escapement i s not w e l l understood. S e i n e r s are t y p i c a l l y abundant on l y at the height of the sockeye f i s h e r y ( l a t e J u l y ) . Normal f i s h e r y openings f o r a l l gears g e n e r a l l y occur on Sunday evenings and can l a s t from one to four or more days (24 hours/day). Department of F i s h e r i e s and Oceans c a t c h and t e s t f i s h e r y r e c o r d s f o r the years 1963 to 1984 show average catc h e s of s t e e l h e a d peaking from e a r l y to mid August j u s t a f t e r peak sockeye and j u s t p r i o r to peak pink salmon h a r v e s t s . The annual average s t e e l h e a d c a t c h f o r a l l gear types i n area 4 has been j u s t over 13,000 p i e c e s with extremes in c a t c h o c c u r r i n g i n 1966 (20,000) and a g a i n i n 1984 (31,000). The average annual harvest+escapement f o r the same time p e r i o d has been estimated 1 2 at 37,000 p i e c e s with extremes again o c c u r r i n g i n 1966 (55,000) and 1984 (85,000). F i g u r e s 2 and 3 o u t l i n e the general temporal d i s t r i b u t i o n of the commercial and t e s t f i s h e r y s t e e l h e a d catches by month. F i g u r e 4 o u t l i n e s the f l u c t u a t i n g nature of the t o t a l Skeena R i v e r s t e e l h e a d harvest+escapement f o r the years 1963 to 1984. Upstream escapement c a l c u l a t i o n s f o r s t e e l h e a d are based on Department of F i s h e r i e s and Oceans t e s t f i s h e r y i n d i c e s and m u l t i p l i c a t i o n f a c t o r s generated on best estimated escapement f i g u r e s f o r a ten or more year p e r i o d (BCFW Branch, unpublished data, 1984). Skeena R i v e r s t e e l h e a d are a l s o harvested by n a t i v e net f i s h e r i e s i n much of the Skeena i t s e l f and by major sport f i s h e r i e s i n a l l of the mainstem t r i b u t a r i e s . 13 F i g u r e 2. 1963 to 1984 mean annual s t e e l h e a d harvest by month i n Area 4. The week beginning codes are Week 7=July 1, Week 8=July 8, Week 9=Julyl5, Week lO=July 21 Week 11=July 29, Week 12=Aug 5, Week 13=Aug12 Week 14=Augl9 Week l5=Aug26 (Source, unpublished data, BCF Branch, 1984). F i g u r e 3. 1963 to 1984 mean s t e e l h e a d escapement by month through Area 4. The week beginning codes are Week 7=July 1, Week 8=July 8, Week 9=July15, Week 1U=July 22 Week 11=July 29, Week 12=Aug 5, Week 13=Aug12 Week 14=Augl9 Week l5=Aug26 (Source, unpublished data, BCF Branch, 1984). • i..-oc; i i snnnu i \mc B I / I <VT ST fcT £T ?;T T I OT 6 8 / . 15 F i g u r e 4. 1963 to 1984 mean annual s t e e l h e a d harvest+escapement i n Area 4. ( Source, unpublished data, BCF Branch, 1984). 16 * = harvest + - escapement 17 MATERIALS AND METHODS Scale Data C o l l e c t i o n and P r e p a r a t i o n Ninety to one hundred a d u l t s t e e l h e a d s c a l e samples taken in the l a t e f a l l (1975-1983) from each of the f i v e major Skeena River s t o c k s ( K i s p i o x , Zymoetz, Babine, Sustut, M o r i c e - B u l k l e y ) were s e l e c t e d from e x i s t i n g B.C. F i s h e r i e s Branch data bases for s c a l e p a t t e r n a n a l y s i s . Stock d e f i n i t i o n was l i m i t e d to the major Skeena River t r i b u t a r i e s . Most s c a l e s had been p r e v i o u s l y mounted i n a c e t a t e and represented a n g l e r caught s t e e l h e a d taken duri n g v a r i o u s F i s h e r i e s Branch p r o j e c t s . The m a j o r i t y of s c a l e s had been once read f o r age and i n c l u d e d l e n g t h , weight, and sex d a t a . These s c a l e s represented the l e a r n i n g samples f o r subsequent d i s c r i m i n a n t a n a l y s i s . S c a l e samples were s e l e c t e d from years having adequate (n>100) sample s i z e s f o r each stock; these were: K i s p i o x River 1975 n=l03, Zymoetz R i v e r 1975 n=30 1978 n=62, Morice River 1976 n=30 1977 n=60, Babine R i v e r 1978 n=9l, Sustut R i v e r 1977 n=30 1983 n=60. The a v a i l a b i l i t y of y e a r l y time s e r i e s s c a l e data f o r between years comparison was l i m i t e d . A major a p r i o r i assumption f o r t h i s study was that the e x i s t i n g data base adequately represented the true p o p u l a t i o n s t r u c t u r e of each stock. S i x t y s c a l e samples were a t t a i n e d and anal y s e d f o r each of the L a k e l s e and Kitsumkalum R i v e r s but were not used i n l a t e r d i s c r i m i n a n t analyses because of t h e i r l i k e l y winter-run o r i g i n s . P r e v i o u s l y prepared s c a l e s and those prepared by the author 18 were sampled from the p r e f e r r e d area ( C l u t t e r and W h i t e s e l , 1956) on the l e f t s i d e of each s t e e l h e a d two to four s c a l e rows above the l a t e r a l l i n e j u s t p o s t e r i o r to the d o r s a l f i n . Two nonregenerate s c a l e s were mounted in a c e t a t e f o l l o w i n g the methods of Chuganova (1963) and the two s e l e c t e d s c a l e s were then p r o j e c t e d at 34X m a g n i f i c a t i o n under a 3M m i c r o f i c h e r e a d e r - p r i n t e r . I n i t i a l ages were assigned f o l l o w i n g the c r i t e r i a of p revious workers (Maher 1954, C l u t t e r and Whitesel 1956, Maher and L a r k i n 1955, Henry 1961, Chuganova 1963, Narver 1969, Major et a l . 1972). Freshwater and f i r s t marine year s c a l e growth zones and a n n u l i were d i s t i n g u i s h e d along the p o s t e r i o r - a n t e r i o r s c a l e a x i s through the s c a l e focus (Figure 5). P r i n t s were made of one s c a l e from each s t e e l h e a d and used for subsequent a n a l y s i s . The c r i t e r i a f o r e s t a b l i s h i n g a n n u l i , f a l s e checks, freshwater p l u s growth, c i r c u l i counts, and spawning checks on each s c a l e followed the methodology of Chuganova (1963), Narver (1969), and Tanaka et a l (1969). Freshwater a n n u l i were i d e n t i f i e d by any narrowing of c i r c u l i and/or the space between c i r c u l i i n c l u d i n g c u t t i n g over of the f i r s t c i r c u l u s of new year's growth. Saltwater a n n u l i were i d e n t i f i e d as the l a s t c i r c u l u s i n a region of narrowing which preceded marked i n c r e a s e s i n c i r c u l u s spacing. Given the s u b j e c t i v e nature of s c a l e reading (Conrad, 1984), the author's aging technique was v e r i f i e d by an independent source f o r a random sample of f i f t y s c a l e s . In a d d i t i o n , a subsample of one hundred s c a l e s was reread by the author s i x months a f t e r the i n i t i a l r e ading. V a l i d a t i o n of 19 F i g u r e 5. Adult s t e e l h e a d s c a l e from the Sustut R i v e r . T o t a l age i s 3.2+. Shown i s the measurement a x i s used f o r aging and measurement of s c a l e s i n t h i s study. Each annulus i s marked by the h o r i z o n t a l l i n e s ; a region of s p r i n g p l u s growth precedes ocean entry (34X m a g n i f i c a t i o n ) . 20 21 s c a l e growth at age f o r t h i s study was not attempted. Age d e s i g n a t i o n s f o l l o w e d the methodology of Narver (1969). The time of annulus d e p o s i t i o n was taken to be March 31, a f t e r Maher (1954). As an example of age d e s i g n a t i o n , a s t e e l h e a d of age 4.1S1+ i s i n i t s seventh p l u s f u l l year of l i f e . I t spent four complete winters i n freshwater (4) before smolting to sea (.) where i t spent the next winter (1) and p a r t of the next summer i n sa l t w a t e r before r e t u r n i n g i n the f a l l and spawning (S) the next s p r i n g . I t then s u r v i v e d , migrated back to sea and spent the next winter (1) and pa r t of the next summer again i n s a l t w a t e r before r e t u r n i n g i n the f a l l (+) to p o t e n t i a l l y spawn again the next s p r i n g . A l l s c a l e s were analysed f o r four measurements and two c i r c u l i counts i n each y e a r l y freshwater s c a l e zone and i n the f i r s t marine s c a l e zone ( t a b l e 2 ) . Measurements were made to the nearest 0.01mm usi n g H e l i o s c a l i p e r s on each s c a l e p r i n t p r i n t h e l d to low power under a Wil d M5 s t e r e o microscope. The s c a l e v a r i a b l e s used i n t h i s study were s e l e c t e d f o r a n a l y s i s because of t h e i r s u c c e s s f u l use i n other s c a l e p a t t e r n s t u d i e s (Anas and Murai 1969, B i l t o n 1971, Lear and Sandeman 1980, Conrad 1984). As Skeena River s t e e l h e a d spend from one to f i v e y e a rs i n freshwater and from one to f i v e years i n s a l t w a t e r , the number of s c a l e v a r i a b l e s recorded f o r each s t e e l h e a d was dependent upon freshwater age. Only s t e e l h e a d of the dominant freshwater Skeena R i v e r age groups (3 and 4) were used i n t h i s study. One hundred seventy f i v e s c a l e samples per week were 22 Table 2. V a r i a b l e s measured from the a d u l t s t e e l h e a d s c a l e s for each stock. V a r i a b l e D e f i n i t i o n PG Presence (1) absence (2) of p l u s growth A1 Distance to second c i r c u l u s i n year 1 A2 Distance to f o u r t h c i r c u l u s i n year 1 A3 Distance to s i x t h c i r c u l u s i n year 1 A4 T o t a l width of s c a l e zone i n year 1 A5 Number of c i r c u l i h a l f across year 1 A6 Number of c i r c u l i f u l l a c ross year 1 B1 Distance to second c i r c u l u s i n year 2 B2 Distance to f o u r t h c i r c u l u s i n year 2 B3 Distance to s i x t h c i r c u l u s i n year 2 B4 T o t a l width of s c a l e zone i n year 2 B5 Number of c i r c u l i h a l f across year 2 B6 Number of c i r c u l i f u l l a c ross year 2 CI Dista n c e to second c i r c u l u s i n year 3 C2 Distance to f o u r t h c i r c u l u s i n year 3 C3 Distance to s i x t h c i r c u l u s i n year 3 C4 T o t a l width of s c a l e zone i n year 3 C5 Number of c i r c u l i h a l f a c r o s s year 3 C6 Number of c i r c u l i f u l l across year 3 D1 Di s t a n c e to second c i r c u l u s i n f i r s t ocean year D2 Di s t a n c e to f o u r t h c i r c u l u s i n f i r s t ocean year D3 Di s t a n c e to s i x t h c i r c u l u s i n f i r s t ocean year D4 T o t a l width of s c a l e zone in f i r s t ocean year D5 Number of c i r c u l i h a l f a c r o s s f i r s t ocean year D6 Number of c i r c u l i f u l l a c r o s s f i r s t ocean year E1 Distance to second c i r c u l u s i n year 4 E2 Dista n c e to f o u r t h c i r c u l u s i n year 4 E3 Distance to s i x t h c i r c u l u s i n year 4 E4 T o t a l width of s c a l e zone i n year 4 E5 Number of c i r c u l i h a l f a c r o s s year 4 E6 Number of c i r c u l i f u l l a c r o s s year 4 A d d i t i o n a l v a r i a b l e s = L Length WT Weight Sex Sex FWA freshwater age SWA sa l t w a t e r age 23 a t t a i n e d from i n c i d e n t a l l y caught s t e e l h e a d i n the s i x week area 4 commercial salmon f i s h e r y d u r i n g mid-July through August of 1984. Seiner and packer o f f l o a d s from g i l l n e t t e r s were randomly sampled at the end of each two to four day weekly f i s h e r y opening. Fork l e n g t h (to the nearest 0.5cm), weight (to the nearest 0.5kg) and sex were recorded f o r each s c a l e sample. A l l sampling was conducted at the P r i n c e Rupert p l a n t of B.C. Packers L i m i t e d . An examination of s a l e s s l i p s i n d i c t e d that 20 to 60% of the t o t a l area 4 i n c i d e n t a l c a t c h passes through B.C Packers f a c i l i t y . Attempts to use Department of F i s h e r i e s and Oceans t e s t f i s h e r y s t e e l h e a d s c a l e data f o r 1984 and past years were l i m i t e d by small sample s i z e s and a high i n c i d e n c e of regenerate s c a l e s present i n the data base. Determination of Sample S i z e s Required sample s i z e s f o r t h i s study f o l l o w e d the methodology of C l u t t e r and W h i t e s e l (1956). Using sockeye salmon as an example they showed that s c a l e sampling v a r i a t i o n c o u l d be kept to w i t h i n p l u s or minus one h a l f a c i r c u l u s of a true p o p u l a t i o n mean (95% c o n f i d e n c e l e v e l ) with a sample of s i x t y s c a l e s . Previous estimates of s c a l e p a t t e r n v a r i a n c e i n Skeena R i v e r s t e e l h e a d were not a v a i l a b l e . The author used a maximum expected standard d e v i a t i o n ( i n c i r c u l i count) from the t r u e mean i n any s c a l e zone of one. From the m o d i f i e d formula of C l u t t e r and W h i t e s e l (1956, pages 75-82) and assuming that the sample means in t h i s study were normally d i s t r i b u t e d , 95% of the sample means of s i z e n from a given stock should l i e w i t h i n 24 two standard e r r o r s of a given sample mean. For 95% of the means to l i e w i t h i n p l u s or minus one c i r c u l u s of a given sample mean, 136 s c a l e s from each stock were r e q u i r e d f o r stock s e p a r a t i o n purposes. For 90% of the means to l i e w i t h i n the same conf i d e n c e i n t e r v a l , a sample of 97 was r e q u i r e d . Sample s i z e s from the commercial f i s h e r y were d i f f i c u l t to determine because of the number of stocks i n v o l v e d , the d i v e r s e age s t r u c t u r e of s t e e l h e a d in the c a t c h , and the h i g h l y v a r i a b l e nature of the f i s h e r y . Anas and Murai (1969) u t i l i z e d Worlund's (1960) p r e c i s i o n curves (page 172) f o r maximum expected e r r o r of c l a s s i f i c a t i o n i n deducing f a v o r a b l e sample s i z e s f o r c l a s s i f y i n g sockeye salmon on the high seas. F o l l o w i n g t h e i r methodology I chose an estimated e r r o r r a t e i n c o r r e c t c l a s s i f i c a t i o n f o r Skeena R i v e r s t e e l h e a d of between 15 and 30 p e r c e n t . The weekly mixed f i s h e r y samples r e q u i r e d f o r t h i s study were then c a l c u l a t e d at between 150 and 200 (90% confidence l e v e l ) . J u v e n i l e A n a l y s i s In August of 1983, t h i r t y s t e e l h e a d parr were c o l l e c t e d by e l e c t r o s h o c k e r and seine from the lower reaches of the Morice- B u l k l e y , K i s p i o x , and Zymoetz r i v e r s r e s p e c t i v e l y . M o r p h o l o g i c a l comparisons were conducted between the j u v e n i l e s in order to assess morphological f e a t u r e s and to compare o v e r a l l body form i n the d i f f e r e n t r i v e r s . Ten body measurements, f o l l o w i n g Hubbs and L a g l e r (1967) were a t t a i n e d from each specimen. These were head l e n g t h (HL), head depth (HD), head 25 width (HW), caudal peduncle depth (CD), caud a l peduncle width (CW), body depth (BD), body width (BW), p r e d o r s a l l e n g t h (PrDL), and post d o r s a l l e n g t h (PoDL). As the parr were of v a r i o u s ages and s i z e , the e f f e c t s of a l l o m e t r y were removed by s t a n d a r d i z i n g the data to pooled grand mean standard l e n g t h (Thorpe, 1976). Log-log (base 10) r e g r e s s i o n s f o r each v a r i a b l e on standard l e n g t h were a d j u s t e d a c c o r d i n g to the c o r r e c t i o n procedure: log(y)=logy-b*(logX-logX') (1) where log(y) was the a d j u s t e d v a r i a b l e v a l u e , l o g Y was the i n i t i a l v a r i a b l e value, b was the r e g r e s s i o n c o e f f i c i e n t f o r the r e g r e s s i o n of each v a r i a b l e a g a i n s t standard l e n g t h , and l o g X' was the grand mean standard l e n g t h . A n t i l o g s ( l o g ( y ) ) were used i n a d i s c r i m i n a n t a n a l y s i s of mo r p h o l o g i c a l f e a t u r e s to assess the s e p a r a b i l i t y of j u v e n i l e s from the three systems. A n a l y t i c a l Techniques f o r Sc a l e P a t t e r n A n a l y s i s L i n e a r d i s c r i m i n a n t f u n c t i o n a n a l y s i s ( F i s h e r 1936, Dixon 1981) was a p p l i e d to the a d u l t s c a l e data f o r c a l c u l a t i n g the d e c i s i o n r u l e s f o r stock s e p a r a t i o n and c l a s s i f i c a t i o n . L i n e a r versus q u a d r a t i c d i s c r i m i n a n t a n a l y s i s was chosen because a) other s t u d i e s had used l i n e a r models s u c c e s s f u l l y b) the u n d e r l y i n g d i s t r i b u t i o n s of s c a l e p a t t e r n f e a t u r e s seemed to be normal and c) l i n e a r a n a l y s i s was r e a d i l y implementable. Models u t i l i z i n g s t e e l h e a d of the two dominant freshwater age c l a s s e s (3 and 4) were c o n s t r u c t e d using those s c a l e v a r i a b l e s which 26 were both normally d i s t r i b u t e d i n u n i v a r i a t e comparisons and which had high F scores i n one way an a l y s e s of v a r i a n c e . U n i v a r i a t e ANOVAS, m u l t i v a r i a t e ANOVAS, and the d i s c r i m i n a n t a n a l y s e s performed i n t h i s study were generated using BMDP (Dixon, 1981) software. D i s c r i m i n a n t a n a l y s i s i s a m u l t i v a r i a t e technique f o r s e p a r a t i n g and a n a l y z i n g d i f f e r e n c e s present i n p r e v i o u s l y e s t a b l i s h e d groups of o b j e c t s (Pimental, 1979). A d i s c r i m i n a n t f u n c t i o n i s the l i n e a r combination of p observed v a r i a b l e s which maximizes between group v a r i a n c e r e l a t i v e to w i t h i n group v a r i a n c e ( F i s h e r , 1936). The r a t i o n a l e f o r us i n g d i s c r i m i n a n t a n a l y s i s stems from the usual i n a b i l i t y to s t a t i s t i c a l l y d i s t i n g u i s h between known groups u s i n g u n i v a r i a t e methodology ( J o l i c o u e r , 1959). For Skeena R i v e r s t e e l h e a d , each stock r e p r e s e n t s an e s t a b l i s h e d group of known o r i g i n (a l e a r n i n g sample) i n m u l t i v a r i a t e space which can be rep r e s e n t e d by a m u l t i v a r i a t e normal p r o b a b i l i t y d e n s i t y f u n c t i o n . The l i n e a r a r r a y of s c a l e measurements ( v e c t o r ) from each s t e e l h e a d d e s c r i b e s the l o c a t i o n of th a t i n d i v i d u a l i n m u l t i v a r i a t e space. I n d i v i d u a l s t e e l h e a d from the same stock should occupy a common reg i o n i n m u l t i v a r i a t e space d e f i n e d by the d i s p e r s i o n ( v a r i a n c e - c o v a r i a n c e ) of i n d i v i d u a l s about the common stock average f o r a l l v a r i a b l e s (the stock c e n t r o i d ) . M u l t i v a r i a t e a n a l y s i s of v a r i a n c e was used t o t e s t the s i g n i f i c a n c e of d i f f e r e n c e s between stock c e n t r o i d s i n t h i s study. The r e j e c t i o n of e q u a l i t y between c e n t r o i d s i s a p r e r e q u i s i t e f o r d i s c r i m i n a n t a n a l y s i s . Appendix A o u t l i n e s the 27 methodology of d i s c r i m i n a n t a n a l y s i s as i t a p p l i e d t o t h i s s t u d y . F i g u r e 6 shows the b a s i c r e l a t i o n s h i p between e u c l i d e a n and d i s c r i m i n a n t space f o r a h y p o t h e t i c a l t h r e e v a r i a b l e , t h r e e s t o c k a n a l y s i s . 28 Figure 6. D i s c r i m i n a n t space. E u c l i d e a n three v a r i a b l e space f o r three h y p o t h e t i c a l s t e e l h e a d s t o c k s . The m u l t i v a r i a t e swarms of data p o i n t s ( i n d i v i d u a l s ) , c o n s i d e r e d one v a r i a b l e at a time, f a i l to to separate i n e u c l i d e a n space along any s i n g l e v a r i a b l e p l a n e : wx, xy, or yz. L i n e a r combinations of the o r i g i n a l v a r i a b l e s and p r o j e c t i o n of the r e s u l t i n g c a n o n i c a l v a r i a b l e s to two a x i s d i s c r i m i n a n t space best separates the groups. The + denotes c e n t r o i d s f o r each group, the ( + ) denotes the grand mean c e n t r o i d with a mean of 0 and a standard d e v i a t i o n of one i n d i s c r i m i n a n t space. 3 variab.le e u c l i d e a n space w a a + a a b b b + b b b < + ) c c c + c c c f u n c t i o n 2 f u n c t i on Two a x i s d i s c r i m i n a n t space 30 RESULTS D i s c r i m i n a t i o n of Skeena River Steelhead V e r i f i c a t i o n of s c a l e aging The s t e e l h e a d s c a l e s used i n t h i s study e x h i b t e d v a r i a b l e r e a d a b i l i t y . Some s c a l e s had to be reread two and three times because of poor annular d e f i n i t i o n and s c a l e c l a r i t y . In gen e r a l , a l l s c a l e s e x h i b i t e d narrow freshwater growth zones which o f t e n made annular placement d i f f i c u l t . S t i l l , of the f i f t y randomly s e l e c t e d s c a l e s read f o r age by an o u t s i d e source, 93% were i n agreement with the authors' d e s i g n a t i o n of age. A sample of one hundred s c a l e s reread by the author approximately s i x months a f t e r the i n i t i a l r e a d i n g r e s u l t e d i n nine s c a l e s being changed f o r d e s i g n a t i o n of age. D e s c r i p t i v e s t a t i s t i c s Age composition Age composition s t r u c t u r e w i t h i n and between each of the f i v e major Skeena River s t e e l h e a d stocks was found to be d i v e r s e (Appendix t a b l e 1 and f i g u r e 7 ) . Of the o r i g i n a l 475 s c a l e s c o l l e c t e d f o r a n a l y s i s , 466 had readable f r e s h and s a l t w a t e r s c a l e growth zones. For a l l stocks s i x dominant age c l a s s e s (3.1+, 3.2+, 3.3+, 4.1+, 4.2+, 4.3+) were evident from the data as w e l l as s i x minor ones (2.1+, 2.2+, 3.4+, 4.4+, 5.1+, 5.2+) 31 F i g u r e 7. Age composition s t r u c t u r e f o r the f i v e s t e e l h e a d stocks used i n the study. RS denotes repeat spawners (compiled from appendix t a b l e 1). AGE COMPOSITION KISPIOX RIVER : n=103 I U I I I aV x%" yV y kS* t.y »>* & AGE CLASS SUSTUT RIVER : n=90 JUuLu 1>* %V V y1-* ̂ " l>* Ll* U>* & ACE CLASS BABINE RIVER : n=91 2 O 0.4 , P._^_P-_.»