IAB Research Project Description
Ecology and Demographics of Chinook Salmon
Chena River, Alaska. Photograph by Mark Wipfli/IAB/Alaska Cooperative Fish and Wildlife Research Unit/UAF
Salmon strips hang on a rack in one of the rural Alaska communities investigators from the Center for Alaska Native Health Research. Many Yup'ik Eskimo depend on local wild food to feed their families and themselves. CANHR is looking at obesity and genetics, indigenous teen resilience, nutrition and contaminants in subsistance foods, and other biomedical subjects. Credit: Gunnar Ebbesson
The goal of the work we propose is to improve our understanding of the way ecological processes regulate population size and generate annual variability in the abundance of adult Chinook salmon (Oncorhynchus tshawytscha) returning Stock-recruitment models do not take into account essential environmental conditions and processes that affect chinook rearing and overwintering, and therefore lack rigor and reliability.
The goal of this work is to improve our understanding of the way ecological processes regulate population size and generate annual variability in the abundance of adult Chinook salmon, (Oncorhynchus tshawytscha), returning to the Chena and Salcha Rivers.
To achieve this goal we will pursue three lines of research.
First, we will investigate the causes of density dependent mortality that regulates population size. Evidence suggests this occurs during the summer that juveniles rear in freshwater and that it is a consequence of competition for food and space.
Second, we will investigate how seasonal patterns of stream discharge affect food production and the area and quality of profitable and safe feeding habitat. Preliminary analyses suggest annual variation in summer discharge may account for 75% of the variability around the stock-recruitment curve.
Third, we will use a retrospective analysis to develop and test hypotheses about the way ecological processes generate annual variations in the abundance of Chinook salmon. We will employ what we learn from this analysis to develop a stock-recruitment analysis that incorporates environmental processes.
The results of this analysis will allow biologists and managers to predict optimal escapements and forecast future returns. Juvenile chinook will be captured with seines and minnow traps, and their densities, condition, and diets measured; adult numbers estimated via existing ADFG adult counts; and food resources (invertebrates) estimated with benthic and drift nets, and terrestrial infall traps.
1 Apr 2010 – 31 Mar 2011
IAB Proposal #2007-026RV
UAF Grant #G6280
IAB Project #216
302A Irving I
University of Alaska Fairbanks
Fairbanks, AK 99775-7000