Standardised protocol for monitoring microplastics in seawater. Deliverable 4.1.

Microplastic litter is an omnipresent pollutant in marine systems across the globe; spread out from the water surface to benthic sediments. Furthermore, the current trend of microplastic accumulation in the marine environment will enable these particles to remain there for centuries to come, due to their persistence. Nevertheless, the impact of plastic particles on aquatic ecosystems is far from being understood. The consequences are estimated to be severe as microplastics can accumulate persistent organic pollutants from the environment and release toxic additives into the environment, which might pose a threat to marine organisms upon ingestion. Although microplastics are recognised as a contaminant of emerging concern in the environment, currently neither sampling, extraction, purification nor identification approaches are standardised, making microplastic studies difficult to compare, if at all, possible. Harmonization of protocols for determination of plastic particles is urgently needed in order to overcome this gap. The JPI-Oceans BASEMAN project is an interdisciplinary and international collaborative research project that aims to overcome this problem and to undertake a profound and detailed comparison and evaluation of all approaches from sampling to identification of microplastics. The two overall goals of the project are the “The validation and harmonisation of analytical methods” which is indispensable for the “Identification and quantification of MP”. The BASEMAN project will try to answer questions like the abundance and distribution of microplastics in the environment. For this purpose, tools and operational measures will be proposed so that they allow evaluation Member States’ compliance with existing and future monitoring requirements. This document regards microplastic sampling, processing and analysis for surface and water column seawater samples.