Microplastics occurrence in fish with different habits from the central Tyrrhenian Sea

Abstract

Both marine environment and biota are affected by microplastics, thus requiring a punctual and continuous monitoring of their presence and impacts. The number of studies analysing microplastics in vertebrates and invertebrates is continuously growing, but few generalizable patterns have been evidenced to date. This work explores some emerging hypotheses using data from four different fish species sampled in the same locality off Mediterranean central Tyrrhenian coasts: if ingestion rate in fish can be affected by both species-specific feeding preferences and vertical distribution; and if a relationship between fish size and abundance of ingested microplastics occurs. The results obtained showed no significant differences in the microplastics quantity recorded in pelagic, benthopelagic or demersal species. However, our data suggest that predator species may be attracted by microplastics similar to their natural prey for colour, since the piscivorous Mediterranean horse mackerel (Trachurus mediterraeus) showed a significant relationship between size and blue fibres. More broadly, our findings evidenced a correlation among fish size and both fibres and films ingested. A comparison of the microplastics occurrence reported across the Mediterranean Sea for the same species showed deep differences which can be explained by both the uneven concentration of microplastics across the basin and the different recovery methods used in the various studies.