Microplastics are tiny plastic particles up to 5 mm in diameter. In the last four decades, concentrations of these particles appear to have increased significantly in the surface waters of the ocean.
Concern about the potential impact of microplastics in the marine environment has gathered momentum during the past few years. The number of scientific investigations has increased, along with public interest and pressure on decisionmakers to respond.
Despite a rapidly growing knowledge base, the extent to which microplastics represent a hazard to marine life – and may provide a pathway for transport of harmful chemicals through the food web – is still being assessed. A number of international initiatives are under way to determine the physical and chemical effects of microplastics in the ocean, and to identify ways to address this emerging issue.