Evaluating Changes in Habitat of Warm-Water Fishes with Changes in Climate over Large Regions: Using an Ecological Classification to Identify Susceptible Habitats

Changing climate will affect stream habitats and fishes they support throughout the U.S.  While cold water fishes have been the focus of many studies, less attention has been given to warm water fishes.  Our study identifies hydrological and thermal stream characteristics important to warm water fishes and assesses how they may change with climate in large regions of the U.S.  We achieved this by using quantitative analyses to establish linkages among climate, habitat, and abundances of warm water fishes identified from literature by thermal preferences. We first identified associations between hydrological and thermal characteristics of stream habitats and fishes, and then identified climatic factors strongly associated with habitat characteristics important to fishes.  Next, we developed an ecological classification of stream reaches that included important climate metrics and other landscape factors.  Projected climate variables were substituted into resulting classes to identify streams anticipated to change with climate.  Results show locations likely to change throughout our large study regions, and mechanisms of change may be identified via our spatially-explicit process.  Managers interested in broad effects of changing climate on warm water fishes can use our results to identify protection and restoration opportunities, including identifying appropriate actions to best conserve.