Evaluation of Growth, Survival, and Recruitment of Chinook Salmon in Southeast Alaska Rivers

The importance of freshwater and marine processes on female Chinook salmon Oncorhynchus tshawytscha recruitment to reproductive age was examined in the Taku and Unuk rivers (southeastern Alaska) using long-term adult and smolt data sets.  These evaluations will allow for the assessment of growth and survival on recruitment within individual stocks by following cohorts from freshwater through marine residence until they return to their natal river as reproductively mature adults.  Abundance of adult female Chinook Salmon escapements in the Taku River ranged from 4,120 to 70,691 fish between 1973 and 2007. Between 1991 and 2005, Taku River smolt abundance ranged from 1,112,499 to 3,470,479 smolts. Escapement of female Chinook Salmon in the Unuk River ranged from 475 to 6,757 fish between 1986 and 2013.  Smolt abundance estimates in this system ranged from 166,792 to 491,357 individuals between 1994 and 2005. For both systems, adult female escapement, female body length, water temperature, and smolt body length, weight, and condition were not significant linear predictors of Chinook Salmon smolt production. This evaluation will allow for the development of more accurate and reliable forecasts for making management decisions on Chinook salmon stock status and escapement goals in southeastern Alaska rivers.