Ascophyllum nodosum on very sheltered mid eulittoral rock
|EUNIS habitat type||code MA123E|
|Relation to||Resolution 4 habitat type (used for designation of Emerald sites)|
Sheltered to extremely sheltered mid eulittoral rock with the wrack Ascophyllum nodosum. The red seaweed Polysiphonia lanosa is often found growing as an epiphyte on the A. nodosum fronds while disturbed areas among the A. nodosum is colonised by the wrack Fucus vesiculosus and the green seaweed Enteromorpha intestinalis.e barnacle Semibalanus balanoides, the limpet Patella vulgata and Littorina littorea can all be found on the bedrock underneath the A. nodosum canopy along with coralline crusts. The whelk Nucella lapillus can be found preying on the barnacles and limpets. Three variants of this biotope are described. These are: full salinity (unit MA1-23E1), mixed substrata (unit MA1-23E2) and the loose lying growth form A. nodosum ecad mackaii found on very sheltered shores (MA1-255). Two other biotopes has been identified as well tide-swept (MA1-238) and variable salinity (MA1-254).
Situation: This biotope is usually found between the wrack Fucus spiralis (MA1-23C) and F. serratus dominated biotopes (MA1-23F), although on some shores a narrow zone of F. vesiculosus (MA1-23D) may occur immediately above the A. nodosum. With increasing wave exposure the A. nodosum canopy is replaced by F. vesiculosus (MA1-243; MA1-23D). Unit MA1-23E can occur on more exposed shores, where there is localised shelter.
Temporal variation: A. nodosum communities are generally very stable communities with individual plants reaching ages of more than 25 years on shores with little wave-action.
Source: EUNIS habitat classification
Relation to other habitat types mentioned in legal instruments
Relation to vegetation types (syntaxa)Not available
Species mentioned in habitat description
|Species scientific name||English common name||Species group|
|Nucella lapillus||Dog whelk||Invertebrates|
|Classification||Code||Habitat type name||Relationship type|
|EUNIS Habitat Classification 2007 (revised descriptions 2012)||A1.314||Ascophyllum nodosum on very sheltered mid eulittoral rock||same|
|Classification||Code||Habitat type name||Relationship type||Comment|
|EUNIS Habitat Classification 200410||A1.314||Ascophyllum nodosum on very sheltered mid eulittoral rock||same|
|EUNIS Habitat Classification 200308||A1.314||Ascophyllum nodosum on very sheltered mid eulittoral rock||same|
|EUNIS Habitat Classification 200202||A1.314||Ascophyllum nodosum on very sheltered mid eulittoral rock||same|
|EUNIS Habitat Classification 199910||A1.314||Ascophyllum nodosum on very sheltered mid eulittoral rock||same|
|MNCR BioMar 97.06 (Britain & Ireland)||SLR.F.Asc||Ascophyllum nodosum on very sheltered mid eulittoral rock||same|