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LR.HLR.MusB.Sem.FvesR
Semibalanus balanoides, Fucus vesiculosus and red seaweeds on exposed to moderately exposed eulittoral rock

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Habitat (physical) description

Distribution

 Salinity: Full (30-35 ppt) 
 Wave exposure: Exposed, Moderately exposed 
 Tidal streams:  
 Substratum: Bedrock 
 Zone: Eulittoral - mid, Eulittoral - upper 
 Depth Band: Mid shore 
 Other Features: The growth formFucus vesiculosus f. linearis is often present 

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:
MLR.BPat.Fvesl - Version: 97.06

Distribution of habitat LR.HLR.MusB.Sem.FvesR  Semibalanus balanoides, Fucus vesiculosus and red seaweeds on exposed to moderately exposed eulittoral rock
Distribution of habitat LR.HLR.MusB.Sem.FvesR Semibalanus balanoides, Fucus vesiculosus and red seaweeds on exposed to moderately exposed eulittoral rock, 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

Exposed and moderately exposed upper and mid eulittoral bedrock characterised by the barnacle Semibalanus balanoides, the limpet Patella vulgata and the whelk Nucella lapillus with a sparse community of seaweeds. Turfs of the wrack Fucus vesiculosus can be present on the more horizontal parts of the shore though usually in low abundance (Occasional). Individuals of F. vesiculosus can lack the characteristic twin air bladders due to environmental stress (i.e. wave exposure). A sparse seaweed community consisting of foliose red seaweeds such as Osmundea pinnatifida and Mastocarpus stellatus are usually present along with the Corallina officinalis and the green seaweed Enteromorpha intestinalis. The algal community is usually restricted to fissures and cracks in the bedrock surface. Moist cracks and crevices also provide a refuge for small individuals of the mussel Mytilus edulis and the winkles Littorina saxatilis and Littorina littorea. These crevices can also be occupied by encrusting coralline algae and the anemone Actinia equina.

Situation

On exposed and moderately exposed shores Sem.FvesR is found below the black lichen Verrucaria maura and sparse barnacles biotope (Ver.B) and/or below the Chthamalus spp. and P. vulgata biotopes (Cht). Sem.FvesR is found above the biotope dominated by the wrack Himanthalia elongata (Him) or the red seaweed biotopes (Coff).

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) and a F. vesiculosus-dominated biotope (Fves). Individuals of F. vesiculosus growing in stressed environmental conditions (i.e. high wave exposure) do not always develop the characteristic twin air bladders.

Similar biotopes

LR.HLR.MusB.ChtOccurs in the upper eulittoral zone on slightly more exposed shores. It is dominated by the barnacles Chthamalus spp. and has a lower abundance of S. balanoides and N. lapillus. It lacks the sparse flora of seaweeds that are characteristic of Sem.FvesR.

Characterising Species

Taxa Frequency Typical Abundance % Contribution to similarity
Actinia equina O 4
Semibalanus balanoides A 27
Patella vulgata A 19
Littorina F 8
Littorina littorea O 2
Littorina saxatilis O 2
Nucella lapillus F 3
Mytilus edulis O 6
Corallinaceae O 4
Corallina officinalis O 2
Mastocarpus stellatus O 2
Osmundea pinnatifida O 3
Fucus vesiculosus O 4
Fucus vesiculosus O 4
Enteromorpha intestinalis O 4

Example photographs of biotope


 Semibalanus balanoides and Fucus vesiculosus mosaics, S of Rosemullion Head, Helford River., Keith Hiscock, © JNCC Semibalanus balanoides, Fucus vesiculosus and red seaweed mosaics, Tarn Bay, Ravenglass., Roger Covey, © JNCC
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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