Vertical Movement of Walleye in Lake Erie: Ecological and Management Implications

Recent analyses of gill net capture data have characterized walleye as preferring shallow, turbid habitats in Lake Erie, but this does not square with anecdotes of habitat use from the recreational fishery or hydroacoustic surveys.  To address this apparent contradiction, we examined behavioral information on the vertical habitat use of walleye as determined with acoustic telemetry in 2013 and 2014. The goal of this project was to characterize the temporal and geographic changes in the vertical distribution of Lake Erie walleye using pressure-sensing acoustic telemetry tags. Our findings indicated that walleye are strongly oriented towards the bottom of the water column throughout most of the season, and this was corroborated with hydroacoustics surveys. Despite the narrow range of depths which individual walleye utilized, daily vertical migration was apparent and fish tended to be at the top of this range at night. Our results demonstrating bottom orientation complicate annual suspended gill net surveys which are used in population projections and management. Though suspended gill nets were far more efficient than bottom gill nets in the fall, behavioral results from telemetry tags do not yet provide a scenario for this phenomena.