Alcyonium digitatum and faunal crust communities on vertical circalittoral bedrock

English name: Alcyonium digitatum and faunal crust communities on vertical circalittoral bedrock

Quick facts

EUNIS habitat type code A4.215
Bern Convention Included in a Resolution 4 habitat type at a higher level (A4)

Description (English)

This biotope typically occurs on the vertical faces and overhangs of exposed to moderately exposed lower infralittoral and upper circalittoral bedrock subject to moderately strong to weak tidal streams. Due to the large numbers of the urchin Echinus esculentus often recorded, this biotope tends to have a grazed appearance, and the bedrock is often encrusted with pink coralline algae, encrusting bryozoans such as Parasmittina trispinosa and the calcareous tubeworm Pomatoceros triqueter. Dense aggregations of dead mans fingers Alcyonium digitatum may be present along with the cup coral Caryophyllia smithii. Other species present include the echinoderms Asterias rubens, Ophiothrix fragilis and Antedon bifida, the ascidians Clavelina lepadiformis, Ciona intestinalis and Ascidia mentula, the anthozoans Urticina feline, Cortynactis viridis, Metridium senile and Sagartia elegans, the gastropod Calliostoma zizyphinum and the crustacean Cancer pagurus. Three regional variations of this biotope have been recorded. One variant found typically off the north-east coast of Scotland and around the Northern Isles, has a very impoverished appearance dominated by anthozoans. A second variant occurs along the west coast of Scotland, extending to Rockall in the west, and the Northern Isles in the north-east, and has a more fauna, characterised by hydroids, sponges, anthozoans and echinoderms. A third variant occurs along the north-east coast of England (Northumberland) up to the Northern Isles and is dominated by Alcyonium digitatum, brittlestars and Echinus esculentus.

Source: EUNIS habitat classification

Vegetation types

Relation to vegetation types (syntaxa)

Not available

Species mentioned in habitat description

Invertebrates Alcyonium digitatum
Invertebrates Antedon bifida
Invertebrates Ascidia mentula
Invertebrates Asterias rubens
Invertebrates Calliostoma zizyphinum
Invertebrates Cancer pagurus
Invertebrates Caryophyllia smithii
Invertebrates Ciona intestinalis
Invertebrates Clavelina lepadiformis
Invertebrates Echinus esculentus
Invertebrates Metridium senile
Invertebrates Ophiothrix fragilis
Invertebrates Parasmittina trispinosa
Invertebrates Pomatoceros triqueter
Invertebrates Sagartia elegans
Species scientific name English common name Species group
Alcyonium digitatum Invertebrates
Antedon bifida Invertebrates
Ascidia mentula Invertebrates
Asterias rubens Invertebrates
Calliostoma zizyphinum Invertebrates
Cancer pagurus Invertebrates
Caryophyllia smithii Invertebrates
Ciona intestinalis Invertebrates
Clavelina lepadiformis Invertebrates
Echinus esculentus Invertebrates
Metridium senile Invertebrates
Ophiothrix fragilis Invertebrates
Parasmittina trispinosa Invertebrates
Pomatoceros triqueter Invertebrates
Sagartia elegans Invertebrates

Other classifications

Classification Code Habitat type name Relationship type
Marine Habitat Classification Britain/Ireland 0405 CR.MCR.EcCr.AdigVt <I>Alcyonium digitatum</I> and faunal crust communities on vertical circalittoral bedrock source
CORINE Land Cover 5.2.3. Sea and ocean n/a
For relation to plant communities (syntaxa), see Vegetation types

History

Classification Code Habitat type name Relationship type
EUNIS Habitat Classification 200410 A4.215 Alcyonium digitatum and faunal crust communities on vertical circalittoral bedrock same
EUNIS Habitat Classification 200308 A3.69 Faunal turfs on vertical circalittoral rock wider
EUNIS Habitat Classification 200308 A3.692 Bugula spp. and other bryozoans on vertical moderately exposed circalittoral rock overlap
EUNIS Habitat Classification 200308 A3.241 Alcyonium digitatum and a bryozoan, hydroid and ascidian turf on vertical moderately exposed infralittoral rock narrower
EUNIS Habitat Classification 200202 A3.241 Alcyonium digitatum and a bryozoan, hydroid and ascidian turf on vertical moderately exposed infralittoral rock overlap
EUNIS Habitat Classification 200202 A3.69 Faunal turfs on vertical circalittoral rock overlap
EUNIS Habitat Classification 200202 A3.692 Bugula spp. and other bryozoans on vertical moderately exposed circalittoral rock overlap
EUNIS Habitat Classification 199910 A3.241 Alcyonium digitatum and a bryozoan, hydroid and ascidian turf on vertical moderately exposed infralittoral rock overlap
EUNIS Habitat Classification 199910 A3.69 Faunal turfs on vertical circalittoral rock overlap
EUNIS Habitat Classification 199910 A3.692 Bugula spp. and other bryozoans on vertical moderately exposed circalittoral rock overlap
EUNIS Habitat Classification 199811 A3.68 Faunal turfs on deep vertical circalittoral rock overlap
MNCR BioMar 97.06 (Britain & Ireland) CR.FaV Faunal turfs (deep vertical rock) overlap
MNCR BioMar 97.06 (Britain & Ireland) CR.FaV.Bug Bugula spp. and other bryozoans on vertical moderately exposed circalittoral rock overlap
MNCR BioMar 97.06 (Britain & Ireland) IR.FaSwV.AlcByH Alcyonium digitatum and a bryozoan, hydroid and ascidian turf on vertical moderately exposed vertical infralittoral rock overlap
European Environment Agency (EEA)
Kongens Nytorv 6
1050 Copenhagen K
Denmark
Phone: +45 3336 7100