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Marine Habitat Classification


Description of biotope or habitat type

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   Prasiola stipitata on nitrate-enriched supralittoral or littoral fringe rock


Habitat (physical) description

Salinity Full (30-35 ppt)
Wave exposure Exposed, Moderately exposed
Tidal streams
Substratum Bedrock; boulders
Zone Littoral fringe, Supralittoral
Depth Band Upper shore
Other Features Nitrate enrichment

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.Lic.Pra <I>Prasiola stipitata</I> on nitrate-enriched supralittoral or 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.

Description

Exposed to moderately exposed bedrock and large boulders in the supralittoral and littoral fringe that receives nitrate enrichment from nearby roosting sea birds and is characterised by a band or patches of the ephemeral tufty green seaweed Prasiola stipitata or Prasiola spp. This typically grows over the black lichen Verrucaria maura in the littoral fringe or yellow and grey lichens in the supralittoral zone. In damp pits and crevices, species such as the winkle Littorina saxatilis, amphipods and halacarid mites are occasionally found. Pra often covers a smaller area than 5m x 5m and care should be taken to notice/record this biotope. The biotope can be associated with artificial substrata such as septic tanks, and in supralittoral areas influenced by sewage seeps or agricultural run-off.

Situation

This biotope is found at the top of rocky shores in the splash zone below colonies of nesting or roosting birds growing. Pra may also be found at the entrances to and on the ceilings of littoral caves or in patches on large boulders, where birds may be roosting. It can be found in the YG or Ver.Ver zones.

Temporal variation

P. stipitata reaches its maximum abundance during the winter months. It generally dies out during the summer in southern Britain, when the biotope reverts to either YG or Ver.Ver. In the cooler northern areas it may be present all year round.

Characterising Species

Taxon Relative importance of taxon for defining this community (%) Typical abundance - SACFOR scale % of core records where taxon was recorded
Littorina saxatilis 9 Frequent 41-60 %
Prasiola stipitata 52 Common 81-100 %
Verrucaria maura 35 Abundant 61-80 %

Similar biotopes

LR.FLR.Lic.YG
Occurs in similar physical conditions in the supralittoral zone, but is not subject to a nitrate enriched environment. Pra has a higher density of P. stipitata, which overgrows any yellow and grey lichens that may survive in the littoral fringe.

LR.FLR.Lic.Ver.Ver
Occurs in similar physical conditions in the littoral fringe, but is not subject to a nitrate enriched environment. Pra has a higher density of P. stipitata, which overgrows V. maura.

Biotope history

Classification Habitat code
6.95 LRK.PRA

Photos

LR.FLR.LIC.Pra Prasiola stipitata on nitrate-enriched supralittoral or littoral fringe rock, Low Newton, Seahouses. Judy Foster-Smith © JNCC
LR.FLR.LIC.Pra Prasiola stipitata on nitrate-enriched supralittoral or littoral fringe rock, Low Newton, Seahouses. Judy Foster-Smith © JNCC
LR.FLR.LIC.Pra Prasiola stipitata on nitrate-enriched supralittoral or littoral fringe rock, Unspecified location. M D Guiry © M D Guiry
LR.FLR.LIC.Pra Prasiola stipitata on nitrate-enriched supralittoral or littoral fringe rock, Unspecified location. M D Guiry © M D Guiry

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