Microplastics in jellifying algae in the Bay of Biscay. Implications for consumers' health

Abstract

Microplastics pollution is widespread throughout the world, affecting all marine ecosystems and their organisms. The red alga Gelidium sp. is the source of best quality agar and is directly consumed as seafood in many countries. Here we quantified microplastics in Gelidium corneum harvested along the Asturias coast (southwest Bay of Biscay) from locations differently affected by factors that influence microplastics concentration like substrate size, ports, rivers, etc. Results showed that G. corneum collected near sandy substrates accumulates more microplastics than those from rocks, suggesting that the substrate's dynamics is key to allow microplastics to reach these algae and enter the human diet. Considering their composition, polyethyleneimine and polyester were identified and classified as harmful according to the European Chemicals Agency. The polyethyleneimine is present in the 28,6 % analysed from the algae and may pose a risk to consumers. The amount of microplastics potentially ingested by consumers would be lower than mussels and eels of the same region; but could potentially increase in agar if microplastics are not retained during processing. More research to identify microplastics sources and measures to prevent them in coastal areas are recommended.