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Marine Habitat Classification

Description of biotope or habitat type

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   Saccharina latissima and red seaweeds on infralittoral sediments

Physical habitat description

Salinity Full (30-35 ppt)
Wave exposure Extremely exposed, Exposed, Moderately exposed, Sheltered
Tidal streams Moderately strong (1-3 kn), Weak (>1 kn)
Substratum Small boulders, cobbles and pebbles with gravel
Zone Infralittoral
Depth Band 0-5 m, 5-10 m, 10-20 m, 20-30 m
Other Features

Biotope origin

Derived using data from Various
Faunal group Epifauna

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.SMp.KSwSS.SlatR <I>Saccharina latissima</I> and red seaweeds on infralittoral sediments

  • 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.


On infralittoral mixed muddy substrata communities characterised by the kelp Saccharina latissima and mixed filamentous and foliose red algae can be found. This biotope contains a number of sub-biotopes distinguished by the degree of either wave or tidal exposure. In moderately strong tidal streams in exposed areas Laminaria is sparse and dense stands of red seaweeds are found attached to the boulders and cobbles that make up a large proportion of the sediment (SS.SMp.KSwSS.SlatR.CbPb). As the degree of wave and/or tidal exposure decreases there is a change in community structure, with the density of Laminaria and the diversity of red algal species increasing (SS.SMp.KSwSS.SlatR.Gv). As the environment becomes more stable a few brown algal species are able to inhabit this environment and a rich infauna develops (SS.SMp.KSwSS.SlatR.Sa). In the most sheltered examples of this biotope a diverse muddy sediment infauna can be found and the 'Trailliella' phase of Bonnemaisonia hamifera may develop (SS.SMp.KSwSS.SlatR.Mu).


No situation data available.

Temporal variation

No temporal data available.

Characterising species

Taxon Relative importance of taxon for defining this community (%) Typical abundance - SACFOR scale % of core records where taxon was recorded
Asterias rubens 7 Occasional 61-80%
Saccharina latissima 7 Occasional 61-80%
Pagurus bernhardus 6 Occasional 61-80%
Plocamium cartilagineum 4 Occasional 41-60%
Liocarcinus depurator 3 Occasional 41-60%
Corallinaceae 2 Occasional 41-60%
Bonnemaisonia asparagoides 2 Occasional 21-40%
Vertebrata byssoides 2 Occasional 41-60%
Cerianthus lloydii 2 Occasional 41-60%
Desmarestia aculeata 2 Occasional 21-40%
Desmarestia viridis 2 Occasional 21-40%
Dictyota dichotoma 2 Occasional 21-40%
Steromphala cineraria 2 Occasional 41-60%
Halarachnion ligulatum 2 Occasional 21-40%
Lanice conchilega 2 Occasional 21-40%
Phycodrys rubens 2 Occasional 21-40%
Carradoriella elongata 2 Occasional 21-40%
Spirobranchus triqueter 2 Occasional 41-60%
Seraphsidae 2 Occasional 21-40%
Echinus esculentus 2 Occasional 41-60%
Ulva 2 Occasional 21-40%
Chaetopterus variopedatus 1 Occasional 21-40%
Chorda filum 1 Occasional 21-40%
Delesseria sanguinea 1 Occasional 21-40%
Gibbula magus 1 Occasional 21-40%
Lomentaria clavellosa 1 Occasional 21-40%
Pterothamnion plumula 1 Occasional 21-40%
Rhodophyllis divaricata 1 Occasional 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.SMp.KSwSS.LsacR Laminaria latissima and red seaweeds on infralittoral sediments
2004 (04.05) SS.SMp.KSwSS.LsacR Laminaria latissima and red seaweeds on infralittoral sediments
1997 (97.06) Part of SS.IMX.KSxMx.LsacX Laminaria saccharina, Chorda filum and filamentous red seaweeds on sheltered infralittoral sediment
1997 (97.06) Part of SS.MIR.SedK.EphR Ephemeral red seaweeds and kelps on tide-swept mobile infralittoral cobbles

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