Hypolimnetic methylmercury and its uptake by plankton during fall destratification: A key entry point of mercury into lake food chains?

摘要: Seasonal concentration changes in monomethylmercury (MMHg) and total Hg (T-Hg) were determined Devil's Lake, Wisconsin, a lake with mercury consumption advisory for walleye. Mercury dynamics studied water several lower food chain fractions during the ice-free seasons 1994 1995, limited data collected 1993. MMHg concentrations increased hypolimnetic waters before turnover each year, although maximum declined from 1993 to 1995. As hypolimnion eroded, both particulate matter Daphnia. Maximum obtained near time of complete mixis. The magnitude this increase correlated mass that had built up prior yearling planktivorous fish exhibited decline corresponding Our results suggest fall destratification represents an important period entry lakes exhibiting buildup.