Fish loss and movement in irrigation diversions from the West Gallatin River, Montana by William D Clothier A THESIS Submitted to the Graduate Faculty in partial fulfillment of the requirements for the degree of Master of Science in Fish and Wildlife Management Montana State University © Copyright by William D Clothier (1952) Abstract: Fish loss and movement in irrigation diversions from the West Gallatin River, Montana, was investigated during 1950 and 1951. Two-way fish weirs were employed to study fish movement in the Keughen (70.3 cfs) and Low Line (147.5 cfs) Canals. Operation of the weirs was prevented during the spring and fall segments of irrigation seasons by debris-laden water. The Keughen weir operated 6l days in 1950 and 84 days in 1951. A total of 29 trout, 37 whitefish, and 758 non-game fish made up the initial fish movement the first season. There were 55 trout, 77 whitefish, and 767 non-game fish in the initial movement the second season. The Low Line weir operated 41 days in 1951 and had a total of 77 trout, 26 whitefish, and 94 non-game fish showing initial movement during this period. Random movement was shown by all species of fish except cutthroat trout. The up-canal movement of 59 trout was correlated with severe water reductions in the Low Line Canal. This was 88% of all up-canal migrant trout during the 41 days of weir operation. Fish loss (or gain) through the weirs was established by actual counts. Thirteen canals were sampled for fish loss. Game fish concentrations were found near headgates, near creeks where they entered a canal, and in 1 spring-fed ditch. Brook trout was the dominant trout species in the vicinity of creeks and springs. Fish loss did not seem to be correlated with canal length or volume of flow. There was an estimated loss of 2,835 legal game fish (7 or more inches in length) weighing 1,186 pounds in 11 of the canals studied.  rFISH LOSS AND MOVEMENT IN IRRIGATION DIVERSIONS FROM THE WEST GALLATIN RIVER, MONTANA t r j r W illiam D« C lo th ie r A THESIS Subm itted to th e G raduate F acu lty in p a r t i a l f u l f i l lm e n t of th e requ irem en ts f o r th e degree of M aster o f Science in F ish and W ild life Management a t Montana S ta te C ollege Approved: Chapm an, Examining Committee \ JL ^ a n e G raduate ^ x v is io n Bozeman, Montana June, 1902 ' i f , 2Table o f C on ten ts Page A b s tra c t . . . . . . . . . . . . . . . . . . . . . 3 I n t r o d u c t i o n ....................................................................................... 4 Acknowledgments ............................................................................................................... 5 D e sc r ip t io n o f th e West G a l la t in R iv e r in th e s tu d y a re a ................... 5 F ish movement in i r r i g a t i o n c a n a ls ..................................................................... I n i t i a l movement . ............................................................................................ Random movement ................... . . . . . . . . . . . . . . . . . . 13 Movement in r e l a t i o n to tem p e ra tu re and w a te r l e v e l s . . . . 15 F ish lo s s in i r r i g a t i o n c a n a l s .................................................................... 16 Loss d e te rm ined by w e i r s ............................................................................... 19 Loss d e te rm ined by sam pling th e c a n a l s ............................................... 21 E stim a ted l e g a l game f i s h l o s s ....................................................... .... . 28 Summary ................................................................................................................................. L i t e r a tu r e c i t e d ....................... .... ......................................................................... .... * 32 123664 3A b s tra c t F ish lo s s and movement in i r r i g a t i o n d iv e r s io n s from th e West G a l l a t in R iv e r j M ontana, was i n v e s t ig a te d d u rin g 1950 a n d '1951. Two-way- f i s h w e irs were employed to s tu d y f i s h movement in th e Keughen (7.0.3 c f s ) and Low L ine (147 .5 c f s ) C ana ls . O pe ra tion o f th e w e irs was p re v en ted d u r in g th e s p r in g and f a l l segments o f i r r i g a t i o n sea son s by d e b r i s ­ la d en w a te r . The Keughen w e ir o p e ra te d 6 l days in 1950 and 84 days in 1951. A t o t a l o f 29 t r o u t , 37 w h i te f i s h , and 758 non-game f i s h made up th e i n i t i a l f i s h movement th e f i r s t s e a so n . There were 55 t r o u t , 77 w h i te f i s h , and 767 non-game f i s h in th e i n i t i a l movement th e second s e a so n . The Low L ine w e ir o p e ra te d 41 days in 1954 and had a t o t a l o f 77 t r o u t , 26 w h i te f i s h , and 94 non-game f i s h showing i n i t i a l movement d u r in g t h i s p e r io d . Random movement was shown by a l l s p e c ie s o f f i s h ex cep t c u t th r o a t t r o u t . The u p -c a n a l movement o f 59 t r o u t was c o r r e la t e d w ith sev e re w a te r r e d u c t io n s in th e Low L ine C an a l. T h is was 88^ o f a l l u p -c a n a l m ig ran t t r o u t d u rin g th e 41 days o f w e ir o p e ra t io n . F is h lo s s (o r g a in ) th ro ugh th e w e irs was e s ta b l i s h e d by a c tu a l c o u n ts . T h ir te e n c a n a ls were sampled f o r f i s h l o s s . Game f i s h c o n c e n tra t io n s were found n e a r h e a d g a te s , n e a r c re ek s where th e y e n te re d a c a n a l , and in I s p r in g - fed . d i t c h . Brook t r o u t was th e dom inant t r o u t s p e c ie s in th e v i c i n i t y o f c re ek s and s p r in g s . F ish lo s s d id n o t seem to be c o r r e la te d w ith c a n a l le n g th o r volume o f flow . There was an e s t im a te d lo s s o f 2 ,835 l e g a l game f i s h (7 o r more in c h e s in le n g th ) w e igh ing 1 , 186' pounds in 11 o f th e c a n a ls s tu d ie d . 4I n t r o d u c t io n • ' i F ish lo s s in i r r i g a t i o n d iv e r s io n s in Montana was a management i s s u e even "before th e tu rn o f th e c e n tu ry . An a ttem p t was made to p re v en t f i s h lo s s as e a r ly a s 1893 when l e g i s l a t i o n was p a ssed r e q u i r in g s c re e n s to he p la ced in d i tc h e s from September I to March I , d u rin g th e p e r io d o f l i t t l e o r no w a te r u s e . . The law o b v io u s ly had no p r a c t i c a l v a lu e and was re p e a le d in 1897« No f u r t h e r l e g i s l a t i o n con ce rn in g s c re e n s has been e n a c te d s in c e t h a t t im e . An e a r ly t y p i c a l accoun t p la c e d th e lo s s o f f i s h i n th e thou sand s f o r a s in g le c a n a l (Montana F is h and Game D epartm en t, 1904) . P e r io d ic p le a s f o r c o n tro l m easures s t im u la te d in v e s t ig a t io n s o f s c re e n in g d ev ic e s by th e S ta te F is h and Game D epartm en t. A few o f th e e x p e r im en ta l i n s t a l ­ l a t i o n s were c o n s id e re d s u c c e s s f u l , b u t in 1942 th e . D epartm ent r e p o r te d t h a t annual m ain tenance f o r a s ta tew id e s c re e n in g program would c o s t th r e e tim es as much money as was a v a i l a b le f o r th e o p