Studying Mercury Bioaccumulation in Avian Species at the Albany Pine Bush Preserve

Mercury pollution is a concerning phenomenon due to the detrimental effects it can have on natural ecosystems. There have been various studies conducted on the bioaccumulation of mercury in avian species demonstrating reduced reproductive success and changes in standard behavior and endocrine function as a result of the incorporation of mercury into living tissue. In addition to providing an indication of mercury pollution in the region, studying mercury bioaccumulation in birds can provide more knowledge on factors that lead to increased absorption of mercury in organisms.We studied mercury concentration in avian blood and feathers in order to gain a better understanding of the degree of mercury contamination and bioaccumulation process at the Albany Pine Bush Preserve, an inland pine barren in upstate New York. Blood and feather samples were collected from songbird species at the Albany Pine Bush over the course of four years, from 2013 through 2016. The samples were chemically analyzed for their mercury concentrations. We tested several specific hypotheses using separate ANOVAs including whether mercury concentrations varied by year, species, habitat location, diet, or whether the species is a year-round versus breeding-season resident. Blood mercury levels in every sample were below the Biodiversity Research Institute’s lowest risk threshold (<0.7ppm Hg), and they did not vary by year. Although all blood mercury concentrations were classified as being below low risk,  some species, such as Melospiza georgiana (Swamp Sparrow) and Dumetella carolinensis (Grey Catbird), had significantly higher concentrations than others (p<0.0001). Habitat type had a significant effect on mercury concentrations, with wetland birds having two-times higher concentrations than birds that lived in more upland habitats. Overall, we conclude that mercury is not a significant pollutant at Albany Pine Bush and that the preserve is a healthy ecosystem in terms of mercury pollution. The variance in effects of our proposed hypotheses demonstrate that factors such as habitat influence mercury exposure in birds. The study site thus presents favorable mercury values and illustrates a model of positive management that can serve as a comparison for sites with high risk mercury exposure.