-.. a>* i>* v^* y** y^* »>* kV k>* & AGE CLASS I yi> ki* k>* & AGE CLASS MORICE/BULKLEY RIVER : n=89 O £ 0.2 I 1>" i%* V>* y l * y** O* (..V »>* ^ AGE CLASS ZYMOETZ RIVER : n=92 I UJUL-JK aV V y i * y V *>* AGE CLASS 33 and s i x or seven repeat spawner age c l a s s e s (3.1S1+, 3.251+, 4.1S1+, 4.2S1+, 4.1S1S1+, 3.S1+ e t c ) . From Appendix t a b l e 1, the most common age c l a s s e s over a l l stocks were 4.2+ (31%) and 3.2+ (27%). Repeat spawners were apparent i n 12% of the t o t a l data base. Maiden spawners to the f i v e Skeena stocks had spent, on average, two (1%),three (45%) and four (54%) years i n freshwater p r i o r to smolting and one (18%), two (66%) and three (15%) years i n s a l t w a t e r p r i o r to spawning. Reduced maturation and growth r a t e s i n harsher northern environments (R i c k e r , 1972) would e x p l a i n the o l d e r freshwater ages of Skeena R i v e r s t e e l h e a d compared to southern s t e e l h e a d s t o c k s (see Shapovalov and T a f t 1954, W i t h l e r 1966, H o r n c a s t l e 1981). By s t o c k , s t e e l h e a d from the Zymoetz River were predominantly of ages 4.2+ (35%) and 3.2+ (25%); those from the K i s p i o x R i v e r were predominantly of ages 3.2+ (29%), 3.3+ (26%) and 4.2+ (25%); those from the M o r i c e - B u l k l e y River were predominantly of ages 4.1+ (43%), 4.2+ (22%) and 3.1+ (15%); those from the Babine River were predominantly of ages 3.2+ (62%) and 4.2+ (26%); and those from the Sustut R i v e r were predominantly of ages 4.2+ (50%), 4.3+ (16%), 3.2+ (13%), and 3.3+ (11%). Table 3 summarizes the age composition f e a t u r e s of each stock as read from t h e i r s c a l e s a c c o r d i n g to smolt age, ocean age, and c o n t r i b u t i o n s by sex. K i s p i o x River s t e e l h e a d had long ocean r e s i d e n c i e s (32% 3+) while those from the Morice- B u l k l e y R i v e r had r e l a t i v e l y short ocean r e s i d e n c i e s (64% 1+). 90% of the Babine River s t e e l h e a d had spent 2+ years i n the ocean while only 2% had spent three or more. . The i n c i d e n c e of 34 Table 3. Age Composition f e a t u r e s of Skeena R i v e r s t e e l h e a d by sex, smolt age, and ocean age (compiled from appendix t a b l e 1, ** denotes maiden spawners o n l y ) . PROPORTION OF STOCK FEATURE: Zymoetz Ki spiox Mor i c e Babine Sustut n = 92 n=1 03 n=90 n=9l n=90 1) a d u l t s o f : * * -smolt age 3 46% 55% 27% ' 67% 27% -smolt age 4 54% 45% 73% 33% 73% -ocean age 1+ 1 4% 7% 64% 8% 1% -ocean age 2 + 76% 61% 34% 90% 70% -ocean age 3+ 1 0% 32% 3% 2% 29% 2)repeat spawners 22% 1 4% 1 0% 2% 9% 3)sex r a t i o (f/m) 1 .2/1 1.1/1 1 .5/1 1 .8/1 1 .5/1 4)females o f : * * -ocean age 1+ 8% 1 0% 70% 7% 0% -ocean age 2+ 87% 69% 30% 91% 85% -ocean age 3+ 5% 3% 0% 2% 1 5% 5)ma1es of -ocean age 1+ 20% 4% 53% 9% 2% -ocean age 2+ 65% 55% 38% 88% 49% -ocean age 3+ 1 5% 41% 6% 3% 49% repeat spawning was h i g h e s t i n those stocks c l o s e s t to the ocean (eg Zymoetz 22%) and l e a s t i n those stocks f a r t h e s t away (eg Babine 2%). This suggests a higher i n c i d e n c e of k e l t s u r v i v a l in downstream Skeena R i v e r s t o c k s . L i m i t e d sample s i z e s made t e s t i n g the hy p o t h e s i s of w i t h i n stock age c l a s s homogeneity between years d i f f i c u l t . S e v e r a l s t u d i e s ; however, support such a t r e n d i n s t e e l h e a d (Maher 1954, Maher and L a r k i n 1955). Narver (1959) found s l i g h t d i f f e r e n c e s in the p r o p o r t i o n s of age 3.2+ s t e e l h e a d (73% i n 1967, 60% i n 1968), 3.3+ s t e e l h e a d (10% i n 1967, 23% i n 1968), and 4.2+ s t e e l h e a d (8% i n 1967, 11% i n 1968) i n the Babine R i v e r between 35 y e a r s . 62% of the Babine River s t e e l h e a d used i n t h i s study (1977) were of age 3.2+ (1% were of age 3.3+ and 26% were age 4.2+). For both the Morice and Sustut R i v e r s t e e l h e a d data used in t h i s study the p r o p o r t i o n a l dominance of the major age c l a s s e s changed l i t t l e between years (Morice-Bulkley 1976 4.1+=37% , 4.2+=24% 1977 4.1+=43% 4.2+=21%: Sustut 1977 4.2+=46% 1983 52%). Given that age at maturity has a h e r i t a b l e b a s i s i n salmonids ( R i c k e r , 1972) the age c l a s s s t r u c t u r e of Skeena R i v e r s t e e l h e a d may r e f l e c t s e l e c t i o n f o r s u c c e s s f u l r e p r o d u c t i o n i n r i v e r s p e c i f i c environments. S i z e s at age Appendix t a b l e 2 summarizes the mean s i z e s at age f o r the f i v e Skeena R i v e r s t e e l h e a d s t o c k s . S i z e at age was found to be a f u n c t i o n of s a l t w a t e r and not freshwater residence time. Both the mean lengths and weights of 3.2+ and 4.2+ s t e e l h e a d were s i m i l a r w i t h i n stocks but s i g n i f i c a n t l y d i f f e r e n t between stocks (ANOVA l e n g t h P<0.001, weight P<0.001) f o r the sexes combined ( f i g u r e s 8 and 9) and by sex alone (age 3.2+, f i g u r e 10). For a given ocean age stock d i f f e r e n c e s by sex were q u i t e pronounced; K i s p i o x R i v e r ocean age 2+ males were 11% longer (mean length= 88.3cm) and 40% heavier (mean weight =7.9kg) than Morice R i v e r ocean age 2+ males (mean length=79.4cm, mean weight=4.7kg). Over a l l stocks and ages, K i s p i o x and Sustut River s t e e l h e a d were predominantly the l a r g e s t , M o r i c e - B u l k l e y River s t e e l h e a d were predominantly the s m a l l e s t . V a r i a t i o n s i n s i z e between Skeena River s t e e l h e a d stocks 36 F i g u r e 8. Mean lengths of age 3.2+ and 4.2+ s t e e l h e a d from the f i v e stocks used i n the study. Shown are the means +/- one standard e r r o r about the mean, the 95% con f i d e n c e i n t e r v a l about the mean, and the sample s i z e f o r each age c l a s s . F i g u r e 9. Mean weights of age 3.2+ and 4.2+ s t e e l h e a d f o r the f i v e stocks used i n the study. Shown are the means +/- one standard e r r o r about the mean, the 95% con f i d e n c e i n t e r v a l about the mean, and the sample s i z e f o r each age c l a s s . 37 - i - 33 121 12 12 44 I - I - I •I- I 4 .2+ 3.2+ 4.2+ 3.2+ 4.2< I I I I 3 .2+ 4 .2+ 2+ 3 .2+ 4 . I K i s p i o x I IZymoetzI IMorIce I I B a b l n e l ISustut I R ivar and A g « 27 22 33 42 12 I -I - + - I - I I I I I I t i l l 3 . 2 • 4 .2+ 3.2+ 4.2+ 3 .2+ 4.2+ 3 . 2 » 4 .2+ 3.2+ 4.2+ I K i s p i o K l IZymootzi ; M o r i c p I I B a b i n e ! R i v e r and rtge I bustict I 38 F i g u r e 10. Mean lengths by sex f o r age 3.2+ s t e e l h e a d from the f i v e stocks used i n the study. Shown are the means +/- one standard e r r o r about the mean, the 95% confi d e n c e i n t e r v a l about the mean, and the sample s i z e .for each sex. 90- l O L E 85-! N G T H 80-! (cm) • 17 I 20 75-I 70- ! 65-1 I M M F M F M F 11 F i K i s p i o x l iZymoetzl IMorice i t Babine! River and Sex ! i M F ISustut I 40 have been noted (Whately et a l . 1978) and probably r e f l e c t g e n e t i c d i f f e r e n c e s i n ocean growth r a t e s , v a r i a b l e ocean f e e d i n g b e h a v i o r s , or both. Table 4 r e p o r t s the stock s p e c i f i c mean lengths and weights of males and females by ocean age f o r each stock use i n the study. Table 4. Mean Lengths and Weights f o r Skeena River s t e e l h e a d of v a r i o u s ocean age (standard e r r o r s about the mean a v a i l a b l e from appendix t a b l e 2). RIVER FEATURE Zymoetz K i s p i o x Mor i c e Babine S u s t LENGTH cm) 1)males: ocean age 1+ 57.3 63.5 59.0 58.8 55.9 ocean age 2+ 81.0 88.3 79.4 77.3 84.4 ocean age 3+ 94.0 97. 1 91 .5 91 .4 94.7 2)females: ocean age 1+ 64.9 57.8 56.3 60.3 63.5 ocean age 2+ 75.2 80.4 72.5 76.4 77.2 ocean age 3+ 84.2 87.3 — — 87.0 WEIGHT (kg) 1)males ocean age 1+ 2.2 2.2 1.8 2.0 1.8 ocean age 2+ 7.9 7.9 4.7 4.4 6.4 ocean age 3+ 8.1 9.6 7.4 7.4 8.9 2)females ocean age 1+ 2.6 2.4 1 .7 2.0 2.7 ocean age 2+ 4.4 5.6 3.3 4.5 4.3 ocean age 3+ 5.7 7.2 — — 6.0 Sca l e P a t t e r n Features of Skeena R i v e r s t e e l h e a d A n a l y s i s of the s c a l e v a r i a b l e s used in t h i s study r e v e a l e d them to g e n e r a l l y be normally d i s t r i b u t e d (using BMDP7D, Dixon, 1981). The f o l l o w i n g s e c t i o n s summarize only the width and 41 c i r c u l i count s c a l e f e a t u r e s found w i t h i n each s c a l e zone f o r the f i v e Skeena R i v e r s t e e l h e a d s t o c k s . I n t r a c i r c u l a r d i s t a n c e d i f f e r e n c e s , which r e f l e c t both zone widths and c i r c u l i counts, are presented s e p a r a t e l y i n the appendix summary t a b l e s . The a d u l t s t e e l h e a d of younger smolt age used i n t h i s study had both wider freshwater s c a l e zones and more c i r c u l i i n each s c a l e zone than d i d the a d u l t s of o l d e r smolt age ( f i g u r e 11), which supports the no t i o n of slower growth r a t e s i n o l d e r smolts ( R i c k e r , 1972). I t was a l s o found that a d u l t s t e e l h e a d of the same smolt age but of d i f f e r e n t ocean age had s i m i l a r w i t h i n stock freshwater s c a l e p a t t e r n f e a t u r e s . For example, K i s p i o x and Zymoetz R i v e r age 3.1+, 3.2+, and 3.3+ s t e e l h e a d e x h i b i t e d n o n s i g n i f i c a n t d i f f e r e n c e s (ANOVA P>0.10) i n y e a r l y freshwater s c a l e zone widths and c i r c u l i counts f o r each of the three age c l a s s e s w i t h i n each stock r e s p e c t i v e l y . The same was was found fo r M o r i c e - B u l k l e y River age 4.1+ and 4.2+ s t e e l h e a d (Table 5 ) . T h i s suggested that s c a l e p a t t e r n comparisons c o u l d be made usi n g a d u l t s t e e l h e a d of s i m i l a r smolt age but of pooled ocean age from each of the f i v e Skeena R i v e r s t o c k s . S c a l e f e a t u r e s of smolt age 3 a d u l t s t e e l h e a d Appendix t a b l e 3 summarizes the d e s c r i p t i v e s t a t i s t i c s f o r s c a l e growth i n a d u l t s t e e l h e a d of smolt age 3 from the f i v e Skeena R i v e r s t o c k s by pooled ocean age (3.1+, 3.2+, 3.3+ e t c ) . S i g n i f i c a n t d i f f e r e n c e s f o r the m a j o r i t y of measured s c a l e f e a t u r e s were found. Table 6 summarizes the s c a l e zone width and c i r c u l i count d i f f e r e n c e s between the f i v e s t o c k s . Both 42 F i g u r e 11. Mean s c a l e zone widths f o r s t e e l h e a d of smolt ages 3 and 4. Shown are the y e a r l y s c a l e zone means (mm) f o r a l l s t o c k s combined +/- one standard e r r o r about the mean, the 95% conf i d e n c e i n t e r v a l , and the sample s i z e s f o r each smolt age. FWA3=smolt age 3, FWA4= smolt age 4. The width of the f i r s t ocean year s c a l e zone i s given with the standard e r r o r about the mean i n b r a c k e t s . 43 FRESHWATER I OCEAN I 44 Table 5. F s t a t i s t i c s and a s s o c i a t e d p r o b a b i l i t i e s f o r one way ANOVAs w i t h i n s t o c k s f o r d i f f e r e n c e s i n mean y e a r l y freshwater s c a l e zone widths f o r v a r i o u s age c l a s s e s i n the K i s p i o x , Zymoetz, and Morice r i v e r s . (* denotes no s i g n i f i c a n t d i f f e r e n c e at the 5% l e v e l of s i g n i f i c a n c e ) . R i v e r Age c l a s s e s V a r i a b l e F D.F P compared K i s p i o x 3.1+,3.2+,3.3+ A4 0 .34 2,45 * 0.79 B4 2 .06 2,45 * 0.12 C4 1 .46 2.45 * 0.27 D4 1 .34 2,45 * 0.27 Zymoetz 3. 1 + ,3.2+,3.3 + A4 0 .54 2,33 * 0.66 B4 1 .51 2,33 * 0.23 C4 2 .20 2,33 * 0.11 D4 2 .10 2,33 * 0.12 Morice 4.1+, 4.2+ A4 0 .25 1 ,62 * 0.78 B4 1 .19 1 ,62 * 0.31 C4 0 .89 1 ,62 * 0.78 D4 1 .34 1 ,62 * 0.27 E4 0 .21 1 ,62 * 0.80 s c a l e zone widths and c i r c u l i counts i n the second year d i f f e r e d the most between the f i v e s t o c k s . F i g u r e s 12 and 13 summarize these d i f f e r e n c e s g r a p h i c a l l y . A d u l t s of smolt age 3 from the M o r i c e - B u l k l e y R i v e r had the widest f i r s t year s c a l e zones while a d u l t s from the Zymoetz R i v e r had the s m a l l e s t f i r s t year s c a l e zones. T h i s suggests e i t h e r e a r l i e r emergence times and/or b e t t e r f i r s t year growth i n p r o d u c t i v e r e a r i n g environments f o r the former and v i c e v e r s a f o r the l a t t e r . I n t e r e s t i n g l y , both s c a l e zone widths ( f i g u r e 12) and s c a l e zone c i r c u l i counts ( f i g u r e 13) decreased markedly i n M o r i c e - B u l k l e y R i v e r smolt age 3 a d u l t s a f t e r the f i r s t year of growth. T h i s was the onl y stock to show such a t r e n d and suggests e i t h e r h i g h competition f o r food or displacement of parr i n t o areas of l e s s 45 F i g u r e 12. Y e a r l y freshwater s c a l e zone widths i n a d u l t s t e e l h e a d of smolt age 3 by pooled ocean age. Shown are the means and the 95% conf i d e n c e i n t e r v a l about the means. F i g u r e 13. Y e a r l y freshwater s c a l e zone c i r c u l i counts i n s t e e l e a d of smolt age 3 by pooled ocean age. Shown are the means and the 95% confidence i n t e r v a l about the means. R i v e r and Y e a r l y S c a l e Zone 47 Table 6. F s t a t i s t i c s and a s s o c i a t e d p r o b a b i l i t i e s f o r one way ANOVAS between stocks f o r smolt age 3 ste e l h e a d by pooled ocean age (* no s i g n i f i c a n t d i f f e r e n c e at the 5% l e v e l of s i g n i f i c a n c e ) ) V a r i a b l e DF=4,186 F P A4: year 1 width. 3.80 P<0. 02 B4: year 2 width. 8.18 P<0. 001 C4: year 3 width. 4.50 P<0. 005 D4: 1st ocean " . 1 .67 *P>0. 20 A5: year 1 c i r c . 6.26 P<0. 005 B5: year 2 c i r c . 6.48 P<0. 001 C5: year 3 c i r c . 5.59 P<0. 001 D5: 1st ocean " . 1 .67 *P>0. 20 p r o d u c t i v i t y . Conversely, Babine R i v e r a d u l t s t e e l h e a d of smolt age 3 showed l a r g e incremental s c a l e growth between years ( f i g u r e s 12 and 13) which suggests parr growth i n h i g h l y p r o d u c t i v e environments. Scale p a t t e r n f e a t u r e s (zone widths and c i r c u l i counts) were most s i m i l a r i n a d u l t smolt age 3 st e e l h e a d from the K i s p i o x and Zymoetz r i v e r s ( f i g u r e s 12 and 13) which suggests growth i n comparable environments. Scale growth i n the f i r s t marine year was not s i g n i f i c a n t l y d i f f e r e n t between the f i v e Skeena River stocks f o r a d u l t s of smolt age 3 (ANOVA: widths 0.10 <P< 0.20, c i r c u l i counts 0.20 <P< 0.50). T h i s may be a t t r i b u t a b l e to a l a r g e l e v e l of w i t h i n stock v a r i a n c e f o r marine growth i n st e e l h e a d of d i f f e r e n t ocean ages. I n v a r i a b l y , the author found the widths of the f i r s t marine zone i n 3.1+ s t e e l h e a d to be notably narrower than those of age 3.3+ st e e l h e a d from the same stock. T h i s suggests f a s t e r maturation r a t e s i n the younger a d u l t s and would r e s u l t i n n o n s i g n i f i c a n t d i f f e r e n c e s between the stocks when combining the 48 ages in a pooled ocean age a n a l y s i s . Between stock comparisons of f i r s t marine year s c a l e growth may be v a l i d only when i n d i v i d u a l s of the same ocean age are used. I n t e r e s t i n g l y , s t e e l h e a d of smolt age 4 showed the o p p o s i t e t r e n d . Scale f e a t u r e s of smolt age 4 a d u l t s t e e l h e a d Appendix t a b l e 4 summarizes the d e s c r i p t i v e s t a t i s t i c s f o r s c a l e growth in a d u l t s t e e l h e a d of smolt age 4 from the f i v e Skeena R i v e r stocks by pooled ocean age (4.1+, 4.2+, 4.3+ e t c ) . S i g n i f i c a n t d i f f e r e n c e s f o r the m a j o r i t y of measured s c a l e f e a t u r e s were found. Table 7 summarizes the F s t a t i s t i c s generated f o r the s c a l e zone width and c i r c u l i count d i f f e r e n c e s between the f i v e s t o c k s i n a one way a n a l y s i s of v a r i a n c e f o r a d u l t s of smolt age 4. F i r s t year c i r c u l i counts and the widths of the f o u r t h year d i f f e r e d the most between the f i v e s t o c k s . From the F s c o r e s , a d u l t s t e e l h e a d of smolt age 4 were more d i f f e r e n t between the f i v e stocks than were a d u l t s of smolt age 3. The slower growth r a t e s and longer r e s i d e n c e times of 4 year o l d s may enhance stock d i f f e r e n t i a t i o n by s c a l e p a t t e r n a n a l y s i s . F i g u r e s 14 and 15 summarize the between stock d f f e r e n c e s f o r s c a l e widths and c i r c u l i counts i n a d u l t s of smolt age 4 and pooled ocean age g r a p h i c a l l y . Incremental s c a l e zone growth (widths and c i r c u l i counts) was again l a r g e i n the f i r s t year and s m a l l i n subsequent years f o r Morice R i v e r s t e e l h e a d . Sustut River a d u l t s of smolt age 4 showed wide i n c r e m e n t a l s c a l e growth zones duri n g a l l freshwater y e a r s . Wider but fewer c i r c u l i were 49 F i g u r e 14. Y e a r l y freshwater s c a l e zone widths i n a d u l t s t e e l h e a d of smolt age 4. Shown are the means and the 95% c o n f i d e n c e i n t e r v a l about the means. F i g u r e 15. Y e a r l y freshwater s c a l e zone c i r c u l i counts i n a d u l t s t e e l h e a d of smolt age 4. Shown are the means and the 95% conf i d e n c e i n t e r v a l about the means. 50 . 40- n=37 n=4B n=65 n=30 n=5<? W I D T H (mm) . 30- . 20- 1/ !./! V 15-I 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 Kispiox Zymoetz Morice Babine Sustut River and Yearly Scale Zone I n=37 n=4B n=65 n=30 n=59 ! 5-1 i i 0 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 Kispiox Zymoetz Morice Babine Sustut River and Yearly Scale Zone 51 Table 7. F s t a t i s t i c s and a s s o c i a t e d p r o b a b i l i t i e s f o r one way ANOVAS between s t o c k s f o r smolt age 4 s t e e l h e a d by pooled ocean age (* no s i g n i f i c a n t d i f f e r e n c e at the 5% s i g n i f i c a n c e l e v e l ) V a r i a b l e DF=4,234 F P A4: B4: C4: D4: E4: A5: B5: C5: D5: E5: year 1 width year 2 width year 3 width 1st ocean " year 4 width year 1 #circ year 2 #circ year 3 #circ 1st ocean " year 4 #circ 8.61 7.40 7.64 4.32 1 2.82 18.45 3.40 0.93 5.79 4.99 P<0.001 P<0.001 P<0.001 P<0.005 P<0.001 P<0.001 P<0.05 *P>0.50 P<0.001 P<0.002 apparent i n K i s p i o x River smolt age 4 st e e l h e a d a f t e r the f i r s t year ( f i g u r e 15) even though the s c a l e zones were i n c r e a s i n g i n width ( f i g u r e 14). K i s p i o x and Zymoetz River a d u l t s of smolt age 4 again had s i m i l a r p a t t e r n s of s c a l e zone growth. In c o n t r a s t to the r e s u l t s of the p r e v i o u s s e c t i o n , f i r s t marine year s c a l e growth (width) was s i g n i f i c a n t l y d i f f e r e n t between the f i v e ' Skeena R i v e r stocks f o r a d u l t s t e e l h e a d of smolt age 4 (ANOVA width P<0.05, c i r c u l i count P<0.05). T h i s suggests l e s s w i t h i n stock v a r i a n c e of f i r s t year marine growth between smolt age 4 a d u l t s of d i f f e r e n t ocean age than f o r smolt age 3 a d u l t s . V a r i a b l e f e e d i n g and/or m i g r a t i o n a l p a t t e r n s f o r 4 vs 3 year o l d smolts from each stock may e x p l a i n the d i f f e r e n c e s . Healey (1983) notes that d i f f e r e n t "types" of salmonid smolts (by stock, s i z e , age, e t c ) may respond c h a r a c t e r i s t i c a l l y to marine environments by growing d i f f e r e n t l y or s i m i l a r i l y . 52 Scale f e a t u r e s of age 3.2+ and 4.2+ s t e e l h e a d Skeena River s t e e l h e a d of s p e c i f i c age were a l s o analyzed to a ssess stock d i f f e r e n c e s i n s c a l e p a t t e r n f e a t u r e s . Age s p e c i f i c stock i d e n t i f i c a t i o n i s u s u a l l y d e s i r a b l e so as to remove any p o s s i b l e v a r i a t i o n s i n s c a l e growth a t t r i b u t a b l e to v a r i a t i o n s i n age. However, as noted p r e v i o u s l y , freshwater s c a l e growth was found to vary n o n s i g n i f i c a n t l y i n s t e e l h e a d of d i f f e r e n t ocean age. S t i l l , the two dominant s t e e l h e a d age c l a s s e s (3.2+, 4.2+) were analyzed to s a t i s f y general methodology and to b e t t e r compare s c a l e growth i n the f i r s t marine year. Appendix t a b l e s 5 and 6 summarize the u n i v a r i a t e s t a t i s t i c s f o r s c a l e f e a t u r e s i n age 3.2+ and 4.2+ s t e e l h e a d from each of the f i v e Skeena R i v e r s t o c k s . The r e s u l t s of one way a n a l yses of v a r i a n c e f o r d i f f e r e n c e s i n c e r t a i n s c a l e f e a t u r e s are summarized i n t a b l e 8 f o r the two age c l a s s e s r e s p e c t i v e l y . F i g u r e s 16 and 17 summarize the between stock d i f f e r e n c e s f o r s c a l e zone widths alone. S i g n i f i c a n t between stock d i f f e r e n c e s were found i n a l l zones except f o r c i r c u l i counts in years two and three f o r age 4.2+ s t e e l h e a d and, i n t e r e s t i n g l y , f i r s t marine year widths in both age 3.2+ and 4.2+ s t e e l h e a d . F i g u r e s 16 and 17 show that the zone d i f f e r e n c e s were s i m i l a r to those of the pooled ocean age a n a l yses ( F i g u r e s 12 and 14). Concerning the n o n s i g n i f i c a n t d i f f e r e n c e s i n f i r s t marine year widths f o r 3.2+ and 4.2+ s t e e l h e a d , t h i s r e s u l t suggests comparable between stock s c a l e growth i n the f i r s t ocean year. However, the numbers of c i r c u l i ( t a b l e 8) and the d i s t a n c e s to 53 F i g u r e 16. Y e a r l y freshwater s c a l e zone widths i n s t e e l h e a d of age 3.2+. Shown are the means and the 95% con f i d e n c e i n t e r v a l about the means. F i g u r e 17. Y e a r l y freshwater s c a l e zone widths i n s t e e l h e a d of age 4.2+. Shown are the means and the 95% con f i d e n c e i n t e r v a l about the means. 