JUL! auGUST _ JUL'' AUGUST 



Figure 6. — Number of tagged aockeye observed at Rockj- 

 Reach and Zosel Dams after release in the Rock. Island 

 forebay in 1962 and 1963. The dates of release are desig- 

 nated by triangles below the base lines and the number of 

 fish released is given in jiarentheses. Daily average tem- 

 perature of the Okanogan River is given in the center panel. 



Rock Island Dam in 1954 have been groupod be- 

 cause of the small numbers wliich were observed at 

 Zosel Dam. These grouped releases peaked at Rock 

 Island Dam on July 25, July 31, and .\up;ust 7 and 

 at Zosel Dam 8 to 9, 7 to 8, and 7 to 8 days later. 

 After Rocky Reach Dam was built, certain 

 changes ai)pcar(>d in the travel time. 'I'agKcd 

 sockeye salmon tliat had been released in the Rock 

 Island forebay on July 19-20, 21-23, and 24-26, 

 I !)()'_*, appeared in greatest numbers at Zosel Dam 

 on August 11-13, 7-13, and 7-12. Travel times for 

 the three groups were 22 to 25, 15 to 23, and 12 to 

 1(1 days, respectively. The travel times in 19()3, on 

 the other hand, were similar to those before Rocky 

 Reach Dam was built — the releases of July 10-12, 

 17-18, and 23-24 appeared in greatest numl)ers at 

 Zosel Dam after 7 to 11,8 to 12, and 8 to 9 days, 

 respectivelJ^ 



Table 3. — Xumber of tugged sockcyc salmon ohseri'cd at Rock Idaml and Zosel Dams after release lietoir Hock Island Dam, 1953 



and 1!);14 



Table 3. — Number of tagged sockeye salmon obsereed at Rock Island and Zasil Dams after riUase below Rack Island Dnni. tn/iS 



and 195/f — Continued 



138 



U.S. FI.su AM) V.Il.DI.IFK SKKVUIE 



