title: Influence of relative trophic position and carbon source on selenium bioaccumulation in turtles from a coal fly-ash spill site.
abstract: Selenium (Se) is a bioaccumulative constituent of coal fly-ash that can disrupt reproduction of oviparous wildlife. In food webs, the greatest enrichment of Se occurs at the lowest trophic levels, making it readily bioavailable to higher consumers. However, subsequent enrichment at higher trophic levels is less pronounced, leading to mixed tendencies for Se to biomagnify. We used stable isotopes ((1)(5)N and (13)C) in claws to infer relative trophic positions and relative carbon sources, respectively, of seven turtle species near the site of a recently-remediated coal fly-ash spill. We then tested whether Se concentrations differed with relative trophic position or relative carbon source. We did not observe a strong relationship between δ(15)N and Se concentration. Instead, selenium concentrations decreased with increasing δ(13)C among species. Therefore, in an assemblage of closely-related aquatic vertebrates, relative carbon source was a better predictor of Se bioaccumulation than was relative trophic position.
authors.affiliation: Department of Fish and Wildlife Conservation, Virginia Tech, 106 Cheatham Hall, Blacksburg, VA 24061, USA. Electronic address: james.vandyke@sydney.edu.au.
authors.forename: James U
authors.initials: JU
authors.lastname: Van Dyke
authors.forename: William A
authors.initials: WA
authors.lastname: Hopkins
authors.forename: Brian P
authors.initials: BP
authors.lastname: Jackson
mesh_terms: D000818:Animals; D060729:Coal Ash; D004784:Environmental Monitoring; D005260:Female; D020387:Food Chain; D008297:Male; D012643:Selenium / Q000032:analysis / Q000378:metabolism*; D014426:Turtles / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000378:metabolism*
chemical_list: D060729:Coal Ash; D014874:Water Pollutants, Chemical; D012643:Selenium
keywords: Biomagnification; Nondestructive sampling; Reptile; Stable isotopes; Trophic web