Cooperative Fish and Wildlife Research Units Program: Wisconsin Fishery
Education, Research and Technical Assistance for Managing Our Natural Resources

Lake whitefish recruitment has declined in several management zones around the Great Lakes, yet recruitment has markedly increased in southern Green Bay following a resurgence of spawning in some tributaries. This progression seems to suggest that restoring tributary spawning might help offset declines in whitefish recruitment in other areas. However, assuming that tributary spawning is primarily responsible for the expansion of lake whitefish in southern Green Bay is purely speculative. In reality, the importance of tributary spawning to the lake whitefish stock in southern Green Bay remains unknown and available evidence (e.g., telemetry, larval sampling) suggests that whitefish also spawn outside of tributaries at locations that have yet to be identified, representing a major obstacle in understanding stock dynamics. This project is a collaboration of researchers across multiple agencies and includes the Wisconsin Department of Natural Resources, Michigan State-Hammond Bay Biological Station, Fish and Wildlife Service, and the Great Lakes Acoustic Telemetry Observation System. If most whitefish in southern Green Bay spawn in tributaries, restoring this spawning strategy might provide a viable management tool in other places. Conversely, if a relatively low proportion of lake whitefish in southern Green Bay spawn in tributaries, restoring river spawning may be less likely to offset population declines in other portions of the Great Lakes.