54 River and Yearly Scale Zone 55 Table 8. F s t a t i s t i c s and a s s o c i a t e d p r o b a b i l i t i e s f o r one way ANOVAS between stocks f o r age 3.2 + and 4.2+ freshwater and f i r s t marine year s c a l e zone widths and c i r c u l i counts (* i n d i c a t e s no s i g n i f i c a n t d i f f e r e n c e at the 5% s i g n i f i c a n c e l e v e l ) . V a r i a b l e Age 3. F 2+ DF= P 4, 1 36 Age 4. F 2+ DF= P 4, 185 A4: year 1 width 3. 97 P<0. 01 7. 41 P<0. 001 B4: year 2 width 6. 64 P<0. 001 4. 75 P<0. 005 C4: year 3 width 5.' 68 P<0. 001 2. 93 P<0. 05 D4: 1st ocean " 2. 68 *P>0. 05 0. 1 6 *P>0. 50 E4: year 5 width -- -- 1 1 . 25 P<0. 001 A5: year 1 c i r c . 5. 22 P<0. 002 18. 93 P<0. 001 B5: year 2 c i r c . 5. 15 P<0. 002 2. 75 *P,0. 10 C5: year 3 c i r c . 8. 22 P<0. 001 0. 79 *P<0. 50 D5: 1st ocean " 3. 06 P<0. 05 4. 46 P<0. 005 E5: year 5 width -- — 5. 26 P=0. 001 c i r c u l i i n the f i r s t marine zone ( v a r i a b l e s D1, D2, and D3) were a l l s i g n i f i c a n t l y d i f f e r e n t between the s t o c k s . These r e s u l t s are d i f f i c u l t to e x p l a i n . E i t h e r y e a r l y v a r i a t i o n s i n ocean growth are being r e f l e c t e d i n the data base or, a l t e r n a t i v e l y , the d i f f e r e n c e s are r e a l and r e f l e c t stock s p e c i f i c g e n e t i c and/or fe e d i n g d i f f e r e n c e s . S c ale p a t t e r n v a r i a t i o n between years Comparisons were made to assess the degree of s c a l e p a t t e r n v a r i a t i o n w i t h i n stocks between years even though s t e e l h e a d of d i f f e r e n t ages (eg 3.1+, 3.2+,3.3+ e t c ) , and thus brood years, sampled i n the same year e x h i b i t e d n o n - s i g n i f i c a n t d i f f e r e n c e s . Sustut R iver s t e e l h e a d of smolt age 4 (1977 n=24, 1983 n=38) and Zymoetz River a d u l t s t e e l h e a d of smolt age 3 (1975 n=l9 1978 n=20) r e v e a l e d s i g n i f i c a n t between years d i f f e r e n c e s ( t a b l e 9) 56 o n l y f o r second year and f i r s t marine year s c a l e growth i n the S u s t u t River stock. While i t i s . d i f f i c u l t to draw strong T a b l e 9. R e s u l t s of one way ANOVA'S f o r between years d i f f e r e n c e s i n s c a l e growth f o r Sustut R i v e r smolt age 4 and Zymoetz R i v e r smolt age 3 a d u l t s t e e l h e a d A=Sustut 1977 n=24, 1978 n-38 B=Zymoetz 1975 n=l9 1978 n=20 (* no s i g n i f i c a n t d i f f e r e n c e at the 5% l e v e l ) S c a l e V a r i a b l e df 1,60 (A) df 1,39 (B) A4 A5 B4 B5 C4 C5 D4 D5 E4 E5 F .03 .16 4.25 5.92 .04 .04 17.68 15.22 2.23 5.71 P .85 * .69 * .04 .02 .84 * .85 * <. 00 1 <. 00 1 . 14 * .02 F .95 1 .59 2.85 .01 .00 .17 .04 1 .62 - - P .33 * .23 * .10 * .92 * .97 * .69 * .84 * .21 * - - c o n c l u s i o n s from these r e s u l t s , small y e a r l y v a r i a t i o n s i n s c a l e f e a t u r e s may be expected i n a l l Skeena R i v e r s t e e l h e a d stocks i f r e a r i n g c o n d i t i o n s remain f a i r l y s t a b l e between y e a r s . As an index of environmental s t a b i l i t y , an examination of flow r a t e d a t a r e v e a l e d c o n s i d e r a b l e v a r i a t i o n between years f o r each of the f i v e major Skeena R i v e r t r i b u t a r i e s . The i n f l u e n c e of such f l u c t u a t i o n s on instream p r o d u c t i v i t y and s c a l e growth i s not known. For t h i s study the primary concern was that any changes i n s c a l e p a t t e r n growth between years w i t h i n s t o c k s be s m a l l e r than the changes in s c a l e p a t t e r n growth between years between s t o c k s . 57 Plus growth The i n c i d e n c e of freshwater p l u s growth p r i o r to onset of the f i r s t ocean year was h i g h e s t i n s t e e l h e a d from the K i s p i o x (35.6%) and M o r i c e - B u l k l e y (33.3%) r i v e r s f o l l o w e d by the Babine (21.7%), Sustut (20.7%), and Zymoetz (20.6%) r i v e r s r e s p e c t i v e l y . Plus growth r e f l e c t s r a p i d growth to smolt s i z e and may d i f f e r between stocks (and between years) a c c o r d i n g to the l e v e l of m a t u r i t y reached i n the l a s t freshwater year. While s i g n i f i c a n t trends were not r e a d i l y apparent, Skeena R i v e r a d u l t s t e e l h e a d of smolt age 3 tended to show a higher i n c i d e n c e of p l u s growth than d i d a d u l t s of smolt age 4. Stock D i s c r i m i n a t i o n Twelve d i s c r i m i n a n t a n a l y s i s models were c o n s t r u c t e d i n t h i s study f o r s e p a r a t i n g the f i v e Skeena R i v e r s t e e l h e a d s t o c k s . As the m a j o r i t y of s c a l e v a r i a b l e s used were normally d i s t r i b u t e d , the assumption of m u l t i v a r i a t e n o r m a l i t y was accepted. The n u l l h y p o t h e s i s of equal d i s p e r s i o n matrix e q u a l i t y was r e j e c t e d f o r s e v e r a l of the models, a f i n d i n g o f t e n observed by other workers (Conrad, 1984). However, d i s c r i m i n a n t a n a l y s i s i s s t i l l j u s t i f i e d i n most cases because of the power of MANOVA i n d e t e c t i n g s i g n i f i c a n t ' and n o n s i g n i f i c a n t d i f f e r e n c e s between groups (Pimental, 1979). 58 Separate freshwater age d i s c r i m i n a n t models F i g u r e 18 summarizes the r e s u l t s of a f i v e stock d i s c r i m i n a n t a n a l y s i s using Skeena River a d u l t s t e e l h e a d of smolt age 3 and pooled ocean age. Only s c a l e v a r i a b l e s are i n c l u d e d . M u l t i v a r i a t e a n a l y s i s of v a r i a n c e i n d i c a t e d h i g h l y s i g n i f i c a n t d i f f e r e n c e s among c e n t r o i d s f o r the the f i v e stocks (approximate F= 5.24 DF= 40 676 P<0.001). P a i r w i s e comparison of c e n t r o i d s showed that a l l ten comparisons were s i g n i f i c a n t (range of F= 3.76-7.98 DF= 10 178). The four c a n o n i c a l f u n c t i o n s accounted f o r 38.5%, 36.3%, 17.8%, and 7.4% of the e x p l a i n e d between stock v a r i a n c e r e s p e c t i v e l y . Ten of the o r i g i n a l twenty four s c a l e v a r i a b l e s were s e l e c t e d f o r f u n c t i o n c o n s t r u c t i o n , the four best d i s c r i m i n a t i n g v a r i a b l e s being B1, C1, C2, and A2. From f i g u r e 18, the f i r s t d i s c r i m i n a n t f u n c t i o n p r i m a r i l y separated K i s p i o x and Sustut River s t e e l h e a d on the b a s i s of d i s t a n c e s to the second c i r c u l u s i n years two and t h r e e . As p r e v i o u s l y noted, Sustut River s t e e l h e a d of smolt age 3 had much wider s c a l e zones than d i d K i s p i o x R i v e r s t e e l h e a d of smolt age 3, t h i s best being r e f l e c t e d by the i n t e r z o n e c i r c u l i d i s t a n c e s . T h e second d i s c r i m i n a n t f u n c t i o n p r i m a r i l y separated Babine from M o r i c e - B u l k l e y River steelhead on the b a s i s of s c a l e v a r i a b l e s C1 and A2. The pr o x i m i t y of c e n t r o i d s i n f i g u r e 18 ( e s p e c i a l l y of the K i s p i o x to the Zymoetz) p o r t r a y s the r e l a t i v e l y high degree of s c a l e v a r i a b l e o v e r l a p between the f i v e stocks f o r s t e e l h e a d of smolt age 3. P a i t w i s e comparisons r e v e a l e d that the p a t t e r n s of freshwater s c a l e growth i n smolt age 3 a d u l t s were most s i m i l a r f o r the Sustut to Zymoetz, 59 F i g u r e 18. D i s c r i m i n a n t f u n c t i o n a n a l y s i s d e s c r i b i n g s c a l e p a t t e r n v a r i a t i o n in a d u l t s t e e l h e a d of smolt age 3. The l e t t e r s i n d i c a t e the stock c e n t r o i d s S=Sustut Z=Zymoetz K=Kispiox M=Morice B=Babine *=grand c e n t r o i d , the open c i r c l e s i n d i c a t e the 90% conf i d e n c e i n t e r v a l about each c e n t r o i d (from Pimental, 1979), and the l i n e s p o i n t to the next most s i m i l a r stock i n d i s c r i m i n a n t space. The f i r s t two s t a n d a r d i z e d d i s c r i m i n a n t f u n c t i o n s are given below. D1 = -37.23C2 +61.33C1 +0.19A5 +0.50B4 -27.19A2 +69.28B1 +0.27PG -24.17B3 +5.80D3 +25.50A1 -0.12 D2 = 25.01C2 -58.24C1 -0.09A5 -.83B4 +29.27A2 -26.15B1 +0.28PG +0.11B3 -7.04D3 -24.49A1 -4.12 60 - 2 . 0 - 2 . 0 - 1 . 5 -1.0 - 0 . 5 0 + 0 . 5 +1.0 +1.5 FUNCTION 1 61 Zymoetz to K i s p i o x , K i s p i o x to Zymoetz, Babine to K i s p i o x , and M o r i c e - B u l k l e y to K i s p i o x s t o c k s . Using Lachenbruch's (1975) holdout procedure, 45.3% (range Zymoetz 29%-Sustut 69%) of the smolt age 3 a d u l t s were c o r r e c t l y c l a s s i f i e d to stock of o r i g i n (Table 10) by the c l a s s i f i c a t i o n technique. F i g u r e 19 summarizes the r e s u l t s of a f i v e stock d i s c r i m i n a n t a n a l y s i s using Skeena River a d u l t s t e e l h e a d of smolt age 4 and pooled ocean age. Only s c a l e v a r i a b l e s are i n c l u d e d . M u l t i v a r i a t e a n a l y s i s of v a r i a n c e again i n d i c a t e d h i g h l y s i g n i f i c a n t d i f f e r e n c e s among c e n t r o i d s f o r the f i v e s tocks (approximate F= 7.48 DF= 52 861 P<0.001). A l l p a i r w i s e comparisons between the f i v e stocks were s i g n i f i c a n t (range of F= 2.04-14.87 DF= 13 222). The f i r s t two c a n o n i c a l f u n c t i o n s accounted f o r 50.5% and 26.1% of the e x p l a i n e d between stock v a r i a b i l i t y (17.6% and 5.7% f o r the t h i r d and f o u r t h f u n c t i o n s r e s p e c t i v e l y ) . T h i r t e e n of the o r i g i n a l t h i r t y s c a l e v a r i a b l e s were s e l e c t e d f o r f u n c t i o n c o n s t r u c t i o n , the four best d i s c r i m i n a t i n g v a r i a b l e s being C1, B1, C3, and B3. From f i g u r e 19, the f i r s t d i s c r i m i n a n t f u n c t i o n p r i m a r i l y separated a d u l t s of smolt age 4 from the Sustut and M o r i c e - B u l k l e y R i v e r s as being the most d i s t i n c t l y d i f f e r e n t , again p r i m a r i l y on the b a s i s of d i s t a n c e s to the second c i r c u l u s i n years two and three ( l a r g e i n the Sustut, small i n the M o r i c e - B u l k l e y ) . K i s p i o x and Zymoetz R i v e r s t e e l h e a d were again found to be the most s i m i l a r . The second d i s c r i m i n a n t f u n c t i o n p r i m a r i l y separated Babine River s t e e l h e a d from the other four stocks on the b a s i s of v a r i a b l e s C3 and B3. Pairw i s e comparisons r e v e a l e d that the 62 •s A I? UiSi 1 ! !l« V I s : l - 5 5 S 5 s i l . . . . . o b I J 3 i - 2 S S 3 2 I553-S5S55 u« §1 2=SS2SS 33 It Si 52521 3 S3 S-5SSS5 11 i -s==is 1! "5 SeESSSS f a -S ISS? Id I-=sS2s Hi ? § S s = s ' is=i I; 1 C •A SSsrs | - i ! i £ S i« 3 : : : : : 5 E-2 I a; si I. -I! i c I l-ssssi a q 5-55=55 1?5 - « S s s I 1 i.:; 2^ -*a5Si | - - s s ? s s !J! 1 I ri *-S2s5a "r̂ §=? J I-5S5S5 "1 ^ « r- - r- * J: 5 - ' . -=531= n i i ! u U 4) m > C K c 4-1 -V to O >i cn cn cu in o rtj rH u u • 4J C <0 O -ri E 4J cn C D IJ o m o •rH cn 4J 3 »M ro o u in •r-t rH Jtf •<H T3 in in (0 rH U U3 I O O 4J 6 in 4-> O C 4-> C t> •<H (0 E CD •H . C V4 rH U CU cn 0) • n 4J TJ in 1 in o> rH Numbering error . Text f o r l e a f 63 not a v a i l a b l e . 64 F i g u r e 19. D i s c r i m i n a n t f u n c t i o n a n a l y s i s d e s c r i b i n g s c a l e p a t t e r n v a r i a t i o n i n a d u l t s t e e l h e a d of smolt age 4. The l e t t e r s i n d i c a t e the stock c e n t r o i d s S=Sustut Z=Zymoetz K=Kispiox M=Morice B=Babine *=grand c e n t r o i d , the open c i r c l e s i n d i c a t e the 90% confi d e n c e i n t e r v a l about each c e n t r o i d (from Pimental, 1979), and the l i n e s p o i n t to the next most s i m i l a r stock i n d i s c r i m i n a n t space. The f i r s t two s t a n d a r d i z e d d i c r i m i n a n t f u n c t i o n s are given below. D1 = -9.61E3 +0.15A5 +0.09D5 +8.50D3 -15.24B3 +24.92B1 -6.28E4 -22.50C3 +33.68C1 +0.13B6 +0.13E5 +1.52A4 -0.19D6 +0.89 D2 = -1.30E3 -0.05A5 +0.01D5 +0.42D3 -1.61B3 -1.00B1 -0.41E4 -2.22C3 +0.87C1 +0.01B6 -1.02E5 +0.07A4 -0.01D6 +5.64 + 1 .5- - 2 . 0 • i i i i i i i i • i i I I i i i - 2 . 0 - 1 . 5 - 1 . 0 - 0 . 5 0 +0.5 +1.0 +1.5 F U N C T I O N 1 66 p a t t e r n s of freshwater s c a l e growth i n smolt age 4 a d u l t s were most s i m i l a r f o r the Sustut to Zymoetz, Zymoetz to K i s p i o x , K i s p i o x to Zymoetz, Babine to M o r i c e - B u l k l e y , and M o r i c e - B u l k l e y to Babine s t o c k s . Using Lachenbruch's (1975) holdout procedure, 58.2% (range Zymoetz 40%-Sustut 71%) of the smolt age 4 Skeena a d u l t s were c o r r e c t l y c l a s s i f i e d to stock of o r i g i n (Table 11). The i n c l u s i o n of s i z e r e l a t e d data ( l e n g t h and weight) in the d i s c r i m i n a n t a n a l y s e s f o r smolt age 3 and 4 Skeena i n c r e a s e d stock d i s c r i m i n a n c e . T h i s was not too s u p r i s i n g as the f i v e stocks were shown to d i f f e r g r e a t l y with respect to s i z e s at age. 57.1% (range Zymoetz 38%-Sustut 65%) of the smolt age 3 Skeena a d u l t s and 58.6% (range Zymoetz 50%-Sustut 66%) of the smolt age 4 Skeena a d u l t s were c o r r e c t l y c l a s s i f i e d ( t a b l e s 12 and 13) to stock of o r i g i n with the i n c l u s i o n of l e n g t h and weight data. F i g u r e 20 summarizes the r e s u l t s of a f i v e stock d i s c r i m i n a n t a n a l y s i s u sing Skeena R i v e r a d u l t s of age 3.2+ based on s c a l e v a r i a b l e s a l o n e . The r e s u l t s were s i m i l a r to the smolt age 3/pooled age a n a l y s i s . Again, s i g n i f i c a n t d i f f e r e n c e s were found among the c e n t r o i d s f o r the f i v e stocks (approximate F= 7.02 DF= 40 483 P<0.001) by m u l t i v a r i a t e a n a l y s i s of v a r i a n c e and i n a l l p a i r w i s e comparisons between s t o c k s . C l a s s i f i c a t i o n accuracy f o r the age 3.2+ d i s c r i m i n a n t model was 51.8% (range Zymoetz 26%-Babine 71%) using s c a l e v a r i a b l e s alone and 61% using s c a l e v a r i a b l e s i n c o n j u n c t i o n with s i z e r e l a t e d data (range Zymoetz 38%-Babine 72%) (Table 13A). Using s c a l e v a r i a b l e s alone Sustut, Babine and M o r i c e - B u l k l e y River age 3.2+ 67 F i g u r e 20. D i s c r i m i n a n t f u n c t i o n a n a l y s i s d e s c r i b i n g s c a l e p a t t e r n v a r i a t i o n i n s t e e l h e a d of age 3.2+. The l e t t e r s i n d i c a t e the stock c e n t r o i d s S=Sustut Z=Zymoetz K=Kispiox M=Morice B=Babine *=grand c e n t r o i d , the open c i r c l e s i n d i c a t e the 90% co n f i d e n c e i n t e r v a l s about each c e n t r o i d (from Pimental, 1979), and the l i n e s p o i n t to the next most s i m i l a r stock i n d i s c r i m i n a n t space. The f i r s t two s t a n d a r d i z e d d i s c r i m i n a n t f u n c t i o n s are given below. D1 = +0.07C5 +0.01A5 +26.06C2 +13.90B1 -16.62A2 -0.03D5 +1.08D4 -0.08B5 +0.42B6 +5.26A1 -8.2 D2 = +0.02C5 -0.01A5 -4.28C2 +17.26B1 -10.02A2 +0.05D5 -0.35D4 -0.07B5 +0.11B6 +9.55A1 -0.4 - 1 . 5 - i - 2 . 0 i i i i i i i > i i i i i I I i - 2 . 0 - 1 . 5 - 1 . 0 - 0 . 5 0 +0.5 +1.0 +1.5 F U N C T I O N 1 69 s t e e l h e a d were separated along the f i r s t c a n o n i c a l f u n c t i o n ( f i g u r e 20) p r i m a r i l y by s c a l e v a r i a b l e s C2 and A2 while the second c a n o n i c a l f u n c t i o n p r i m a r i l y separated the stocks on the b a s i s of v a r i a b l e B1. P a i r w i s e comparisons r e v e a l e d that the p a t t e r n s of freshwater s c a l e growth i n age 3.2+ s t e e l h e a d were most s i m i l a r f o r the Sustut to Zymoetz, Zymoetz to K i s p i o x , K i s p i o x to Zymoetz, Babine to K i s p i o x , and M o r i c e - B u l k l e y to K i s p i o x s t o c k s . F i g u r e 21 summarizes the r e s u l t s of a f i v e stock d i s c r i m i n a n t a n a l y s i s u s i n g Skeena River s t e e l h e a d of age 4.2+. S i g n i f i c a n t d i f f e r e n c e s between stock c e n t r o i d s (approximate F= 6.91 DF= 44 671 P<0.001) and i n a l l p a i r w i s e comparisons were again e v i d e n t from m u l t i v a r i a t e a n a l y s i s of v a r i a n c e . C l a s s i f i c a t i o n accuracy f o r the age 4.2+ model was 55.3% (range Zymoetz -40%-Sustut 70%) u s i n g s c a l e v a r i a b l e s alone and 59.5% (range Zymoetz 44%-Sustut 71%) (Table 13B) using s c a l e v a r i a b l e s i n c o n j u n c t i o n with s i z e r e l a t e d d a t a . Using s c a l e v a r i a b l e s alone, Sustut, Morice and Babine River age 4.2+ s t e e l h e a d were separated along the f i r s t c a n o n i c a l f u n c t i o n ( f i g u r e 21) p r i m a r i l y ~ by s c a l e v a r i a b l e s C1 and B1 while the second c a n o n i c a l f u n c t i o n p r i m a r i l y separated the stocks on the b a s i s of v a r i a b l e C3 ( f i g u r e 21). P a i r w i s e comparisons r e v e a l e d that the p a t t e r n s of freshwater s c a l e growth i n age 4.2+ s t e e l h e a d were most s i m i l a r f o r the Sustut to Zymoetz, Zymoetz to K i s p i o x , K i s p i o x to Zymoetz, Babine to M o r i c e - B u l k l e y , and M o r i c e - B u l k l e y to Babine s t o c k s . 70 F i g u r e 21. D i s c r i m i n a n t f u n c t i o n a n a l y s i s d e s c r i b i n g s c a l e p a t t e r n v a r i a t i o n i n s t e e l h e a d of age 4.2+. The l e t t e r s i n d i c a t e the stock c e n t r o i d s S=Sustut Z=Zymoetz K=Kispiox M=Morice B=Babine *=grand c e n t r o i d , the open c i r c l e s i n d i c a t e the 90% co n f i d e n c e i n t e r v a l about each c e n t r o i d (from Pimental, 1979), and the l i n e s p o i n t to the next most s i m i l a r stock i n d i s c r i m i n a n t space. The f i r s t two s t a n d a r d i z e d d i s c r i m i n a n t f u n c t i o n s are given below. D1 = +0.21A5 -9.31E3 +9.73D3 +0.05D5 -24.11B3 +39.69B1 -3.32E4 -24.14C3 +46.52C1 +0.15A6 + 0.73 D2 = -0.09A5 -0.48E3 -0.35D3 +0.01D5 -0.46B3 -0.02B1 -0.30E4 +1.26C3 -0.76C1 +0.58A6 + 3.41 71 F U N C T I O N 1 72 Pooled freshwater age d i s c r i m i n a n t models S e v e r a l pooled smolt age/pooled ocean age d i s c r i m i n a n t analyses were c o n s t r u c t e d under the assumption that l a r g e stock d i f f e r e n c e s i n age composition, s i z e s at age, and s c a l e f e a t u r e s ( r e l a t i v e to w i t h i n stock d i f f e r e n c e s ) would d i s t i n g u i s h the f i v e stocks without r e s o r t i n g to smolt age s p e c i f i c models. Because both smolt age 3 and 4 s t e e l h e a d from c e r t a i n stocks tended to grow s i m i l a r i l y (eg small s c a l e zones in the Morice R i v e r ) t h i s suggested that the v a r i o u s freshwater ages (smolt) be pooled to best d e s c r i b e o v e r a l l growth i n each system. Table 14 summarizes the b a s i c d i s c r i m i n a n t a n a l y s i s r e s u l t s f o r a pooled freshwater age/ocean age model. Using Lachenbruch's (1975) holdout procedure the mean c l a s s i f i c a t i o n accuracy for the pooled smolt age/pooled ocean age model was 52.5% (range Zymoetz 35%-Sustut 67%) using s c a l e v a r i a b l e s alone and 61.8% (range Zymoetz 50%-Sustut 72%) using s c a l e v a r i a b l e s i n c o n j u n c t i o n with l e n g t h and weight. F i g u r e 22 summarizes the placement of stock c e n t r o i d s i n d i s c r i m i n a n t space f o r the a l l v a r i a b l e pooled age model. P a i r w i s e comparisons r e v e a l e d that the p a t t e r n s of freshwater s c a l e growth by pooled age were most s i m i l a r f o r the Sustut to Zymoetz, Zymoetz to Babine, Babine to Zymoetz, K i s p i o x to Zymoetz, and M o r i c e - B u l k l e y to Zymoetz st o c k s . 