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Marine Habitat Classification

Description of biotope or habitat type

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   Coralline crusts and Paracentrotus lividus in shallow eulittoral rockpools

Physical habitat description

Salinity Full (30-35 ppt)
Wave exposure Very exposed, 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.

Distribution of habitat LR.FLR.Rkp.Cor.Par Coralline crusts and <I>Paracentrotus lividus</I> in shallow eulittoral rockpools

  • 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.


Shallow and relatively smal rockpools throughout the eulittoral zone on very exposed to exposed shores, characterised by a covering of encrusting coralline algae on which Corallina officinalis forms a dense turf. The bottom of these pools can be covered in coarse gravel and cobbles. In south and west Ireland these coralline pools may be dominated by the sea urchin Paracentrotus lividus and the seaweed diversity is generally low due to the grazing pressure of P. lividus, the top shells Steromphala cineraria and Steromphala umbilicalis, and winkles such as Littorina littorea. Within the pools, pits and crevices are often occupied by the anemone such as Actinia equina and Anemonia viridis and small individuals of the mussel Mytilus edulis. The siphonous green seaweed Codium spp. can also be present along with the wrack Himanthalia elongata and the brown seaweed Leathesia marina and the filamentous red seaweed Ceramium spp. The barnacle Semibalanus balanoides is either absent or occurs at low abundance in these rockpools, presumably due to the grazing pressure on the larval stage and the predation pressure from the whelk Nucella lapillus. Soft bedrock, such as limestone, allows P. lividus to bore into the rock.


Rockpools throughout the eulittoral and lower littoral fringe in bedrock on very exposed to exposed shores.

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
Paracentrotus lividus 17 Common 81-100%
Corallinaceae 16 Abundant 81-100%
Corallina officinalis 11 Common 81-100%
Actinia equina 8 Frequent 81-100%
Patella vulgata 6 Frequent 61-80%
Ulva intestinaloides 5 Frequent 41-60%
Ulva lactuca 5 Occasional 61-80%
Steromphala umbilicalis 4 Occasional 61-80%
Ceramium 3 Occasional 61-80%
Littorina littorea 3 Common 41-60%
Codium 3 Occasional 41-60%
Nucella lapillus 2 Occasional 41-60%
Anemonia viridis 1 Rare 41-60%
Steromphala cineraria 1 Frequent 21-40%
Himanthalia elongata 1 Rare 41-60%
Leathesia marina 1 Occasional 41-60%
Mytilus edulis 1 Occasional 41-60%

Similar biotopes or habitat types

Occurs in similar physical conditions over a wide range of wave exposures. P. lividus is not present and foliose red seaweeds such as Mastocarpus stellatus and Chondrus crispus can be present.

Occurs in similar physical conditions. The brown seaweed Bifurcaria bifurcata dominate this biotope. The diversity of red seaweeds is higher, and includes species such as Palmaria palmata and Gastroclonium ovatum.

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).

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