WHEN RIVERS COLLIDE: DO MICROBIOMES REDUCE SUBCATCHMENT STRESSORS AND IMPROVE ECOSYSTEM RESILIENCE IN A MODEL REGULATED APPALACHIAN RIVER?

River ecosystems are particularly vulnerable to damage through both well-intended regulation that alters natural hydrological processes and land-use impacts arising from regional and local watershed damage. Individual subcatchments can contribute quite different stressors including agricultural residues, municipal wastewater, industrial chemicals, and urban runoff that mix through river mergers. Rivers are therefore a focal point for eclectic combinations of stressors resulting in ecosystem outcomes that are difficult to predict. Furthermore, riverine microbiomes which have incredible metabolic diversity undoubtedly make substantial, but still poorly understood, contributions to the synergistic or antagonistic outcomes of stressor combinations. The overall research goal is to investigate the effects of combined stressors found in the Kanawha River watershed. This large watershed (31,000 square km) lies in the Central Appalachian Mountains and encompasses 75% forest, 13% agricultural land and 6% developed land. The region also contains extensive Mountaintop Mining and Valley Fills that severely damage headwater streams. The types of subcatchment stressors represent agricultural residues (pesticides and fertilizer), municipal inputs (waste water effluent), industrial wastes, and coal mining residues. The objectives of this research are: 1) Evaluate the effects of multiple stressors and engineered remediation on water and sediment chemistry, water quality, and river metabolism in the Kanawha River watershed, 2) Measure riverine microbiome functions and diversity along disturbance gradients arising from subcatchment mergers to test if local metabolic functions alter riverine ecosystem services, 3) Test whether multiple simultaneous chemical stressors have synergistic or antagonistic effects on microbiome bioremediation using time series analysis of sediment microbiomes, 4) Create predictive models that integrate hydrology, water chemistry and microbiome diversity following the merger of subcatchment rivers. Capacity in both research and education will be built at WVSU in the areas of environmental and freshwater science, biotechnology and microbiome analysis.