e ra t io n s o f th e e n t i r e F i s h e r ie s D iv is io n (Montana F is h and Game D epartm ent, 1942 ). While p a s t work in Montana was d i r e c te d tow ard c o n t r o l , l i t t l e q u a n t i t a t i v e in fo rm a tio n has been secu red ^n th e a c tu a l- lo s s o r th e f a c to r s a f f e c t i n g i t . Answers to i n q u i r i e s in d ic a te th e same u n so lv ed problem e x i s t s in o th e r w este rn s t a t e s and p ro v in c e s o f Canada h av ing a s e r io u s lo s s o f n o n -m ig ra to ry f i s h in i r r i g a t i o n d iv e r s io n s . D ata f o r th e p re s e n t s tu d y o f f i s h lo s s and movement in i r r i g a t i o n d iv e r s io n s were c o l l e c te d d u rin g th e 1950 and 1951 i r r i g a t i o n season s (June to O c to b e r ) . O b se rv a tio n s were co n fin ed to th e d iv e r s io n s o f th e West G a l la t in R iv e r , G a l la t in County , Montana, 5Acknowledgments The w r i t e r e x ten d s th ank s to D r. 0 . J . D. Brown who d i r e c te d th e p roblem and a s s i s t e d i n p re p a r in g th e m an u sc r ip t . 'The Montana F ish and Game Departm ent fu rn is h e d c o n s id e ra b le tim e o f f i e l d p e r s o n n e l , gave f i n a n c i a l a s s is ta n c e and c o n tr ib u te d w e ir m a te r i a l s . Mr. John S p in d le r and Mr. George H o lton gave v a lu a b le f i e l d a s s i s t a n c e . The h e lp o f Mr. B i l l Papke, E iv e r Comm issioner, in s e c u r in g in fo rm a tio n on th e v a r io u s c a n a ls i s g r a t e f u l l y a p p re c ia te d . Thanks a re a ls o due th e U n ited S ta te s F ish and W ild l i f e S e rv ic e , M isso u ri E iv e r B asin S tu d ie s , and th e fa rm e rs and ra n c h e rs o f G a l l a t in V a lley f o r t h e i r coope ra tion ." D e s c r ip t io n o f th e West G a l la t in E iv e r in th e s tu d y a re a The s e c t io n o f th e West G a l l a t in E iy e r unde r o b s e rv a tio n ( a p p ro x i­ m a te ly 20 m ile s ) e x ten d s from n e a r th e mouth o f G a l l a t in Canyon to 1300 f e e t downstream from I rw in B rid g e . The s tream emerges from th e canyon a t abou t 5000 f e e t e le v a t io n and flow s n o r th th ro ugh th e w est s id e o f G a l l a t in V a lle y , I t s g r a d ie n t i s ap p ro x im a te ly 34 f e e t p e r m ile . Maximum channe l w id th i s I 50 f e e t , and th e average i s n e a r 70 f e e t . I n s e v e r a l p la c e s th e s tream flow i s d iv id e d i n to two o r more ch ann e ls as i t p a s s e s th ro u g h th e r e l a t i v e l y narrow f lo o d p l a in (a p p ro x im a te ly 200 to 500 y a rd s w id e ) . P oo ls a re s l i g h t l y l e s s abundant th a n r i f f l e s . Bottom m a te r ia ls a re p redom in an tly ru b b le and g ra v e l and s tream banks a re g en e ro u s ly covered by sh rub s and cottonwood t r e e s . T rou t p ro d u c tio n i s good. I n ­ te n s iv e c r e e l census in th e s tu d y a re a d is c lo s e d an average r a t e o f c a tc h p e r f ish e rm an hou r o f 0 .57 ( 0 .36 o f a pound) in 1949 and 0 .51 (0 .3 5 o f a 6pound) in 1950 (M issou ri R iv e r B asin S tu d ie s , 1951)• A t o t a l o f 52 d iv e r s io n c a n a ls o r ig in a te w ith in th e s tu d y s e c t io n . They range in s i z e from I to 268 s e c o n d - fe e t (d e c re ed r i g h t ) and i r r i g a t e app ro x im a te ly 90 ,000 a c r e s , ETone o f th e d iv e r s io n s i s s c re e n ed . Each y e a r some o f th e West G a l la t in R iv e r "below Irw in B ridge i s s u b je c t to v a ry in g d eg rees o f d ry in g -u p from d ew a te rin g p r a c t i c e s , P oo ls become warm and s ta g n a n t and i t i s n o t u n u su a l f o r many f i s h to d i e . In 1950 abou t 2 m ile s o f th e West G a l la t in R iv e r in t h i s a re a was l o s t due to de­ w a te r in g . The a v e ra g e ”d iv e r te d flow o f ,822 s e c o n d - fe e t (d is c o u n tin g r e tu r n flow s) v a r ie d from 1620 on June 5 ? to 387 on September 15. From 1930 to 1945 th e av e rag e annual r i v e r flow was 682 s e c o n d - fe e t , A minimum annu a l flow o f 533 s e c o n d - fe e t was re c o rd ed f o r th e w a te r y e a r (O c tober I to September 30) 1940-41 , and a maximum annual flow o f 956 s e c o n d - fe e t o c cu r re d d u rin g th e w a te r y e a r 1947-48 (M issou ri R iv e r B asin S tu d ie s , 1951 ). S pec ies o f f i s h found in th e s tu d y a re a were ra inbow t r o u t ( Salmo g a i r d n e r i i ) , brown t r o u t (Salmo t r u t t a ) , c u t th r o a t t r o u t (Salmo c l a r k i i ) , e a s te r n b rook t r o u t ( S a lv e lin u s f o n t i n a l i s ) , m ountain w h i te f is h (Rrosopium w il l iam s o n i) , longnose s u c k e r , (Catostomus c a to s tom u s ) , w h ite s u ck e r (Catostomus commersonnii) , s o u lp in (C o ttu s p u n c tu la tu s b a i r d i i ) , 1 and longnose dace (R h in ich th y s c a t a r a c t a e ) . ETumerous ra inbow -cu t th r o a t h y b r id s were p r e s e n t , b u t f o r p u rpo se s o f t h i s s tu d y th e y were c l a s s i f i e d a s ra inbow o r c u t t h r o a t , depending on which t r a i t was dom inan t, 7F ish movement in i r r i g a t i o n c a n a ls A two-way f i s h w e ir , m od if ied from a d e s ig n d e s c r ib e d by S h e t te r (1 9 38 ) , was i n s t a l l e d in th e Keughen Canal in th e s p r in g o f I 950 and a n o th e r o f s im i la r d e s ig n was p la c e d in th e Low L ine Canal in th e s p r in g o f 1951 f o r th e pu rpo se o f s e c u r in g in fo rm a tio n on th e e f f e c t o f w a te r tem p e ra tu re and f l u c tu a t i o n on d a i ly and se a so n a l movement o f f i s h . , The in ta k e s o f th e s e two c a n a ls a re app ro x im a te ly o n e -q u a r te r m ile a p a r t on th e same s id e o f th e r i v e r (F ig . l ) . The Keughen Canal i s o f medium s iz e (7 0 .3 c f s ) and th e Low L ine (147«5 c f s ) i s la rg e in com parison w ith o th e r c a n a ls o f th e a r e a . Each o f th e s e d i tc h e s had a r e p u ta t io n f o r ta k in g many f i s h . An e f f o r t was made to p re v e n t f i s h lo s s in th e Keughen Canal by lo c a l spo rtsm en in 1935• They i n s t a l l e d a s t a t i o n a r y - b a r type s c re e n w ith a padd le w heel s c r a p e r , b u t t h i s d ev ice r e q u ir e d so much m ain tenance t h a t i t was removed in 1936. The Keughen Canal f i s h w e ir (F ig , 2) was p la c e d 200 f e e t b eh ind th e h e adg a te in o rd e r n o t to: r e t a r d th e flow a t th e i n ta k e . The main arm o f th e w e ir c o n s is te d o f a g r id w ith -fr-inch o p en in g s . T h is was e f f e c t iv e in ta k in g f i s h over 5 in c h e s in t o t a l l e n g th . The Low L ine Canal f i s h w e ir (F ig . 2) was p la c e d I 60 f e e t b eh in d th e h e ad g a te , and i t s g r id had open ings o f -g to 3 /4 in c h e s . T h is sp ac in g s topped most o f th e f i s h over 7 in c h e s in t o t a l le n g th . The f i s h c a p tu re d each day were weighed to th e n e a r e s t 0 .01 o f a pound, and t h e i r t o t a l le n g th s were ta k en to th e n e a r e s t 0 .1 o f an in c h . Each f i s h was f i n c l ip p e d and a llow ed to co n tin u e in th e d i r e c t io n it-:w as g o in g when c a u g h t. 8A< I V P ig . I . A 20-m ile s e c t io n o f th e West G a l la t in E iv e r showing th e 13 can a ls s tu d ie d . 