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Marine Habitat Classification


Description of biotope or habitat type

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   Sparse Laminaria hyperborea and dense Paracentrotus lividus on exposed infralittoral limestone


Habitat (physical) description

Salinity Full (30-35 ppt)
Wave exposure Very exposed
Tidal streams Very weak (negligible)
Substratum Bedrock
Zone Infralittoral - upper
Depth Band 0-5 m, 5-10 m
Other Features Limestone platforms

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.HIR.KFaR.LhypPar Sparse <I>Laminaria hyperborea</I> and dense <I>Paracentrotus lividus</I> on exposed infralittoral limestone

  • 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

This biotope is known from only one location, the Aran Islands, Co. Galway. Here, a limestone platform between 3 m and 6 m of depth is dominated by a dense population of the urchin Paracentrotus lividus, which heavily graze and burrow into the soft limestone. So intense is the grazing pressure that the rock appears completely bare, except for a coralline algal crust and occasional Laminaria hyperborea and Saccorhiza polyschides. The anthozoans Sagartia elegans and Corynactis viridis are also present, though at low abundance. The grazed kelp also extends deeper to 20 to 25 m further offshore. (Only one CB record within this biotope).

Situation

This rare biotope has only been recorded from one location and the neighbouring biotopes were not fully surveyed. In deeper water (30-40m) there is PhaAxi.

Temporal variation

Unknown.

Characterising Species

Taxon Typical abundance - SACFOR scale % of core records where taxon was recorded
Cliona celata Occasional 81-100 %
Anemonia viridis Frequent 81-100 %
Urticina felina Rare 81-100 %
Sagartia elegans Frequent 81-100 %
Corynactis viridis Occasional 81-100 %
Paracentrotus lividus Super abundant 81-100 %
Laminaria hyperborea Occasional 81-100 %
Saccorhiza polyschides Occasional 81-100 %

Similar biotopes

Not applicable or unknown.

Biotope history

Classification Habitat code
96.7 EIR.LhypFa.Par

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