Sockeye Salmon Overescapement (Kenai River Component). EXXON VALDEZ Oil Spill Restoration Project Final Report

摘要

The 1989 Exxon Valdez oil spill in Prince William Sound resulted in many commercial fishery closures, which led to significantly higher than normal escapements in some sockeye salmon systems. For the Kenai River (south-central Alaska), the number of sockeye salmon returning to spawn that year was twice the recommended escapement goal. A weak positive relationship existed between abundance and the number of sockeye fry rearing in the fall in glacially turbid Skilak and Kenai lakes during the fall. The variability of total copepod biomass in the spring (May-June), coupled with abundance of adult spawners, provided a much higher degree of predictability of fall fry production. In addition, grazing by juvenile sockeye on cyclopoid copepods in the spring strongly influenced recruitment of the next generation of juvenile sockeye salmon.