SS1.07 Ecological Links to Population Dynamics and Productivity of Salmon
Date: Friday, June 14, 2002
Time: 11:00:00 AM
Location: Lecture Theatre
 
SandsNJ, NW Fisheries Science Center, NOAA, Seattle, USA, norma.sands@noaa.gov
Mathisen, O, A, University of Alaska Fairbanks, Juneau, USA, randim@rockisland.com
 
ECOSYSTEM MODELING OF SPECIES INTERACTIONS AFFECTING SOCKEYE SALMON PRODUCTION IN ILIAMNA LAKE, BRISTOL BAY, ALASKA
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Sockeye salmon from Bristol Bay represents a valuable renewable resource, but one that fluctuates greatly. Responsible management requires an understanding of the many factors, other than just spawners, that govern the abundance of returning adult sockeye salmon. Ecosystem modeling of the nursery lake system is used to examine the potential affects of lake species on juvenile sockeye salmon and the importance of adult spawners as both egg producers and contributors of nutrients to the food web. ECOPATH and ECOSIM provide ecosystem models through, first mass balancing in a steady state, and then observing changes in the system under various perturbations of system components. We have used the Iliamna Lake system to model a nursery lake of juvenile sockeye salmon. Species components of the lake have been identified and their trophic level determined from stable isotope analysis. Given the trophic levels, we then used ECOPATH to determine relative abundances under a steady state assumption. ECOSIM was used to study how various components of the ecosystem affect the survival and growth of sockeye juveniles.