⌘K
Biotope - Typologie Européenne EUNIS
A3.32 - Niveau 4 : Laminaires sur roche infralittorale sous faible hydrodynamisme en milieu à salinité variable
Description
Very wave-sheltered bedrock, boulders and cobbles subject to only weak tidal streams in the sublittoral fringe and infralittoral zone, in areas of variable/reduced salinity. This habitat type is characterised by the kelp Laminaria saccharina and coralline crusts such as Lithothamnion glaciale. Grazers such as the urchins Psammechinus miliaris and Echinus esculentus, and the gastropods Gibbula cineraria and Buccinum undatum may be present. The tube-dwelling polychaete Pomatoceros triqueter, the ascidians Ciona intestinalis, Corella parallelogramma and Ascidiella scabra, the barnacle Balanus crenatus, the starfish Asterias rubens and the brittlestar Ophiothrix fragilis may also be present. Red algal communities are composed primarily of Phycodrys rubens. The crabs Carcinus maenas and Pagurus bernhardus, and the bivalve Modiolus modiolus may also be observed.
Taxons (Liens actifs si espèces présentes)
A3.323 - Niveau 5 : Saccharina latissima (anciennement Laminaria saccharina) avec Phyllophora spp. et algues vertes filamenteuses sur roche infralittorale en milieu à salinité variable ou réduite
Description
Shallow infralittoral bedrock or boulder slopes, in reduced or low salinity conditions, characterised by the kelp Laminaria saccharina with dense stands of silted filamentous green seaweeds and red seaweeds Phyllophora crispa, Phyllophora pseudoceranoides and Phycodrys rubens. The filamentous green seaweeds e.g. Chaetomorpha melagonium and Cladophora spp. can form a blanket cover amongst the L. saccharina in the upper zone, which is under greater influence of freshwater input. In deeper water the green seaweeds are replaced by red seaweed Phyllophora spp. or Polysiphonia fucoides which may form a distinct sub-zone in the biotope. Coralline crust can be present. The solitary ascidians Corella parallelogramma and Ascidiella scabra are often epiphytic on the seaweed (particularly Phyllophora spp.) and dominate the animal community along with the starfish Asterias rubens. The small ascidian Dendrodoa grossularia, the barnacle Balanus crenatus and the tube-building polychaete Pomatoceros triqueter occur on the rock surface. More mobile species include the crab Carcinus maenas, the hermit crab Pagurus bernhardus and the whelk Buccinum undatum. Bryozoans Electra pilosa and Spirorbis sp. may cover kelp fronds. The red seaweed Odonthalia dentata may be present in the north.
Situation: The ascidians found in this unit may continue onto the circalittoral rock below where dense colonies of anthozoans and brachiopods can also be found (A4.3142). Where tidal streams are increased, sponge and hydroid communities may occur below (A4.252).
Taxons (Liens actifs si espèces présentes)
Corallinaceae Lamouroux, 1812 ( Esp. caract. )
Odonthalia dentata (L.) Lyngybe, 1819 ( Esp. caract. )
Phycodrys rubens (L.) Batters, 1902 ( Esp. caract. )
Phyllophora crispa (Hudson) P.S.Dixon, 1964 ( Esp. caract. )
Phyllophora pseudoceranoides (S.G.Gmelin) Newroth & A.R.A.Taylor, 1971 ( Esp. caract. )
Polysiphonia fucoides (Hudson) Grev., 1824 ( Esp. caract. )
Odonthalia dentata (L.) Lyngybe, 1819 ( Esp. caract. )
Phycodrys rubens (L.) Batters, 1902 ( Esp. caract. )
Phyllophora crispa (Hudson) P.S.Dixon, 1964 ( Esp. caract. )
Phyllophora pseudoceranoides (S.G.Gmelin) Newroth & A.R.A.Taylor, 1971 ( Esp. caract. )
Polysiphonia fucoides (Hudson) Grev., 1824 ( Esp. caract. )
Analyse Ecologie du milieu (En fonction des espèces présentes)