Standardised protocol for monitoring microplastics in sediments. Deliverable 4.2.

Marine anthropogenic litter has long been recognised as an emerging pollutant of global concern. Its ubiquitous distribution and its direct and indirect impacts on aquatic ecosystems, marine fauna and local economies have been recently highlighted by several studies and international organisations around the world. Although comprised of different materials, plastic constitutes the most abundant fraction reported in worldwide surveys, with percentages that are variable from region to region. Among plastic materials, microplastics (herein MPs), represent a huge concern due to their impacts resulting from fragmentation under weathering conditions (e.g. solar radiation, water temperature and abrasion processes) and from their ability to adsorb persistent, bioaccumulative and toxic chemicals (PBTC) (e.g. polychlorinated biphenyls - PCBs, polycyclic aromatic hydrocarbons – PAHs) and trace elements (e.g. Cu, Zn, etc.). In addition to these impacts, recent studies have also reported the potential for MPs to be easily mistaken as food particles and subsequently ingested by a wide range of organisms throughout the different environmental compartments (e.g. sediment, water, air). Under the scope of the JPI-Oceans, BASEMAN is an international and interdisciplinary collaborative research project that aims to overcome the lack of standardised methodologies through a profound and detailed comparison and evaluation of all approaches from sampling to identification of MPs. The two overall goals of the project are firstly “The validation and harmonisation of analytical methods” which is indispensable for the second goal of “Identification and quantification of MPs”. Based on these goals and with the overall aim of creating a standardised methodology to allow microplastics harmonised long-term monitoring in Europe, the BASEMAN project provides a set of recommended protocols to allow comparisons among studies. With this in mind, the protocols will focus on sampling, processing and analysis of MPs in samples from different environmental compartments, specifically addressing MPs from intertidal and subtidal sediments. This protocol is aimed at improving sampling, processing and MPs data collection quality while also allowing comparison amongst different studies throughout Europe.