Description of biotope or habitat type
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Kelp with cushion fauna and/or foliose red seaweeds
Physical habitat description
| Salinity | Full (30-35 ppt) |
|---|---|
| Wave exposure | Extremely exposed, Very exposed, Exposed |
| Tidal streams | Moderately strong (1-3 kn), Weak (>1 kn), Very weak (negligible) |
| Substratum | Bedrock; stable boulders |
| Zone | Infralittoral, Sublittoral fringe |
| Depth Band | 0-5 m, 5-10 m, 10-20 m, 20-30 m, 30-50 m, Lower shore |
| 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
Rocky habitats in the infralittoral zone subject to exposed to extremely exposed wave action or strong tidal streams. Typically the rock supports a community of kelp Laminaria hyperborea with foliose seaweeds and animals, the latter tending to become more prominent in areas of strongest water movement (LhypFa, LhypR and LhypR.Pk). The depth to which the kelp extends varies according to water clarity, exceptionally (e.g. St Kilda) reaching 45 m. In some areas, there may be a band of dense foliose seaweeds (reds or browns) below the main kelp zone (FoR). The sublitttoral fringe is characterised by dabberlocks Alaria esculenta (Ala biotopes). In very strong wave action the sublittoral fringe A. esculenta zone extends to 5 to 10 m depth, whilst at Rockall A. esculenta replaces L. hyperborea as the dominant kelp in the infralittoral zone (AlaAnCrSp).
Situation
Very exposed rocky coasts, from low water to depths up to 45m.
Temporal variation
Winter storms may remove patches of kelp, and fast-growing annuals may form a temporary forest (LsacSac).
Characterising species
| Taxon | Typical abundance - SACFOR scale | % of core records where taxon was recorded |
|---|---|---|
| Alaria esculenta | Common | 41-60% |
| Alcyonium digitatum | Occasional | 21-40% |
| Asterias rubens | Occasional | 41-60% |
| Botryllus schlosseri | Occasional | 21-40% |
| Calliostoma zizyphinum | Occasional | 21-40% |
| Corallina officinalis | Frequent | 21-40% |
| Corallinaceae | Common | 61-80% |
| Corynactis viridis | Frequent | 21-40% |
| Cryptopleura ramosa | Frequent | 41-60% |
| Cylista elegans | Occasional | 21-40% |
| Delesseria sanguinea | Frequent | 41-60% |
| Dictyota dichotoma | Frequent | 41-60% |
| Echinus esculentus | Occasional | 21-40% |
| Laminaria hyperborea | Common | 41-60% |
| Metacallophyllis laciniata | Occasional | 21-40% |
| Plocamium cartilagineum | Frequent | 41-60% |
| Spirobranchus triqueter | Occasional | 21-40% |
| Urticina felina | Occasional | 21-40% |
Similar biotopes or habitat types
Not applicable or unknown.