Estuaries and Coasts

, Volume 34, Issue 3, pp 494–513 | Cite as

Source Identification of Florida Bay's Methylmercury Problem: Mainland Runoff Versus Atmospheric Deposition and In situ Production

  • Darren G. RumboldEmail author
  • David W. Evans
  • Sharon Niemczyk
  • Larry E. Fink
  • Krysten A. Laine
  • Nicole Howard
  • David P. Krabbenhoft
  • Mark Zucker


The first advisory to limit consumption of Florida Bay fish due to mercury was issued in 1995. Studies done by others in the late 1990s found elevated water column concentrations of both total Hg (THg) and methylmercury (MeHg) in creeks discharging from the Everglades, which had its own recognized mercury problem. To investigate the significance of allochthonous MeHg discharging from the upstream freshwater Everglades, we collected surface water and sediment along two transects from 2000 to 2002. Concentrations of THg and MeHg, ranging from 0.36 ng THg/L to 5.98 ng THg/L and from <0.02 ng MeHg/L to 1.79 ng MeHg/L, were elevated in the mangrove transition zone when compared both to upstream canals and the open waters of Florida Bay. Sediment concentrations ranged from 5.8 ng THg/g to 145.6 ng THg/g and from 0.05 ng MeHg/g to 5.4 ng MeHg/g, with MeHg as a percentage of THg occasionally elevated in the open bay. Methylation assays indicated that sediments from Florida Bay have the potential to methylate Hg. Assessment of mass loading suggests that canals delivering stormwater from the northern Everglades are not as large a source as direct atmospheric deposition and in situ methylation, especially within the mangrove transition zone.


Florida Bay Everglades Methylmercury Surface water Sediment 



The authors would like to thank Angela Drummond and Mark Kromer (SFWMD) for their help in field sampling. We thank Carl Mitchell and David Rudnick for their comments on an early draft of the manuscript and two anonymous reviewers for a later daft. We would like to acknowledge also the hard work of chemists at FDEP, FGS, and CEBAM, especially Lian Lang. We gratefully acknowledge the use of ENP facilities on Key Largo that were used in support of fieldwork. Finally, funding was provided through NOAA's Coastal Oceans Program and administered by the South Florida Ecosystem Restoration Prediction and Modeling program (SFERPM). Other funding was provided by the SFWMD and the NMFS's Southeast Fisheries Science Center.


