Evaluation of management performance of a new state-space model for pink salmon (Oncorhynchus gorbuscha) stock–recruitment analysis

Abstract

A new state space stock –recruitment (SR) model (XSR) was developed to treat observation errors in spawner and catch data, and nonstationarity in productivity for pink salmon ( Oncorhynchus gorbuscha) . Closed loop simulation was used to evaluate the management performance of XSR and compare its performance with that of a traditional SR model (TSR) and a Kalman Filter (KF). XSR produced higher expected catch than TSR and KF over a wide range of conditions. In some situations, TSR was preferred for reducing conservation concerns. However, large “outcome uncertainty” (OU) or implementation error in achieving desired management objectives can substantially reduce the management benefits of all assessment methods. Thus, OU should be considered in all management strategy evaluations, otherwise results will be misleading. Accordingly, reducing OU may better help achieve objectives.