This book integrates 30 years of mercury research in the Florida Everglades to inform scientists and policy makers. The Everglades is an iconic ecosystem by virtue of its expanse; diversity of biota; and multiple international designations. Despite this, the Everglades has been subjected to multiple threats including: habitat loss, hydrologic alterations, invasive species and altered water quality. Less well recognized as a threat to Everglades human use and wildlife populations is the toxic metal, mercury. The first half of Volume II focuses on biogeochemistry and factors unique to the Everglades that make it extraordinarily susceptible to mercury methylation following its deposition: warm subtropical climate, shallow depth, high levels of dissolved organic matter, sulfate contamination, nutrient enrichment and sediment redox conditions (for review of atmospheric mercury deposition significance, see Vol. I). The second half of Volume II answers the “so what” question – why biomagnification of the methylmercury produced in the Everglades is a threat to the health of top predators including humans. The results of the synthesis presented in Volume II suggest that the mercury problem in the Florida Everglades is one of the worst in the world due to its areal extent and the degree of risk to ecological receptors and humans.

This book is the final installation in a three-volume series synthesizing 30 years of mercury research in the Florida Everglades. The first part of this book evaluates the occurrence of trends in both biota mercury concentrations and atmospheric mercury deposition. Through both empirical and deterministic analyses, the likely drivers of biota trends are identified. These analyses help lay the predicate for devising an overall strategy to mitigate and manage the Everglades mercury problem. The book concludes with a model analysis of the likely benefits and uncertainty attendant with implementing the leading candidate strategy for best reducing the Everglades mercury problem.

This book integrates 30 years of mercury research on the Florida Everglades to inform scientists and policy makers. The Everglades is an iconic ecosystem by virtue of its expanse; diversity of biota; and multiple international designations. Despite this, the Everglades has been subjected to multiple threats including: habitat loss, hydrologic alterations, invasive species; and altered water quality. Less well recognized as a threat to Everglades human use and wildlife populations is the toxic metal, mercury. This Volume focuses on sources of mercury to the Everglades from the late-1980’s when there was bewilderment as to why there were very high levels of mercury in the Everglades food web. Soon came the finding that mercury loadings from atmospheric deposition accounted for over 95% of total input to the Everglades which resulted in Florida conducting the most comprehensive mercury monitoring and modeling study performed to date. Topics discussed in this Volume include: (1) Why atmospheric deposition fluxes of mercury to the Everglades are amongst the highest in the U.S; (2) That these are overwhelmingly from sources outside of the U.S; (3) That mitigation strategies for resolving the elevated food web mercury problem in the Everglades that rely solely on reducing atmospheric mercury inputs will not be effective for many decades; (4) That consideration of other strategies, in particular controlling factors related to Everglades mercury biogeochemical cycling seem warranted.