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Marine Habitat Classification

Description of biotope or habitat type

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   Fucus serratus on moderately exposed lower eulittoral rock

Physical habitat description

Salinity Full (30-35 ppt)
Wave exposure Moderately exposed, Sheltered
Tidal streams Moderately strong (1-3 kn), Weak (>1 kn)
Substratum Bedrock; boulders
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.MLR.BF.Fser <I>Fucus serratus</I> on moderately exposed lower eulittoral 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'

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


Lower eulittoral bedrock and stable boulders on moderately exposed to sheltered shores with a canopy of the wrack Fucus serratus and an associated fauna consisting of the limpet Patella vulgata, the barnacle Semibalanus balanoides, the whelk Nucella lapillus, the anemone Actinia equina and the sponge Halichondria panicea. Green seaweeds such as Ulva intestinalis and Ulva lactuca are usually present among/beneath the F. serratus canopy. Three variants of this biotope are described. These are: F. serratus with red seaweeds (Fser.R) and F. serratus with under-boulder communities (Fser.Bo) with sponges. Lastly, a F. serratus and piddocks community on soft rock has been identified (Fser.Pid). Dense F. serratus with fewer red seaweeds occurs on more sheltered shores (Fserr).


Above the F. serratus biotope on moderately exposed bedrock shores is the Fucus vesiculosus and/or S. balanoides and P. vulgata dominated biotopes (Sem; Sem.FvesR; FvesB). On more sheltered shores are biotopes dominated by the wracks F. vesiculosus and Ascophyllum nodosum (Fves; Asc.FS). On moderately exposed shores, the sublittoral fringe below Fser is dominated by the kelp Laminaria digitata and on vertical faces the kelp Alaria esculenta may be present (Ldig.LdigBo; Ala.Ldig). On more sheltered shores the kelp Saccharina latissima is found among the L. digitata (Lsac.Ldig; Lsac.Ft).

Temporal variation


Characterising species

Taxon Relative importance of taxon for defining this community (%) Typical abundance - SACFOR scale % of core records where taxon was recorded
Fucus serratus 20 Abundant 81-100%
Patella vulgata 8 Frequent 81-100%
Mastocarpus stellatus 7 Frequent 61-80%
Corallinaceae 6 Common 61-80%
Semibalanus balanoides 5 Frequent 61-80%
Osmundea pinnatifida 4 Frequent 61-80%
Chondrus crispus 3 Occasional 41-60%
Ulva intestinaloides 3 Occasional 41-60%
Halichondria panicea 3 Occasional 61-80%
Lomentaria articulata 3 Occasional 41-60%
Nucella lapillus 3 Occasional 61-80%
Corallina officinalis 2 Occasional 41-60%
Steromphala cineraria 2 Occasional 41-60%
Littorina littorea 2 Frequent 41-60%
Spirorbinae 2 Frequent 41-60%
Ulva lactuca 2 Occasional 21-40%
Actinia equina 1 Occasional 41-60%
Carcinus maenas 1 Occasional 41-60%

Similar biotopes or habitat types

Not applicable or unknown.

Classification history of this biotope or habitat type

Classification version Code
1995 LRK.FSE


LR.MLR.BF.Fser Fucus serratus on moderately exposed lower eulittoral rock, Knowe of Stenso, Eynhallow Sound. Sue Scott© JNCC
LR.MLR.BF.Fser Fucus serratus on moderately exposed lower eulittoral rock, Knowe of Stenso, Eynhallow Sound. Sue Scott© JNCC

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