Fish Community Threshold Response Associated With Coal and Mineral Mines in Catchments

Mining is a small portion of United States’ (US) land use (~1%), but its disturbance leaves an ecological footprint that influences a catchment for decades. We used the National Fish Habitat Partnership spatial and analytical framework for inland assessment (Wang et al. 2011, Esselman et al. 2013) to evaluate impacts of mineral mines, processing plants, and a new coal mines point layer (n=167,979 total US) on fish communities in three large ecoregions. We a priori selected ten fish community metrics (intolerant, lithophilic, piscivore, etc.) to evaluate mine density (#/km2) influences at two scales (local and network catchments). In an effort to provide a rigorous analytical process for detecting community thresholds, we used two threshold detection methods: change-point analysis with indicator analysis and piecewise linear regression. We accepted only the thresholds that were analogous and highly significant from the two techniques. Majority of the thresholds demonstrated that mines at any density within the watershed (local or network) caused a community threshold response at the low range of the gradient. Compared to other anthropogenic disturbances previously assessed at these scales such as agriculture, impervious surface, or urban land use, mining has a more pronounced and consistent impact on the community of fishes.