Table 4.-Percentage return and benefit or deficit (-) of transported to nontransported (control) juvenile 

 steelhead trout (released in 1969-70) that were recaptured as adults at Ice Harbor and Little Goose dams, 

 1970-73. 



Release site and 

 (in parentheses) 

 experimental 

 group offish 



Number of 

 juveniles One 



Number recaptured as adults 



Two 



Three 



Percentage return 

 as adults 



Percentage 

 transported 

 to control 

 benefit or 



released' ocean ocean ocean Total Observed Estimated^ deficit (-) 



1969: 

 Ice Harbor Dam 



(control) 

 John Day Dam 



(transported) 



1970: 

 Ice Harbor Dam 



(control) 

 John Day Dam 



(transported) 

 Bonneville Dam 



(transported) 



174 



-7 

 47 



'Adjusted for initial tag loss. 



2Based on comparison of the known recovery of fish with magnetized wire tags at Little Goose Dam and the 

 subsequent recovery of these and other marked fish at a hatchery unstream from Little Goose Dam. Returning 

 fish identified at the dam were marked with dart and law tags and released to continue their migration up- 

 stream. Numbers of externally-tagged fish arriving at Dworshak Hatchery were compared with the recovery of 

 other wire-tagged fish not previously detected and identified at Little Goose Dam. 



turns from this release were 7% less than returns 

 from controls). 



Recovery of Marked Chinook Salmon 

 in Commercial and Sport Fisheries 



Although only 43 adult chinook salmon (Table 5) 

 were recovered in the commercial and sport 

 fisheries from juvenile releases in 1969, returns 

 indicate a definite benefit from transportation. 

 The benefit of transported fish (John Day- 

 Bonneville releases combined) was 19%. 



It was not possible to distinguish between re- 

 turns of adults to the fishery from juvenile 

 releases at Bonneville and John Day because of the 

 loss of the identifying brands. Brands which would 

 have enabled identification by release site were 

 obliterated by gillnet abrasion. Transported and 

 control groups of juveniles could be distinguished 

 as adults by magnetic tags, but only two codes 



Table 5.-Comparison between transported and nontransported 

 groups of chinook salmon based on numbers of transported and 

 nontransported juvenile fish (released in 1969) that were cap- 

 tured as adults by commercial and sport fisheries in the lower 

 Columbia River, February through August 1971 and 1972. 



No. of salmon 

 recaptured as adults 



Transported Nontransported 



Location of fisheries 



Upstream from Bonneville Dam 



(Indian fishery) 8 



Downstream from Bonneville Dam 17 



Total 25 



4 

 14 



18 



were used— one for the controls and one for the 

 transported fish (Bonneville and John Day com- 

 bined). However, if the percentage of adult re- 

 turns obtained at Ice Harbor and Little Goose 

 dams— where brands of fish returning from 

 releases at Bonneville and John Day were 

 visible-is applied to the total returns of adults as 

 obtained in the commercial fishery, the benefit 

 from transporting juveniles becomes 59% for 

 chinook salmon transported to Bonneville Dam. 



Adult recoveries in the lower river commercial 

 and sport fisheries from juvenile chinook salmon 

 released in 1970 were insufficient (seven trans- 

 ported and eight control fish) for analysis of 

 transport to control return ratios. 



Returns of Adult Chinook Salmon 

 to Spawning Grounds 



Spawning ground surveys (Figure 2) and 

 examination of tagged adult chinook salmon at 

 Rapid River Hatchery near Riggins, Idaho, 

 provided further information concerning benefits 

 at their "home" destination from transport of 

 juvenile spring- and summer-run chinook salmon. 



In 1971, 12 tagged adult fish (from the 1969 

 juvenile release) were recovered from the Rapid 

 River Hatchery; an additional 15 were from sport 

 fishermen and spawning ground surveys. Of the 

 total, 15 adults were from the transported groups 

 and 12 from the control group. By adjusting from 

 the ratio of John Day to Bonneville adult returns, 

 we estimated that 12 of the 15 transported fish 



928 



