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Concept: Mixed kelp and red seaweeds on infralittoral boulders, cobbles and gravel in tidal rapids in the eunishabitats vocabulary

Concept URI http://eunis.eea.europa.eu/eunishabitats/A3.223
Preferred label Mixed kelp and red seaweeds on infralittoral boulders, cobbles and gravel in tidal rapids
Definition Mixed substrata of boulders, cobbles, pebbles and gravel, typically found in tidal rapids with kelp [Laminaria saccharina] and [Laminaria hyperborea] and red seaweeds. [L. saccharina] usually dominates this habitat although [L. hyperborea] may occur in equal abundance at some sites. The kelp in these tidal rapids does not form the same dense canopies associated with stable tide-swept bedrock, but generally occurs at lower abundance (Frequent). Other brown seaweeds occur in significant amounts in these tidal rapids including [Dictyota dichotoma], [Halidrys siliquosa] and [Chorda filum]. These mixed substrata support a greater diversity of species than scoured bedrock narrows (XKT). In particular, there is an increase in red algal species such as [Corallina officinalis, Bonnemaisonia hamifera] and [Ceramium nodulosum], although none occur in any great abundance. Red seaweeds common to both XKT and this biotope include [Chondrus crispus], [Delesseria sanguinea], [Plocamium cartilagineum] and [Phycodrys rubens]. Good examples of this biotope often have maerl gravel ([Lithothamnion] sp.) or rhodoliths between cobbles and boulders. Where maerl dominates, the biotope should be recorded as a maerl bed (SS.SMP.Mrl). The sponges associated with more stable, tide-swept conditions are generally absent, but the anthozoan [Anemonia viridis] might be present. Cobbles and pebbles are encrusted by the ubiquitous polychaete [Pomatoceros triqueter] and provide shelter for scavenging crabs such as [Carcinus maenas] and the hermit crab [Pagurus bernhardus], gastropods such as [Gibbula cineraria] and echinoderms such as [Echinus esculentus, Asterias rubens], [Ophiocomina nigra] and [Ophiothrix fragilis] which favour these sites of increased water movement. Additional infaunal species, inhabiting the sediment pockets, include [Lanice conchilega] and [Sabella pavonina], which can be locally abundant. Situation: Where stable rock fringes the shallows the tide-swept [Laminaria digitata] biotope often occurs (LdigT). Adjacent areas of stable bedrock or boulders in these sheltered, tide-swept narrows can support a similar kelp community, often with a greater percentage of [L. hyperborea] (XKT). Maerl fragments are often found amongst the mixed substrata of XKTX and this biotope may abut more extensive areas of maerl bed (Phy & Lgla).
Notation A3.223
Status Valid
Status Modified 2014-01-31
Accepted Date 2014-01-31
Not Accepted Date
Has broader
Has exact match