Abstract

Since the 1950s, the quantity of plastic being manufactured has continued to increase leading to a growing environ-mental problem. While macroplastics (plastics bags, bottles...) are easily detectable in marine areas, microplastics (particles <500?m) are invisible to the naked eye. Microplastics result from the degradation of macroplastics or are initially synthe-tized as microparticles. When ingested by marine organisms, these small pieces of plastics can block feeding appendages, hinder the passage of food through the intestinal tract or cause pseudo-satiation resulting in reduced food intake. Microplastics are found in various aquatic environment (rivers, lakes and ocean) and different matrix (fauna, seawater). In the present study, the contamination of marine sediment in coral reef systems was investigated around Guadeloupe Island.Among the three methods tested to extract microplastics from sediments, the use of a saturated solution of NaCl was found to be the most efficient one. The number of microplastics, principally fibers, varied from 0.7 to 4.6 per gram of sediment and differed significantly according to the site. The level of contamination can be explained by the distance of the sites from harbors and urbanized areas. Microplastics, as organic molecules, can adsorb hydrophobic pollutants ins seawater. In Guadeloupe, a part of the natu-ral environment is impacted by chlordecone, a highly toxic organochlorine pesticide used in banana plantations until 1993. The adsorption of chlordecone on microplastics was studied on three sites and adsorbed chlordecone was found in all the samples analyzed. It is the first report of adsorbed chlordecone on microplastics in marine sediments on Guadeloupe and this observation suggests a new way of contamination of marine trophic food-webs.

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