Stock-recruit models for Fraser River Sockeye Salmon (Oncorhynchus nerka) escapement planning

The Larkin stock-recruit model has been used to evaluate long term escapement plans for Fraser Sockeye (Oncorhynchus nerka) since 2006. However, relatively few studies have examined how the Larkin model represents the long term behavior of Fraser Sockeye stocks in comparison to the Ricker stock-recruit model. I identify a representative cyclic Larkin-type, non-cyclic Ricker-type, and undetermined cyclic pattern stock using Deviance Information Criterion. I then compare the bias and precision of parameter estimates using the Ricker and Larkin models and the abundances projected in forward simulations using both models to a historical baseline. My results suggest that the use of stock-specific model forms may be warranted for some stocks and that evaluation of long term escapement plans should focus more on performance measures calculated on the first few generations of forward simulations.