Flustra foliacea on slightly scoured silty circalittoral rock

English name: Flustra foliacea on slightly scoured silty circalittoral rock

Quick facts

EUNIS habitat type code A4.2141
Bern Convention Included in a Resolution 4 habitat type at a higher level (A4)

Description (English)

This variant is typically found on the upper faces of moderately wave-exposed circalittoral bedrock or boulders subjected to moderately strong tidal streams. These rocky patches may be interspersed with gravelly sand patches, causing a scouring effect. From afar, the variant appears dominated by the bryozoan Flustra foliacea. Alcyonium digitatum may also be seen attached to the rocky substratum. Under closer inspection, the white tubes of the polychaete Pomatoceros triqueter may be observed on the rock and boulders, especially on vertical faces. There may be sandy/gravelly patches in between the boulders colonised by the anemone Urticina felina. The regular occurrence of large numbers of the sea urchin Echinus esculentus in this biotope may be responsible for grazing the faunal and algal turf, thus keeping species richness relatively low. Other echinoderms that may be seen include the ubiquitous starfish Asterias rubens and the common brittlestar Ophiothrix fragilis. Sparse clumps of the hydroids Thuiaria thuja, Abietinaria abietina, Nemertesia antennina and Tubularia indivisa are occasionally seen attached to the rocky substratum. The hermit crab Pagurus bernhardus, the polychaete Sabella pavonina and sparse bryozoan crusts may also be present. This biotope is characteristic of the bedrock terraces along the Northumberland coast that are generally species impoverished compared to similar F. foliacea biotopes on the west coasts of the UK, which have a more diverse range of sponges, hydroids and bryozoans. As the turbidity levels increase in this fairly silty biotope, so the species diversity is reduced.
Situation: This biotope typically occurs around coasts subject to sand scour and siltation. Associated biotopes common around the north-east coast of England include circalittoral gravel and coarse sands. Typical species present include Echinocardium, Lanice conchilega, Ensis spp., Mya truncata and Myxicola. Where suitable substratum is available, exposed kelp forests occur in the infralittoral (the latter normally occupies a narrow band due to the high silt loading in the water column). Where this biotope occurs along with chalk or limestone bedrock and boulders, piddock dominated biotopes (Pid) may also be found.

Source: EUNIS habitat classification

Vegetation types

Relation to vegetation types (syntaxa)

Not available

Species mentioned in habitat description

Invertebrates Abietinaria abietina
Invertebrates Alcyonium digitatum
Invertebrates Asterias rubens
Invertebrates Echinus esculentus
Invertebrates Flustra foliacea
Invertebrates Lanice conchilega
Invertebrates Mya truncata
Invertebrates Nemertesia antennina
Invertebrates Ophiothrix fragilis
Invertebrates Pagurus bernhardus
Invertebrates Pomatoceros triqueter
Invertebrates Sabella pavonina
Invertebrates Thuiaria thuja
Invertebrates Tubularia indivisa
Invertebrates Urticina felina
Species scientific name English common name Species group
Abietinaria abietina Invertebrates
Alcyonium digitatum Invertebrates
Asterias rubens Invertebrates
Echinus esculentus Invertebrates
Flustra foliacea Invertebrates
Lanice conchilega Invertebrates
Mya truncata Invertebrates
Nemertesia antennina Invertebrates
Ophiothrix fragilis Invertebrates
Pagurus bernhardus Invertebrates
Pomatoceros triqueter Invertebrates
Sabella pavonina Invertebrates
Thuiaria thuja Invertebrates
Tubularia indivisa Invertebrates
Urticina felina Invertebrates

Other classifications

Classification Code Habitat type name Relationship type
Marine Habitat Classification Britain/Ireland 0405 CR.MCR.EcCr.FaAlCr.Flu <I>Flustra foliacea</I> on slightly scoured silty circalittoral rock 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 A4.2141 Flustra foliacea on slightly scoured silty circalittoral rock same
EUNIS Habitat Classification 200308 A3.6221 Flustra foliacea on slightly scoured silty circalittoral rock same
EUNIS Habitat Classification 200202 A3.6221 Flustra foliacea on slightly scoured silty circalittoral rock or mixed substrata same
EUNIS Habitat Classification 199910 A3.6221 Flustra foliacea on slightly scoured silty circalittoral rock or mixed substrata same
MNCR BioMar 97.06 (Britain & Ireland) MCR.ByH.Flu.Flu Flustra foliacea on slightly scoured silty circalittoral rock or mixed substrata same
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