73 F i g u r e 22. D i s c r i m i n a n t f u n c t i o n a n a l y s i s d e s c r i b i n g s c a l e p a t t e r n v a r i a t i o n i n a d u l t s t e e l h e a d of pooled smolt age. The c i r c l e s i n d i c a t e the stock c e n t r o i d s S=Sustut Z=Zymoetz K=Kispiox M=Morice B=Babine *=grand c e n t r o i d , the open c i r c l e s i n d i c a t e the 90% confi d e n c e i n t e r v a l about each c e n t r o i d (from Pimental, 1979), and the l i n e s p o i n t to the next most s i m i l a r stock i n d i s c r i m i n a n t space. The f i r s t two s t a n d a r d i z e d d i s c r i m i n a n t f u n c t i o n s are given below. D1 = 0.45 WT -0.13 A5 -3.97 D1 +14.76 C3 -18.14 C -0.06 D5 -0.06 C5 +0.13 L -2.31 D3 +0.94 A2 +0.13 D6 +0.02 B6 -15.11 B1 +9.44 B3 -7.28 A +0.06 PG -1.81 D2 = 0.30 WT +0.15 A5 +7.85 D1 -17.25 C3 +44.83 C +0.12 D5 +0.11 C5 -0.02 L +5.66 D3 -24.54 A2 -0.13 D6 +0.26 B6 +35.63 B1 -11.13 B3 +18.53 +0.06 PG -4.47 74 + 1. 5 - F U N C T I O N 1 75 D i s c r i m i n a t i o n by sex As both male and female s t e e l h e a d have been shown to grow at s i m i l a r r a t e s i n freshwater (Parker and L a r k i n , 1959) l i t t l e e f f o r t was made to d i s t i n g u i s h between the f i v e Skeena R i v e r s t e e l h e a d s t o c k s on the b a s i s of sex. Any success i n d i f f e r e n t i a t i n g the f i v e s t o c k s on the b a s i s of sex must r e l y on d i f f e r e n c e s i n s i z e at age; f o r t h i s reason, the only d i s c r i m i n a n t models c o n s t r u c t e d by sex were f o r a pooled smolt age/pooled ocean age a n a l y s i s . For such a model, female Skeena River s t e e l h e a d were c o r r e c t l y c l a s s i f i e d to stock of o r i g i n using Lachenbruch's (1975) holdout technique with 65.% (range K i s p i o x 54%-Morice-Bulkley 76%) accuracy ( t a b l e 15) while male Skeena R i v e r s t e e l h e a d were c o r r e c t l y c l a s s i f i e d to stock of o r i g i n with 52.6% accuracy ( t a b l e 16) using the same model. S e v e r a l p o i n t s c o n c e r n i n g a l l of the above models are i n order. F i r s t l y , K i s p i o x and Zymoetz R i v e r s t e e l h e a d had c o n s i s t e n t l y lower c l a s s i f i c a t i o n success i n a l l models than d i d any of the other three s t o c k s . M i s c l a s s i f i c a t i o n s of each to the other were g e n e r a l l y r e s p o n s i b l e f o r lowering the mean c l a s s i f i c a t i o n r e s u l t s of a l l models. Secondly, the v a r i a b l e s chosen f o r stock d i s c r i m i n a t i o n were c o n s i s t e n t l y from the second and t h i r d years of freshwater growth, which suggests that stock d i f f e r e n t i a t i o n i s most prominent w e l l i n t o p a r r stage. T h i r d l y , the range of v a r i a b l e o v e r l a p was h i g h between the s t o c k s , as i n d i c a t e d by the f a i r l y low r a t e s of c l a s s i f i c a t i o n (45%-61%) even though the d i f f e r e n c e s between stock c e n t r o i d s were h i g h l y s i g n i f i c a n t i n each model. F i n a l l y , stock 76 d i s c r i m i n a n c e was g r e a t e s t i n those stocks f a r t h e s t from the ocean (Sustut, Babine, M o r i c e - B u l k l e y ) which suggests the presence of s p e c i f i c growth regimes/and or s e l e c t i o n f a c t o r s f o r growth towards the upper regions of the Skeena River drainage. Not s u r p r i s i n g l y , a r e d u c t i o n i n the number of stocks used i n the analyses r e s u l t e d i n g r e a t e r c l a s s i f i c a t i o n success f o r a l l d i s c r i m i n a n t models. In g e n e r a l , the r e s u l t s of d i s c r i m i n a n t a n a l y s i s support the h y p o t h e s i s of stock d i s c r e t e n e s s i n Skeena Ri v e r s t e e l h e a d . Commercial F i s h e r y Stock Composition The r e s u l t s of s c a l e a n a l y s i s i n d i c a t e d that c l a s s i f i c a t i o n of i n c i d e n t a l l y caught s t e e l h e a d i n the commercial salmon f i s h e r y to stock of o r i g i n was f e a s i b l e . Only one year of commercial data (1984) were a v a i l a b l e f o r c l a s s i f i c a t i o n . Table 17 summarizes the F i s h e r i e s and Oceans s t a t i s t i c a l area 4 s t e e l h e a d c a t c h by week f o r the 1984 commercial salmon f i s h e r y . I n c i d e n t a l catches of s t e e l h e a d i n 1984 were the h i g h e s t on r e c o r d . As shown, peak catches o c c u r r e d with peak e f f o r t (Weeks ending J u l y 21 and 28) d u r i n g the peak of sockeye salmon f i s h i n g . F i g u r e 23 and appendix t a b l e 7 summarize the sample age composition of s t e e l h e a d c o l l e c t e d over the s i x week p e r i o d 9-14 i n 1984. S t e e l h e a d of age 3.2+ and 4.2+ were predominant although s h i f t s i n the other age c l a s s e s were found. A p r o p o r t i o n a l abundance of ocean age .1+ males was found i n 1984, compared to females which were predominantly of ocean age .2+ (Table 18) The mean len g t h s and weights of s t e e l h e a d i n the 77 F i g u r e 23. Age composition s t r u c t u r e by week f o r s t e e l h e a d sampled i n the 1984 commercial f i s h e r y . (compiled from appendix t a b l e 7). WEEK 9 1984 :n=123 WEEK 12 1984 :N -127 - . 1 %y -iX* ^ k v i * ' ^ * »>* ACE CLASS WEEK 10 1984 :N=130 I • • 1 1 1 a . ^ ' a V * v v a * y-i* ^ »i* ACE CLASS WEEK 11 1984 :N=134 a>* a** i>* y i * *>* ^ ACE CLASS 3 0.2 O a-%* a^* y%* y l * y**' k.l* k V ^ AGE CLASS WEEK 13 1984 :N=130 . I I I 1 1 i T,.\* %%* y\* v a * y-s* t.a* k>* tf> AGC CLASS WEEK 14 1984 :N=108 I 1i1 I 1.1 *' ̂n* . a " vb* k%" u>" & aN*V* bV ̂ " b>* <- a* AGE CLASS 79 TABLE 17. Steelhead c a t c h and escapement s t a t i s t i c s through Area 4 f o r the 1984 commercial salmon f i s h e r y . S.W i n d i c a t e s the s t a t i s t i c a l week. (GN=gillnet, SN=seine).Source D.F.O, 1985. Week Ending S.W Gear Catch Days f i s h e d CPUE Escape. H.R 3191 J u l 15 8 290 GN 687 1 2.4 5484 '. 1 25 J u l 21 9 649 GN 7021 4.3 10.8 5750 .619 180 SN 2340 (1.3) 13.0 J u l 28 1 0 591 GN 4362 3 7.4 3324 .735 204 SN 4881 (3) 23.9 Aug 4 1 1 504 GN 4269 3.3) 8.5 4838 .468 Aug 1 1 1 2 297 GN 2854 3 9.6 1 0090 .221 Aug 18 1 3 252 GN 431 9 5 17.0 5433 .443 Aug 25 1 4 80 GN 367 2 4.6 3880 .109 35 SN 105 (1 ) 3.0 Sep 1 1 5 55 GN 167 1 3.0 — 0 TOTAL 31 372 22.9 42989 x=.422 Table 18. Ocean age composition by sex f o r s t e e l h e a d taken i n the 1984 Skeena R i v e r commercial salmon f i shery (assembled from appendix t a b l e 7). Week Ocean age 9 1 0 1 1 1 2 1 3 14 . 1 + %M .278 .221 .333 .464 .285 .222 %F . 1 25 . 1 40 .282 . 1 58 .171 . 106 .2+ %M .544 .573 .560 .375 .457 .587 %F .708 .640 .696 .631 .800 .723 .3 + %M . 1 52 .208 . 1 06 .161 .257 .190 %F . 1 67 .220 .021 .210 .028 . 170 weekly samples g e n e r a l l y i n c r e a s e d through the f i s h e r y (Table 19), which suggests a gen e r a l s h i f t i n s i z e brought about by stock s p e c i f i c run-timing d i f f e r e n c e s . C l a s s i f i c a t i o n of the 1984 commercial f i s h e r y s t e e l h e a d 80 TABLE 19. Mean lengths and weights of s t e e l h e a d sampled in the 1984 commercial salmon f i s h e r y . SW i n d i c a t e s s t a t i s t i c a l week Week SW n Length S Weight S Ending (cm) (kg) J u l 21 9 1 32 69.4 8.2 3.7 1 .3 J u l 28 10 131 72.2 10.5 4.4 1 .9 Aug 4 1 1 127 72.3 9.2 4.4 1 .9 Aug 1 1 1 2 1 22 72.3 8.3 4.4 1 .9 Aug 18 1 3 1 33 74.3 9.5 4.8 1 .9 Aug 25 1 4 108 73.4 8.2 4.7 1 .7 samples to stock of o r i g i n u t i l i z e d four of the twelve d i s c r i m i n a n t a n a l y s i s models p r e v i o u s l y o u l t l i n e d . In order, these were c l a s s i f i c a t i o n of a d u l t s by smolt age 3/pooled ocean age/scale v a r i a b l e s alone (Model A), smolt age 4/pooled ocean age/scale v a r i a b l e s alone (Model B), pooled smolt age/pooled ocean a g e / s c a l e v a r i a b l e s alone (Model C), and model C using s i z e r e l a t e d data i n a d d i t i o n to the s c a l e v a r i a b l e s (Model D). C l a s s i f i c a t i o n of the commercial f i s h e r y samples by s p e c i f i c age c l a s s (eg 3.2+, 4.2+ etc) was not c o n s i d e r e d f e a s i b l e because of the low age c l a s s s p e c i f i c sample s i z e s present in the data base. For a l l a n a l y s e s , the f i v e stocks under study were assumed to occur i n the weekly samples i n p r o p o r t i o n to t h e i r r e l a t i v e o v e r a l l abundance i n the f i s h e r y . Table 20 summarizes the r e s u l t s of c l a s s i f y i n g the 1984 commercial f i s h e r y s t e e l h e a d samples to stock of o r i g i n by the above four models. Temporal d i f f e r e n c e s i n the p o i n t estimates f o r a l l four models were found with some stocks estimated to be present i n l a r g e p r o p o r t i o n s throughout the sample p e r i o d . Morice R i v e r s t e e l h e a d were estimated to be present i n l a r g e Table 20. C l a s s i f i c a t i o n r e s u l t s to stock of o r i g i n by week for s t e e l h e a d sampled from Area 4 i n 1984. Model A: smolt age 3/pooled ocean age/scale v a r i a b l e s alone. Model B: smolt age 4/pooled ocean age/scale v a r i a b l e s alone. Model C: pooled smolt age/pooled ocean age/scale v a r i a b l e s alone. Model D: pooled smolt age/pooled ocean age/scale v a r i a b l e s +length and weight (+/- 95% co n f i d e n c e l i m i t s about the estimated v a r i a n c e s i n b r a c k e t s ) . Week P r o p o r t i o n a l Estimated Stock Composition K i s p i o x Zymoetz Sustut Babine Morice 9 1 0 1 1 12 13 1 4 A 065( . 181 ) 0 ( .253) .454( .091 ) .0261 .092) .454( .200 B 1 49( . 430) . 1 82 ( .440) .298( .097) . 1 17( .086) .254( .232 C 1 06( . 1 50) .038( .251 ) .439( .087) .061 ( .042) . 356( .116 D 0 ( .027) 0 ( .065) .303( .065) .099( .032) .599( .072 A 0 ( .091 ) .057( .251 ) .701 ( .091 ) .081 ( .094) . 1 61 ( . 1 73 B 255( . 424) 0 ( .368) • 395( .121) . 1 1 6( .086) .232( .112 C 091 ( .161) .068( . 1 73) • 496( .094) .0991 -.07 5) . 244 ( . 1 04 D 0 ( .056) 0 ( .072) . 4 1 2 ( .065) . 168( .056) .4 1 9( .072 A 1 05( . 181 ) 0 ( .262) • 376( .092) .223( .108) .294( . 1 66 B 0 ( .775) . 525( .798) .325( .112) 0 < .030) . 1 50( . 1 34 C 1 49( . 200) .087( .141) .425( .091 ) . 1 42 ( .075) . 1 96( . 1 00 D 052( .181) .032( .086) .378( .065) .093( .056) .443( .077 A 0 ( . 1 92) 0 ( .462) .428( .073) .307( .149) .264( .515 B 1 93< .665) .3221 .711) .290( . 1 26) . 1 93( . 1 34) 0 ( .112 C 1 38 ( .092) • 089( .313) • 422( .093) . 1 87 ( . 100) . 1 63 < .094 D 0 ( .072) .262( .086) .336( .072) .287( .072) . 1 1 5( .072 A 1 44 ( . 181 ) 0 ( .274) .490( .092) . 1 63( .079) .202( . 175 B 1 72 ( .660) .241 ( .634) .448( .120) 0 ( . 1 03) . 1 37 ( . 1 42 C 1 72! . 101 ) • 045( .113) . 443 ( .075) .2031 .095) . 1 35( .072 D • 144 1 .065) .071 ( .086) .366( .065) .21 4( .065) .204( .056 A 0 ( . 1 66) . 1 0 1 < .214) .681 ( .092) 0 ( .079) . 2 1 8 ( . 1 75 B 0 < .590) . 2 1 6 ( .634) .486( .117) .054( .103) .243( .141 C 0 ( .101) .083( .094) .639( .081 ) . 1 35( .079) . 1 67( .101 D 0 ( .046) . 1 20 ( .086) .629( .072) .083< .046) . 1 29( .065 82 p r o p o r t i o n s d u r i n g the e a r l y weeks 9 through 10. Babine River s t e e l h e a d were estimated to be present i n l a r g e p r o p o r t i o n s d u r i n g the l a t e r weeks 12 through 14. Both K i s p i o x R i v e r and Zymoetz R i v e r s t e e l h e a d were estimated to be present i n v a r i a b l e p r o p o r t i o n s d u r i n g each week 11 through 13 depending upon the model. In s e v e r a l i n s t a n c e s the p o i n t estimates f o r these stocks were neg a t i v e . However, the c o n f i d e n c e i n t e r v a l s about the e s t i m a t e s i n d i c a t e d that both the K i s p i o x and Zymotez stocks may have been present i n small numbers. For a l l four models, the c o n f i d e n c e l i m i t s were wide and v a r i e d about each p o i n t estimate i n p r o p o r t i o n to the c l a s s i f i c a t i o n success of the o r i g i n a l d i s c r i m i n a n t a n a l y s e s . Confidence i n the p o i n t estimates f o r Babine, Sustut, and M o r i c e - B u l k l e y R i v e r s t e e l h e a d was n o t a b l y g r e a t e r than f o r Zymoetz and K i s p i o x River s t e e l h e a d . The p o i n t estimates i n t a b l e 20 were used to c a l c u l a t e the probable run-timing curves of each s t e e l h e a d stock through the f i s h e r y i n 1984. The d i v e r s e age c l a s s s t r u c t u r e of the 1984 s t e e l h e a d c a t c h suggested that a l l four c l a s s i f i c a t i o n models be used to generate s p e c i f i c run-timing curves. T h i s allowed f o r between model comparison and a more d e t a i l e d run-timing a n a l y s i s . C a l c u l a t i n g the 1984 run-timing curves f i r s t r e q u i r e d data from e x t e r n a l sources. The c a l c u l a t i o n of t o t a l s t e e l h e a d p o p u l a t i o n s i z e d u r i n g each week of the f i s h e r y was c a l c u l a t e d by adding Department of F i s h e r i e s and Oceans weekly s t e e l h e a d c a t c h e s t i m a t e s to the weekly estimated s t e e l h e a d escapement 83 past the t e s t f i s h e r y (summary, next t a b l e ) . The gen e r a l run- S t a t i s t i c a l Week 8 9 1 0 1 1 12 13 14 15 T o t a l Harvest 687 9361 9243 4269 2854 4319 472 167 31372 Index 44.7 26.6 15.4 22.4 46.7 25.1 18.0 - 198.9 Escapement 5484 5750 3324 4838 10090 5433 3880 - 42989 Run S i z e 10662 15111 12567 9107 12944 9752 4352 167 74361 timing curves were c a l c u l a t e d by m u l t i p l y i n g the estimated weekly p o i n t estimates f o r a gi v e n c l a s s i f i c a t i o n model ( t a b l e 20) by the estimated t o t a l s t e e l h e a d p o p u l a t i o n s i z e f o r a given week. Adjustments were made f o r the two smolt age s p e c i f i c c l a s s i f i c a t i o n models (A and B); here, the est i m a t e s of t o t a l weekly run s i z e were set to r e f l e c t the age c l a s s compositions of the weekly samples. In week 9, f o r example, 53.5% of the s t e e l h e a d sample was comprised of a d u l t s of smolt age 3. Thus 53.5% of the t o t a l s t e e l h e a d h a r v e s t + escapement i n week 9 was assumed to be comprised of smolt age 3 a d u l t s . S i m i l a r adjustments were made by week f o r each model. Appendix t a b l e 8 summarizes the r e s u l t s of a p p l y i n g the p r e d i c t e d weekly stock composition estimates from the four c l a s s i f i c a t i o n models ( t a b l e 20) to the estimated weekly harvest + escapement run s i z e s i n the 1984 commercial f i s h e r y . F i g u r e s 24 to 31 summarize the estimated run-timings from appendix t a b l e 8. In g e n e r a l , Morice River and Sustut R i v e r were found to 84 predominate i n the e a r l y weeks of sampling while the other three stocks tended to predominate dur i n g the l a t e r weeks. The "best" run-timing model i s d i f f i c u l t to i d e n t i f y , e s p e c i a l l y c o n s i d e r i n g . the l i m i t a t i o n s imposed by only one year of commercial data and the acknowledgement that 1984 was a unique year f o r s t e e l h e a d r e t u r n s . In a d d i t i o n , the e f f e c t of "other" s t e e l h e a d stocks i n the weekly samples not c o n s i d e r e d i n t h i s study remain unknown. The s p e c i f i c smolt age models ( A and B) reduce the w i t h i n stock s c a l e p a t t e r n v a r i a n c e s but may s u f f e r from reduced sample s i z e s . The pooled smolt age a n a l y s i s (C) l i k e l y i n c r e a s e the w i t h i n stock s c a l e p a t t e r n v a r i a n c e s but has the advantage of u t i l i z i n g much of the data base. The same model with the i n c l u s i o n of s i z e data (D) has the same advantages of (C) p l u s the added b e n e f i t of u t i l i z i n g stock s p e c i f i c s i z e s at age. Model D may s u f f e r , however, i f the f i s h e r y s e l e c t s f o r s i z e or i f s i z e s at age should change a p p r e c i a b l y between years for a given stock. J u v e n i l e A n a l y s i s R i d d e l l and Leggett (1981) p r o v i d e d evidence that morphological v a r i a t i o n s between j u v e n i l e a t l a n t i c salmon from v a r i o u s stocks have an adaptive b a s i s and i s h i g h l y stock s p e c i f i c . The r e s u l t s of comparing Zymoetz R i v e r , K i s p i o x R i v e r , and M o r i c e - B u l k l e y River j u v e n i l e s t e e l h e a d p a r r suggests a s i m i l a r phenomenon in Skeena River s t e e l h e a d . In a u n i v a r i a t e a n a l y s i s of v a r i a n c e s i g n i f i c a n t d i f f e r e n c e s between means for seven of the ten j u v e n i l e m o r p h o l o g i c a l body measurements used 85 F i g u r e 24. P r e d i c t e d r u n - t i m i n g . E s t i m a t e d run-timing composition through the 1984 Skeena R i v e r commercial salmon f i s h e r y f o r a d u l t s t e e l h e a d of smolt age 3/pooled ocean age using s c a l e f e a t u r e s a l o n e . F i g u r e 25. P r e d i c t e d r u n - t i m i n g . Normalized estimated run- timing composition through the 1984 Skeena R i v e r commercial salmon f i s h e r y f o r a d u l t s t e e l h e a d of smolt age 3/pooled ocean age u s i n g s c a l e f e a t u r e s a l o n e . Week Ending UV84) 87 F i g u r e 26. P r e d i c t e d r u n - t i m i n g . Estimated run-timing composition through the 1984 Skeena R i v e r commercial salmon f i s h e r y f o r a d u l t s t e e l h e a d of smolt age 4/pooled ocean age u s i n g s c a l e f e a t u r e s a l o n e . F i g u r e 27. P r e d i c t e d r u n - t i m i n g . Normalized estimated run- t i m i n g composition through the 1984 Skeena River commercial salmon f i s h e r y f o r a d u l t s t e e l h e a d of smolt age 4/pooled ocean age u s i n g s c a l e f e a t u r e s alone. 88 XI00 30- N 23- u m b e r 20- s 10- Key l=Sustut 2 KMori ce 3=L<abine 4«Ki s p i ox 5=Zymoetz 123456!123436!123436112345611234361123456!1234361 I I I I B 7 10 11 1 J u l y 21 August ,4 I I 13 14 August 18 I IS Week Ending (1VB4) X 100 !1234561123436112343611234361123436112343611234361 ! I I I I I ! I B V 10 11 12 13 14 13 J u l y 21 August 4 August 18 Week Ending <1VB4> 89 F i g u r e 28. P r e d i c t e d r u n - t i m i n g . Estimated run-timing composition through the 1984 Skeena River commercial salmon f i s h e r y f o r a d u l t s t e e l h e a d of pooled smolt age/pooled ocean age u s i n g s c a l e f e a t u r e s a l o n e . F i g u r e 29. P r e d i c t e d r u n - t i m i n g . Normalized estimated run- t i m i n g composition through the 1984 Skeena R i v e r commercial salmon f i s h e r y f o r a d u l t s t e e l h e a d of pooled smolt age/ pooled ocean age using s c a l e f e a t u r e s a l o n e . Weols Ending (19131) 91 F i g u r e 30. P r e d i c t e d run-timing. Estimated run-timing composition through the 1984 Skeena River commercial salmon f i s h e r y for a d u l t s t e e l h e a d of pooled smolt age/pooled ocean age using s c a l e f e a t u r e s i n c o n j u n c t i o n with l e n g t h and weight. F i g u r e 31. P r e d i c t e d run-timing. Normalized estimated run- t i m i n g composition through the 1984 Skeena R i v e r commercial salmon f i s h e r y f o r a d u l t s t e e l h e a d of pooled smolt age/pooled ocean age using s c a l e f e a t u r e s i n c o n j u n c t i o n with l e n g t h and weight. Weel; Ending <19B4) Week Ending U9B4) 93 i n t h i s study were found, e s p e c i a l l y f o r caudal peduncle width and caudal peduncle depth (Table 21). Table 21. Adjusted geometric means (+/- one S.D) and the r e s u l t s of one way analyses of v a r i a n c e f o r d i f f e r e n c e s i n body morphology between K i s p i o x , Zymoetz, and Morice- B u l k l e y River s t e e l h e a d p a r r . A l l measurements are i n cm. (* i n d i c a t e s no s i g n i f i c a n t d i f f e r e n c e at the 5% l e v e l of s i g n i f icance) grand mean standard length= 10.29cm (DF=2,88) V a r i a b l e Zymoetz Morice K i s p i o x F P n = 29 n= 29 n = : 30 HL 3. 00 (0. 21 ) 3.07 (0. 13) 3.06 (0. 13) 0. 08 *>0. 05 HD 2. 01 (0. 24) 2.01 (0. 88) 2.11 (0. 12) 3. 1 7 <0. 05 HW 1 . 49 (0. 29) 1.41 (0. 06) 1 .59 (0. 12) 6. 1 2 <0. 05 CD 1 . 1 1 (0. 07) 1 .04 (0. 04) 1.17 (0. 06) 12. 98 <0. 05 CW 0. 48 (0. 07) 0.43 (0. 04) 0.56 (0. 07) 14. 98 <0. 05 BD 2. 84 (0. 18) 2.70 (0. 13) 2.91 (0. 22) 7. 41 <0. 05 BW 1 . 55 (0. 17) 1 .40 (0. 07) 1 .55 (0. 14) 9. 29 <0. 05 PrDL 5. 91 (0. 20) 5.95 (0. 18) 5.92 (0. 14) 0. 42 *>0. 05 PoDL 6. 1 4 (0. 13) 6.10 (0. 19) 6.14 (0. 16) 0. 40 *>0. 05 The r e s u l t s of three stock morphological d i s c r i m i n a n t a n a l y s i s are shown i n f i g u r e 32. M u l t i v a r i a t e a n a l y s i s r e v e a l e d s i g n i f i c a n t d i f f e r e n c e s between the stock c e n t r o i d s (approximate F=8.13 DF= 10 162 P<0.001) and i n a l l p a i r w i s e comparisons between s t o c k s . Four of the o r i g i n a l ten v a r i a b l e s were s e l e c t e d as best d e s c r i b i n g the between stock j u v e n i l e d i f f e r e n c e s ; these were, i n order of entry, head width, caudal peduncle depth, caudal peduncle width, and body width. The f i r s t d i s c r i m i n a n t f u n c t i o n p r i m a r i l y separated K i s p i o x River j u v e n i l e s from the other stocks on the b a s i s of c a u d a l peduncle width and caudal peduncle depth. K i s p i o x j u v e n i l e s had l a r g e mean value s f o r these f e a t u r e s and were g e n e r a l l y more "robust" 94 F i g u r e 32. D i s c r i m i n a n t f u n c t i o n a n a l y s i s d e s c r i b i n g m o r p h o l o g i c a l v a r i a t i o n among j u v e n i l e s t e e l h e a d from the Kispiox,Zymoetz,and M o r i c e - B u l k l e y R i v e r s . Each of the l e t t e r s i n d i c a t e s the stock c e n t r o i d s Z=Zymoetz K=Kispiox M=Morice *=grand c e n t r o i d , the open c i r c l e s i n d i c a t e the 90% co n f i d e n c e i n t e r v a l about each c e n t r o i d (from Pimental, 1979), and the l i n e s p o i n t to the next most s i m i l a r stock i n d i s c r i m i n a n t space. The two s t a n d a r d i z e d d i s c r i m i n a n t f u n c t i o n s are given below. D1 = 1.60HW +8.28CD +8.80CW -1.23BW -8.28 D2 = 0.03HW +0.84CD +1.47CW -1.68BW -14.25 + 1 . 