Working Group on the Effects of Extraction of Marine Sediments on the Marine Ecosystem (WGEXT; outputs from 2025 meeting)

The Working Group on the Effects of Extraction of Marine Sediments on the Marine Ecosystem (WGEXT) develops the understanding to ensure that marine sand and gravel extraction is sustainably managed and in order to adopt mitigative measures.The WGEXT has been monitoring the rate of marine sediment extraction in the North Atlantic, including the Baltic and North Sea for almost 40 years. The group has now established a database and repository of associated material - North Atlantic Marine Aggregates Application (NAMAAP, https://rconnect.cefas.co.uk/wgext_dash/) - to document current extractions by end use, leased areas and, where possible, the footprint of dredged areas, all in the perspective of the long-term trends since 1993. Although not all member countries provide annual data, the WGEXT inventories are representative of activity in the ICES region. Volumes extracted have shown a spectacular increase from a few hundred thousand m³ per year in the early 1970s to millions m³ in the 1990s and tens of millions m³ in recent years. Over the last thirty-five years, the demand for sand for beach nourishment and shore protection has increased substantially. Sand is now recognised as a critical, strategic resource. Areas actually dredged in any year are much smaller than the areas licensed. The active areas and even the intensity of dredging can be determined either by Electronic Monitoring System (EMS) or Automatic Identification System (AIS) to define a dredging footprint. While still in a developmental stage, AIS algorithms can be trained using EMS data with a view to expand understanding of the spatial footprint of marine aggregate dredging.The competition for access to marine resources, including space, continues to grow. Accommodation for marine sand not only impacts with fisheries and habitat concerns, but also the space needed to accommodate offshore windfarm and cable routes. Infrastructure of this nature has the potential to ‘sterilise’ areas of the sea floor such that the sediment resources are not available for exploitation.