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Marine Habitat Classification

Description of biotope or habitat type

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   Barnacles and fucoids on moderately exposed shores

Physical habitat description

Salinity Full (30-35 ppt)
Wave exposure Moderately exposed
Tidal streams
Substratum Bedrock; boulders
Zone Eulittoral
Depth Band Lower shore, Mid shore, Upper 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 LR.MLR.BF Barnacles and fucoids on moderately exposed shores

  • 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.


Moderately exposed rocky shores characterised by a mosaic of fucoids and barnacles on bedrock and boulders, where the extent of the fucoid cover is typically less than the blanket cover associated with sheltered shores. Other species are normally present as well in this habtat including the winkle Littorina littorea, the whelk Nucella lapillus and the red seaweed Mastocarpus stellatus. Beneath the band of yellow and grey lichens at the top of the shore is a zone dominated by the wrack Pelvetia canaliculata, scattered barnacles, while the black lichen Verrucaria maura covers the rock surface (PelB). Below, on the mid shore the wrack Fucus vesiculosus generally forms a mosaic with the barnacle Semibalanus balanoides and the limpet Patella vulgata (FvesB). Finally, the wrack Fucus serratus, dominates the lower shore, while a variety of red seaweeds can be found underneath the F. serratus canopy (Fser). A number of variants have been described: lower shore bedrock and boulders characterised by mosaics of F. serratus and turf-forming red seaweeds (Fser.R); where the density of F. serratus is greater (typically Common - Superabundant) and the abundance of red seaweeds less Fserr.FS should be recorded. The presence of boulders and cobbles on the shore can increase the micro-habitat diversity, which often results in a greater species richness. Although the upper surface of the boulders may bear very similar communities to Fserr.FS there is often an increase in fauna (crabs, tube-forming polychaetes, sponges and bryozoans) and Fser.Bo should be recorded. Sand-influenced exposed to moderately exposed lower shore rock can be characterised by dense mats of Rhodothamniella floridula (Rho).


Mid and lower eulittoral moderately exposed bedrock with a lichen zone above and a kelp dominated community below in the sublittoral zone.

Temporal variation

No temporal variation data available.

Characterising species

Taxon Typical abundance - SACFOR scale % of core records where taxon was recorded
Fucus serratus Abundant 61-80%
Fucus vesiculosus Frequent 21-40%
Littorina littorea Frequent 21-40%
Mastocarpus stellatus Frequent 41-60%
Nucella lapillus Occasional 41-60%
Patella vulgata Frequent 61-80%
Pelvetia canaliculata Common 21-40%
Semibalanus balanoides Frequent 61-80%
Ulva intestinalis Occasional 41-60%
Verrucaria maura Common 21-40%

Similar biotopes or habitat types

Not applicable or unknown.

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