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Marine Habitat Classification


Description of biotope or habitat type

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   Laminaria hyperborea forest, foliose red seaweeds and a diverse fauna on tide-swept upper infralittoral rock


Habitat (physical) description

Salinity Full (30-35 ppt)
Wave exposure Extremely exposed, Very exposed, Exposed, Moderately exposed
Tidal streams Strong (3-6 kn), Moderately strong (1-3 kn)
Substratum Bedrock; boulders
Zone Infralittoral - upper
Depth Band 0-5 m, 5-10 m, 10-20 m
Other Features

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 IR.MIR.KR.LhypT.Ft <I>Laminaria hyperborea</I> forest, foliose red seaweeds and a diverse fauna on tide-swept upper infralittoral 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'
  • Predicted extent of the level 3 (for sublittoral rock & deep sea) or 4 (for sublittoral sediment) habitat

Point data based on records in the UK Marine Recorder Snapshot. Predicted habitat extent is from UKSeaMap.

Description

Exposed to moderately exposed, tide-swept bedrock and boulders, with dense Laminaria hyperborea forest, characterised by a rich under-storey and stipe flora of foliose seaweeds. The kelp stipes support epiphytes such as Callophyllis laciniata, Corallina officinalis, Cryptopleura ramosa, Membranoptera alata, and Phycodrys rubens. At some sites, instead of being covered by red seaweeds, the kelp stipes are heavily encrusted by the ascidians Botryllus schlosseri and in the south-west Distomus variolosus. Epilithic seaweeds (Dilsea carnosa, Hypoglossum hypoglossoides, Delesseria sanguinea, Plocamium cartilagineum, Brongniartella byssoides, and Dictyota dichotoma ) and crustose seaweeds commonly occur beneath the kelp. The kelp fronds are often covered with growth of the hydroid Obelia geniculata or the bryozoan Membranipora membranacea. Although these species are also found in most kelp forests, in this biotope they are particularly dense. On the rock surface, a rich fauna comprising of the sponges Pachymatisma johnstonia, Halichondria panicea, Esperiopsis fucorum and Dysidea fragilis, anthozoans such as Urticina felina, Alcyonium digitatum and Caryophilia smithii, the barnacle Balanus crenatus, colonial ascidians such as Clavelina lepadiformis, and the gastropods Calliostoma zizyphinum and Gibbula cineraria, occur. Also found on the rock is the echinoderm Asterias rubens and the crab Cancer pagurus.

Situation

This biotope occurs below Alaria esculenta (Ala) at exposed sites or L. digitata (Ldig.Ldig) at moderately exposed locations. With increasing depth the kelp density diminishes to become tide-swept kelp park (LhypT.Pk).

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
Pachymatisma johnstonia 2 Occasional 41-60 %
Halichondria panicea 1 Occasional 21-40 %
Esperiopsis fucorum 1 Occasional 21-40 %
Dysidea fragilis 2 Occasional 21-40 %
Obelia geniculata 1 Frequent 41-60 %
Alcyonium digitatum 2 Occasional 41-60 %
Urticina felina 1 Occasional 41-60 %
Caryophyllia smithii 1 Occasional 21-40 %
Balanus crenatus 1 Occasional 21-40 %
Cancer pagurus 1 41-60 %
Membranipora membranacea 2 41-60 %
Asterias rubens 3 61-80 %
Clavelina lepadiformis 2 Occasional 41-60 %
Botryllus schlosseri 3 Occasional 41-60 %
Corallinaceae 3 Frequent 61-80 %
Corallina officinalis 1 Occasional 21-40 %
Dilsea carnosa 2 Occasional 41-60 %
Callophyllis laciniata 2 Occasional 41-60 %
Plocamium cartilagineum 6 Frequent 61-80 %
Cryptopleura ramosa 3 Frequent 61-80 %
Delesseria sanguinea 4 Frequent 61-80 %
Hypoglossum hypoglossoides 1 Frequent 21-40 %
Membranoptera alata 1 Occasional 41-60 %
Phycodrys rubens 3 Frequent 61-80 %
Brongniartella byssoides 2 Occasional 41-60 %
Dictyota dichotoma 2 Frequent 41-60 %
Laminaria hyperborea 10 Abundant 81-100 %

Similar biotopes

IR.HIR.KFaR.LhypFa
On very exposed coasts subject to weaker tidal currents. The fauna turf is characterised by a higher abundance of anthozoans such as Corynactis viridis and Sargartia elegans, but topshells such C. zizyphinum and Gibbula cineraria are also common. Red seaweeds are present but less dense than LhypT.Ft.

IR.MIR.KR.LhypT.Pk
Found in similar tide-swept conditions, often forming a zone below the kelp forest (LhypT.Ft) in deeper water where the kelp is less dense and more upper circalittoral species occurs.

IR.MIR.KR.Lhyp.Ft
Found in areas similar wave exposure but not subject to accelerated tidal currents and lacks therefore a prominent filter feeder community. The large variety of sponges such as H. panicea and Esperiopsis fucorum, the bryozoans A. diaphanum and Flustra foliacea and the barnacle Balanus balanus are not found in great abundance in the kelp forest.

IR.MIR.KR.LhypTX.Ft
Found in similar tide swept conditions, but on mixed substrata.

Photos

IR.MIR.KR.LhypT.Ft Laminaria hyperborea forest, foliose red seaweeds and a diverse fauna on tide-swept upper infralittoral rock, Pinnacle in mouth of Loch Craignish. Christine Howson © JNCC
IR.MIR.KR.LhypT.Ft Laminaria hyperborea forest, foliose red seaweeds and a diverse fauna on tide-swept upper infralittoral rock, Pinnacle in mouth of Loch Craignish. Christine Howson © JNCC
IR.MIR.KR.LhypT.Ft Laminaria hyperborea forest, foliose red seaweeds and a diverse fauna on tide-swept upper infralittoral rock, Out Stack South, Shetland. Sue Hiscock © JNCC
IR.MIR.KR.LhypT.Ft Laminaria hyperborea forest, foliose red seaweeds and a diverse fauna on tide-swept upper infralittoral rock, Out Stack South, Shetland. Sue Hiscock © JNCC
IR.MIR.KR.LhypT.Ft Laminaria hyperborea forest, foliose red seaweeds and a diverse fauna on tide-swept upper infralittoral rock, Unspecified location. ANON © JNCC
IR.MIR.KR.LhypT.Ft Laminaria hyperborea forest, foliose red seaweeds and a diverse fauna on tide-swept upper infralittoral rock, Unspecified location. ANON © JNCC

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