  1. Ache, B.W., J.D. Boyle, and C.E. Morse. 2000. A survey of the occurrence of mercury in the fishery resources of the Gulf of Mexico. Prepared by Battelle for the USEPA Gulf of Mexico Program, Stennis Space Center, MS. MS. USA. Accessed 8 January 2009.
  2. Adams, D.H., and R.H. McMichael, Jr. 2001. Mercury levels in marine and estuarine fishes of Florida. Florida Fish and Wildlife Conservation Commission, FMRI Technical Report TR-6.Google Scholar
  3. Adams, D.H., and R.H. McMichael, Jr., G.E. Henderson. 2003. Mercury levels in marine and estuarine fishes of Florida 1989–2001. Florida Fish and Wildlife Conservation Commission, FMRI Technical Report TR-9. Accessed 10 January 2009.
  4. Armitage, A.R., T.A. Frankovich, and J.W. Fourqurean. 2006. Variable responses within epiphytic and benthic microalgal communities to nutrient enrichment. Hydrobiologia 569: 423–435.CrossRefGoogle Scholar
  5. Barkay, T., M. Gillman, and R.R. Turner. 1997. Effects of dissolved organic carbon and salinity on bioavailability of mercury. Applied Environmental Microbiology 63: 4267–4271.Google Scholar
  6. Benoit, J.M., C.C. Gilmour, R.P. Mason, G.S. Riedel, and G.F. Reidel. 1998. Behavior of mercury in the Patuxent River estuary. Biogeochemistry 40: 249–265.CrossRefGoogle Scholar
  7. Benoit, J.M., C.C. Gilmour, R.P. Mason, and A. Heyes. 1999. Sulfide controls on mercury speciation and bioavailability to methylating bacteria in sediment pore waters. Environmental Science and Technology 33: 951–957.CrossRefGoogle Scholar
  8. Bloom, N.S., G.A. Gill, S. Cappellino, C. Dobbs, L. McShea, C. Driscoll, R. Mason, and J. Rudd. 1999. Speciation and cycling of mercury in Lavaca Bay, Texas, sediments. Environmental Science and Technology 33: 7–3.CrossRefGoogle Scholar
  9. Cantillo, A.Y., G.G. Lauenstein, and T.P. O'Connor. 1997. Mollusc and sediment contaminant levels and trends in South Florida Coastal Waters. Marine Pollution Bulletin 34: 511–521.CrossRefGoogle Scholar
  10. Carlson Jr., P.R., L.A. Yarbro, and T.R. Barber. 1994. Relationship of sediment sulfide to mortality of Thalassia testudinum in Florida Bay. Bulletin of Marine Science 54: 733–746.Google Scholar
  11. Chambers, R.M., J.W. Fourqurean, S.A. Macko, and R. Hoppenot. 2001. Biogeochemical effects of iron availability on primary producers in a shallow marine carbonate environment. Limnology and Oceanography 46: 1278–1286.CrossRefGoogle Scholar
  12. Cohen, M.J., S. Lamsal, T.Z. Osborne, J.C.J. Bonzongo, S. Newman, and K.R. Reddy. 2009. Soil total mercury concentrations across the Greater Everglades. Soil Science Society of America, Journal 73: 675–685.CrossRefGoogle Scholar
  13. Conaway, C., S. Squire, R.P. Mason, and A.R. Flegal. 2003. Mercury speciation in the San Francisco Bay estuary. Marine Chemistry 80: 199–225.CrossRefGoogle Scholar
  14. Cornwell, J.C., W.M. Kemp, M.S. Owens, J. Davis, and E. Nagel. 2003. Internal Nutrient Cycling in Florida Bay: Denitrification, Nitrogen Fixation and the Role of Microalgae.(Published abstract). In Joint Conference on the Science and Restoration of the Greater Everglades and Florida Bay Ecosystem, "From Kissimmee to the Keys". April 13–18, 2003. Accessed 1 February 2009.
  15. Cosby, B.J., W.K. Nuttle, and J.W. Fourqurean. 2003. FATHOM: Model description and initial application to Florida Bay. Report to Everglades National Park, National Park Service. U.S. Dept. of Interior, Washington, D.C.Google Scholar
  16. Cossa, D., C. Gobeil, and P. Courau. 1988. Dissolved mercury behaviour in the St. Lawrence Estuary. Estuarine Coastal and Shelf Science 26: 227–230.CrossRefGoogle Scholar
  17. Evans, D.W., and P.J. Crumley. 2005. Mercury in Florida Bay Fish: spatial distribution of elevated concentrations and possible linkages to Everglades restoration. Bulletin of Marine Science 77: 321–345.Google Scholar
  18. Florida Department of Environmental Protection (FDEP). 2003. Integrating atmospheric mercury deposition with aquatic cycling in South Florida: an approach for conducting a total maximum daily load analysis for an atmospherically derived pollutant. Tallahassee: Florida Department of Environmental Protection.Google Scholar
