The assessment of the bioaccumulation of microplastics in key fish species from the Bulgarian aquatory of the Black Sea

One of the main problems of the world's oceans, reported by many scientific studies, is the microplastic pollution. Within the Black Sea, one of the main sources of pollution is the same, which is caused by the diverse anthropogenic activities. The present study demonstrated detailed microplastics contamination of in five fish species important for the commercial fishing (Garfish, Мullet, Knout goby, Pontic shad and Mediterranean horse mackerel). They were collected from the Sozopol area on the Bulgarian Black Sea coast. Within each microplastic morphological group, three size classes were recognised: 100–200 µm, 25–100 µm and ≤ 25 µm. Microplastics were found in all studied tissues of the fish, but in varying proportions of pellets, fibres and fragments. Pellets were most frequently isolated, followed by irregularly-shaped fragments and fibres were the least numerous. The bulk of insulated plastics are made of polyethylene (PE) and polyethylene terephthalate (PET). Our results pointed out serious pollution with plastic particles in the Bulgarian Black Sea aquatory, which, in the future, may seriously affect the health of the fish population and also human health.