No abstract

No abstract

No abstract

Coastal waters worldwide are widely contaminated with various-size plastics, whose presence in aquatic ecosystems has been shown to produce a wide range of economic and social impacts and harmful effects on marine ecosystems. While microplastics have been reported from many regions of the Mediterranean Sea, very few data exist regarding microplastics concentration in Algerian waters. In this study, we used a Manta trawl (330 µm) at six sampling stations in Bou-Ismail Bay, Algeria (South-West Mediterranean Sea) in order to provide novel information about the occurrence and composition of microplastics along the Algerian coast. Sampling was performed seasonally at six different sampling stations in 2018, providing additional information about the spatio-temporal variability of microplastics concentrations at the sea surface. Microplastics were found in all collected samples, with highly variable concentrations of 0.95, 0.88, 1.26, and 0.36 items/m3 in Autumn, Winter, Spring and Summer, respectively, and an overall mean concentration of 0.86 ± 0.35 items/m3. A classification based on the shape and appearance of microplastics indicated the predominance of fibers (32%), followed by fragments (27%), films (16%), foams (13%), and granules (12%). A qualitative microplastics analysis through Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR) revealed that microplastics were mainly composed of polyethylene (68.2%), polypropylene (24.7%), polystyrene (4.1%) and other polymers (3%). These data provide an initial overview of the quantity, characteristics, and spatio-temporal distribution of floating microplastics in Bou-Ismail Bay (Algeria).

Résumé :Comme tous les ports algériens, le port de Ténès souffre d'un ensablement accru, par sa situation géographique (compris entre deux grands cours d'eau), il est soumis à des apports importants de sédiments d'autant plus qu'il possède deux passes d'entrée. Les activités économiques du port, les travaux de carénage des bateaux ainsi que les différents rejets effectués au niveau port introduisent des polluants au niveau des sédiments du port. Cette pollution des sédiments pourrait poser un problème quant au devenir des produits de dragage (METAP, 1994). Les ports qui sont des milieux fermés, favorisent la sédimentation des sédiments et en particulier la fraction fine qui constitue un piège pour les métaux lourds. Le but de ce travail est de connaitre d'une part, la granulométrie des sédiments du port et d'autre part connaitre la concentration de quelques métaux lourds.