FISHERY BULLETIN: VOL. 87, NO. 4, 1989 



Table 8. — Relationship of juvenile salmonid size to fyke net capture loca- 

 tion. Key: S1,S2= sfioreline stations, B1-B4 = barge stations, s = surface, 

 m = middeplfi, b = bottom, ns = not sampled. 



studies, most fish were collected in shoreline 

 areas, but catches from one shoreline were about 

 three times greater than catches from the oppo- 

 site shoreline. Thus, the physical features of 

 some shorelines appear to influence the distribu- 

 tion of juvenile fall chinook salmon. 



Low catches of chinook salmon smolts during 

 the late summer may reflect the small popula- 

 tion size in upriver areas. The number of sum- 

 mer and fall chinook salmon spawning above 

 Priest Rapids Dam in 1982 was lower than the 

 1972-82 10 yr average." The total outmigi-ation 

 of up-river 0-age chinook salmon in 1983 was 

 about 1 million fish (estimate based on escape- 

 ment of adult summer and fall chinook salmon 

 over Priest Rapids Dam in 1982 and historical 

 production factors), or only 40% of the numbers 

 estimated by Sims and Miller (1977) for the 1976 

 outmigration. Because the mouth openings of 

 the four barge fyke nets collectively only 

 sample 0.1-0.2% of the river cross section, 

 small sample numbers would be predicted for 

 fish present at low densities. 



Species-specific differences in behavior also 

 affected spatial distribution. For example, al- 



"Rod Woodin, Washington Department of Fisheries, 

 Olympia, WA 98504, pers. commun. November 1983. 



most all sockeye salmon smolts were collected 

 from midstream portions of the river. This phe- 

 nomenon was not entirely consistent with the 

 size-related model of fish distribution noted for 

 the different groups of juvenile chinook salmon. 

 Other studies of lateral distribution have shown 

 that yearling sockeye salmon migi'ate primarily 

 in midriver, utilizing areas of highest current 

 velocity (Dames and Moore 1982). The apparent 

 preference of juvenile sockeye salmon for the 

 river bottom near our study site also contrasts to 

 that observed for lentic populations, which re- 

 portedly migrate primarily near the surface 

 (Johnson and Groot 1963). 



Electroshocking and beach seining showed 

 that the shoreline fyke nets could not be used to 

 effectively collect larger juvenile salmonids. Al- 

 though differences in gear effectiveness make 

 direct comparison of methods impossible (Hul- 

 bert 1983), it appears that nearshore estimates 

 of distribution based on shoreline fyke net 

 catches were low. For example, spring salmon 

 and steelhead smolts were sometimes electro- 

 shocked at night in nearshore areas ~1 m deep, 

 but none were collected in shorehne fyke nets 

 that were fished at similar depths. Daytime 

 catches in shoreline fyke nets were also low 

 when compared with the observed densities of 



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