5 - +1. 0 - - 1 . 5 - ! - 2 . 0 - 2 . 0 - 1 . 5 - 1 . 0 - 0 . 5 0 + 0 . 5 +1.0 +1.5 F U N C T I O N 1 96 i n body shape at a given l e n g t h . The second d i s c r i m i n a n t f u n c t i o n separated the Morice River j u v e n i l e s from the other two stocks p r i m a r i l y on the b a s i s of body width. Morice j u v e n i l e s had low mean body widths, and were g e n e r a l l y l e s s "robust" i n o v e r a l l body shape. 61.4% of the j u v e n i l e s from the three stocks were c o r r e c t l y c l a s s i f i e d to stock of o r i g i n u sing Lachenbruch's (1975) holdout c l a s s i f i c a t i o n procedure (range Zymoetz 48.3%- K i s p i o x 70.0%). M i s c l a s s i f i c a t i o n s f o r Zymoetz River j u v e n i l e s were evenly d i v i d e d between the other two st o c k s , a r e s u l t s i m i l a r to the f i n d i n g s of a d u l t c l a s s i f i c a t i o n by s c a l e p a t t e r n f e a t u r e s : These r e s u l t s suggest that the % P r e d i c t e d Stock A c t u a l Stock c o r r e c t K M Z K n = 30 70.0 21 3 6 M n = 29 65.5 4 19 6 Z n = 29 48.3 7 8 1 4 x= 61.4 observable d i f f e r e n c e s i n j u v e n i l e body form f o r Skeena River s t e e l h e a d are q u i t e d i f f e r e n t . While e x t e n s i o n s of such body form a n a l y s i s to the a d u l t s from each stock were not made, i t i s l i k e l y that s i m i l a r shape d i f f e r e n c e s c o u l d be found. Observed a d u l t body p r o p o r t i o n s have been noted to vary widely between the a d u l t s from s e v e r a l Skeena R i v e r s t e e l h e a d stocks (M. Lough, p e r s . Comm. 1985) and may p r o v i d e a d d i t i o n a l i n f o r m a t i o n f o r stock s e p a r a t i o n purposes. 97 DISCUSSION B i o l o g i c a l C o n s i d e r a t i o n s The primary o b j e c t i v e of t h i s study was to t e s t the r a c i a l s e p a r a b i l i t y of Skeena River s t e e l h e a d by s c a l e p a t t e r n a n a l y s i s . S i g n i f i c a n t d i f f e r e n c e s i n s c a l e growth, age composition, s i z e s at age, and j u v e n i l e body morphology e x i s t between s t e e l h e a d from f i v e of the major Skeena R i v e r t r i b u t a r i e s ( M o r i c e - B u l k l e y , K i s p i o x , Zymoetz, Babine, S u s t u t ) . Run-timing d i f f e r e n c e s f o r each stock are a l s o evident i n i n c i d e n t a l catches from the commercial salmon f i s h e r y . T h i s v a r i a b i l i t y confirms the s u b d i v i s i o n of Skeena R i v e r s t e e l h e a d i n t o d i s c r e t e stocks and suggests that stock d i s c r e t e n e s s i s an ada p t i v e p r o p e r t y of the sp e c i e s that has a r i s e n through n a t u r a l s e l e c t i o n . The s c a l e p a t t e r n technique f o r d i f f e r e n t i a t i n g Skeena Ri v e r s t e e l h e a d works b e t t e r f o r some stocks (Sustut, Babine, M o r i c e - B u l k l e y ) than o t h e r s ( K i s p i o x , Zymotez). The success of the technique depends upon the observed l e v e l s of w i t h i n stock compared to between stock v a r i a n c e . T h i s , i n t u r n , depends upon stock d e f i n i t i o n and the v a r i a b l e s chosen f o r a n a l y s i s . The d i v e r s e age c l a s s s t r u c t u r e of Skeena R i v e r s t e e l h e a d makes the c o n s t r u c t i o n of d i s c r i m i n a t i o n models d i f f i c u l t . The use of age s p e c i f i c models, which are most commonly used i n stock d i s c r i m i n a t i o n s t u d i e s , i s q u i t e r e s t r i c t e d f o r t h i s s p e c i e s . The mean c l a s s i f i c a t i o n success f o r the c l a s s i f i c a t i o n models used i n t h i s study was not high (50% to 65%: range Zymoetz 29%- 98 50%- Sustut 55%-75%) but s u b s t a n t i a l l y b e t t e r than random a l l o c a t i o n (20%) and a c c e p t a b l e c o n s i d e r i n g the l a r g e number of st o c k s (5) i n v o l v e d . A c e r t a i n l e v e l of freshwater s c a l e p a t t e r n " s i m i l a r i t y " e x i s t s between a l l Skeena R i v e r s t e e l h e a d . T h i s may r e f l e c t a common response by a l l stocks to s e v e r a l dominant a b i o t i c f e a t u r e s of the Skeena River drainage ( y e a r l y f r e e z e up, peak flows, low temperatures e t c ) . Environmental v a r i a t i o n c o n t r i b u t e s to w i t h i n stock s c a l e p a t t e r n v a r i a b i l i t y i n Skeena R i v e r s t e e l h e a d and determines the success of stock s e p a r a t i o n . Sustut River s t e e l h e a d , which occupy the upper regions of the Skeena R i v e r drainage, are t y p i f i e d by o l d e r ages at s m o l t i n g , wide freshwater s c a l e zones (= l a r g e smolt s i z e s at age), l a r g e a d u l t s i z e s at age, and o l d e r ocean ages at m a t u r i t y . Babine River s t e e l h e a d , which a l s o occupy the upper Skeena R i v e r r e g i o n , are t y p i f i e d by i n t e r m e d i a t e ages at s m o l t i n g , l a r g e freshwater s c a l e zones (= l a r g e smolt s i z e s at age), i n t e r m e d i a t e to l a r g e a d u l t s i z e s at age, and intermediate ocean ages at m a t u r i t y . M o r i c e - B u l k l e y R i v e r s t e e l h e a d , which occupy the " i n l a n d " regions of the Skeena Ri v e r drainage, are t y p i f i e d by o l d e r ages at smolting, small freshwater s c a l e zones (= small smolt s i z e s at age), small a d u l t s i z e s at age, and younger ocean ages at m a t u r i t y . K i s p i o x River s t e e l h e a d occupy the m i d - r i v e r areas of the Skeena River drainage and are t y p i f i e d by o l d e r ages at s m o l t i n g , i n t e r m e d i a t e freshwater s c a l e zones (= intermediate smolt s i z e s at age), notably l a r g e r s i z e s at age, and o l d e r ocean ages at m a t u r i t y . Zymotez R i v e r s t e e l h e a d occupy the lower regions of 99 the Skeena R i v e r drainage and are t y p i f i e d by i n t e r m e d i a t e to o l d e r ages at s m o l t i n g , i n t e r m e d i a t e freshwater s c a l e zones (= intermediate smolt s i z e s at age), i n t e r m e d i a t e to l a r g e s i z e s at age, and i n t e r m e d i a t e ocean ages at m a t u r i t y . J u v e n i l e s from three of the s t o c k s ( K i s p i o x , Zymoetz, M o r i c e - B u l k l e y ) d i s p l a y s i g n i f i c a n t between stock m o r p h o l o g i c a l v a r i a b i l i t y . K i s p i o x River j u v e n i l e s are n o t a b l y more "rob u s t " than the more f u s i f o r m j u v e n i l e s of the M o r i c e - B u l k l e y R i v e r . Stock d i s c r e t e n e s s w i t h i n a s p e c i e s depends upon the l e v e l of i n t e r a c t i o n between e c o l o g i c a l and g e n e t i c processes i n " s t o c h a s t i c " environments (Maclean and Evans, 1981). Var i o u s authors have suggested that s i t e s p e c i f i c homing i n f i s h e s p r o v i d e s the p o t e n t i a l f o r genotypic and phenotypic a d a p t a t i o n to such environments ( L a r k i n 1972, R i c k e r 1972,). Parkinson (1984b) showed t h a t g e n e t i c v a r i a t i o n e x i s t s between s t e e l h e a d p o p u l a t i o n s i n g e o g r a p h i c a l l y a d j a c e n t streams i n B r i t i s h Columbia. He concluded that " t h i s s p e c i e s i s s u b d i v i d e d i n t o a l a r g e number of s e m i - i s o l a t e d p o p u l a t i o n s each having the g e n e t i c p o t e n t i a l t o evolve a d a p t a t i o n s to l o c a l environments". While not a l l o b s e r v a b l e d i f f e r e n c e s between stocks are n e c e s s a r i l y a d a p t i v e , many may have a strong s e l e c t i v e b a s i s . My r e s u l t s suggest t h a t t h i s i s the case f o r the observed p a t t e r n s of v a r i a t i o n i n Skeena R i v e r s t e e l h e a d . Stock d i s c r e t e n e s s by d i s c r i m i n a n t a n a l y s i s depends not only upon s i g n i f i c a n t d i f f e r e n c e s between stock c e n t r o i d s but a l s o upon the l e v e l of i n d i v i d u a l v a r i a n c e about each stock c e n t r o i d ( c e n t r o i d d i s p e r s i o n ) . Sustut, Babine, and M o r i c e - B u l k l e y River 100 e x h i b i t g r e a t e r s e p a r a b i l i t y i n d i s c r i m i n a t i o n models beacuse they e x h i b i t lowered l e v e l s of c e n t r o i d d i s p e r s i o n . Conversely, K i s p i o x and Zymoetz River s t e e l h e a d e x h i b i t lower s e p a r a b i l i t y in d i s c r i m i n a t i o n models because they e x h i b i t i n c r e a s e d l e v e l s of c e n t r o i d d i s p e r s i o n . Assuming that the l e a r n i n g samples used in t h i s study are r e p r e s e n t a t i v e of each stock, then the d i s p e r s i v e homogeneity of some stocks c o u l d represent the presence of dominant s e l e c t i v e f o r c e s . Steelhead from the Sustut and Babine R i v e r s , f o r example, c o u l d e x h i b i t l a r g e freshwater s c a l e zones (= l a r g e smolt s i z e s at age) and l a r g e r a d u l t s i z e s at age because of hydrodynamic s e l e c t i o n f o r l a r g e r s i z e . The upper Skeena R i v e r region i s t u r b u l e n t and l a r g e r body s i z e would enhance both a d u l t and j u v e n i l e upstream/downstream m i g r a t i o n . Hydrodynamic s e l e c t i o n has been suggested by s e v e r a l authors as a p o t e n t i a l l y s t r o n g s e l e c t i v e f o r c e i n salmonids ( S c h a f f e r and E l s o n 1975, Thorpe and M i t c h e l l 1981). S c h a f f e r and E l s o n (1975) concluded that the l a r g e r s i z e s and o l d e r ages of u p r i v e r A t l a n t i c salmon from the Miramichi R i v e r i n New Brunswick are a d a p t a t i o n s to meet the e n e r g e t i c c o s t s of s u s t a i n e d swimming i n g r e a t e r flows d u r i n g long and d i f f i c u l t u p r i v e r m i g r a t i o n . S u s t a i n e d swimming seems to have a strong g e n e t i c component. Tsuyuki and W i l l i s c r o f t (1977) found the swimming endurance of "upstream" F r a s e r River s t e e l h e a d j u v e n i l e s (Thompson R i v e r ) to be s i g n i f i c a n t l y g r e a t e r than the swimming endurance of "downstream" F r a s e r R i v e r j u v e n i l e s ( C h i l l i w a c k R i v e r ) i n t r e a d m i l l type t e s t s . They a t t r i b u t e d the d i f f e r e n c e s to g r e a t e r l e v e l s of the LDH-A a l l e l e 101 in the Thompson River stock which i n c r e a s e s the t h r e s h o l d of muscular f a t i g u e and thus extends s u s t a i n e d swimming a b i l i t y . S t e e l h e a d smolt s i z e s i n c r e a s e with ascending d i s t a n c e upstream i n to the Skeena R i v e r drainage, which confirms my f i n d i n g s by s c a l e p a t t e r n a n a l y s i s . Narver (1969), Whatley (1977), and Whately et a l (1978), reported, that the mean back- c a l c u l a t e d lengths f o r age 3 smolts from the Mo r i c e - B u l k l e y , K i s p i o x , and Babine R i v e r s were 145mm, 163mm, and 187 r e s p e c t i v e l y . The mean b a c k - c a l c u l a t e d lengths f o r age 4 smolts from the same three r i v e r s were 178mm, 195mm, and 203mm r e s p e c t i v e l y . Both g e n e t i c and environmental f a c t o r s c o n t r o l smolt s i z e s at age i n salmonids ( R i c k e r , 1972). Although l a r g e r parents g e n e r a l l y produce l a r g e r eggs and thus l a r g e r f r y , the event u a l s i z e s at smolting depend upon y e a r l y growth r a t e and t h e r e f o r e food a v a i l a b i l i t y . McBride and M a r s h a l l (1983), i n a study of Yukon River chinook salmon stoc k s by s c a l e p a t t e r n s , found that u p r i v e r stocks had l a r g e r a d u l t s i z e s at age yet e x h i b i t e d s m a l l e r freshwater s c a l e zones (= small smolt s i z e s at age) than the lower Yukon r i v e r s t o c k s . They a t t r i b u t e d the smaller u p r i v e r s c a l e zones to lower p r o d u c t i v i t y i n the upper Yukon R i v e r area. T h i s c o n t r a s t s my f i n d i n g s and suggests that food p r o d u c t i v i t y i n the upper Skeena R i v e r i s s u f f i c i e n t l y high enough to produce l a r g e smolts at age. Babine River s t e e l h e a d may a d d i t i o n a l l y b e n e f i t from sockeye salmon enhancement, although l i t t l e i n f o r m a t i o n i s a v a i l a b l e . D i f f e r e n t ' s e l e c t i v e f o r c e s may e x p l a i n the observed f e a t u r e s of s c a l e p a t t e r n and l i f e h i s t o r y v a r i a t i o n i n Morice- 1 02 B u l k l e y River s t e e l h e a d . Although the M o r i c e - B u l k l e y R i v e r i s the l a r g e s t of the f i v e Skeena River t r i b u t a r i e s i t s flows are r a t h e r uniform over long, low g r a d i e n t d i s t a n c e s . Whately et a l . (1978) a t t r i b u t e d the small s i z e s and o l d e r ages of Morice- B u l k l e y R i v e r s t e e l h e a d smolts to low instream p r o d u c t i v i t y . The smaller a d u l t s i z e s at age and younger ages at m a t u r i t y of M o r i c e - B u l k l e y River s t e e l h e a d suggests that strong e c o l o g i c a l s e l e c t i o n f o r r a p i d a d u l t maturation may e x i s t . Rapid a d u l t maturation would ensure maximal f r y seeding (and parr to smolt production) i n l e s s p r o d u c t i v e environments on a y e a r l y b a s i s by minimizing the time between year c l a s s spawnings. Older ages at m a t u r i t y would extend the time between year c l a s s spawnings and thus i n c r e a s e the b i o l o g i c a l r i s k of poor parr p r o d u c t i o n i n l e s s f a v o r a b l e years. The e a r l y p r e d i c t e d run-timing of Morice- B u l k l e y River s t e e l h e a d through the 1984 commercial f i s h e r y supports the n o t i o n of " r a p i d maturation" i n t h i s stock; however, e a r l y run-timing i s probably b e t t e r r e l a t e d to the long d i s t a n c e s i n l a n d M o r i c e - B u l k l e y River s t e e l h e a d must t r a v e l . Sustut River s t e e l h e a d were a l s o p r e d i c t e d to pass through the 1984 commercial f i s h e r y q u i t e e a r l y , which makes such a hypothesis t e n a b l e . It i s p o s s i b l e t h a t small s i z e s at age and young ages at f i r s t spawning i n M o r i c e - B u l k l e y River s t e e l h e a d r e p r e s e n t s a cumulative g e n e t i c e f f e c t from commercial f i s h i n g . R i c k e r (1981) documents the d e c r e a s i n g s i z e s at age and ages at m a t u r i t y f o r many P a c i f i c salmon stocks and a t t r i b u t e s the t r e n d to s i z e s e l e c t i o n f o r o l d e r and thus more mature i n d i v i d u a l s i n 103 commercial f i s h e r i e s . However, the s i z e composition of Morice- B u l k l e y River s t e e l h e a d has remained r a t h e r constant over time, as shown by the homogenous l e n g t h f r e q u e n c i e s of s t e e l h e a d p a s s i n g Moricetown r a p i d s from 1961-1967 (Harding and Buxton, 1971) and from the 1976-1977 data used i n t h i s study. While not c o n c l u s i v e , t h i s evidence suggests that commercial f i s h e r y e f f e c t s may be l e s s important than e c o l o g i c a l f o r c e s i n determining the s i z e s at age and ages at f i r s t spawning of M o r i c e - B u l k l e y R i v e r s t e e l h e a d . Steelhead from the K i s p i o x and Zymoetz R i v e r s show a high degree of freshwater s c a l e p a t t e r n o v e r l a p . T h i s suggests that environmental growth regimes i n the two sytems are somewhat s i m i l a r . Both stocks i n h a b i t " c o a s t a l " type r i v e r s although the Zymoetz River i s c o n s i d e r a b l y l a r g e r and may e x h i b i t a wider range of environments. Stock s e p a r a t i o n by d i s c r i m i n a n t a n a l y s i s i n c r e a s e s between the two o n l y when a d u l t s i z e s at age ( l e n g t h and weight) are i n t r o d u c e d , which, being s u b s t a n t i a l l y g r e a t e r i n the K i s p i o x stock, i m p l i e s e i t h e r g e n e t i c d i f f e r e n c e s i n ocean growth r a t e s and/or d i f f e r e n c e s i n ocean m i g r a t i o n and f e e d i n g p a t t e r n s . T h i s n a t u r a l l y leads to the p o t e n t i a l f o r d i s c r i m i n a t i n g the stocks on the b a s i s of s c a l e p a t t e r n ocean growth. However, f i r s t year ocean growth d i f f e r e n c e s between the two were not that pronounced even f o r the age s p e c i f i c models developed i n t h i s study (3.2+, 4.2+). S c a l e growth a f t e r the f i r s t ocean year was not examined and c o u l d l e a d to d i f f e r e n c e s f o r s e p a r a t i n g the two s t o c k s . No d e f i n i t i v e reasons fo r the s i m i l a r i t y of freshwater s c a l e p a t t e r n s i n 104 K i s p i o x R i v e r and Zymoetz R i v e r s t e e l h e a d seem obvious. The K i s p i o x R i v e r , being g l a c i a l i n i t s headwaters, i s fed by many la k e s , bogs, and creeks s i t u a t e d i n a s e r i e s of low h i l l s and benches which pr o v i d e moderate flows and h i g h water q u a l i t y (Whately, 1977). The Zymoetz R i v e r has a somewhat s i m i l a r morphology except on a l a r g e r s c a l e . I t should be noted that s t e e l h e a d from the Zymoetz River are p r o x i m a l l y c l o s e to the m u l t i v a r i a t e grand c e n t r o i d f o r a l l stocks which thus supports the n o t i o n of environmental h e t e r o g e n e i t y f o r t h i s system. The r e s u l t s of j u v e n i l e a n a l y s i s bear f u r t h e r comment. K i s p i o x R i v e r j u v e n i l e s are q u i t e "robust", e x h i b i t i n g deep heads, deep bodies, and " t h i c k " c a u d a l peduncles. In c o n t r a s t , M o r i c e - B u l k l e y R i v e r j u v e n i l e s are q u i t e " f u s i f o r m " , e x h i b i t i n g smaller heads, s l e n d e r b o d i e s , and " t h i n n e r " caudal peduncles. Zymoetz r i v e r j u v e n i l e s demonstrate a broad c r o s s - s e c t i o n of both body ty p e s . Body shape i n salmonids, e s p e c i a l l y j u v e n i l e s , has been shown to have a g e n e t i c b a s i s and may be h i g h l y adaptive ( R i d d e l l et a l . , 1981). Stream h a b i t a t ( s u b s t r a t e , flows, space, p o o l r r i f f l e r a t i o s , cover, e t c ) i s extremely important f o r j u v e n i l e salmonid b i o l o g y (Northcote, 1969). In g e n e r a l , those streams with higher flow v e l o c i t y and longer m i g r a t i o n routes may s e l e c t f o r a more f u s i f o r m body shape in the j u v e n i l e s to reduce drag and maximize s u s t a i n e d swimming a b i l i t y ( T a y l o r , 1984). R e l a t i n g to t h i s study, the c o n c e n t r a t i o n of o l d e r s t e e l h e a d p a r r i n the M o r i c e - B u l k l e y River i s h e a v i e s t i n the lower reaches (Tredger, 1984), appa r e n t l y because of l i m i t e d upstream p r o d u c t i v e c a p a c i t y . 