“…Determining the environmental factors responsible for mercury levels observed within organisms remains elusive although several key parameters have been correlated with high mercury or methylmercury levels in fish. For example, increasing trophic position (Spry and Weiner, 1991;Jackson, 1998), body size (Scott and Armstrong, 1972;Scott, 1974;Wren et al, 1983), age (Simonin et al, 1994), dissolved organic carbon (DOC) concentration (Driscoll et al, 1995;Wiener and Spry, 1996), pH (Cope et al, 1990;Grieb et al, 1990;Haines et al, 1992), food web complexity (Futter, 1994;Wong et al, 1997;Chen et al, 2000), degree of flooding (Jackson, 1991;Johnston et al, 1991;McNicol et al, 1997), and percent of watershed with wetland habitats (Jackson, 1988;McMurty et al, 1989), have all been variously associated with mercury levels in fish or fish-eating birds and mammals.…”