9D ete rm in a tio n o f f i s h lo s s f o r whole i r r i g a t i o n season s was n o t po s­ s i b l e because d e b r is c a r r i e d by s p r in g r u n - o f f d e lay ed w e ir o p e ra t io n s 4 to 7 w eeks, and o p e ra t io n s had to be d is c o n t in u e d abou t 4 weeks e a r ly each f a l l because o f l e a v e s . The Keughen w e ir was o p e ra te d 6 l days in 1950— J u ly 27 to September 26, and 84 days in 1951—June 28 to September 19 . The Low L ine i n s t a l l a t i o n was m a in ta in ed 41 days from J u ly 18 u n t i l th e c a n a l was tu rn e d o f f August 27, 1951. .. D a ily maximum and minimum w a te r tem p e ra tu re s were ta k en a t th e Keughen f i s h w e ir . The w a te r tem p e ra tu re s a t t h i s s t a t i o n were i d e n t i c a l w ith th o se ta k en a t th e Low L ine w e ir and in th e r i v e r a t th e c an a l i n ­ t a k e s , Canal w a te r l e v e l s were re c o rd e d d a i ly , A gage was m a in ta in ed d u r in g th e . 1951 sea son in th e West G a l la t in E iv e r n e a r th e w e ir s i t e s . I n i t i a l movement Two groups o f f i s h a re c o n s id e re d in r e l a t i o n to movement—th o se I /w hich were a lr e a d y in th e c an a l when th e t r a p was i n s t a l l e d (u p -can a l m ig ra n ts ) and th o se which came down th e c an a l su b sequen t to i t s i n s t a l l a ­ t i o n (down-canal m ig r a n ts ) . The t o t a l number o f i n i t i a l down-canal m i­ g r a n ts in th e Keughen Canal d u r in g th e 6 l-d a y t r a p o p e ra t io n in 1950 was 502 , and th e i n i t i a l number o f u p -c a n a l m ig ran ts was 322 , During th e 84'-' day p e r io d o f 1951> 546 f i s h showed i n i t i a l down-canal movement and 353 i n i t i a l u p -c a n a l movement ( t a b le l ) . There were 24 down-canal t r o u t m ig ra n ts tak en th e f i r s t s e a so n , and 14 o r 5 8 . 3$ o f th e s e were c u t t h r o a t . T h is was n o t to be expec ted s in c e c u t th r o a t com prised l e s s th an 2$ o f a l l t r o u t re co rd ed in th e 1950 c r e e l cen su s f o r th e a d ja c e n t s e c t io n o f th e 10 Fig* 2 , A. Kerughen Canal f i s h w e ir . B. Low L ine Canal f i s h w eir 11 West G a l la t in H iv e r (M issou ri R iv e r B asin S tu d ie s , 1951)• In th e second sea so n 38 t r o u t moved down th e c an a l w ith "brook t r o u t (13) and ra inbow t r o u t (12) p red om in a tin g . There were on ly 5 u p -c a n a l t r o u t m ig ran ts in 1950 a s compared to 17 in 1951• Every t r o u t s p e c ie s was re p re s e n te d in t h i s u p -c a n a l movement excep t c u t t h r o a t , T rou t com prised 3 .5$ o f th e 824 i n i t i a l m ig ran ts th e f i r s t y e a r and 6 .1$ o f 899 th e second y e a r , W h ite f ish were a ls o tak en more f r e q u e n t ly th e second y e a r . They numbered 77 o r 8 .6 $ o f th e t o t a l i n i t i a l movement in 1951 a s compared to 37 (4 .5 $ ) in 1950 . Suckers showed a g r e a te r movement th an any o th e r s p e c ie s , b u t t h e i r t o t a l number d e c re a se d from 374 th e f i r s t season to 338 th e second se a so n . About 1$ o f th e s e were w h ite su ck e rs and th e r e s t were lo n gno se . S cu lp in s made up a s u b s t a n t i a l number o f th e i n i t i a l f i s h movement. T h e ir g r e a te s t abundance was re a ch ed in 1951 when 171 e n te re d th e u p -c a n a l t r a p . Dace were r e l a t i v e l y abundant b o th y e a r s . They com prised 14 .6$ o f th e t o t a l i n i t i a l movement in 1950 compared to 12 .9$ in 1951 . Only a few la r g e f i s h were ta k en in th e Keughen Canal ( t a b le l ) , One brown t r o u t in 1950 and 2 in 1951 were over 17 in c h e s in t o t a l le n g th . S ix o f th e w h i te f i s h c a p tu red exceeded 10 in ch e s in t o t a l le n g th . There were few su ck e rs o f in te rm e d ia te s i z e (9 to 16 in c h e s ) . Most o f th e specim ens tak en were l e s s th an 9 in c h e s in le n g th . I n i t i a l movement in th e Low L ine Canal d u rin g th e 41 days o f o b se rv a ­ t i o n in 1951 c o n s is te d o f 65 down- and 132 u p -c a n a l m ig ran ts ( t a b le 2 ) . Of th e s e 197 f i s h , 39 .1$ were t r o u t , 13 .2$ were w h i te f i s h , and 31 .5$ were 12 Tab le I . I n i t i a l f i s h movement in th e Keughen Canal J u ly 27 to September 26, 1950 Length in in c h e s Movement P e rc en tag e movement ( t o t a l movement) S p ec ie s down HE down HE ' t o t a l average range Rainbow 5 0 1 .0 0 .0 0 .6 6 .2 4 * 6— 8 .4 C u tth ro a t 14 0 2 .8 0 .0 1 .7 7 .8 5 .9 -1 0 .0 Brook 3 ■ 3 0 .6 0 .9 0 .7 7 .0 2 .5 - 8 .4 Brown 2 2 0 .4 0 .6 0 .5 2 .6 -1 8 .7 W h ite f is h 33 4 6 .6 1 .3 ,4 .5 4 .2 2 .6 -1 3 .7 Suckers 209 165 4 1 .6 51 .3 45 .4 5 .3 2 .6 -1 7 .7 S cu lp in s 156 108 31 .1 33.5 32 .0 3 .1 2 .0 - 5 .0 Dace 80 40 15 .9 12 .4 14 .6 3 .8 2 . 4 - 518 T o ta l 502 322 100 .0 100.0 100 .0 June 28 to September 19, 1951 Rainbow 12 7 2 .2 2 .0 2 .1 5 .7 2 .4 -1 4 .5 C u tth ro a t 5 0 0 .9 0 .0 0 .6 8 .5 5 . 9 - n . o Brook 13 5 2 .4 1 .4 2 .0 5 .1 2 . 4 - 9 .6 Brown 8 5 1 .5 1 .4 1 .4 . 6 .5 2 . 7- 18 .3 W h ite f is h 63 14 11 .5 4 .0 8 .6 3 .8 2 . 5- 12 .3 Suckers 211 127 38.6 36 .0 37 .6 5 .9 2 .3 -1 7 .4 S cu lp in s I 42 171 26 .0 48 .4 34 .8 3 .3 2 . 0 - 5 .1 Dace , _22 -2 4 16 .9 6 .8 1 2 .9 . 3 .9 2 . 5 - 6 .2 T o ta l 546 353 100 .0 100.0 100 .0 T ab le 2 . I n i t i a l f i s h movement in th e Low L ine C ana l, J u ly 18 to August 27 , 1951 Length in in c h e s Movement P e rc en tag e movement ( t o t a l movement) S p ec ie s down HE down HE t o t a l . average range Rainbow I 33 1 .5 25 .O 17 .3 11 .3 7 .0 -1 8 .5 C u tth ro a t 4 I 6 .2 0 .8 2 .5 7 .3 5 .1 - 8 .6 Brook 0 9 0 .0 6 .8 4 .6 9 .5 5 .5 -1 2 .9 Brown 5 24 7 .7 18 .2 14 .7 10 .2 6 . 9^20 .0 W h ite f is h 9 17 13 .8 12 .9 13 .2 10 .8 4 .0 -1 5 .9 Suckers 37 25 56 .9 18 .9 31 .5 7-9 5 .9 -1 8 .2 S cu lp in s 7 13 10 .8 9 .8 10 .1 3 .6 3 .0 - 4 .3 Dace 2 10 3 .1 7 .6 6 .1 5 .3 4 .7 - 5 .7 T o ta l 65 132 100 .0 100.0 100 .0 13 s u c k e r s . Only IO t r o u t moved down th e c an a l compared to an i n i t i a l u p - c a n a l movement o f 67 . Suckers a g a in showed more i n i t i a l movement th an any o th e r s p e c ie s . The two l a r g e s t t r o u t tak en in th e Low L ine Canal in c lu d ed a brown t r o u t (20 in c h e s , 3 .53 pounds) and a ra inbow t r o u t (18 .5 in c h e s , 2 .02 p ound s). An a d d i t io n a l 6 t r o u t and 5 w h i te f is h exceeded I pound e ach . The l a r g e s t w h i te f i s h was 1 .70 pounds. Only I su ck e r l a r g e r th an 9*7 in c h e s was ta k e n . Random movement In 1950 a l l down-canal m ig ran t t r o u t in th e Keughen Canal rem ained down, and a l l b u t I (b rook t r o u t ) o f th e u p -c a n a l m ig ran ts rem ained up . Of th e t r o u t c a p tu re d in t h i s d i t c h th e second y e a r , I down-canal ra inbow m ig ran t came back up and r e tu rn e d down a second tim e , and I u p -c a n a l mi­ g r a n t o f t h i s same s p e c ie s r e tu rn e d down. The random movement f o r b rook t r o u t was e x a c t ly th e same as t h a t f o r ra inbow . Ebne o f th e 1951 down- c a n a l brown t r o u t m ig ra n ts r e tu rn e d to th e r i v e r , b u t o f th e u p -c a n a l m ig ra n ts , I went back down and s ta y e d . There was no random w h i te f i s h movement ob served th e f i r s t y e a r , b u t in 1951? 