Mercury Analysis of Freshwater Game Fish Reveals Environmental Health Concerns for Central Mississippi and the Southeastern United States

Mercury pollution in aquatic systems across the United States is a major environmental health concern for both humans and wildlife. Mercury exposure causes neurological, cardiovascular, and kidney damage. Exposure can negatively impact brain development in children or during pregnancy. Early reports indicate that mercury contamination in fish species is problematic for the lakes of northern Mississippi. The level of mercury contamination in fish in central Mississippi lakes and their threat to public health are unknown. In this study, we assessed the mercury levels of major fish species from a central Mississippi lake, Calling Panther Lake, to determine their consumption hazards for both humans and piscivorous wildlife. Largemouth bass (Micropterus salmoides), black crappie (Pomoxis nigromaculatus), and channel catfish (Ictalurus punctatus) had mercury levels exceeding the 0.2 mg/kg WHO permissible limit, indicating mercury consumption risks for adults consuming an 8.0 oz serving size. All fish were within safe EPA limits for a 4.0 oz serving, except the black crappie. Health hazard assessments indicated mercury health risks for children. The meta-analysis of major freshwater game fish determined that mercury problems were consistent across the southeastern United States, creating consumption hazards for both piscivorous birds and piscivorous animals. All major freshwater game fish species had levels above the safe limits for wildlife consumption, suggesting mercury hazards for piscivorous wildlife in the southeast, with largemouth bass being a primary concern. Overall, our results found mercury concerns at Calling Panther Lake, Mississippi, for both humans and piscivorous wildlife, warranting future studies throughout central Mississippi to determine environmental health impacts across the region. Mercury levels in major freshwater game fish across the southeastern United States are a concern for both piscivorous birds and piscivorous animals, warranting future biomagnification studies throughout the southeastern United States.