Description of biotope or habitat type
To understand more about what this page is describing, see How to use the classification. See also How to cite.
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 |
| Tidal streams | |
| Substratum | Boulders; Pebbles and cobbles on sand/mud |
| Zone | Eulittoral |
| Depth Band | |
| 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.
Description
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 Austrominius 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 Ulva 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.
Situation
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).
Temporal variation
Some variation in the ephemeral seaweeds and their abundance depending on the season is likely.
Characterising species
| Taxon | Relative importance of taxon for defining this community (%) | Typical abundance - SACFOR scale | % of core records where taxon was recorded |
|---|---|---|---|
| Fucus vesiculosus | 46 | Common | 81-100% |
| Semibalanus balanoides | 10 | Frequent | 41-60% |
| Ulva intestinaloides | 8 | Frequent | 41-60% |
| Littorina littorea | 7 | Occasional | 41-60% |
| Carcinus maenas | 6 | Occasional | 41-60% |
| Ascophyllum nodosum | 3 | Occasional | 21-40% |
| Austrominius modestus | 3 | Frequent | 21-40% |
| Mytilus edulis | 3 | Occasional | 41-60% |
| Gammaridae | 2 | Frequent | 21-40% |
| Littorina saxatilis | 2 | Frequent | 21-40% |
Similar biotopes or habitat types
LR.LLR.F.Fves.FS
Occurs in marine conditions, but otherwise a similar habitat. Higher species richness and the F. vesiculosus canopy is more dense due to less siltation. The limpet Patella vulgata is present.
LR.LLR.F.Fves.X
Occur on similar substrata, but in fully marine conditions. Similar species composition though higher species richness. P. vulgata and L. saxatilis.
LR.FLR.Eph.BLitX
Occur on more unstable substrata, which do not allow F. vesiculosus (Occasional) to become established in any high abundance.Classification history of this biotope or habitat type
| Classification version | Code |
|---|---|
| 1997 (97.06) | SLR.Fves (part) |