Description of biotope or habitat type
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Sublittoral mixed sediment in variable salinity (estuaries)
Physical habitat description
| Salinity | Variable (18-35 ppt) |
|---|---|
| Wave exposure | Sheltered, Very sheltered, Extremely sheltered |
| Tidal streams | Moderately strong (1-3 kn), Weak (>1 kn), Very weak (negligible) |
| Substratum | Muddy gravelly mixed sediment with stones and shells |
| Zone | Infralittoral |
| Depth Band | 0-5 m, 5-10 m |
| Other Features |
Biotope origin
| Derived using data from | Various |
| Faunal group | Epifauna/infauna |
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.
- 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.
Description
Shallow sublittoral mixed sediments in estuarine conditions, often with surface shells or stones, enabling the development of diverse epifaunal communities, e.g. Crepidula fornicata (SS.SMx.SMxVS.CreMed), as well as infaunal communities. This biotope complex is therefore often quite species rich, compared with purer sediments.
Situation
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 |
|---|---|---|---|
| Crepidula fornicata | 58 | Frequent | 61-80% |
| Aphelochaeta marioni | 22 | Common | 61-80% |
| Cardiidae | 20 | 21-40% | |
| Cirripedia | 7 | Common | 21-40% |
| Carcinus maenas | 7 | Occasional | 21-40% |
| Mediomastus fragilis | 6 | Frequent | 61-80% |
| Nephtys hombergii | 6 | Common | 61-80% |
| Crepidula fornicata | 5 | Abundant | 61-80% |
| Polydora ciliata | 5 | Abundant | 41-60% |
| Chaetozone zetlandica | 3 | Common | 21-40% |
| Tubificoides benedii | 3 | Common | 41-60% |
| Exogone naidina | 2 | Frequent | 41-60% |
| Melinna palmata | 2 | Common | 41-60% |
| Scoloplos armiger | 2 | Common | 41-60% |
| Sphaerosyllis | 2 | Frequent | 21-40% |
| Abra alba | 1 | Common | 21-40% |
| Abra nitida | 1 | Common | 21-40% |
| Capitella capitata | 1 | Frequent | 41-60% |
| Eteone longa | 1 | 41-60% | |
| Lepidonotus squamatus | 1 | 41-60% | |
| Tubificoides | 1 | Frequent | 21-40% |
| Tubificoides swirencoides | 1 | Common | 21-40% |
Similar biotopes or habitat types
Not applicable or unknown.
Classification history of this biotope or habitat type
| Classification version | Code | Habitat name |
|---|---|---|
| 2015 (15.03) | SS.SMx.SMxVS | Sublittoral mixed sediment in variable salinity (estuaries) |
| 2004 (04.05) | SS.SMx.SMxVS | Sublittoral mixed sediment in variable salinity (estuaries) |
| 1997 (97.06) | SS.IMX.EstMx | Estuarine sublittoral mixed sediments |