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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.

   Echinocardium cordatum and Ensis spp. in lower shore and shallow sublittoral slightly muddy fine sand

Physical habitat description

Salinity Full (30-35 ppt)
Wave exposure Exposed, Moderately exposed, Sheltered
Tidal streams Moderately strong (1-3 kn), Weak (>1 kn), Very weak (negligible)
Substratum Medium to fine sand; slightly muddy sand
Zone Infralittoral
Depth Band 5-10 m, 10-20 m, 20-30 m, Lower shore
Other Features

Biotope origin

Derived using data from Various
Faunal group Epifauna

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 SS.SSa.IMuSa.EcorEns <I>Echinocardium cordatum</I> and <I>Ensis</I> spp. in lower shore and shallow sublittoral slightly muddy fine sand

  • 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.


Sheltered lower shore and shallow sublittoral sediments of sand or muddy fine sand in fully marine conditions, support populations of the urchin Echinocardium cordatum and the razor shell Ensis siliqua or Ensis ensis. Other notable taxa within this biotope include occasional Lanice conchilega, Pagurus, Liocarcinus spp. and Asterias rubens. This biotope has primarily been recorded by epifaunal dive, video or trawl surveys where the presence of relatively conspicuous taxa such as E. cordatum and Ensis spp. have been recorded as characteristic of the community. However, these species, particularly E. cordatum, have a wide distribution and are not necessarily the best choice for a characteristic taxa (Thorson, 1957). Furthermore, detailed quantitative infaunal data for this biotope is rather scarce, possibly as a result of survey method as remote grab sampling is likely to under-estimate deep-burrowing species such as Ensis sp. (Warwick & Davis 1977). Consequently, it may be better to treat this biotope as an epibiotic overlay which is likely to overlap with a number of other biotopes such as SS.SSa.IMuSa.FfabMag, SS.SSa.IFiSa.NcirBat and SS.SSa.CMuSa.AalbNuc with infaunal components of these biotopes occurring within SS.SSa.IMuSa.EcorEns. The precise nature of this infaunal community will be related to the nature of the substratum, in particular the quantity of silt/clay present. Infaunal species may include the polychaetes Spiophanes bombyx, Magelona mirabilis, Nephtys cirrosa and Chaetozone setosa and the amphipod Bathyporeia spp. This biotope is currently broadly defined and needs further consideration as to whether it should be placed at biotope or biotope complex level. SS.SSa.IMuSa.AreISa is another biotope based primarily on epibiotic data. It is likely that this biotope and SS.SSa.IMuSa.EcorEns form a wider epibiotic sand /muddy sand community with SS.SSa.IMuSa.EcorEns biased towards sandier areas and SS.SSa.IMuSa.AreISa towards slightly muddier areas.


No situation data available.

Temporal variation

No temporal data available.

Characterising species

Taxon Relative importance of taxon for defining this community (%) Typical abundance - SACFOR scale % of core records where taxon was recorded
Spiophanes bombyx 37 Common 61-80%
Echinocardium cordatum 34 Frequent 81-100%
Lanice conchilega 14 Occasional 61-80%
Ensis 10 Frequent 41-60%
Magelona mirabilis 10 Common 41-60%
Pagurus bernhardus 9 Occasional 61-80%
Nephtys cirrosa 8 Common 41-60%
Asterias rubens 7 Occasional 41-60%
Chaetozone setosa 6 41-60%
Bathyporeia pelagica 5 Common 21-40%
Bathyporeia elegans 3 Common 21-40%
Iphinoe trispinosa 3 Frequent 41-60%
Pleuronectidae 2 Frequent 21-40%
Arenicola marina 2 Occasional 21-40%
Chamelea gallina 2 21-40%
Corystes cassivelaunus 2 Rare 21-40%
Ensis ensis 2 Super abundant 1-20%
Ensis siliqua 2 Frequent 21-40%
Glycera tridactyla 2 21-40%
Tritia reticulata 2 Frequent 21-40%
Liocarcinus depurator 2 Occasional 21-40%
Magelona filiformis 2 21-40%
Pomatoschistus 2 Occasional 21-40%
Macomangulus tenuis 1 21-40%
Astropecten irregularis 1 Occasional 21-40%
Echinocardium cordatum 1 41-60%
Eteone longa 1 Abundant 21-40%
Euspira nitida 1 Rare 21-40%
Centraloecetes kroyeranus 1 21-40%
Tellimya ferruginosa 1 21-40%

Similar biotopes or habitat types

In some areas the seagrass Zostera subg. Zostera marina may occur in low densites in this biotope but does not form distinct beds as in SS.SMp.SSgr.Zmar.

Classification history of this biotope or habitat type

Classification version Code Habitat name
2015 (15.03) SS.SSa.IMuSa.EcorEns Echinocardium cordatum and Ensis spp. in lower shore and shallow sublittoral slightly muddy fine sand
2004 (04.05) SS.SSa.IMuSa.EcorEns Echinocardium cordatum and Ensis spp. in lower shore and shallow sublittoral slightly muddy fine sand
1997 (97.06) SS.IMS.FaMS.EcorEns Echinocardium cordatum and Ensis spp. in lower shore or shallow sublittoral muddy fine sand
1996 (6.95) IGS.EcorEsil

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