Water quality is a key issue facing the restoration
of the Florida Everglades. For example, agriculturally derived phosphorus
entering the Everglades has caused eutrophication of 6 to 10 percent
of the ecosystem, resulting in changes in the native plant communities.
Phosphorus contamination remains an important issue facing Everglades
restoration, but recent work by the U.S. Geological Survey (USGS) has
pointed to other water-quality issues critical to the overall health
of the Everglades ecosystem.
Among the most important of these other water-quality issues in the Everglades is sulfate (SO42-) contamination. Sulfate contamination affects as much as one-third of the freshwater Everglades, and sulfate concentrations are 60 to 100 times historical levels in heavily affected areas. The effects of sulfate contamination on ecosystem health have not been fully studied, but links between sulfate contamination and high levels of methylmercury in the ecosystem have been documented. Also, sulfate contamination may be contributing to declines in native plants by altering chemical conditions in the sediments. Ongoing USGS research will further delineate these effects and explore possible options for mitigating sulfate contamination in this unique ecosystem.