Skip to Content

Marine Habitat Classification


Description of biotope or habitat type

To understand more about what this page is describing, see How to use the classification. See also How to cite.

   Urticina felina and sand-tolerant fauna on sand-scoured or covered circalittoral rock


Habitat (physical) description

Salinity Full (30-35 ppt), Reduced (18-30ppt)
Wave exposure Extremely exposed, Very exposed, Exposed, Moderately exposed, Sheltered, Very sheltered, Extremely sheltered
Tidal streams Strong (3-6 kn), Moderately strong (1-3 kn)
Substratum Bedrock, cobbles
Zone Circalittoral
Depth Band 0-5 m, 10-20 m, 20-30 m, 30-50 m
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 CR.MCR.EcCr.UrtScr <I>Urticina felina</I> and sand-tolerant fauna on sand-scoured or covered circalittoral 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'
  • Predicted extent of the level 3 (for sublittoral rock & deep sea) or 4 (for sublittoral sediment) habitat

Point data based on records in the UK Marine Recorder Snapshot. Predicted habitat extent is from UKSeaMap.

Description

This biotope typically occurs on tide-swept circalittoral bedrock, rock adjacent to mobile sand/gravel in gullies, and cobbles on gravel and sand, characterised by scour-tolerant robust species. Although many of these species are found on subtidal rock, they tend to occur in larger numbers in these highly sand-influenced conditions. The dominant species by far is the anemone Urticina felina which commonly occurs on rocks at the sand-rock interface, where the scour levels are at a maximum and few species can tolerate this abrasion. The sponge Ciocalypta penicillus is also very characteristic of shifting sand-covered rock. This biotope is only occasionally recorded as a separate entity, because its extent is typically restricted to a very narrow band of rock at the sediment interface. Only occasionally does it cover a large extent of rock (e.g. where the wave action is strong enough to cause sand abrasion well up the rock face or where the rock is low-lying). More often, this scoured zone is recorded as part of whatever biotope occurs on the nearby hard substrata. Other species (which are able to survive, and benefit from the reduced competition) include Balanus crenatus, Pomatoceros triqueter, Cellepora pumicosa, Alcyonidium diaphanum, Cliona celata, encrusting red algae and Asterias rubens.

Situation

This biotope tends to be found in close proximity to mobile sand or gravel, producing scour that tends to limit the number of species found.

Temporal variation

Not known.

Characterising Species

Taxon Relative importance of taxon for defining this community (%) Typical abundance - SACFOR scale % of core records where taxon was recorded
Cliona celata 1 Rare 21-40 %
Ciocalypta penicillus 1 Common 1-20 %
Urticina felina 51 Common 81-100 %
Pomatoceros triqueter 4 Common 21-40 %
Balanus crenatus 29 Abundant 61-80 %
Alcyonidium diaphanum 1 21-40 %
Cellepora pumicosa 4 41-60 %
Asterias rubens 4 Rare 41-60 %
Corallinaceae 1 Frequent 21-40 %

Similar biotopes

Not applicable or unknown.

Photos

CR.MCR.ECCR.UrtScr Urticina felina and sand-tolerant fauna on sand-scoured or covered circalittoral rock, Carreg-trai, Ramsey. Rohan Holt © JNCC
CR.MCR.ECCR.UrtScr Urticina felina and sand-tolerant fauna on sand-scoured or covered circalittoral rock, Carreg-trai, Ramsey. Rohan Holt © JNCC
CR.MCR.ECCR.UrtScr Urticina felina and sand-tolerant fauna on sand-scoured or covered circalittoral rock, Outer Aberdaran Bay. Keith Hiscock © JNCC
CR.MCR.ECCR.UrtScr Urticina felina and sand-tolerant fauna on sand-scoured or covered circalittoral rock, Outer Aberdaran Bay. Keith Hiscock © JNCC

Back to top