MODERN LIMNOLOGICAL RECORDS AND MERCURY CONTAMINATION OF CENTRAL NEW YORK LAKES
Preliminary results from Otisco Lake, a major drinking water supply since the beginning of the 20th century to Onondaga County, show major changes for the past 150 years. Since the 1870s mercury flux increased from around 40 ug/m2/yr to a maximum value of 120 ug/m2/yr during the 1970s. A distinctive increase in mercury flux is observed since the 1930s. In the 1980s the mercury flux reduced to around 90 ug/m2/yr, but rose again in the 1990s. The top most 2 cm of the sediment core from Lake Otisco shows a significant decrease in flux to values below 80 ug/m2/yr. Nutrient flux (carbon and nitrogen) show similar trends that support a connection between changes in land use in the lakes watershed with the mercury flux, suggesting the later is not solely a function of atmospheric deposition. The results contribute to the study of contaminants flux in the modern and pre-industrial periods and their influence on the lakes chemistry. This study can assist in the management of these water bodies, which are used as drinking water supplies and ecological habitats.