Paleolimnology of Onondaga Lake: the History of Anthropogenic Impacts on Water Quality

Abstract

ABSTRACT New York State's Onondaga Lake is a polluted, hypereutrophic, saline lake with a remarkable paleolimnological record. The chemical and diatom stratigraphy of two sediment cores was used to document past anthropogenic impacts on the lake's water quality. Onondaga Lake's pre-historic and pre-industrial water quality conditions are clarified and subsequent major pollution events identified. Pre-1800s Onondaga Lake was mesotrophic and considerably less saline (around 230 mgL−1 Cl−) than at present (around 450 mgL−1 Cl−). Factors that most affected lake water quality were: 1) increasing settlement in the watershed which increased lake sedimentation and nutrient levels, 2) development of the salt industry during the 1800s which contributed to a rise in lake salinity, 3) the soda-ash industry in die late 1800s through 1900s which added major amounts of CaCO3 and salt to the lake, and 4) post-World War II urban and industrial development which contributed to very high nutrient, Hg, and other heavy metal loadings.