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Marine Habitat Classification

Description of biotope or habitat type

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   Sublittoral mussel beds (on sublittoral sediment)

Physical habitat description

Salinity Full (30-35 ppt)
Wave exposure Moderately exposed, Sheltered, Very sheltered, Extremely sheltered
Tidal streams Strong (3-6 kn), Moderately strong (1-3 kn), Weak (>1 kn), Very weak (negligible)
Substratum Muddy sand, sandy muds, gravel and pebbles
Zone Infralittoral - lower, Circalittoral
Depth Band 0-5 m, 5-10 m, 10-20 m, 20-30 m
Other Features

Biotope origin

Derived using data from Video
Faunal group Epifauna/infauna

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 SS.SBR.SMus Sublittoral mussel beds (on sublittoral sediment)

  • 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.


Sublittoral mussel beds comprised of either the horse mussel Modiolus modiolus or the common mussel Mytilus edulis. These communities may be sublittoral extensions of littoral reefs or exist independently. Found in a variety of habitats ranging from sheltered estuaries and marine inlets to open coasts and offshore areas. Mussel beds can be found on a range of substrata, although due to the stabilising effect such communities have on the substratum muddy mixed sediments are typical. A diverse range of epibiota and infauna often exists in these communities.


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
Modiolus modiolus 20 Abundant 81-100%
Mytilus edulis 16 Super abundant 21-40%
Oligochaeta 10 Abundant 21-40%
Ophiothrix fragilis 10 Frequent 61-80%
Asterias rubens 8 Occasional 61-80%
Gammarus salinus 8 Super abundant 21-40%
Nemertea 7 Abundant 61-80%
Pagurus bernhardus 6 Occasional 61-80%
Echinus esculentus 6 Occasional 61-80%
Buccinum undatum 4 Occasional 41-60%
Aequipecten opercularis 3 Frequent 21-40%
Harmothoe impar 3 Abundant 21-40%
Spirobranchus triqueter 3 Frequent 21-40%
Cirripedia 2 Common 21-40%
Turbellaria 2 Frequent 21-40%
Corallinaceae 2 Frequent 21-40%
Alcyonium digitatum 2 Occasional 21-40%
Balanus crenatus 2 Frequent 21-40%
Capitella capitata 2 Common 21-40%
Crossaster papposus 2 Rare 41-60%
Eteone longa 2 Common 21-40%
Heteromastus filiformis 2 Common 21-40%
Hyas araneus 2 Occasional 21-40%
Psamathe fusca 2 Super abundant 21-40%
Ophiocomina nigra 2 Frequent 21-40%
Phycodrys rubens 2 Frequent 21-40%
Spirobranchus 2 Frequent 21-40%
Spirobranchus triqueter 2 Abundant 21-40%
Anthozoa 1 Abundant 21-40%
Antedon bifida 1 Occasional 21-40%
Balanus balanus 1 Occasional 21-40%
Corella parallelogramma 1 Occasional 21-40%
Dendrodoa grossularia 1 Occasional 21-40%
Steromphala cineraria 1 Occasional 21-40%
Harmothoe imbricata 1 Super abundant 21-40%
Liocarcinus depurator 1 Occasional 21-40%
Scoloplos armiger 1 Abundant 21-40%
Urticina felina 1 Occasional 21-40%
Nucella lapillus 1 Common 21-40%

Similar biotopes or habitat types

Not applicable or unknown.

Classification history of this biotope or habitat type

Classification version Code Habitat name
2015 (15.03) SS.SBR.SMus Sublittoral mussel beds (on sublittoral sediment)
2004 (04.05) SS.SBR.SMus Sublittoral mussel beds (on sublittoral sediment)
1997 (97.06) SS.CR.SCR.Mod Sheltered Modiolus (horse-mussel) beds

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