title: Mercury offloaded in Northern elephant seal hair affects coastal seawater surrounding rookery.
abstract: Methylmercury (MeHg) is a potent neurotoxin that is biomagnified approximately 1-10 million-fold in aquatic carnivores such as the Northern elephant seal (Mirounga angustirostris), whose excreta and molted pelage, in turn, constitute a source of environmental MeHg contamination at the base of marine food chains. The potential for this top-down contamination is greatest in coastal areas with productive marine ecosystems that provide ideal habitats for large marine mammal colonies that can number in the thousands. This recycling of MeHg was evidenced by comparing total mercury (HgT) and MeHg concentrations in seawater, and HgT in molted pelage of M. angustirostris, at the Año Nuevo State Reserve pinniped rookery with concentrations at neighboring coastal sites in Central California. Seawater MeHg concentrations around the rookery (average = 2.5 pM) were markedly higher than those at the comparison coastal sites (average = 0.30 pM), and were as high as 9.5 pM during the M. angustirostris molting season. As a consequence, excreta and molts from this marine mammal colony, and presumably other marine predator populations, constitute a major source of MeHg at the base of the local marine food chain.
authors.affiliation: Department of Ecology and Evolutionary Biology, WIGS Laboratory, University of California, Santa Cruz, CA 95064; jennboon@rohan.sdsu.edu.
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Cossaboon
authors.affiliation: Department of Earth and Planetary Sciences, WIGS Laboratory, University of California, Santa Cruz, CA 95064;
authors.forename: Priya M
authors.identifier: http://orcid.org/0000-0002-5965-0230
authors.initials: PM
authors.lastname: Ganguli
authors.affiliation: Department of Microbiology and Environmental Toxicology, WIGS Laboratory, University of California, Santa Cruz, CA 95064.
authors.forename: A Russell
authors.initials: AR
authors.lastname: Flegal
mesh_terms: D000818:Animals; D001682:Biological Availability; D002140:California; D054750:Ecotoxicology; D004785:Environmental Pollutants / Q000032:analysis* / Q000633:toxicity; D005243:Feces / Q000737:chemistry; D006197:Hair / Q000737:chemistry*; D008628:Mercury / Q000032:analysis* / Q000633:toxicity; D008767:Methylmercury Compounds / Q000032:analysis; D046048:Seals, Earless / Q000378:metabolism*; D012623:Seawater / Q000737:chemistry*; D013050:Spectrometry, Fluorescence
chemical_list: D004785:Environmental Pollutants; D008767:Methylmercury Compounds; D008628:Mercury
keywords: biogeochemistry; biomagnification; environmental toxicology; marine mammals; mercury