Description of biotope or habitat type
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Infralittoral rock (and other hard substrata)
Physical habitat description
Salinity | Full (30-35 ppt), Variable (18-35 ppt) |
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Wave exposure | Extremely exposed, Very exposed, Exposed, Moderately exposed, Sheltered, Very sheltered, Extremely sheltered |
Tidal streams | Very strong (>6 kn), Strong (3-6 kn), Moderately strong (1-3 kn), Weak (>1 kn), Very weak (negligible) |
Substratum | Bedrock; boulders, cobbles; mixed substrata |
Zone | Infralittoral, Sublittoral fringe |
Depth Band | 0-5 m, 5-10 m, 10-20 m, 20-30 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
Infralittoral rock includes habitats of bedrock, boulders and cobbles which occur in the shallow subtidal zone and typically support seaweed communities. The upper limit is marked by the top of the kelp zone whilst the lower limit is marked by the lower limit of kelp growth or the lower limit of dense seaweed growth. Infralittoral rock typically has an upper zone of dense kelp (forest) and a lower zone of sparse kelp (park), both with an understorey of erect seaweeds. In exposed conditions the kelp is Laminaria hyperborea whilst in more sheltered habitats it is usually Saccharina latissima; other kelp species may dominate under certain conditions. On the extreme lower shore and in the very shallow subtidal (sublittoral fringe) there is usually a narrow band of dabberlocks Alaria esculenta (exposed coasts) or the kelps Laminaria digitata (moderately exposed) or L. saccharina (very sheltered). Areas of mixed ground, lacking stable rock, may lack kelps but support seaweed communities. In estuaries and other turbid-water areas the shallow subtidal may be dominated by animal communities, with only poorly developed seaweed communities.
Situation
No situation data available.
Temporal variation
No temporal variation data available.
Characterising species
Characterising species data not applicable.
Similar biotopes or habitat types
Not applicable or unknown.
Classification history of this biotope or habitat type
Classification version | Code |
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1996 (6.95) | SR (part) |