Oceanic Sink and Biogeochemical Controls on the Accumulation of Polychlorinated Dibenzo-p-dioxins, Dibenzofurans, and Biphenyls in Plankton

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• 作者：Laura Morales ; Jordi Dachs ; Mar铆a-Carmen Fern谩ndez-Pinos ; Naiara Berrojalbiz ; Carmen Mompean ; Bel茅n Gonz谩lez-Gaya ; Bego帽a Jim茅nez ; Antonio Bode ; Manuela 脕balos ; Esteban Abad
• 刊名：Environmental Science & Technology
• 出版年：2015
• 出版时间：December 1, 2015
• 年：2015
• 卷：49
• 期：23
• 页码：13853-13861
• 全文大小：582K
• ISSN：1520-5851

文摘

Polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (dl-PCBs) were measured in plankton samples from the Atlantic, Pacific, and Indian Oceans collected during the Malaspina circumnavigation cruise. The concentrations of PCDD/Fs and dl-PCBs in plankton averaged 14 and 240 pg g_dw^鈥?, respectively, but concentrations were highly variable. The global distribution of PCDD/Fs and dl-PCBs was not driven by proximity to continents but significantly correlated with plankton biomass, with higher plankton phase PCDD/F and dl-PCB concentrations at lower biomass. These trends are consistent with the interactions between atmospheric deposition, biomass dilution, and settling fluxes of organic matter in the water column (biological pump), as key processes driving POPs plankton phase concentrations in the global oceans. The application of a model of the air鈥搘ater鈥損lankton diffusive exchange reproduces in part the influence of biomass on plankton phase concentrations and suggests future modeling priorities. The estimated oceanic sink (Atlantic, Pacific, and Indian Oceans) due to settling fluxes of organic matter bound PCDD/Fs and dl-PCBs is of 400 and 10,500 kg y^鈥?, respectively. The atmospheric inputs due to gross diffusive absorption and dry deposition are nearly 3 and 10 times larger for PCDD/Fs and dl-PCBs, respectively, than the oceanic sink. These observations suggest that the coupling of atmospheric deposition with water column cycling supports and drives the accumulation of dl-PCBs and PCDD/Fs in plankton from the global oligotrophic oceans.