Seasonal occurrence and distribution of microplastics in four different benthic suspension feeders from an IMTA facility: a bioremediation perspective

Microplastics (MPs) are dangerous and ubiquitous in the environment. The urgency to contrast plastic pollution is prompting the scientific community to offer new proposals. Recently, bioremediation using filter feeders is gaining consent as a nature-based solution. Herein four filter feeders (Mytilus galloprovincialis Lamarck, 1819, Sabella spallanzanii Gmelin, 1791, Phallusia mammillata Cuvier, 1815, Paraleucilla magna Klautau, Monteiro & Borojevic, 2004), studied in a previous laboratory experiment as MPs bioremediators, are evaluated in field conditions within 1-year. These organisms are part of an established fouling community growing on eco-friendly ropes in an Integrated Multi-Trophic Aquaculture (IMTA) in the Mar Grande of Taranto. After digesting the animal tissue, the MPs content was quantified by optical microscopy and spectroscopically characterized in the four seasons: highest values were measured in Autumn and lowest in Spring. M. galloprovincialis and P. mammillata were the most contaminated, but S. spallanzanii removed more MPs, due to its high density on the ropes. The whole community removed 3.15 × 107 MPs/season, with the amount of microfibers corresponding to a bottle cap/season.