3 down-canal w h i te f i s h m ig ran ts c i r c l e d back and down th e c an a l a second tim e . T h reeno f th e u p -c a n a l w h i te f i s h m ig ran ts went back down and s ta y e d . There were 4 d ow n -can a l'm ig ran t su ck e rs in 1950 th a t cam e'back up and th e n moved down a second tim e , w h ile 103 o f th e u p -c a n a l su ck e r m ig ran ts went back down. S ix ' o f th e s e moved up th e c an a l a second tim e b u t o n ly I 14 o f them s ta y e d . A t o t a l o f 19 down-canal su ck e r m ig ran ts in 1951 moved hack up on ly to r e tu r n down a second t im e , and 2 o f th e s e came hack up a g a in and r e tu rn e d down a t h i r d t im e . The number o f u p -c a n a l su ck e r mi­ g r a n ts t h a t went hack down th e second y e a r was 10-5, and o f th e s e 3 came up and re tu rn e d down a g a in . Only I down-canal s c u lp in m ig ran t moved hack up and th e n down th e c an a l d u r in g th e f i r s t s e a so n . A t o t a l o f 21 u p -c a n a l m ig ra n ts o f t h i s s p e c ie s wfemt hack down, and 3 o f th e s e came hack out and s ta y e d . F ive o f th e down-canal m ig ran ts th e second y e a r r e tu rn e d hack ou t o f th e c a n a l . There were 28 u p -c a n a l m ig ran ts which re tu rn e d down. Two o f th e se made a second round t r i p th ro ugh th e t r a p s . Of th e dace t h a t were observed to move down th e Keughen Canal in 1950, 6 made a complete c i r c l e hack th ro ugh th e t r a p s . E ig h t o f th e u p - c an a l m ig ran ts moved hack down, and I o f th e se moved up and re tu rn e d down th e c an a l a second tim e . There were 17 down-canal dace m ig ran ts in 1951 th a t moved up and th e n re tu rn e d down th e c a n a l . Four o f th e s e made s t i l l a n o th e r round t r i p th ro ugh th e t r a p s . Only 5 o f th e u p -c a n a l m ig ran ts showed random movement hack down th e c a n a l . One o f th e s e moved up a second tim e and s ta y e d . Of a l l i n i t i a l down-canal m ig ran ts in th e Low L ine C ana l, I brown t r o u t and 7 su ck e rs came hack up and s ta y e d . The u p -c a n a l m ig ran ts which re tu rn e d hack down th e c an a l in c lu d e d one each o f ra inbow t r o u t , brown t r o u t , and w h i te f i s h . The brown t r o u t came hack up a second tim e and s ta y e d . 15 Movement i n r e l a t i o n to tem p e ra tu re and w a te r l e v e l s The most c o n c e n tra te d down-canal movement o f t r o u t and w h i te f is h in th e Keughen Canal o c cu rred b o th y e a rs d u r in g th e t h i r d week in Septem ber. Mean w eekly w a te r tem p e ra tu re s f o r th e s e p e r io d s (4 8 . 4 ° and 49 - I 0F) were th e low est re a ch ed w h ile th e t r a p was i n o p e ra t io n . The tem pe ra tu re d e c l in e in each case was a s s o c ia te d w ith r a in y w ea th e r . Huntsman (1945) d e s c r ib e d f r e s h e t s as a s t im u la n t to th e movement o f c e r t a i n salm onids and o th e r f i s h . D uring th e p e r io d August 2 -8 , 1951» tw ice as many t r o u t and w h i te f i s h ( 14 ) moved down th e Keughen Canal th an were c ap tu red in th e p re v io u s 5 w eeks. T h is in c re a s e d movement fo llow ed a day o f heavy p r e c i ­ p i t a t i o n ( P .9 9 ' o f an i n c h ) . However, th e re was no marked in c re a s e in t r o u t o r w h i te f i s h movement fo llow in g 2 days o f r a in o f in te rm e d ia te i n ­ t e n s i t y (0 .5 4 and O.58 o f an in ch ) which o c cu rred 3 weeks l a t e r . The 59 su ck e rs t h a t moved up th e Keughen Canal d u r in g th e f i r s t 5 weeks o f t r a p o p e ra t io n ( J u ly 27 to August 30) in 1950 was about tw ice th e down-canal number. Doym-can a l su ck e r m ig ran ts f o r th e week August 31 t o September ,6' t o t a l e d 9 5 5 which was 5 tim e s g r e a te r th a n f o r any p rev io u s week. U p -cana l numbers in c r e a s e d , b u t to a l e s s e r d e g re e . The mean w a te r tem p e ra tu re t h i s week ( 58 .7 °F ) was th e h ig h e s t re c o rd ed f o r th e e n t i r e s tu d y p e r io d . Sucker movement in th e second y e a r cou ld n o t be c o r r e la te d w ith warm o r coo l p e r io d s . More su ck e rs moved.down th e c an a l d u r in g th e day th a n a t n ig h t in th e week o f h ig h e s t mean w a te r tem p e ra tu re . There were 50 d ay -tim e m ig ran ts as compared to 23 n ig h t m ig ran ts in a 3 -day p e r io d . Ho d ay -tim e u p -c a n a l movement o c cu rred on th e s e d ay s . W ith t h e ' e x c e p tio n o f t h i s p e r io d , on ly 16 I an o c c a s io n a l f i s h o f any s p e c ie s was ta k en in th e t r a p s d u r in g th e day­ tim e . S cu lp in movement in c re a s e d h o th sea son s a f t e r th e end o f August. Minimum dace movement c o in c id ed w ith low w a te r tem p e ra tu re s . Those ta k en betw een June 28 and J u ly 21 c a r r ie d spawning c o lo rs and s e v e r a l were r i p e . P ish movements in th e Keughen Canal were h o t ob served to be a f f e c te d by w a te r r e d u c t io n s , bu t i n th e Low L ine Canal a d i r e c t c o r r e la t io n e x i s t e d betw een sev e re w a te r f l u c tu a t io n s and t r o u t movement up stream (F ig . 3 ) . A t o t a l o f 43 t r o u t moved in to th e u p -c a n a l t r a p in th e 3 days fo llow in g a w a te r r e d u c t io n o f 41 c f s (August 2 ) . The volume o f flow was d e c re a se d to about o n e -q u a r te r o f th e c an a l c a p a c ity a t t h i s t im e . On August 16 th e flow was reduced by 39 c f s , and 13 more t r o u t moved up t h e . c a n a l . Only 3 t r o u t moved up fo llow in g th e l a s t r e d u c tio n (49 c fs ) on August 24 . The 59 t r o u t which came ou t fo llow in g th e s e re d u c tio n s c o n s t i ­ tu t e d 88$ o f a l l u p -c a n a l m ig ran t t r o u t f o r th e sea so n . T rou t s iz e as w e ll as numbers d e c re a se d w ith each su cceed in g cu t in w a te r volume. T h e ir average w eigh t f o r th e 3 r e d u c t io n s b eg in n in g w ith th e f i r s t was 0 .6 6 , 0 .5 3 and 0 .19 pounds. The r i v e r w a te r l e v e l n e a r th e w e ir s i t e s underw ent a n a tu r a l d rop o f 3 .5 in ch e s d u r in g th e 1951 o b s e rv a tio n p e r io d . T h is sh rin k ag e d id n o t cause a m easu rab le f i s h movement ou t o f th e r i v e r in to th e c a n a ls . F ish lo s s in i r r i g a t i o n c an a ls F ish lo s s was i n v e s t ig a te d in 13 o f th e 52 i r r i g a t i o n c an a ls in th e s tu d y a re a (F ig . l ) . Loss th ro ugh th e Keughen and Low L ine w e irs was N U M BE R O F Fl -120---------VOLUW OF FLOW -------- TROUT -------- WMlTEFIRM ------- SUCKERS : \ _ _ _ JULY AUGUST F ig . 