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Marine Habitat Classification

Description of biotope or habitat type

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   Saccharina latissima with Psammechinus miliaris and/or Modiolus modiolus on variable salinity infralittoral mixed sediment

Physical habitat description

Salinity Full (30-35 ppt)
Wave exposure Exposed, Moderately exposed, Sheltered, Very sheltered
Tidal streams Moderately strong (1-3 kn), Weak (>1 kn), Very weak (negligible)
Substratum Mixed muddy sand with gravel, pebbles and cobbles
Zone Infralittoral
Depth Band 0-5 m, 5-10 m, 10-20 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.SlatMxVS <I>Saccharina latissima</I> with <I>Psammechinus miliaris</I> and/or <I>Modiolus modiolus</I> on variable salinity infralittoral mixed 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.


Shallow kelp community found on stony mixed sediment, in full or variable salinity, in sheltered or moderately exposed conditions, with weak or very weak tidal currents. The community is characterised by a dense covering of Saccharina latissima. Beneath the kelp canopy, frequent Psammechinus miliaris may be found grazing the algal turf and scattered Modiolus modiolus are characteristic of this biotope. Encrusting the suface of stones and pebbles are Spirobranchus triqueter and in the sediment between the stones, the burrowing anemone Cerianthus lloydii may also be present. Small patches of Lithothamnion glaciale may be found in this biotope, although these patches do not form distinct beds as in SS.SMp.Mrl.Lgla. In addition, a more ubiquitous fauna such as Asterias rubens and Pagurus bernhardus are also present. This biotope is generally found in sea lochs.


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
Saccharina latissima 20 Common 81-100%
Psammechinus miliaris 10 Frequent 61-80%
Pagurus bernhardus 9 Occasional 61-80%
Asterias rubens 8 Occasional 61-80%
Spirobranchus triqueter 8 Frequent 61-80%
Cerianthus lloydii 5 Common 41-60%
Modiolus modiolus 5 Occasional 61-80%
Corallinaceae 3 Frequent 41-60%
Buccinum undatum 3 Occasional 41-60%
Lithothamnion glaciale 3 Frequent 41-60%
Phycodrys rubens 3 Frequent 41-60%
Carcinus maenas 2 Occasional 41-60%
Chorda filum 2 Occasional 41-60%
Gobiusculus flavescens 2 Common 21-40%
Metridium senile 2 Occasional 21-40%
Mya truncata 1 Occasional 21-40%
Carradoriella elongata 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.LsacMxVS Laminaria saccharina with Psammechinus miliaris and/or Modiolus modiolus on variable salinity infralittoral sediment
2004 (04.05) SS.SMp.KSwSS.LsacMxVS Laminaria saccharina with Psammechinus miliaris and/or Modiolus modiolus on variable salinity infralittoral sediment

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