105 Here, the parr are s u b j e c t to higher flow v e l o c i t i e s and l e s s m i c r o h a b i t a t "refuges" compared to K i s p i o x R i v e r parr which rear throughout the drainage. K i s p i o x River j u v e n i l e s e x h i b i t the t y p i c a l " c o a s t a l " ( T a y l o r , 1984) body type where hydrodynamic s e l e c t i o n f o r s u s t a i n e d swimming a b i l t y may be l e s s important. Zymoetz River j u v e n i l e s e x h i b i t both body types which supports the n o t i o n of growth in a wide range of h a b i t a t s . Body form d i f f e r e n c e s may extend to the a d u l t s from each Skeena River stock and c o u l d provide a d d i t i o n a l i n f o r m a t i o n f o r stock s e p a r a t i o n purposes. T h e o r e t i c a l C o n s i d e r a t i o n s E r r o r s i n data i n t e r p r e t a t i o n , assumed r e p r e s e n t a t i v e n e s s of the data, and the assumptions of d i s c r i m i n a n t a n a l y s i s are a l l of concern f o r the present study. F i r s t l y , data i n t e r p r e t a t i o n was based on e s t a b l i s h e d methods. Any m i s i n t e r p r e t a t i o n by the author i s homogenous a c r o s s a l l samples used f o r d i s c r i m i n a t i o n and c l a s s i f i c a t i o n i n t h i s study. Secondly, r e p r e s e n t a t i v e n e s s of the data was l i m i t e d by the a v a i l a b i l i t y of l e a r n i n g s c a l e samples. I d e a l l y , d i s c r i m i n a t i o n should be achieved u s i n g f i s h from the same brood year and of the same age from each stock. T h i s would l i m i t any v a r i a b i l i t y a t t r i b u t a b l e to d i f f e r e n c e s i n age and y e a r l y d i f f e r e n c e s i n growth. However, the d i v e r s e age c l a s s s t r u c t u r e of Skeena River s t e e l h e a d precludes any simple age s p e c i f i c d i s c r i m i n a t i o n approach except for the dominant age c l a s s e s (3.2+, 4.2+). Even then, I would question the u t i l i t y of age s p e c i f i c analyses f o r 1 06 Skeena R i v e r s t e e l h e a d . The p a t t e r n s of freshwater s c a l e growth found i n t h i s study appear to i n d i c a t e t h a t steelhead of d i f f e r e n t t o t a l ages but of the same smolt age from each stock have s i m i l a r p a t t e r n s of freshwater s c a l e growth. T h i s argues a g a i n s t the n e c e s s i t y of age s p e c i f i c models. However, the p o t e n t i a l e f f e c t s of d i f f e r e n t i a l freshwater s c a l e growth by brood year on the r e s u l t s of t h i s study are harder to q u a n t i f y . Based on l i m i t e d evidence, i t appears t h a t freshwater s c a l e growth i s r e l a t i v e l y s t a b l e between brood years fo r a given stock. S i g n i f i c a n t d i f f e r e n c e s i n s c a l e growth between y e a r l y samples (and thus brood years) f o r s e v e r a l of the stocks used i n t h i s study were not e v i d e n t . T h i s supports the use of d i f f e r e n t brood years fo r c o n s t r u c t i n g stock s p e c i f i c l e a r n i n g samples. Furth e r c l a r i f i c a t i o n of t h i s p o i n t i s needed, e s p e c i a l l y with regard to d i f f e r e n t i a l d e n s i t y e f f e c t s on s c a l e growth. T h i r d l y , i t i s p o s s i b l e t h a t v i o l a t i o n of the assumptions necessary f o r l i n e a r d i s c r i m i n a n t f u n c t i o n a n a l y s i s c o u l d a f f e c t the d i s c r i m i n a t i o n and c l a s s i f i c a t i o n models developed i n the study. Each "stock" should be d i s c r e t e and d e f i n a b l e . T h i s requirement appears to have been met, a l t h o u g h substock s t r u c t u r e and i t s e f f e c t on d i s c r i m i n a t i o n success was not i n v e s t i g a t e d . S t r a y i n g between stocks i s assumed to be minimal, which should maintain group i d e n t i t y f o r d i s c r i m i n a t i o n purposes. The assumption of m u l t i v a r i a t e n o r m a l i t y f o r the d i s c r i m i n a t i n g v a r i a b l e s used i n the study c o u l d have been v i o l a t e d because t e s t s f o r m u l t i v a r i a t e n o r m a l i t y were 1 07 u n a v a i l a b l e . M u l t i v a r i a t e n o r m a l i t y i s e s p e c i a l l y important f o r l i n e a r d i s c r i m i n a n t a n a l y s i s because of the nature of the d e c i s i o n s u r f a c e s used to separate groups. In l i n e a r a n a l y s i s , these s u r f a c e s are a c t u a l l y l i n e a r c l a s s i f i c a t i o n boundaries that best separate e l l i p s o i d a l ( m u l t i v a r i a t e normal) hyperspheres. I f the m u l t i v a r i a t e d e n s i t y d i s t r i b u t i o n s are not normal, then the d i s t r i b u t i o n contours of each group can randomly " o v e r l a p " the d e c i s i o n s u r f a c e and r e s u l t i n reduced c l a s s i f i c a t i o n success. I r e l i e d on u n i v a r i a t e frequency comparisons f o r each stock to estimate m u l t i v a r i a t e data n o r m a l i t y . T h i s does not guarantee t h a t the d i s t r i b u t i o n s are m u l t i v a r i a t e normal (Pimental, 1979). The assumption of homogenous v a r i a n c e - c o v a r i a n c e s t r u c t u r e between stock s was not r i g o r o u s l y t e s t e d i n t h i s study. Stock s p e c i f i c v a r i a n c e - c o v a r i a n c e m a t r i c e s d e s c r i b e the p a t t e r n s of spread and l i n e a r v a r i a b l e a s s o c i a t i o n w i t h i n groups on a m u l t i v a r i a t e b a s i s ( i e . V a r i a b l e s should show the same p a t t e r n s of a s s o c i a t i o n f o r each s t o c k ) . The e f f e c t s of d i s p e r s i v e i n e q u a l i t y on c a n o n i c a l axes and d i s c r i m i n a t i o n f u n c t i o n s i s not w e l l known (Pimental, 1979). G i l b e r t (1969) notes that l i n e a r d i s c r i m i n a n t a n a l y s i s i s s t i l l v a l i d f o r c l a s s i f i c a t i o n purposes even when the hypothesis of d i s p e r s i v e e q u a l i t y i s r e j e c t e d . A p p a r e n t l y , i n e q u a l i t y of d i s p e r s i o n s has no r e a l e f f e c t on m u l t i v a r i a t e a n a l y s i s of v a r i a n c e type I or type II e r r o r s i f the sample s i z e s are l a r g e and of equal s i z e (Pimental, 1979). In other words, the t e s t of c e n t r o i d e q u a l i t y by MANOVA i s powerful enough to r e s u l t i n r e j e c t i o n even when s l i g h t 108 departures from d i s p e r s i v e e q u a l i t y are apparent. I t i s p o s s i b l e that the use of non-parametric d i s c r i m i n a n t analyses (eg q u a d r a t i c a n a l y s i s , Cook and Lord, 1978), which make no assumptions r e g a r d i n g u n d e r l y i n g d e n s i t y d i s t r i b u t i o n s or d i s p e r s i v e r e l a t i o n s h i p s w i t h i n and between groups, c o u l d have pr o v i d e d b e t t e r r e s u l t s . However, q u a d r a t i c a n a l y s i s i s p r i m a r i l y u s e f u l when there are s i g n i f i c a n t d i f f e r e n c e s between the v a r i a n c e s of the v a r i a b l e s used i n the a n a l y s i s . T h i s d i d not seem to be the case f o r t h i s study. The c h o i c e of which v a r i a b l e s best separate the stocks i n t h i s study c o u l d a l s o be subject to e r r o r . In common with the m a j o r i t y of d i s c r i m i n a n t a n a l y s i s s t u d i e s using l a r g e v a r i a b l e systems, I chose to use stepwise v a r i a b l e s e l e c t i o n procedures. Johnson and Wichern (1982) note the problems of using stepwise v a r i a b l e s e l e c t i o n techniques f o r c o n s t r u c t i n g d i s c r i m i n a n t f u n c t i o n s . There i s no guarantee that the subset s e l e c t e d i s "best". In f a c t , although d i s c r i m i n a n t a n a l y s i s r e l i e s on v a r i a b l e s t hat show some degree of i n t e r c o r r e l a t i o n (Pimental, 1979), l a r g e i n t e r c o r r e l a t i o n s between l i n e a r combinations of v a r i a b l e s w i l l magnify the "the problems a s s o c i a t e d with v a r i a b l e s e l e c t i o n procedures" (Johnson and Wichern, 1982). T h i s aspect was not f u l l y i n v e s t i g a t e d . Commercial F i s h e r y C o n s i d e r a t i o n s The second o b j e c t i v e of t h i s study was to assess the p o t e n t i a l of s c a l e p a t t e r n a n a l y s i s f o r i d e n t i f y i n g Skeena R i v e r s t e e l h e a d s t o c k s caught i n the commercial salmon f i s h e r y . As 109 p r e v i o u s l y noted, a l l f i v e major stocks were separable i n the 1984 f i s h e r y w i t h i n v a r y i n g bounds of c o n f i d e n c e . Although age composition d i f f e r e n c e s between the stocks are pronounced i n the l e a r n i n g samples, no d i s t i n c t stock s p e c i f i c p a t t e r n s of age composition through the commercial f i s h e r y was e v i d e n t i n 1984. Th i s stems from the composite run-timing nature of Skeena River s t e e l h e a d . Although based on l i m i t e d evidence, i t may not be p o s s i b l e to use age composition data f o r c a t c h a l l o c a t i o n . In g e n e r a l , the four-model f i v e stock c l a s s i f i c a t i o n a n a l y s es f o r 1984 p r e d i c t e d the e a r l y run-timing and numerical dominance of Sustut R i v e r and M o r i c e - B u l k l e y R i v e r s t e e l h e a d through the f i s h e r y . The same models p r e d i c t e d the l a t e r run- timings and l e s s abundant dominance of Babine, Zymoetz, and K i s p i o x R i v e r s t e e l h e a d through the f i s h e r y . The e x c e p t i o n was fo r the smolt age 4/pooled ocean age/scale v a r i a b l e only a n a l y s i s . Here, both Babine and K i s p i o x stocks were p r e d i c t e d to be prominent dur i n g the e a r l y p a r t s of the f i s h e r y . T h i s may r e f l e c t d i f f e r e n t i a l time at r e t u r n f o r s t e e l h e a d of d i f f e r e n t smolt ages or e r r o r i n the a n a l y s i s because of reduced sample s i z e s . The same trend was not seen i n the pooled smolt age c l a s s i f i c a t i o n a n a l y s i s . F u r t h e r study i s r e q u i r e d to c l a r i f y t h i s p o i n t . The weekly p o i n t e s t i m a t e s of stock abundance i n 1984 are s u f f i c i e n t l y v a r i a b l e enough t o r e s u l t i n c o n s i d e r a b l e temporal f l u c t u a t i o n f o r the ru n - t i m i n g e s t i m a t e s . The assumption of normalized run-timing may or may not be p r a c t i c a l because of t h i s . However, based on the long term p a t t e r n s (normal) of 1 10 s t e e l h e a d r e t u r n and escapement to the Skeena R i v e r , I b e l i e v e that n o r m a l i z e d run-timing i s a v a l i d assumption f o r t h i s study. A l l four c l a s s i f i c a t i o n a n a l y ses f o r 1984 r e s u l t e d i n s e v e r a l n e g a t i v e p o i n t estimate values f o r some of the stoc k s (eg Zymoetz, K i s p i o x , t a b l e 20). However, the 90% con f i d e n c e i n t e r v a l s a s s o c i a t e d with these estimates u s u a l l y i n c l u d e d an upper p o s i t i v e l i m i t . I t seems u n l i k e l y that those stocks with n e g a t i v e p o i n t estimates were not a c t u a l l y present i n the f i s h e r y d u r i n g the sample p e r i o d . Rather, the negative e s t i m a t e s r e f l e c t the d i f f i c u l t y i n e s t i m a t i n g c o n t r i b u t i o n r a t e s f o r s t o c k s i n low abundance by s c a l e p a t t e r n a n a l y s i s when l e a r n i n g sample c l a s s i f i c a t i o n success i s low. S c a l e p a t t e r n a n a l y s i s p r e d i c t e d the l a r g e s t component of the 1984 f i s h e r y to be the Sustut R i v e r stock. T h i s i s somewhat s u r p r i s i n g as p o p u l a t i o n l e v e l s i n t h i s sytem are not b e l i e v e d to be h i g h . T h i s e i t h e r suggests that p r e v i o u s p o p u l a t i o n e s t i m a t e s are i n e r r o r or that other stocks with s c a l e p a t t e r n s s i m i l a r to the Sustut R i v e r stock but not c o n s i d e r e d f o r a n a l y s i s were present i n the f i s h e r y samples. Both p o s s i b i l i t i e s need i n v e s t i g a t i o n . Steelhead p r o d u c t i o n i n the upper Skeena River region i s not w e l l d e f i n e d . In a d d i t i o n , s e v e r a l downstream " s t o c k s " ( L a k e l s e , Kitsumkalum, Suskwa, Kitwanga) c o u l d a l s o have s c a l e p a t t e r n s s i m i l a r to the Sustut system. M o d i f i c a t i o n of the method may be necessary as f u r t h e r i n f o r m a t i o n becomes a v a i l a b l e . A l though s i z e ( l e n g t h and weight) i s a good stock d i s c r i m i n a t o r f o r Skeena R i v e r s t e e l h e a d , i t s use f o r commercial 111 f i s h e r y c l a s s i f i c a t i o n must be done with c a u t i o n . Any s i z e s e l e c t i v i t y by the commercial f i s h e r y w i l l b i a s the estimates of stock abundance i n the f i s h e r y samples used f o r c l a s s i f i c a t i o n purposes. Scale p a t t e r n a n a l y s i s i t s e l f i s not a f f e c t e d by p o t e n t i a l s i z e s e l e c t i v i t y as s c a l e f e a t u r e s (freshwater) i n Skeena R i v e r s t e e l h e a d appear to be independent of eventual a d u l t age (and thus s i z e ) . A l l four c l a s s i f i c a t i o n models developed i n t h i s study should be used to c l a s s i f y commercial f i s h e r y s t e e l h e a d i n t e r c e p t i o n s u n t i l v a r i a b i l i t y i n the technique i s c l e a r l y e s t a b l i s h e d . Stock s p e c i f i c run-timing has been p r e v i o u s l y noted f o r both Skeena River sockeye and pink salmon (Aro and McDonald 1968, L a r k i n and McDonald 1968, McDonald 1981). Temporal s h i f t s i n stock s p e c i f i c run-timing f o r these s p e c i e s appears to be s l i g h t between years ( L a r k i n and McDonald, 1968) although some v a r i a b i l i t y i s present. For Skeena R i v e r s t e e l h e a d the e f f e c t s Of d i f f e r e n t i a l brood year success and stock abundance on the a p p l i c a b i l i t y of the s c a l e p a t t e r n technique i s of concern. Stock abundance w i l l f l u c t u a t e between years a c c o r d i n g to the numerical r e t u r n s by brood year to each stock f o r each c o n t r i b u t i n g age c l a s s ; i f the r e t u r n s to a given stock happen to be low (high) i n a given year because of a s e r i e s of poor (good) brood year successes, then fewer (more) f i s h from that stock w i l l be present i n the f i s h e r y and a v a i l a b l e f o r c l a s s i f i c a t i o n . Assuming that each stock i s sampled a c c o r d i n g to i t s p r o p o r t i o n a l abundance and that the sampling design i s adequate, then the technique of s c a l e p a t t e r n s should respond to 1 1 2 such f l u c t u a t i o n s . However, at the present stage of development, the technique cannot d i s t i n g u i s h between a c t u a l s h i f t s i n the p r e d i c t e d run-timing curve and/or simply changing abundance. For example, stock A which comprises 50% of the c a t c h i n week 1 i n year 1 may have a p r e d i c t e d abundance i n week 1 of year 2 of 20%. E i t h e r l e s s f i s h from that stock are a v a i l a b l e f o r capture i n year 2 ( d i f f e r e n t abundance, same run- timing) or the run-timing curve has s h i f t e d e a r l i e r or l a t e r (same abundance, d i f f e r e n t r u n - t i m i n g ) , or both. For the most p a r t , I have assumed the former although f u r t h e r i n v e s t i g a t i o n i s c l e a r l y r e q u i r e d . Another aspect a f f e c t i n g the u t i l i t y of the s c a l e p a t t e r n technique i s i t s o v e r a l l accuracy. D i s c r i m i n a t i o n success i s v a r i a b l e enough to r e s u l t i n wide confidence l i m i t s ,for some of the p o i n t estimates of commercial f i s h e r y stock c o n t r i b u t i o n (eg Zymotez). T h i s r e f l e c t s the l e v e l of s c a l e p a t t e r n o v e r l a p between the stocks and cannot be mod i f i e d . To i n c r e a s e stock d i s c r i m i n a n c e and c l a s s i f i c a t i o n success, the p o s s i b i l i t y of u t i l i z i n g other m u l t i v a r i a t e f e a t u r e s i n c o n j u n c t i o n with s c a l e p a t t e r n s should be pursued." These include body morphology, m e r i s t i c s , p a r a s i t e s , gene f r e q u e n c i e s e t c . The i n c l u s i o n of such c h a r a c t e r systems must be weighed ag a i n s t t h e i r i n c r e a s e d d i f f i c u l t y of c o l l e c t i o n ; however, once e s t a b l i s h e d , they c o u l d p r o v i d e v a l u a b l e i n f o r m a t i o n f o r stock s e p a r a t i o n purposes. F o u r n i e r et a l . (1983) have used such an approach f o r d i s t i n g u i s h i n g chum salmon stoc k s with f a v o r a b l e r e s u l t s . 1 13 Gear S e l e c t i v i t y R i c k e r (1981) notes that the mode of s e l e c t i o n on i n c i d e n t a l salmonid s p e c i e s caught i n net f i s h e r i e s f o r sockeye salmon depends upon t h e i r s i z e . For example, chinook salmon taken i n c i d e n t a l l y are o f t e n s m a l l e r than t h e i r average s i z e i n the run at that time while pink salmon taken i n c i d e n t a l l y tend to be l a r g e r than t h e i r average s i z e in the run at that time. T h i s r e s u l t s i n c o n s i d e r a b l e s i z e d i f f e r e n c e s between those f i s h , caught and those f i s h which escape the commercial f i s h e r y to spawn. Over time, s t r o n g genetic s e l e c t i o n by s i z e i s p o s s i b l e . The degree of s i m i l a r response f o r Skeena River s t e e l h e a d i s d i f f i c u l t to e s t a b l i s h although some s e l e c t i o n f o r s m a l l e r s i z e s and younger ages at m a t u r i t y no doubt e x i s t s . G e n e r a l l y , the g i l l n e t f i s h e r y s e l e c t s f o r l a r g e r four year o l d male sockeye salmon (2-3 kg) and l a r g e r female f i v e year o l d sockeye salmon (3 kg) (L. Janz, p e r s . Comm., 1985). Any s e l e c t i v e e f f e c t s on s t e e l h e a d by s i z e may be somewhat reduced by the extreme l e v e l s of f i s h i n g e f f o r t i n the Skeena River e s t u a r y . Oguss and Andrews (1977) found that mesh s i z e s have no s i g n i f i c a n t e f f e c t on the numerical s i z e of the i n c i d e n t a l Skeena R i v e r s t e e l h e a d c a t c h . Although b e h a v i o r a l d i f f e r e n c e s between the stocks may change t h e i r s u s c e p t a b i l i t y to an unknown extent (depth of swimmimng, p r o x i m i t y to shore etc.) s t e e l h e a d caught i n the 1984 f i s h e r y were more o f t e n " t a n g l e d " than g i l l e d , r e g a r d l e s s of s i z e ( i n t e r v i e w d a t a ) . In a d d i t i o n , the dense nature of g i l l n e t t i n g may reduce the chances of any given s t e e l h e a d s u c c e s s f u l l y m i g r a t i n g past the f i s h e r y . 1 1 4 T h i s argues a g a i n s t any s p e c i f i c s i z e s e l e c t i v e e f f e c t s of commercial f i s h i n g . Reductions i n o v e r a l l stock s p e c i f i c esapement may be more important. A p p l i c a t i o n s to Steelhead Management A major management o b j e c t i v e f o r Skeena R i v e r s t e e l h e a d i s to minimize the p o t e n t i a l impacts of stock s p e c i f i c i n c i d e n t a l h a r v e s t i n g d u r i n g the commercial salmon f i s h e r y . My r e s u l t s p r o v i d e a method f o r i d e n t i f y i n g which stocks are present i n the f i s h e r y and thus p r o v i d e the p o t e n t i a l f o r s t r u c t u r i n g stock s p e c i f i c management o b j e c t i v e s . However, the f i s h e r y i s extremely dynamic and i s r e g u l a t e d by complex socio-economic f a c t o r s . Short of r e s o r t i n g to a wier system or d r a s t i c a l l y r e ducing the s i z e of the commercial f l e e t , the problem of i n c i d e n t a l s t e e l h e a d catches i n the f i s h e r y i s not e a s i l y s o l v e d . The p r i n c i p l e concern f o r s t e e l h e a d i s adverse h a r v e s t r a t e pressured Mean weekly percent harvest r a t e s on s t e e l h e a d appear to i n c r e a s e d r a m a t i c a l l y i f continuous f i s h i n g i s extended beyond three days per week (BCF Branch, unpublished data, 1983). In a d d i t i o n , the mean percent weekly harvest r a t e f o r sockeye i s higher than that f o r s t e e l h e a d i n a three day per week or l e s s f i s h e r y while i t becomes lower i n a four day per week or more f i s h e r y . Presumably, t h i s r e l a t e s to the f a c t t h a t s t e e l h e a d move i n t o the f i s h e r y area d a i l y whereas sockeye salmon tend to pool and can be harvested q u i t e q u i c k l y . The problem of i n c r e a s i n g weekly ha r v e s t r a t e p r e s s u r e on s t e e l h e a d i s most prominent d u r i n g peak sockeye salmon run-timing where 1 1 5 f i s h i n g may a c t u a l l y c o n t i n u e f o r f i v e days per week (eg Monday, Tuesday, Wednesday, Saturday, Sunday). What i s the best commercial f i s h i n g s t r a t e g y that would reduce commercial h a r v e s t s on steelhead? F i r s t l y , my r e s u l t s suggest that peak stock s p e c i f i c run- t i m i n g , while composite, i s somewhat compressed w i t h i n a short p e r i o d of time. How " s h o r t " w i l l depend upon the estimates of v a r i a b i l i t y obtained f o r f u t u r e a n a l y s e s . Any management a l t e r n a t i v e s f o r reducing i n c i d e n t a l catches should focus on maximizing escapement d u r i n g run-timing peaks. Three techniques are apparent. The f i r s t i s to stop a l l f i s h i n g d u r i n g the estimated peak run-timings f o r each s t o c k . L o g i s t i c a l l y , such an approach i s not f e a s i b l e . The second i s to make use of more f i s h e r y c l o s u r e s or "windows" on a weekly b a s i s . T h i s would ensure t h a t p o r t i o n s of run-timing peaks escape the f i s h e r y r a t h e r than r i s k e n t i r e cohort removal d u r i n g long f i s h e r y openings. P r e s e n t l y , f i s h i n g occurs 24 hours a day d u r i n g any given continuous opening (two, t h r e e , four days e t c ) . As an example of window use, three or four days of f i s h i n g i n t e r s p e r s e d by two days of c l o s u r e (windows) may be more b e n e f i c i a l to s t e e l h e a d than three or four days of continuous f i s h i n g f o l l o w e d by two days of c l o s u r e (the present p r a c t i c e ) . T h i s assumes, of course, t h a t s t e e l h e a d do i n f a c t migrate through the f i s h e r y area q u i t e q u i c k l y . An i n t e n s i v e tagging study of s t e e l h e a d through the commercial f i s h e r y area would h e l p to c l a r i f y the l a t t e r p o i n t . One p o t e n t i a l problem of i n t e r s p e r s e d windows i s 1 1 6 p o t e n t i a l l y apparent dur i n g the presence of the seine f l e e t , which i s r e s t r i c t e d to the outer regions of the f i s h e r y a r ea. During p e r i o d s of intense s e i n e r a c t i v i t y (peak sockeye salmon abundance) s e i n e r s remove st e e l h e a d that normally would be caught a few days l a t e r at the r i v e r mouth had the s e i n e r s not been present. Window c l o s u r e s d u r i n g such p e r i o d s may do more harm than good by a l l o w i n g f i s h i n g pressure time to b u i l d ; those s t e e l h e a d managing to pass the outer seine f l e e t n e g o t i a t e the f i s h i n g area d u r i n g the c l o s u r e and are taken anyway by g i l l n e t t e r s when f i s h i n g reopens a few days l a t e r . Under such circumstances, o v e r a l l s t e e l h e a d escapement may be g r e a t e r using a normal p a t t e r n of longer f i s h e r y openings. The t h i r d technique i s to simply reduce f i s h i n g e f f o r t from 24 to 12 hours per day. T h i s would c r e a t e " n i g h t l y " windows and would not r e s t r i c t the movements of the commercial salmon f l e e t to the same extent as f u l l d a i l y c l o s u r e s . Thus, sockeye f i s h i n g c o u l d occur f o r four or f i v e days c o n t i n u o u s l y while peaks of s t e e l h e a d stock abundance would s t i l l be a b l e to escape through the f i s h e r y (assuming n i g h t l y movements do, i n f a c t , o c c u r ) . In summary, I b e l i e v e ' that the technique of s c a l e p a t t e r n s i s f e a s i b l e f o r the i d e n t i f i c a t i o n of Skeena River s t e e l h e a d i n the commercial salmon f i s h e r y . The technique p r o v i d e s a means fo r s t a t i s t i c a l l y s e p a r a t i n g each stock and f o r c l a s s i f y i n g mixed stocks with measurable bounds of c o n f i d e n c e at any p o i n t i n time. Secondly, the technique can be used to c o n s t r u c t stock s p e c i f i c run-timing curves through the f i s h e r y ; with f u r t h e r 1 1 7 i n v e s t i g a t i o n to q u a n t i f y y e a r l y v a r i a b i l i t y i n ru n - t i m i n g , the technique can be used to p r e d i c t the f u t u r e impacts to any stock from v a r i o u s p a t t e r n s of commercial f i s h i n g . T h i r d l y , the technique i s f l e x i b l e and can t h e r e f o r e be e a s i l y m o d i f i e d as new i n f o r m a t i o n becomes a v a i l a b l e . F o u r t h l y , the technique i s e a s i l y implementable and does not r e q u i r e l a r g e c a p i t a l expenditure or e f f o r t . Only f u r t h e r e x t e n s i o n of the r e s u l t s of t h i s t h e s i s w i l l e s t a b l i s h the long term u s e f u l n e s s of s c a l e p a t t e r n a n a l y s i s as a p r a c t i c a l management t o o l . 