(Supplementary Table 1) Mercury isotope values for common and thick-billed murre (Uria aalge, Uria lomvia) eggs from Alaska
Cobertura |
MEDIAN LATITUDE: 59.826333 * MEDIAN LONGITUDE: -160.271667 * SOUTH-BOUND LATITUDE: 53.930000 * WEST-BOUND LONGITUDE: -170.250000 * NORTH-BOUND LATITUDE: 68.870000 * EAST-BOUND LONGITUDE: -135.700000 * DATE/TIME START: 1999-07-07T00:00:00 * DATE/TIME END: 2002-07-07T00:00:00 |
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Data(s) |
21/08/2011
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Resumo |
Atmospheric deposition of mercury to remote areas has increased threefold since pre-industrial times. Mercury deposition is particularly pronounced in the Arctic. Following deposition to surface oceans and sea ice, mercury can be converted into methylmercury, a biologically accessible form of the toxin, which biomagnifies along the marine food chain. Mass-independent fractionation of mercury isotopes accompanies the photochemical breakdown of methylmercury to less bioavailable forms in surface waters. Here we examine the isotopic composition of mercury in seabird eggs collected from colonies in the North Pacific Ocean, the Bering Sea and the western Arctic Ocean, to determine geographical variations in methylmercury breakdown at northern latitudes. We find evidence for mass-independent fractionation of mercury isotopes. The degree of mass-independent fractionation declines with latitude. Foraging behaviour and geographic variations in mercury sources and solar radiation fluxes were unable to explain the latitudinal gradient. However, mass-independent fractionation was negatively correlated with sea-ice cover. We conclude that sea-ice cover impedes the photochemical breakdown of methylmercury in surface waters, and suggest that further loss of Arctic sea ice this century will accelerate sunlight-induced breakdown of methylmercury in northern surface waters. |
Formato |
text/tab-separated-values, 473 data points |
Identificador |
https://doi.pangaea.de/10.1594/PANGAEA.818266 doi:10.1594/PANGAEA.818266 |
Idioma(s) |
en |
Publicador |
PANGAEA |
Direitos |
CC-BY: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted |
Fonte |
Supplement to: Point, David; Sonke, Jeroen E; Day, RD; Roseneau, DG; Hobson, Keith A; Vander Pol, SS; Moors, AJ; Pugh, RS; Donard, Olivier FX; Becker, PR (2011): Methylmercury photodegradation influenced by sea-ice cover in Arctic marine ecosystems. Nature Geoscience, 4(3), 188-194, doi:10.1038/ngeo1049 |
Palavras-Chave | #Area/locality; Bering Sea; Biological sample; BIOS; Bogoslof_Is; CapeLisburne; Chukchi Sea; DATE/TIME; delta 199Hg; Delta 199Hg; delta 200Hg; delta 201Hg; Delta 201Hg; delta 202Hg; E-Amatuli_Is; Event label; Gulf of Alaska; International Polar Year (2007-2008); IPY; Latitude of event; Longitude of event; Sample ID; Sample type; Species; Species, common name; StGeorge_Is; StLawrence_Is; StLazaria_Is |
Tipo |
Dataset |