The report focuses on the field of marine sediment extraction, the removal of sand, gravel, minerals, and other sediments from the sea bed for such uses as construction and beach nourishment. This activity has shown a spectacular recent increase in the North Atlantic, including in the Baltic and North seas, with extraction rising from a few hundred thousand cubic metres annually in the early 1970s, to millions in the 1990s, and hundreds of millions in recent years.
In a strict sense, the extraction of marine sediments is not sustainable, because the extracted sediments are lost for the marine system. Taking out these sediments can even have negative effects on the surrounding environment through the removal of seabed organisms, the introduction of a sand blanket in the vicinity, the introduction of high concentrations of suspended matter in the nearby area, and an increase in the level of underwater sound.
Nevertheless, extraction can be sustainable in the sense that the effects on the ecosystem are minimized by mitigation measures beneficial for the recolonization of benthic fauna, ensuring recovery is fulfilled in acceptable time after the extraction.
To ensure mitigation goals are reached, extensive monitoring programmes are carried out in areas such as suspended matter, recolonization, underwater sound, and on effects on other use of the sea and coastal defence.
The CRR was compiled by members of ICES Working Group on the Effects of Extraction of Marine Sediments on the Marine Ecosystem (WGEXT), which develops the understanding to ensure that extraction is managed in a sustainable manner and that any ecosystem effects are understood in order to adopt appropriate mitigative measures.
The report provides an overview on the developments and results of the aforementioned themes across ICES Member Countries between 2005 and 2011.