In situ studies with asian clams (Corbicula fluminea) detect acid mine drainage and nutrient inputs in low-order streams

In situ Asian clam (Corbicula fluminea [Müller]) studies may effectively mirror resident community responses to both acute toxicants and nutrient inputs in low-order streams. Clam survival and growth after 30 days in situ were compared with benthic macroinvertebrate community structural changes caused by acid mine drainage (AMD) and nutrient loading (measured as nitrate) in a small subwatershed of the North Fork Powell River, Virginia, U.S.A. Clam survival distinguished between two different levels of impact due to acidic, neutralized, and intermittent AMD inputs and was positively correlated with water column pH and negatively correlated with conductivity and metal concentrations. Survival was also positively correlated with relative abundance of the order Ephemeroptera, the most sensitive macroinvertebrate taxonomic group to AMD in this system. Clam growth was not related to AMD inputs but was positively correlated with nitrate concentrations and the relative abundance of the collector-filterer functional feeding group. These results suggest that transplanted clam studies accurately reflect benthic macroinvertebrate community responses to multiple stressors from point and nonpoint sources.