HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Free Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (12) Citing Articles via Google Scholar Google Scholar Articles by Bates, A. L. Articles by Spiker, E. C. Search for Related Content PubMed PubMed Citation Articles by Bates, A. L. Articles by Spiker, E. C. Agricola Articles by Bates, A. L. Articles by Spiker, E. C. Related Collections Spatial Distribution Surface Water Quality Water Quality

TECHNICAL REPORT
Surface Water Quality

Tracing Sources of Sulfur in the Florida Everglades

United States Geological Survey, 956 National Center, Reston, VA 20192

* Corresponding author (abates{at}usgs.gov)

Received for publication August 12, 2000. We examined concentrations and sulfur isotopic ratios (³⁴S/³²S, expressed as ³⁴S in parts per thousand [] units) of sulfate in surface water, ground water, and rain water from sites throughout the northern Everglades to establish the sources of sulfur to the ecosystem. The geochemistry of sulfur is of particular interest in the Everglades because of its link, through processes mediated by sulfate-reducing bacteria, to the production of toxic methylmercury in this wetland ecosystem. Methylmercury, a neurotoxin that is bioaccumulated, has been found in high concentrations in freshwater fish from the Everglades, and poses a potential threat to fish-eating wildlife and to human health through fish consumption. Results show that surface water in large portions of the Everglades is heavily contaminated with sulfate, with the highest concentrations observed in canals and marsh areas receiving canal discharge. Spatial patterns in the range of concentrations and ³⁴S values of sulfate in surface water indicate that the major source of sulfate in sulfur-contaminated marshes is water from canals draining the Everglades Agricultural Area. Shallow ground water underlying the Everglades and rain water samples had much lower sulfate concentrations and ³⁴S values distinct from those found in surface water. The ³⁴S results implicate agricultural fertilizer as a major contributor to the sulfate contaminating the Everglades, but ground water under the Everglades Agricultural Area (EAA) may also be a contributing source. The contamination of the northern Everglades with sulfate from canal discharge may be a key factor in controlling the distribution and extent of methylmercury production in the Everglades.

Abbreviations: EAA, Everglades Agricultural Area • ENR, Everglades Nutrient Removal Area • MeHg, methylmercury • WCA, Water Conservation Area

This article has been cited by other articles:

				A. N. Hristov, W. Hazen, and J. W. Ellsworth Efficiency of Use of Imported Magnesium, Sulfur, Copper, and Zinc on Idaho Dairy Farms J Dairy Sci, June 1, 2007; 90(6): 3034 - 3043. [Abstract] [Full Text] [PDF]

				M. Chen, S. H. Daroub, T. A. Lang, and O. A. Diaz Specific conductance and ionic characteristics of farm canals in the everglades agricultural area. J. Environ. Qual., January 1, 2006; 35(1): 141 - 150. [Abstract] [Full Text] [PDF]

				H. Castro, S. Newman, K. R. Reddy, and A. Ogram Distribution and Stability of Sulfate-Reducing Prokaryotic and Hydrogenotrophic Methanogenic Assemblages in Nutrient-Impacted Regions of the Florida Everglades Appl. Envir. Microbiol., May 1, 2005; 71(5): 2695 - 2704. [Abstract] [Full Text] [PDF]

				H. Castro, K. R. Reddy, and A. Ogram Composition and Function of Sulfate-Reducing Prokaryotes in Eutrophic and Pristine Areas of the Florida Everglades Appl. Envir. Microbiol., December 1, 2002; 68(12): 6129 - 6137. [Abstract] [Full Text] [PDF]