3 . Movement o f t r o u t , w h ite f ish and suckers up th e Low Line Canal fo llow ing w ater reductions V O LU M E O F FL O W 18 e s ta b l i s h e d by a c tu a l c o u n ts . Shocking supplem ented by p o iso n in g and g e n e ra l o b s e rv a tio n s was employed in s ta l l 13 c a n a ls , in c lu d in g th e 2 w ith ■ w e ir s . I n te n s iv e sam pling began i n m id -Ju ly , 1951, a f t e r th e volume o f flow in th e c a n a ls was reduced to d e c reed r i g h t . These re d u c tio n s amounted to about o n e -h a lf o f th e c an a l c a p a c i ty in some in s ta n c e s . I t was im p r a c t ic a l to a ttem p t sam pling e a r l i e r in th e season when th e can a l banks were f u l l . The f i s h , t h e r e f o r e , had an o p p o r tu n i ty to e n te r th e c a n a ls ap p ro x im a te ly one month b e fo re sam pling began . Samples were ta k en l a t e r in th e season in 6 c a n a ls a f t e r th e y were tu rn e d o f f . A 1 2 5 -v o l t , 250 -w att d i r e c t - c u r r e n t g e n e r a to r was g e n e r a l ly u sed for. sh o ck in g , b u t on 5 o c c a s io n s a 2 4 0 -v o l t , 500-w a tt a l t e r n a t in g - c u r r e n t machine was employed. H o lton (1952 found th e d i r e c t - c u r r e n t g e n e ra to r 97$ e f f i c i e n t in ta k in g f i s h 3*5 in c h e s and lo n g e r in t o t a l le n g th from a s p r in g - f e d c re ek in th e a re a ( maximum flow 14.7 c f s ) . I n i r r i g a t i o n d i tc h e s t h i s equipment was n o t alw ays e f f e c t iv e in ta k in g f i s h l e s s th a n 7 in c h e s in le n g th . I t was n o t u sed in th e l a r g e r d i tc h e s when th e y were c a r ry in g a head o f w a te r . The d i f f e r e n c e in e f f i c i e n c y betw een d i tc h e s was u ndoub ted ly due to t h e i r h ig h ly v a r ia b le w id th s , d e p th s , and v e lo c i ­ t i e s . S e c tio n s sampled were u s u a l ly 300 f e e t in le n g th f o r a c t iv e c a n a ls . Each s e c t io n was b lo cked a t th e ends w ith n e ts and shocked u n t i l no more game f i s h cou ld be ta k e n . In c a n a ls which were tu rn e d o f f ( i n a c t i v e ) , s e c t io n le n g th s v a r ie d from HO to 7 ,260 f e e t . D e r r is ro o t (ro ten o n e ) was u sed to d e te rm ine f i s h lo s s e s in p a r t s o f th e High L ine and G ilm ore- Todd C anals fo llow in g h eadga te c lo s u r e . • One s e c t io n was e s t a b l i s h e d n e a r th e h eadga te on each c an a l s tu d ie d . 19 O ther sample a re a s were chosen to r e p r e s e n t a l l re g io n s o f a can a l i n s o f a r a s a c c e s s i b i l i t y would p e rm it . U nb iased s e le c t io n a t each p o in t o f a c c e ss was s t r i v e d f o r by sam pling th e f i r s t p o r t io n o f th e c an a l app roached . Some sp o t sam pling was done in a re a s l i k e l y to have c o n c e n tra t io n s o f game f i s h . A ll s e c t io n s ex cep t th o se o f in a c t iv e c a n a ls c o n ta in in g c l e a r , sh a llow w a te r were sampled by sh o ck in g , D e r r is ro o t was employed in th e sh a llow a re a s where a s l i g h t c u r re n t e x i s t e d . O ther sh a llow (o r d ry ) s e c t io n s were c a r e f u l ly c anv a ssed . Of th e t o t a l fo o ta g e covered in th e c a n a ls which were tu rn e d o f f , sho ck ing comprised 53*4%, p o iso n in g 28 .5$ and c an v a ss in g 1 8 .1 $ , S ix 3 0 0 -fo o t s t r a t i f i e d random s e c t io n s were e s t a b l i s h e d by random numbers ( Sned e co r , 1946) in th e Farm ers Canal a t a tim e when i t c a r r ie d 37 .5 c f s o f w a te r . These were in a d d i t io n to two s e c t io n s (n o t random) s e le c te d in th e u pp e r one m ile o f th e c a n a l. A ll t r o u t and w h i te f i s h c a p tu red were coun ted , weighed and m easured . S c u lp in s , dace and su ck e rs were coun ted , bu t on ly a r e p r e s e n ta t iv e sample was w eighed . Loss d e te rm in ed by w e irs The. f i s h lo s s d e te rm in ed by means o f th e w e irs does n o t in c lu d e s p r in g and f a l l segments o f th e i r r i g a t i o n s season s when d e b r is - la d e n w a te r p re v en ted t r a p o p e ra t io n . Net lo s s (numbers and pounds) f o r each t r a p o p e ra t io n p e r io d i s th e t o t a l perm anent u p -c a n a l numbers o f th e v a r io u s f i s h s p e c ie s l e s s t h e i r t o t a l i n i t i a l down-canal numbers. Net g a in i s g iv en in numbers and pounds when more f i s h came ou t th a n went down th ro ugh th e w e ir s . 20 There was a n e t lo s s o f 20 t r o u t ( 5 .56 pounds) th ro u gh th e Keughen Canal w e ir in 1950 and 24 t r o u t (3 .5 0 pounds) in 1951 ( t a b l e 3) . W hite - f i s h com prised 9 . 4# o f th e t o t a l n e t number l o s t th e f i r s t y e a r ( l l . 4 $ o f th e poundage compared to 15 . 5$ th e second y e a r (4 .1 $ o f th e poundage) . Non-game s p e c ie s made up 84 . 1$ o f th e number and 68 .6$ o f th e w eigh t lo s s in 1950; and 77 .4$ o f th e number and 77 .9$ o f th e w eigh t i n 1951. A n e t g a in o f 57 t r o u t (3 8 .1 0 pounds) and 7 w h i te f i s h ( 8 .51 pounds) r e tu rn e d to th e r i v e r from th e Low L ine Canal d u r in g th e season ( ta b le . 4 ) • There was a n e t lo s s o f 5 su ck e rs (0 .0 9 o f a pound) th ro ugh th e Low L ine w e ir . T ab le 3 . F ish lo s s in th e Keughen Canal a s de te rm ined by w e ir J u ly 27 to September 16 , 1950 Down ( lo s s ) Up (g a in ) Net lo s s w eigh t w eight w eigh t Spec ie s number (pounds) number ( pounds) number (pounds) Eainbow 5 0 .45 0 0 .00 5 0 .4 5 C u tth ro a t 14 2 .16 0 0 .00 14 2 .16 Brook 3 0 .5 3 ' 2 0 .20 I 0 .3 3 Brown 2 2 .64 2 0 .02 0 2 .62 W h ite f ish 33 3 .23 4 0 .04 29 3 .19 Suckers 209 19 .83 . 63 2 .78 146 17 .05 S cu lp in s 156 2 .16 90 1 .08 66 1 .08 Dace 80 1.57 . .3 2 0 .57 _j|8 1 .00 T o ta l 502 32.57 193 4 .69 309 27 .88 June 28 to September 19, 1951 Eainbow 12 1.86 6 0 .05 6 1 .81 C u tth ro a t 5 1,17 0 0 .00 5 1 .17 Brook 13 1 .36 4 0 .0 4 9 1 .32 Brown 8 1 .83 4 2 .63 4 (0 .8 0 ) W h ite f ish 63 1 .45 11 0 .48 52 • 0 .97 Suckers 211 18.86 ■ 22 2 .04 I 89 16.82 S cu lp in s 142 2 .46 148 2 .15 (6 ) 0 .3 1 Dace -2 2 2 .61 20 O.52 -7 2 • 2 .09 T o ta l 546 31.60 215 7 .91 . 331 23^69 Table 4» KLsh lo s s in th e Low L ine C ana l, J u ly 18 to August 27 , 1951, a s d e te rm in ed by w e ir Down ( l o s s ) Up (g a in ) Net ' 21 Spec ie s number w eigh t ( pounds) number w eigh t ( pounds) number w eigh t ( pounds) Eainbow I 0 .12 32 19.60 31 / 19 .48 / C u tth ro a t 4 0 .49 I 0 .20 3 - 0 .2 9 - Brook O 0 .00 9 3.36 9 / 3 .36 / Brown 5 0 .75 25 16.30 20 / 15 .55 / W h ite f ish 9 3 .3 1 . 