Description of biotope or habitat type
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Very tide-swept faunal communities
Physical habitat description
Salinity | Full (30-35 ppt) |
---|---|
Wave exposure | Extremely exposed, Very exposed, Exposed |
Tidal streams | Very strong (>6 kn), Strong (3-6 kn) |
Substratum | Bedrock, boulders |
Zone | Circalittoral - lower, Circalittoral - upper |
Depth Band | 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 in wave-exposed, tide-swept narrows and straits on circalittoral bedrock and boulders. The biotopes within this complex are characterised by a high abundance of the robust hydroid Tubularia indivisa. The barnacle Balanus crenatus is characteristic of BalTub, the cushion sponges Halichondria panicea and Myxilla incrustans are characteristic of CTub.CuSp and Alcyonium digitatum is characteristic of CTub.Adig. The anemones Cylista elegans, Actinothoe sphyrodeta, Urticina felina, Corynactis viridis and Metridium senile are all found within this complex. Other species present in this high-energy complex are the sponges Amphilectus fucorum and Pachymatisma johnstonia, the bryozoans Alcyonidium diaphanum and Flustra foliacea, Cancer pagurus, Sertularia argentea and Asterias rubens. Within this complex, two biotopes have been identified: BalTub and CTub.
Situation
No situation data available.
Temporal variation
No temporal variation data available.
Characterising species
Taxon | Relative importance of taxon for defining this community (%) | Typical abundance - SACFOR scale | % of core records where taxon was recorded |
---|---|---|---|
Tubularia indivisa | 24 | Abundant | 81-100% |
Balanus crenatus | 11 | Abundant | 61-80% |
Cylista elegans | 9 | Common | 61-80% |
Alcyonium digitatum | 7 | Frequent | 61-80% |
Alcyonidium diaphanum | 3 | Frequent | 41-60% |
Amphilectus fucorum | 3 | Frequent | 41-60% |
Urticina felina | 3 | Frequent | 41-60% |
Actinothoe sphyrodeta | 2 | Common | 21-40% |
Asterias rubens | 2 | Occasional | 41-60% |
Cancer pagurus | 2 | Occasional | 41-60% |
Corynactis viridis | 2 | Frequent | 21-40% |
Flustra foliacea | 2 | Frequent | 21-40% |
Halichondria panicea | 2 | Frequent | 21-40% |
Myxilla incrustans | 2 | Frequent | 41-60% |
Pachymatisma johnstonia | 2 | Occasional | 41-60% |
Sertularia argentea | 2 | Occasional | 41-60% |
Porifera | 1 | Frequent | 21-40% |
Metridium senile | 1 | Frequent | 21-40% |
Similar biotopes or habitat types
Not applicable or unknown.
Classification history of this biotope or habitat type
Classification version | Code |
---|---|
1997 (97.06) | ECR.BS |