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 mid eulittoral mixed substrata
Physical habitat 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 |
| Zone | Eulittoral |
| Depth Band | |
| 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.
Description
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.
Situation
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).
Temporal variation
Some variation in the ephemeral seaweeds and their abundance depending on 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 | 36 | Common | 81-100% |
| Littorina saxatilis | 18 | Frequent | 21-40% |
| Semibalanus balanoides | 7 | Frequent | 41-60% |
| Patella vulgata | 5 | Frequent | 41-60% |
| Nucella lapillus | 5 | Occasional | 41-60% |
| Ulva intestinalis | 4 | Occasional | 41-60% |
| Ascophyllum nodosum | 3 | Occasional | 21-40% |
| Carcinus maenas | 3 | Occasional | 21-40% |
| Littorina littorea | 3 | Frequent | 81-100% |
| Mytilus edulis | 3 | Occasional | 41-60% |
| Littorina | 1 | Frequent | 21-40% |
Similar biotopes or habitat types
LR.LLR.F.Fves.FS
Occurs on bedrock, but otherwise similar physical conditions. Similar species composition, but the F. vesiculosus canopy is more dense due to more stable substrata.
LR.LLR.FVS.FvesVS
Occurs on similar substrata, but in variable salinity conditions. Similar species composition though lower species richness. P. vulgata and L. saxatilis. are notably absent.Classification history of this biotope or habitat type
| Classification version | Code |
|---|---|
| 1997 (97.06) | SLR.FvesX |
| 1995 | LMXD.FVES |
Photos
