Ecotoxicology

, Volume 17, Issue 7, pp 632–641

Ecological risk of methylmercury in Everglades National Park, Florida, USA

  • D. G. Rumbold
  • T. R. Lange
  • D. M. Axelrad
  • T. D. Atkeson
Article

DOI: 10.1007/s10646-008-0234-9

Cite this article as:
Rumbold, D.G., Lange, T.R., Axelrad, D.M. et al. Ecotoxicology (2008) 17: 632. doi:10.1007/s10646-008-0234-9

Abstract

Dramatic declines in mercury levels have been reported in Everglades biota in recent years. Yet, methylmercury (MeHg) hot spots remain. This paper summarizes a risk assessment of MeHg exposure to three piscivorous wildlife species (bald eagle, Haliaeetus leucocephalus; wood stork, Mycteria americana; and great egret, Ardea albus) foraging at a MeHg hot spot in northern Everglades National Park (ENP). Available data consisted of literature-derived life history parameters and tissue concentrations measured in 60 largemouth bass (Micropterus salmoides), 60 sunfish (Lepomis spp.), and three composite samples of mosquitofish (Gambusia holbrooki) collected from 2003 to 2005. To assess risk, daily MeHg intake was estimated using Monte Carlo methods and compared to literature-derived effects thresholds. The results indicated the likelihood was very high, ranging from 98–100% probability, that these birds would experience exposures above the acceptable dose when foraging in northern ENP. Moreover, the likelihood that these birds would experience exposures above the lowest-observed-adverse-effect level (LOAEL) ranged from a 14% probability for the wood stork to 56% probability for the eagle. Data from this study, along with the results from several other surveys suggest that biota in ENP currently contain the highest MeHg levels in South Florida and that these levels are similar to or greater than other known MeHg hot spots in the United States. Given these findings, this paper also outlines a strategic plan to obtain additional measured and modeled information to support risk-based management decisions in ENP.

Keywords

MethylmercuryRiskBald eagleWood storkGreat egret

Copyright information

© Springer Science+Business Media, LLC 2008

Authors and Affiliations

  • D. G. Rumbold
    • 1
    • 2
  • T. R. Lange
    • 3
  • D. M. Axelrad
    • 4
  • T. D. Atkeson
    • 4
  1. 1.South Florida Water Management DistrictWest Palm BeachUSA
  2. 2.Department of Marine and Ecological SciencesFlorida Gulf Coast UniversityFt. MyersUSA
  3. 3.Fish and Wildlife Research InstituteEustisUSA
  4. 4.Florida Department of Environmental ProtectionTallahasseeUSA