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Marine Habitat Classification

Description of biotope or habitat type

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   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
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.

Distribution of habitat LS.LMu.UEst.NhomStr <I>Nephtys hombergii</I> and <I>Streblospio shrubsolii</I> in littoral mud

  • 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.


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.


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

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.

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.

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.

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.

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)

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