Joshua Green River Pacific Salmon Stock Assessment and Resident Fish Species Survey, Izembek National Wildlife Refuge, Alaska 1994-1996

摘要

In 1994-1996, four species of Pacific salmon, and Dolly Varden char Salvalinus malma were captured in the Joshua Green River on the Izembek National Wildlife Refuge. Chum salmon Oncorhynchus keta, were first captured in late June all 3 years, but a bimodal capture distribution indicated an early and late run. The early run preferred the right fork, while the late run used primarily the left fork. Sockeye O. nerka and pink salmon O. gorbuscha used primarily the right fork, and although coho salmon O. kisutch used both forks, capture rates also indicated a strong preference for the right fork. The early chum salmon run peaked in mid-July while the late run peaked in early September. Sockeye salmon peaked in mid-July, while pink salmon peaked in the first half of August, and coho salmon appeared to peak during the second half of September. Sex composition was variable among species. During all 3 years, the percent of female chum, coho, and pink salmon captured in most locations generally increased throughout the season while the percent of female sockeye salmon was variable throughout the run.