Why Do Organochlorine Differences between Arctic Regions Vary among Trophic Levels?
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- 作者：Katrine Borgå ; Geir Wing Gabrielsen ; Janneche Utne Skaare ; Lars Kleivane ; Ross J. Norstrom ; and Aaron T. Fisk
- 刊名：Environmental Science & Technology
- 出版年：2005
- 出版时间：June 15, 2005
- 年：2005
- 卷：39
- 期：12
- 页码：4343 - 4352
- 全文大小：256K
- 年卷期：v.39,no.12(June 15, 2005)
- ISSN：1520-5851
文摘
Statistical analysis of organochlorine contaminants (OCs)in marine mammals has shown that, for most OCs, theEuropean Arctic is more contaminated than the Canadianand U.S. Arctic. Recently, comparison of OC concentrationranges in seabirds, arctic cod (Boregadus saida), andzooplankton, found no difference between these regions.To address these inconsistencies, marine food web OC datafrom the European (central Barents Sea (CBS)) andCanadian Arctic (Northwater Polynya (NOW)) weresimultaneously statistically analyzed. In general, concentrations of OCs were greater in seabirds and ringed seals(Phoca hispida) from the CBS as compared to the NOW;consistent with circumpolar trends observed in marinemammals. In contrast, levels of OCs were generally similarin zooplankton and arctic cod between the CBS andNOW. The main exception is HCH which had greater levelsin the NOW across all trophic levels because of thegreater proximity to sources in eastern Asia. The lack ofdifferences in OC concentrations in zooplankton and Arcticcod from the European and Canadian Arctic suggestthat regional differences in OC contamination in the Arctichave evened out. Reduced regional differences were notobserved in marine mammals or seabirds because they arelong-lived and also acquire contaminants from maternaltransfer and hence reflect levels from the past when theEuropean Arctic was more contaminated than the CanadianArctic. In addition, seabirds may reflect exposure fromother areas. This study highlights the potential problem ofcomparing spatial trends by using means and confidenceintervals as compared to simultaneous statistical analysis ofraw data. Differences in the spatial trends of OCs betweentrophic levels in the Arctic are important for considerationwhen assessing regional differences in spatial andtemporal trends of discontinued and current-use contaminants.