Habitat type H1110B op de Vlakte van de Raan
Nationally, the definition of the habitat type ‘sandbanks which are slightly covered by sea water all the time, subtype North Sea Coastal Zone’ is based on various forms of the earth’s surface and tidal flow. It includes sandbanks that are constantly under water in shallow parts of the sea where the height of the water column rarely exceeds 20 m. In places there may be a hard substrate such as a shell bed, peat, boulder clay or cobbles, or structures formed by organisms. This habitat type is taken to include the entire complex of sandbanks, the depressions and channels between them (which may be deeper than 20 m), any hard structures and the water column above all this.
In clear water, photosynthesis can occur at this depth of 20 m, but in the predominately turbid or cloudy coastal area light does not penetrate to this depth. Consequently, algae communities can occur only in the shallower areas of this habitat type. In the past, coverings of marine eelgrass (Zostera marina) were also present in these areas
Within Europe, this habitat type is of great importance. Relatively speaking, the Dutch coast and the Dutch Continental Shelf contribute greatly to the acreage of this habitat type within the European Union. While the sandbanks of this habitat type can be found at many sites along the coasts of Europe, this combination of abiotic and biotic qualities is not common at sites otherwise similar to the Voordelta and the Wadden Sea. Among other places, this combination occurs in the Danish and German Wadden Sea and in the Wash, the Norfolk estuary on Britain’s eastern coast.
Subtype A does not occur in the North Sea; it occurs exclusively in the Wadden Sea.
Subtype B occurs at the Voordelta, North Sea Coastal Zone 1 and Westerschelde sites, which have already been designated. In addition, this habitat type occurs at the already notified but not yet designated sites of North Sea Coastal Zone 2 and Vlakte van de Raan.
Habitat subtypes H1110A and B are described in the profile document H1110 (pdf: 15 pages).
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