Description of biotope or habitat type
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Polychaete/bivalve-dominated muddy sand shores
Physical habitat description
| Salinity | Full (30-35 ppt), Reduced (18-30ppt), Variable (18-35 ppt) |
|---|---|
| Wave exposure | Moderately exposed, Sheltered, Very sheltered, Extremely sheltered |
| Tidal streams | |
| Substratum | Fine sand or muddy sand |
| Zone | |
| Depth Band | Lower shore, Mid shore, Strandline, Upper shore |
| 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.
- 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'
Point data based on records in the UK Marine Recorder Snapshot.
Description
Muddy sand or fine sand, often occurring as extensive intertidal flats on open coasts and in marine inlets. The sediment generally remains water-saturated during low water. The habitat may be subject to variable salinity conditions in marine inlets. An anoxic layer may be present below 5 cm of the sediment surface, sometimes seen in the worm casts on the surface. The infauna consists of a diverse range of amphipods, polychaetes, bivalves and gastropods.
Situation
Muddy sand communities are found predominantly on the mid and lower shore, though they may span the entire intertidal. Fine sand or mobile sand communities may be present on the upper shore with muddy sand communities present lower down. In sheltered mid estuarine conditions, muddy sand communities may be present on the upper part of the shore with mid estuarine muddy shore communities (MEST) lower down.
Temporal variation
Not known.
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 |
|---|---|---|---|---|
| Macoma balthica | 22 | Common | 786 | 81-100% |
| Pygospio elegans | 15 | Common | 670 | 61-80% |
| Peringia ulvae | 11 | Abundant | 2829 | 41-60% |
| Cerastoderma edule | 10 | Abundant | 504 | 61-80% |
| Oligochaeta | 6 | Abundant | 1703 | 41-60% |
| Eteone longa | 6 | Abundant | 114 | 41-60% |
| Hediste diversicolor | 5 | Common | 229 | 41-60% |
| Bathyporeia pilosa | 3 | Common | 446 | 21-40% |
| Corophium arenarium | 3 | Common | 437 | 21-40% |
| Corophium volutator | 3 | Common | 1074 | 21-40% |
| Scoloplos armiger | 3 | Abundant | 66 | 21-40% |
| Nematoda | 2 | Common | 213 | 21-40% |
| Crangon crangon | 2 | Common | 25 | 21-40% |
| Capitella capitata | 1 | Frequent | 78 | 21-40% |
Similar biotopes or habitat types
Not applicable or unknown.