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Marine Habitat Classification

Description of biotope or habitat type

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   Sabellaria alveolata on variable salinity sublittoral mixed sediment

Physical habitat description

Salinity Variable (18-35 ppt)
Wave exposure Exposed, Moderately exposed, Sheltered
Tidal streams Strong (3-6 kn), Weak (>1 kn)
Substratum Mixed sandy sediment with pebble and cobbles
Zone Infralittoral
Depth Band 0-5 m, 5-10 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.SBR.PoR.SalvMx <I>Sabellaria alveolata</I> on variable salinity sublittoral mixed sediment

  • 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.


Tide-swept sandy mixed sediments with cobbles and pebbles, in variable salinity or fully marine conditions, may be characterised by surface accumulations of the reef building polychaete Sabellaria alveolata. The presence of Sabellaria sp. has a strong influence on the associated infauna as the tubes bind the surface sediments together and provide increased stability. Such reefs may form large structures up to a metre in height although they are considerably less extensive than the intertidal reefs formed by this species (Salv). Other associated species may include the polychaete Melinna cristata, itself often as dense aggregations, mobile surface feeding polychaetes including Typosyllis armillary and Eulalia tripunctata. Other polychaetes may include Mediomastus fragilis and Pygospio elegans whilst amphipods such as Harpinia pectinata and tubificid oligochaetes may also be found.


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 Typical abundance - (count per m2) % of core records where taxon was recorded
Golfingia vulgaris vulgaris 2 56 41-60 %
Eulalia tripunctata 7 Abundant 74 61-80 %
Typosyllis armillaris 66 Frequent 4 41-60 %
Pygospio elegans 1 Frequent 15 21-40 %
Mediomastus fragilis 4 Common 168 41-60 %
Sabellaria alveolata 66 Super abundant 1646 81-100 %
Melinna cristata 2 Abundant 79 41-60 %
Harpinia pectinata 2 Frequent 34 21-40 %

Similar biotopes or habitat types

SalvMx has a reduced species richness in comparison with SspiMx, particularly in mature S. alveolata beds where the species tends to completely cover the seabed allowing few other species to colonise the habitat.

The reefs formed in sublittoral sediments are considerably less extensive than the intertidal reefs formed by this species.

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