Size and Years-in-Ocean of Adult 

 Experimental Fish 



Since transported fish (chinook salmon and 

 steelhead) had the opportunity to enter the ocean 

 more than 1 mo earlier than control fish that mi- 

 grated naturally, the size and ocean age of return- 

 ing adults were examined to determine whether a 

 difference existed. The average weights of chinook 

 salmon and steelhead released as controls were 

 compared with the average weights of transported 

 groups returning at the same ocean age. A paired 

 comparison ^test using the data from Table 9 

 showed no significant differences in average 

 weights for chinook salmon and steelhead 

 (chinook salmon: t = 0.315, P>0. 5; steelhead: t = 

 0.297,P>0.5df =8). 



The ratio of age .3 to age .2 chinook salmon and 

 the ratio of age .2 to age .1 steelhead were com- 

 pared (Table 10) between transported and control 

 groups. These comparisons indicated whether 

 transporting affected the time that fish spent in 

 the ocean before their return to Little Goose Dam. 

 An analysis of variance of the ratios for the 3 yr of 

 the study (Table 1 1 ) showed that the differences in 

 ocean age between transported and control 



Table 9. — Average weights (kilograms) of returning chinook 

 salmon and steelhead to Little Goose Dam from control (C) and 

 transported (T) releases of smolts, 1971-73. 



Table lO. — Comparison of transport and control age ratios on 

 adults returning to Little Goose Dam, 1971-73. Chinook salmon 

 age .3/. 2 and steelhead age .1/.2 were used to determine ratios. 



FISHERY BULLETIN: VOL. 78, NO, 2 



Table ll. — Analysis of variance of ratios of ocean age .3 to .2' 

 chinook salmon and age .2 to .1 steelhead adults returning to 

 Little Goose Dam from transported and control releases. 



'Age designation follows the formulas of Koo (1962). The number of years at 

 sea is shown by an Arabic numeral preceded by a dot. 



*P'0.05. 



'Age designation follows the formulas of Koo (1962), The number of winters 

 at sea is shown by an Arabic numeral preceded by a dot 



steelhead were not significant (P<0.05). A sig- 

 nificant (P<0.05) difference in ocean age between 

 control and transported chinook salmon did occur 

 with a slightly higher ratio of .3/.2-age chinook 

 salmon indicated among control returns. By these 

 analyses, the transportation of smolts to locations 

 downstream from Bonneville Dam was not shown 

 to influence either the age or size of returning 

 adult steelhead but may have influenced age of 

 returning adult chinook salmon. 



Recovery of Marked Chinook Salmon in 

 the Commercial and Sport Fisheries 



The experimental plan to evaluate recoveries of 

 adult chinook salmon in the commercial, Indian, 

 and sport fisheries required sampling of these 

 fisheries each year from 1973 to 1975. However, 

 the spring chinook salmon run began a rapid de- 

 cline in 1973, which forced the commercial fishery 

 to close in 1974 and 1975. As a consequence, 

 sufficient data on chinook salmon were obtained 

 only in 1973 for comparison of transported and 

 control recoveries. A test fishery was conducted in 

 1974 and 1975, but only 18 salmon were recovered 

 from the experimental releases during these 

 years — too few to make comparisons of recoveries. 

 Sixty-one salmon (Table 12) were recovered in 

 1973 from the 1971 experimental releases. The 

 combined transport/control ratio of these re- 

 coveries, computed after adjusting the number of 

 juveniles released, indicated that chinook salmon 

 transported as juveniles were captured at 2.86 

 times the rate of control fish. This is a substan- 

 tially higher test/control ratio than the 1.6:1 com- 

 puted for returns to Little Goose Dam, indicating 

 that transported groups were captured at a higher 

 rate in the fishery than at Little Goose Dam. This 



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