I am using historical migratory timing data from sockeye salmon populations in Washington, British Columbia and Alaska. I plan to develop a comprehensive explanation of the basic patterns of average migratory timing over the North American range of sockeye salmon by relating average timing patterns to the average environmental conditions experienced by each population. I am also investigating interannual variation in migratory timing within populations to determine whether this variation correlates to environmental conditions such as sea surface temperature, lake outlet temperature and flow. Part of this heterogeneity arises from variance in abiotic variables such as temperature, oxygen, and light while other aspects result from the spatial distributions and behavioral differences in the organisms that inhabit lakes. Implicit in these links is the interactions of predators and prey, which in turn depend on their spatial distributions.
Humans increasingly impact aquatic ecosystems through fishery exploitation and eutrophication.
The relatively pristine lakes in the Wood River system provide a good reference system for comparing differences in the spatial dynamics of fish predators and their prey with lakes that are more heavily impacted such as Lake Washington. I use hydroacoustics to measure changes in the spatial distributions of sockeye salmon over diel periods and compare them to those I observe in more impacted Washington lakes. I will then incorporate these data into ecosystem models to answer questions like how differences in prey fish aggregation change predator foraging behavior and how predator foraging efficiency affects energy flux. My project will include three primary objectives. First, to compare the correlation between stock abundance, as a method of interpreting the spatial scale and form of environmental and productivity variation across spawning groups.