Compiled by: Leigh Jones, Joint Nature Conservation Committee, Monkstone House, City
Road, Peterborough PE1 IJY, UK.
Derived, in part, from: the UK marine biotope classification (Connor et al.
1997b) and a review undertaken for the UK Marine SACs Project (Birkett et al.
|Europe (EUNIS Nov. 1999)
||Phymatolithon calcareum maerl beds in shallow-water
clean gravel and coarse sand
||Maerl beds on shallow-water muddy mixed sediments
|Britain/Ireland (MNCR BioMar 97.06)
|Maerl beds (open coasts/clean sediments)
Maerl beds (muddy
||Fonds à Lithothamnion (= Phymatolithon) calcareum,
IGS.Mrl. Beds of maerl in coarse clean sediments of gravels and clean sands, which
occur either on the open coast or in tide-swept channels of marine inlets (latter often
stony). In fully marine conditions the dominant maerl is typically Phymatolithon
calcareum (IGS.Phy), whilst under variable salinity conditions in some Scottish
sealochs beds of Lithothamnion glaciale (IGS.Lgla) may develop.
IMX.MrlMx. Maerl beds of the genus Lithothamnion or Lithophyllum which
develop on shallow sublittoral muddy gravels. Such sediments are found in marine inlets,
such as rias and sealochs, usually in fully marine or near marine conditions where
significant tidal currents are lacking. Three species of maerl may dominate; L.
corallioides (IMX.Lcor), which is relatively widespread, and Lithophyllum dentatum
and L. fasciculatum (IMX.Lden and IMX.Lfas) which have restricted distributions in
(from MNCR database March 1999)
Species composition and biodiversity
Sensitivity to human activities
Conservation and protection status