Development of a Stock–Recruitment Model and Assessment of Biological Reference Points for the Lake Erie Walleye Fishery

Abstract

We developed an updated stock–recruitment relationship for Lake Erie Walleye Sander vitreus using the Akaike information criterion model selection approach. Our best stock–recruitment relationship was a Ricker spawner–recruit function to which spring warming rate was added as an environmental variable, and this regression model explained 39% of the variability in Walleye recruitment over the 1978 through 2006 year-classes. Thus, most of the variability in Lake Erie Walleye recruitment appeared to be attributable to factors other than spawning stock size and spring warming rate. The abundance of age-0 Gizzard Shad Dorosoma cepedianum, which was an important term in previous models, may still be an important factor for Walleye recruitment, but poorer ability to monitor Gizzard Shad since the late 1990s could have led to that term failing to appear in our best model. Secondly, we used numerical simulation to demonstrate how to use the stock recruitment relationship to characterize the population dynamics (such as stable age structure, carrying capacity, and maximum sustainable yield) and some biological reference points (such as fishing rates at different important biomass or harvest levels) for an age-structured population in a deterministic way.

Received September 21, 2012; accepted July 2, 2013

ACKNOWLEDGMENTS

We thank the Lake Erie Committee's Walleye Task Group and Forage Task Group for providing data and for supporting this research. Water temperature data were provided by G. Dunmore of the Ontario Clean Water Agency. C. Vandergoot, A. Cook, and three anonymous reviewers provided constructive reviews. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government or Canadian Government. This article is contribution 1778 of the U.S. Geological Survey, Great Lakes Science Center.