A paleolimnological record from Lake George, NY: implications of drought susceptibility and eutrophication

Wiltse B & Stager JC. 2009. A paleolimnological record from Lake George, NY: implications of drought susceptibility and eutrophication. The Annual Conference on The Adirondacks, Adirondack Research Consortium, Lake Placid, NY USA.

Knowing the history of an ecosystem is an important key to understanding its modern condition and vulnerability to future changes, and paleolimnology can often provide historical perspectives necessary for understanding and protecting aquatic ecosystems. In this study a 30cm sediment core taken from the north basin of Lake George was analyzed for changes in diatom community structure. The chronology of these sediments was established using radioisotopic dating methods. A unique and interesting sedimentary profile was observed while retrieving cores throughout the north basin of the lake. The nature of this sedimentary profile, along with supporting evidence from the diatom community, strongly suggests that a low stand occurred in the lake sometime between 200-350 BP. The low stand likely predated settlement of the watershed and would have resulted in a several meter drop in lake level. It is possible the lake was rebounding from this low stand as the watershed was being settled. Evidence of the recent onset of cultural eutrophication was also observed in the diatom community structure. The timing of this changed occurred in the early 20th century and is probably related to development within the watershed. These findings highlight the importance of monitoring and predicting hydrological conditions in the Lake George watershed as human-driven climate change complicates the natural range of rainfall and drought variability in the region. They also provide a context for understanding the current state of the lake and understanding the degree of anthropogenic impacts on the watershed.