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Marine Habitat Classification


Description of biotope or habitat type

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   Mytilus edulis and Fucus vesiculosus on moderately exposed mid eulittoral rock


Habitat (physical) description

Salinity Full (30-35 ppt)
Wave exposure Exposed, Moderately exposed
Tidal streams
Substratum Bedrock; large boulders
Zone Eulittoral - mid
Depth Band Mid shore
Other Features Silted habitat

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.MusF.MytFves <I>Mytilus edulis</I> and <I>Fucus vesiculosus</I> on moderately exposed 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

Mid eulittoral exposed to moderately exposed bedrock, often with nearby sediment, covered by a dense band or large patches of the mussel Mytilus edulis. The community often supports scattered Fucus vesiculosus and occasional foliose red seaweeds such as Porphyra umbilicalis, Osmundea pinnatifida, Mastocarpus stellatus, Palmaria palmata or the calcareous algae Corallina officinalis . The ephemeral green seaweeds Enteromorpha intestinalis and Ulva lactuca commonly occur on the shells of the mussels. The barnacle Semibalanus balanoides is common on both the mussel valves and on patches of bare rock, where the limpet Patella vulgata also can be found. The whelk Nucella lapillus and the winkle Littorina littorea can be found within the mussel bed.

Situation

Above this biotope is a M. edulis and S. balanoides dominated biotope (Sem) or a F. vesiculosus dominated biotope (FvesB). In the lower eulittoral zone below MytFves is a biotope dominated by the wrack Fucus serratus, M. edulis and a higher diversity of red seaweeds (MytFR; Fser.R).

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 15 Common 81-100 %
Patella vulgata 11 Common 81-100 %
Littorina littorea 5 Frequent 41-60 %
Nucella lapillus 9 Occasional 81-100 %
Mytilus edulis 26 Abundant 81-100 %
Porphyra umbilicalis 3 Occasional 41-60 %
Palmaria palmata 1 Common 21-40 %
Corallina officinalis 1 Occasional 41-60 %
Mastocarpus stellatus 1 Occasional 21-40 %
Osmundea pinnatifida 1 Occasional 41-60 %
Fucus vesiculosus 10 Common 81-100 %
Enteromorpha intestinalis 3 Frequent 61-80 %
Ulva lactuca 2 Occasional 21-40 %

Similar biotopes

LR.HLR.MusB.MytB
Occurs on more exposed shores. Has lower species richness with the notable absence of species such as F. vesiculosus and L. littorea.

LR.MLR.MusF.MytFR
Occurs in similar wave exposure but in the lower eulittoral zone. F. serratus dominates and F. vesiculosus is usually absent. Kelp such as Laminaria digitata can be present and usually the abundance of the red seaweeds is higher.

LS.LBR.LMus.Myt
Occurs on mixed substrata, typically in more sheltered conditions. F. vesiculosus can be present at low abundance (Occasional) while L. littorea occurs in higher density. Red seaweeds are scarce and the barnacle Elminius modestus can be present.

Biotope history

Classification Habitat code
96.7 MLR.Myt.Fves
97.06 MLR.MytFves

Photos

LR.MLR.MUSF.MytFves Mytilus edulis and Fucus vesiculosus on moderately exposed mid eulittoral rock, Pentine Point East, Newquay. David Connor © JNCC
LR.MLR.MUSF.MytFves Mytilus edulis and Fucus vesiculosus on moderately exposed mid eulittoral rock, Pentine Point East, Newquay. David Connor © JNCC

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