Research progress in transfer, accumulation and effects of microplastics in the oceans

One of the major concerns regarding the presence of plastics in ocean environments are the effects on marine biota. Plastics can be distinguished in macro-(≥25 mm), meso-(<25 mm–5 mm) micro-(<5 mm–1 µm), and nano-plastic (<1 µm) and are practically omnipresent in aquatic habitats and subject to long-range transport. The purpose of this review is to report the last findings on the release, transfer, accumulation, and effects of micro-plastics, MPs, in the oceans. MPs have the chance to adsorb different kind of organisms and compounds on their outer surface, including bacteria, viruses, algae, and abiotic substances. In this way, they can cause sever hazard once they enter the food chain. Their harm to higher organisms is discussed as well as main routes of MPs–organism interactions, i.e., ventilation, and ingestion. Potential effects on populations, communities, and ecosystems and uptake routes and transition into tissues are discussed. In consideration of the potential threats of plastic particles to ecological functions and human health risks, we recommend specific directions of future research approaches.