Description of biotope or habitat type
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Nephtys hombergii, Macoma balthica and Streblospio shrubsolii in littoral sandy mud
Physical habitat description
| Salinity | Variable (18-35 ppt) |
|---|---|
| Wave exposure | Sheltered, Very sheltered, Extremely sheltered |
| Tidal streams | |
| Substratum | Sandy mud |
| Zone | |
| Depth Band | Lower shore, Mid 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
Soft mud with a fine sand fraction, in variable salinity conditions, typically close to the head of estuaries. The infauna is dominated by the polychaete worm Streblospio shrubsolii, the polychaete Nephtys hombergii, oligochaetes of the genus Tubificoides, and the Baltic tellin Macoma balthica. The ragworm Hediste diversicolor and the spire shell Peringia ulvae are often common or abundant.
Situation
NhomMacStr occurs in mid estuary conditions, usually on the low shore. Tben and Hed.Ol may occur higher up the shore, as well as further towards the upper estuary.
Temporal variation
Enteromorpha spp. and Ulva lactuca may form mats on the surface of the mud during the summer months, particularly in areas of nutrient enrichment.
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 |
|---|---|---|---|---|
| Peringia ulvae | 43 | Abundant | 5093 | 81-100% |
| Streblospio shrubsolii | 13 | Common | 593 | 81-100% |
| Macoma balthica | 12 | Common | 373 | 81-100% |
| Tubificoides | 12 | Common | 662 | 41-60% |
| Tubificoides benedii | 10 | Common | 999 | 81-100% |
| Nephtys hombergii | 6 | Abundant | 133 | 61-80% |
| Hediste diversicolor | 1 | Common | 124 | 41-60% |
Similar biotopes or habitat types
LS.LMu.UEst.Tben
Occurs in lower salinities, in mud with a smaller sand fraction, at the head of estuaries. The infauna is a lot poorer, consisting almost exclusively of oligochaetes and, in some cases, Capitella capitata.
LS.LMu.UEst.Hed.Ol
Tends to occur in more reduced salinities, further towards the head of estuaries. The polychaete assemblage is poorer, and molluscs are virtually absent. It is the presence of M. balthica and H. ulvae that primarily distinguishes LS.LMu.MEst.NhomMacStr from LS.LMu.UEst.Hed.Ol.
LS.LMu.MEst.HedMac
These communities occur further down estuaries towards the open coast, in more saline conditions. The infauna is similar, though the ragworm H. diversicolor is always abundant, and both N. hombergii and S. shrubsolii are often absent. The bivalve assemblage tends to be more diverse.Classification history of this biotope or habitat type
| Classification version | Code |
|---|---|
| 2015 (15.03) | LS.LMu.MEst.NhomMacStr |
| 1997 (97.06) | LMU.MU.HedStr (part) |