Detection of microplastics, polymers and additives in edible muscle of swordfish (Xiphias gladius) and bluefin tuna (Thunnus thynnus) caught in the Mediterranean Sea

The Mediterranean Sea is particularly endangered by microplastics (MPs), polymers, and additives. These contaminants can be ingested by fishes and, hence, translocate into tissues. We aimed to quantify MPs, polyethylene terephthalate (PET), polycarbonate (PC), bisphenol A (BPA), and p-phthalic acid (PTA) in the edible muscles of swordfish (Xiphias gladius) and bluefin tuna (Thunnus thynnus) caught in the Mediterranean Sea. The MPs were extracted from muscles and characterized by stereomicroscopy and Raman microspectroscopy, while the polymers (PET and PC) and additives (BPA and PTA) were identified by LC-MS/MS. The number of MPs ranged from 140 to 270 no. kg−1 in swordfish and from 160 to 270 no. kg−1 in tuna. The most frequent MP polymer was polypropylene in swordfish (33%) and in tuna (34.7%), while the most abundant pigments were PB115, PB116, PBr101/102. A similar level of plastic contamination was revealed in these two fish species with differences in shapes, colors, pigments and polymers of MPs.