Habitat enhancement for Lake Sturgeon spawning in the Seneca River, NY

Session: Great Lakes Reefs: Research, Monitoring, Creation, and Maintenance (2)

Dawn Dittman, USGS GLSC TLAS, [email protected]
Zy Biesinger, U.S. Fish and Wildlife Service, [email protected]
Marc Chalupnicki, Tunison Lab. of Aquatic Sciences, U.S. Geological Survey, [email protected]

Abstract

Applied restoration ecology addresses the bottlenecks to recovery of threatened species and one of the key bottlenecks for Lake Sturgeon (Acipenser fulvescens) is access to suitable spawning habitat.  New York State has implemented a long-term restoration program (1993-2023) for Lake Sturgeon, including spawning habitat restoration. Habitat quantification (2010-2013) showed limited spawning habitat in the Seneca River, NY.  In fall 2014, three spawning beds equal to 2,000 m² were created in the Seneca River, at the outlet of Cayuga Lake.  Experimental bed placement varied by depth and maximum current.  Lake Sturgeon use of this habitat enhancement was assessed (2015-2018). The reefs’ physical status was evaluated by divers and video analysis.  Mature Lake Sturgeon were captured at the enhancement site each year during spawning season.  Four years after placement, two of the three beds remained largely free of sediment, algae, and mussels. The third bed, built in <3.5m depth and in the slowest current, had few bare rocks or remaining interstitial spaces. These observations give details about how aging of constructed beds may change their effectiveness as high quality habitat.  These results will help refine further design strategies to improve the long-term effectiveness of spawning habitat enhancement for native reef spawning fish.