Species list for Dutch North Sea available to view now

Published on
June 13, 2017

The Netherlands has almost 1300 multicellular species in the North Sea, of which approximately 6% are exotics. This has been established by researchers from Wageningen Marine Research, GiMaRIS and Naturalis Biodiversity Center. The new species list is available in digital format from today.

The list of species was drawn up at the request of the Ministry of Economic Affairs. It will enable the government to promote the conservation and sustainable use of the natural biodiversity, to develop policy such as ‘Bouwen met Noordzeenatuur’ ('Building with North Sea Nature') in order to enhance the ecological value of North Sea offshore wind farms, for example, and to track exotic species in the North Sea.

We have not previously had such a complete list of life in the Dutch North Sea
Oscar Bos, Wageningen Marine Research

Numbers of North Sea species

The total number of salt and brackish water species in Dutch waters (North Sea, Wadden Sea, Zeeland Delta) is over 1909, of which 8% are exotics. 1284 of these species occur in the Dutch North Sea, of which 6% are exotics. Of the North Sea species, some 622 live in the shallower North Sea coastal zone (0-20 m depth) and 847 in the deeper parts. Of the bottom-dwelling organisms in the North Sea, 812 occur on sand floors and silt floors (soft substrate) and 524 on hard surfaces such as stone, dykes and shipwrecks and platforms (hard substrate).

"Never before have we had such a complete list of life in the Dutch North Sea" says researcher Oscar Bos, who helped compile the list of species at Wageningen Marine Research. "This is a handy checklist for researchers, but also for divers and beach walkers, to see whether an observation is indeed unique. And if you want to know which exotic species there are in the North Sea, it is now a matter of pressing a button. The list is accompanied by lots of beautiful photos. These are of interest to everyone. Many people have no idea about all the life there is in the sea and how colourful it is under water."


The biggest group of species represented are the arthropods (crabs, lobsters, shrimps and other groups), with 301 species in the North Sea. Other important groups are the chordates (fish, mammals, birds and sea squirts), ring worms, molluscs (shellfish, nudibranchs and squid) and coelenterates (anemones and jellyfish). The World Register of Marine Species (WoRMS) ) lists approximately 214,000 marine species worldwide. The new species list reveals that the North Sea accounts for 0.6% of global biodiversity.

The marine and brackish water species (1909 species) contribute about 5% of total Dutch species diversity on land and in the water (approximately 36,000 species). This percentage seems low, given that the North Sea and other saltwater areas together make up no less than 62% of the total area of the Netherlands. This relatively low biodiversity is explained by the smaller diversity of habitats in the sea (primarily sandy floors) and the virtual absence of insects and fungi in the sea, groups which account for a large number of different species. At a higher taxonomic level, the biodiversity of the sea is in fact greater than that on land: groups such as echinoderms, sea squirts, coelenterates, sponges and sipuncula exclusively occur in water.


New species

The species list was compiled from databases and publications which had not previously been combined. It is notable that new species are still being discovered in the North Sea, such as the Doto pinnatifida on a shipwreck and a number of bryozoans on fishing nets recovered from shipwrecks. These are primarily species which are not identified during the regular seafloor monitoring, but which are observed in surveys by, for example, Duik de Noordzee Schoon (a foundation for divers dedicated to cleaning the North Sea) and the Anemoon foundation (beachcombers), as well as during research on oil and gas platforms and offshore wind farms.

Since the completion of the data collection for the report, a further 20-25 species have been discovered which are new to the North Sea. These species were discovered during a recent sampling of the Klaverbank, an area with a hard substrate in the Western part of the North Sea. A number of entoprocta have also been discovered and a bryozoan was found on an offshore gas production platform in the middle of the Dutch North Sea. These species will be included when the list is updated.

Digital species list

The species list is also available in digital format as part of the Dutch Species Register. In the digital species list, the salt water and brackish water species are broken down according to the standard taxonomy. An indication is given as to whether the species occurs naturally or is exotic. For the exotics, more information is available on the website via the 'exotics passport'. Information can also be found about the salt and brackish water areas in which the species occur. For the bottom-dwelling organisms, an indication is given as to whether they live on hard or soft substrates. This list is kept up to date.

The digital Dutch North Sea species list is available to view on the website of the Dutch Species Register of Naturalis Biodiversity Center.

The digital Dutch North Sea species list is available to view on the website of the Dutch Species Register of Naturalis Biodiversity Center.

More information about the species list

More information about marine species may be found in the report (PDF) by Wageningen Marine Research 'Species List for the Dutch North Sea' (Report C126/16A).