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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.

   Kelp and red seaweeds (moderate energy infralittoral rock)

Physical habitat description

Salinity Full (30-35 ppt)
Wave exposure Exposed, Moderately exposed, Sheltered
Tidal streams Moderately strong (1-3 kn), Weak (>1 kn), Very weak (negligible)
Substratum Bedrock & boulders
Zone Infralittoral, Sublittoral fringe
Depth Band 0-5 m, 5-10 m, 10-20 m, Lower shore
Other Features

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 IR.MIR.KR Kelp and red seaweeds (moderate energy infralittoral rock)

  • 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.


Infralittoral rock subject to moderate wave exposure, or moderately strong tidal streams on more sheltered coasts. On bedrock and stable boulders there is typically a narrow band of kelp Laminaria digitata in the sublittoral fringe which lies above a Laminaria hyperborea forest and park. Associated with the kelp are communities of seaweeds, predominantly reds and including a greater variety of more delicate filamentous types than found on more exposed coasts (KFaR). The faunal component of the understorey is also less prominant than in KFaR.


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 digitatum Occasional 21-40%
Antedon bifida Occasional 1-20%
Asterias rubens Occasional 41-60%
Balanus crenatus Frequent 21-40%
Botryllus schlosseri Occasional 21-40%
Bryozoa indet crusts Frequent 21-40%
Calliostoma zizyphinum Occasional 21-40%
Cancer pagurus Rare 21-40%
Caryophyllia smithii Occasional 21-40%
Chondrus crispus Occasional 21-40%
Clavelina lepadiformis Occasional 21-40%
Corallina officinalis Frequent 21-40%
Corallinaceae Common 41-60%
Cryptopleura ramosa Frequent 21-40%
Cylista elegans Occasional 21-40%
Delesseria sanguinea Frequent 41-60%
Dictyota dichotoma Frequent 21-40%
Dilsea carnosa Occasional 21-40%
Echinus esculentus Frequent 41-60%
Electra pilosa Frequent 21-40%
Halichondria panicea Occasional 21-40%
Hypoglossum hypoglossoides Occasional 21-40%
Laminaria digitata Abundant 41-60%
Laminaria hyperborea Common 61-80%
Membranipora membranacea Frequent 21-40%
Membranoptera alata Occasional 21-40%
Metacallophyllis laciniata Occasional 21-40%
Necora puber Occasional 21-40%
Obelia geniculata Frequent 21-40%
Ophiothrix fragilis Occasional 21-40%
Pagurus bernhardus Occasional 21-40%
Palmaria palmata Frequent 21-40%
Phycodrys rubens Frequent 41-60%
Plocamium cartilagineum Frequent 41-60%
Saccharina latissima Occasional 21-40%
Spirobranchus triqueter Occasional 41-60%
Steromphala cineraria Occasional 41-60%
Sycon ciliatum Occasional 1-20%
Urticina felina Occasional 41-60%

Similar biotopes or habitat types

Not applicable or unknown.

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