Evaluation of Growth and Survival on the Recruitment of Chinook Salmon in Two Southeast Alaska Rivers
Evaluation of Growth and Survival on the Recruitment of Chinook Salmon in Two Southeast Alaska Rivers
Monday, August 22, 2016
This study will evaluate the importance of freshwater and marine processes on female Chinook Salmon Oncorhynchus tshawytscha recruitment to spawning age in the Stikine and Chilkat rivers using long-term scale archive samples, adult abundance estimates, and smolt data sets. Spawning escapement on the Chilkat River has declined significantly over time (1991-2014; P = 0.0001), while spawning escapement on the Stikine River has a negative trend over time (1996-2014); this relationship is not significant (P = 0.07). Preliminary analyses on the downstream smolt outmigration of Chinook Salmon in the Chilkat River showed that the mean duration of the smolt run from 2001-2010 was 34.6 days and on average, began and ended on Julian day 102 and 137, respectively. There is a positive linear relationship (R2= 0.46, P = 0.0001) between mean smolt fork length and Julian day of migration where, on average, smaller fish were present at the start of the run while larger fish were more prevalent at the end of the run. This evaluation will allow for the development of more accurate and reliable forecasts for Chinook Salmon stocks in the region and assist in management decisions and setting escapement goals in these two southeastern Alaska rivers.