Description of biotope or habitat type
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Sabellaria spinulosa encrusted circalittoral rock
Physical habitat description
| Salinity | Full (30-35 ppt) |
|---|---|
| Wave exposure | Exposed, Moderately exposed |
| Tidal streams | Moderately strong (1-3 kn), Weak (>1 kn), Very weak (negligible) |
| Substratum | Bedrock, boulders, cobbles |
| Zone | Circalittoral |
| Depth Band | 10-20 m, 20-30 m, 30-50 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 is typically found encrusting the upper faces of wave-exposed and moderately wave-exposed circalittoral bedrock, boulders and cobbles subject to strong/moderately strong tidal streams in areas with high turbidity. The crusts formed by the sandy tubes of the polychaete worm Sabellaria spinulosa may even completely cover the rock, binding the substratum together to form a crust. A diverse fauna may be found attached to, and sometimes obscuring the crust, often reflecting the character of surrounding biotopes. Bryozoans such as Flustra foliacea, Pentapora foliacea and Alcyonidium diaphanum, anemones such as Urticina felina and Cylista elegans, the polychaete Spirobranchus triqueter, Alcyonium digitatum, the hydroid Nemertesia antennina and echinoderms such as Asterias rubens and Crossaster papposus may all be recorded within this biotope. There are two variants. The first (Sspi.ByB) contains significant cover of barnacles (Balanus crenatus) and bryozoans. The second (Sspi.As) has a dense turf of didemnid ascidians as well as scour-tolerant bryozoans such as F. foliacea, sponges such as Tethya aurantium and Phorbas fictitius, colonies of the serpulid worm Salmacina dysteri and patchy occurrences of the ascidians Distomus variolosus, Polycarpa pomaria and Polycarpa scuba. This biotope has been recorded from the Lleyn Peninsula, Lundy Island (including the wreck of the MV Robert) and the north-east and south coast of England.
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 |
|---|---|---|---|
| Sabellaria spinulosa | 30 | Common | 81-100% |
| Didemnidae | 12 | Frequent | 41-60% |
| Flustra foliacea | 8 | Occasional | 61-80% |
| Asterias rubens | 7 | Occasional | 61-80% |
| Urticina felina | 5 | Occasional | 41-60% |
| Alcyonium digitatum | 3 | Frequent | 21-40% |
| Distomus variolosus | 3 | Common | 21-40% |
| Spirobranchus triqueter | 3 | Frequent | 21-40% |
| Crossaster papposus | 2 | Occasional | 21-40% |
| Pentapora foliacea | 2 | Occasional | 21-40% |
| Polycarpa pomaria | 2 | Common | 21-40% |
| Alcyonidium diaphanum | 1 | Occasional | 21-40% |
| Balanus crenatus | 1 | Frequent | 21-40% |
| Nemertesia antennina | 1 | Occasional | 21-40% |
| Phorbas fictitius | 1 | Occasional | 21-40% |
| Polycarpa scuba | 1 | Common | 21-40% |
| Cylista elegans | 1 | Occasional | 21-40% |
| Salmacina dysteri | 1 | Occasional | 21-40% |
| Tethya aurantium | 1 | Occasional | 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) | CR.MCR.CSab.Sspi |
