UW Aquatic & Fishery Sciences Quantitative Seminar

Tim Walsworth

School of Aquatic and Fishery Sciences, University of Washington

Effects of fishery structure and predation on productivity of an Alaskan sockeye salmon fishery

Abstract

There are increasing calls for fisheries management systems to shift towards a more ecosystem based approach to management, accounting for effects of fishery activities on species interactions, as well as species interactions on fishery dynamics. The Chignik Lakes watershed on the Alaska Peninsula supports valuable sockeye salmon fishery, as well as populations of coho salmon that are not directly targeted for harvest. While not economically valuable, coho salmon play an important ecological role in the system as juvenile coho salmon have been estimated to consume over half of the emerging sockeye salmon fry each year. As such, the current asymmetric harvesting strategy may be limiting ultimate productivity of the sockeye salmon fishery. Here, I present simulation model results examining the ability to detect an effect of coho salmon predation on sockeye productivity, and on the potential effects of alternative harvest strategies on the harvest and revenue of the Chignik salmon fishery.