Status of Recruitment Studies of Northeast Pacific Fishes
Bulletin of the Sea Fisheries Institute 3 (151) 2000, pp. 21-42

Arthur W. Kendall, Jr.
Alaska Fisheries Science Center, Seattle, WA 98115, USA

Key words: walleye pollock, Bering Sea, Gulf of Alaska, year-class strength, climate change, FOCI, Johan Hjort.

Abstract.
Recruitment research is vital to fisheries management, since year-class strength is the most significant biological variable affecting abundance of high latitude fish populations. Year-class strength is usually not well correlated with spawning stock size or environmental variables. Variable survival of early life stages (eggs and larvae) is critical in determining year-class size.  The recruitment problem has a long history in fisheries research and its study continues today.  The history of such studies in the temperate and subarctic northeast Pacific are traced back to work on Pacific halibut by W. F. Thompson and others. With the discovery in 1980 of a concentrated spawning aggregation of walleye pollock in Shelikof Strait, Gulf of Alaska, recruitment research found a focus that led to expanded studies there and in the Bering Sea. This research has led to annual forecasts of relative year-class strength that help guide management of pollock harvests.  In the future, more emphasis needs to be placed on time-scales other than interannual and ecosystem responses such as system productivity, changes in species dominance, and system maturity. This emphasis will require complex long-term and multi-trophic level studies.