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SS.SMx.CMx.FluHyd
Flustra foliacea and Hydrallmania falcata on tide-swept circalittoral mixed sediment

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Habitat (physical) description

Distribution

 Salinity: Full (30-35 ppt) 
 Wave exposure: Exposed, Moderately exposed 
 Tidal streams: Strong (3-6 kn), Moderately strong (1-3 kn) 
 Substratum: Boulders, cobbles or pebbles with gravel and sand 
 Zone: Circalittoral 
 Depth Band: 5-10 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.

Previous code

This biotope occurred in previous versions of the classification as:
MCR.Flu.SerHyd - Version: 97.06

Distribution of habitat SS.SMx.CMx.FluHyd  Flustra foliacea and Hydrallmania falcata on tide-swept circalittoral mixed sediment
Distribution of habitat SS.SMx.CMx.FluHyd Flustra foliacea and Hydrallmania falcata on tide-swept circalittoral mixed sediment, based on records on the UK Marine Recorder database and EUSeaMap. Red dots represent records on which the biotope is based. Blue dots show other certain records, black dots show records tentatively assigned to this biotope. Yellow areas show level 2 and 3 sublittoral and deep-sea habitats prediced by EUSeaMap within UK waters.

Biotope description

This biotope represents part of a transition between sand-scoured circalittoral rock where the epifauna is conspicuous enough to be considered as a biotope and a sediment biotope where an infaunal sample is required to characterise it and is possibly best considered an epibiotic overlay. Flustra foliacea and the hydroid Hydrallmania falcata characterise this biotope; lesser amounts of other hydroids such as Sertularia argentea, Nemertesia antennina and occasionally Nemertesia ramose, occur where suitably stable hard substrata is found. The anemone Urticina feline and the soft coral Alcyonium digitatum may also characterise this biotope. Barnacles Balanus crenatus and tube worms Pomatoceros triqueter may be present and the robust bryozoans Alcyonidium diaphanum and Vesicularia spinosa appear amongst the hydroids at a few sites. Sabella pavonina and Lanice conchilega may be occasionally found in the coarse sediment around the stones. In shallower (i.e. upper circalittoral) examples of this biotope scour-tolerant robust red algae such as Polysiphonia nigrescens, Calliblepharis spp. and Gracilaria gracilis are found.

Situation

This biotope is found around most coasts, although regional differences are seen where one or two similarly scour-tolerant species such as Styela clava and Crepidula fornicata (Solent) occupy the hard substrata

Temporal variation

No temporal data available.

Similar biotopes

SS.SSa.IFiSa.ScupHydWith increased scouring and more sand S. cupressina becomes more common and FluHyd may develop into ScupHyd.
SS.SCS.CCS.PomBOn pebble plains, as tidal stream strength increases to a point at which the stones are regularly mobilised, all hydroids are scoured off leaving just Pomatoceros, bryozoan crusts, Balanus crenatus and coralline algae.
SS.SMx.IMx.CreAsAnCreAsAn is found in shallower water in slightly less exposed areas with a lower proportion of cobbles and pebbles and in slightly weaker currents.

Characterising Species

Taxa Frequency Typical Abundance % Contribution to similarity Abundance (no.2)
Halecium halecinum O 1
Hydrallmania falcata O 11
Sertularia argentea O 3
Nemertesia antennina O 7
Nemertesia ramosa O 1
Alcyonium digitatum O 5
Urticina felina O 8
Pomatoceros triqueter O 3
Balanus crenatus F 1
Pagurus bernhardus O 6
Alcyonidium diaphanum O 5
Vesicularia spinosa F 2
Flustra foliacea F 18
Crossaster papposus O 2
Asterias rubens O 10

Example photographs of biotope

No characteristic photos currently available. If you are able to provide a photograph of this biotope please contact .


Version 15.03 of the classification adds a deep-sea section to version 04.05; therefore superseding version 04.05, 97.06 and 03.02.

This online classification should be cited as:

JNCC (2015) The Marine Habitat Classification for Britain and Ireland Version 15.03 [Online]. [Date accessed]. Available from: jncc.defra.gov.uk/MarineHabitatClassification

Information from the shallower section (up to sublittoral sediment, taken from Version 04.05) be cited as the report accompanying Version 04.05, as follows:

CONNOR, D.W., J.H. ALLEN, N.GOLDING, K.L.HOWELL, L.M. LIEBERKNECHT, K.O. NORTHEN AND J.B. REKER (2004) The Marine Habitat Classification for Britain and Ireland Version 04.05. In: JNCC (2015) The Marine Habitat Classification for Britain and Ireland Version 15.03 [Online]. [Date accessed].
Available from: jncc.defra.gov.uk/MarineHabitatClassification
ISBN 1 861 07561 8


Information from the deep-sea section (added in March 2015) should be cited as the report accompanying the deep-sea section, as follows:

PARRY, M.E.V., K.L. HOWELL, B.E. NARAYANASWAMY, B.J. BETT, D.O.B. JONES, D.J. HUGHES, N. PIECHAUD, T.D. NICKELL, H. ELLWOOD, N. ASKEW, C. JENKINS and E. MANCA (2015) A Deep-sea Section for the Marine Habitat Classification of Britain and Ireland. JNCC report 530. In: JNCC (2015) The Marine Habitat Classification for Britain and Ireland Version 15.03 [Online]. [Date accessed].
Available from: jncc.defra.gov.uk/MarineHabitatClassification
ISSN 0963 8901