Description of biotope or habitat type
To understand more about what this page is describing, see How to use the classification. See also How to cite.
Nephtys hombergii and Streblospio shrubsolii in littoral mud
Physical habitat description
| Salinity | Reduced (18-30ppt), Variable (18-35 ppt) |
|---|---|
| Wave exposure | Very sheltered, Extremely sheltered |
| Tidal streams | |
| Substratum | Mud with fine sand fraction |
| 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 wet mud with a fine sand fraction, on the mid and lower shore of sheltered estuaries, usually with an anoxic layer present within the first 5 cm of the sediment. The infauna is relatively poor, dominated by the polychaetes Nephtys hombergii, Streblospio shrubsolii, and Aphelochaeta marioni. The oligochaete Tubificoides benedii is also characterising for this biotope, and Hediste diversicolor may be common.
Situation
NhomStr may occur on the same shores as the MEST biotopes, Hed.Cvol or Hed.Str. Higher up on the shore, and/or further towards the head of the estuary, Hed.Ol may occur, changing to Tben at the upper extreme of the 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 |
|---|---|---|---|---|
| Aphelochaeta marioni | 50 | Abundant | 2790 | 61-80% |
| Streblospio shrubsolii | 23 | Common | 483 | 61-80% |
| Tubificoides benedii | 10 | Common | 1259 | 61-80% |
| Nephtys hombergii | 9 | Common | 108 | 61-80% |
Similar biotopes or habitat types
LS.LMu.UEst.Hed.Ol
Occurs in very similar, but often slightly less saline conditions, further towards the head of estuaries. The species assemblage is poorer, consisting virtually only of oligochaetes and abundant H. diversicolor.
LS.LMu.MEst.NhomMacStr
Tends to occur lower on the shore, in sediments with a greater sand fraction and often subject to more wave exposure, possibly lower down in estuaries. The polychaete assemblage is more diverse, and both Peringia ulvae and Macoma balthica are typically present. It is the presence these two species that primarily distinguishes LS.LMu.MEst.NhomMacStr from similar estuarine mud biotopes.
LS.LMu.UEst.Hed.Str
Tends to occur in slightly less saline, more sheltered conditions, with a higher abundance of H. diversicolor and a greater range of polychaete and oligochaete species. A. marioni is absent.
LS.LMu.MEst.HedMacScr
Occurs over a greater range of shore heights, often on slightly less exposed shores, with an increased infaunal diversity. H. diversicolor is more abundant, and, most notably, the bivalves M. balthica and Scrobicularia plana are abundant.
LS.LMu.UEst.Hed.Cvol
Occurs on slightly more exposed shores, with a reduced infaunal diversity. H. diversicolor and Corophium volutator are the only characterising species.Classification history of this biotope or habitat type
| Classification version | Code |
|---|---|
| 1997 (97.06) | LMU.MU.HedStr (part) |