1 18 LITERATURE CITED Amos, M.H., R. Murai and R. Pearson. 1963. 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U n i v e r s i t y of B r i t i s h Columbia, Vancouver, Canada. 115pp. T a y l o r , G.D. 1968. Report on the p r e l i m i n a r y survey of the Skeena R i v e r drainage streams. Unpubl. M.S. B.C. F i s h and W i l d l i f e Branch, 42pp. Thorpe, J.E., and K.A. M i t c h e l l . 1981. Stocks of A t l a n t i c salmon (Salmo s a l a r ) i n B r i t a i n and I r e l a n d : d i s c r e t e n e s s and c u r r e n t management. Can. J . F i s h . Aquat. S c i . 38:1576- 1590. Thorpe, R.S. 1976. B i o m e t r i c a n a l y s i s of geographic v a r i a t i o n and r a c i a l a f f i n i t i e s . B i o l . Rev. 51:407-452. Todd, I. S t . P., and P.A. L a r k i n . 1971. G i l l n e t s e l e c t i v i t y on Sockeye (Oncorhynchus nerka) and Pink salmon (0. qorbuscha) of the Skeena R i v e r System, British"*Columbia. J . F i s h . Res. Bd. Can. 28:821-842. Tredger, D. 1984. Skeena R i v e r boat shocking program:summary r e p o r t . F i s h e r i e s H a b i t a t and Improvement s e c t i o n . B.C. F i s h e r i e s Branch. V i c t o r i a . T s u y u k i , H., and S. N. W i l l i s c r o f t . 1977. Swimming stamina d i f f e r e n c e s between g e n o t y p i c a l l y d i s t i n c t forms of rainbow t r o u t (Salmo q a i r d n e r i ) and s t e e l h e a d t r o u t . J . F i s h . Res. Bd. Can. 34:996-1003. U t t e r , F.M. 1981. B i o l o g i c a l c r i t e r i a f o r d e f i n i t i o n of s p e c i e s and d i s t i n c t i n t r a s p e c i f i c p o p u l a t i o n s of anadromous salmonids under the U.S. Endangered s p e c i e s Act of 1973. Can. J . F i s h . Aquat. S c i . 38:1626-1635. 1 27 U t t e r , F.M., and F.W. A l l e n d o r f . 1977. Determination of the breeding s t r u c t u r e of s t e e l h e a d p o p u l a t i o n s through gene frequency a n a l y s i s , pages 44-54: i n T . J . H a s s l e r and RR. VanKirk ( e d i t o r s ) Genetic i m p l i c a t i o n s of s t e e l h e a d management. C a l i f . Coop. F i s h . r e s . U n i t , A r e a t a . Whately, M.R. 1977. K i s p i o x River s t e e l h e a d t r o u t : the 1975 s p o r t f i s h e r y and l i f e h i s t o r y c h a r a c t e r i s t i c s from a n g l e r s ' c a t c h e s . B.C. F i s h and W i l d l i f e Branch, F i s h . Tech. C i r c . No. 30, 22pp. Whately, M.R., W.E. Chudyk, and M.C. M o r r i s . 1978. Morice River s t e e l h e a d t r o u t : the 1976 and 1977 sport f i s h e r y and l i f e h i s t o r y c h a r a c t e r i s t i c s from a n g l e r s ' c a t c h e s . B.C. F i s h and W i l d l i f e Branch, F i s h . Tech. C i r c . No. 36, 25pp. Winter, G.W., C.B. Schreck and J.D. M c l n t y r e . 1980. M e r i s t i c v a r i a t i o n i n four stocks of s t e e l h e a d t r o u t (Salmo q a i r d n e r i ) . Copeia. 1980:160-162. W i t h l e r , L. 1966. V a r i a b i l i t y in l i f e h i s t o r y c h a r a c t e r i s t i c s of s t e e l h e a d t r o u t (Salmo q a i r d n e r i ) along the P a c i f i c coast of North America. J . F i s h . Res. Bd. Canada.23:365-393. Worlund, D.D. and R.A. F r e d i n . 1962. D i f f e r e n t i a t i o n of s t o c k s , pages 143-153 i n Symposium on Pink salmon, H.R. Macmillan L e c t u r e s in F i s h e r i e s , Univ. B r i t i s h Columbia, Vancouver, Canada. 128 APPENDICES 129 Appendix A: D i s c r i m i n a n t A n a l y s i s and C l a s s i f i c a t i o n D i s c r i m i n a n t a n a l y s i s reduces the v a r i a b l e v e c t o r s f o r i n d i v i d u a l s and c e n t r o i d s to s i n g l e values ( c a n o n i c a l v a r i a b l e s , Di) by forming l i n e a r combinations of the o r i g i n a l v a r i a b l e s weighted a c c o r d i n g to t h e i r c o n t r i b u t i o n to between groups d i s c r i m i n a n c e (using p a r t i a l one way ANOVA v a r i a b l e F scores as entry c r i t e r i a ) . The d i s c r i m i n a n t f u n c t i o n s are of the form: D i = d Z + d Z + ....+d z i 1 i1 2 i2 p i p where Di i s the d i s c r i m i n a n t score, f o r the i t h i n d i v i d u a l , d1, d2, ....dp are the weighting c o e f f i c i e n t s and z i 1 , z i 2 . . . z i p are s t a n d a r d i z e d v a l u e s of the measurements from the i t h i n d i v i d u a l . The weighting c o e f f i c i e n t s are c a l c u l a t e d so that the Di are standard normal v a r i a b l e s and the grand mean d i s c r i m i n a n t score i s zero with a standard d e v i a t i o n of one. D i s c r i m i n a n t f u n c t i o n s , t h e i r number being one l e s s than the number of groups, are orthogonal to each other and d e s c r i b e group v a r i a t i o n along d i f f e r e n t d i r e c t i o n a l axes ( f i g u r e 6 ) . The major assumptions of d i s c r i m i n a n t a n a l y s i s are a) that the groups being d i s t i n g u i s h e d are i d e n t i f i a b l e (b) that the v a r i a b l e system being used i s m u l t i v a r i a t e normal and (c) that the groups a l l share a common v a r i a n c e - c o v a r i a n c e s t r u c t u r e . Assumption b was t e s t e d as best p o s s i b l e by the examination of u n i v a r i a t e frequency d i s t r i b u t i o n s . Assumption c was t e s t e d by the a p p l i c a t i o n of Box's m u l t i v a r i a t e M t e s t (Nie, 1975). C l a s s i f i c a t i o n m a t r i c e s (confusion m a t r i c e s , Johnson and Wichern, 1982) are d e r i v e d in d i s c r i m i n a n t a n a l y s i s through the use of c l a s s i f i c a t i o n f u n c t i o n s ; one f o r each stock. An e m p i r i c a l measure of group (stock) s e p a r a b i l i t y i s obtained by c l a s s i f y i n g the i n d i v i d u a l s used to c o n s t r u c t the d i s c r i m i n a n t f u n c t i o n s i n t o t h e i r most probable groups of o r i g i n using the c l a s s i f i c a t i o n f u n c t i o n s . Lachenbruch's (1975) holdout c l a s s i f i c a t i o n procedure ( j a c k n i f i n g ) was used in t h i s study to reduce the b i a s i n p r e d i c t i n g c l a s s i f i c a t i o n e r r o r r a t e s when us i n g the same i n d i v i d u a l s f o r both d i s c r i m i n a t i o n and c l a s s i f i c a t i o n . I n c i d e n t a l l y caught s t e e l h e a d from the 1984 commercial f i s h e r y p r o v i d e d the samples of unknown stock composition to be c l a s s i f i e d to stock of o r i g i n . Of primary concern were the r e l a t i v e p r o p o r t i o n s of each stock p r e d i c t e d to be present d u r i n g each week of the salmon f i s h e r y . Worlund and F r e d i n (1962) f i r s t d e s c r i b e d l i n e a r equations which a d j u s t the p r e d i c t e d p r o p o r t i o n a l estimates from the mixed sample to account f o r the e r r o r s i n a s s i g n i n g i n d i v i d u a l s of known o r i g i n (the l e a r n i n g samples). Cook and Lord (1978) extended the procedure to more than two stocks u s i n g matrix a l g e b r a . Using t h e i r methodology, the c l a s s i f i c a t i o n accuracy estimated by the holdout procedure f o r a given l e a r n i n g sample i s represented by the square matrix C, where the element C i j i s the p r o p o r t i o n of the sample from stock j that i s c l a s s i f i e d as stock i . L e t t i n g r be a column v e c t o r r 1 , r 2 , r 3 , . . . . r i , where r i i s the p r o p o r t i o n 130 of the mixed sample c l a s s i f i e d as stock I then: -1 U = C r where each element of the column v e c t o r U (U1, U2,...Ui) i s the estimate of the p r o p o r t i o n of stock I in the commercial sample a f t e r c o r r e c t i n g f o r the e r r o r s i n c l a s s i f y i n g i n d i v i d u a l s of known o r i g i n . V a r i a n c e s about these p o i n t estimates (Ui) were estimated using the formulae of P e l l a and Robertson (1979) and a 90% confidence i n t e r v a l was c a l c u l a t e d f o r each es t i m a t e . The c o r r e c t i o n procedure of Cook and Lord (1978) i s b a s i c a l l y a m o d i f i c a t i o n of the two stock l e a r n i n g sample s c e n a r i o : C l a s s i f i e d Stock A c t u a l Stock A B A Aa • Ab =C B Ba Bb where Aa, Ab, Ba, and Bb are the p r o p o r t i o n s of f i s h from t h e i r r e s p e c t i v e stocks c o r r e c t l y (Aa, Bb) and i n c o r r e c t l y (Ab, Ba) c l a s s i f i e d . Aa and Bb are the estimated p r o b a b i l i t i e s of c o r r e c t l y c l a s s i f y i n g an unknown i n d i v i d u a l which a c t u a l l y belongs to one of those stocks whereas Ab and Ba are the estimated p r o b a b i l i t i e s of m i s c l a s s i f y i n g an i n d i v i d u a l a c t u a l l y belonging to one of the s t o c k s as being from the o t h e r . In a mixed f i s h e r y sample, the p r o p o r t i o n s of f i s h a s s i g n e d by d i s c r i m i n a n t a n a l y s i s to each stock (Pa, Pb) represent both the c o r r e c t l y a s s i g n e d i n d i v i d u a l s p l u s the u n c o r r e c t l y assigned i n d i v i d u a l s . S o l v i n g f o r Na and Nb, the a c t u a l p r o p o r t i o n s of each stock present i n a mixture,- i s by s o l u t i o n of two simultaneous equations: Pa = Aa Na + Ab Nb Pb = Ba Na + Bb Nb or -1 r = C * U . . U = C r which reduces to the matrix adjustment procedure of Cook and Lord (1978). The elements of U can be g r e a t e r than zero, l e s s than zero, or equal to zero depending upon the p r o p o r t i o n of a given stock a c t u a l l y i n the commercial sample. P r o p o r t i o n a l estimates l e s s than zero i n d i c a t e d the absence of a p a r t i c u l a r stock i n the sample. Any samples r e s u l t i n g i n p r o p o r t i o n a l estimates l e s s than zero i n t h i s study were reanalyzed using d i s c r i m i n a n t models which d i d not i n c l u d e those s t o c k s . Appendix T.1. Age composition s t r u c t u r e f o r the f i v e stocks used i n the study. AGE CLASS + + + + + + + + RI SEX 2. 1 2.2 3.1 3.2 3.3 4.1 4.2 4.3 RS TOTA1 1 M 0 0 4 9 4 3 13 1 8 42 F 0 0 1 14 1 2 19 1 12 50 % - - .05 .25 .05 .05 .35 .02 .22 1 2 M 0 0 8 4 1 10 9 1 2 35 F 0 0 5 4 0 28 10 0 7 54 % - - . 1 5 .09 .01 .43 .22 .01 .10 1 3 M 0 0 1 12 12 1 15 8 5 54 F 1 0 2 16 05 1 1 1 3 10 49 % .01 - .03 .29 .16 .02 .25 . 1 1 .14 1 4 M 0 0 2 21 1 1 7 0 2 34 F 0 0 1 35 0 3 17 1 0 57 O. -b - - .03 .62 .01 .04 .26 .01 .02 1 5 M 0 0 0 3 6 1 1 4 1 1 1 36 F 0 0 0 9 4 0 31 3 7 54 % - - - .13 . 1 1 .01 .50 . 16 .09 1 TOTALS % .002 - .05 .27 .09 . 1 1 .31 .06 . 1 2 1 RI KEY : 1 = ZYMOETZ, 1974,1978 n = 92 2 = MORICE , 1977 n = 90 3 = KISPIOX, 1975 n=l03 4 = BABINE , 1978 n = 9l 5 = SUSTUT , 1977,1983 n = 90 Appendix T . 2 . S i z e s at age f o r the f i v e stocks used i n the study. Reported are the means, standard d e v i a t i o n s and sample s i z e s f o r the major age c l a s s e s . Age Kispiox Zymoetz Morice Babine Sustut L WT L WT L WT L WT L WT 3.1 + M X 61.1 2.3 56.7 1 .8 58.3 1 .8 57.3 2.0 - -s 0 0 2.63 0.5 4.14 0.5 1 .27 0 - -n 1 1 4 4 7 7 2 1 - - F X 59.7 2.9 67.0 2.7 55.8 1 .6 60.0 2.0 - -s 2.63 0.9 0 0 5.51 0.5 0 0 - -n 2 2 1 1 6 6 1 1 - 3.2+ M X 86.5 7.7 82.0 5.6 75.3 4.0 81.5 5.3 84. 1 6.0 s 5.51 1 .3 8.46 2.6 3.33 0.9 6.39 1 .0 4.47 0.9 n 10 10 7 7 3 3 22 22 4 2 F X 82.8 5.9 75.5 4.1 73.2 3.3 78.5 4.6 77.0 4. 1 s 6.53 1 .8 3.49 0.6 5.83 0.4 4.72 0.9 4.23 0.9 n 17 17 15 15 5 5 20 20 8 5 3.3 + M X 99.9 10.2 91 .4 7.5 91 .5 7.5 91.4 7.4 93.3 8.9 s 8.25 2.4 6.59 1.8 0 0 0 0 3.37 0.9 n 12 12 5 5 1 1 1 1 6 4 F X 87.3 7.5 88.9 6.9 - - - - 86.4 6.1 s 8.88 2. 1 0 0 - - - - 6.58 1.2 n 5 5 1 1 - - — - 4 3 4.1 + M X 55.9 2.0 57.8 1.9 59.6 1 .8 60.3 2.0 55.9 1 .8 s 0 0 1 .36 0.4 4.68 0.4 0 0 0 0 n 1 1 3 3 10 10 1 1 1 1 X 55.9 1 .8 62.8 2.4 56.9 1 .5 60.5 2.0 63.5 2.7 s 0 0 2.47 0.7 3.43 0.4 0 0 0 0 n 1 1 2 2 30 30 1 1 1 1 4.2+ M X 90.0 8.2 80. 1 5.0 83.5 5.3 73. 1 3.4 84.6 6.8 5 9.45 2.3 3.91 0.5 7.77 1 .2 8.52 0.9 7.89 2.4 n 13 13 15 15 7 7 5 5 13 10 F X 77.9 5.3 74.9 4.6 71.9 3.4 74.3 4.4 77.2 4.6 s 8.35 1.0 4.72 1.8 2.58 0.6 1 .03 0.4 3.45 0.9 n 12 12 18 18 14 14 7 7 31 22 4.3+ M X 94.5 8.9 96.5 8.6 - - - - 96. 1 8.9 s 7.84 1.7 0 0 - - - - 4.02 1 .2 n 1 1 11 1 1 - - - — 10 10 X 87.2 6.7 79.5 4.5 - - - - 87.6 6.0 s 5.26 1.3 0 0 - - - - 1 .25 0 n 3 3 1 1 - - - — 3 1 RS M X 79.1 5.4 80.1 5.4 66.5 3.0 75.2 4.1 78.7 5.4 s 5.13 0.9 6.10 1 .7 9.19 1 .4 11.1 2.7 0 0 n 3 3 9 9 2 2 2 2 1 1 F X 89.4 7.6 84.2 5.8 82.6 5.1 - - 84.4 5.9 s 5.30 1.6 5.40 1 .2 5.37 1 .4 - - 2.91 1 .1 n 10 10 1 1 1 1 7 7 - - 7 4 Key M=males F=females X=mean s=S.D n=sample s i z e 1 3 3 ix T . 3 . V a r i a b l e means, standard d e v i a t i o n s , and one way ANOVA F s t a t i s t i c s f o r the f i v e stocks used i n the study by smolt age 3 ( l e a r n i n g samples). GROUP » K I S P I O X COPPER SUSTUT V A R I A B L E 1 PG 0 . 8 9 3 6 2 0 . 4 0 5 4 1 0 . 2 6 9 2 3 3 FWA 3 . 0 0 0 0 0 3 OOOOO 3 . OOOOO 4 SWA 2 . 4 8 9 3 6 2 . 2 7 0 2 7 2 . 7 3 0 7 7 5 L 87 . 2 3 4 0 2 77 9 3 7 8 2 84 . 31 152 6 WT 7 . 2 7 2 3 4 4 . . 8 8 3 7 8 6 . OOOOO 7 SEX 1 . 4 2 5 5 3 1 . 4 3 2 4 3 1 . 3 8 4 6 1 8 A 1 0 . 0 9 2 3 4 0 . 0 9 3 5 1 0 . 0 9 0 0 0 9 A2 0 . 14362 0 . 1 5 5 6 8 0 . 15462 10 A4 0 . 2 1043 0 . 2 0 1 8 9 0 . 23 192 1 1 A5 6 . 7 2 3 4 0 5 . . 6 7 5 6 8 6 . 846 15 12 A6 2 . 7 6 5 9 6 2 . . 3 5 1 3 5 2 . 9 2 3 0 8 13 B1 0 . 0 4 7 0 2 0 . . 0 4 8 6 5 0 . 0 3 6 5 4 14 B2 0 . 0 9 7 4 5 0 . 0 9 8 3 8 0 . 0 9 5 0 0 IS B3 0 . 1 4 S S 3 0 . . 1 5 0 8 1 0 . 15038 16 B4 0 . 2 9 0 4 3 0 . . 2 9 4 5 9 0 . 3 0 2 6 9 17 6 5 1 1 . 5 9 5 7 4 1 1 . 5 9 4 5 9 1 1 . 5 3 8 4 6 18 B6 5 . 702 13 s . . 5 6 7 5 7 5 . 42 308 19 CI 0 . 0 5 1 2 8 0 . . 0 5 1 8 9 0 . 0 4 3 8 5 2 0 C2 0 . 10787 0 . 1 0 6 2 2 0 . 1 1385 21 C3 0 . 16362 0 . . 1 6 4 3 2 0 . 17692 22 C4 0 . 3 4 2 3 4 0 3 5 5 1 4 0 . 3 7 6 5 4 23 C 5 12. 5 1 0 6 4 12. . 6 7 5 6 8 1 2 . 5 7 6 9 2 24 C6 5 . 8 5 1 0 6 5 . 9 7 2 9 7 5 . 8 8 4 6 1 25 01 0 . 0 8 4 8 9 0 . 0 8 8 1 1 0 . 0 6 7 3 1 2 6 D2 0 . 1 8 1 2 8 0 . 1 8 0 5 4 0 . 16500 27 0 3 0 . 2 8 7 2 3 0 . 2 7 7 8 4 0 . 2 6 8 8 5 28 0 4 1 . 6 5 3 1 9 1 . 6 9 4 5 9 1 . 5 3 6 1 5 29 D5 35 . 7 2 3 4 0 35 . 10809 32 . 15384 3 0 D6 16 . 0 0 0 0 0 15 . 4 5 9 4 6 15 . 6 5 3 8 5 COUNTS 4 7 . 3 7 . 2 6 . F TO BABINE MORICE ALL G P S . ENTER DF = 4 186 0 . 2 9 3 1 0 0 . 6 9 5 6 5 0 . 5 0 7 8 5 3 3 5 0 3 OOOOO 3 . OOOOO 3 OOOOO 0 . 0 2 0 1 7 2 4 1 . 652 17 2 . 2 3 5 6 0 9 . 876 77 . 3 3 2 7 5 66 2 1 7 3 8 79 4 9 7 8 9 22 . 5 9 7 4 5 9 4 0 3 2 . 8 0 4 3 5 5 28534 31 . 745 1 3 9 6 5 5 1 . 4 3 4 7 8 1 . 4 1 3 6 1 0 . 0 6 9 0 . 0 9 3 4 5 0 10087 0 . 0 9 3 6 1 0 . 8 2 9 0 14983 0 16522 0 . 15194 2 . 9 7 0 0 2 3 0 1 7 0 . 2 4 7 8 3 0 2 2 2 2 0 3 . 8 0 3 7 3 2 7 5 9 7 . 8 2 6 0 9 6 8 5 3 4 0 6 . 266 3 . 0 6 8 9 6 3 . 2 6 0 8 7 2 . 8 5 8 6 4 3 . 9 3 5 0 0 4 9 3 1 0 . . 0 4 2 6 1 0 . 0 4 6 0 7 6 . 6 7 7 0 . 1 0 5 6 9 0 0 9 130 0 . 0 9 9 0 6 3 315 0 16086 0 14 174 0 . 1 5 1 4 1 4 . 154 0 . 3462 1 0 . 2 4 7 8 3 0 . 3 0 4 7 1 8 . 178 13. . 2 2 4 1 4 10. . 4 7 8 2 6 11 , 9 4 7 6 4 6 . 48 1 6 . 2 5 8 6 2 4 . . 6 5 2 1 7 5 . 6 8 0 6 3 7 . 0 8 0 0 . 0 5 3 4 5 0 . 0 4 0 8 7 0 . 0 4 9 7 9 7 . 169 0 . 1 1 5 8 6 0 . 0 9 1 7 4 0 . 1 0 8 8 5 9 . 277 0 17776 0 14652 0 16780 7 933 0 3 8 6 7 2 0 . 2 8 9 5 7 0 . 3 5 6 6 0 4 . SOO 14 . 0 5 1 7 2 10. 9 5 6 5 2 12 8 3 2 4 6 5 . 585 6 . 5 5 1 7 2 5 . . 0 8 6 9 6 6 . .OOOOO 5 . 234 0 . 0 8 5 5 2 0 . 0 8 0 0 0 0 0 8 2 7 2 5 . 281 0 . 1 9 0 8 6 0 . 17478 0 . , 1 8 1 0 5 3 332 0 . 3 0 6 5 5 0 2 8 6 0 9 0 28864 4 . 601 1 . 7 8 2 0 7 1 . 7 0 4 3 5 1. 6 9 0 5 7 2 . 6 8 9 34 . 6 3 7 9 2 34 . 4 3 4 7 7 34 . . 6 3 3 5 0 1 . 678 15 . 9 1 3 7 9 15 . 5 6 5 2 2 15 . 7 6 9 6 3 0 . 389 58 . 2 3 . 191 . STANDARD D E V I A T I O N S GROUP V A R I A B L E K I S P I O X COPPER SUSTUT BABINE 1 PG 1 . 3 2 2 6 1 0 . 9 2 6 7 4 0 . 7 2 4 3 0 0 . 6 7 5 6 0 3 FWA 0 . 0 0 . 0 0 . 0 0 . 0 4 SWA 0 . 7481 1 0 . 8 7 0 7 8 0 . 8 2 7 4 1 0 . 3 9 6 9 8 5 L 9 . 7 4 7 3 6 10 . 7 4 7 0 4 7 . 2 6 8 5 7 7 . 6 1405 6 WT 2 . 0 9 0 3 2 2 . 0 3 7 9 0 1 . 7 1 2 7 7 1 12475 7 SEX 0 . 4 9 9 7 7 0 . 5 0 2 2 5 0 . 496 14 0 . 4 9 3 4 5 8 A1 0 . 0 2 0 9 8 0 . 0 2 5 3 0 0 . 02 135 0 . 0 2 0 9 1 9 A2 0 . 0 2 4 6 2 0 . 0 2 3 8 7 0 . 0 2 9 7 0 0 . 0 2 5 17 10 A4 0 . 0 5 3 7 3 0 . 0 3 8 6 5 0 . 0 5 4 8 5 0 . 0 4 9 19 1 1 A5 2 . 0 5 0 4 7 1 . 2 7 0 4 8 1 . 8 6 9 5 9 1 . 6 4 7 8 3 12 A6 1 . 12699 0 . 5 8 7 6 6 0 . 9 7 6 6 5 0 . 9 3 4 0 0 13 B1 0 . 0 0 9 9 8 0 . 01 159 0 . 0 1 2 6 3 0 . 01 197 14 B2 0 . 0 1 6 8 7 0 . 0 1 7 5 6 0 . 0 1 9 0 3 0 . 0 1 8 3 6 15 8 3 0 . 0 2 3 8 5 0 . 0 2 1 1 3 0 . 0 2 4 5 7 0 . 0 2 3 6 4 16 B4 0 . 0 6 6 5 9 0 . 0 6 5 1 7 0 . . 0 6 3 7 2 0 0 9 7 13 17 B5 2 . 14334 2 . 2 5 4 1 2 2 . 6 8 6 7 2 2. 84 106 18 B 6 1 . 12123 1 , 3 0 2 5 7 1 . . 3 6 1 5 6 1 3 9 6 2 4 19 C1 0 . 0 1 2 9 6 0 . , 0 1 2 2 1 0 . 0 1 0 6 1 0 . 01 132 2 0 C2 0 . 0 1 4 8 8 0 . 0 2 0 8 6 0 . 0 1 5 7 7 0 0 1 6 9 7 21 C3 0 . . 0 2 5 2 3 0 . 0 2 8 8 2 0 , 0 2 2 2 3 0 . 0 2 5 2 7 22 C4 0 . 0 8 3 5 2 0 . 0 8 9 0 9 0 . 1 3 3 2 3 0 . 1 1 0 6 3 23 C 5 2 . 9 1 0 7 8 2 . 9 2 5 5 0 3 . 5 9 0 8 0 2 . 5 6 4 4 1 24 C6 1 . 3 6 6 9 8 1 . 3 2 2 5 9 1 . 8 8 3 1 2 1 . 2 0 1 9 3 2 5 01 0 . 0 1 6 7 9 0 . 0 2 4 5 9 0 . 0 2 4 7 5 0 0 1 6 1 3 26 D2 0 . 0 2 6 5 1 0 . 0 4 0 0 7 0 . 0 2 4 7 0 0 . 0 3 0 7 4 27 0 3 0 . 0 3 8 2 0 0 . 0 4 9 9 5 0 . 0 3 2 4 1 0 . 0 4 0 2 4 2B D4 0 . 3 8 3 8 5 0 . 3 0 1 3 8 0 . 3 2 8 8 3 0 . 2 6 8 3 9 29 D5 6 . 3 3 0 3 9 s . 5 8 6 6 0 5 . 7 5 9 8 0 5 . 1 5 6 1 4 3 0 0 6 2 . 5 7 9 1 7 2 . 2 8 0 2 8 2 . 2 9 6 8 2 . 2 . 3 0 3 9 6 MORICE 0 . 9 7 3 9 7 0 . 0 0 . 8 3 1 6 8 1 1 . 6 1 1 9 3 1 . 5 3 6 3 7 0 . 5 0 6 8 7 0 . 0 2 3 1 4 0 . 0 3 2 3 2 0 . 0 7 5 8 0 2 . 6 2 2 4 9 . 4 8 3 7 7 . 0 1 1 7 6 . 0 2 2 0 1 . 0 2 2 8 9 . 0 5 7 0 5 19233 1 . 0 7 0 6 3 0 . 0 0 7 9 3 0 . 0 1 4 0 3 0 . 0 1 7 7 4 . 0 5 6 5 3 . 6 3 7 0 2 9 4 9 3 1 . 0 1 7 0 6 . 0 3 3 6 9 . 0 5 2 8 9 . 3 9 7 7 3 . 4 7 2 5 0 . 0 8 5 1 4 A L L G P S . 0 . 9 5 9 9 2 0 . 0 0 . 7 1 2 2 4 9 . 3 0 9 4 8 . 7 1 6 2 5 4 9 8 6 8 . 0 2 2 1 6 . 0 2 6 3 9 . 0 5 3 1 8 . 8 6 2 1 4 1 . 0 1 8 2 8 . 0 1 1 5 0 . 0 1 8 4 2 . 0 2 3 2 7 . 0 7 5 7 7 . 4 7 6 2 4 . 2 7 3 3 6 . 0 1 1 5 0 . 0 1 6 8 5 0 . 0 2 4 8 5 0 . 0 9 8 8 7 2 . 7 9 5 9 1 1 . 3 5 1 5 2 0 . 0 1 9 5 8 0 . 0 3 1 4 7 . . 0 4 2 5 7 . 3 3 0 6 6 . 7 8 8 9 7 . 3 4 5 5 2 1 . O O. O . O . 1 . O. 0 . O . o . 2 . 1 . O . 0 . o . 0 . 5 . 2 . 134 Appendix T . 4 . V a r i a b l e means, standard d e v i a t i o n s , and one way ANOVA F s t a t i s t i c s for the f i v e stocks used in the study by smolt age 4 ( l e a r n i n g samples). GROUP K I S P I O X COPPER SUSTUT BABINE MORICE ALL G P S . ENTER V A R I A B L E DF= 4 2 3 ' 1 PG 0 . 4 3 2 4 3 0 . 2 9 1 6 7 0 . 3 3 8 9 8 0 . 2 0 0 0 0 0 . 4 3 0 7 7 0 . 3 5 1 4 6 0 . 5 3 9 3 FWA 4 . 0 0 0 0 0 4 . 0 0 0 0 0 4 . 0 1 6 9 5 4 . 0 0 0 0 0 4 . 0 1 5 3 8 4 . 0 0 8 3 7 0 . 4 6 4 4 SWA 2 . 6 4 8 6 5 2 . 5 6 2 5 0 2 . 3 8 9 8 3 1 . 9 0 0 0 0 1 . 5 8 4 6 1 2 . 184 10 14 . 778 5 L 84 . 6 9 1 8 8 77 . 0 0 6 2 4 8 3 . 3 8 9 8 2 72 . 9 8 6 6 6 6 5 . 04 308 7 6 . 0 1 3 7 9 4 1 . 365 6 WT 6 . 7 3 5 1 3 4 . 5 6 4 5 8 5 . 9 4 9 1 5 .1 . 10333 2 . 6 2 9 2 3 4 . 6 5 8 1 6 5 0 . 272 7 SEX 1 . 5 1 3 5 1 1 . 