New modeling framework evaluates vulnerability of freshwater species

A research team led by Dr. Clint Muhlfeld, USGS, and Dr. Erin Landguth, University of Montana, has developed a new modeling simulation framework to help guide the management of freshwater species in the face of climate change and other cumulative stressors. The modeling framework combines genetic and demographic characteristics with environmental variables to predict how future stream warming may influence aquatic populations.

In a pilot study, the team applies the framework to migratory bull trout populations and demonstrates that habitat fragmentation, caused by warmer water temperatures and barriers to fish movement, results in a loss of genetic diversity and a reduction in numbers. The researchers state that this “demogenetic” framework is useful to evaluate population vulnerability of freshwater species in a variety of riverscapes.


Example of a riverscape

An example riverscape with 19 subpopulations and 50 individuals per subpopulation. Left inset shows a spawning bed with 50 individual locations, right inset shows the riverscape with varying degrees of resistance values assigned to each pixel value in the stream network. The "Lake Source" is Flathead Lake, MT, to which species that have a migratory life history (e.g., bull trout) will migrate.


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This research was supported by the Great Northern Landscape Conservation Cooperative and Northwest Climate Science Center.