Description of biotope or habitat type
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Bifurcaria bifurcata in shallow eulittoral rockpools
Physical habitat description
| Salinity | Full (30-35 ppt) |
|---|---|
| Wave exposure | Very exposed, Exposed, Moderately exposed |
| Tidal streams | |
| Substratum | Bedrock |
| Zone | Eulittoral |
| Depth Band | |
| Other Features | Rockpool |
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'
Point data based on records in the UK Marine Recorder Snapshot.
Description
Eulittoral rockpools in south-west Britain on very exposed to moderately exposed shores dominated by the brown seaweed Bifurcaria bifurcata and encrusting coralline algae and Corallina officinalis. Kelps are present and include the species Laminaria digitata, Saccharina latissima and the wrack Himanthalia elongata. Underneath the canopy formed by these species is a high diversity of red seaweeds including the foliose species Chondrus crispus, Palmaria palmata, Osmundea pinnatifida and Mastocarpus stellatus. Other red seaweeds include Gastroclonium ovatum, Ceramium nodulosum, Calliblepharis jubata and Mesophyllum lichenoides. The green seaweeds Ulva lactuca and Ulva intestinalis occur where space allows. Often found in small cracks and crevices are the anemones Actinia equina and Anemonia viridis, while the limpet Patella vulgata can be found on the rock surface. Coarse gravel, cobbles and mobile boulders often cover the bottom of these rockpools, where Steromphala umbilicalis can be found.
Situation
Rockpools throughout the eulittoral to the upper littoral fringe in bedrock on very exposed to moderately exposed shores. B. bifurcata is at the edge of its range in Britain; in France it occurs in deeper lower shore pools where the alga forms a noticeable band in the mid pool level, below a band of C. officinalis and coralline crusts.
Temporal variation
The ephemeral green seaweeds Enteromorpha intestinalis and Ulva lactuca can occur during the summer.
Characterising species
| Taxon | Relative importance of taxon for defining this community (%) | Typical abundance - SACFOR scale | % of core records where taxon was recorded |
|---|---|---|---|
| Corallina officinalis | 21 | Abundant | 81-100% |
| Bifurcaria bifurcata | 13 | Common | 81-100% |
| Corallinaceae | 12 | Abundant | 61-80% |
| Ulva lactuca | 7 | Occasional | 61-80% |
| Laminaria digitata | 4 | Frequent | 41-60% |
| Actinia equina | 3 | Occasional | 41-60% |
| Ulva intestinalis | 3 | Frequent | 41-60% |
| Gastroclonium ovatum | 3 | Occasional | 41-60% |
| Himanthalia elongata | 3 | Frequent | 41-60% |
| Anemonia viridis | 2 | Occasional | 41-60% |
| Calliblepharis jubata | 2 | Occasional | 41-60% |
| Ceramium nodulosum | 2 | Occasional | 41-60% |
| Chondrus crispus | 2 | Frequent | 41-60% |
| Palmaria palmata | 2 | Occasional | 41-60% |
| Steromphala umbilicalis | 1 | Frequent | 21-40% |
| Mastocarpus stellatus | 1 | Occasional | 21-40% |
| Mesophyllum lichenoides | 1 | Occasional | 21-40% |
| Osmundea pinnatifida | 1 | Occasional | 41-60% |
| Patella vulgata | 1 | Frequent | 21-40% |
Similar biotopes or habitat types
LR.FLR.Rkp.Cor.Cor
Occurs in similar physical conditions at a wide range of wave exposure. Winkles such as Littorina littorea and Littorina saxatilis can be present and the diversity of red seaweeds is lower. The brown seaweed B. bifurcata is absent.
LR.FLR.Rkp.Cor.Par
Occurs at extremely exposed and exposed shores. The diversity of red seaweeds is low due the grazing pressure of the sea urchin Paracentrotus lividus, which dominates this biotope. The brown seaweed B. bifurcata is absent.
LR.FLR.Rkp.Cor.Cys
Occurs in similar physical conditions. The brown seaweed Cystoseira spp. dominates, though species such as Scytosiphon lomentaria, Laminaria digitata and Laminaria hyperborea are usually present (Rare to Occasional).Photos
