Biotope - Typologie Européenne EUNIS

A5.52 - Niveau 4 : Biocénoses à laminaires et algues sur sédiment subtidal
Description
Shallow sublittoral sediments which support seaweed communities, typically including the kelp Laminaria saccharina, the bootlace weed Chorda filum and various red and brown seaweeds, particularly filamentous types. The generally sheltered nature of these habitats enables the seaweeds to grow on shells and small stones which lie on the sediment surface; some communities develop as loose-lying mats on the sediment surface.
Taxons (Liens actifs si espèces présentes)
Bonnemaisonia asparagoides (Woodward) C.Agardh, 1822, Brongniartella byssoides (Goodenough & Woodward) F.Schmitz, 1893, Corallinaceae Lamouroux, 1812, Delesseria sanguinea (Hudson) J.V.Lamour., 1813, Gracilaria gracilis (Stackh.) M.Steentoft, L.M.Irvine & W.F.Farnham, 1995, Halarachnion ligulatum (Woodward) Kütz., 1843, Lomentaria clavellosa (Lightf. ex Turner) Gaillon, 1828, Nematoda sp., Nemertea sp., Phycodrys rubens (L.) Batters, 1902, Phyllophora crispa (Hudson) P.S.Dixon, 1964, Plocamium cartilagineum (L.) P.S.Dixon, 1967, Polyides rotunda (Hudson) Gaillon, 1828, Polysiphonia elongata (Hudson) Sprengel, 1827, Pterothamnion plumula (J.Ellis) Nägeli, 1855, Rhodophyllis divaricata (Stackh.) Papenf., 1950, Terebellidae sp., Trailliella intricata Batters, 1896, Ulva L., 1753,
A5.522 - Niveau 5 : Saccharina latissima (anciennement Laminaria saccharina) et Chorda filum sur sédiment vaseux abrité de l'infralittoral supérieur
Description
Shallow kelp community found on sandy mud and gravelly sandy mud, in sheltered or extremely sheltered conditions, with very weak tidal currents. The community is characterised by a reasonable covering of Laminaria saccharina and Chorda filum. Beneath the kelp canopy, Ulva lactuca is often frequent and some filamentous and foliose red algae may be present, along with filamentous brown ectocarpoid algae although in much lower abundance than in the A5.521 subunits. At the sediment surface ubiquitous fauna such as Asterias rubens, crabs such as Pagurus bernhardus, Carcinus maenas, and the gastropod Gibbula cineraria may be visable and in some areas Sabella pavonina may be present. Given the nature of the sediment it is likely that a wide range of infaunal bivalves and polychaetes are present including Arenicola marina, Mediomastus fragilis and Anaitides mucosa. In more tideswept areas with coarser and generally less muddy sediments A5.522 may be replaced by one of the sub units of A5.521.
Taxons (Liens actifs si espèces présentes)
Enteromorpha Link, 1820 ( Esp. caract. )
Polyides rotunda (Hudson) Gaillon, 1828 ( Esp. caract. )
Ulva L., 1753 ( Esp. caract. )
Analyse Ecologie du milieu (En fonction des espèces présentes)