Search

Marine plastic pollution represents a major problem owing to its increasing presence in the environment, persistence and ability to spread in every compartment in the form of small plastic particles, namely microplastics (MPs). Studies concerning MPs abundance in the Mediterranean Sea are growing, but their occurrence in the Southern regions remains largely unexplored. In this study, distribution, abundance, size, and polymer type of microplastics were investigated in surface water samples collected with a Manta net (200 μm mesh size) and in 118 marine specimens of commercial interests, including fishes, crustaceans, and mollusks, during Spring and Autumn 2019 EU H2020 Claim Project sampling Campaigns in the Gulf of Gabes (Southern Mediterranean Sea). Laboratory characterization showed significant plastic pollution concentrations, with an average abundance of 312,887 and 77,110 items/km2 in surface water samples collected in Spring and Autumn, respectively. A 3D hydrodynamic and Tracking Model was used to identify dispersal and transport pathways of the floating plastics, reporting a seasonal variability observed in MPs distribution between I (Spring) and II Campaign (Autumn). Despite the high values of MPs abundance found in surface water samples, an overall low frequency of ingestion among studied species was observed, with a maximum value of 20% of individuals (in Scomber scombrus) found with ingested MPs. The present study contributes to expand our state of knowledge regarding MPs pollution level in water and biota samples collected in the Gulf of Gabes, an area of particular interest for its biological resources, but still little investigated.

In this study, the abundance and properties (size, shape, and polymer type) of microplastics (MPs) in sea surface water samples, collected during two sampling campaigns over 2018–2019, in four coastal areas of the Mediterranean Sea (Saronikos Gulf, LIgurian Sea, Gulf of Lion, and Gabes Gulf) were investigated. Coupled hydrodynamic/particle drift model simulations with basin-scale Mediterranean and high resolution nested models were used to provide a better understanding on the variability of the abundance/size of MPs, originating from wastewater and river runoff, in the four areas. Different size classes of MPs were considered in the model, taking into account biofouling induced sinking, as a possible mechanism of MPs removal from the surface. The Gabes Gulf showed the highest mean MPs abundance (0.073–0.310 items/m2), followed by Ligurian Sea (0.061–0.134 items/m2), Saronikos Gulf (0.047–0.080 items/m2), and Gulf of Lion (0.029–0.032 items/m2). Overall, the observed MPs abundance and size distribution was reasonably well reproduced by the model in the four different areas, except an overestimation of small size contribution in Saronikos Gulf. The basin-scale simulation revealed a strong decrease of smaller size MPs in offshore areas, due to biofouling induced sinking, with larger (floating) MPs being able to travel longer distances in the open sea. A significant impact of waves drift and advection of MPs from non-local sources was identified from model simulations, particularly in the Gulfs of Lion and Gabes, having a stronger effect on larger microplastics. In Gabes Gulf, most MPs originated from offshore areas, being mainly (floating) larger size classes, as suggested by the observed quite small contribution of