Mercury (Hg) is a toxic metal that is found in aquatic food webs and is hazardous to humans. An emerging conceptual model predicts that areas of the landscape that have the potential to contain food webs with elevated concentrations of Hg are those that receive high amounts of Hg and sulfate deposition and have high coverage of forests and wetlands and low coverage of agriculture. The objective of this study was to test the conceptual model using concentrations of Hg in largemouth bass (Micropterus salmoides) from 870 water bodies located in Arkansas, Louisiana, Oklahoma and Texas.
Results/Conclusions
The highest level of Hg contamination in fish was in the South Central Plains, an ecoregion that covers 152,000 km2 and includes parts of eastern Texas and Oklahoma and approximately half the states of Arkansas and Louisiana. The South Central Plains receives high levels of Hg and sulfate deposition and contains extensive forest and wetland habitat but little agriculture.