Report | January 22, 2020
Protecting the North Sea: New Research for Biodiversity Recovery
Eight nations (Belgium, Denmark, France, Germany, Netherlands, Norway, Sweden, and the United Kingdom) border the North Sea, many of which are densely populated; approximately 184 million people live in its catchment areas.6 As a result, the North Sea has become very industrialised. Its fisheries, oil and gas extraction, shipping, harbours, and wind farms are of high socio‑economic value, and contribute to making it one of the busiest, most highly disturbed seas in the world.7 The International Council for the Exploration of the Sea (ICES) describes the current state of the North Sea ecosystem as “perturbed”.8
Across the North Sea, multiple and overlapping activities compete for resources and space, both at the surface and, less visibly, on the seafloor. The many threats to benthic marine ecosystems in the region include extensive fisheries, maritime shipping, oil and gas exploitation, wind energy development, and the extraction of sand and gravel. In coastal areas, further impacts arise from coastal development, harbours, and recreational activities, among other pressures. In combination, these activities have caused widespread damage to North Sea ecosystems, and few areas of the seabed remain in their natural state.7
The North Sea has historically been – and remains – one of the most important fishing areas in Europe, and is potentially the most heavily fished region in the world.9 More than a century of intensive, industrial fishing pressure has resulted in marked ecosystem changes in its waters. For example, the biomass of large fishes has been reduced by 97‑99%,10 and long-term declines and local extirpations have been documented in large-bodied, vulnerable species such as common skate, thornback ray, and angel shark.11,12
One of the most widespread fishing practices in the North Sea is bottom trawling, which is regarded as the largest anthropogenic source of physical damage to the seafloor globally.13 According to ICES, approximately 43% of the seabed of the Greater North Sea was trawled in 2013,14 which implies extensive damage to benthic habitats and species across the region. The damage generated by the use of these gears ranges from direct physical impacts on the seabed and destruction of biogenic structures, to broadscale changes in the structure and functioning of entire benthic ecosystems.15,16 For example, beam trawling, which is particularly prevalent in the southern North Sea, has been shown to cause dramatic losses in infauna and epifaunal biomass,17 with the greatest impacts on biogenic reefs.18,19 A meta-analysis based on 18 separate studies found that an average of 23 species were lost from a system as a result of beam trawling.2
A high resolution version of this report can be found here.
