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Marine Habitat Classification

Description of biotope or habitat type

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   Sponges and anemones on vertical circalittoral bedrock

Physical habitat description

Salinity Full (30-35 ppt)
Wave exposure Very exposed, Exposed, Moderately exposed
Tidal streams Strong (3-6 kn), Moderately strong (1-3 kn), Weak (>1 kn), Very weak (negligible)
Substratum Bedrock
Zone Infralittoral - lower, Circalittoral
Depth Band 10-20 m, 20-30 m, 30-50 m
Other Features Vertical 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.HCR.XFa.SpAnVt Sponges and anemones on vertical circalittoral bedrock

  • 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.


This biotope is found on exposed to moderately wave exposed , vertical and overhanging, circalittoral bedrock, subject to strong through to weak tidal streams. This biotope is characterised by a mixed faunal turf of hydroids (Nemertesis antennina, Tubularia indivisa and Halecium halecium) and bryozoans (Alcyonidium diaphanum and crisiid turf). There is frequently a diverse range of sponges recorded, including Cliona celata, Pachymatisma johnstonia, Dysidea fragilis and Hemimycale columella. There may be dense aggregation of dead mans fingers Alcyonium digitatum along with clumps of the cup coral Caryophyllia smithii, and the anthozoans Corynactis viridis, Actinothoe sphyrodeta, Cylista elegans and Metridium senile. Other species present include the echinoderms Echinus esculentus, Asterias rubens, Marthasterias glacialis, Henricia oculata, Holothuria (Panningothuria) forskali and Antedon bifida, clumps of the lightbulb tunicate Clavelina lepadiformis and the top shell Calliostoma zizyphinum. Three regional variations of this biotope have been recorded. The first variant is characterised by a Bugula turf along with the pink sea fan Eunicella verrucosa, and has been recorded from around southwest England and Wales. The second variant, characterised by a dense 'carpet' of Corynactis viridis and Metridium senile has been recorded predominantly from the west coast of Ireland. The final variant is characterised by a very diverse, dense faunal turf of hydroids, bryozoans and ascidians and has been recorded from the coasts around Northern Ireland.


No situation data available.

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
Alcyonium digitatum 10 Frequent 81-100%
Corynactis viridis 10 Frequent 61-80%
Caryophyllia smithii 9 Frequent 81-100%
Cliona celata 5 Occasional 61-80%
Echinus esculentus 5 Occasional 61-80%
Asterias rubens 4 Occasional 61-80%
Actinothoe sphyrodeta 3 Occasional 41-60%
Marthasterias glacialis 3 Occasional 41-60%
Nemertesia antennina 3 Occasional 41-60%
Calliostoma zizyphinum 2 Occasional 41-60%
Clavelina lepadiformis 2 Occasional 41-60%
Dysidea fragilis 2 Occasional 41-60%
Henricia oculata 2 Occasional 41-60%
Holothuria (Panningothuria) forskali 2 Occasional 21-40%
Pachymatisma johnstonia 2 Occasional 41-60%
Cylista elegans 2 Occasional 41-60%
Tubularia indivisa 2 Occasional 41-60%
Alcyonidium diaphanum 1 Rare 21-40%
Antedon bifida 1 Occasional 21-40%
Crisiidae 1 Frequent 21-40%
Halecium halecinum 1 Occasional 21-40%
Hemimycale columella 1 Occasional 21-40%
Metridium senile 1 Occasional 21-40%

Similar biotopes or habitat types

Not applicable or unknown.

Classification history of this biotope or habitat type

Classification version Code

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