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Marine Habitat Classification

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.


Physical habitat description

Salinity Full (30-35 ppt), Reduced (18-30ppt), Variable (18-35 ppt)
Wave exposure Sheltered, Very sheltered, Extremely sheltered
Tidal streams
Substratum Sandy or muddy sediments
Zone Littoral fringe
Depth Band 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.

Distribution of habitat LS.LMp.Sm Saltmarsh

  • 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.


Angiosperm-dominated stands of vegetation, occurring on the extreme upper shore of sheltered coasts and periodically covered by spring high tides. The vegetation develops on a variety of sandy and muddy sediment types and may have admixtures of coarser material. The character of the saltmarsh communities is affected by height up the shore, resulting in a zonation pattern related to the degree or frequency of immersion in seawater. Saltmarsh vegetation is generally well studied; its classification is fully covered by the UK National Vegetation Classification, where 26 types are defined (Rodwell, 2000). The species listed below give a general indication of the infaunal component of saltmarsh communities. Users are referred to the chapter on saltmarsh communities in Rodwell (2000) for details on the plant communities which characterise the different saltmarsh biotopes.


On the upper shore above sheltered sand, muddy sand, mud, and more marine biotopes. Saltmarshes are generally confined to estuaries and other sheltered marine inlets.

Temporal variation

Saltmarsh vegetation tends to die back during the winter season due to cold temperatures and increased storminess, and saltmarshes may increase in area during the growing period in summer. This is particularly the case for the Salicornia spp. - dominated pioneer saltmarsh communities at the lower end of the saltmarsh zone.

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
Enchytraeidae 53 Common 728 41-60%
Hediste diversicolor 19 Abundant 110 21-40%
Corophium volutator 18 Abundant 165 41-60%
Peringia ulvae 4 Common 603 21-40%
Manayunkia aestuarina 3 Frequent 333 21-40%

Similar biotopes or habitat types

Not applicable or unknown.

Classification history of this biotope or habitat type

Classification version Code
1997 (97.06) LMU.SM


LS.LMP.Sm Saltmarsh, Blakeney Eye, Norfolk. Steve Morris© JNCC
LS.LMP.Sm Saltmarsh, Blakeney Eye, Norfolk. Steve Morris© JNCC

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