12 March 2019: The UN Environment Programme (UNEP) launched a report that provides practical guidelines and recommendations for reporting on the distribution and abundance of plastic litter and microplastics in marine environments. The report is one of several publications on the conservation and sustainable use of marine environments released by UNEP in conjunction with the fourth session of the UN Environment Assembly (UNEA-4).

The report titled, ‘Guidelines for the Monitoring and Assessment of Plastic Litter and Microplastics in the Ocean,’ aims to support organizations in marine environmental monitoring in response to the lack of an internationally agreed methodology for reporting on plastic litter and microplastics in marine environments. Harmonization of methods, it argues, is critical to understand the scale of the problem and support informed decision making. The report stresses that the need for such harmonization has become more critical with the adoption of the SDGs.

Without harmonization of the data being collected globally, the collective response to tackle the marine plastic issue will always be compromised.

SDG indicator 14.1.1 (“index of coastal eutrophication and floating plastic debris density”) measures floating plastic litter as a global indicator of marine pollution. To advance measurement of SDG indicator 14.1.1, the report supports more harmonized methods to encourage the development and implementation of regional or global monitoring programmes and facilitate exchange of monitoring results. These increased efforts are expected to help move SDG indicator 14.1.1 from a Tier III indicator (on which no internationally established methodology or standards are available) to a Tier II indicator (for which conceptually clear, established methodology and standards are available, but data are not regularly produced).

UNEP Chief Scientist, Jian Liu, stressed that “without harmonization of the data being collected globally, the collective response to tackle the marine plastic issue will always be compromised.” He said shared monitoring guidelines will produce a “clearer picture of the true scale of the problem” and enable measurement of the impact of reduction measures, such as banning single-use plastics.

The guidelines feature recommended sampling definitions for all sizes of plastic litter encountered in the marine environment and on shorelines, from plastic litter associated with biota through entanglement or ingestion to litter deposited on the seabed or floating on the sea surface. Recommendation methods also address: sample processing; physical characterization of macro-plastics; physico-chemical characterization of microplastics; analysis of chemicals associated with plastics; and biological characterization. The report’s guidelines will be considered by the Ad hoc Open-ended Expert Group on marine litter, under UNEA.

UNEA-4 is convening in Nairobi, Kenya, from 11-15 March 2019. [Publication: Guidelines for the Monitoring and Assessment of Plastic Litter and Microplastics in the Ocean] [UNEP Press Release] [SDG Knowledge Hub Story on UNEP Report on Plastics in Shallow Water Coral Reefs] [SDG Knowledge Hub Story on Women’s Role in Management of Coastal and Marine Environments] [SDG Knowledge Hub Coverage of UNEA-4] [IISD RS Coverage of OECPR and UNEA]