Background Fluvial fish habitat in the Northeastern and Midwestern U.S. is substantially affected by natural landscape factors and anthropogenic stressors, with climate change expected to alter natural influences and ...Background Fluvial fish habitat in the Northeastern and Midwestern U.S. is substantially affected by natural landscape factors and anthropogenic stressors, with climate change expected to alter natural influences and exacerbate stressor effects. To conserve fluvial fish species in the future, it is crucial to understand which fish habitats will be most strongly influenced by changing climate, which species are most sensitive to climate change, and how changes in individual species will affect entire assemblages. To answer these questions, we modeled fluvial fish distributions under projected changes in climate to understand how climate could affect suitability of fish habitat for 55 widely distributed fluvial fishes with differing thermal preferences in the region. Using boosted regression tree models, we predicted distributions of fishes at a stream reach scale using four contemporary climate variables including annual mean air temperature, annual precipitation, and variation in monthly air temperature and precipitation along with seven natural landscape and anthropogenic stressor variables. We then used projected values from eight general circulation models(GCMs) during 2041–2080 to evaluate potential patterns in species richness, turnover, and range shifts under climate change across the study region.Results Most cold-water and cool-water species were projected to lose habitat;however, projected habitat loss also occurred for certain small-bodied warm-water species. The percentage change in species richness of all 55 species across reaches ranged from-40.4 to 33.93%, with regions of major species richness losses occurring across southern portions of the Northeastern coast and southern Midwest regions. Species turnover ranged from 0 to 43.5% with substantial turnover occurring along the Northeastern coast and upper Midwest.Conclusions Temperature and precipitation variation will influence fish species distribution substantially. Our findings provide multiple measures describing patterns of fish community change under climate change to aid management and conservation of stream fishes in the future.展开更多
基金funded by the United States Geological Survey Aquatic GAP Project
文摘Background Fluvial fish habitat in the Northeastern and Midwestern U.S. is substantially affected by natural landscape factors and anthropogenic stressors, with climate change expected to alter natural influences and exacerbate stressor effects. To conserve fluvial fish species in the future, it is crucial to understand which fish habitats will be most strongly influenced by changing climate, which species are most sensitive to climate change, and how changes in individual species will affect entire assemblages. To answer these questions, we modeled fluvial fish distributions under projected changes in climate to understand how climate could affect suitability of fish habitat for 55 widely distributed fluvial fishes with differing thermal preferences in the region. Using boosted regression tree models, we predicted distributions of fishes at a stream reach scale using four contemporary climate variables including annual mean air temperature, annual precipitation, and variation in monthly air temperature and precipitation along with seven natural landscape and anthropogenic stressor variables. We then used projected values from eight general circulation models(GCMs) during 2041–2080 to evaluate potential patterns in species richness, turnover, and range shifts under climate change across the study region.Results Most cold-water and cool-water species were projected to lose habitat;however, projected habitat loss also occurred for certain small-bodied warm-water species. The percentage change in species richness of all 55 species across reaches ranged from-40.4 to 33.93%, with regions of major species richness losses occurring across southern portions of the Northeastern coast and southern Midwest regions. Species turnover ranged from 0 to 43.5% with substantial turnover occurring along the Northeastern coast and upper Midwest.Conclusions Temperature and precipitation variation will influence fish species distribution substantially. Our findings provide multiple measures describing patterns of fish community change under climate change to aid management and conservation of stream fishes in the future.
