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Marine Habitat Classification


Description of biotope or habitat type

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   Hydroids, ephemeral seaweeds and Littorina littorea in shallow eulittoral mixed substrata pools


Habitat (physical) description

Salinity Full (30-35 ppt)
Wave exposure Moderately exposed, Sheltered
Tidal streams
Substratum Cobbles; pebbles; gravel; sand
Zone Eulittoral
Depth Band Mid shore
Other Features Rockpool or standing water

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.Rkp.H Hydroids, ephemeral seaweeds and <I>Littorina littorea</I> in shallow eulittoral mixed substrata pools

  • 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

Shallow pools on mixed cobbles, pebbles, gravel and sand characterised by abundant hydroids. Species present may include Obelia geniculata, O. dichotoma, O. longissima, Sertularia cupressina, Tublaria indivisa and Thuiaria thuja. The difficulty in identifying hydroids suggests many more species may be also be present. Other species typically found in this biotope include ephemeral green algae (Enteromorpha spp. and Ulva sp.), red algae (Chondrus crispus and Coralline algae) and the winkle Littorina littorea. Within the pools, patches of sand may be occupied by the lugworm Arenicola marina and sand mason worms Lanice conchilega. These pools are often associated with mussel beds (MytX), with Mytilus edulis frequently recorded within the pools. Barnacles (Semibalanus balanoides and Elminius modestus) and the keel worm Pomatoceros triqueter may be attached to shells and small stones. Mobile species typical of rock pool habitats, such as Crangon crangon and Pomatoschistus minutus will also be found within the pool.

Situation

No situation data available.

Temporal variation

No temporal data available.

Characterising Species

Taxon Typical abundance - SACFOR scale % of core records where taxon was recorded
Hydrozoa Abundant 81-100 %
Obelia longissima Common 21-40 %
Arenicola marina 21-40 %
Lanice conchilega Occasional 41-60 %
Pomatoceros triqueter Rare 21-40 %
Elminius modestus Frequent 41-60 %
Semibalanus balanoides Frequent 41-60 %
Crangon crangon 21-40 %
Carcinus maenas Rare 41-60 %
Littorina littorea Common 41-60 %
Mytilus edulis Abundant 61-80 %
Corallinaceae Frequent 41-60 %
Chondrus crispus Occasional 41-60 %
Fucus vesiculosus Rare 21-40 %
Enteromorpha Rare 61-80 %

Similar biotopes

Not applicable or unknown.

Biotope history

Classification Habitat code
6.95 LMXD.HYD
96.7 RKP.H

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