Why Do Organochlorine Differences between Arctic Regions Vary among Trophic Levels?

• Published in: Environmental science & technology Vol. 39; no. 12; pp. 4343 - 4352
• Main Authors: Borgå, Katrine, Gabrielsen, Geir Wing, Skaare, Janneche Utne, Kleivane, Lars, Norstrom, Ross J, Fisk, Aaron T
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 15.06.2005
• Subjects: Analysis of Variance; Animal, plant and microbial ecology; Animals; Applied ecology; Arctic Regions; Biological and medical sciences; Boreogadus saida; Chemical contaminants; Chlorine; Ecosystem; Ecotoxicology, biological effects of pollution; Environmental Monitoring - methods; Environmental Monitoring - statistics & numerical data; Environmental Pollutants - analysis; Food Chain; Food chains; Fundamental and applied biological sciences. Psychology; Gas Chromatography-Mass Spectrometry; Hydrocarbons, Chlorinated - analysis; Lipids - analysis; Mammalia; Marine; Marine and brackish environment; Marine mammals; Nitrogen Isotopes - analysis; Phoca hispida; Plankton; Statistical analysis; Trends; Vertebrates - metabolism; Vertebrates: general zoology, morphology, phylogeny, systematics, cytogenetics, geographical distribution; Zooplankton - metabolism; Arctic Ocean; Arctic Region; Barents Sea; Baffin Bay; Arctic Regions; Arctic region; PNE, Barents Sea; PNE, Europe; Arctic; PN, Arctic; PNW, North America; Statistical analysis; Climatic zone; Trophic chain; Pollutant; Vertebrata; Mammalia; Plankton; Trophic level; Organochlorine compounds; Chlorine Organic compounds; Pisces; Polar region; Aves; Zooplankton; Geographical variation; Organic compounds; Chemical contamination
• ISSN: 0013-936X; 1520-5851
• DOI: 10.1021/es0481124

Statistical analysis of organochlorine contaminants (OCs) in marine mammals has shown that, for most OCs, the European Arctic is more contaminated than the Canadian and U.S. Arctic. Recently, comparison of OC concentration ranges in seabirds, arctic cod (Boregadus saida), and zooplankton, found no difference between these regions. To address these inconsistencies, marine food web OC data from the European (central Barents Sea (CBS)) and Canadian Arctic (Northwater Polynya (NOW)) were simultaneously statistically analyzed. In general, concentra tions 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 marine mammals. In contrast, levels of OCs were generally similar in zooplankton and arctic cod between the CBS and NOW. The main exception is HCH which had greater levels in the NOW across all trophic levels because of the greater proximity to sources in eastern Asia. The lack of differences in OC concentrations in zooplankton and Arctic cod from the European and Canadian Arctic suggest that regional differences in OC contamination in the Arctic have evened out. Reduced regional differences were not observed in marine mammals or seabirds because they are long-lived and also acquire contaminants from maternal transfer and hence reflect levels from the past when the European Arctic was more contaminated than the Canadian Arctic. In addition, seabirds may reflect exposure from other areas. This study highlights the potential problem of comparing spatial trends by using means and confidence intervals as compared to simultaneous statistical analysis of raw data. Differences in the spatial trends of OCs between trophic levels in the Arctic are important for consideration when assessing regional differences in spatial and temporal trends of discontinued and current-use contaminants.