EBEL: TRANSPORTATION OF CHINOOK SALMON AND STEELHEAD SMOLTS 



Table 12. — Comparison between transported and nontransport- 

 ed (control) chinook salmon of 1971 that were captured during 

 1973 as adults in the commercial, Indian, and sport fisheries in 

 the lower Columbia River. (Numbers observed, not estimated.) 



Transported 

 Dalton Point Bonneville Dam 



Control 



Recaptures 



Item 



No. 



Recaptures 



No. % 



Recaptures 



No. 



Upstream from 

 Bonneville Dam 

 (Indian fishery) 



Downstream from 

 Bonneville Dam 

 (commercial and 

 sport fisheries) 



Total 



14 



9 

 23 



0.046 



0.029 

 0.075 



14 



18 

 32 



0.040 



0.051 

 0.091 



0.019 



0.010 

 0.029 



Combined recoveries 

 (Dalton Point and Bonneville Dam)' 



0,083 



0.029 



'Transport/control ratio = 2.86:1. 



suggests that perhaps the adult fish from trans- 

 ported stocks were spending a longer time in the 

 lower river, thus allowing a greater catch of these 

 groups. 



Recovery of Marked Steelhead in the 

 Indian and Sport Fisheries 



The Indian fishery of the lower Columbia River 

 in 1973 and 1974 was not sampled because of clo- 

 sures during most of the season. However, in 1975 

 a substantial fishery was in progress. Sampling of 

 this fishery yielded 39 marked steelhead from 

 1973 experimental releases. Thirty-eight of these 

 were from transported groups; only one fish of a 

 control group was recovered. The ratio of transport 

 to control was 30:1, again indicating a higher 

 catch rate of transported steelhead in 1973 than 

 was recorded at Little Goose Dam where the 

 transport/ control ratio was 13.4:1. 



Table 13. — Recoveries of adult steelhead from the sport fishery 

 upstream from Little Goose Dam. Juveniles were released, 1971- 

 73, as controls at Central Ferry; transported groups were re- 

 leased at Dalton Point and Bonneville Dam. 



'Transport/ control ratios computed from the combined recoveries of the 

 Bonneville Dam and Dalton Point releases. 



The sport fishery upstream from Little Goose 

 Dam in the Snake River was intensive in 1972 and 

 1973 but was closed for a portion of 1974. Sam- 

 pling of this fishery yielded 310 marked steelhead 

 (Table 13) from experimental releases in 1971-73. 

 The transport/control ratio estimated from these 

 recoveries indicated a benefit from transport, but 

 the benefit was about half that indicated 

 downstream at Little Goose Dam from releases in 

 1971 and 1972. The benefit was substantial in all 

 recovery locations from releases in 1973. 



Returns of Adult Experimental Fish to 

 Hatcheries and Spawning Grounds 



Spawning ground surveys and examination of 

 adult fish in Idaho hatcheries provided further 

 information concerning transport/ control ratios of 

 chinook salmon and steelhead at their "home" des- 

 tination. 



Adult chinook salmon returns were examined at 

 Rapid River Hatchery; steelhead returns were 

 examined at Dworshak National Fish Hatchery 

 and at the Pahsimeroi Hatchery (Table 14). Ex- 



Table 14. — Returns of adult chinook salmon and steelhead to hatcheries of the upper Snake River drainage, 1971-73. 



'T = transported group; C = control. 



501 



