Assessing potential barriers to migratory Walleye in the Sandusky River, Ohio.

This article focuses on assessing the impact of the 2018 removal of the Ballville Dam on the Sandusky River, Ohio, regarding migratory passage of Walleye (Sander vitreus) during spawning. Using hydrologic modeling with the Hydrologic Engineering Center's River Analysis System (HEC-RAS) and electrofishing surveys conducted in 2020 and 2021, the study evaluated whether remaining natural and human-made features—such as ice control structures, a limestone shelf, and rapids—create velocity or depth barriers to Walleye migration. Results indicate that while low water depth and high flow velocities can episodically impede passage, Walleye, particularly larger individuals capable of burst swimming speeds, can traverse these barriers under many conditions; this was supported by the capture of Walleye upstream of the former dam site post-removal. The study concludes that dam removal restored fish passage and access to spawning habitat, though selective natural and anthropogenic barriers now influence connectivity, with implications for managing Walleye and other migratory fish species in the Sandusky River basin.