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Marine Habitat Classification

Description of biotope or habitat type

To understand more about what this page is describing, see How to use the classification. See also How to cite.

   High energy infralittoral rock

Physical habitat description

Salinity Full (30-35 ppt)
Wave exposure Extremely exposed, Very exposed, Exposed, Moderately exposed
Tidal streams Moderately strong (1-3 kn), Weak (>1 kn), Very weak (negligible)
Substratum Bedrock & boulders
Zone Infralittoral, Sublittoral fringe
Depth Band 0-5 m, 5-10 m, 10-20 m, Lower shore
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.HIR High energy 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.


Rocky habitats in the infralittoral zone subject to exposed to extremely exposed wave action or strong tidal streams. Typically the rock supports a community of kelp Laminaria hyperborea with foliose seaweeds and animals, the latter tending to become more prominent in areas of strongest water movement. The depth to which the kelp extends varies according to water clarity, exceptionally (e.g. St Kilda) reaching 45 m. The sublittoral fringe is characterised by dabberlocks Alaria esculenta. Surge gullies and caves typically lack kelp, and in reduced light conditions lack red seaweeds and are dominated by communities of sponges, ascidians, bryozoans, mussels and barnacles.


No situation data available.

Temporal variation

No temporal variation data available.

Characterising species

Characterising species data not applicable.

Similar biotopes or habitat types

Not applicable or unknown.

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