Master of Science (MS), Ohio University, 2016, Plant Biology (Arts and Sciences)

Acid Mine Drainage (AMD) from pre-regulation mining affects streams in the Appalachian region resulting in acidic waters with high dissolved metal content. Previous studies have shown remediated stream segments have better water quality and biological communities than untreated streams, but these segments have not attained the same biological quality as streams unaffected by AMD. Phosphorus limitation of the biofilm community has been hypothesized as a contributing factor. Nutrient limitation was tested in four stream categories using nutrient diffusing substrates: AMD, transitional, recovered and unimpacted. Chlorophyll a, a measure of photosynthetic biomass, was significantly higher in phosphorus treatments. In addition, the phosphorus treatments had lower phosphorus-acquiring enzyme activities compared to the control. The phosphorus with nitrogen treatment showed an increase in polyunsaturated fatty acids, having higher nutritional value for grazers. This study demonstrated that nutrient availability has a substantial impact on the photosynthetic component of biofilms in impaired and remediated streams.

Committee: Morgan Vis (Advisor); Jared DeForest (Committee Member); Kelly Johnson (Committee Member) Subjects: Ecology; Freshwater Ecology