MA1-277 - Éponges, bryozoaires et ascidies sur surplombs rocheux importants ou grottes de la partie inférieure du rivage (EUNIS 2022)

MA1-277 - Éponges, bryozoaires et ascidies sur surplombs rocheux importants ou grottes de la partie inférieure du rivage

Sponges, bryozoans and ascidians on deeply overhanging lower shore bedrock or caves

MA1-276 - Éponges et algues rouges tolérantes à l'ombre sur surplombs rocheux du médiolittoral inférieur et en entrée des grottes

MA1-278 - Faune encroûtante sur parois des grottes médiolittorales battues par les vagues

Classification des habitats EUNIS 2022

Descriptif de l'habitat

Overhanging, and shaded vertical, bedrock on the lower shore and in lower shore caves, which is not subject to appreciable wave-surge, characterised by crusts of bryozoans including Umbonula littoralis, sponges such as Grantia compressa, Halichondria panicea, Scypha ciliata and Hymeniacidon perleve and the ascidian Botryllus schlosseri. On overhangs, the hydroid Dynamena pumila hangs in distinct form from overhanging rock. The barnacles Balanus crenatus, Balanus perforatus (sometimes at high densities) and Semibalanus balanoides, and the calcareous tube-forming polychaetes Spirorbis spp. and Pomatoceros triqueter can be present as well. Certain species which are generally confined to the sublittoral, including the anemones Metridium senile and Corynactis viridis, may be found in the lower shore caves and overhangs. Littoral species such as Actinia equina are also present. The only algae present are coralline crusts. The list of characterising species partly reflects the variation in the species composition between individual overhangs and caves although this biotope can have a high species richness.
Situation: This biotope is found in the lower eulittoral and sublittoral fringe in less wave-surged conditions than that of unit MA1-2761.

Bibliographie

European Topic Centre on Biological Diversity 2022. EUNIS marine habitat classification 2022 including crosswalks. Table Excel. (Source)