  19. Florida Department of Health (FDOH). 2009. Your guide to eating fish caught in Florida. Tallahassee, FL. 2009 Fish Brochure.pdf. Accessed 3 March 2010.
  20. Fink, L., D.G. Rumbold, and P. Rawlik. 1999. Chapter 7. The Everglades mercury problem. In Everglades Interim Report. South Florida Water Management District. West Palm Beach, FL. Accessed 3 March 2010.
  21. Fitzgerald, W.F., and T.W. Clarkson. 1991. Mercury and monomethylmercury: present and future concerns. Environmental Health Perspective 96: 159–166.CrossRefGoogle Scholar
  22. Gagnon, C., E. Pelletier, A. Mucci, and W.F. Fitzgerald. 1996. Diagenetic behavior of methylmercury in organic rich coastal sediments. Limnology and Oceanography 41: 428–434.CrossRefGoogle Scholar
  23. Gilmour, C.C., and E.A. Henry. 1991. Mercury methylation in aquatic systems affected by acid deposition. Environmental Pollution 71: 131–169.CrossRefGoogle Scholar
  24. Gilmour, C.C., G.S. Riedel, M.C. Ederington, J.T. Bell, J.M. Benoit, G.A. Gill, and M.C. Stordal. 1998. Methylmercury concentrations and production rates across a trophic gradient in the northern Everglades. Biogeochemistry 40: 327–345.CrossRefGoogle Scholar
  25. Goodman, L.R., M.A. Lewis, J.M. Macauley, R. Smith Jr., and J.C. Morre. 1999. Preliminary survey of chemical contaminants in water, sediment, and aquatic biota at selected sites in northeastern Florida Bay and Canal C-111. Gulf of Mexico Science 17: 1–16.Google Scholar
  26. Guentzel, J.L., and Y. Tsukamoto. 2001. Processes influencing mercury speciation and bioconcentration in the North Inlet-Winyah Bay Estuary, South Carolina, USA. Marine Pollution Bulletin 42: 615–619.CrossRefGoogle Scholar
  27. Hall, B.D., H. Manolopoulos, J.P. Hurley, J.J. Schauer, V.L. St, D.K. Louis, J. Graydon, C.L. Babiarz, L.B. Cleckner, and G.J. Keeler. 2005. Methyl and total mercury in precipitation in the Great Lakes region. Atmospheric Environment 39: 7557–7569.CrossRefGoogle Scholar
  28. Hammerschmidt, C.R., and W.F. Fitzgerald. 2004. Geochemical controls on the production and distribution of methylmercury in near-shore marine sediments. Environmental Science and Technology 38: 1487–1495.CrossRefGoogle Scholar
  29. Hammerschmidt, C., W. Fitzgerald, C. Lamborg, P. Balcom, and P. Visscher. 2004. Biogeochemistry of methylmercury in sediments of Long Island Sound. Marine Chemistry 90: 31–52.CrossRefGoogle Scholar
  30. Heyes, A., R.P. Mason, E.-H. Kim, and E. Sunderland. 2006. Mercury methylation in estuaries: Insights from using measuring rates using stable mercury isotopes. Marine Chemistry 102: 134–147.CrossRefGoogle Scholar
  31. Hintelmann, H., and R.D. Evans. 1997. Application of stable isotopes in environmental tracer studies—measurement of monomethylmercury by isotope dilution ICP-MS and detection of species transformation. Fresenius’ Journal of Analytical Chemistry 358: 378–385.CrossRefGoogle Scholar
  32. Hittle, C.D., E. Patino, and M. Zucker. 2001. Freshwater Flow from Estuarine Creeks into Northeastern Florida Bay: USGS Water-Resources Investigation Report 01-4164. Accessed 3 March 2010.
  33. Horvat, M., S. Covelli, J. Faganeli, M. Logar, V. Mandic, R. Rajar, A. Sirca, and D. Zagar. 1999. Mercury in contaminated coastal environments. A case study: the Gulf of Trieste. Science of the Total Environment 237–238: 43–56.CrossRefGoogle Scholar
  34. Kang, W.J., J.H. Trefry, T.A. Nelson, and H.R. Wanless. 2000. Direct atmospheric inputs versus runoff fluxes of mercury to the lower Everglades and Florida Bay. Environmental Science and Technology 34: 4058–4063.CrossRefGoogle Scholar
  35. Kannan, K., R.G. Smith Jr., R.F. Lee, H.L. Windom, P.T. Heitmuller, J.M. Macauley, and J.K. Summers. 1998. Distribution of total mercury and methylmercury in water, sediment, and fish from South Florida Estuaries. Archives of Environmental Contamination and Toxicology 34: 109–118.CrossRefGoogle Scholar
