The accumulation of elevated levels of mercury (Hg) in fishes and wildlife is of concern for the Florida Everglades, a subtropical freshwater wetland ecosystem (Ware et al. 1990). Since the detection of elevated Hg concentrations in Everglades fish and wildlife, continuous efforts have been made to investigate the source (Guentzel et al. 2001), transport (Zhang and Lindberg 2000; Drexel et al. 2002; Liu et al. 2008b; Liu et al. 2008c; Liu et al. 2009), transformation (e.g., reduction/oxidation and in particular methylation/demethylation) (Gilmour et al. 1998; Hurley et al. 1998; Marvin-DiPasquale and Oremland 1998; Cleckner et al. 1999; Li et al. 2010), and bioaccumulation of Hg (Cleckner et al. 1998; Loftus 2000) in the Everglades. These studies have signifi cantly advanced our understanding of Hg biogeochemical cycling in this wetland ecosystem.