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Marine Habitat Classification

Description of biotope or habitat type

To understand more about what this page is describing, see How to use the classification. See also How to cite.

   Circalittoral caves and overhangs

Physical habitat description

Salinity Full (30-35 ppt)
Wave exposure Very exposed, Exposed, Moderately exposed, Sheltered
Tidal streams Weak (>1 kn), Very weak (negligible)
Substratum Bedrock
Zone Circalittoral
Depth Band 10-20 m, 20-30 m, 30-50 m
Other Features Caves, overhanging rock

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.

Distribution of habitat CR.FCR.Cv Circalittoral caves and overhangs

  • 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.


Caves and overhanging rock in the circalittoral zone, away from significant influence of strong wave action (compare FIR.SG). This habitat may be colonised by a wide variety of species, with sponges such as Dercitus bucklandi, anemones Parazoanthus spp. and the cup corals Caryophyllia inornatus, Hoplangia durotrix and others particularly characteristic.


No situation data available.

Temporal variation

No temporal variation data available.

Characterising species

Taxon Typical abundance - SACFOR scale % of core records where taxon was recorded
Alcyonium glomeratum Rare 41-60%
Balanophyllia regia Common 21-40%
Bryozoa indet crusts Frequent 41-60%
Caryophyllia smithii Common 61-80%
Clavelina lepadiformis Occasional 41-60%
Corynactis viridis Frequent 41-60%
Crisiidae Common 41-60%
Hoplangia durotrix Rare 21-40%
Leptopsammia pruvoti Common 21-40%
Porifera indet crusts Occasional 41-60%

Similar biotopes or habitat types

Not applicable or unknown.

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