Microplastic Abundance and Polymer Types in a Mediterranean Environment

Microplastics have become a more and more dominant threat to marine ecosystems. The ubiquity of microplastics is one of the major problems; from the sea surface and water column to the beach and seabed sediment or even ingested by marine organisms, small plastic particles have been found. This study is focused on monitoring and assessment of microplastic pollution (plastic particles <5 mm) on the sea surface, in beach sediments, and in marine biota in the Corfu Island area (Northern Ionian Sea). Microplastics detected in samples from water, sediment, fish gut or mussel tissue were stereoscopically observed, categorized by shape, size, colour and their polymer type was identified by FTIR analysis. Microplastic items in sea surface water ranged from 0 to 1.61 particles/m2. Microplastics average abundance in beach sediments ranged from 17 to 95 items/m2. Out of all fish and mussels tested, the percentage of individuals detected with microplastics was 41.25% and 46.25% respectively. The average abundance of small microplastics (<1 mm) in positive fish and mussels was 1.66 particles/fish and 1.83 particles/mussel, while the no large microplastic (1–5 mm) was detected. The majority of microplastics in all environmental compartments were identified as polyethylene. Relations in size classes and polymer type among environmental compartments are investigated. Results describe a holistic image of the pollution caused by microplastics in the study area and can be useful for an integrated microplastic monitoring.