Description of biotope or habitat type
Fucus vesiculosus on variable salinity mid eulittoral boulders and stable mixed substrata
Physical habitat description
|Salinity||Variable (18-35 ppt)|
|Wave exposure||Sheltered, Very sheltered, Extremely sheltered|
|Substratum||Boulders; Pebbles and cobbles on sand/mud|
|Other Features||Variable salinity and/or silt|
Download comparative physical and biological data. The comparative tables enable a rapid comparison of the species composition and principal physical characteristics between a given set of biotopes.
- Records used to define the biotope (core records)
- Other records assigned to this biotope, marked as 'certain'
- Other records assigned to this biotope, marked as 'uncertain'
Point data based on records in the UK Marine Recorder Snapshot.
Sheltered to extremely sheltered mid eulittoral pebbles and cobbles lying on sediment subject to variable salinity and characterised by the wrack Fucus vesiculosus. The wrack Ascophyllum nodosum can occasionally be found on larger boulders, while the barnacles Semibalanus balanoides and Elminius modestus and the mussel Mytilus edulis can be present on cobbles. Winkles, particularly Littorina littorea, commonly graze on the seaweeds, while Littorina saxatilis can be found in crevices. Ephemeral seaweeds such as Enteromorpha intestinalis can occupy available space. Patches of sediment found between the hard substrata often contains the lugworm Arenicola marina or the sand mason Lanice conchilega, while the crab Carcinus maenas, gammarids and amphipods occur on and under cobbles.
Fves.VS can be found below the biotope dominated by the wracks Fucus spiralis or Fucus ceranoides (Fspi.X; Fcer) or a community dominated by S. balanoides, P. vulgata and L. littorea (BLitX). It is found above a community dominated by M. edulis (Myt.Myt) or the wrack Fucus serratus (Fserr.VS).
Some variation in the ephemeral seaweeds and their abundance depending on the season is likely.
|Taxon||Relative importance of taxon for defining this community (%)||Typical abundance - SACFOR scale||% of core records where taxon was recorded|
|Elminius modestus||3||Frequent||21-40 %|
|Semibalanus balanoides||10||Frequent||41-60 %|
|Carcinus maenas||6||Occasional||41-60 %|
|Littorina littorea||7||Occasional||41-60 %|
|Littorina saxatilis||2||Frequent||21-40 %|
|Mytilus edulis||3||Occasional||41-60 %|
|Ascophyllum nodosum||3||Occasional||21-40 %|
|Fucus vesiculosus||46||Common||81-100 %|
|Enteromorpha intestinaloides||8||Frequent||41-60 %|
Similar biotopes or habitat types
Classification history of this biotope or habitat type
|97.06||SLR.Fves in part|