FISHERY BULLETIN: VOL. 78, NO. 2 



Table 5. — Analysis of variance of comparative percentage returns of adult chinook salmon and 

 steelhead to Little Goose Dam for transported and nontransported (control) juveniles, 1971-73. 



•P 0.05; "P 0.01. 



Table 6. — Analysis of variance of comparative percentage 

 returns of adult chinook salmon and steelhead to Little Goose 

 Dam for transported and nontransported (control) juveniles, 

 1971-73 (returns analyzed by species). 



Source 



Chinook salmon return data 

 df SS 



MS 



Partition of treatment sum of squares (above) comparing adult chinook salmon 

 returns for control vs. transport and Dalton Point vs. Bonneville Dam. 



Control vs. transport 

 Bonneville vs. Dalton Point 



1 1 .604 

 1 0.014 



1.604 

 0.014 



48.45" 

 0.4342NS 



Source 



Steelhead return data 

 df SS 



MS 



Partition of treatment sum of squares (above) comparing adult steelhead re- 

 turns for control vs. transport and Dalton Point vs.Bonneville Dam. 



Control vs. transport 

 Bonneville vs. Dalton Point 



4.223 



0.062 



4.223 



0.062 



iseer* 



0.020NS 



• = P'-0.05; " = P' 0.01; NS = nonsignificance. 



coveries from the Dalton Point and Bonneville 

 Dam release sites for either chinook salmon or 

 steelhead. 



Percentage Adult Returns of 

 Transported Releases 



Analysis of the transport/control ratio provides 

 the best insight as to the possible benefits from the 

 transportation system, but total percentage re- 

 turn obtained from the groups transported must 

 also be examined to accurately assess the effec- 

 tiveness of the system as it operated. If both trans- 

 port and control groups were excessively stressed 

 during the diversion, collection, marking, and 

 transport operations, then percentage returns 

 would have been abnormally low even though 



transport/ control ratios were favorable. I, there- 

 fore, compared percentage returns of the transport 

 groups with percentage returns of production re- 

 leases achieved at Dworshak and Rapid River 

 Hatcheries and with estimated percentage re- 

 turns of steelhead and chinook salmon to Little 

 Goose Dam. 



Returns from production releases of juvenile 

 steelhead at Dworshak Hatchery (Olson^^) were 

 0.25% in 1971, 0.20% in 1972, and 0.052% in 1973. 

 Corresponding estimated percentage returns of 

 steelhead from those transported from Little 

 Goose Dam in 1971, 1972, and 1973 (returns from 

 Dalton Point and Bonneville Dam releases com- 

 bined) were 1.4, 1.8, and 2.7%, respectively. Al- 

 though the sport fishery for steelhead above Little 

 Goose Dam in 1973 would have reduced the per- 

 centage returns to Dworshak for releases in 1971, 

 the estimated catch of 2,459 (Petit^'^) when added 

 to the total hatchery returns, resulted in a return 

 percentage of<0. 50 for the 1971 release. The sport 

 fishery was closed from 1974 to 1976; thus returns 

 from releases in 1972 and 1973 at Dworshak 

 Hatchery were not affected. 



I also compared percentage adult returns of 

 steelhead with the estimated percentage adult re- 

 turns from populations of natural migrants pass- 

 ing Little Goose Dam in 1971, 1972, and 1973 by 

 Raymond (1979, see footnote 2). His estimates of 

 percentage returns were based on counts of adults 

 passing the dam and estimates of populations of 

 smolts (both hatchery and wild) passing Little 

 Goose Dam for a given year. His estimates of per- 

 centage adult returns of steelhead to Little Goose 



"Wayne Olson, Hatchery Manager, Dworshak National Fish 

 Hatchery, Ahsahka, Idaho, pers commun. 1973-76. 



'^Steven Petit, Senior Fisheries Research Biologist, Idaho 

 Fish and Game Dep., Lewiston, Idaho, pers. commun. June 1974. 



498 



