Abstract by Nathan Gunnell
Isotopic Analysis of the Anthropogenic Impact in Farmington Bay
Influence of human activity on surrounding environments is an important field of research. With respect to aquatic settings, lacustrine deposits provide excellent proxies of environmental change since the sediment accumulates at a relatively constant rate, recording environmental change. This study employs isotopic records from Farmington Bay freeze cores, in particular delta13C, delta15N, and 210Pb isotopes. In particular, delta15N provides a record of changing nutrient sources and 210Pb isotopes permit estimation of the age of sediment with depth.
Initial results from these 210Pb isotopes have allowed ages to be assigned to depths along the core extending back roughly 100 years at 30 cm. At this depth, a dramatic shift in the delta15N isotopes is observed. Initial delta15N levels indicated a nutrient source related to agriculture. However, beginning around 100 years ago, the delta15N shows the main nutrient source for the bay became wastewater. This may have been a result of the completion of a sewage canal in 1911 which began routing wastewater directly into the bay.