Description of biotope or habitat type
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Mixed faunal turf communities
Physical habitat description
| Salinity | Full (30-35 ppt) |
|---|---|
| Wave exposure | Extremely exposed, Very exposed, Exposed, Moderately exposed |
| Tidal streams | Strong (3-6 kn), Moderately strong (1-3 kn) |
| Substratum | Bedrock, boulders |
| Zone | Circalittoral - lower, Circalittoral - upper |
| Depth Band | 5-10 m, 10-20 m, 20-30 m |
| Other Features |
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'
- Predicted extent of the level 3 (for sublittoral rock & deep sea) or 4 (for sublittoral sediment) habitat
Point data based on records in the UK Marine Recorder Snapshot. Predicted habitat extent is from UKSeaMap.
Description
This biotope complex occurs on wave-exposed circalittoral bedrock and boulders, subject to tidal streams ranging from strong to moderately strong. This complex is characterised by its diverse range of hydroids (Halecium halecinum, Nemertesia antennina and Nemertesia ramosa), bryozoans (Alcyonidium diaphanum, Flustra foliacea, Bugulina flabellata and Crisularia plumosa) and sponges (Sycon ciliatum, Pachymatisma johnstonia, Cliona celeta, Raspailia ramosa, Amphilectus fucorum, Hemimycale columella and Dysidea fragilis) forming an often dense, mixed faunal turf. Other species found within this complex are Alcyonium digitatum, Urticina felina, Cylista elegans, Actinothoe sphyrodeta, Caryophyllia smithii, Spirobranchus triqueter, Balanus crenatus, Cancer pagurus, Necora puber, Asterias rubens, Echinus esculentus and Clavelina lepadiformis. Nine biotopes have been identified within this complex: ByErSp, FluCoAs, FluHocu, CvirCri, SwiLgAs, Mol, SubCriTf, SpNemAdia and SpAnVt.
Situation
No situation data available.
Temporal variation
No temporal variation data available.
Characterising species
| Taxon | Typical abundance - SACFOR scale | % of core records where taxon was recorded |
|---|---|---|
| Actinothoe sphyrodeta | Occasional | 41-60% |
| Alcyonidium diaphanum | Frequent | 61-80% |
| Alcyonium digitatum | Frequent | 81-100% |
| Amphilectus fucorum | Occasional | 41-60% |
| Asterias rubens | Frequent | 81-100% |
| Balanus crenatus | Frequent | 41-60% |
| Bugulina flabellata | Occasional | 41-60% |
| Calliostoma zizyphinum | Occasional | 41-60% |
| Cancer pagurus | Occasional | 41-60% |
| Caryophyllia smithii | Frequent | 41-60% |
| Clavelina lepadiformis | Occasional | 41-60% |
| Cliona celata | Occasional | 61-80% |
| Crisularia plumosa | Frequent | 41-60% |
| Cylista elegans | Occasional | 41-60% |
| Dysidea fragilis | Occasional | 41-60% |
| Echinus esculentus | Occasional | 41-60% |
| Flustra foliacea | Frequent | 61-80% |
| Halecium halecinum | Occasional | 41-60% |
| Hemimycale columella | Occasional | 41-60% |
| Necora puber | Occasional | 41-60% |
| Nemertesia antennina | Frequent | 61-80% |
| Nemertesia ramosa | Occasional | 41-60% |
| Pachymatisma johnstonia | Occasional | 41-60% |
| Raspailia ramosa | Occasional | 41-60% |
| Spirobranchus triqueter | Occasional | 41-60% |
| Sycon ciliatum | Occasional | 41-60% |
| Urticina felina | Occasional | 41-60% |
Similar biotopes or habitat types
Not applicable or unknown.
Classification history of this biotope or habitat type
| Classification version | Code |
|---|---|
| 1997 (97.06) | CR.MCR.XFa |