16 11.82 7 / 8 .51 / Suckers 37 6.97 32 6 .88 5 - 0 .09 - S cu lp in s 7 0 .16 13 0 .22 6 / 0 .0 6 / Dace _2 0 .09 10 0 .43 _8 / 0 .3 4 / Tot a l 65 11.89 138 58.81 73 / 46 .92 / Loss d e te rm in ed by sam pling th e c a n a ls There i s a g r e a t d e a l o f d i v e r s i t y in th e p h y s ic a l c h a r a c t e r i s t i c s o f th e c a n a ls s tu d ie d and i n th e numbers o f f i s h each a t t r a c t e d . T h is was re c o g n iz e d by Wales (1948) who re p o r te d t h a t some c a n a ls ta k e few non- m ig ra to ry t r o u t . The immediate a re a b eh ind c an a l h e ad g a te s i s ch a rac ­ t e r i z e d by maximum flow , c l e a r w a te r , and o f te n p o o ls . P ro g re ss in g , down th e c a n a ls flow i s reduced by w ithd raw a l f o r i r r i g a t i o n and t u r b i d i t i e s g e n e r a l ly in c re a s e a s a r e s u l t o f r e tu r n flow and o th e r f a c t o r s . The g r e a t e s t number o f f i s h was found in th e u pp e r o n e -q u a r te r to o n e -h a lf m ile o f c an a l ex cep t in th r e e d i tc h e s where f i s h c o n c e n tra t io n s were a s s o c ia te d w ith s p r in g - f e d a re a s o r c re ek s e n te r in g th e ch ann e l. A few c an a ls have two h e ad g a te s— one a t th e p o in t o f d iv e r s io n from th e r i v e r and th e o th e r some d is ta n c e down th e c a n a l . The downstream h eadga te i s u sed to r e g u la te \h e flow in to th e c an a l p ro p e r . Here s u rp lu s w a te r i s b y -p a ssed back to th e r i v e r . Water was p e rm it te d to flow a l l y e a r in th e a re a between th e two h e ad g a te s o f th e Low L ine C analj b u t in th e Keughen, High Line and 22 Farm ers C anals t h i s a re a i s m os tly d ry a f t e r th e c a n a ls a re tu rn e d o f f i n th e f a l l . The a re a between th e h e adg a te s was shocked a f t e r h eadga te c lo su re in th e Keughen Canal in 1950 and Farmers Canal i n 1951« There were T l t r o u t (1 2 .3 1 pounds) and 22 w h i te f i s h (0 .9 4 o f a pound) ta k en from th e 4 0 0 -fo o t s e c t io n o f th e Keughen C ana l. These f i s h comprised 13,2% o f th e number and 7 2 .2 ^ o f th e w eigh t o f a l l t r o u t and w h i te f i s h c a p tu red i n th e e n t i r e > . ' c a n a l , e x c lu s iv e o f w e i r s . Two 3 0 0 -fo o t s e c t io n s o f th e most fa v o ra b le h a b i t a t betw een h e ad g a te s in th e Farm ers Canal were sam pled . T h is r e p r e ­ s e n te d app rox im a te ly o n e - f i f t h o f th e a r e a . The 504 t r o u t ( 88 .4 pounds) and 120 w h i te f i s h (2 .6 pounds) c ap tu red made up 9 2 . 9% o f th e t o t a l number a n d .84.7% o f th e w eigh t o f a l l game f i s h ta k en in th e c a n a l . F ish observed in th e Low Line Canal a f t e r i t was tu rn e d o f f were p re ­ dom inan tly sm a ll . A pp a ren tly most o f th e la rg e t r o u t had moved out th ro u gh th e w e ir d u r in g e a r l i e r w a te r r e d u c t io n s . In th e 5?165 f e e t sam pled , on ly 21 t r o u t ra n g in g from 7 to 13 in ch e s were ta k e n . The average le n g th f o r th e 405 t r o u t c a p tu re d was 3«4 in c h e s . A ll w h i te f is h were l e s s th a n 5 in c h e s in le n g th . A pprox im ate ly I 64O l i n e a l f e e t o f c an a l was shocked in . th e f i r s t o n e -h a lf m ile beh ind th e h e ad g a te . About 96% o f th e t r o u t and w h i te f i s h were ta k e n i n t h i s a r e a , which was ch a rac ­ t e r i z e d by a s e r i e s o f p o o ls . C on sid e rab le v a r i a t i o n was shown betw een th e y e a r s o f 1950 and 1951 i n th e pounds o f game f i s h ta k en from th e High L ine Canal ( t a b l e 5 )• Sampling th e f i r s t y e a r was l im i te d t o one 1245 -foo t s e c t io n imm ed ia te ly b eh ind th e down-canal h e a d g a te . T h is a re a y ie ld e d 18 t r o u t (1 3 .7 pounds) Table j?o C anals sampled9 numbers and w eigh ts o f game f i s h Oaptnred9. and e stim ated numbers and w eigh ts o f le g a l game f i s h rO Name of c an a l Fl ow d ec re ed ri g h t (c fs ) L en gt h of ca na l (m il es ) M on th a nd ye ar s am pl ed N um be r of se ct io ns s am pl e' Pe rc en ta ge o f le ng th s am pl ed U S I sm Po is on q I la C an va ss in g Game f i s h Trout No. Lb- cap tu red W hite fish No. Lb Estim ated le g a l game f i s h lo s s No. Ib Farmers " 268.0 10.1* 8 -9 /51 16 9 .0 Ii5IliO 1,000 51*7 io it.66 125 2.76 537 21*2 KLeinschmidt 151.0 19 .0 9/51 10 5 .5 3,1*28 2,110 305 103.36 185 3.7b 560 277 High Line li t? . 5 30.3 9 /50 I 0 .8 1,21*5 18 13.78 90 2.60 8/51 13 6 .8 2 ,876 6,060 1,885 9 1.91* 6 1.-60 61 23 Low Line 11*7.5 31 .6 8 /5 l 7 ■ 3=1 .3 ,2 6 5 1,900 1*05 12.11 1*62 9 .21 132 71 Keughen 70.3 9 .9 8 -9 /50 6 I*. I* 2,310 89 ‘ Ut= 90 38 3=1*1*. 167 W* 7/51 3 2 .2 1,160 9 1.91* 6 2.71* Beck and Border 5o .o 7 .6 8 -9 /51 8 21*. 0 9,610 235 93.13 22 1.27 368 176 Moreland 1*8.0 H*. I* 7 /5 l 3 1 .5 1 ,160 9 6.96 8 5.97 Heeb-Buffin — — 7 /5 l I* 705 61 26.10 25 2.71 Creamery 20.0 2 .5 7 /51 3 . 8 .7 1,150 8 2.95 I 0=10 1*1* 33 A llis o n - , Lewis 18=0 3 .3 9 /51 6 10.3 1,800 11*5 28.95 0 0 .00 851 289 C lark 16 .0 3 .7 9 /51 3 5*6 1,100 126 10.30 0 0 .00 77 20 Gilmore—Todd lit . 9 2 .0 7/51 I .1*5.5 it, 800 12 2.60 la 0.21 22 6 C o ck r i l l 5 .9 7 .2 8/51 6 I*. 7 1,800 11 2.21 -13 0 .26 16 T o ta l 90 - 35s7U9 10,860 6 , 8 # 1989 k2$.89 1022 36.61 2835 1186 24 and 90 w h i te f i s h (2 .6 pounds) . Only 9 t r o u t (1 .9 4 pounds) and 6 w h i te f i s h ( l .60 pounds) were ta k en in over 2 m ile s o f s e c t io n s sampled in 1951 . A lthough th e re were j u s t two 3 0 0 -fo o t s e c t io n s shocked imm ed ia te ly b eh ind th e h eadga te th e second y e a r , i t i s p ro b ab le t h a t th e v a r i a t i o n was due to h eadga te m an ip u la tio n . I n 1950 th e h eadga te was c lo sed t i g h t l y w ith ou t g iv in g f i s h an o p p o r tu n i ty to r e tu r n to th e r i v e r a f t e r th e y had been s t im u la te d by reduced f low , w hereas in 1951 flow had been reduced to ap p ro x im a te ly 7 cfs. a few days b e fo re sho ck in g . Few game f i s h were, found in th e G ilmore-Todd and C o c k r i l l .D itch es ( t a b l e 5 ) . They were th e sm a l le s t d i tc h e s sampled. A t o t a l o f 4800 f e e t o f th e G ilmore-Todd D itch a d ja c e n t and downstream from th e h eadga te was p o iso n ed . Twelve t r o u t and 41 f i n g e r l i n g w h i te f is h were ta k en from t h i s a r e a . They were w id e ly d i s t r i b u t e d . The s ix 300 -fo o t s e c t io n s shocked in th e C o c k r i l l D itch y ie ld e d 11 t r o u t and 13 f i n g e r l i n g w h i te f i s h . There were no t r o u t found beyond th e f i r s t o n e -q u a r te r m ile below th e h e ad g a te . The l a r g e s t t r o u t ta k en from e i t h e r d i t c h was an 1 1 -in ch ra inbow . C reeks e n te r e d 3 o f th e c a n a ls s tu d ie d (F ig . l ) . I n th e se in s ta n c e s w a te r was u s u a l ly r e le a s e d from th e c an a l o p p o s ite th e p o in t o f c reek e n tra n c e in o rd e r to m a in ta in a flow in th e c re ek below . Brook t r o u t were dom inant and o f te n abundant in th e c a n a ls n e a r c re e k s . The average le n g th o f a l l brook t r o u t ta k en in th e v i c i n i t y o f c re ek s was over 9 in c h e s . One brook t r o u t m easured 18 .2 in ch e s in le n g th and weighed 3 .02 pounds. The g r e a t e s t c o n c e n tra t io n s o f b rook t r o u t in th e c an a ls were found d u rin g th e spawning se a so n . On September 29 in th e K le in schm id t C ana l, 138 b rook t r o u t (5 4 .6 1 pounds) were found in a 3 2 0 -fo o t s e c t io n 25 around th e e n tra n c e p o in t o f W ilson G reek. In th e same c an a l and on th e same d a te 6,6 b rook t r o u t and I ra inbow t r o u t ( t o t a l w eigh t 35.67' pounds) were ta k en from a 2 5 2 -fo o t s e c t io n lo c a te d app rox im a te ly 3 .5 m ile s helow th e p la c e where Cottonwood C reek e n te r s th e c a n a l . The Beck and B order C ana l, which