Sources, distribution and impacts of microplastics in the marine environment: an overview of the results of JPI Oceans projects

Plastics are extremely versatile materials used in a wide range of applications that support human activities and make our lives easier. However, increasing population growth, excessive consumption, and poor waste management have transformed these materials into an environmental threat. This research integrates findings from six European projects investigating sources, distribution, and impacts of plastics in aquatic and marine environments, with a particular focus on the Atlantic Ocean and on the North, Baltic, and Mediterranean Seas. The projects assessed key detection methods, pollution sources, distributions, accumulation, pathways, and impacts of plastics and microplastics, including novel aspects related to risk assessment using ecotoxicological data, nanoplastic detection in natural environments, assessment of eco-corona layers on submerged microplastics, and identification of accumulation hotspots in European waters. The geographical coverage of the projects also extended to areas along the Atlantic, African, and South American coasts. The studies investigated a range of plastic polymers, including conventional polymers and bioplastics, showing little differences in accumulation of organic and inorganic pollutants among them. Ecological risk assessment and ecotoxicology studies identified the dynamic nature of interactions between plastics and environmental matrices, and the release of leachates or adsorption of persistent organic pollutants and trace metals to the biofilm layers. The six projects identified new risks to ecosystem and human health, particularly regarding invasive species and toxicological impacts. All the projects participated in communication activities, fostering collaborations and enhancing public outreach. Policy recommendations emphasise the urgent need to regulate production and increase recycling efficiency to meet Paris Agreement targets, to regulate intentionally added chemicals to reduce potential human health risks, and to mitigate the spread of invasive species by intercepting items before they reach the open ocean. These insights support the development of policies that effectively manage marine plastic pollution and protect ocean & human health.