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Marine Habitat Classification


Description of biotope or habitat type

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   Himanthalia elongata and red seaweeds on exposed to moderately exposed lower eulittoral rock


Habitat (physical) description

Salinity Full (30-35 ppt)
Wave exposure Exposed, Moderately exposed
Tidal streams
Substratum Bedrock
Zone Eulittoral - lower
Depth Band
Other Features himanthalia elongata may only be present as buttons in early spring

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.FR.Him <I>Himanthalia elongata</I> and red seaweeds on exposed to moderately exposed lower 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 lower eulittoral bedrock characterised by the wrack Himanthalia elongata with a dense turf of red seaweeds beneath. H. elongata may occur on tide-swept, sheltered shores in sea lochs (e.g. Loch Maddy). The wrack Fucus serratus is normally present as well. The predominant red seaweeds are usually Mastocarpus stellatus, Osmundea pinnatifida, Corallina officinalis and Palmaria palmata that tend to grow over a crust of the pink coralline algae Lithothamnion spp. Any patches between the algal turf may be colonised by barnacles Semibalanus balanoides, or Balanus perforatus in the south-west, and by the limpet Patella vulgata. Pits and crevices in the rock often provide a refuge for the whelk Nucella lapillus, the winkle Littorina spp. and small individuals of the mussel Mytilus edulis. Besides the dominant seaweeds there are a number of other red, brown and green seaweeds present. These include species such as the red seaweeds Dumontia contorta, Lomentaria articulata, Porphyra spp., the kelp Laminaria digitata and the green seaweeds Enteromorpha intestinalis, Ulva lactuca and Cladophora rupestris.

Situation

On some shores this biotope may occur as a distinct zone between a Fucus serratus and red algal turf (Fser.R) and the kelp Alaria esculenta and L. digitata community (Ala.Ldig). This biotope generally characterises those shores which are too exposed for F. serratus to form a dense canopy, often occurring as large patches within the F. serratus / red seaweed turf zone (Fser.R). Consequently, F. serratus plants frequently occur amongst the H. elongata and red seaweed turf.

Temporal variation

In early spring only characteristic H. elongata buttons are present, while the long erect parts of the thalli appears later in the season. This biotope may therefore appear very similar to Coff.Coff biotope in the spring and care should be taken when assessing these biotopes in early spring (See Similar biotopes).

Characterising Species

Taxon Relative importance of taxon for defining this community (%) Typical abundance - SACFOR scale % of core records where taxon was recorded
Semibalanus balanoides 10 Common 61-80 %
Patella vulgata 10 Common 61-80 %
Littorina 2 Frequent 21-40 %
Nucella lapillus 4 Occasional 61-80 %
Mytilus edulis 4 Frequent 41-60 %
Palmaria palmata 2 Occasional 41-60 %
Corallinaceae 3 Frequent 41-60 %
Corallina officinalis 9 Frequent 81-100 %
Lithothamnion 2 Frequent 21-40 %
Dumontia contorta 1 Occasional 41-60 %
Mastocarpus stellatus 10 Frequent 81-100 %
Lomentaria articulata 1 Occasional 41-60 %
Osmundea pinnatifida 5 Frequent 61-80 %
Laminaria digitata 2 Occasional 41-60 %
Fucus serratus 3 Frequent 41-60 %
Himanthalia elongata 18 Common 81-100 %
Enteromorpha intestinalis 2 Occasional 41-60 %
Ulva lactuca 1 Occasional 21-40 %
Cladophora rupestris 2 Frequent 41-60 %

Similar biotopes

LR.HLR.FR.Coff.Coff
Occurs in the lower eulittoral zone on exposed to moderately exposed shores. C. officinalis dominates instead of H. elongata and the limpet Patella ulyssiponensis can be common. The species richness of red seaweeds are higher, while kelp such as Alaria esculenta and wracks such as Fucus spp. are not as common if present at all.

LR.HLR.FR.Coff.Puly
Occurs on very exposed to exposed shores. The limpet P. ulyssiponensis and sponges such as Grantia compressa and Hymeniacidon perleve are present. Also the barnacles Chthamalus stellatus and Balanus perforatus are present and C. officinalis occur at higher abundance (Common). H. elongata can still be present at high abundance (Abundant. )

Biotope history

Classification Habitat code
6.95 LRK.HIM

Photos

LR.HLR.FR.Him Himanthalia elongata and red seaweeds on exposed to moderately exposed lower eulittoral rock, Eynhallow Island, Eynhallow Sound. Sue Scott © JNCC
LR.HLR.FR.Him Himanthalia elongata and red seaweeds on exposed to moderately exposed lower eulittoral rock, Eynhallow Island, Eynhallow Sound. Sue Scott © JNCC
LR.HLR.FR.Him Himanthalia elongata and red seaweeds on exposed to moderately exposed lower eulittoral rock, Quear of Eastafea, Rousay Sound. Sue Scott © JNCC
LR.HLR.FR.Him Himanthalia elongata and red seaweeds on exposed to moderately exposed lower eulittoral rock, Quear of Eastafea, Rousay Sound. Sue Scott © JNCC
LR.HLR.FR.Him Himanthalia elongata and red seaweeds on exposed to moderately exposed lower eulittoral rock, Quear of Eastafea, Rousay Sound. Sue Scott © JNCC
LR.HLR.FR.Him Himanthalia elongata and red seaweeds on exposed to moderately exposed lower eulittoral rock, Quear of Eastafea, Rousay Sound. Sue Scott © JNCC

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