Microplastics in the marine environment: Sources, Impacts & Recommendations

Abstract

Plastic pollution in the marine environment has been consistently reported since the late 1960s, however, recent evidence of global widespread microplastic pollution has led to an exponential increase in both research and policy efforts. This report reviews recent publications on the effects and impacts of microplastics in the marine environment with the aim to provide useful information for decision-makers, stakeholders, researchers working in this field, and the general public. Every effort has been undertaken here to verify valid sources of information while interacting with marine litter and microplastic experts to ensure that the most recent and reliable information available is part of this report. It is common to refer to the topic of microplastics with prudence due to the many uncertainties associated with the lack of common definitions or standardised methodologies for sampling, processing, data analysis, and reporting. However, it is important to take stock of the multiple efforts conducted thus far by many researchers throughout the world. This report does not intend to diminish the contribution that plastic as a material has made to the socio-economic development of our species or the immense added value it has contributed to several research fields including medicine and computing. The future challenges associated with plastic pollution lie in the distinction between essential and non-essential single-use items; on efficient and adequate global solid waste and wastewater management; and on eco-design approaches that follow universal circular economy principles. The combination of responses to these challenges will lead to the reduction of the enormous quantities of plastic that are accidentally or intentionally disposed of in the marine environment, every year. For this report, two main definitions are of particular importance. The first one is marine litter, defined by the Marine Strategy Framework Directive (2008/56/EC) as: “any persistent, manufactured or processed solid material that is deliberately or unintentionally discarded, disposed of, abandoned or transported by winds, rivers and animals into the marine and coastal environment”. The second definition is microplastics, here following Frias and Nash, 2019, and defined as “any synthetic solid particle or polymeric matrix, with regular or irregular shape and with size ranging from 1 μm to 5 mm, of either primary or secondary manufacturing origin, which are insoluble in water”. This report focuses on both primary and secondary microplastics, meaning, plastic items that are produced to have microscopic dimensions or that result from the fragmentation and degradation of larger items, respectively. This report focuses on the marine environment and is divided into four chapters which address the (1) scale of the marine microplastic pollution through its sources and pathways, (2) the known and most important impacts, (3) future monitoring based on expert opinion and a final chapter on (4) recommendations to minimise and mitigate the plastic problem. It is the authors’ intention that the report stimulates dialogue among stakeholders and decision-makers, and that by doing so, this will lead to awareness-raising and prompt action, particularly towards phasing out non-essential single-use items and intentionally added microplastics in personal care and other relevant consumer products; as well as promoting eco-design approaches that allow plastics to fully move towards a circular economy paradigm.

It is time to flatten the plastic curve.