Description of biotope or habitat type
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Sabellaria spinulosa with a bryozoan turf and barnacles on silty turbid circalittoral rock
Physical habitat description
| Salinity | Full (30-35 ppt) |
|---|---|
| Wave exposure | Exposed, Moderately exposed |
| Tidal streams | Strong (3-6 kn), Moderately strong (1-3 kn) |
| Substratum | Bedrock, boulders, cobbles, pebbles, gravel, sand |
| Zone | Circalittoral |
| Depth Band | 0-5 m, 5-10 m, 10-20 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 variant is typically found encrusting the upper faces of exposed and moderately exposed circalittoral rock and mixed substrata, subject to strong and moderately strong currents and high turbidity levels. The crusts formed by the sandy tubes of the polychaete worm Sabellaria spinulosa may completely cover the rock, binding gravel and pebbles together. A diverse fauna may be found attached to this crust, and in many cases reflects the character of nearby biotopes. There is normally considerable variation in the associated fauna encountered. There may be a sparse bryozoan turf (Flustra foliacea, Alcyonidium diaphanum, Bicellariella ciliata, Crisularia plumosa and Vesicularia spinosa) attached to the Sabellaria crust and available rocky substrata. Other scour-tolerant species such as Urticina felina are occasionally observed. Clumps of robust hydroids such as Tubularia indivisa, Nemertesia antennina, Hydrallmania falcata and Halecium halecinum may also be observed. Other species which may be present include the polychaete Spirobranchus triqueter, Balanus crenatus, Asterias rubens, Pagurus bernhardus and Steromphala cineraria. Occasionally, sponges such as Haliclona oculata and Halichondria panicea, and ascidians such as Dendrodoa grossularia may also be observed.
Situation
No situation data available.
Temporal variation
Not known.
Characterising species
| Taxon | Relative importance of taxon for defining this community (%) | Typical abundance - SACFOR scale | % of core records where taxon was recorded |
|---|---|---|---|
| Sabellaria spinulosa | 22 | Abundant | 81-100% |
| Urticina felina | 9 | Occasional | 81-100% |
| Balanus crenatus | 6 | Frequent | 61-80% |
| Spirobranchus triqueter | 6 | Frequent | 41-60% |
| Flustra foliacea | 5 | Occasional | 61-80% |
| Asterias rubens | 4 | Occasional | 61-80% |
| Dendrodoa grossularia | 4 | Frequent | 61-80% |
| Tubularia indivisa | 4 | Occasional | 61-80% |
| Alcyonidium diaphanum | 3 | Occasional | 61-80% |
| Bicellariella ciliata | 3 | Frequent | 41-60% |
| Halichondria panicea | 3 | Frequent | 41-60% |
| Pagurus | 3 | Occasional | 81-100% |
| Buccinum undatum | 2 | Rare | 61-80% |
| Crisularia plumosa | 2 | Frequent | 21-40% |
| Haliclona oculata | 2 | Occasional | 41-60% |
| Hydrallmania falcata | 2 | Occasional | 41-60% |
| Nemertesia antennina | 2 | Occasional | 41-60% |
| Vesicularia spinosa | 2 | Occasional | 21-40% |
| Steromphala cineraria | 1 | Occasional | 21-40% |
| Halecium halecinum | 1 | Frequent | 21-40% |
Similar biotopes or habitat types
CR.MCR.CSab.Sspi.As
This biotope is found on the upper faces of moderately exposed, moderately tide-swept circalittoral bedrock, boulders and cobbles. This biotope is similar in that the polychaete S. spinulosa is the prevalent species. However, it is distinguished from CR.MCR.CSab.Sspi.ByB by a dense turf of didemnid, and other colonial ascidians such as Polycarpa sp.