Sulfate Stimulation of Mercury Methylation In Freshwater Sediments

The relationship between bacterial sulfate reduction and mercury methylation, as well as the in situ distribution of methylmercury in sediments, was studied in Quabbin Reservoir, MA. Fish methylmercury levels in Quabbin and other lakes affected by acid deposition are often elevated. However, the cause of acceleration of net methylmercury production or bioaccumulation in these lakes is poorly understood. Experimental additions of sulfate to either anoxic sediment slurries or lake water above intact sediment cores resulted in increased microbial production of methylmercury from added inorganic mercury