Public concern for wildlife and human health problems due to mercury (Hg) toxicity has increased substantially since the mid-1980's. These concerns are manifested primarily by the issuance of fish consumption advisories in the majority of U.S. states, Canada, and several European countries because of high levels of mercury in game fish. Although the precise causes for this contamination problem are not completely understood, it appears that there are both source and ecosystem-specific factors that can result in elevated levels of mercury in game fish. Because mercury is known to adversely affect the human brain and nervous system, health concerns arise when elevated concentrations of mercury are detected in game fish from ecosystems where there is subsistence level consumption of fish. In extreme cases such as the Everglades, where mercury concentrations in fish consistently exceed the Florida advisory level of 1.5 parts per million, even occasional fish consumption is not recommended.

The USGS South Florida Ecosystem Program is part of an intergovernmental effort to restore and maintain the ecosystem of south Florida. One element of the restoration effort is the development of a scientific basis for resource management decisions. Mercury contamination in the Everglades has been identified by local, state, and national agencies as a topic of great concern, and in need of research to provide the information to base restoration plans. The South Florida Water Management District (SFWMD), Florida Department of Environmental Protection (FDEP), U.S. Environmental Protection Agency (USEPA), and the National Marine Fisheries Service need information on mercury cycling to predict the effects of proposed restoration plans on mercury exposure. The Everglades Forever Act of 1994 has mandated management decisions regarding what can be done to mitigate the toxic effects of mercury in the Everglades.

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