The influence of changing climate on the ecology and management of Great Lakes fisheries

The Great Lakes provides an excellent ecological system to evaluate the potential effects of climate change on fish populations and the management of their fisheries.  We describe select physical and biological mechanisms which will affect fish populations with projected climate change in the Basin.   The regional climate is predicted to be warmer, with increased precipitation and a reduction in the extent and duration of ice cover.  We use case studies of lake whitefish (Coregonus clupeaformis), walleye (Sander vitreus), and smallmouth bass (Micropterus dolomieu) to examine the potential effects of climate change on Great Lakes cold, cool, and warm water fishes.  Additionally, we modeled population changes (i.e., distribution and abundance) for the sensitive cold water species, lake whitefish, with projected climate processes and discuss ecosystem-level implications with this species, its production, and the management of its fisheries. Overall, the projections are for warm water species to extend their range northward thereby increasing their abundance and overall productivity while cold water species will experience range contraction and less overall productivity given loss of suitable habitat. These projections, if realized, will challenge the flexibility of our current fisheries programs and require setting adaptive management expectations for a sustainable future for Great Lakes fisheries.