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Marine Habitat Classification

Description of biotope or habitat type

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   Saccharina latissima with Phyllophora spp. and filamentous green seaweeds on variable or reduced salinity infralittoral rock

Physical habitat description

Salinity Reduced (18-30ppt), Low (<18ppt)
Wave exposure Sheltered, Very sheltered
Tidal streams Weak (>1 kn), Very weak (negligible)
Substratum Bedrock; boulders and cobbles
Zone Infralittoral
Depth Band 0-5 m, 5-10 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.LIR.KVS.SlatPhyVS <I>Saccharina latissima</I> with <I>Phyllophora</I> spp. and filamentous green seaweeds on variable or reduced salinity 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.


Shallow infralittoral bedrock or boulder slopes, in reduced or low salinity conditions, characterised by the kelp Saccharina latissima with dense stands of silted filamentous green seaweeds and red seaweeds Phyllophora crispa, Phyllophora pseudoceranoïdes and Phycodrys rubens. The filamentous green seaweeds e.g. Chaetomorpha melagonium and Cladophora spp. can form a blanket cover amongst the L. saccharina in the upper zone, which is under greater influence of freshwater input. In deeper water the green seaweeds are replaced by red seaweed Phyllophora spp. or Vertebrata fucoides which may form a distinct sub-zone in the biotope. Coralline crust can be present. The solitary ascidians Corella parallelogramma and Ascidiella scabra are often epiphytic on the seaweed (particularly Phyllophora spp.) and dominate the animal community along with the starfish Asterias rubens. The small ascidian Dendrodoa grossularia, the barnacle Balanus crenatus and the tube-building polychaete Spirobranchus triqueter occur on the rock surface. More mobile species include the crab Carcinus maenas, the hermit crab Pagurus bernhardus and the whelk Buccinum undatum. Bryozoans Electra pilosa and Spirorbis sp. may cover kelp fronds. The red seaweed Odonthalia dentata may be present in the north.


The ascidians found in LsacPhyVS may continue onto the circalittoral rock below where dense colonies of anthozoans and brachiopods can also be found (NeoPro.Den). Where tidal streams are increased, sponge and hydroid communities may occur below (HbowEud).

Temporal variation


Characterising species

Taxon Relative importance of taxon for defining this community (%) Typical abundance - SACFOR scale % of core records where taxon was recorded
Asterias rubens 12 Frequent 81-100%
Saccharina latissima 12 Frequent 81-100%
Phyllophora pseudoceranoides 9 Frequent 61-80%
Carcinus maenas 8 Occasional 81-100%
Corella parallelogramma 8 Frequent 61-80%
Phycodrys rubens 6 Occasional 61-80%
Phyllophora crispa 6 Frequent 61-80%
Ascidiella scabra 5 Frequent 41-60%
Electra pilosa 3 Common 41-60%
Balanus crenatus 3 Occasional 41-60%
Eucratea loricata 3 Occasional 41-60%
Pagurus bernhardus 3 Occasional 41-60%
Corallinaceae 2 Common 21-40%
Odonthalia dentata 2 Occasional 21-40%
Spirobranchus triqueter 2 Occasional 41-60%
Buccinum undatum 1 Occasional 21-40%
Dendrodoa grossularia 1 Occasional 21-40%
Filamentous green algae 1 Occasional 21-40%
Vertebrata fucoides 1 Occasional 21-40%

Similar biotopes or habitat types

Not applicable or unknown.

Classification history of this biotope or habitat type

Classification version Code
2015 (15.03) IR.LIR.KVS.LsacPhyVS
1997 (97.06) SIR.LsacRS.Phy

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