Fucus vesiculosus on moderately exposed to sheltered mid eulittoral rock
|EUNIS habitat type||code MA123D|
|Relation to||Resolution 4 habitat type (used for designation of Emerald sites)|
Moderately exposed to very sheltered mid eulittoral bedrock and large boulders characterised by a dense canopy of the wrack Fucus vesiculosus (Abundant to Superabundant). Beneath the seaweed canopy the rock surface has a sparse covering of the barnacle Semibalanus balanoides and the limpet Patella vulgata. The mussel Mytilus edulis is confined to pits and crevices. A variety of winkles including Littorina littorea and Littorina saxatilis can be found grazing on the fucoid fronds. The whelk Nucella lapillus is found beneath the seaweed canopy. In areas of localised shelter the wrack Ascophyllum nodosum may occur, though never at high abundance. The crab Carcinus maenas may be present in pools or among the boulders. Two variants have been described: Bedrock and large boulders (unit MA1-23D1) and mixed substrata (unit MA1-23D2). Please notice that a F. vesioculosus biotope subject to variable salinity (unit MA1-253) has been identified.
Situation: This biotope usually occurs between the wrack Fucus spiralis (MA1-23C) and the Fucus serratus (MA1-23F) zones; both of these fucoids may be present in this biotope, though never at high abundance (typically less than Frequent). In some sheltered areas F. vesiculosus forms a narrow zone above the A. nodosum zone (MA1-23E). Where freshwater runoff occurs on more gradually sloping shores F. vesiculosus may be replaced by the wrack Fucus ceranoides (MA1-257).
Temporal variation: On some shores, particularly those which are moderately exposed to wave action, temporal fluctuations in the abundance of limpets, barnacles and fucoid seaweeds may occur. As a result, over a number of years, a single shore may cycle between the barnacle- P. vulgata dominated biotope (MA1-2232), through this mosaic (MA1-243) to a F. vesiculosus -dominated biotope (MA1-23D).
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)||A1.313||Fucus vesiculosus on moderately exposed to sheltered mid eulittoral rock||same|
|Classification||Code||Habitat type name||Relationship type||Comment|
|EUNIS Habitat Classification 200410||A1.313||Fucus vesiculosus on moderately exposed to sheltered mid eulittoral rock||same|
|EUNIS Habitat Classification 200308||A1.313||Fucus vesiculosus on sheltered mid eulittoral rock||wider|
|EUNIS Habitat Classification 200202||A1.313||Fucus vesiculosus on sheltered mid eulittoral rock||same|
|EUNIS Habitat Classification 199910||A1.313||Fucus vesiculosus on sheltered mid eulittoral rock||same|
|MNCR BioMar 97.06 (Britain & Ireland)||SLR.F.Fves||Fucus vesiculosus on sheltered mid eulittoral rock||same|