Fig. 2. Organic matter and methylmercury (MeHg) (open bars) as well as pH and total Hg (closed bars) in wetlands found on different lithologies. Closed circles indicate acid volatile sulfide or surface complexation model estimate of percentage of total Hg sorbed to bacteria in different lithologies. Note the 1000-fold difference in the scales for MeHg and Hg. Error bars indicate standard error of the estimate.