Trophic Ecology
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Molly Sturdevant
Auke Bay Laboratories
Alaska Fisheries Science Center, NOAA Fisheries
Ted Stevens Marine Research Institute
17109 Pt Lena Loop Rd
Juneau AK 99801
(907) 789-6041
Molly.Sturdevant@noaa.gov
Studies on the trophic ecology of salmon in the MSI Program at ABL
have taken several directions. In Southeast Alaska and Prince
William Sound, we have examined food habits of juvenile salmon on
spatial and temporal scales, diet overlap and feeding declines of
co-occurring salmon species and potential competitors, standing stock
and composition of prey in different marine habitats, seasonal plankton
abundance during salmon fry outmigration, relationship of diet to
condition factor and growth, and density dependent effects on growth,
and predation on juvenile salmon by congeners and other fish.
These studies traditionally have been labor intensive, requiring
extensive microscopic analysis of prey items observed in individual fish
stomachs or plankton samples.
Current food habits research is conducted with a bioenergetics
approach. With the acquisition of a microbomb calorimeter in 2001,
we anticipate measuring seasonal whole body energy content of local
hatchery and wild stocks of chum salmon. This tool will provide an
alternate and perhaps more accurate measure of condition of juvenile
salmon during their annual migration through various marine habitats to
the Gulf of Alaska. We will also conduct field experiments to
measure gastric evacuation rates and diel feeding periodicity of
juvenile chum salmon to determine their daily ration. In
conjunction with other information on growth and consumption, these
species-specific parameters will be applied in a bioenergetics model to
address carrying capacity and survival.
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