Historic coregonine habitat use and assessment of larval nursery locations in Lake Erie

Coregonine fishes (Coregonus spp.) are important components of Great Lake food webs and support lucrative commercial and recreational fisheries. Due to a combination of several factors including habitat loss, over-exploitation, and introduction of exotic species, the distribution and abundance of coregonines have been reduced. Examples of these declines are evident in Lake Erie where cisco (C. artedi) have been nearly extirpated, and lake whitefish (C. clupeaformis), while still abundant, are declining. To identify key habitat locations of coregonines in Lake Erie, we conducted a literature review of historical spawning, nursery, and adult habitat sites where coregonines have been observed. We used these sites as a reference for larval sampling at six locations across the southern shore of Lake Erie during spring 2017. Paired bongo samplers were used to collect larvae, and average densities were calculated for comparison across sites. Larval coregonine (46 visually identified as lake whitefish; 8 classified as coregonines) densities were highest at Huron, OH (0.880/1,000 m3 ± 1.61), followed by Sandusky, OH (0.426/1,000 m3 ± 1.05), Dunkirk, NY (0.208/1,000 m3 ± 0.703), Fairport, OH (0.185/1,000 m3 ± 0.680), Erie, PA (0.120/1,000 m3 ± 0.532), and Conneaut, OH (0.1196/1,000 m3 ± 0.528). Using contemporary sampling data coupled with historical spawning locations, we identified sites that are currently being used as nursery locations by lake whitefish. By validating the contemporary use of historic spawning and nursery sites, this study identifies locations where habitat protection and restoration or future stocking of coregonids could be conducted in Lake Erie in efforts to recover populations and improve fishery production.