title: Mercury bioaccumulation in an estuarine predator: Biotic factors, abiotic factors, and assessments of fish health.
abstract: Estuarine wetlands are major contributors to mercury (Hg) transformation into its more toxic form, methylmercury (MeHg). Although these complex habitats are important, estuarine Hg bioaccumulation is not well understood. The longnose gar Lepisosteus osseus (L. 1758), an estuarine predator in the eastern United States, was selected to examine Hg processes due to its abundance, estuarine residence, and top predator status. This study examined variability in Hg concentrations within longnose gar muscle tissue spatially and temporally, the influence of biological factors, potential maternal transfer, and potential negative health effects on these fish. Smaller, immature fish had the highest Hg concentrations and were predominantly located in low salinity waters. Sex and diet were also important factors and Hg levels peaked in the spring. Although maternal transfer occurred in small amounts, the potential negative health effects to young gar remain unknown. Fish health as measured by fecundity and growth rate appeared to be relatively unaffected by Hg at concentrations in the present study (less than 1.3 ppm wet weight). The analysis of biotic and abiotic factors relative to tissue Hg concentrations in a single estuarine fish species provided valuable insight in Hg bioaccumulation, biomagnification, and elimination. Insights such as these can improve public health policy and environmental management decisions related to Hg pollution.
authors.affiliation: Grice Marine Laboratory, College of Charleston, 205 Fort Johnson Road, Charleston, SC 29412, USA. Electronic address: Meredith.smylie@yale.edu.
authors.forename: Meredith S
authors.initials: MS
authors.lastname: Smylie
authors.affiliation: Marine Resources Division, South Carolina Department of Natural Resources, 217 Fort Johnson Road, Charleston, SC 29422, USA.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: McDonough
authors.affiliation: National Ocean Service, NOAA, Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC 29412, USA.
authors.forename: Lou Ann
authors.initials: LA
authors.lastname: Reed
authors.affiliation: Department of Biology and Geology, University of South Carolina Aiken, 471 University Parkway, Aiken, SC 29801, USA.
authors.forename: Virginia R
authors.initials: VR
authors.lastname: Shervette
mesh_terms: D000818:Animals; D017753:Ecosystem; D004784:Environmental Monitoring / Q000379:methods*; D005260:Female; D005399:Fishes; D008297:Male; D008628:Mercury / Q000032:analysis*; D008767:Methylmercury Compounds / Q000032:analysis*; D012621:Seasons; D014874:Water Pollutants, Chemical / Q000032:analysis*; D053833:Wetlands
chemical_list: D008767:Methylmercury Compounds; D014874:Water Pollutants, Chemical; D008628:Mercury
keywords: Lepisosteus osseus; Longnose gar; Methylmercury; Trophic ecology