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Marine Habitat Classification

Description of biotope or habitat type

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   Sublittoral mixed sediment in low or reduced salinity (lagoons)

Physical habitat description

Salinity Low (<18ppt)
Wave exposure
Tidal streams Weak (>1 kn)
Substratum Muddy mixed sediment
Zone Infralittoral, Sublittoral fringe
Depth Band 0-5 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.SMx.SMxLS Sublittoral mixed sediment in low or reduced salinity (lagoons)

  • 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.


Shallow, muddy mixed sediments in areas of low or reduced, although stable, salinity (may vary annually) with largely ephemeral faunal communities. Characterised infaunally by oligochaetes, including Heterochaeta costata and members of the Enchytraeidae, polychaetes such as Hediste diversicolor, Polydora ciliata and Pygospio elegans,and bivalves such as Mya arenaria and the lagoon cockle Cerastoderma glaucum. These bivalve species may also form conspicuious members of the epifauna together with more ubiquitous species like the common goby Pomatoschistus microps.


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
Hediste diversicolor 25 Super abundant 61-80 %
Hediste diversicolor 31 Frequent 81-100 %
Polydora ciliata 3 Abundant 41-60 %
Pygospio elegans 5 Common 41-60 %
Alkmaria romijni 2 Rare 21-40 %
Heterochaeta costata 20 Abundant 61-80 %
Heterochaeta costata 17 Frequent 61-80 %
Enchytraeidae 34 Abundant 61-80 %
Neomysis integer 2 Rare 21-40 %
Corophium volutator 1 41-60 %
Sphaeroma hookeri 2 Occasional 21-40 %
Palaemonetes varians 3 Occasional 21-40 %
Chironomida 16 Occasional 61-80 %
Hydrobia ulvae 4 Common 41-60 %
Hydrobia ulvae 1 Rare 21-40 %
Cerastoderma glaucum 3 Common 41-60 %
Cerastoderma glaucum 6 Common 21-40 %
Mya arenaria 6 Super abundant 41-60 %
Mya arenaria 4 Rare 41-60 %
Pomatoschistus microps 14 Common 41-60 %
Cladophora 1 Rare 21-40 %

Similar biotopes or habitat types

Not applicable or unknown.

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