Project
Genetic and behavioral differences between tributary and lake spawning ecotypes of Lake Whitefish (Coregonus clupeaformis) in Lake Champlain
In recent decades, there have been recruitment failures in many populations of Lake Whitefish (Coregonus clupeaformis) throughout the Laurentian Great Lakes, contributing to declines in stock abundances. In contrast, the Lake Whitefish population in Green Bay, Wisconsin has seen higher than expected population levels and recruitment compared with the rest of Lake Michigan. This corresponds with the first observation of tributary spawning ecotypes in Green Bay in over 100 years. Similarly, managers have observed gravid Lake Whitefish in Lake Champlain tributaries, where there has not been a commercial Lake Whitefish fishery in over a century and a recent study found that the modern population is representative of a fully recovered population. This begs the question whether Lake Whitefish tributary spawning contributes significantly to population growth in both Green Bay and Lake Champlain or is an artifact of the larger population densities in these areas (i.e., the chicken or the egg). Due to the spatial separation between the lake and tributary spawners, these may be two genetically distinct ecotypes that disproportionally contribute to the population. If so, we can use genomic approaches to identify markers that can be used to identify to which ecotype an individual belongs. We can then use these genetic markers to estimate the percent contribution from each ecotype to the mixed stock fishery. In this project we will use both acoustic telemetry and genomics to determine whether Lake Whitefish tributary spawners are a separate ecotype and the contribution from the different ecotypes to the mixed stock fishery.