MB1-218 - Laminaria hyperborea sur roche soumise aux courants des marées de l'infralittoral en Atlantique

Laminaria hyperborea on tide-swept Atlantic infralittoral rock

Classification des habitats EUNIS 2022

Descriptif de l'habitat

Wave exposed to moderately wave exposed, tide-swept bedrock and boulders with Laminaria hyperborea, characterised by a rich under-storey and stipe flora of foliose seaweeds including the brown seaweed Dictyota dichotoma. The kelp stipes support epiphytes such as Cryptopleura ramosa and Phycodrys rubens. At some sites, instead of being covered by red seaweeds, the kelp stipes are heavily encrusted by the ascidian Botryllus schlosseri. Epilithic seaweeds Delesseria sanguinea, Plocamium cartilagineum Heterosiphonia plumosa, Hypoglossum hypoglossoides, Callophyllis laciniata, Kallymenia reniformis, Brongniartella byssoides and crustose seaweeds commonly occur beneath the kelp. The kelp fronds are often covered with growth of the hydroid Obelia geniculata or the bryozoan Membranipora membranacea. On the rock surface, a rich fauna comprising the bryozoan Electra pilosa, the sponge Pachymatisma johnstonia, anthozoans such as Alcyonium digitatum, Sagartia elegans and Urticina felina, colonial ascidians such as Clavelina lepadiformis, the calcareous tubeworm Pomatoceros triqueter and the barnacle Balanus crenatus occur. More mobile species include the gastropod Calliostoma zizyphinum, the crab Cancer pagurus and the echinoderms Asterias rubens and Echinus esculentus. Two variants have been described: Tide-swept kelp forest (unit MB1-2181) and tide-swept kelp park (unit MB1-2182).
Situation: This biotope occurs below Alaria esculenta at exposed sites or L. digitata at moderately exposed locations. With increasing depth the kelp density diminishes to become tide-swept kelp park (MB1-2182).

Bibliography

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