Description of biotope or habitat type
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Sertularia cupressina and Hydrallmania falcata on tide-swept sublittoral sand with cobbles or pebbles.
Physical habitat description
| Salinity | Full (30-35 ppt) |
|---|---|
| Wave exposure | Moderately exposed, Sheltered |
| Tidal streams | Strong (3-6 kn), Moderately strong (1-3 kn), Weak (>1 kn) |
| Substratum | Medium to fine sand with pebbles and cobbles |
| Zone | Circalittoral, Infralittoral |
| Depth Band | 0-5 m, 5-10 m, 10-20 m |
| Other Features |
Biotope origin
| Derived using data from | Various |
| Faunal group | Epifauna |
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
Shallow sands with cobbles and pebbles, exposed to strong tidal streams, with conspicuous colonies of hydroids, particularly Hydrallmania falcata and to a lesser extent Sertularia cupressina and S. argentea. These hydroids are tolerant to periodic submergence and scour by sand. Both diving and dredge surveys will easily record this biotope. Flustra foliacea, Balanus crenatus and Alcyonidium diaphanum may also occur on the more stable cobbles and pebbles, with Urticina felina and occasional Lanice conchilega present in the sand. Infaunal components of the other biotopes in the SS.SSa or SS.SCS complexes may occur in this biotope as may elements of the 'Venus' associations; indeed, this biotope may be at one extreme of the spectrum of such associations (E.I.S. Rees pers. comm. 1997) and may be best considered an epibiotic overlay.
Situation
No situation data available.
Temporal variation
No temporal data available.
Characterising species
| Taxon | Relative importance of taxon for defining this community (%) | Typical abundance - SACFOR scale | % of core records where taxon was recorded |
|---|---|---|---|
| Hydrallmania falcata | 18 | Occasional | 61-80% |
| Pagurus bernhardus | 12 | Rare | 61-80% |
| Sertularia cupressina | 12 | 41-60% | |
| Lanice conchilega | 11 | Occasional | 61-80% |
| Urticina felina | 8 | Rare | 41-60% |
| Alcyonidium diaphanum | 6 | Occasional | 41-60% |
| Asterias rubens | 5 | Occasional | 41-60% |
| Carcinus maenas | 5 | 41-60% | |
| Balanus crenatus | 4 | Rare | 41-60% |
| Sertularia argentea | 3 | Occasional | 21-40% |
| Flustra foliacea | 2 | Rare | 21-40% |
| Liocarcinus depurator | 1 | Rare | 21-40% |
| Mytilus edulis | 1 | 21-40% | |
| Sabella pavonina | 1 | Rare | 21-40% |
Similar biotopes or habitat types
SS.SMx.CMx.FluHyd
The less scoured biotope SS.SMx.CMx.FluHyd occurs in deeper water where there is less sand and a higher proportion of stones and cobbles.Classification history of this biotope or habitat type
| Classification version | Code | Habitat name |
|---|---|---|
| 2015 (15.03) | SS.SSa.IFiSa.ScupHyd | Sertularia cupressina and Hydrallmania falcata on tide-swept sublittoral sand with cobbles or pebbles |
| 2004 (04.05) | SS.SSa.IFiSa.ScupHyd | Sertularia cupressina and Hydrallmania falcata on tide-swept sublittoral sand with cobbles or pebbles |
| 1997 (97.06) | SS.IGS.FaS.ScupHyd | Sertularia cupressina and Hydrallmania falcata on tide-swept sublittoral cobbles or pebbles in coarse sand |
| 1996 (6.95) | IGS.Scup | Sertularia cupressina on tide-swept sublittoral cobbles or pebbles in coarse sand |