In implementation of the Habitats Directive, the habitats directive areas "Trapegeer-Stoombank" and "Vlakte van de Raan" were established in the Belgian part of the North Sea in 2004. At the request of the European Commission to also select areas in the European Economic Zone (EEZ), the area "Trapegeer-Stroombank" was designated as the habitats directive area "Vlaamse Banken" by the Royal Decree of October 16, 2012.
This habitats directive area "Vlaamse Banken" was selected on the basis of a scientific evaluation of potential habitats directive areas in the Belgian part of the North Sea. The area "Vlakte van de Raan" was cancelled by a decision of the Council of State in 2008.
The habitats directive area "Vlaamse Banken" is a 1099.39 km2 size habitats directive area and is located in the southwestern part of the Belgian North Sea. It borders the French Birds and Habitats area "Bancs de Flandres" and extends to about 45 km into the sea. It thus includes a part of the territorial waters as well as a part of the EEZ. The former habitats directive area “Trapegeer-Stroombank” constitutes a part of this.
The “Vlaamse Banken” are designated for the protection of the "sandbanks permanently covered with seawater" (Habitat type code 1110) and the "Reefs" (Habitat type code 1170). These sandbanks and reefs are ecologically the most valuable habitats of our North Sea.
• The sandbanks are characterised by four macrobenthic communities; communities of animal species living on or in the seabed. Each of these communities are characterised by the species with its own diversity and density that are typical to certain types of seabed. These communities do not occur isolated from each other; gradual transitions between the communities are extensively found in our North Sea.
- The Macoma baltica community with a low diversity of species, but with a rather high density (average of 967 individuals/m²) of silty sediments;
- the Abra alba (or Mysella bidentata) community with a high density (average of 6432 individuals/m²) and a high diversity of species from silt to fine sand;
- the Nephtys cirrosa community with a low density (average of 402 individuals/m²) and a low diversity of species from fine to medium sandy sediments;
- the Ophelia limacina (orGlycera lapidum) community with a very low density (average of 190 individuals/m²) and a diversity of species of medium-to coarse sandy soils.
• The two biotopes that can be characterised as "reefs" occur separated in our North Sea:
- the reefs formed by the sand mason worms (Lanice conchilega) are located in shallow water closer to the coast. These aggregations constitute a part of the macrobenthic community of Abra alba. By clumping together, these sand worms form their own micro-habitat which in turn becomes attractive to other species. The sand mason worms are also therefore called "habitat engineers" that locally support a highly enhanced biodiversity.
- the gravel beds occur deeper in the sea, especially and to a large extent at the level of the Hinderbanken. The gravel beds likewise constitute a species-rich biotope with a rich fauna and flora. These gravel beds once constituted the biotope of the European oyster which along with the stones were heavily colonised by a very peculiar fauna. Gravel beds fulfill an important function as spawning chamber and nursery of the fish species.
The “Vlaamse Banken” are not selected for the protection of species included in appendix II of the Habitats Directive, because the populations of these species in the Belgian maritime regions are of minor importance and because no core areas that may be of interest particularly for these species and for a longer period can be designated. Nevertheless, some of these species are observed in the “Vlaamse Banken”; in the first place, the common seal and the harbour porpoise that can occur in internationally significant numbers (up to 2% of the North Sea population) in the Belgian North Sea. Besides, the grey seal too occurs. The European river lamprey, the twait shad and the European sea sturgeon occur rarely or very rarely.