i s b is e c te d by and r e c e iv e s much o f i t s w a te r from H y a li te C reek , c o n ta in ed 192 t r o u t (8 0 .3 pounds) in a 7 260 -fo o t s e c t io n b eg in n in g app ro x im a te ly 2 m ile s below th e p la c e o f b i s e c t io n . These f i s h had en­ t e r e d th e c an a l b e fo re September 23 arid were b lo cked by an 8 - fo o t f a l l s from r e tu r n in g to th e c re e k . S p ec ie s com position c o n s is te d o f 147 brook t r o u t (5 5 .7 8 p o und s), 36 ra inbow t r o u t ( 19 .60 p o und s), 8 brown t r o u t (4 .4 8 p o und s), I c u t th r o a t t r o u t (0 .4 4 o f a pound ), and 6 w h i te f i s h (0 .9 3 o f a pound ). A few brook t r o u t were d is b u rs e d around H y a li te Creek in th e Farm ers Canal up to August 30 when th e l a s t samples were ta k e n . Ho brook t r o u t , o r any game f i s h f o r t h a t m a t te r , were found i n th e low er o n e -h a lf o f any la rg e c an a l n o t m od if ied by a c re e k . One 1 6 .1 - in c h w h i te f is h moved down th e High Line. Canal f o r a maximum observed d is ta n c e o f a p p rox im a te ly 15 m ile s . The w a te r in s p r in g - f e d d i tc h e s d u r in g th e n o n - i r r i g a t io n season i s u s u a l ly l o s t th rough seepage a f t e r f low ing a s h o r t d i s t a n c e . However, i t may, as ob served in th e A lliso n -L ew is D itc h , m a in ta in a sm all flow in most o f th e channel a l l y e a r . S ix 3 0 0 -fo o t s e c t io n s o f t h i s d i t c h were shocked in m id-Sep tem ber. The h eadga te was open a t th e tim e to a llow a flow o f 6 .9 otfs. A t o t a l o f 145 t r o u t , in c lu d in g 128 brook t r o u t ( 24 .89 p o und s), 10 brown t r o u t ( l . 4 3 pounds) and 7 ra inbow t r o u t (2 .6 3 p ound s), were ta k en T rou t l e s s th an 7 in c h e s made up 43 .4# o f th e t o t a l number. There were 26 66 .4 pounds o f t r o u t p e r a c re f o r th e combined 6 s e c t io n s . Three f i n g e r - l i n g w h i te f i s h were c a p tu re d . The H eeb-D uffin and Creamery ^ i tc h e s a re lo c a te d n e a r th e dew ate red p o r t io n o f th e West G a l l a t in E iv e r (F ig . l ) . There i s no h eadga te on th e H eeb -D uffin D itch and flow in to i t s in ta k e c ea se s when th e r i v e r re a ch e s a low l e v e l . W ater from a n o th e r d i t c h e n te r s th e H eeb -D uffin 5P0 f e e t b eh in d i t s in t a k e , th u s m a in ta in in g flow over much o f i t s cou rse f o r a lo n g e r p e r io d . An i s o l a t e d 3 5 0 -fo o t poo l n e a r th e in ta k e was shocked J u ly 12 . A t o t a l o f 41 t r o u t w e igh ing 20 .46 pounds was ta k e n . Of t h e s e , 34 were brown t r o u t , 4 were ra inbow t r o u t , and 3 were b rook t r o u t . S ix w h i te f i s h w e igh ing 1 .80 pounds were a ls o c a p tu re d . The Creamery D itch had a flow o f 20 c fs a t th e tim e o f sam pling on J u ly 19 -20 . T h is was a lm ost o n e -h a lf o f th e rem a in ing r i v e r flow . Three s e c t io n s were shocked (1150 f e e t ) and th e s e y ie ld e d 6 brown t r o u t , 2 ra inbow t r o u t , and a 7- in c h w h ite - f i s h f o r a t o t a l w eigh t o f 3 .05 pounds. S ev e ra l i r r i g a t e d f i e l d s were in s p e c te d f o r s tra n d e d f i s h , bu t none was found . Many o f th e fa rm e rs in th e a re a i r r i g a t e d by th e G a l la t in c a n a ls were in te rv iew ed in bo th 1950 and 1951* They r e p o r te d v e ry l i t t l e o r no game f i s h movement in to f i e l d s . . The s p e c ie s com position o f a l l 1882 t r o u t ta k en by sam pling in 1951 was 46.1% brook t r o u t , 37 .6 brown t r o u t , 16 . 2% rainbow t r o u t , and 0.1% c u t th r o a t t r o u t . F in g e r l in g t r o u t com prised 54.7% o f th e t o t a l number. About 97.7% o f th e 894 w h i te f i s h were f i n g e r l i n g s , There was a p ro g re s s iv e d e c re a se in th e number o f brown t r o u t and an in c re a s e in brook t r o u t and ra inbow t r o u t in th e c a n a ls go ing from th e low er to th e u pp e r p a r t o f th e 27 s tu d y a re a ( t a b l e 6 ) . S im ila r d i s t r i b u t i o n was found in th e 1949 and 1950 c r e e l census o f th e West G a l la t in E iv e r (M isso u ri E iv e r B as in S tu d ie s , 1951 ). T ab le 6 . The p e rc en ta g e s o f brown t r o u t , b rook t r o u t , and rainbow t r o u t in c an a ls L o ca tio n o f c a n a ls Brown Brook Eainbow Lower (3 ) M iddle (S) Upper (4 ) 82 .7 27 .1 0 .7 5 .2 55.7 70 .9 12 .1 17.2 28 .4 The g r e a t e s t c o n c e n tra t io n s o f t r o u t and w h i te f i s h f in g e r l i n g s were found n e a r th e h e ad g a te s o f 3 c a n a ls . F in g e r l in g t r o u t ta k e n downstream a d ja c e n t to th e h eadga te o f th e Low L ine Canal t o t a l e d 384, o f which 8 2 .5 ^ were brown t r o u t . The number o f w h i te f i s h f in g e r l i n g s found in th e same a re a was 461. There were 287 t r o u t and 120 w h i te f is h f in g e r l i n g s ta k en betw een th e h e adg a te s o f th e Farm ers C ana l. The dom inant s p e c ie s in th is case was b rook t r o u t (8 3 $ ) . In 1800 f e e t b eh ind th e h eadg a te o f th e K le in schm id t C ana l, 63 t r o u t (79$ rainbow ) and I 85 w h i te f i s h f in g e r l i n g s wpre c a p tu re d . A few t r o u t and w h i te f i s h f in g e r l i n g s were found f a r down most c a n a ls . A maximum do>m-canal movement ob served f o r any f i n g e r l i n g was app ro x im a te ly 14 m ile s . Non-game s p e c ie s were found i n a l l o f th e c an a ls s tu d ie d . Small longnose su ck e rs were numerous in a l l b u t th e s p r in g - f e d A lliso n -L ew is D itc h and in th e 3 d i tc h e s which o r ig in a te d n e a r e s t th e mouth o f G a l l a t in Canyon. White su ck e rs were r a r e ex cep t in th e Beck and B order C ana l. The average le n g th f o r a l l su ck e rs ta k en was app rox im a te ly 6 in c h e s . Only 5 o f th o se c ap tu red in 1951 were over 15 in ch e s in t o t a l le n g th . Thousands 28 o f su ck e r f r y were observed, in most o f th e c a n a ls . A dult s c u lp in s and f r y were a ls o ab und an t, e s p e c i a l l y n e a r th e h e a d g a te s . Dace were found in most d i tc h e s b u t n o t in la rg e numbers. E s tim a te d l e g a l game f i s h lo s s E s tim a te s o f th e t o t a l numbers and pounds o f l e g a l game f i s h (7 in c h e s o r over in t o t a l le n g th ) were made f o r 11 o f th e 13 c an a ls s tu d ie d ( t a b l e 5 )• A ll e s t im a te s were based on th e 1951 se a so n , ex cep t f o r th e Keughen Canal which was 1950. Each c an a l was d iv id e d in to 3 s e c t i o n s . f o r th e pu rpose o f making e s t im a te s . The f i r s t s e c t io n in c lu d e d th e o n e -h a lf m ile o f c an a l im m ed ia te ly b eh ind th e h e ad g a te . The second in c lu d ed th e u pp e r o n e -h a lf o f th e d i t c h a d ja c e n t to th e f i r s t s e c t io n , and th e t h i r d th e rem a inder o r most d i s t a l p a r t o f th e c a n a l . S easonab le e f f o r t was made to secu re r e p r e s e n ta t iv e samples in each o f th e 3 p a r t s . So c o r re c ­ t i o n wa.s made f o r f i s h movement i