Show simple item record

dc.contributor.authorWalters, David M.
dc.contributor.authorRosi-Marshall, Emma
dc.contributor.authorKennedy, Theodore A.
dc.contributor.authorCross, Wyatt F.
dc.contributor.authorBaxter, Colden V.
dc.identifier.citationWalters, David M., Emma Rosi-Marshall, Theodore A. Kennedy, Wyatt F. Cross, and Colden V. Baxter. "Mercury & selenium accumulation in the Colorado River food web, Grand Canyon, USA." Environmental Toxicology & Chemistry 34, no. 10 (October 2015): 2385-2394. DOI: 10.1002/etc.3077.en_US
dc.description.abstractMercury (Hg) and selenium (Se) biomagnify in aquatic food webs and are toxic to fish and wildlife. The authors measured Hg and Se in organic matter, invertebrates, and fishes in the Colorado River food web at sites spanning 387 river km downstream of Glen Canyon Dam (AZ, USA). Concentrations were relatively high among sites compared with other large rivers (mean wet wt for 6 fishes was 0.17–1.59 μg g–1 Hg and 1.35–2.65 μg g–1 Se), but consistent longitudinal patterns in Hg or Se concentrations relative to the dam were lacking. Mercury increased (slope = 0.147) with δ15N, a metric of trophic position, indicating biomagnification similar to that observed in other freshwater systems. Organisms regularly exceeded exposure risk thresholds for wildlife and humans (6–100% and 56–100% of samples for Hg and Se, respectfully, among risk thresholds). In the Colorado River, Grand Canyon, Hg and Se concentrations pose exposure risks for fish, wildlife, and humans, and the findings of the present study add to a growing body of evidence showing that remote ecosystems are vulnerable to long‐range transport and subsequent bioaccumulation of contaminants. Management of exposure risks in Grand Canyon will remain a challenge, as sources and transport mechanisms of Hg and Se extend far beyond park boundaries.en_US
dc.description.sponsorshipUS Geological Survey Grand Canyon Monitoring & Research Center; the US Environmental Protection Agency Office of Research & Developmenten_US
dc.titleMercury and selenium accumulation in the Colorado River food web, Grand Canyon, USAen_US
mus.citation.journaltitleEnvironmental Toxicology & Chemistryen_US
mus.identifier.categoryLife Sciences & Earth Sciencesen_US
mus.relation.collegeCollege of Letters & Scienceen_US
mus.relation.universityMontana State University - Bozemanen_US

Files in this item


This item appears in the following Collection(s)

Show simple item record

MSU uses DSpace software, copyright © 2002-2017  Duraspace. For library collections that are not accessible, we are committed to providing reasonable accommodations and timely access to users with disabilities. For assistance, please submit an accessibility request for library material.