Ecosystem overviews

Greater North Sea Ecoregion

Trends in non-indigeous species
​​​​​​​​​​​​​​​​​​​​​This ecoregion has 274 non-indigenous (NIS) and cryptogenic (obscure or of unknown origin) species. The majority (142 species) arrived between 1950 and 1999, with 60 species arriving since the beginning of the 21st century. Since 2000, a total of 21 new species have been recorded, all of which are new to Europe. The discovery rate increased between 1950–1999 and 2000–2014.

The main vector for primary introductions is vessels, either through ballast water or hull fouling, followed by aquaculture. Natural spread from neighbouring countries is considered to account for a third of the introduced species.

The observed ecological impacts include significant reductions in the abundance of several important native species and changes to the physical and chemical composition of both sediments and the water column. Additional impacts include: out-competing native commercial species, fouling of aquaculture and fishing gear, and fish kills through toxin production. However, some NIS are considered as valuable resources.
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​Annual rate of new non-indigenous and cryptogenic species discoveries in the Greater North Sea 1950–1999 and 2000–2014. Click image to enlarge.

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Greater North Sea Ecoregion

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