MODELING THE LINKAGES BETWEEN FLOW MANAGEMENT AND SALMON RECRUITMENT IN RIVERS

We developed a simulation model to predict instream flow effects on sm elt production for fall chinook salmon (Oncorhynchus tshawytscha) in r egulated rivers. The principal purpose of this model is to serve as a management tool to evaluate effects on salmon of instream releases fro m upstream reservoirs. The dramatic decline in chinook salmon in Calif ornia rivers suggests a need for such a tool. We developed an individu al-based and spatially explicit model to simulate the influences of ri verine habitat on each lifestage leading to successful outmigration of chinook salmon. Model predictions of development, growth and survival showed good agreement with four years of field data collected on the Tuolumne River, California. Our analysis of parameter sensitivities id entified flow-related redd mortality and temperature-related juvenile mortality as limitations on smelt production. (C) 1997 Elsevier Scienc e B.V.