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Marine Habitat Classification

Description of biotope or habitat type

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   Pelvetia canaliculata on sheltered variable salinity littoral fringe rock

Physical habitat description

Salinity Variable (18-35 ppt)
Wave exposure Very sheltered, Extremely sheltered
Tidal streams
Substratum Bedrock; boulders; cobbles
Zone Littoral fringe - lower
Depth Band 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.LLR.FVS.PelVS <I>Pelvetia canaliculata</I> on sheltered variable salinity littoral fringe 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'

Point data based on records in the UK Marine Recorder Snapshot.


Lower littoral fringe bedrock or stable boulders and mixed substrata on very sheltered to extremely sheltered variable salinity shores characterised by a dense cover of the wrack Pelvetia canaliculata, which often overgrows a crust of black lichens Verrucaria maura. The wrack Fucus spiralis can be present among the P. canaliculata. This biotope lacks the density of barnacles found among the P. canaliculata on more exposed shores though the occasional Semibalanus balanoides or Austrominius modestus can be found. The winkle Littorina saxatilis occurs, as do a variety of amphipods. The red alga Catenella caespitosa can be present in more shaded areas as well as the green seaweed Ulva intestinalis.


This biotope are found in the lower littoral fringe on sheltered shores below biotopes dominated by V. maura (Ver.Ver) and above biotopes dominated by F. spiralis (Fspi).

Temporal variation


Characterising species

Taxon Relative importance of taxon for defining this community (%) Typical abundance - SACFOR scale % of core records where taxon was recorded
Pelvetia canaliculata 54 Common 81-100%
Verrucaria maura 14 Common 61-80%
Littorina saxatilis 7 Frequent 41-60%
Catenella caespitosa 4 Frequent 41-60%
Austrominius modestus 3 Occasional 21-40%
Ulva intestinalis 3 Occasional 21-40%
Fucus spiralis 3 Occasional 41-60%
Semibalanus balanoides 2 Occasional 21-40%

Similar biotopes or habitat types

Occurs on shores with a higher wave exposure, and fully marine conditions. Barnacles such as Chthamalus montagui, Chthamalus stellatus or S. balanoides are always present and the limpet Patella vulgata can be present.

Occurs on more exposed shores and in fully marine conditions. The species composition is very similar. Barnacles such as S. balanoides can be present as well as the crab Carcinus maenas or the red alga Hildenbrandia rubra.

Classification history of this biotope or habitat type

Classification version Code
1997 (97.06) SLR.Pel (part)

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