Spatial trends and bioaccumulation of organochlorine pollutants in marine zooplankton from the Alaskan and Canadian Arctic

• Published in: Environmental Toxicology and Chemistry
• Main Authors: Hoekstra, Paul F., O'Hara, Todd M., Teixeira, Camilla, Backus, Sean, Fisk, Aaron T., Muir, Derek C. G.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2002
• Subjects: Arctic; Calanus glacialis; Zooplankton; Copepods
• Online Access: http://dx.doi.org/10.1002/etc.5620210316; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fetc.5620210316; https://setac.onlinelibrary.wiley.com/doi/pdf/10.1002/etc.5620210316

Abstract Planktonic copepods ( Calanus glacialis and C. hyperboreus; n = 37) and water ( n = 19) were collected to examine the spatial distribution and bioaccumulation of organochlorine contaminants (OCs) in the Alaskan and Canadian Arctic. The rank order of total OC (σ OC) group concentrations in Calanus samples was toxaphene ≥ σ polychlorinated biphenyls (PCBs) > σ hexachlorcyclohexane (HCH). σ DDT > σ chlordane‐related compounds (CHLOR) > σ chlorobenzenes (ClBz). The dominant analyte was α‐HCH in all water and zooplankton samples. The most abundant toxaphene congener in water and zooplankton samples was the hexachlorobornane B6‐923. Organochlorine contaminant group concentrations in Alaskan zooplankton and water samples were lower than those in samples collected from sites in the eastern Canadian Arctic. Comparison of PCB and toxaphene congener profiles in zooplankton and water samples suggests that biotransformation by cytochrome P‐4502B isozymes is low in Calanus , and limited phase I metabolism may occur. The log relationship of bioaccumulation factor (log BAF) versus octanol‐water partition coefficient (log K ow ) relationship was near 1: 1 for OCs within the log K ow range of 3 to 6. A curvilinear model provided a better relationship between these two variables when OC compounds with log K ow > 6 were included. These results suggest that hydrophobic OCs (log K ow 3‐6) in Calanus species are at equilibrium with the water concentrations and that physical partitioning, rather than biotransformation, is the major factor governing OC profiles in marine zooplankton.