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Marine Habitat Classification


Description of biotope or habitat type

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   Fucus spiralis on exposed to moderately exposed upper eulittoral rock


Habitat (physical) description

Salinity Full (30-35 ppt)
Wave exposure Exposed, Moderately exposed
Tidal streams
Substratum Bedrock; boulders; cobbles
Zone Eulittoral - upper
Depth Band
Other Features Also on steep/vertical sheltered bedrock

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.FspiB <I>Fucus spiralis</I> on exposed to moderately exposed upper 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

Exposed to moderately exposed upper eulittoral bedrock characterised by a band of the spiral wrack Fucus spiralis overlying the black lichen Verrucaria maura and the olive green lichen Verrucaria mucosa. Underneath the fronds of F. spiralis is a community consisting of the limpet Patella vulgata, the winkles Littorina saxatilis and Littorina littorea, the mussel Mytilus edulis and the barnacle Semibalanus balanoides. The whelk Nucella lapillus can be found in cracks and crevices preying on the mussels and barnacles. During the summer months ephemeral green seaweeds such as Enteromorpha intestinalis can be common. The insect Anurida maritima can be present in this zone taking shelter in cracks and crevices when the tide comes in.

Situation

This zone usually lies below a zone dominated by the wrack Pelvetia canaliculata (PelB), but occasional clumps of P. canaliculata may be present (usually less than common) amongst the F. spiralis. FspiB occurs above the wrack Fucus vesiculosus (FvesB) zones. Vertical surfaces in this zone, especially on moderately exposed shores, often lack the fucoids and are characterised by a barnacle-limpet dominated community (Sem).

Temporal variation

Unknown.

Characterising Species

Taxon Relative importance of taxon for defining this community (%) Typical abundance - SACFOR scale % of core records where taxon was recorded
Semibalanus balanoides 29 Abundant 81-100 %
Anurida maritima 2 Occasional 41-60 %
Patella vulgata 8 Frequent 61-80 %
Littorina littorea 5 Frequent 41-60 %
Littorina saxatilis 9 Frequent 61-80 %
Nucella lapillus 2 Occasional 41-60 %
Mytilus edulis 5 Occasional 61-80 %
Fucus spiralis 24 Common 81-100 %
Enteromorpha intestinalis 2 Occasional 41-60 %
Verrucaria maura 2 Frequent 21-40 %
Verrucaria mucosa 2 Occasional 21-40 %

Similar biotopes

LR.LLR.FVS.FspiVS
Occurs in sheltered areas with variable salinity. The species diversity is lower and species such as P. vulgata and M. edulis usually absent as well as the lichen Verrucaria maura. The barnacle Elminius modestus can be present.

LR.LLR.F.Fspi.X
Occurs on mixed substrata and in sheltered areas. It has a similar species composition, although amphipods, the crab Carcinus maenas and the whelk Nucella lapillus may occur underneath and/or among the boulders and cobbles. S. balanoides is not occurring in same high abundance (Occasional). In sheltered areas (behind boulders) A. nodosum can be found.

Biotope history

Classification Habitat code
97.06 SLR.Fspi in part

Photos

LR.MLR.BF.FspiB Fucus spiralis on exposed to moderately exposed upper eulittoral rock, SE Els Ness, South Sanday. Sue Scott © JNCC
LR.MLR.BF.FspiB Fucus spiralis on exposed to moderately exposed upper eulittoral rock, SE Els Ness, South Sanday. Sue Scott © JNCC

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