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Marine Habitat Classification

Description of biotope or habitat type

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   Laminaria hyperborea on tide-swept infralittoral mixed substrata

Physical habitat description

Salinity Full (30-35 ppt)
Wave exposure Exposed, Moderately exposed, Sheltered
Tidal streams Strong (3-6 kn), Moderately strong (1-3 kn), Weak (>1 kn)
Substratum Boulders, cobbles, pebbles and gravel
Zone Infralittoral
Depth Band 0-5 m, 5-10 m, 10-20 m, 20-30 m
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.LhypTX <I>Laminaria hyperborea</I> on tide-swept infralittoral mixed substrata

  • 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.


Wave-exposed through to wave-sheltered, tide-swept infralittoral mixed substrata with Laminaria hyperborea forest/park and other kelp species such as Saccharina latissima. The rich under-storey and stipe flora is characterised by foliose seaweeds including the brown algae Dictyota dichotoma. The kelp stipes support epiphytes such as Cryptopleura ramosa, Metacallophyllis laciniata and Phycodrys rubens. At some sites, instead of being covered by red seaweeds, the kelp stipes are heavily encrusted by the ascidians Botryllus schlosseri and the bryozoan Alcyonidium diaphanum. Epilithic seaweeds such as Desmerestia aculeata, Odonthalia dentate, Delesseria sanguinea, Plocamium cartilagineum, Metacallophyllis laciniata, and crustose seaweeds commonly occur beneath the kelp. The kelp fronds are often covered with growths of the hydroid Obelia geniculata or the bryozoan Membranipora membranacea. On the rock surface, a rich fauna comprising anthozoans such as Alcyonium digitatum and Urticina felina, colonial ascidians such as Clavelina lepadiformis and the calcareous tubeworm Spirobranchus triqueter occurs. More mobile species include the gastropods Gibulla cineria and Calliostoma zizyphinum, the crab Cancer pagurus and the echinoderms Crossaster papposus, Henricia oculata, Asterias rubens and Echinus esculentus. Two variants are described; tide-swept kelp forest on upper infralittoral mixed substrata (LhypTX.Ft) and tide-swept kelp park on lower infralittoral mixed substrata (LhypTX.Pk).


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
Laminaria hyperborea 6 81-100%
Echinus esculentus 5 61-80%
Asterias rubens 4 61-80%
Calliostoma zizyphinum 4 61-80%
Delesseria sanguinea 4 61-80%
Plocamium cartilagineum 4 61-80%
Phycodrys rubens 3 61-80%
Alcyonidium diaphanum 2 41-60%
Botryllus schlosseri 2 41-60%
Metacallophyllis laciniata 2 41-60%
Cancer pagurus 2 41-60%
Cryptopleura ramosa 2 41-60%
Dictyota dichotoma 2 41-60%
Steromphala cineraria 2 41-60%
Odonthalia dentata 2 41-60%
Spirobranchus triqueter 2 41-60%
Lithophyllum 2 41-60%
Membranipora membranacea 1 21-40%
Alcyonium digitatum 1 41-60%
Clavelina lepadiformis 1 21-40%
Crossaster papposus 1 41-60%
Desmarestia aculeata 1 21-40%
Henricia oculata 1 21-40%
Obelia geniculata 1 21-40%
Urticina felina 1 Rare 41-60%

Similar biotopes or habitat types

Found under similar wave exposure and tidal stream conditions, but on bedrock and boulder substratum.

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