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Marine Habitat Classification

Description of biotope or habitat type

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   Moerella spp. with venerid bivalves in infralittoral gravelly 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)
Substratum Medium to coarse sand and gravelly sand
Zone Infralittoral
Depth Band 0-5 m, 5-10 m, 10-20 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.

Distribution of habitat SS.SCS.ICS.MoeVen <I>Moerella</I> spp. with venerid bivalves in infralittoral gravelly 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.


Infralittoral medium to coarse sand and gravelly sand which is subject to moderately strong water movement from tidal streams may be characterised by Moerella spp. with the polychaete Glycera lapidum (agg.) and venerid bivalves. Typical species include Moerella pygmaea or M. donacina with other robust bivalves such as Dosinia lupinus, Timoclea ovata, Goodallia triangularis and Chamelea gallina. Other infauna include nephtyd and spionid polychaetes and amphipod crustacea. Another important component of this biotope in some areas is the bivalve Spisula solida (see Khne & Rachnor 1996) which may be common or abundant. In conjunction with FfabMag this biotope may form part of the 'Shallow Venus Community', the 'Boreal Off-shore Sand Association' and the 'Goniadella-Spisula association' of previous workers (see Petersen 1918; Jones 1951; Thorson 1957; Salzwedel, Rachor & Gerdes 1985). Epifaunal communities may be reduced in this biotope when compared to FfabMag; both types may have surface sand waves which may be indicative of the presence of venerid bivalves (Warwick & Davies 1977). This hypothesis, however, requires testing. Remote grab sampling is likely to under-estimate venerid bivalves and other deep-burrowing and more dispersed species such as Paphia, Ensis and Spatangus. In southern areas of the UK and the North Sea, in slightly siltier sand and shelly sand, SCS.MoeVen may give way to the other Spisula biotope SSA.SsubNhom. Together these two biotopes replace the old biotope IGS.Sell.


This biotope is found on the exposed open coast and in estuaries with moderately strong tidal currents.

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
Anemonia viridis 1 Occasional 21-40 %
Nemertea 5 Common 61-80 %
Nematoda 5 Frequent 41-60 %
Pisione remota 9 Common 21-40 %
Glycera lapidum 7 Common 61-80 %
Streptosyllis websteri 1 21-40 %
Nephtys cirrosa 3 41-60 %
Aonides paucibranchiata 1 Frequent 21-40 %
Spio filicornis 4 41-60 %
Spiophanes bombyx 1 21-40 %
Lanice conchilega 10 Occasional 41-60 %
Bathyporeia pelagica 1 Frequent 21-40 %
Apseudes latreillii 6 Common 21-40 %
Pagurus bernhardus 16 Occasional 41-60 %
Liocarcinus depurator 6 Occasional 21-40 %
Carcinus maenas 2 Occasional 21-40 %
Goodallia triangularis 1 Frequent 21-40 %
Spisula solida 1 Common 21-40 %
Moerella donacina 11 Abundant 41-60 %
Moerella pygmaea 8 Frequent 41-60 %
Chamelea gallina 1 21-40 %
Timoclea ovata 2 Common 21-40 %
Dosinia lupinus 2 21-40 %
Echinocyamus pusillus 5 41-60 %
Callionymus lyra 1 Occasional 21-40 %
Pomatoschistus minutus 32 Frequent 61-80 %
Chondrus crispus 1 Occasional 21-40 %
Polyides rotundus 1 Occasional 21-40 %
Gracilaria gracilis 9 Frequent 41-60 %
Laminaria saccharina 1 Occasional 21-40 %
Ulva 4 Frequent 21-40 %

Similar biotopes or habitat types

Similar biotope found in deeper water than MoeVen (generally greater than 15-20m), with increased importance of Mediomastus fragilis and Lumbrineris spp.

More stable than MoeVen, where reduced exposure and/or tidal currents result in a muddy sandy bottom. The community is dominated by Fabulina fabula and Magelona mirabilis.

In areas where the sediment is subject to continual disturbance by wave action MoeVen grades into Glap, which is more impoverished and lacks the venerid bivalve communities.

On exposed lower shore sand MoeVen may give way to Po.Ang

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