Exploring the effects of chemical fragmentation in Central Appalachian streams

Background/Question/Methods

Mountaintop removal coal mining has cleared over 0.5 million hectares of Appalachian forests and has buried 4,000 km of headwaters, streams which disproportionately contribute to high regional aquatic biodiversity. Recent work in West Virginia has indicated that as much as 32% of the river network is biologically impaired due to the cumulative export of ionic solutes that extirpate sensitive taxa far downstream of directly impacted headwaters. However, many headwaters without direct impact from mining may be isolated from the river network by downstream chemical pollution.  Using comprehensive maps of mining activity and macroinvertebrate data covering southwest West Virginia, we explore the extent to which such chemical fragmentation occurs and whether that fragmentation alters macroinvertebrate community composition. 

Results/Conclusions

We quantify the extent of chemical fragmentation using several metrics calculated from a regional landscape analysis of mining and find that chemical fragmentation is a common feature across many large river basins in our study area. Then by overlaying these chemical fragmentation proxies onto ordinations of the macroinvertebrate assemblage data, we find that these proxies weakly correlate (r = 0.25-0.33) with macroinvertebrate community structure in headwaters otherwise unimpacted by mining.