Mercury Elevator in Lakes: A Novel Vector of Methylmercury Transfer to Fish via Migratory Invertebrates

Fisheries in highly productive prairie lakes of Canada and the United States frequently have fish consumption advisories due to elevated mercury concentrations. This occurrence is unexpected because such alkaline lakes often exhibit lower methylmercury (MeHg) concentrations in basal trophic levels than those expected in less productive basins with circumneutral pH. As sources of MeHg to fish are largely dietary, components of the food web are …