SIMULATED GROWTH AND PRODUCTION OF ENDANGERED SNAKE-RIVER SOCKEYE-SALMON - ASSESSING MANAGEMENT STRATEGIES FOR THE NURSERY LAKES

We examined the potential of employing a series of lake management str ategies to enhance production of endangered Snake River sockeye salmon (Oncorhynchus nerka) in its historical nursery lakes in central Idaho . We used a combination of limnological sampling, experimentation, and simulation modeling to assess effects of lake fertilization and kokan ee reduction on growth and survival of juvenile sockeye salmon. Juveni le sockeye salmon from a broodstock of this endangered species are bei ng introduced into the lakes from 1995 to 1998. Results of our analyse s indicated that several lakes were suitable for receiving broodstock progeny. Field experimentation and simulation modeling indicated that lake fertilization, coupled with a program of kokanee reduction, provi ded the management option most likely to enhance the survival of stock ed juvenile sockeye salmon. Simulation models that encompass physiolog ical requirements, ecological interactions, and life-history consequen ces could be used as templates to help develop recovery plans for othe r endangered fishes.