Monitoring plastics in rivers and lakes: guidelines for the harmonization of methodologies

More than 8,000 million metric tons of plastic have been made since the beginning of large-scale plastic production in the 1950s. As a consequence, plastic debris is present in all ecosystems, including remote locations such as mountain lakes and polar sea ice. Oceans are the most prominent example of widespread environmental plastic pollution, research, societal awareness and action have long focused on marine plastics. Information indicates that most marine plastics originate from land-based sources. Research and action have therefore been expanded to freshwater and terrestrial environments. The purpose of this report is to provide guidelines for the assessment of plastic contamination in freshwater environments. Monitoring programmes are needed to better assess the state of and trends in plastic pollution and achieve target 14.1 of the Sustainable Development Goals: “By 2025, prevent and significantly reduce marine pollution of all kinds, particularly from land-based activities, including marine debris and nutrient pollution”.