Factors Affecting Mercury Accumulation in Fish in the Upper Michigan Peninsula

Concentrations and Hazard Assessment of Organochlorine Contaminants and Mercury in Smallmouth Bass from a Remote Lake in the Upper Peninsula of Michigan

“…The similarity in organochlorine concentrations between fish from Fumee Lake and Lake Superior was expected because atmospheric deposition is thought to be the primary source of contaminants to Lake Superior (Eisenreich et al 1979). Mercury concentrations in smallmouth bass from Fumee Lake were comparable to those reported for several species of fish from inland lakes in Michigan and Wisconsin (Grieb et al 1990). The average mercury concentration in Fumee Lake smallmouth bass (221 ng/g wet wt) was comparable to that of the national mean value of 260 ng/g wet wt (Bahnick et al 1994).…”

“…Mercury concentrations were not linearly correlated with fish weight (Figure 3). While several studies have reported positive correlations between mercury concentrations and fish length or weight (Grieb et al 1990;Sorensen et al 1990;Gutenmann et al 1992;Lange et al 1994;Kannan et al 1997), a few studies have found no correlation (Cope et al 1990;Driscoll et al 1994). Lower mercury concentrations in older, faster-growing perch or trout have been attributed to growth dilution, in which the rate of tissue elaboration exceeds the rate of mercury accumulation (Driscoll et al 1994;Kim 1995).…”

“…Although a great deal of effort has been expended studying the fate and effects of these contaminants in wildlife in the Great Lakes (International Joint Commission 1993), less effort has been directed toward inland lakes and streams around the Great Lakes region (Swackhamer and Hites 1988). However, a few studies have shown that mercury contamination in fish from regional inland lakes may be at levels detrimental to humans or wildlife Grieb et al 1990;Mason and Sullivan 1997). The Michigan Department of Public Health issued a statewide fish consumption advisory in December 1988 for all inland lakes based on levels of mercury contamination.…”

Influence of Fluctuating Water Levels on Mercury Concentrations in Adult Walleye

“…This may be due to the high methylation rates resulting from organic matter decomposition that followed water level increases in the 1990s. Further, low pH (<7.0) increases microbial methylation of mercury Grieb et al 1990;Hakanson 2003), but water pH was relatively high in our study lakes (mean = 8.9 ± 0.04 SE), and may explain why pH did not influence Hg contamination.…”

“…The discovery of elevated Hg concentrations in fishes was surprising because (1) there were no apparent pointsource inputs of Hg, and (2) the limnological conditions of most of these lakes (eutrophic, high pH) generally do not favor Hg methylation or bioaccumulation (Grieb et al 1990;Pickhardt et al 2002). Moreover, lakes that experienced large increases in surface area generally contained fast growing fish populations, a situation that usually lowers Hg concentration due to growth dilution (Rodgers and Qadri 1982;MacCrimmon et al 1983).…”