Lake management in a warming climate: 3D modeling of fish habitat

Shahram Missaghi, Associate Extension Professor, University of Minnesota

Our lakes are changing and we should also change how we manage them.  Lakes are susceptible to land use and their management has traditionally focused on managing the upland (watershed) with what runoff brings into the lakes.  However, climate change has exacerbated the lake’s responses to anthropogenic inputs. In this seminar, I will discuss the influence of climate change on lake thermal structure and will present the results of our recent research on the temporal and spatial variability of water quality.  We will report the fine-scale 3D changes in water quality parameters that define coolwater fish habitat in a Minnesota lake. Results showed that thermocline depth increased 64%, and the onset of stratification and anoxia occurred 46 days and 4 weeks earlier under a warmer future climate scenario.  In the same scenario, the desirable fish habitat was also separated for three weeks in July by the lethal fish habitat, leaving the coolwater fish with no potential refuge (note the expanded red area in the very warm future scenario).  Lastly, we will present that fine-scale 3D spatial and temporal forecasting of potential stressed fish habitats are essential in any future lake management.