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Marine Habitat Classification


Description of biotope or habitat type

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   Porphyra purpurea and Enteromorpha spp. on sand-scoured mid or lower eulittoral rock


Habitat (physical) description

Salinity Full (30-35 ppt), Variable (18-35 ppt)
Wave exposure Exposed, Moderately exposed
Tidal streams
Substratum Bedrock; boulders
Zone Eulittoral
Depth Band Mid shore
Other Features Sand-scour

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.FLR.Eph.EntPor <I>Porphyra purpurea</I> and <I>Enteromorpha</I> spp. on sand-scoured mid or lower eulittoral 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.

Description

Exposed and moderately exposed mid-shore bedrock and boulders occurring adjacent to areas of sand which significantly affects the rock. As a consequence of sand-abrasion, wracks such as Fucus vesiculosus or Fucus spiralis are scarce and the community is typically dominated by ephemeral red or green seaweeds, particularly the foliose red seaweed Porphyra purpurea and green seaweeds such as Enteromorpha spp. Under the blanket of ephemeral seaweeds, the barnacles Semibalanus balanoides or Elminius modestus and the limpet Patella vulgata may occur in the less scoured areas, along with the occasional winkles Littorina littorea and Littorina saxatilis. Few other species are present.

Situation

Usually found below the species impoverished biotope dominated by Enteromorpha spp. (Ent) and above the F. spiralis zone (Fspi). It may replace the zone dominated by the wrack Pelvetia canaliculata (PelB). In areas where sand abrasion is less severe, the sand-binding red alga Rhodothamniella floridula occurs with other sand-tolerant seaweeds and the wrack Fucus serratus (Rho), along with the mussel Mytilus edulis.

Temporal variation

Seasonal fluctuations in the abundance of the Enteromorpha spp. and the P. purpurea will occur, especially as a result of storm action.

Characterising Species

Taxon Relative importance of taxon for defining this community (%) Typical abundance - SACFOR scale % of core records where taxon was recorded
Elminius modestus 2 Occasional 21-40 %
Semibalanus balanoides 6 Occasional 41-60 %
Patella vulgata 3 Occasional 21-40 %
Littorina littorea 7 Occasional 41-60 %
Littorina saxatilis 3 Occasional 21-40 %
Mytilus edulis 2 Frequent 21-40 %
Porphyra 2 Frequent 21-40 %
Porphyra purpurea 11 Frequent 41-60 %
Fucus vesiculosus 3 Occasional 21-40 %
Enteromorpha 48 Abundant 41-60 %
Enteromorpha intestinalis 3 21-40 %
Enteromorpha prolifera 2 21-40 %
Ulva lactuca 2 Frequent 21-40 %

Similar biotopes

LR.FLR.Eph.Ent
Occurs from the mid eulittoral to the supralittoral zone, often in freshwater influenced habitats. It has a lower species richness and the red seaweed P. purpurea and the wracks F. spiralis or F. vesiculosus are usually not present. The winkle L. littorea is also absent.

LR.FLR.Eph.EphX
Occurs in more estuarine conditions and on mixed substrata. A very similar biotope.

Biotope history

Classification Habitat code
6.95 LRK.EPH
96.7 MLR.Eph.Por

Photos

LR.FLR.EPH.EntPor Porphyra purpurea and Enteromorpha spp. on sand-scoured mid or lower eulittoral rock, Pentine Point East, Newquay. David Connor © JNCC
LR.FLR.EPH.EntPor Porphyra purpurea and Enteromorpha spp. on sand-scoured mid or lower eulittoral rock, Pentine Point East, Newquay. David Connor © JNCC
LR.FLR.EPH.EntPor Porphyra purpurea and Enteromorpha spp. on sand-scoured mid or lower eulittoral rock, Shakespeare Cliff, Dover. David George © JNCC
LR.FLR.EPH.EntPor Porphyra purpurea and Enteromorpha spp. on sand-scoured mid or lower eulittoral rock, Shakespeare Cliff, Dover. David George © JNCC
LR.FLR.EPH.EntPor Porphyra purpurea and Enteromorpha spp. on sand-scoured mid or lower eulittoral rock, Great Carr, North Berwick. David Connor © JNCC
LR.FLR.EPH.EntPor Porphyra purpurea and Enteromorpha spp. on sand-scoured mid or lower eulittoral rock, Great Carr, North Berwick. David Connor © JNCC

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