title: Rapidly increasing methyl mercury in endangered ivory gull (Pagophila eburnea) feathers over a 130 year record.
abstract: Mercury (Hg) is increasing in marine food webs, especially at high latitudes. The bioaccumulation and biomagnification of methyl mercury (MeHg) has serious effects on wildlife, and is most evident in apex predators. The MeHg body burden in birds is the balance of ingestion and excretion, and MeHg in feathers is an effective indicator of overall MeHg burden. Ivory gulls (Pagophila eburnea), which consume ice-associated prey and scavenge marine mammal carcasses, have the highest egg Hg concentrations of any Arctic bird, and the species has declined by more than 80% since the 1980s in Canada. We used feathers from museum specimens from the Canadian Arctic and western Greenland to assess whether exposure to MeHg by ivory gulls increased from 1877 to 2007. Based on constant feather stable-isotope (δ(13)C, δ(15)N) values, there was no significant change in ivory gulls' diet over this period, but feather MeHg concentrations increased 45× (from 0.09 to 4.11 µg g(-1) in adults). This dramatic change in the absence of a dietary shift is clear evidence of the impact of anthropogenic Hg on this high-latitude threatened species. Bioavailable Hg is expected to increase in the Arctic, raising concern for continued population declines in high-latitude species that are far from sources of environmental contaminants.
authors: Department of Biology, University of Saskatchewan, 112 Science Place, Saskatoon, Saskatchewan, Canada S7N 5E2 Environment Canada, 11 Innovation Boulevard, Saskatoon, Saskatchewan, Canada S7N 3H5 alex.bond@rspb.org.uk.
authors: Alexander L
authors: AL
authors: Bond
authors: Environment Canada, 11 Innovation Boulevard, Saskatoon, Saskatchewan, Canada S7N 3H5.
authors: Keith A
authors: KA
authors: Hobson
authors: Department of Biology and Centre for Environment and Sustainability, Western University, Biological and Geological Sciences Building, London, Ontario, Canada N6A 5B7.
authors: Brian A
authors: BA
authors: Branfireun
mesh_terms: D000818:Animals; D001110:Arctic Regions; D002170:Canada; D002247:Carbon Isotopes / Q000032:analysis; D046091:Charadriiformes / Q000378:metabolism*; D004032:Diet; D056727:Endangered Species; D004781:Environmental Exposure; D004784:Environmental Monitoring; D005241:Feathers / Q000737:chemistry*; D005260:Female; D006116:Greenland; D008297:Male; D008767:Methylmercury Compounds / Q000378:metabolism*; D009587:Nitrogen Isotopes / Q000032:analysis; D012621:Seasons; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D002247:Carbon Isotopes; D008767:Methylmercury Compounds; D009587:Nitrogen Isotopes; D014874:Water Pollutants, Chemical
keywords: Arctic; mercury; stable isotopes; threatened species; δ13C; δ15N