Skip to Content

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.

   Fucus serratus on full salinity lower eulittoral mixed substrata

Physical habitat description

Salinity Full (30-35 ppt)
Wave exposure Sheltered, Very sheltered, Extremely sheltered
Tidal streams
Substratum Mixed cobbles, boulders and pebbles on sediment
Zone Eulittoral - lower
Depth Band
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 LR.LLR.F.Fserr.X <I>Fucus serratus</I> on full salinity lower eulittoral 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'

Point data based on records in the UK Marine Recorder Snapshot.


Sheltered to extremely sheltered full salinity lower eulittoral mixed substrata with dense stands of the wrack Fucus serratus. The crab Carcinus maenas and a large number of winkles such as Littorina littorea and Littorina obtusata/mariae can be found amongst the pebbles and cobbles as well as large individuals of the mussel Mytilus edulis, commonly occurring in clumps. On these mussels and on larger cobbles are the barnacle Semibalanus balanoides and the limpet Patella vulgata. Red algae such as coralline crusts including Lithothamnion spp. and the tube-forming polychaetes Pomatoceros triqueter and Spirorbis spp. can be found on cobbles and boulders. Spirorbis spp. can also be found on the F. serratus fronds. Sediment in the spaces between the loose substrata may support infauna including the polychaete Arenicola marina. The red seaweed Mastocarpus stellatus and the wrack Ascophyllum nodosum can occur in patches, while the green seaweeds Enteromorpha intestinalis and Cladophora spp. can be found among the mussels and underneath the F. serratus canopy.


Fserr.X occurs in the lower eulittoral below the biotopes dominated by the wrack Fucus vesiculosus and A. nodosum (Fves.X or Asc.X) on mixed substrata shores, or on sediment shores where mixed substrata occurs in discrete patches on the lower shore. Fserr.X occurs above biotopes dominated by the kelp Laminaria digitata or Laminaria saccharina (Ldig.Ldig; Lsac.Ldig; Lsac.Ft) depending on the substrata.

Temporal variation


Characterising species

Taxon Relative importance of taxon for defining this community (%) Typical abundance - SACFOR scale % of core records where taxon was recorded
Pomatoceros triqueter 3 Occasional 41-60 %
Spirorbis 7 Common 41-60 %
Semibalanus balanoides 1 Occasional 21-40 %
Carcinus maenas 1 Occasional 21-40 %
Patella vulgata 2 Occasional 21-40 %
Littorina littorea 12 Frequent 61-80 %
Littorina mariae 6 Common 41-60 %
Corallinaceae 2 Frequent 41-60 %
Lithothamnion 1 Frequent 21-40 %
Mastocarpus stellatus 5 Occasional 41-60 %
Ascophyllum nodosum 2 Occasional 21-40 %
Fucus serratus 34 Abundant 81-100 %
Fucus vesiculosus 5 Frequent 41-60 %
Enteromorpha intestinaloides 3 Frequent 41-60 %
Cladophora 1 Occasional 21-40 %

Similar biotopes or habitat types

Occurs on similar, but tide-swept substrata. It has a community dominated by filter-feeders such as the sponges Hymeniacidon perleve and the bryozoan Electra pilosa.

Occurs in full salinity on lower eulittoral bedrock and boulders, which are influenced by strong tidal streams. Filter-feeders such as hydroids Dynamena pumila or the bryozoans Alcyonidium spp. are present. Sponges such as Halichondria panicea and foliose red seaweeds such as Lomentaria articulata or Chondrus crispus are present.

Classification history of this biotope or habitat type

Classification version Code
97.06 SLR.Fser.X

Back to top