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Assessment of Mercury in Waters, Sediment and Biota of New Hampshire and Vermont Lakes Using a Geographically Randomized Design
Neil C. Kamman, Peter M. Lorey, Charles T. Driscoll, Bob Estabrook, Drew Major, Bernie Pientka, Ed Glassford.
VT Department of Environmental Conservation 103 S Main 10N Waterbury VT
05671-0408 (802) 241-3795 (tel) (802) 241-3287 (fax)
In response to a growing need for detailed information regarding mercury in the New England region, an assessment of Hg in waters, sediments, and biota of Vermont and New Hampshire lakes was made during the period 1998-2000. Lakes were selected for sampling following USEPA regional environmental monitoring and assessment program protocols. Ninety-three lakes were sampled for mercury, methylmercury and ancillary parameters in epilimnetic and hypolimnetic waters, and in sediments. Yellow perch (Perca flavescens) muscle tissue from study lakes containing perch were also analyzed for mercury. The resultant dataset was opportunistically analyzed using multivariate techniques. Aqueous total and methylmercury concentrations were elevated in dystrophic and eutrophic lakes. Perch tissue concentrations were elevated by approximately 0.218 mg g -1 in dystrophic lakes over remaining waterbody types, and were very low in eutrophic lakes. Principal components analysis indicated that while total and methylmercury increased in response to increasing lake acidity and productivity, tissue mercury concentrations only increased with increasing acidity. A set of linear discriminant models, developed to estimate whether lakes would exhibit fish tissue mercury concentrations in excess of the current USEPA 0.3 mg g-1 fish tissue methylmercury criterion, indicated that age-adjusted yellow perch tissue in 40.2% (+/- 13%) of lakes exceed the criterion. Based on this model, lakes in New Hampshire were twice as likely to exhibit criterion violations as Vermont lakes. The dataset produced in conjunction with this study can provide useful information to target additional assessments to refine tissue consumption advisories, and serves as a baseline against which the success of future reductions in atmospheric mercury deposition can be assessed.
Keywords: Biodilution, Fish tissue, Mercury, Water, Watershed