Impacts of climatic change and fishing on Pacific salmon abundance over the past 300 years

The effects of climate variability on Pacific salmon abundance are uncertai n because historical records are short and are complicated by commercial ha rvesting and habitat alteration. We use Lake sediment records of delta N-15 and biological indicators to reconstruct sockeye salmon abundance in the B ristol Bay and Kodiak Island regions of Alaska over the past 300 years. Mar ked shifts in populations occurred over decades during this period, and som e pronounced changes appear to be related to climatic change. Variations in salmon returns due to climate or harvesting can have strong impacts on soc keye nursery Lake productivity in systems where adult salmon carcasses are important nutrient sources.