Persistent organic pollutants in ocean sediments from the North Pacific to the Arctic Ocean

Ma, Yuxin and Halsall, Crispin and Crosse, John and Graf, Carola and Cai, Minghong and He, Jianfeng and Gao, Guoping and Jones, Kevin (2015) Persistent organic pollutants in ocean sediments from the North Pacific to the Arctic Ocean. Journal of Geophysical Research: Oceans, 120 (4). pp. 2723-2735. ISSN 8755-8556

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Abstract

Concentrations of polychlorinated biphenyls (PCBs), organochlorine pesticides (OC pesticides), and polybrominated diphenyl ethers (PBDEs) are reported in surficial sediments sampled along cruise transects from the Bering Sea to the central Arctic Ocean. OCs and PCBs all had significantly higher concentrations in the relatively shallow water (<500 m depth) of the Bering-Chukchi shelf areas (e.g., ΣPCB 286 ± 265 pg g−1 dw) compared to the deeper water regions (>500 m) of the Bering Sea and Arctic Ocean (e.g., Canada Basin ΣPCB 149 ± 102 pg g−1 dw). Concentrations were similar to, or slightly lower than, studies from the 1990s, indicating a lack of a declining trend. PBDEs (excluding BDE-209) displayed very low concentrations (e.g., range of median values, 3.5–6.6 pg/g dw). In the shelf areas, the sediments comprised similar proportions of silt and clay, whereas the deep basin sediments were dominated by clay, with a lower total organic carbon (TOC) content. While significant positive correlations were observed between persistent organic pollutant (POP) concentrations and TOC (Pearson correlation, r = 0.66–0.75, p <0.05), the lack of strong correlations, combined with differing chemical profiles between the sediments and technical formulations (and/or marine surface waters), indicate substantial chemical processing during transfer to the benthic environment. Marked differences in sedimentation rates between the shallow and deeper water regions are apparent (the ∼5 cm-depth grab samples collected here representing ∼100 years of accumulation for the shelf sediments and ∼1000 years for the deeper ocean regions), which may bias any comparisons. Nonetheless, the sediments of the shallower coastal arctic seas appear to serve as significant repositories for POPs deposited from surface waters.

Item Type:
Journal Article
Journal or Publication Title:
Journal of Geophysical Research: Oceans
Additional Information:
© 2015. The Authors. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.
Subjects:
ID Code:
73569
Deposited By:
Deposited On:
14 Apr 2015 09:58
Refereed?:
Yes
Published?:
Published
Last Modified:
15 Jul 2020 04:54