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 |
Biotope origin
| Derived using data from | Various |
| Faunal group | 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, muddy mixed sediments in areas of low or reduced, although stable, salinity (may vary annually) with largely ephemeral faunal communities. Characterised by infaunal oligochaetes, including Baltidrilus costatus and Enchytraeidae, polychaetes such as Hediste diversicolor, Polydora ciliata and Pygospio elegans, bivalves such as Mya arenaria, Abra tenuis, and the lagoon cockle Cerastoderma glaucum as well as surface dwelling snails including Peringia ulvae. Other infauna can vary but can include very high numbers of amphipods Aoridae, Monocorophium insidiosum and other Corophium species, isopods Idotea spp. and seasonally occurring Chironomid larvae. Some sites with higher organic content also have very high numbers of Tubificoides oligochaetes and to a lesser extent Capitella capitata.
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 |
|---|---|---|---|
| Enchytraeidae | 34 | Abundant | 61-80% |
| Hediste diversicolor | 31 | Frequent | 81-100% |
| Hediste diversicolor | 25 | Super abundant | 61-80% |
| Baltidrilus costatus | 20 | Abundant | 61-80% |
| Baltidrilus costatus | 17 | Frequent | 61-80% |
| Chironomidae | 16 | Occasional | 61-80% |
| Pomatoschistus microps | 14 | Common | 41-60% |
| Mya arenaria | 6 | Super abundant | 41-60% |
| Cerastoderma glaucum | 6 | Common | 21-40% |
| Pygospio elegans | 5 | Common | 41-60% |
| Peringia ulvae | 4 | Common | 41-60% |
| Mya arenaria | 4 | Rare | 41-60% |
| Palaemon varians | 3 | Occasional | 21-40% |
| Polydora ciliata | 3 | Abundant | 41-60% |
| Cerastoderma glaucum | 3 | Common | 41-60% |
| Lekanesphaera hookeri | 2 | Occasional | 21-40% |
| Neomysis integer | 2 | Rare | 21-40% |
| Alkmaria romijni | 2 | Rare | 21-40% |
| Peringia ulvae | 1 | Rare | 21-40% |
| Cladophora | 1 | Rare | 21-40% |
| Corophium volutator | 1 | 41-60% |
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.SMxLS | Sublittoral mixed sediment in low or reduced salinity (lagoons) |
| 2004 (04.05) | SS.SMx.SMxLS | Sublittoral mixed sediment in low or reduced salinity (lagoons) |