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Marine Habitat Classification


Description of biotope or habitat type

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   Semibalanus balanoides on exposed to moderately exposed or vertical sheltered eulittoral rock


Habitat (physical) description

Salinity Full (30-35 ppt)
Wave exposure Exposed, Moderately exposed
Tidal streams
Substratum Bedrock; large boulders
Zone Eulittoral - mid, Eulittoral - upper
Depth Band Mid shore, Upper shore
Other Features Also on sheltered vertical 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.HLR.MusB.Sem <I>Semibalanus balanoides</I> on exposed to moderately exposed or vertical sheltered 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 mid to upper eulittoral bedrock and large boulders characterised by dense barnacles Semibalanus balanoides and the limpet Patella vulgata. The community has a relatively low diversity of species though occasional cracks and crevices in the rock can provide a refuge for small individuals of the mussel Mytilus edulis, the winkle Littorina saxatilis and the whelk Nucella lapillus. Seaweeds are usually not found in high numbers though fissures and crevices in the bedrock can hold a sparse algal community including the green seaweed Enteromorpha intestinalis. On some shores the olive green lichen Verrucaria mucosa can be present in some abundance (Frequent). Three variants have been described: A S. balanoides and P. vulgata dominated community on bedrock (Sem.Sem); S. balanoides and sparse Fucus vesioculosus and red seaweeds (Sem.FvesR); and barnacles and L. littorea eulittoral boulders and cobbles (Sem.LlitX).

Situation

On very exposed to exposed shores Chthamalus spp. (see Cht for geographical variation) often forms a distinct white band above a darker band of S. balanoides in the mid eulittoral zone. Alternatively, the black lichen Verrucaria maura dominated biotopes (Ver.Ver or Ver.B) may be found above Sem. In the lower eulittoral and the sublittoral fringe a community dominated by the wrack Himanthalia elongata and various red seaweeds such as Corallina officinalis, Mastocarpus stellatus and Osmundea pinnatifida (Him; Coff; Osm) often occurs. Sem may also occur on steep and vertical faces on more sheltered shores, while fucoids dominate the flatter areas (FvesB; Sem.FvesR).

Temporal variation

Periods with little scour or calmer weather can allow a seaweed community to develop, creating a more diverse biotope (i.e. Fves or FvesB). This is a dynamic process, which will change individual sites over time. More information is required to determine the exact nature of this process.

Characterising Species

Taxon Relative importance of taxon for defining this community (%) Typical abundance - SACFOR scale % of core records where taxon was recorded
Semibalanus balanoides 38 Abundant 81-100 %
Patella vulgata 18 Common 61-80 %
Littorina 8 Common 41-60 %
Littorina saxatilis 5 Frequent 21-40 %
Nucella lapillus 5 Frequent 41-60 %
Mytilus edulis 9 Occasional 61-80 %
Enteromorpha intestinalis 2 Occasional 21-40 %
Verrucaria mucosa 2 Frequent 21-40 %

Similar biotopes

Not applicable or unknown.

Biotope history

Classification Habitat code
97.06 ELR.BPat.Sem

Photos

LR.HLR.MUSB.Sem Semibalanus balanoides on exposed to moderately exposed or vertical sheltered eulittoral rock, Between E & W Wideopen. Teresa Bennett © JNCC
LR.HLR.MUSB.Sem Semibalanus balanoides on exposed to moderately exposed or vertical sheltered eulittoral rock, Between E & W Wideopen. Teresa Bennett © JNCC
LR.HLR.MUSB.Sem Semibalanus balanoides on exposed to moderately exposed or vertical sheltered eulittoral rock, Ardwall Island South, N Solway. David Mills © JNCC
LR.HLR.MUSB.Sem Semibalanus balanoides on exposed to moderately exposed or vertical sheltered eulittoral rock, Ardwall Island South, N Solway. David Mills © JNCC
LR.HLR.MUSB.Sem Semibalanus balanoides on exposed to moderately exposed or vertical sheltered eulittoral rock, Great Carr, North Berwick. David Connor © JNCC
LR.HLR.MUSB.Sem Semibalanus balanoides on exposed to moderately exposed or vertical sheltered eulittoral rock, Great Carr, North Berwick. David Connor © JNCC

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