title: From tails to toes: developing nonlethal tissue indicators of mercury exposure in five amphibian species.
abstract: Exposure to environmental contaminants has been implicated as a factor in global amphibian decline. Mercury (Hg) is a particularly widespread contaminant that biomagnifies in amphibians and can cause a suite of deleterious effects. However, monitoring contaminant exposure in amphibian tissues may conflict with conservation goals if lethal take is required. Thus, there is a need to develop non-lethal tissue sampling techniques to quantify contaminant exposure in amphibians. Some minimally invasive sampling techniques, such as toe-clipping, are common in population-genetic research, but it is unclear if these methods can adequately characterize contaminant exposure. We examined the relationships between mercury (Hg) concentrations in non-lethally sampled tissues and paired whole-bodies in five amphibian species. Specifically, we examined the utility of three different tail-clip sections from four salamander species and toe-clips from one anuran species. Both tail and toe-clips accurately predicted whole-body THg concentrations, but the relationships differed among species and the specific tail-clip section or toe that was used. Tail-clips comprised of the distal 0-2 cm segment performed the best across all salamander species, explaining between 82 and 92% of the variation in paired whole-body THg concentrations. Toe-clips were less effective predictors of frog THg concentrations, but THg concentrations in outer rear toes accounted for up to 79% of the variability in frog whole-body THg concentrations. These findings suggest non-lethal sampling of tails and toes has potential applications for monitoring contaminant exposure and risk in amphibians, but care must be taken to ensure consistent collection and interpretation of samples.
authors.affiliation: Fisheries and Wildlife Department, Oregon State University, 104 Nash Hall, 2820 SE Campus Way, Corvallis, OR, 97331, USA.|Olympic National Park, 600 East Park Ave, Port Angeles, WA, 98362, USA.
authors.forename: Adam Z
authors.initials: AZ
authors.lastname: Pfleeger
authors.affiliation: U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, 3200 SW Jefferson Way, Corvallis, OR, 97331, USA. ceagles-smith@usgs.gov.
authors.forename: Collin A
authors.initials: CA
authors.lastname: Eagles-Smith
authors.affiliation: U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, 3200 SW Jefferson Way, Corvallis, OR, 97331, USA.
authors.forename: Brandon M
authors.initials: BM
authors.lastname: Kowalski
authors.affiliation: U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, 3200 SW Jefferson Way, Corvallis, OR, 97331, USA.
authors.forename: Garth
authors.initials: G
authors.lastname: Herring
authors.affiliation: U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, 3200 SW Jefferson Way, Corvallis, OR, 97331, USA.
authors.forename: James J
authors.initials: JJ
authors.lastname: Willacker
authors.affiliation: Fisheries and Wildlife Department, Oregon State University, 104 Nash Hall, 2820 SE Campus Way, Corvallis, OR, 97331, USA.
authors.forename: Allyson K
authors.initials: AK
authors.lastname: Jackson
authors.affiliation: U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, 3200 SW Jefferson Way, Corvallis, OR, 97331, USA.
authors.forename: John R
authors.initials: JR
authors.lastname: Pierce
mesh_terms: D000663:Amphibians / Q000502:physiology*; D000818:Animals; D004784:Environmental Monitoring / Q000379:methods* / Q000592:standards; D008628:Mercury / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D014874:Water Pollutants, Chemical; D008628:Mercury
keywords: Amphibian; Mercury; Non-lethal; Tail-clip; Toe-clip
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