Twin Cities WRS Seminar

Simulated Coolwater Fish Response to Lake Warming


Dr. Shahram Missaghi
University of Minnesota Extension

September 22, 2017


The application of a three-dimensional computer model proved essential in revealing the influence of a predicted warming climate on fish habitat in a local lake.  Computer models, particularly the one-dimensional models, have been key in advancing our understanding of potential impacts of climate change on our lake ecosystems.  Nonetheless, the three-dimensional computer models have the feature of reproducing the complex ecological processes of a lake at such a fine scales (temporal and spatial) that could further enhance our understanding and increase our ability to better predict the potential future changes.  The presentation will start with a brief discussion on zero, 1, 2, and 3-dimensional computer models and their utility.   Three climate change scenarios were developed to evaluate the changes of water temperature (T)  and dissolved oxygen (DO) - the key water quality parameters to evaluate the changes in coolwater fish habitat.  T increased 4 °C and DO decreases 1 mgL-1 during the ice-free seasons under the future climate scenarios with the onset of stratification increased 46 days, thermocline depth increased 64%, and the onset of anoxia occurs 4 weeks earlier.  The predicted desirable good growth fish habitat was separated for three weeks in July by the lethal fish habitat, leaving the coolwater fish with no potential refuge.  The fine scale spatial and temporal prediction of stressed aquatic conditions is becoming essential in water resources and ecological management.

Shahram Missaghi develops research-based water resources education programs that promote innovative practices to reduce the environmental impacts of excessive stormwater runoff.  He has a PhD in Water Resources Science (Limnology and Oceanography) and conducts research in ecological modeling and climate change impacts on water resources.