Growth and Mortality of Walleye in Select New York Waters 1991–2010

Elaine Langone Center, Terrace Room

Walleye (Sander vitreus) is a popular sportfish in North America and is actively managed to support fisheries throughout New York State (NYS). Successful recruitment in most fish populations is strongly linked to survival and growth of a typically vulnerable young of year class. The ability to quantify survival and growth of stocked fish in particular has the potential to enhance ongoing management efforts and better predict changes in population dynamics. However, estimation of growth parameters is often difficult in data-limited populations. We used Bayesian hierarchical methods to fit von Bertalanffy growth models to length-at-age data for walleye collected from various waters in southeastern NYS. This approach allowed us to share information across walleye populations to estimate growth parameters and total annual mortality in waters sampled by state biologists 1991–2010. The model also provides region-wide estimates of life-history parameters. Walleye growth rates (k) were similar between waterbodies, but maximum size of walleye caught was notably smaller in Canadarago Lake than in other lakes. On a regional scale, average annual mortality for walleye was 0.41(95% CRI: 0.32–0.50), as estimated from life-history invariants. Future work on Percids in this region will investigate number of factors that influence length at age.