This manual adds to a number of guidance manuals for research and monitoring of plastic debris in marine environments. These include general guidance for research design, collection and reporting protocols across multiple habitat types (including biota) and are designed to be applicable across broad geographies (i.e. regional jurisdictions). However, most of these manuals and guidance documents do not specifically focus on microplastics, though they include this size category within their broader framework of plastics reporting.
Notable manuals or guidance documents include:
1) Joint Group of Experts on the Scientific Aspects of Marine Environmental Protection (GESAMP): Guidelines for the Monitoring and Assessment of Plastic Litter in the Ocean (2019).
The Joint Group of Experts on the Scientific Aspects of Marine Environmental Protection (GESAMP)’s “Guidelines for the Monitoring and Assessment of Plastic Litter in the Ocean” is the premier guidance document, compiled by international experts for designing marine debris monitoring and research programs, with a focus on litter of all sizes, including microplastics. Its main purpose is to provide recommendations, advice and practical guidance, for the establishment of programs to monitor and assess the distribution and abundance of plastic litter, also referred to as plastic debris, in the ocean. This guidance document does not prescribe specific one-size-fits-all methods but rather presents a menu of different approaches and guidance for different research questions, covering seawater, sediment and biota. The GESAMP document intends to promote a more harmonised approach to the design of sampling programs, the selection of appropriate indicators (i.e. type of sample), the collection of samples or observations, the characterisation of sampled material, dealing with uncertainties, data analysis and reporting the results and also to inform the establishment of national and regional field monitoring programs. Guidelines for the Monitoring and Assessment of Plastic Litter in the Ocean | GESAMP
2) National Oceanic and Atmospheric Administration (NOAA) Marine Debris Program: Marine Debris Monitoring and Assessment Project (MDMAP) (2021).
The NOAA Marine Debris Program coordinates the Marine Debris Monitoring and Assessment Project (MDMAP), a NOAA citizen science initiative that engages NOAA partners and volunteers, and this 2021 program builds upon earlier iterations with similar goals. This program is based in the United States but these guidelines are widely used around the world by numerous countries, especially in the Americas. The MDMAP has a macro litter and shoreline focus and includes items >2.5cm. Items less than 2.5cm (including visible sized microplastics) are neither recommended to be counted nor characterised, and the MDMAP does not include a specific method for smaller items. NOAA Marine Debris Monitoring and Assessment Project Shoreline Survey Guide | OR&R’s Marine Debris Program
3) National Oceanic and Atmospheric Administration (NOAA) Marine Debris Program: Laboratory Methods for the Analysis of Microplastics in the Marine Environment (2015).
To complement its marine debris program, NOAA published a set of standard methods for the assessment of microplastics in the laboratory in 2015. The “Laboratory Methods for the Analysis of Microplastics in the Marine Environment: Recommendations for quantifying synthetic particles in waters and sediments” are a popular protocol for sampling microplastics across environments, and though they were designed for seawater and sediment, these methods can be used for other matrices (e.g., biota). However, since their publication, new techniques for microplastic quantification and characterisation have been developed and adopted. Laboratory Methods for the Analysis of Microplastics in the Marine Environment | OR&R’s Marine Debris Program (noaa.gov)
4) Guidance on the Monitoring of Marine Litter in European Seas (2023).
This 2023 “Guidance on the Monitoring of Marine Litter in European Seas” is an update to improve the harmonised monitoring of marine litter under the Marine Strategy Framework Directive, and builds on the 2013 version of “Guidance on the Monitoring of Marine Litter in European Seas” (2013 version -> JRC Publications Repository - Guidance on Monitoring of Marine Litter in European Seas (europa.eu).
This guidance document includes general approaches and prescribes standard methods for beaches, seawater, seafloor and biota, with variations for different size classes “macrolitter” (items >25mm), “mesolitter” (items 5-25mm) and microlitter (items <5mm). This methodology is broadly used by institutions within the European Union member states.
(PDF) Guidance on the Monitoring of Marine Litter in European Seas (europa.eu)
5) Commonwealth Scientific and Industrial Research Organisation (CSIRO) Global Plastic Leakage Baseline Project (2020)
Of particular note within the Australian context, the CSIRO Global Plastic Leakage Baseline Project prescribes a harmonised, stratified and representative standard methodology for monitoring marine debris across shorelines, on riverbanks, inland and at the sea surface. This standard methodology builds on earlier iterations, and has been designed to harmonise with many of the other global marine litter protocols, such as the NOAA MDMAP. This methodology records items of all visible size ranges, including microplastics that are visible to the naked eye. It has been used in all states and territories throughout Australia, and approximately 20 countries worldwide.