Latitudinal and seasonal capacity of the surface oceans as a reservoir of polychlorinated biphenyls

• Published in: Environmental pollution (1987) Vol. 128; no. 1; pp. 149 - 162
• Main Authors: Jurado, Elena, Lohmann, Rainer, Meijer, Sandra, Jones, Kevin C, Dachs, Jordi
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Oxford Elsevier Ltd 01.01.2004; Elsevier
• Subjects: Air Pollutants - analysis; Applied sciences; Atmospheric pollution; Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Exact sciences and technology; Fugacity model; Geography; Global dynamics; Marine pollution; Models, Theoretical; Natural water pollution; Oceans and Seas; PCB; Pollutants physicochemistry study: properties, effects, reactions, transport and distribution; Pollution; Pollution, environment geology; Polychlorinated Biphenyls - analysis; POP; Seasons; Seawaters, estuaries; Time Factors; Water Movements; Water Pollutants, Chemical - analysis; Water treatment and pollution; World Ocean; POP; Marine pollution; Global dynamics; PCB; Fugacity model; Spatial variability; Latitudinal variation; Environmental factor; Biomass; Modeling; Transport process; Persistent organic pollutant; Seasonal variation; Chlorine Organic compounds; Planetary scale; Ocean; Phytoplankton; Organic compounds; Fugacity; Atmospheric condition; Pollutant behavior; Biogeochemical cycle; Source sink relationship; Polychlorobiphenyl; Mixed layer; Storage; Air pollution; Water pollution; Concentration distribution
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/j.envpol.2003.08.039

The oceans play an important role as a global reservoir and ultimate sink of persistent organic pollutants (POPs) such as polychlorinated biphenyls congeners (PCBs). However, the physical and biogeochemical variables that affect the oceanic capacity to retain PCBs show an important spatial and temporal variability which have not been studied in detail, so far. The objective of this paper is to assess the seasonal and spatial variability of the ocean's maximum capacity to act as a reservoir of atmospherically transported and deposited PCBs. A level I fugacity model is used which incorporates the environmental variables of temperature, phytoplankton biomass, and mixed layer depth, as determined from remote sensing and from climatological datasets. It is shown that temperature, phytoplankton biomass and mixed layer depth influence the potential PCB reservoir of the oceans, being phytoplankton biomass specially important in the oceanic productive regions. The ocean's maximum capacities to hold PCBs are estimated. They are compared to a budget of PCBs in the surface oceans derived using a level III model that assumes steady state and which incorporates water column settling fluxes as a loss process. Results suggest that settling fluxes will keep the surface oceanic reservoir of PCBs well below its maximum capacity, especially for the more hydrophobic compounds. The strong seasonal and latitudinal variability of the surface ocean's storage capacity needs further research, because it plays an important role in the global biogeochemical cycles controlling the ultimate sink of PCBs. Because this modeling exercise incorporates variations in downward fluxes driven by phytoplankton and the extent of the water column mixing, it predicts more complex latitudinal variations in PCBs concentrations than those previously suggested. Model calculations estimate the latitudinal and seasonal storage capacity of the surface oceans for PCBs.