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SS.SMu.ISaMu.NhomMac
Nephtys hombergii and Macoma balthica in infralittoral sandy mud

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Habitat (physical) description

Distribution

 Salinity: Full (30-35 ppt), Variable (18-35 ppt) 
 Wave exposure: Moderately exposed, Sheltered, Extremely sheltered 
 Tidal streams: Weak (>1 kn) 
 Substratum: Sandy mud 
 Zone: Infralittoral 
 Depth Band: 5-10 m, 10-20 m 
 Other Features: Organically enriched 

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:
IMS.FaMS.MacAbr - Version: 97.06
IMS.AbrLag - Version: 96.7

Distribution of habitat SS.SMu.ISaMu.NhomMac  Nephtys hombergii and Macoma balthica in infralittoral sandy mud
Distribution of habitat SS.SMu.ISaMu.NhomMac Nephtys hombergii and Macoma balthica in infralittoral sandy mud, 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

Near-shore shallow sandy muds and muds, and sometimes mixed sediments, may be characterised by the presence of the polychaete Nephtys hombergii and the bivalve Macoma balthica. Abra alba, and Nucula nitidosa may also be important although they may not necessarily occur simultaneously or in high numbers. Other taxa include Spiophanes bombyx, Lagis koreni, and Echinocardium cordatum. In some areas Scoloplos armiger and Crangon crangon may also be present. The community appears to be quite stable (Dewarumez et al. 1992) and the substratum is typically rich in organic content. This community has been included in the 'Boreal Offshore Muddy Sand Association' of Jones (1950) and is also described by several other authors (Petersen 1918; Cabioch & Gla‡on 1975). A similar community may occur in deep water in the Baltic (Thorson 1957). This biotope may occur in slightly reduced salinity estuarine conditions where Mya sp. may become a significant member of the community (Thorson 1957).

Situation

The community may occur in small patches or swathes in shallow waters parallel to the shore (Jones 1950; Cabioch & Gla‡on 1975) or in shallow nearshore depressions or trenches where finer material collects e.g. off the Suffolk coast (IECS 1991). This biotope is known to occur in patches between Denmark and the western English Channel.

Temporal variation

Sites with SMU.NhomMac may develop into Amphiura biotopes with time (E.I.S. Rees pers. comm. 1996)

Similar biotopes

SS.SSa.CMuSa.AalbNucIn deeper, less muddy areas NhomMac may grade into AalbNuc and it is possible that this biotope is part of the Abra dominated muddy sand biotopes.

Characterising Species

Taxa Frequency Typical Abundance % Contribution to similarity Abundance (no.2)
Nephtys cirrosa
Nephtys hombergii C 37 57
Spiophanes bombyx P 3 11
Magelona mirabilis P 1 4
Lagis koreni P 3 9
Nucula nitidosa F 18 109
Macoma balthica F 20 41
Abra alba P 6 13
Ophiura ophiura P 2 9
Echinocardium cordatum P 3 16

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