Annual Technical Report, FY 2003: Maine
Bank MS, Loftin C, Amirbahman A. 2003. Annual Technical Report, FY 2003: Maine. U.S. Geological Survey. Water Research Institute
Mercury (Hg) contamination in the northeastern United States, including Acadia National Park (ANP), is well documented and continues to be a public-health issue of great concern. Hg contamination of wild amphibians has received little attention despite mounting evidence and reports of worldwide population declines. This report defines total Hg and methyl Hg concentrations for water, sediment, and green frog and bullfrog tadpoles (~ 1 year of age) from ANP. Average total Hg concentrations in green frog and bullfrog tadpoles were 25.1+1.5 and 19.1+0.8 Hg ng/g wet wt, respectively. Methyl Hg comprised 7.6-40% of the total Hg in tadpole tissue, and average total Hg levels in tadpoles were significantly different among pond sites. Total Hg in pond water was a significant predictor of tadpole total Hg levels. Dissolved organic carbon was a significant predictor of both total Hg and Methyl Hg in water, and total Hg in water was also strongly correlated with Methyl Hg in water. The methylation efficiency (ME) rates defined as total Hg:Methyl Hg ratio in pond waters sampled at ANP were higher than the reported ME for national parks located in the western region of the United States. Of the ponds sampled at ANP, 44% had ME greater than 10% suggesting that wetland food webs in the park are likely susceptible to high levels of total Hg bioaccumulation.