TRACKING POLLUTION IN NEW YORK STREAMS USING STABLE CARBON AND NITROGEN ISOTOPES

Monitoring water quality and nutrient loading is an important aspect in determining potential sources of pollution, drafting management plans to reduce pollution in the watersheds, and in the long term, evaluating the success of the actions taken. The purpose of this research project focuses on the distribution of stable carbon and nitrogen isotope composition of fluvial systems in order to monitor water quality and nutrient loading in and around the Capital District of New York. Over forty streams have been sampled from various locations around the Schenectady, Schoharie, and Catskills areas. At each site, filamentous algae, micro-invertebrates and water samples were collected. The homogenized samples were analyzed for carbon and nitrogen. Nitrogen and carbon isotopic composition of primary producers and consumers have been used as an indicator of nutrient loading, and as a way to evaluate the effectiveness of sewage upgrades (Costanzo et al., 2005). The analysis of δ¹⁵N values of algae, an indictor for anthropogenic organic pollution, showed urban Schenectady was most affected by pollution. Additionally, the relationship of δ¹³C values present in algae and the alkalinity of the water systems were studied with the expectation to see a clear trend in the results. This study interestingly found the highest alkalinity values were from samples in the Schenectady region. Schoharie sites were lower than expected; we anticipated highest alkalinity values from the Schoharie region due to the presence of limestone bedrock. With additional site data and analysis these trends in the results can be better understood.