Working Group on the Effects of Extraction of Marine Sediments on the Marine Ecosystem (WGEXT)
Marine sediment extraction in the North Atlantic, including Baltic and North Sea has shown a spectacular increase from a few hundred thousand m³ per year in early 1970s to millions in the 1990s and tens of millions m³ in recent years.
In the strict sense, marine mineral extraction is not sustainable because the extracted minerals are lost for the marine system. In fact, the extraction of marine sediments can even cause negative effects on the marine environment by accompanied processes like the removal of sediments in-cluding benthic fauna, introducing a sand blanket in the vicinity of the extraction, introducing high concentrations of suspended matter in the surrounding area and increasing the level of underwater sound.
Nevertheless, the way the minerals are extracted can be sustainable in the sense that the negative effects on the ecosystem are minimized by mitigation measures that are beneficial for the recol-onization of the benthic fauna and recovery is fulfilled in an acceptable timeframe after extraction.
The Working Group on the Effects of Extraction of Marine Sediments on the Marine Ecosystem (WGEXT) is mainly focused on the exchange and dissipation of information. This is reflected in the composition of the group. Not only scientists, but also representatives from governmental bodies, NGO’s and industry are participating in the WGEXT.
The objective of the WGEXT is to provide a summary of data on marine sediment extraction, marine resource and habitat mapping, changes to the legal regime, and research projects relevant to the assessment of environmental effects.
The data on marine sediment extraction is reported to OSPAR on a yearly basis.The data on amounts and areas of marine extraction are given for the ICES countries, both in an overview as well in detail. In 2018, a total of 73.2 million m³ was extracted in these countries.
This report includes extensive reviews on the relation between marine sediment extraction and the Marine Strategy Framework Directive, Cumulative Assessments, and the definition and cal-culation of intensity of dredging to define a footprint. An overview of the regulation of the im-pact of extraction on fish and fisheries in different ICES countries is available in the report.
Published under the auspices of the following ICES Steering Group or Committee