  36. King, J.K., J.E. Kostka, M.E. Frischer, and F.M. Saunders. 2000. Sulfate-reducing bacteria methylate mercury as variable rates in pure culture and in marine sediments. Applied Environmental Microbiology 66: 2430–2437.CrossRefGoogle Scholar
  37. Lacerda, L.D., L.F.F. Silva, R.V. Marins, S. Mounier, H.H.M. Paraquetti, and J. Benaim. 2001. Dissolved mercury concentrations and reactivity in mangrove waters from Itacurussa Experimental Forest, Sepetiba Bay, S.E. Brazil. Wetlands Ecology and Management 9: 323–331.CrossRefGoogle Scholar
  38. Lambertsson, L., and M. Nilsson. 2006. Organic material: the primary control on mercury methylation and ambient methyl mercury concentration in estuarine sediments. Environmental Science and Technology 40: 1822–1829.CrossRefGoogle Scholar
  39. Langer, C.S., W.F. Fitzgerald, P.T. Visscher, and G.M. Vandal. 2001. Biogeochemcial cycling at Barn Island Salt Marsh, Stonington, CT, USA. Wetlands Ecology and Management 9: 295–310.CrossRefGoogle Scholar
  40. Le Roux, S.M., A. Turner, G.E. Millward, L. Ebdon, and P. Approiu. 2001. Partitioning of mercury onto suspended sediments in estuaries. Journal of Environmental Monitoring 3: 37–42.CrossRefGoogle Scholar
  41. Lee, T.N., E. Johns, D. Wilson, E. Williams, and N. Smith. 2002. Transport processes linking south Florida coastal ecosystems. In The everglades, Florida Bay, and coral reefs of the Florida Keys, an ecosystem source book, ed. J.W. Porter and K.G. Porter, 309–342. Boca Raton: CRC.Google Scholar
  42. Levesque, V.A. 2004. Water Flow and Nutrient Flux from Five Estuarine Rivers along the Southwest Coast of the Everglades National Park, Florida, 1997–2001. U.S. Geological Survey Scientific Investigations Report 2004-5142. Accessed 3 March 2010.
  43. Lores, E.M., J. Macauley, L.R. Goodman, R.G. Smith, and D.M. Wells. 1998. Factors affecting bioavailability of methyl mercury in Florida Bay (Abstract). In Natural Connections: Environmental integrity and human health: Abstract Book: SETAC 19th Annual Meeting, November 15 through 19, 1998, Charlotte, NC. Abstr. No. 468. p. 101. Pensacola. Society of Environmental Toxicology and Chemistry.Google Scholar
  44. Marvin-DiPasquale, M., J. Agee, R. Bouse, and B. Jaffe. 2003. Microbial cycling of mercury in contaminated pelagic and wetland sediments of San Pablo Bay, California. Environmental Geology 43: 260–267.Google Scholar
  45. Mason, R.P., and A.L. Lawrence. 1999. Concentration, distribution, and bioavailability of mercury and methylmercury in sediments of Baltimore Harbor and Chesapeake Bay, Maryland, USA. Environmental Toxicology and Chemistry 18: 2438–2447.Google Scholar
  46. Mason, R.P., N.M. Lawson, A.L. Lawrence, J.J. Leaner, J.G. Lee, and G.R. Sheu. 1999. Mercury in the Chesapeake Bay. Marine Chemistry 65: 77–96.CrossRefGoogle Scholar
  47. Mason, R.P., E.H. Kim, J. Cornwell, and D. Heyes. 2006. An examination of the factors influencing the flux of mercury, methylmercury and other constituents from estuarine sediment. Marine Chemistry 102: 96–110.CrossRefGoogle Scholar
  48. Moya, J., C. Itkin, S.G. Selevan, J.W. Rogers, and R.P. Clickner. 2008. Estimates of fish consumption rates for consumers of bought and self-caught fish in Connecticut, Florida, Minnesota, and North Dakota. Science of the Total Environment 403: 89–98.CrossRefGoogle Scholar
  49. Niu, X., and A. Tintle. 2003. Statistical Analysis and Summary of the HgRR3 Mercury Round Robin Data. Report prepared for Florida Department of Environmental Protection. Tallahassee, Fl. Accessed 3 March 2010.
  50. Nuttle, W. 2002. Report#1: Review and Evaluation of Hydrologic Modeling Tools for the Coastal Mangroves and Florida Bay. Project report for Everglades National Park, April 2002. Accessed 8 January 2009.
  51. Robblee, M.B., T.R. Barber, P.R. Carlson Jr., M.J. Durako, J.W. Fourqurean, L.K. Muehlstein, D. Porter, L.A. Yarbro, R.T. Zieman, and J.C. Zieman. 1991. Mass mortality of the tropical seagrass Thalassia testudinum in Florida Bay (USA). Marine Ecology Progress Series 71: 297–299.CrossRefGoogle Scholar
