Description of biotope or habitat type
Fucus vesiculosus on mid eulittoral mixed substrata
Habitat (physical) description
|Salinity||Full (30-35 ppt), Variable (18-35 ppt)|
|Wave exposure||Moderately exposed, Sheltered, Very sheltered|
|Tidal streams||Moderately strong (1-3 kn), Weak (>1 kn), Very weak (negligible)|
|Substratum||Pebbles and cobbles on sand/mud|
|Other Features||Silt and/or variable salinity|
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 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 Enteromorpha 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.
Fves.X can be found below the biotope dominated by the wrack Fucus spiralis (Fspi.X) or a community dominated by S. balanoides, P. vulgata and L. littorea (BLitX). It is found above a community dominated by M. edulis beds (Myt.Myt) or the wrack Fucus serratus (Fserr.X).
Some variation in the ephemeral seaweeds and their abundance depending on season is likely.
|Taxon||Relative importance of taxon for defining this community (%)||Typical abundance - SACFOR scale||% of core records where taxon was recorded|
|Semibalanus balanoides||7||Frequent||41-60 %|
|Carcinus maenas||3||Occasional||21-40 %|
|Littorina obtusata/mariae||1||Frequent||21-40 %|
|Patella vulgata||5||Frequent||41-60 %|
|Littorina littorea||3||Frequent||81-100 %|
|Littorina saxatilis||18||Frequent||21-40 %|
|Nucella lapillus||5||Occasional||41-60 %|
|Mytilus edulis||3||Occasional||41-60 %|
|Ascophyllum nodosum||3||Occasional||21-40 %|
|Fucus vesiculosus||36||Common||81-100 %|
|Enteromorpha intestinalis||4||Occasional||41-60 %|