Biodiversity & Conservation

Overhangs and caves



Image Keith Hiscock - A well developed overhang community with pendulous polyclinid tunicates. Image width ca 1 m.
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Distribution map

LR.FLR.CvOv recorded (dark blue bullet) and expected (light blue bullet) distribution in Britain and Ireland (see below)

  • EC_Habitats

For a list of 2004 characterising species please see the JNCC website.

Map icon UK and Ireland classification

Major habitat LR Littoral rock (and other hard substrata)
Habitat complex LR.FLR Features of littoral rock
Biotope complex LR.FLR.CvOv Littoral caves and overhangs

Additional information icon Additional information

The biotope complex LR.Ov is used to represent two biotopes:

LR.Ov.SR (Sponges and shade-tolerant red seaweeds on overhanging lower eulittoral bedrock) includes both encrusting and pendulous species and shade tolerant algae. It may be found from very sheltered to very exposed situations in full or variable salinity.

LR.Ov.SByAs (Sponges, bryozoans and ascidians on deeply overhanging lower shore bedrock) includes predominantly encrusting species but with few or no algae. It may be found from very sheltered to moderately exposed conditions in full salinity.

A third biotope (LR.RhoCv: Rhodothamniella floridula in upper littoral fringe soft rock caves) has been assessed separately (see review).

This review can be cited as follows:

Hiscock, K. 2002. Overhangs and caves. Marine Life Information Network: Biology and Sensitivity Key Information Sub-programme [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 26/11/2015]. Available from: <>