Preliminary Assessment of Microplastic Accumulation in Wild Mediterranean Species

Because of their abundance, persistence, and ubiquity, microplastics (MPs) represent a serious environmental risk, recognized even by the European Union which calls for further investigation. The Mediterranean basin seems to be highly affected by microplastic pollution, and it has been considered the sixth great accumulation area for marine litter. Polyethylene (PE) and polypropylene (PP) are the main polymers found in the Mediterranean Sea, followed by a “soup” of many other synthetic polymers. While it is known the impact caused by the largest pieces of plastic debris and ghost fishing on mega-fauna such as seabirds, turtles, and cetaceans, the knowledge of environmental effects of microplastics—plastic particles 5 mm diameter, as defined by NOOA—is still limited. Recently, several studies showed that ingestion of microplastics is commonplace throughout marine ecosystems, but the effects on health status of marine wildlife, or the impact to higher trophic levels through biomagnification is still to understand. In this study, we carried out a preliminary assessment of the ingestion of microplastics in a wild fish species, namely the red mullet Mullus barbatus, of economic and ecologic interest in the Mediterranean basin. For the first time, we searched for microplastics not only in the stomach contents, but also in the gills, in order to understand if these tissues could represent a further route of entry of MPs in biological systems.