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Concept: [Phymatolithon calcareum] maerl beds in infralittoral clean gravel or coarse sand in the eunishabitats vocabulary

Concept URI http://eunis.eea.europa.eu/eunishabitats/A5.511
Preferred label [Phymatolithon calcareum] maerl beds in infralittoral clean gravel or coarse sand
Definition Maerl beds characterised by [Phymatolithon calcareum] in gravels and sands. Associated epiphytes may include red algae such as [Dictyota dichotoma, Halarachnion ligulatum], [Callophyllis laciniata], [Cryptopleura ramosa], [Brongniartella byssoides] and [Plocamium cartilagineum]. Algal species may be anchored to the maerl or to dead bivalve shells amongst the maerl. Polychaetes, such as [Chaetopterus variopedatus], [Lanice conchilega], [Kefersteinia cirrata], [Mediomastus fragilis, Chone duneri, Parametaphoxus fultoni] and [Grania] may be present. Gastropods such as [Gibbula cineraria], [Gibbula magus], [Calyptraea chinensis] [Dikoleps pusilla] and [Onoba aculeus] may also be present. [Liocarcinus depurator] and [Liocarcinus corrugatus] are often present, although they may be under-recorded; it would seem likely that robust infaunal bivalves such as [Circomphalus casina], [Mya truncata], [Dosinia exoleta] and other venerid bivalves are more widespread than available data currently suggests. It seems likely that stable wave-sheltered maerl beds with low currents may be separable from SMP.Pcal; having a generally thinner layer of maerl overlying a sandy /muddy substratum with a diverse cover of epiphytes (e.g. Bosence 1976; Blunden [et al]. 1977; 1981; Davies & Hall-Spencer 1996) but insufficient data currently exists on a national scale. Wave and current-exposed maerl beds, where thicker depths of maerl accumulate, frequently occur as waves and ridge / furrows arrangements (see Bosence 1976; Blunden [et al]. 1977; 1981; Irvine & Chamberlain 1994; Hall-Spencer 1995). At some sites where Pcal occurs, there may be significant patches of maerl gravel containing the rare burrowing anemone [Halcampoides elongatus]; this may be a separate biotope, but insufficient data exists at present. Northern maerl beds in the UK do not appear to contain [L. corallioides] but in south-west England and Ireland [L. corallioides] may occur to some extent in Pcal as well as Lcor, where it dominates.
Notation A5.511
Status Valid
Status Modified 2014-01-31
Accepted Date 2014-01-31
Not Accepted Date
Has broader
Has narrower
Has exact match