Decadal trends of mercury cycling and bioaccumulation within Everglades National Park

Despite declines in atmospheric mercury (Hg) concentrations elsewhere in the U.S., Everglades National Park (ENP) showed no reduction in Hg deposition or related contaminants like dissolved organic carbon and sulfate from 2008 to 2018. A multimedia study across 76 sites revealed strong correlations between methylmercury (MeHg) levels in water and fish, particularly in the Shark River Slough (SRS) and coastal regions, where geochemical conditions favor bioaccumulation. The findings underscore that improved water quality and flow—key restoration targets—could mitigate MeHg exposure. The study highlights the complex interplay between hydrology, climate, and Hg cycling, offering critical insights for Everglades conservation efforts.

Janssen, S. E., Tate, M. T., Poulin, B. A., Krabbenhoft, D. P., DeWild, J. F., Ogorek, J. M., Varonka, M. S., Orem, W. H., & Kline, J. L. (2022). Decadal trends of mercury cycling and bioaccumulation within Everglades National Park. Science of the Total Environment, 838, 156031. https://doi.org/10.1016/j.scitotenv.2022.156031