  52. Rumbold, D.G., and L.E. Fink. 2006. Extreme spatial variability and unprecedented methylmercury concentrations within a constructed wetland. Environmental Monitoring and Assessment 112: 115–135.CrossRefGoogle Scholar
  53. Rumbold, D., N. Niemeyer, F. Matson, S. Atkins, J. Jean-Jacques, K. Nicholas, C. Owens, K. Strayer, and B. Warner. 2007a. Appendix 3B-1: Annual permit compliance monitoring report for mercury in downstream receiving waters of the Everglades Protection Area. In 2007 South Florida Environmental Report, Vol. 1. South Florida Water Management District, West Palm Beach, FL. Accessed 3 March 2010.
  54. Rumbold, D., N. Niemeyer, F. Matson, S. Atkins, J. Jean-Jacques, K. Nicholas, C. Owens, K. Strayer, and B.Warner. 2007b. Appendix 5-5: Annual permit compliance monitoring report for mercury in Stormwater Treatment Areas. In 2007 South Florida Environmental Report, Vol. 1. South Florida Water Management District, West Palm Beach, FL. Accessed 3 March 2010.
  55. Schaffranek, R.W., H.L. Jenter, C.D. Langevin, and E.D. Swain. 2001. The tides and inflows in the mangroves of the Everglades project (Abstract). In Program & Abstracts: 2001 Florida Bay Science Conference, Key Largo, Florida, April 23–26, 2001. Accessed 3 March 2010.
  56. Scheidt, D.J., and P.I. Kalla. 2007. Everglades ecosystem assessment: water management, water quality, eutrophication, mercury contamination, soils and habitat. Monitoring for adaptive management: a R-EMAP status report. EPA 904-R-07-001. Atlanta, Georgia: United States Environmental Protection Agency.Google Scholar
  57. Stober, J., D. Scheidt, R. Jones, K. Thornton, R. Ambrose, and D. France. 1996. South Florida Ecosystem Assessment. Monitoring for Adaptive Management: Implications for Ecosystem Restoration. Interim Report. EPA-904-R-96-008. Athens, Georgia: United States Environmental Protection Agency.Google Scholar
  58. Stober, J., D. Scheidt, R. Jones, K. Thornton, R. Ambrose, and D. France. 1998. South Florida Ecosystem Assessment. Monitoring for Adaptive Management: Implications for Ecosystem Restoration. Final Technical Report—Phase I. United States Environmental Protection Agency EPA-904-R-96-008. Athens, Georgia.Google Scholar
  59. Strom, D.G., and G.A. Graves. 2001. A comparison of mercury in estuarine fish between Florida Bay and Indian River Lagoon, Florida, U.S.A. Estuaries 24: 597–609.CrossRefGoogle Scholar
  60. Sunderland, E.M. 2007. Mercury exposure from domestic and imported estuarine and marine fish in the U.S. seafood market. Environmental Health Perspectives 115: 235–242.CrossRefGoogle Scholar
  61. Sunderland, E.M., F.A.P.C. Gobas, A. Heyes, B.A. Branfireun, A.K. Bayer, R.E. Cranston, and M.B. Parsons. 2004. Speciation and bioavailability of mercury in well-mixed estuarine sediments. Marine Chemistry 90: 91–105.CrossRefGoogle Scholar
  62. Sunderland, E.M., F.A.P.C. Gobas, A. Heyes, and B.A. Branfireun. 2006. Environmental controls on the speciation and distribution of mercury in coastal sediments. Marine Chemistry 102: 111–123.CrossRefGoogle Scholar
  63. U.S. Environmental Protection Agency (U.S.EPA). 2007. National Listing of Fish Advisories. Accessed 8 January 2009.

Copyright information

© Coastal and Estuarine Research Federation 2010

Authors and Affiliations

  • Darren G. Rumbold
    • 1
    • 2
    Email author
  • David W. Evans
    • 3
  • Sharon Niemczyk
    • 1
    • 4
  • Larry E. Fink
    • 1
  • Krysten A. Laine
    • 5
  • Nicole Howard
    • 1
  • David P. Krabbenhoft
    • 6
  • Mark Zucker
    • 7
  1. 1.South Florida Water Management DistrictWest Palm BeachUSA
  2. 2.Florida Gulf Coast UniversityFt. MyersUSA
  3. 3.National Oceanic and Atmospheric AdministrationBeaufortUSA
  4. 4.The Abaco Group, LLCBoynton BeachUSA
  5. 5.East Bay Municipal Utility DistrictOaklandUSA
  6. 6.U.S. Geological SurveyMiddletonUSA
  7. 7.U.S. Geological SurveyFt. LauderdaleUSA

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