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Ongoing Project:  Cisco assessment in Lake Ontario

Suresh Sethi, Lars Rudstam, Taylor Brown (new MSc/PhD student), Brian Weidel (USGS), (Funded by USGS)

 Species restorations depend on assessments that can determine if population change results from management actions or natural variability.  Great Lakes coregonid restoration actions are advancing rapidly, but are current assessments adequate to determine what is driving coregonid populations? Designing unbiased surveys requires understanding a species’ seasonal and spatial dynamics and their availability to sampling gear.  We argue our current understanding of Great Lakes coregonid life history and habitat use is hampered by contemporary surveys that are seasonally-discrete, inappropriate for target species (ex. bottom trawls rarely catch Cisco), or miss critical habitats (embayments).  Lake Ontario provides a unique setting to evaluate coregonid habitat use dynamics across time and space.  As the smallest Great Lake, whole-lake sampling is most practical. It includes a range of diverse deep and shallow-water habitats used by the Great Lakes coregonids. Quantifying pelagic prey fish habitat dynamics across time and space will provide complimentary, collaborative data for parallel projects on Lake Ontario: coregonid larval spatial dynamics, nutrient dynamic modeling (fish as recyclers) and explaining piscivore behavior.