Description of biotope or habitat type
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Rockpools
Physical habitat description
| Salinity | Full (30-35 ppt), Variable (18-35 ppt) |
|---|---|
| Wave exposure | Very exposed, Exposed, Moderately exposed, Sheltered |
| Tidal streams | |
| Substratum | Bedrock |
| Zone | Eulittoral, Littoral fringe, Supralittoral |
| Depth Band | Lower shore, Mid shore, Upper 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'
Point data based on records in the UK Marine Recorder Snapshot.
Description
Rockpools occur where the topography of the shore allows seawater to be retained within depressions in the bedrock producing 'pools' on the retreat of the tide. As these rockpool communities are permanently submerged they are not directly affected by height on the shore and normal rocky shore zonation patterns do not apply. For this reason rockpools have been dealt with as a separate biotope complex, apart from the scheme of wave exposure and shore height. Four main rockpool biotopes have been described, and although it is accepted that an enormous variety of rockpool communities exist, it is hoped that these biotope descriptions are broad enough to adequately encompass most types. It would be meaningless to include the characterising species in a description at the biotope complex level. Rockpools on the upper shore which are subject to rainwater influence and wide fluctuations in temperature are typically dominated by green seaweeds such as Ulva spp. and Cladophora spp. (G). Shallow rockpools in the mid to upper shore characterised by encrusting coralline algae and Corallina officinalis (Cor); several variants of these coralline pools occur in south-west Britain and Ireland (Cor.Par, Cor.Bif and Cor.Cys). Deeper rockpools on the mid to lower shore can support fucoids and some sublittoral species such as kelp (FK). Those rockpools influenced by the presence of sand are characterised by sand-tolerant seaweed such as Furcellaria lumbricalis and Polyides rotunda (SwSed). Where more stable sand occurs in the base of the rockpool sea-grass beds can occur (SwSed). Shallow rockpools on mixed cobbles, pebbles, gravel and sand may be characterised by hydroids (H). A very rough guideline to the terms "shallow" and "deep" rockpools: "shallow" rockpools do not support kelp, whereas "deep" rockpools do. This rockpool complex (LR.FLR.Rkp) does not include shallow standing water on compacted sediment or mixed substrata.
Situation
Rockpools occur in the littoral zone where the topography of the shore allows seawater to be retained within depressions in the bedrock producing 'pools' on the retreat of the tide.
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 |
|---|---|---|---|
| Corallinaceae | 20 | Abundant | 61-80% |
| Corallina officinalis | 19 | Common | 81-100% |
| Ulva intestinalis | 5 | Frequent | 41-60% |
| Littorina littorea | 5 | Common | 21-40% |
| Patella vulgata | 5 | Occasional | 41-60% |
| Ulva lactuca | 4 | Occasional | 41-60% |
| Actinia equina | 3 | Occasional | 41-60% |
| Chondrus crispus | 3 | Occasional | 41-60% |
| Laminaria digitata | 3 | Occasional | 41-60% |
| Ceramium nodulosum | 2 | Frequent | 21-40% |
| Fucus serratus | 2 | Occasional | 21-40% |
| Mastocarpus stellatus | 2 | Occasional | 21-40% |
| Mytilus edulis | 2 | Occasional | 21-40% |
| Cladophora | 1 | Occasional | 41-60% |
| Dumontia contorta | 1 | Occasional | 21-40% |
| Steromphala cineraria | 1 | Occasional | 21-40% |
| Palmaria palmata | 1 | Occasional | 21-40% |
| Nucella lapillus | 1 | Occasional | 21-40% |
Similar biotopes or habitat types
Not applicable or unknown.
Classification history of this biotope or habitat type
| Classification version | Code |
|---|---|
| 1996 (6.95) | RKP |