Mediterranean marine biodiversity under threat: Reviewing influence of marine litter on species

• Review of available quantitative data on marine litter in the Mediterranean basin.
• Reviewing main litter types according to groups of interactions with species and feeding strategies.
• Several taxa and species are affected by marine litter, both at water column and seafloor.
• Biodiversity is under threat with key species under protection particularly influenced by marine litter.

The Mediterranean Sea is one of the most polluted seas worldwide, especially with regard to plastics. The presence of this emerging man made contaminant in marine environments precludes large effects and interactions with species exposed to massive litter quantities. In this review, available data of floating and seafloor litter around Mediterranean sub-basins are reported. A review of scientific literature on the interaction of plastic with marine biota resulted in the identification of 134 species, several taxa and feeding strategies affected from 1986 to 2014. Data from 17,334 individuals showed different levels of ingestion and effects on catalogued IUCN species (marine mammals and sea turtles) in addition to several pelagic fish and elasmobranchs. Biodiversity is certainly under threat, and knowledge of the extent of taxa affected is of concern considering the increasing plastic loads in the Mediterranean Sea and worldwide.