JNCC is a statutory adviser to UK Government and devolved administrations
  Home  >  Marine  >  Marine Habitats  >  Habitat  >  Biotope classification


LR.HLR.MusB
Mussel and/or barnacle communities

Full Hierarchy  >>  LR >>  LR.HLR >>  LR.HLR.MusB

Habitat (physical) description

Distribution

 Salinity: Full (30-35 ppt) 
 Wave exposure: Extremely exposed, Very exposed, 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.

Previous code

This biotope occurred in previous versions of the classification as:
ELR.BPat in part - Version: 97.06
ELR.MB in part - Version: 97.06
LRK.BP - Version: 6.95

Distribution of habitat LR.HLR.MusB  Mussel and/or barnacle communities
Distribution of habitat LR.HLR.MusB Mussel and/or barnacle communities, based on records on the UK Marine Recorder database and EUSeaMap. Red dots represent records on which the biotope is based. Blue dots show other certain records, black dots show records tentatively assigned to this biotope. Yellow areas show level 2 and 3 sublittoral and deep-sea habitats prediced by EUSeaMap within UK waters.

Biotope description

Communities on very exposed to moderately exposed upper and mid eulittoral bedrock and boulders dominated by the mussel Mytilus edulis (MytB), barnacles Chthamalus spp. and/or Semibalanus balanoides and limpets Patella spp. (Cht, Sem). Several variants are identified. Some shores are characterised by dense bands of the barnacle Semibalanus balanoides and the limpet Patella vulgata (Sem). The barnacles may be covered by Porphyra umbilicalis on the upper shore of exposed sites. Cracks and crevices in the rock provide a refuge for small individuals of the mussel M. edulis, winkles Littorina saxatilis and the whelk Nucella lapillus. Red seaweeds also frequently occupy damp crevices, particularly Ceramium shuttleworthianum, Corallina officinalis, Osmundea pinnatifida and encrusting coralline algae, but the non-vesiculate form of the wrack Fucus vesiculosus might be present (Sem.FvesR). Large numbers of the winkle Littorina littorea often dominate fields of large boulders or shores with a more mixed substratum (Sem.LlitX). There is much regional variation affecting the zonation of barnacles in the British Isles. In the north-west C. montagui and/or C. stellatus can form a distinct band above S. balanoides. In the south-west C. montagui and/or C. stellatus can be the dominant barnacles throughout the eulittoral zone (Cht.Cht). On the east coasts S. balanoides is able to extend to the upper shore due to the absence of Chthamalus spp. and thereby any competition. The lichen Lichina pygmaea may be prominent, especially in the south, where it can form distinct patches or even a separate zone among the Chthamalus spp. (Cht.Lpyg). In areas of soft rock (e.g. shales), the barnacles may be scarce or absent and the rock dominated by P. vulgata.

Situation

This biotope complex is found in the mid to upper eulittoral on very to moderately exposed shores below the lichen dominated biotopes (Lic) and is typically characterised by patches of mussels M. edulis interspersed with barnacles. Below the MusB biotopes is a community dominated by the wrack Himanthalia elongata and red seaweeds such as C. officinalis, Mastocarpus stellatus and O. pinnatifida (FR). With decreasing wave exposure F. vesiculosus is able to survive, gradually replacing the barnacles and P. vulgata biotope (FvesB). On such moderately exposed shores MusB biotopes may occur on steep and vertical faces, while fucoids dominate the flatter areas (Sem.FvesR, FvesB).

Temporal variation

No temporal variation data available.

Similar biotopes

Not applicable or unknown.

Characterising Species

Taxa Frequency Typical Abundance % Contribution to similarity
Actinia equina O 1
Chthamalus montagui R 1
Semibalanus balanoides C 33
Patella vulgata C 21
Littorina C 1
Littorina littorea F 6
Littorina saxatilis F 2
Nucella lapillus F 5
Mytilus edulis F 15
Porphyra umbilicalis F 1
Palmaria palmata O 1
Corallina officinalis O 1
Mastocarpus stellatus O 1

Example photographs of biotope


Midshore community, S Point En nan Gobhar, Loch Ailort, Keith Hiscock, © JNCC
Click on an image for a larger view


Version 15.03 of the classification adds a deep-sea section to version 04.05; therefore superseding version 04.05, 97.06 and 03.02.

This online classification should be cited as:

JNCC (2015) The Marine Habitat Classification for Britain and Ireland Version 15.03 [Online]. [Date accessed]. Available from: jncc.defra.gov.uk/MarineHabitatClassification

Information from the shallower section (up to sublittoral sediment, taken from Version 04.05) be cited as the report accompanying Version 04.05, as follows:

CONNOR, D.W., J.H. ALLEN, N.GOLDING, K.L.HOWELL, L.M. LIEBERKNECHT, K.O. NORTHEN AND J.B. REKER (2004) The Marine Habitat Classification for Britain and Ireland Version 04.05. In: JNCC (2015) The Marine Habitat Classification for Britain and Ireland Version 15.03 [Online]. [Date accessed].
Available from: jncc.defra.gov.uk/MarineHabitatClassification
ISBN 1 861 07561 8


Information from the deep-sea section (added in March 2015) should be cited as the report accompanying the deep-sea section, as follows:

PARRY, M.E.V., K.L. HOWELL, B.E. NARAYANASWAMY, B.J. BETT, D.O.B. JONES, D.J. HUGHES, N. PIECHAUD, T.D. NICKELL, H. ELLWOOD, N. ASKEW, C. JENKINS and E. MANCA (2015) A Deep-sea Section for the Marine Habitat Classification of Britain and Ireland. JNCC report 530. In: JNCC (2015) The Marine Habitat Classification for Britain and Ireland Version 15.03 [Online]. [Date accessed].
Available from: jncc.defra.gov.uk/MarineHabitatClassification
ISSN 0963 8901