title: Regional, temporal, and species patterns of mercury in Alaskan seabird eggs: mercury sources and cycling or food web effects?
abstract: Mercury concentration ([Hg]), δ(15)N, and δ(13)C values were measured in eggs from common murres (Uria aalge), thick-billed murres (U. lomvia), glaucous gulls (Larus hyperboreus), and glaucous-winged gulls (L. glaucescens) collected in Alaska from 1999 to 2005. [Hg] was normalized to a common trophic level using egg δ(15)N values and published Hg trophic magnification factors. Egg [Hg] was higher in murres from Gulf of Alaska, Cook Inlet, and Norton Sound regions compared to Bering Sea and Bering Strait regions, independent of trophic level. We believe the Yukon River outflow and terrestrial Hg sources on the southern Seward Peninsula are responsible for the elevated [Hg] in Norton Sound eggs. Normalizing for trophic level generally diminished or eliminated differences in [Hg] among taxa, but temporal variability was unrelated to trophic level. Normalizing murre egg [Hg] by trophic level improves the confidence in regional comparisons of Hg sources and biogeochemical cycling in Alaska.
authors.affiliation: National Institute of Standards and Technology, Analytical Chemistry Division, Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC 29412, USA. russell.day@nist.gov
authors.forename: Rusty D
authors.initials: RD
authors.lastname: Day
authors.forename: David G
authors.initials: DG
authors.lastname: Roseneau
authors.forename: Stacy S
authors.initials: SS
authors.lastname: Vander Pol
authors.forename: Keith A
authors.initials: KA
authors.lastname: Hobson
authors.forename: Olivier F X
authors.initials: OF
authors.lastname: Donard
authors.forename: Rebecca S
authors.initials: RS
authors.lastname: Pugh
authors.forename: Amanda J
authors.initials: AJ
authors.lastname: Moors
authors.forename: Paul R
authors.initials: PR
authors.lastname: Becker
mesh_terms: D000413:Alaska; D000818:Animals; D001717:Birds; D055669:Ecological and Environmental Phenomena; D004784:Environmental Monitoring; D004785:Environmental Pollutants / Q000032:analysis*; D004787:Environmental Pollution / Q000706:statistics & numerical data; D020387:Food Chain; D008628:Mercury / Q000032:analysis*; D010063:Ovum / Q000737:chemistry*
chemical_list: D004785:Environmental Pollutants; D008628:Mercury