Search

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 (Fves.FS) and mixed substrata (Fves.X). Please notice that a F. vesioculosus biotope subject to variable salinity (FvesVS) has been identified.

Sheltered and very sheltered mid eulittoral pebbles and cobbles lying on sediment in fully marine conditions typically characterised by the wrack Fucus vesiculosus. The wrack Ascophyllum nodosum can occasionally be found on larger boulders while the barnacle Semibalanus balanoides and the limpet Patella vulgata also can be present on the cobbles with the whelk Nucella lapillus preying on the barnacles and on the mussel Mytilus edulis. Winkles, particularly Littorina littorea and Littorina obtusata, commonly graze the biofilm on the seaweeds, while Littorina saxatilis can be found in crevices. Ephemeral seaweeds such as Ulva intestinalis may be present in this biotope. The sediment between patches of hard substrata often contains the polychaete Arenicola marina or the polychaete Lanice conchilega, while a variety of gastropods and the crab Carcinus maenas occur on and under cobbles.

Moderately exposed to 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, Littorina saxatilis and the whelk Nucella lapillus are found beneath the seaweeds, whilst Littorina graze on the fucoid fronds. The calcareous tube-forming polychaete Spirorbis spirorbis may also occur epiphytically on the fronds. In areas of localised shelter the wrack Ascophyllum nodosum may occur, though never at high abundance. Damp cracks and crevices often contain patches of the red seaweed Mastocarpus stellatus and even the wrack Fucus serratus may be present. The crab Carcinus maenas may be present in pools or among the boulders.