n to o r out o f th e c a n a ls . The s e c t io n s sampled in th e 11 c an a ls ranged from 3 .1$ to 45 .5$ o f t h e i r e n t i r e le n g th s ,. I Because o f th e sm a ll sam ples ta k en in th e M oreland and H eeb-D uffin C an a ls , th e s e were n o t u sed in th e e s t im a te s . Only s e c t io n I o f th e C la rk D itch was in c lu d e d because i t was th e on ly p o r t io n c o n ta in in g w a te r a t th e tim e o f shock ing . F ish lo s s showed l i t t l e c o r r e l a t i o n w ith any o f th e u su a l p h y s ic a l c o n d it io n s observed such as s iz e o r ■volume o f flow , ^ o th th e High L ine and Low L ine C anals a re la rg e on th e b a s i s o f le n g th and volume o f flow , y e t th e e s t im a te d 23 pounds o f l e g a l game f i s h in th e H igh Line Canal and 71 pounds in th e Low L ine Canal a re r e l a t i v e l y sm a l l . ■ On th e o th e r hand , th e Farmers and K le in sohm id t C an a ls ? which had th e g r e a t e s t volumes o f f low , a t t r a c t e d a la rg e number o f f i s h (e s t im a te d over 240 pounds e a c h ) . These d i tc h e s had c re ek s e n te r in g them , and t h i s r a th e r th a n t h e i r s iz e may have accoun ted f o r th e abundance o f f i s h . The Beck and B order C ana l, i n s p i t e o f i t s sm a l le r s i z e , had an e s t im a te d poundage o f f i s h 4 tim es g r e a t e r th an th e Keughen C ana l. T h is c an a l i s u ndoub ted ly in f lu e n c ed by H y a l i te Creek which e n te r s i t . The sm a ll s p r in g - f e d A lliso n -L ew is D itch had an e s t im a te d 289 pounds o f l e g a l game f i s h . T h is i s th e l a r g e s t f o r any c an a l s tu d ie d . L osses e s t im a te d f o r o th e r sm all c a n a ls ranged from 5 t o 33 pounds. A t o t a l o f 866 l e g a l game f i s h w e igh ing 352.8? pounds were ta k en in a l l sam ples from th e 11 c a n a ls . U sing t h i s as a b a s i s , th e t o t a l e s t i ­ m ated lo s s in th e s e d i tc h e s would be 2835 l e g a l game f i s h w eigh ing 1186 pounds. I f th e s e 11 c a n a ls a re r e p r e s e n ta t iv e o f th e 52 West G a l la t in E iv e r c a n a ls in th e s tu d y a r e a , th e t o t a l e s tim a te d lo s s would be 13,400 l e g a l game f i s h w e igh ing 56OO pounds. T h is a re a o f th e West G a l la t in E iv e r y ie ld e d an e s t im a te d 16 ,100 f i s h w eigh ing 10,300 pounds to th e fish e rm an in 1949 and 16 ,300 f i s h w e igh ing 11,300 pounds in 1950 (M isso u ri E iv e r B asin S tu d ie s , 1 951 ). Suckers made up s l i g h t l y more th a n 1$ o f th e s e numbers. 29 Summary 1 . F ish lo s s and movement was i n v e s t ig a te d d u rin g 1950 and 1951 in i r r i ­ g a t io n c a n a ls from th e West G a l l a t in E iv e r , Montana. 2 . Two-way f i s h w e irs were employed to s tu d y f i s h movement in th e Keughen 30 and Low Line C an a ls . D eL ris -Iad en w a te r p re v en ted w e ir o p e ra t io n d u r in g th e s p r in g and f a l l segments o f th e i r r i g a t i o n s e a so n s , 3 . I n th e Keughen Canal th e r e was a t o t a l o f 502 i n i t i a l down- and 322 i n i t i a l u p -c a n a l m ig ran ts d u r in g 6 l days in 1950* T rou t com prised 3 .5 # o f th e t o t a l i n i t i a l movement, w h i te f i s h 4 .5 # j and non-game s p e c ie s 9 2 .0 # . I n 84 days o f t r a p o p e ra t io n in 1951> 546 i n i t i a l m ig ran ts moved down and 353 moved up th e c a n a l . Of t h i s t o t a l move­ m ent, 6 ,1 # were t r o u t , 8 .6 # were w h i te f i s h , and 85 .3# were nonr-game s p e c ie s , 4 . The Low L ine w e ir , which o p e ra te d 41 days i n 1951? showed an i n i t i a l f i s h movement o f 65 down- and 132 u p -c a n a l m ig ra n ts . The t o t a l i n i t i a l movement was 39*1# t r o u t , 13 .2# w h i te f i s h , and 47 .7# non-game s p e c ie s . 5. A ll s p e c ie s o f f i s h ta k e n ex cep t c u t th r o a t t r o u t showed movement i n "both d i r e c t io n s th ro ugh e i t h e r th e Keughen o r Low L ine w e irs , 6 . A d i r e c t c o r r e l a t i o n e x i s t e d betw een sev e re w a te r f lu c tu a t io n s and t r o u t movement u p s tream in th e Low L ine C ana l, A t o t a l o f 59 t r o u t o r 88# o f a l l u p -c a n a l m ig ran ts f o r th e e n t i r e sea son came ou t f o l ­ low ing 3 w a te r r e d u c t io n s . 7 . F ish lo s s ( o r g a in ) th ro ugh th e w e irs w h ile th e y o p e ra te d was e s ta b ­ l i s h e d by a c tu a l c o u n ts , 8 . T h i r te e n c an a ls were sampled in 1951 by sho ck in g , p o iso n in g o r can­ v a s s in g . . Game f i s h c o n c e n tra t io n s were found n e a r h e a d g a te s , n e a r c re ek s where th e y e n te r e d a c a n a l , and in I s p r in g - f e d d i t c h . Brook t r o u t was th e 9 31 dom inant t r o u t s p e c ie s in th e v i c i n i t y o f c re ek s and s p r in g s . 10 . The s p e c ie s com position o f 1882 t r o u t ta k en by sam pling in 1951 was 46 . 1$ brook t r o u t , 37«6$ brown t r o u t , 16.2% ra inbow t r o u t , and 0.1% c u t th r o a t t r o u t . F in g e r l in g t r o u t com prised 54»7% o f th e t o t a l num­ b e r . About 97.7% o f th e 894 w h i te f i s h c ap tu red were f i n g e r l i n g s . 11 . Eon-game s p e c ie s were numerous i n most o f th e c a n a ls s tu d ie d . Suckers p redom ina ted ; t h e i r average le n g th was app rox im a te ly 6 in c h e s , 12 . F is h lo s s d id n o t seem to be c o r r e la t e d w ith le n g th o r volume o f f low . I t was e s t im a te d t h a t 2835 l e g a l game f i s h (7 o r more in ch e s in ■ le n g th ) w eigh ing 1186 pounds were l o s t to 11 c a n a ls in th e s tu d y a r e a . O 32 L i te r a tu r e c i t e d H o lto n , Cr. D. 1952. A t r o u t p o p u la t io n s tu d y on a sm a ll c re ek in G a l l a t in County, M ontana. U npub lished t h e s i s , Montana S ta te C o lle g e . pp I - 46 . Huntsman, A. G. 1945. F r e s h e ts and f i s h . T ran s . Am. F is h . S o c ., 75: 257-266 . M isso u ri B iv e r B asin S tu d ie s , F ish and W ild l i f e S e rv ic e , USBI. 1951 . A tw o -y ea r f i s h e r y in v e s t i g a t i o n o f th e West G a l l a t in B iv e r , M ontana, 1949-1950, m imeograph, pp 1- 38 . Montana F ish and Game D epartm en t. 1904 . (F is h s c r e e n in g ) . Second B ie n n ia l B eport o f th e S ta te F ish and Game Warden, S ta te o f Mont. 1903-1904. pp 1 -197 . ____________________ • 1942. F ish s c re e n in g and p la n t in g . Mont. F ish and Game Comm., B ie n n ia l B e p o r t , 1941-1942. pp 1 -122 . . S h a t t e r , D. S . 1938. A two-way f i s h t r a p f o r use in s tu d y in g s tre am - f i s h m ig r a t io n s . T ran s . Ho. Am. W ild l. C o n f., 3: 331-338. Snedec o r , G. W. 1946. S t a t i s t i c a l m ethods. Iowa S ta te C o llege P r e s s , Ames, Iowa, pp I - 485 , 4 th Ed. W ales, J . H. 1948. C a l i f o r n i a 's f i s h s c re e n program , C a l i f . F ish and Game, 3 4 (2 ) : 4 5 -51 . • '■ V MONTANA STATE UNIVERSITY LIBRARIES 762 1001 3344 4 N378 C624£ cop .3 Clothier, VJ. D. 123664 L O L U l c t J W • V * 4 . 4 n - i V ‘1 Fish loss and movement in ir* igation diversions from the West Gallatin River, Montana t C o f - f I 23LL(I'