Recruitment of walleye pollock in a physically and biologically complex ecosystem: A new perspective

Walleye pollock (Theragra chalcogramma) is a commercially important marine fish in the Gulf of Alaska that has provided a natural experimental system to study many features of the recruitment process. We review recruitment of pollock in the Gulf of Alaska in the conceptual framework of a complex system. In this perspective, high frequency, or activating, events during egg and larval life introduce variability to the dynamics of the population, whereas lower frequency constraining processes tend to promote broader patterns. This view is supported by both simple population and complex statistical models that capture the trends and general patterns in the time series of recruitment. Consequences of this view of recruitment are discussed in terms of forecasting strategies.