Hotspot for Biodiversity in the North Sea Rediscovered

Biodiversity hotspot in the sea (picture A.Norro RBINS).
16/07/2015
Hotspot for Biodiversity in the North Sea Rediscovered
post by
Sigrid Maebe

Belgian biologists have rediscovered a hotspot for underwater life in the North Sea. In the vicinity of a few sandbanks along the Belgian coast, the fauna is flourishing just like it was a hundred years ago. Despite increased disruption due to fishing, the area is teeming with whelks, top shells and dead man’s fingers.

The Belgian North Sea primarily has a sandy bed, but on the edges of some sandbanks there are gravel beds made up of rocks and pebbles. More than a hundred years ago Professor Gustave Gilson, a Belgian pioneer in biological marine research, ascertained that the biodiversity there was very high, differing greatly from the surrounding sandy areas. The gravel beds were also breeding grounds for fish, including herring, which found shelter there.

Over subsequent decades, the gravel areas were greatly diminished due to fishing: the stones were overturned or pulled up along with the catch, which meant the species that were typical of the region could no longer live there. But ten years ago a remnant of this gravel fauna was found around the Hinderbanken, the sandbanks along the Belgian coast, and the area is still prospering today, as can be seen from new sampling taken by biologists from the Royal Belgian Institute for Natural Sciences.

Typical species

The Flemish research ship, Simon Stevin, once again set sail in order to investigate the gravel beds. While the aquatic communities in the gravel beds around the biodiversity hotspot show clear signs of disturbance and are depleted, typical species are still present, including whelks, top shells, spider crabs and long-legged spider crabs, sea beards and dead man’s fingers. A number of vulnerable species, such as the European flat oyster which once formed reefs there, seem to have disappeared.

The discovery of this residual community confirms the potential for the gravel beds in our Belgian waters to recover. ‘All soil disturbance should be banned’, say marine biologists Ilse De Mesel and Francis Kerckhof. ‘The Marine Spatial Plan prohibits activities which churn up the seabed in specific places. So there should be some improvement! Species that have disappeared would be able to return and in time even oyster beds may reappear.’

Click on the photo for more pictures.

Subscribe to Royal belgian Institute for natural Sciences News
Go to top