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Marine Habitat Classification


Description of biotope or habitat type

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   Fucus vesiculosus on full salinity moderately exposed to sheltered mid eulittoral rock


Habitat (physical) description

Salinity Full (30-35 ppt)
Wave exposure Moderately exposed, Sheltered
Tidal streams
Substratum Bedrock; boulders
Zone Eulittoral - mid
Depth Band Mid shore
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.Fves.FS <I>Fucus vesiculosus</I> on full salinity moderately exposed to sheltered mid 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.

Description

Moderately exposed to sheltered mid eulittoral bedrock and large boulders characterised by a dense canopy of the wrack Fucus vesiculosus (Abundant to Superabundant). Beneath the seaweed canopy the rock surface has a sparse covering of the barnacle Semibalanus balanoides and the limpet Patella vulgata. The mussel Mytilus edulis is confined to pits and crevices. A variety of winkles including Littorina littorea, Littorina saxatilis and the whelk Nucella lapillus are found beneath the seaweeds, whilst Littorina obtusata/mariae graze on the fucoid fronds. The calcareous tube-forming polychaete Spirorbis spirorbis may also occur epiphytically on the fronds. In areas of localised shelter the wrack Ascophyllum nodosum may occur, though never at high abundance. Damp cracks and crevices often contain patches of the red seaweed Mastocarpus stellatus and even the wrack Fucus serratus may be present. The crab Carcinus maenas may be present in pools or among the boulders.

Situation

This biotope usually occurs between the wrack Fucus spiralis (Fspi) and the F. serratus (Fserr) zones; both of these fucoids may be present in this biotope, though never at high abundance (typically less than Frequent). In some sheltered areas F. vesiculosus forms a narrow zone above the A. nodosum zone (Asc). Where freshwater runoff occurs on more gradually sloping shores F. vesiculosus may be replaced by the wrack Fucus ceranoides (Fcer).

Temporal variation

On some shores, particularly those which are moderately exposed to wave action, temporal fluctuations in the abundance of limpets, barnacles and fucoid seaweeds may occur. As a result, over a number of years, a single shore may cycle between the barnacle-P. vulgata dominated biotope (Sem.FvesR), through this mosaic (FvesB) to a F. vesiculosus-dominated biotope (Fves).

Characterising Species

Taxon Relative importance of taxon for defining this community (%) Typical abundance - SACFOR scale % of core records where taxon was recorded
Semibalanus balanoides 13 Frequent 81-100 %
Carcinus maenas 1 Occasional 21-40 %
Patella vulgata 10 Frequent 61-80 %
Littorina littorea 3 Frequent 61-80 %
Littorina saxatilis 8 Occasional 21-40 %
Nucella lapillus 2 Occasional 41-60 %
Mytilus edulis 2 Occasional 21-40 %
Mastocarpus stellatus 2 Occasional 21-40 %
Ascophyllum nodosum 2 Occasional 21-40 %
Fucus serratus 1 Occasional 21-40 %
Fucus vesiculosus 35 Abundant 81-100 %
Enteromorpha intestinalis 4 Frequent 41-60 %

Similar biotopes

LR.HLR.MusB.Sem.FvesR
Occurs on more exposed shores or on steep or vertical faces. Sparse F. vesiculosus is present (Occasional) and the density of S. balanoides and P. vulgata is high (Abundant). More species of red seaweeds are present, while the wracks Ascophyllum nodosum and Fucus serratus are absent.

LR.MLR.BF.FvesB
Occurs on more exposed shores on bedrock and large boulders. F. vesiculosus is dominating, though less abundant (Common) and there is a higher diversity of red seaweeds. S. balanoides, P. vulgata and N. lapillus occurs more frequently and at higher abundance.

Biotope history

Classification Habitat code
6.95 LRK.FVES.LIT

Photos

LR.LLR.F.Fves.FS Fucus vesiculosus on full salinity moderately exposed to sheltered mid eulittoral rock, Eyemouth Harbour. David Connor © JNCC
LR.LLR.F.Fves.FS Fucus vesiculosus on full salinity moderately exposed to sheltered mid eulittoral rock, Eyemouth Harbour. David Connor © JNCC

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