ICES Manual for Seafloor Litter Data Collection and Reporting from Demersal Trawl Samples

Update (16/10/2023): Manual updated to reflect the implementation of the reference code C-TS-REV-2, which, in contrast to C-TS-REV, contains litter categories A15 and A16.

Corrigendum (12.01.2023): Correction to the naming of categories A5 and A6.

Multiple seafloor litter monitoring programmes are in place within Europe, during which the litter caught as bycatch in fishing nets from fish stock survey trawls are collected and recorded. This manual provides user-friendly instructions for ships’ crew and researchers collecting and recording seafloor litter. Essential information on how to categorize, count, weigh, and measure seafloor litter items is provided. Ambiguous names within litter categories are clarified and guidance is provided on specific issues such as the proper classification of items made up of multiple materials. A supplementary photo guide is provided to facilitate the litter identification and registration process, with clear pictures of example items from every litter subcategory. Finally, the reporting of marine litter data is described, including all required information to obtain a quality assured dataset. The use of this manual will help harmonize litter collection and reporting procedures, enhancing the quality of monitoring data. Adherence to the instructions is mandatory for survey trawls submitting data to the Database of Trawl Samples (DATRAS) and coordinated by the International Council for the Exploration of the Sea (ICES). The use of these instructions is optional for all other research and monitoring surveys.