4 5 8 3 3 1 . 4 0 6 7 B 1 . 3 0 0 0 0 1 . 3 0 7 6 9 1 . 3 9 3 3 0 1 . 565 8 A1 0 . 0 9 3 7 8 0 . 0 9 6 8 7 0 . 0 9 2 2 0 0 . 10000 0 . 0 9 8 1 5 0 . 0 9 5 9 8 1 . 0 0 7 9 A2 0 . 14568 0 . 15167 0 . 15559 0 . 15167 0 . 15800 0 . 15343 1 8 . 4 6 0 10 A4 0 . 18216 0 . 18708 0 . 2 1 136 0 . 2 2 9 0 0 0 . 2 2 3 6 9 0 . 2 0 7 5 3 . 6 0 7 1 1 A5 5 . 4 8 6 4 9 5 . 354 17 6 . 15254 7 . 4 0 0 0 0 6 . 7 3 8 4 6 6 . 20502 18 . 457 12 A6 2 . 3 7 8 3 8 2 . 1 2 5 0 0 2 . 5 2 5 4 2 2 . 9 3 3 3 3 2 646 15 2 . 5 0 6 2 8 7 . 150 13 B1 0 . 04 351 0 . 0 4 7 5 0 0 . 0 4 3 0 5 0 0 4 8 6 7 0 . 0 4 0 9 2 0 . 044 14 3 . 533 14 B2 0 . 0 9 1 0 8 0 . 0 9 9 1 7 0 . 10220 0 . 0 9 9 3 3 0 . 0 9 108 0 . 0 9 6 4 9 4 . 522 15 B3 0 . 13784 0 . 15021 0 . 16068 0 . 15167 0 . 13723 0 . 14753 1 0 . 842 16 B4 0 . 2 4 1 3 5 0 . 24 146 0 . 2 7 3 3 9 0 2 8 1 6 7 0 . 2 2 9 8 5 0 . 2 5 1 2 1 7 . 404 17 B 5 1 0 . 4 3 2 4 3 9 . 5 0 0 0 0 9 . 8 9 8 3 0 1 1 . 0 0 0 0 0 9 . 7 8 4 6 1 1 0 . 0 0 8 3 7 3 . 401 18 B 6 4 . 9 7 2 9 7 4 . 3 7 5 0 0 4 . 7 2 8 8 1 5 . 2 0 0 0 0 4 . 6 7 6 9 2 4 . 7 4 0 5 9 4 . 126 19 C1 0 . 0 4 6 2 2 0 . 0 4 8 3 3 0 . 0 4 3 7 3 0 . 0 5 0 6 7 0 . 04 2 0 0 0 . 0 4 5 4 4 3 . 8 3 5 2 0 C2 0 . 10432 0 . 1 0 2 5 0 0 . 10949 0 . 10700 0 . 0 9 4 6 2 0 . 10293 5 . 5 7 0 21 C3 0 . 15865 0 . 15833 0 . 17339 0 . 16 100 0 . 14338 0 . 15837 1 1 . 348 22 C4 0 . 2 7 2 9 7 0 . 2 7 6 4 6 0 . 2 9 7 9 7 0 . 2 7 6 3 3 0 . 2 3 9 3 8 0 . 27 113 7 . 6 4 8 23 C 5 1 0 . 16216 10 . 4 3 7 5 0 1 0 . 25424 10 . 6 6 6 6 7 9 . 9 6 9 2 3 10 . 2 5 1 0 5 0 934 24 c e 5 . 0 8 1 0 8 4 . 87 5 0 0 4 . 9 4 9 1 5 5 . 0 3 3 3 3 4 . 6 9 2 3 1 4 . 8 9 5 4 0 0 . 9 5 9 25 01 0 . 0 7 8 3 8 0 . 0 8 1 6 7 0 . 0 7 2 3 7 0 . 0 8 9 0 0 0 . 0 7 3 5 4 0 . 0 7 7 5 7 4 . 399 26 0 2 0 . 17568 0 . 1777 1 0 . 17339 0 . 19767 0 . 1743 1 0 . 1779 1 3 . 5 3 5 27 0 3 0 . 2 9 1 0 8 0 . 2 8 6 6 7 0 . 2 7 6 6 1 0 . 3 1533 0 . 2 8 2 6 2 0 . 2 8 7 3 6 4 . 588 28 •4 1 . 8 5 5 4 0 1. 7 6 4 7 9 1. 6 3 0 3 4 1 . 7 9 1 0 0 1 . 6 6 6 3 1 1 . 7 2 2 1 3 4 . 325 29 D5 3 8 . 0 5 4 0 5 3 6 . 16666 3 2 . 7 7 9 6 5 35 . 2 9 9 9 9 33 . 8 1538 34 . 8 7 4 4 7 5 . 798 3 0 0 6 16 . 5 9 4 5 9 15 . 8 9 5 8 3 1 5 . 627 12 15 . 7 0 0 0 0 15 . 3 3 8 4 6 15 . 76 15 1 1 . 766 31 E 1 0 . 0 5 2 1 6 O. 0 5 1 2 5 0 . 0 4 9 8 3 0 . 0 5 2 6 7 0 . 0 4 2 7 7 0 . 0 4 8 9 1 5 . 637 32 E2 0 . 1 1 162 0 . 10667 0 . 12220 0 . 1 1500 0 . 0 9 5 6 9 0 . 10933 15 . 167 33 E 3 0 . 16784 0 . 16396 0 . 19068 0 . 17633 0 . 14 8 0 0 0 . 16837 2 1 . 306 34 E4 0 . 2 7 6 2 2 0 . 3 1 2 9 2 0 . 3 7 2 2 0 0 . 3 4 7 3 3 0 . 2 7 6 4 6 0 . 3 1 6 2 8 12 . 8 1 9 35 E 5 9 . 7 0 2 7 0 1 0 . 8 5 4 1 7 12 . 1 1864 1 1 . 7 0 0 0 0 1 1 . 13846 1 1 . 17 155 4 . 9 9 0 36 E6 4 . 6 2 1 6 2 4 . 8 9 S 8 3 5 . 8 1 3 5 6 5 . 5 6 6 6 7 5 . 2 0 0 0 0 5 . 2 4 6 8 6 4 . 938 COUNTS 37 . 48 . 59 . 3 0 . 65 . 239 . STANDARD D E V I A T I O N S GROUP K I S P I O X COPPER SUSTUT BABINE MORICE A L L G P S . V A R I A B L E 8 3 9 6 0 1 PG 0 . 9 5 8 6 0 0 . 7 7 0 6 9 0 . 8 8 2 9 8 0 . 5 5 0 B 6 0 . 8 8 3 3 4 0 3 FWA 0 . , 0 0 . 0 0 . 1 3 0 1 9 0 . 0 0 . 1 2 4 0 3 0 09 170 4 SWA 0 . 8 5 6 8 7 1 18333 0 . 6 1 6 3 5 0 . 4 0 2 5 8 0 . 8 9 9 5 2 0 . 8 5 4 2 5 5 L 10 . . 9 0 0 8 6 8 . 3 3 5 0 9 8 . 4 0 3 6 8 5 . 5 1 1 7 2 10 . 8 1 0 6 3 9 . 2 4 4 8 9 6 WT 2 . . 1 4 5 5 6 1 . 5 0 3 2 5 1 . , 8 0 4 5 3 0 . 7 6 0 8 9 1 . 5 0 6 1 0 1 . 6 3 1 3 5 7 SEX 0 . . 5 0 6 7 1 0 . , 5 0 3 5 3 0 4 9 5 4 5 0 . 4 6 6 0 9 0 . 4 6 5 1 3 0 . 4 8 7 2 0 8 A 1 0 . . 0 2 4 8 7 0 . 0 2 0 8 5 0 . . 0 2 0 0 9 0 . 0 2 1 3 3 0 . 0 2 0 9 8 0 . 0 2 1 4 3 9 A2 0 . . 0 2 5 8 8 0 . 0 2 5 7 9 0 . , 0 2 4 3 0 0 . , 0 2 7 9 3 0 . 0 2 8 5 2 0 . 0 2 6 5 0 10 A4 0 . 0 4 9 0 5 0 , 0 3 6 9 0 0 . . 0 4 0 6 6 0 . 0 5 2 1 5 0 . 0 5 4 2 1 0 . 0 4 6 8 4 11 A5 1 2 1 6 1 3 1 . 0 2 0 8 4 0 . 9 9 6 7 8 1 8 1 184 1 . 3 1 4 3 1 1. 2 4 9 9 5 12 A6 0 . . 6 3 9 0 7 0 . 5 3 0 9 6 0 . . 6 7 8 6 4 0 . 9 4 4 4 3 0 . 7 5 8 9 2 0 . 7 0 8 2 9 13 B1 0 0 1 0 6 0 0 . 0 1 1 3 9 0 . 0 1 2 3 5 0 0 1 2 2 4 0 . 0 1 1 4 2 0 . 01 164 14 B2 0 . 0 1 3 7 0 0 . . 0 1 6 9 9 0 . . 0 2 0 2 6 0 . 0 1 6 6 0 0 0 1 7 2 4 0 . 0 1 7 4 4 15 S 3 0 . 0 2 1 7 5 0 . 0 2 2 7 4 0 . . 0 2 3 9 9 0 . 0 2 1 8 3 0 . 0 2 0 5 8 0 . 0 2 2 2 3 16 B4 0 . . 0 5 2 7 1 0 . 0 4 8 0 7 0 . . 0 5 8 2 7 0 . . 0 8 9 1 4 0 . 0 4 1 8 5 0 . 0 5 6 5 4 17 B5 1 . 9 5 1 3 6 1 . 6 5 0 2 7 2 . 0 9 0 1 6 2 . 7 5 4 3 1 1 . 6 0 5 5 8 1. 9 6 4 9 0 18 B6 0 . 9 5 7 0 3 0 . 8 1 5 4 1 0 . 9 4 3 7 7 1 . 3 7 4 6 5 0 . 8 1 2 1 6 0 . . 9 5 3 8 4 19 C1 0 . 0 1 3 6 1 0 . 0 1 2 4 3 0 . 0 1 2 9 9 0 . 0 1 2 8 5 0 . 0 0 8 7 0 0 . 01 194 2 0 C2 0 . 0 1 9 8 0 0 . 0 1 7 8 1 0 . 0 2 0 2 1 0 . 0 2 2 9 2 0 . 0 1 3 7 0 0 . 0 1 8 4 8 2 1 C3 0 . 0 2 5 9 4 0 . 0 2 4 3 5 0 . 0 2 5 7 7 0 . 0 2 9 4 0 0 . 0 2 138 0 . 0 2 4 8 9 22 C4 0 . 0 6 8 0 6 0 . 0 6 4 0 6 0 . 0 6 5 0 1 0 . 0 5 9 8 0 0 . 0 4 5 9 6 0 . 0 6 0 0 5 23 C 5 2 . 0 6 1 7 3 1 . 7 9 7 2 3 1 . 8 8 0 8 7 1 7 4 8 5 6 I . 6 3 9 0 6 1 8 1472 24 C 6 1 . 7 8 5 4 1 0 . 9 3 6 8 3 1 . 0 2 4 2 5 0 . 8 5 0 2 9 0 . 8 8 2 5 2 1 . 1 0 8 7 5 25 01 0 . 0 2 3 2 8 0 . 0 2 0 1 4 0 . 0 2 0 2 9 0 . 0 1 6 8 9 0 . 0 2 0 8 0 0 , 0 2 0 5 1 2 6 D2 0 . 0 1 9 9 4 0 . 0 2 8 6 0 0 . 0 3 6 9 3 0 . 0 2 7 8 8 0 . 0 3 4 5 5 0 . 0 3 1 4 1 27 0 3 0 . 0 3 1 1 6 0 . 0 4 138 0 . 0 4 3 3 4 0 0 3 3 2 9 0 . 0 4 9 2 5 0 . 0 4 1 9 5 28 D4 0 . 3 8 6 3 9 0 . 2 9 6 7 3 0 . 2 8 3 9 9 0 . 3 4 3 4 3 0 . 2 4 5 1 5 0 . 3 0 2 8 1 2 9 0 5 7 . 2 6 0 8 0 5 . 9 2 2 6 6 5 . 6 8 7 4 5 5 . 7 9 6 2 4 4 . 9 8 0 8 7 5 . 8 4 1 4 0 3 0 D6 2 . 6 6 103 2 . 5 1 1 5 8 2 . 3 7 0 0 5 2 . 3 2 1 5 6 2 . 0 5 6 0 6 2 . 3 6 0 6 7 3 1 E 1 0 . 0 1 2 5 0 0 . 0 1 3 1 5 0 . 0 1 4 9 1 0 . 0 1 2 3 0 0 . 0 0 9 7 6 0 . 0 1 2 6 0 32 E2 0 . 0 2 0 8 9 0 . 0 1 8 4 9 0 . 0 2 3 3 5 0 . 0 1 7 3 7 0 . 0 1 6 7 7 0 . 0 1 9 6 3 33 E 3 0 . 0 2 6 7 8 0 . 0 3 0 0 9 0 . 0 2 8 8 8 0 . 0 2 1 4 1 0 . 0 2 2 5 1 0 . 0 2 6 3 5 34 E4 0 . 0 5 5 7 4 0 . 0 7 2 5 2 0 . 0 9 8 2 8 0 . 1 1 0 2 0 0 . 0 8 3 5 2 0 . 0 8 5 6 8 35 ES 1 . 8 5 3 9 0 2 . 1 9 2 7 3 2 . 7 6 7 3 2 3 . 9 7 5 3 4 2 . 6 8 0 2 2 2 . 7 0 4 7 8 36 E6 0 . 9 5 3 1 0 1 . 0 1 5 6 1 1 . 8 0 4 9 2 2 . 0 4 5 7 4 1 . 3 2 5 2 3 1 . 4 6 7 4 3 ' 1 3 5 ix T.5. V a r i a b l e means, st a n d a r d d e v i a t i o n s , and one way ANOVA F s t a t i s t i c s f o r the f i v e s t o c k s used i n the study by age 3.2 + ( l e a r n i n g samples). GROUP - K I S P I O X COPPER SUSTUT V A R I A B L E 1 PG 1 , OOOOO 0 . . 5 5 5 5 6 0 . 2 5 0 0 0 3 FWA 3 . OOOOO 3 OOOOO 3 . OOOOO 4 SWA 1 . 9 2 5 9 3 1 . 8 1 4 8 1 2 . OOOOO 5 L 8 3 . 0 5 5 5 4 74 . 4 8 5 1 7 7 9 . 3 8 3 3 2 6 WT 6 . 4 7 0 3 7 4 . 0 8 8 8 9 4 . 9 0 8 3 3 7 SEX 1 . . 3 7 0 3 7 1 . 4 4 4 4 4 1 . 3 3 3 3 3 8 A l 0 . . 0 9 0 7 4 0 . . 0 8 9 2 6 0 . 0 8 6 6 7 9 A2 0 . 1 4 4 0 7 0 . . 1 5 1 8 5 0 . 15583 10 A4 0 . . 2 1 3 7 0 0 2 0 0 0 0 0 . 2 3 1 6 7 1 1 A5 6 . 7 4 0 7 4 5 , 8 5 1 8 5 6 . 9 1 6 6 7 12 A6 2 . . 7 7 7 7 8 2 . . 4 4 4 4 4 2 . 8 3 3 3 3 13 B1 0 . 0 4 6 6 7 0 . 0 4 8 1 5 0 . 0 3 4 17 14 B2 0 . 0 9 7 0 4 0 . 0 9 8 5 2 0 . 0 9 1 6 7 15 B 3 0 . 14519 0 . 1 5 1 1 1 0 . 14667 16 B4 0 2 8 4 4 4 0 . . 2 9 0 0 0 0 . 3 0 1 6 7 17 B 5 11 . 2 9 6 3 0 11 6 6 6 6 7 1 2 . OOOOO 18 B6 5 . . 7 0 3 7 0 5 . 6 6 6 6 7 5 . 7 5 0 0 0 19 C1 O , 0 5 1 4 8 0 . 0 5 0 7 4 0 . 0 4 4 17 2 0 C2 0 . 1 0 8 8 9 0 . . 1 0 4 0 7 0 . 1 1000 21 C3 0 . 1 6 6 3 0 0 . 1 6 0 3 7 0 . 16750 22 C4 0 . 3 2 5 5 6 0 . 3 3 3 3 3 0 . 3 0 7 5 0 23 C 5 11 . 8 5 1 8 5 12 . 2 5 9 2 6 1 0 . 9 1 6 6 7 24 C6 5 . 6 2 9 6 3 5 . . 8 5 1 8 5 5 . 16667 25 01 0 . 0 8 2 9 6 0 . 0 8 4 4 4 0 . 0 6 5 8 3 26 0 2 0 . 1 7 8 5 2 0 . 1 7 5 1 9 0 . 1 6 5 0 0 27 0 3 0 . 2 8 6 3 0 0 . 2 7 1 4 8 0 . 2 6 6 6 7 28 0 4 1 . 6 9 9 6 3 1 . 6 9 5 5 5 1 . 4 7 0 0 0 29 D5 37 . 2 2 2 2 1 35 . 1 4 8 1 5 3 0 . 7 5 0 0 0 3 0 D6 16 . 4 4 4 4 4 15 . 5 9 2 5 9 14 . 9 1 6 6 7 COUNTS 2 7 . 2 7 . 12 . F TO BABINE MORICE A L L G P S . ENTER DF = 4 136 0 . 2 9 0 9 1 0 6 0 0 0 0 0 . 5 1 7 7 3 2 758 3 OOOOO 3 . OOOOO 3 . OOOOO 0 . 0 1 . 9 4 5 4 5 1 . 4 0 0 0 0 1 . 8 4 3 9 7 12 . 5 4 7 77 . 28 18 1 63 . 7 2 4 9 9 76 . 10779 16 . 5 4 3 •4 . . 5 8 7 2 7 2 . 4 5 0 0 0 4 . 5 7 6 6 0 24 . 7 5 0 1 . 3 8 1 8 2 1 . 4 5 0 0 0 1 . 397 16 0 . 2 0 0 0 . 0 9 4 0 0 0 . 10150 0 . 0 9 2 9 1 1 . 259 0 . 1 5 0 1 8 0 1 6 7 0 0 0 . 15220 2 . 3 1 8 0 2 3 0 7 3 0 . 2 5 9 0 0 0 . 22567 3 . 978 7 . 3 4 5 4 5 8 . 2 0 0 0 0 7 . 0 2 8 3 7 5 . 227 3 . . 0 9 0 9 1 3 . 4 5 O 0 0 2 . 936 17 3 . 4 2 0 0 . 0 4 9 2 7 0 . .04 ISO 0 . 0 4 6 17 4 . 6 0 5 0 . 1 0 5 4 5 0 . . 0 8 9 5 0 0 . 0 9 9 0 8 3 . 2 7 7 0 16018 0 . . 1 4 0 0 0 0 . 15156 3 . 4 6 0 0 . 3 4 5 0 9 0 . 2 4 8 5 0 0 . 3 0 5 5 3 6 . 6 4 1 13 . 2 3 6 3 6 10 5 5 0 0 0 12 . 0 7 8 0 1 5 153 6 . 2 5 4 5 5 4 . 7 0 0 0 0 5 . 7 7 3 0 5 4 . 956 0 . . 0 5 3 2 7 0 . 0 4 0 0 0 0 . 0 4 9 7 9 5 9 1 2 0 . 1 1 6 3 6 0 . 0 9 2 0 0 0 . 10858 a . 7 5 8 0 , 1 7 8 3 6 0 . 1 4 7 0 0 0 . 16723 6 7 8 0 0 . 3 8 9 0 9 0 . 2 8 7 5 0 0 . 3 4 4 8 9 5 . 6 8 5 14 . 1 2 7 2 7 10 . 9 0 0 0 0 12 . 6 0 2 8 4 8 . 223 6 . 6 0 0 0 0 5 .OOOOO 5 . 92 199 7 878 0 . 0 8 5 0 9 0 . 0 8 1 0 0 0 . 0 8 2 3 4 2 8 18 0 . 19145 0 . 1 7 7 0 0 0 . 18 156 2 602 0 . 3 0 6 18 0 . 2 8 5 5 0 0 . 2 8 9 4 3 4 . 0 7 5 1 . 7 9 0 5 4 1 . 6 7 3 5 0 1. 71106= 2 . 6 7 8 34 . 8 7 2 7 3 34 . 2 0 0 0 0 34 . 9 2 9 0 8 3 . 06 1 16 . 0 3 6 3 6 15 . 6 5 0 0 0 15. 8 7 9 4 3 1 . 217 5 5 . 2 0 . 14 1. STANDARD D E V I A T I O N S GROUP V A R I A B L E PG FWA SWA L WT SEX 8 A1 9 A2 10 A4 1 1 A5 12 A6 13 B1 14 B2 15 B3 16 B4 17 B5 18 B6 19 C I 2 0 C2 21 C3 22 C4 23 C5 24 C6 25 DI 26 D2 27 D3 28 0 4 29 D5 3 0 0 6 K I S P I O X 1 . 3 8 6 7 5 0 . 0 0 . 2 6 6 8 8 9 . 4 5 0 8 5 2 . 0 3 3 3 4 0 . 4 9 2 1 0 0 . 0 2 0 9 3 0 . 0 2 3 5 8 0 . 0 5 1 9 7 2 . 0 4 9 2 5 1 . 0 1 2 7 4 0 . 0 1 1 4 4 0 1 5 4 0 0 2 4 8 6 0 6 6 0 6 0 7 2 0 6 1 3 7 3 0 0 1 2 9 2 0 1 3 4 0 0 2 5 8 9 0 8 5 6 8 . 9 3 1 3 1 . 4 4 5 1 0 . 0 1 7 7 2 . 0 2 6 7 0 0 . 0 3 9 0 4 0 . 3 6 3 7 8 5 . 0 4 8 4 7 2 . 2 5 8 8 8 COPPER SUSTUT 1. 0 5 0 0 3 0 . 6 2 1 5 8 0 . 6 8 5 1 0 0 . 9 4 0 3 2 0 . 9 5 8 9 4 0 . 0 0 . 0 0 . O 0 . 0 0 . 0 0 . 3 9 5 8 5 0 . 0 0 . 2 2 9 1 8 0 . 5 0 2 6 2 0 . 3 1 5 7 9 9 . 5 5 8 7 9 5 . 3 9 4 9 1 7 . 0 5 6 9 6 9 . 8 4 2 8 0 8 . 3 7 8 8 3 1 . 6 1 8 9 6 t . 0 1 2 1 6 1 . 0 4 0 8 4 1 . 0 8 8 4 5 1 . 4 0 3 5 7 0 . 5 0 6 3 7 0 . 4 9 2 3 7 0 . 4 9 0 3 1 0 . 5 1 0 4 2 0 . 4 9 6 7 6 0 . 0 2 4 6 4 0 . 0 2 3 0 9 0 . 02 122 0 . 0 2 3 0 0 0 . 0 2 2 2 6 0 . 0 2 4 3 4 0 . 0 3 1 7 5 0 . 0 2 5 3 5 0 . 0 3 2 7 8 0 . 0 2 6 5 8 0 . 0 3 7 7 2 0 . 0 6 0 4 3 0 . 0 5 0 3 6 0 . 0 7 4 8 3 0 . O S 3 6 0 1 . 2 9 2 1 0 1. 9 2 8 6 5 1. 6 8 0 1 5 2 . 5 8 7 4 2 1 . 8 6 5 2 0 0 . 6 4 0 5 1 0 . 9 3 7 4 4 0 . 948 15 1 . 5 0 3 5 0 1 . 0 0 9 13 0 , . 0 1 2 1 0 0 . 0 1 5 0 5 0 0 1 2 3 0 0 . 0 1 2 2 6 0 . 0 1 2 3 4 0 . 0 1 8 9 5 0 . 0 2 3 6 8 0 . 0 1 8 5 4 0 . 0 2 3 0 5 0 . 0 1 9 2 4 0 . 0 2 1 9 0 0 . 0 3 0 8 5 0 . 0 2 3 6 1 0 . 0 2 4 0 6 0 . 0 2 4 2 7 0 . 0 6 1 3 9 0 . 0 7 3 7 1 0 . 0 9 9 3 7 0 . 0 5 8 5 1 0 . 0 7 9 9 6 2 . 4 1 7 8 8 3 . 4 9 0 2 4 2 . 8 7 3 6 5 2 . 18788 2 . 6 2 1 3 2 1 3 8 6 7 5 1 . 7 1 2 2 5 1 , 4 3 0 0 7 1 . 0 8 0 9 3 1 . 3 5 1 7 8 0 . . 0 1 2 0 7 0 . .01 164 0 . 0 1 1 2 3 0 . 0 0 7 9 5 0 . 01 139 0 . 0 2 0 8 0 0 . 0 1 1 2 8 0 . 0 1 6 7 1 0 . 0 1 4 7 3 0 0 1 6 3 8 0 . 0 2 8 4 8 0 . 0 1 4 8 5 0 . 0 2 5 0 7 0 . 0 1 8 9 5 0 0 2 4 5 1 0 . 0 9 0 0 4 0 , 0 7 5 6 9 0 . 1 1263 0 . 0 6 0 3 4 0 . 0 9 4 6 7 3 . 1 0 8 2 1 2 . 9 0 6 3 7 2 . 5 9 6 6 7 1 . 6 8 2 7 3 2 . 6 9 1 7 7 1 . 4 0 6 1 3 1 . 4 0 3 4 6 1 . 2 1 1 0 6 0 . 9 1 7 6 6 1 . 2 7 9 2 7 0 . 0 2 3 7 5 0 . 0 1 9 7 5 0 . 0 1 6 2 0 0 . 0 1 6 5 1 0 . 0 1 8 4 9 0 . 0 3 8 1 7 0 . 0 2 5 0 5 0 . 0 3 1 2 3 0 . 0 3 2 7 8 0 . 0 3 1 6 7 0 . 0 5 0 1 3 0 . 0 3 1 4 3 0 . 0 4 0 3 9 0 . 0 5 3 3 6 0 . 0 4 3 5 6 0 . 2 7 3 0 1 0 . 3 6 4 4 9 0 . 2 7 2 8 8 0 . 3 9 0 0 1 0 . 3 1 7 9 8 5 . 5 5 1 8 7 5 . 9 7 1 5 2 5 . 1 8 5 6 3 6 . 2 0 3 5 6 5 . 4 5 0 0 5 2 . 2 5 7 6 2 1 . 9 7 5 2 2 2 . 3 0 1 0 7 2 . 1 3 4 3 1 2 . 2 3 7 0 0 136 ix T.6. V a r i a b l e means, standard d e v i a t i o n s , and one way ANOVA F s t a t i s t i c s for the f i v e stocks used in the study by age 4.2 + ( l e a r n i n g samples). MEANS F TO GROUP K I S P I O X COPPER SUSTUT BABINE MORICE ALL G P S . ENTER V A R I A B L E DF = 4 18! 1 PG 0 . 4 4 4 4 4 0 . 3 2 5 5 8 0 . 3 3 8 9 8 0 . 2 3 0 7 7 0 . 2 6 9 2 3 0 . 3 3 1 5 8 0 . 296 3 FWA 4 OOOOO 4 .OOOOO 4 . 0 1 6 9 5 4 OOOOO 4 . 0 3 8 4 6 4 . 0 1 0 5 3 0 . 8 1 7 4 SWA 2 . 6 9 4 4 4 2 . 7 4 4 1 9 2 . 3 8 9 8 3 2 . 0 3 8 4 6 2 . 4 6 1 5 4 2 . 4 8 9 4 7 4 . 0 2 1 S L 8 5 . 4 9 1 6 5 79 . 0 1 1 6 1 83 . 3 8 9 8 2 74 . 3 9 6 1 5 76 . 2 1 9 2 2 8 0 . 5 8 5 2 5 12 . 366 6 WT 6 . 8 7 2 2 2 4 . 8 5 1 16 5 . 9 4 9 15 4 . 1 3 0 7 7 4 . 1 2 6 9 2 5 . 3 7 7 3 7 19 . 6 2 2 B A1 0 . 0 9 4 1 7 0 . 0 9 6 5 1 0 . 0 9 2 2 0 0 . 1 0 0 3 8 0 . 0 9 6 5 4 0 . 0 9 5 2 6 0 . 7 2 3 9 A2 0 . 1 4 5 8 3 0 . 1 5 1 6 3 0 . 1 5 5 5 9 0 . 1 5 2 6 9 0 . 1 5 6 9 2 0 . 1 5 2 6 3 1 . 0 0 4 10 A4 0 . 1 8 2 2 2 0 . 1 8 6 5 1 0 . 2 1 1 3 6 0 . 2 2 8 8 5 0 . 2 2 7 3 1 0 . 2 0 4 7 9 7 . 4 0 8 1 1 A5 5 . 4 7 2 2 2 . 5 . 3 2 5 5 8 6 . 1 5 2 5 4 7 . 5 3 8 4 6 7 . 0 7 6 9 2 6 . 1 5 2 6 3 18 . 963 12 A6 2 . 3 6 1 11 2 . 0 9 3 0 2 2 . 5 2 5 4 2 3 .OOOOO 2 . 8 0 7 6 9 2 . 5 0 0 0 0 8 . 0 4 4 13 B1 0 . 0 4 3 6 1 0 . 0 4 8 3 7 0 . 0 4 305 0 . 0 4 6 9 2 0 . 0 4 0 7 7 0 . 0 4 4 5 8 2 . 567 14 B2 0 . 0 9 0 8 3 0 . 1 0 0 2 3 0 . 1 0 2 2 0 0 0 9 7 6 9 0 . 0 8 9 2 3 0 . 0 9 7 2 1 3 . 9 9 0 15 B3 0 . 1 3 7 5 0 0 . . 15209 0 . 1 6 0 6 8 0 14885 0 . 1 3 5 7 7 0 14932 8 529 16 B4 0 . 2 4 2 2 2 0 . 2 4 4 4 2 0 . 2 7 3 3 9 0 . 2 7 3 4 6 0 2 2 2 6 9 0 . 2 5 4 0 0 4 , 753 17 B5 10. . 4 7 2 2 2 9 . . 4 4 1 8 6 9 . 8 9 8 3 0 10. 9 6 1 5 4 9 . 8 0 7 6 9 10. . 0 3 6 8 4 2 . 759 18 B6 5 OOOOO 4 . 3 9 5 3 5 4 72881 5 . 1 1538 4 . 5 7 6 9 2 4 . 73684 2 . 9 4 5 19 C1 0 . 0 4 6 3 9 0 . 0 4 9 5 3 0 0 4 3 7 3 0 . 0 4 8 4 6 0 . 0 4 3 8 5 0 . 0 4 6 2 1 1 , 835 2 0 C2 0 . 10417 0 . 10512 0 . . 1 0 9 4 9 0 . 1 0 5 0 0 0 . 0 9 5 3 8 0 . 10495 2 . 47 1 21 C3 0 . 15917 0 . 16256 0 . 17339 0 . 15846 0 . 14577 0 . 16242 6 19 1 22 C4 0 . 2 7 5 2 8 0 . 2 8 1 1 6 0 . 2 9 7 9 7 0 . 2 7 7 3 1 0 . 2 4 8 8 5 0 . 28032 2 934 23 CS 1 0 . 2 2 2 2 2 1 0 . 3 9 5 3 5 10 . 2 5 4 2 4 10 . 7 6 9 2 3 9 . 8 8 4 6 1 10. 3OOO0 0 . 7 9 0 24 C6 5 . 11111 4. 8 8 3 7 2 4 . 9 4 9 1 5 5 . 0 7 6 9 2 4 . 6 5 3 8 5 4 . 9 4 2 1 0 0 . 703 25 01 0 . 0 7 9 1 7 0 . 0 8 3 9 5 0 . 0 7 2 3 7 0 . 0 9 0 0 0 0 . 0 7 0 0 0 0 . 0 7 8 3 7 5 . 288 26 0 2 0 . 17556 0 . 181 16 0 . 17339 0 . 19962 0 . 16654 0 . 17821 4 . 728 27 0 3 0 . 2 9 0 8 3 0 . 2 9 0 7 0 0 . 2 7 6 6 1 0 . 3 1846 0 . 27 192 0 . 2 8 7 5 8 6 . 0 3 1 28 0 4 1 . 8 4 7 7 8 1 . 7 7 5 8 1 1 . 6 3 0 3 4 1 . 796 15 1. 7 0 3 4 6 1. 737 16 3 . 182 29 0 5 3 7 . 9 1 6 6 6 3 6 . 0 6 9 7 6 3 2 . 7 7 9 6 5 35 6 5 3 8 4 3 5 . 6 1 5 3 7 3 5 . 2 7 8 9 5 4 . 463 3 0 D6 1 6 . 5 2 7 7 7 1 5 . 9 0 6 9 8 1 5 . 6 2 7 1 2 I S . 8 0 7 6 9 15 . 7 6 9 2 3 15 . 9 0 5 2 6 0 . 807 31 E1 0 . 0 5 2 5 0 0 . 0 5 2 5 6 0 . 0 4 9 8 3 0 . 0 5 1 5 4 0 . 0 4 4 2 3 0 . 0 5 0 4 2 2 . 0 6 6 32 E2 0 . 1 1 194 0 . 10721 0 . 12220 0 . 1 1385 0 . 0 9 6 5 4 0 . 1 122 1 8 . 0 5 9 33 E 3 0 . 16778 0 . 16442 0 . 19068 0 . 17500 0 . 14923 0 . 17258 12 . 139 34 E4 0 . 2 7 5 5 6 0 . 3 0 9 0 7 0 . 3 7 2 2 0 0 . 34 192 0 . 2 6 8 4 6 0 . 3 2 1 2 6 1 1 . 249 35 E 5 9 . 6 6 6 6 7 1 0 . 7 2 0 9 3 12 . 1 1864 1 1 . 7 3077 1 1 . OOOOO 1 1 . 13158 5 . 262 36 E6 4 . 6 1 1 1 1 4 . 8 1 3 9 5 5 . 8 1 3 5 6 5 . 5 3 8 4 6 5 . 15385 5 . 2 3 1 5 8 4 . 9 8 3 COUNTS 3 6 . 43 . 5 9 . 26 . 2 6 . 1 9 0 . STANDARD D E V I A T I O N S GROUP K I S P I O X COPPER SUSTUT BABINE MORICE A L L G P S . V A R I A B L E 8 3 5 9 5 1 PG 0 . 9 6 9 3 7 0 . 8 0 8 3 2 0 . 8 8 2 9 8 0 . 5 8 7 0 4 0 . 7 7 7 5 7 0 . 3 FWA 0 . 0 0 . 0 0 . 13019 0 . 0 0 . 19612 0 . 10252 4 SWA 0 . 8 2 1 B 2 1 . 1 1468 0 . 6 1 6 3 5 0 . 19612 0 . 8 5 9 3 4 0 . 7962 1 5 L 9 . 8 9 3 4 9 6 . 10534 8 . 4 0 3 6 8 3 . 7 6 8 4 3 7 . 7 7 5 2 9 7 . 6 9 4 7 3 6 WT 2 . 0 0 4 9 4 1 . 3 0 1 9 0 1 . 8 0 4 5 3 0 . 6 8 3 9 7 1 . 2 9 2 3 0 1 . 5 6 6 8 5 8 A1 0 . 0 2 5 1 1 0 . 0 2 0 8 0 0 . 0 2 0 0 9 0 . 0 2 2 5 4 0 0 2 2 2 6 0 . 02 190 9 A2 . 0 . 0 2 6 2 3 0 . 0 2 6 0 0 0 . 0 2 4 3 0 0 . 0 2 8 7 8 0 0 2 6 19 0 0 2 5 9 5 10 1 1 A4 0 . 0 4 9 7 5 0 . 0 3 8 1 0 0 . 0 4 0 6 6 0 . 0 5 4 5 0 0 . 0 5 6 0 4 0 . 0 4 6 2 8 A5 1 . 2 3 0 2 4 1 . 0 1 7 0 2 0 . 9 9 6 7 8 1 . 8 5 9 6 9 1 38342 1 . 2 4 8 4 5 12 A6 0 . 6 3 9 3 2 0 . 5 2 6 1 7 0 . 6 7 8 6 4 0 . 9 7 9 7 9 0 8 9 5 2 9 0 . 7 2 2 9 2 13 B 1 0 . 0 1 0 7 3 0 . 0 1 1 1 1 0 0 1 2 3 5 0 . 01 192 0 . 0 0 8 9 1 0 . 0 1 1 3 0 14 B2 0 . 0 1 3 8 1 0 . 0 1 7 3 9 0 0 2 0 2 6 0 . 0 1 7 0 4 0 . . 0 1 7 19 0 , 0 1 7 6 8 15 8 3 0 . 02 196 0 . 0 2 3 15 0 . 0 2 3 9 9 0 . 0 2 1 4 2 0 02 194 0 0 2 2 8 1 16 B4 0 . 0 5 3 1 9 0 . 0 4 8 9 6 0 0 5 8 2 7 0 0 8 9 7 1 0 0 4 4 2 3 0 . , 0 5 9 1 2 17 B5 1 . 9 6 3 7 6 1 . 7 0 8 5 5 2. 0 9 0 1 6 2 . 8 6 3 2 9 1, 6 4 9 7 1 2. , 0 5 8 5 4 18 B6 0 . . 9 5 6 1 8 0 . 8 4 9 0 7 0 . 9 4 3 7 7 1 . 4 2 3 4 3 0 . 9 4 5 4 3 1 , 0 0 5 2 3 19 C1 0 . 0 1 3 7 6 0 . 0 1 2 3 4 0 . , 0 1 2 9 9 0 . 01 156 0 . . 0 0 8 9 8 0 . 0 1 2 3 4 2 0 C2 0 . . 0 2 0 0 5 0 . 0 1 6 5 3 0 . 0 2 0 2 1 0 . 0 2 3 1 9 0 . 0 1 4 2 1 0 . 0 1 9 1 3 21 C3 0 . , 0 2 6 1 2 0 . . 0 2 1 2 8 0 . 0 2 5 7 7 0 . 0 2 8 8 0 0 . 0 2 0 6 2 0 . 0 2 4 6 9 22 C4 0 . 0 6 7 5 5 0 . . 0 6 2 7 2 0 . 0 6 5 0 1 0 . 0 6 2 1 3 0 . 0 4 3 6 6 0 . 0 6 2 1 4 23 C 5 2 . 0 5 7 8 9 1 . 8 0 1 3 1 1 . 8 8 0 8 7 1 . 7 9 5 7 2 1 . 6 8 1 12 1 . 8 6 1 3 3 24 C6 1 . 8 0 1 2 3 0 .93119 1 . 0 2 4 2 5 0 . 8 9 0 9 8 0 . 8 9 1 8 4 1 . 1 6 3 7 6 25 DI 0 . 0 2 3 1 0 0 . 0 1 9 6 6 0 . 0 2 0 2 9 0 , 0 1 7 8 9 0 . 0 2 0 4 0 0 . 0 2 0 4 2 26 0 2 0 . 0 2 0 2 1 0 . 0 2 8 2 2 0 . 0 3 6 9 3 0 . 0 2 9 3 2 0 . 0 2 9 9 3 0 . 0 3 0 3 8 27 0 3 0 . 0 3 1 5 7 0 . 0 4 17 1 0 . 0 4 3 3 4 0 . 0 3 3 7 9 0 . 0 4 6 5 6 0 . 0 4 0 2 4 28 D4 0 . 3 8 9 0 4 0 . 2 9 6 2 6 0 . 2 8 3 9 9 0 . 3 5 7 8 7 0 . 2 8 3 0 5 0 . 3 1 9 3 4 2 9 0 5 7 . 3 1 4 8 5 5 . 9 6 5 7 5 5 . 6 8 7 4 5 5 . 9 5 9 4 7 5 . 0 2 0 5 6 6 . 0 4 5 5 7 3 0 D6 2 . 6 6 7 1 1 2 . 5 7 1 0 2 2 . 3 7 0 0 5 2 . 4 1 6 9 3 2 . 0 4 5 6 3 2 . 4 4 1 7 9 31 E 1 0 . 0 1 2 5 1 0 . 0 1 3 1 1 0 . 0 1 4 9 1 0 . 0 1 2 2 3 0 . 0 0 9 0 2 0 . 0 1 3 0 2 32 E2 0 . 0 2 1 0 9 0 . 0 1 9 1 9 0 . 0 2 3 3 5 0 . 0 1 8 1 3 0 . 0 1 5 7 3 0 . 0 2 0 4 1 33 E3 0 . 0 2 7 1 6 0 . 0 3 1 6 5 0 . 0 2 8 8 8 0 . 0 2 2 3 2 0 . 0 2 3 3 1 0 . 0 2 7 7 3 34 E4 0 . 0 5 6 3 9 0 . 0 7 2 4 3 0 . 0 9 8 2 8 0 . 1 1 2 7 5 0 . 0 6 2 9 1 0 . 0 8 4 10 35 E5 1 . 8 6 7 0 1 2 . 1 1 9 3 6 2 . 7 6 7 3 2 4 1042 1 2 . 5 1 3 9 6 2 . 6 8 5 2 2 36 E6 0 . 9 6 4 4 5 0 . 9 8 2 1 2 1 . 8 0 4 9 2 2 . 0 8 2 9 0 1 . 2 2 2 8 6 1 . 4 8 4 8 0 4 13 7 Appendix T.7. Age composition s t r u c t u r e f o r the 1984 commercial f i s h e r y s t e e l h e a d samples. AGE CLASS + + + + + + + + WK SEX 2.1 2.2 3.1 3.2 3.3 4.1 4.2 4.3 RS TOTAL 9 M 2 2 F . 0 0 % .02 .02 10 M 0 1 F 0 0 % - .01 1 1 M 2 2 F 0 0 % .01 .01 12 M 0 0 F 0 2 % - .02 13 M 1 1 F 0 2 % .01 .02 1 4 M 0 5 F 0 2 % • - .06 10 27 6 12 1 20 4 5 .08 .35 .08 .13 7 28 7 8 4 25 4 3 .08 .41 .08 .08 12 25 6 1 1 5 25 1 8 . 13 .37 .05 .14 17 16 6 9 6 25 12 3 . 18 .32 . 14 .09 17 24 1 1 2 2 20 1 4 . 1 5 .34 .09 .05 7 22 9 7 3 1 7 7 2 .08 .33 . 1 4 .08 1 4 6 2 81 1 4 4 4 52 .21 .08 .05 1 10 7 9 77 7 7 3 53 .13 . 1 1 .09 1 15 2 7 82 7 0 6 52 .16 .01 . 10 1 5 3 9 65 9 0 5 62 . 1 1 .02 . 1 1 1 7 7 14 84 6 0 1 1 46 .10 .05 .19 1 10 3 2 65 15 1 6 53 .21 .03 .07 1 TOTALS % .01 .02 .11 .36 .10 .10 .16 .05 .10 1 WEEK KEY: 9 = ending J u l y 21 n= 133 10 = ending J u l y 31 n = 1 30 1 1 = ending Aug. 7 n= 134 1 2 = ending Aug. 1 4 n= 127 13 = ending Aug. 21 n= 130 1 4 = ending Aug. 31 n = 1 18 138 Appendix T.8. Numerical runtiming estimates f o r the f i v e stocks used i n t h i s study through the 1984 commercial f i s h e r y . Model A: smolt age 3/scale v a r i a b l e s alone. Model B smolt age 4/scale v a r i a b l e s alone. Model C pooled smolt age/scale v a r i a b l e s a l o n e . Model D pooled smolt a g e / a l l v a r i a b l e s . 1984 estimated run timing by week model a 9 10 1 1 12 13 1 4 t o t a l stock mor i c e 3670 1 244 1606 2374 1 330 555 10779 babine 210 626 1219 2762 1073 - 5890 sustut 3670 5418 2055 3850 3225 1734 19952 zymoetz - 44 1 - - - 257 698 k i s p i o x 525 - 573 - 948 - 2046 by p r o p o r t i o n mor i c e .340 .115 . 149 .220 . 123 .052 1 .00 babi ne .036 . 106 .207 .469 .182 - 1 .00 sustut . 1 8 4 .272 . 103 .193 .162 .087 1 .00 zymoetz - .632 - - - .368 1 .00 k i s p i o x .257 - .280 - .463 - 1 .00 model D 9 10 1 1 12 13 14 t o t a l stock mor i c e 1707 1064 492 - 394 375 4032 babine 787 532 - 687 - 83 2089 sustut 2003 1812 1066 1 032 1289 751 7953 zymoetz 1223 - 1721 1 1 46 693 334 5117 k i s p i o x 1001 1 169 - 687 495 3352 by p r o p o r t i o n morice .423 .263 . 122 - - - 1 .00 babine .376 .254 - .329 - .040 1 .00 sustut .252 .228 . 134 . 130 .162 .094 1 .00 zymoetz .239 - .336 .224 .135 .065 1 .00 ki s p i o x .299 .349 - .205 . 1 48 - 1 .00 model c 9 10 1 1 1 2 13 1 4 t o t a l stock morice 5164 3035 1749 2067 1 277 683 1 3975 babine 885 1232 1267 2372 1920 552 8228 sustut 6368 6171 3793 5353 4 1 90 261 4 28489 zymoetz 551 846 776 1 229 426 340 4168 k i spiox 1537 1 1 32 1329 1751 1627 303 7679 by p r o p o r t i o n morice .369 .217 . 125 . 147 .091 .049 1 .00 babine .107 .150 . 1 54 .288 .233 .067 1 .00 sustut .224 .217 . 133 .188 .147 .092 1 .00 zymoetz . 1 32 .203 .186 .294 .102 .082 1 .00 k i s p i o x .200 .147 .173 .228 .212 .039 1 .00 model d 9 10 1 1 12 13 14 t o t a l stock morice 8689 5213 5401 1459 1850 528 23140 babine 1436 2090 1 134 3641 1941 340 10582 sustut 4395 5126 4609 4262 3319 2573 24284 zymoetz . - - 390 3324 644 491 4849 k i s p i o x - - 634 - 1306 - • 1940 by p r o p o r t i o n 1 .00 morice .375 .225 .233 .063 .080 .023 babine .136 .198 .107 .344 .183 .032 1.00 sustut .181 .211 .189 .176 .137 .106 1 .00 zymoetz - .080 .685 .133 .101 1 .00 k i s p i o x - - .327 - .673 — 1 .00

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