Monitoring of Seafloor Litter on the Dutch Continental Shelf : International Bottom Trawl Survey 2026, Dutch Beam Trawl Survey 2025

This report presents the seafloor litter composition, abundance, and spatial distribution based on catches of the regular fish surveys; the IBTS and the Dutch Beam Trawl Survey (BTS). Only the catches on the Dutch Continental Shelf (DCS) are used for data analysis. To assess the status of seafloor litter on the DCS, the Dutch data are supplemented with those from international partners surveying the DCS within the IBTS.

The seafloor litter catches on the DCS consisted mainly of plastic items, accounting for 86% of the litter found in the IBTS and 83% in the BTS. The most commonly caught items were monofilaments, plastic sheets, and various types of (plastic) ropes and lines.