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Marine Habitat Classification


Description of biotope or habitat type

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   Mixed Laminaria hyperborea and Laminaria saccharina on sheltered infralittoral rock


Habitat (physical) description

Salinity Full (30-35 ppt)
Wave exposure Sheltered, Extremely sheltered
Tidal streams Weak (>1 kn), Very weak (negligible)
Substratum Bedrock; boulders
Zone Infralittoral
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.LIR.K.LhypLsac Mixed <I>Laminaria hyperborea</I> and <I>Laminaria saccharina</I> on sheltered 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

Mixed Laminaria hyperborea and Laminaria saccharina on bedrock and boulders in sheltered infralittoral habitats. Typically subject to weak tidal streams and rather silty conditions. Beneath the kelp is an associated under-storey flora of foliose red seaweeds including Plocamium cartilagineum, Cryptopleura ramosa and Callophyllis laciniata as well as the brown seaweeds Dictyota dichotoma, Cutleria multifida and Desmarestia aculeata. The stipes of L. hyperborea may be densely covered with red seaweeds such as Phycodrys rubens and Delesseria sanguinea as well as the solitary ascidian Clavelina lepadiformis and the featherstar Antedon bifida. The fronds are often epiphytised by the hydroid Obelia geniculata and the bryozoan Membranipora membranacea. Beneath the kelp canopy, the faunal component is generally less diverse than the more exposed kelp forests, dominated by the echinoderms Echinus esculentus and Asterias rubens, but the tops shells Gibbula cineraria and Calliostoma zizyphinum can be common as well. The crab Necora puber and the brittlestar Ophiothrix fragilis can be found in cracks and crevices, while the tube-building polychaete Pomatoceros triqueter and coralline crusts are present on the rock surface. Although there is a reduced number of species by comparison to the more exposed L. hyperborea forests (Lhyp.Ft), there are considerably more algae species than occur in the more sheltered L. saccharina forests (Lsac.Ft). This biotope is predominately found in the shelter of fjordic sealochs in Scotland. Where it does occur in south-west Britain the mixed kelp forest may also include the southern kelp Laminaria ochroleuca. Three variants has been described: The kelp forest in the upper infralittoral (LhypLsac.Ft), grading to a kelp park with increasing depth (LhypLsac.Pk) as well as a grazed variant (LhypLsac.Gz).

Situation

No situation data available.

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
Obelia geniculata 2 Occasional 41-60 %
Pomatoceros triqueter 6 Frequent 61-80 %
Necora puber 1 Occasional 41-60 %
Gibbula cineraria 5 Frequent 61-80 %
Calliostoma zizyphinum 2 Occasional 41-60 %
Membranipora membranacea 1 Occasional 21-40 %
Asterias rubens 4 Occasional 61-80 %
Ophiothrix fragilis 1 Occasional 21-40 %
Echinus esculentus 5 Occasional 61-80 %
Clavelina lepadiformis 2 Occasional 41-60 %
Corallinaceae 6 Common 61-80 %
Callophyllis laciniata 1 Occasional 41-60 %
Plocamium cartilagineum 3 Occasional 41-60 %
Cryptopleura ramosa 1 Occasional 41-60 %
Delesseria sanguinea 3 Occasional 41-60 %
Phycodrys rubens 3 Frequent 41-60 %
Cutleria multifida 1 Frequent 21-40 %
Dictyota dichotoma 1 Occasional 41-60 %
Desmarestia aculeata 1 Occasional 21-40 %
Laminaria hyperborea 15 Common 81-100 %
Laminaria saccharina 10 Frequent 81-100 %

Similar biotopes

Not applicable or unknown.


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