A review on the occurrences of persistent organic pollutants in corals, sediments, fish and waters of the Western Indian Ocean

摘要

Persistent organic pollutants (POPs) present a class of synthetic chemicals that include organochlorine pesticides, polychlorinated biphenyls and dioxins. They are characterized by environmental persistence, transboundary mobility, lipophilicity, and bioaccumulation that may induce fatality especially to top ranked biota due to biomagnification. The oceanic ecosystems are essential pools through which POPs accumulate. Despite the abundance and biotic effects caused by POPs, data on their occurrences as well as the fate of persistent organic pollutants in corals, sediments, fish and waters of the Western Indian Ocean are still scarce. The present review evaluates the status quo, equilibrium distribution of POPs among oceanic ecosystems, and future perspectives of POPs in the Western Indian Ocean. It was observed that some POPs such as DDT and PCBs reported across Africa were more of transformation products than fresh entities. Coastal corals and ocean waters were more contaminated than offshore areas as an indication of terrestrial anthropogenic-based pollution. The Indian Ocean ecosystem, especially fishes, had POPs residuals, whereby DDT and its metabolites were identified as the most frequently occurring POPs. This puts all the interacting ecosystems at high risk through biomagnification. Thus, the reduction of terrestrial contamination and monitoring the trends of POPs in oceanic compartments are necessary for the sustainability of the marine ecosystem.