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Marine Habitat Classification

Description of biotope or habitat type

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   Saccharina latissima and Chorda filum on sheltered upper infralittoral muddy sediment

Physical habitat description

Salinity Full (30-35 ppt)
Wave exposure Moderately exposed, Sheltered, Very sheltered, Extremely sheltered
Tidal streams Moderately strong (1-3 kn), Weak (>1 kn)
Substratum Muddy sand and pebbles
Zone Infralittoral - upper, Sublittoral fringe
Depth Band 0-5 m, 5-10 m
Other Features

Biotope origin

Derived using data from Various
Faunal group Epifauna

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 SS.SMp.KSwSS.SlatCho <I>Saccharina latissima</I> and <I>Chorda filum</I> on sheltered upper infralittoral muddy sediment

  • 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'
  • Predicted extent of the level 3 (for sublittoral rock & deep sea) or 4 (for sublittoral sediment) habitat

Point data based on records in the UK Marine Recorder Snapshot. Predicted habitat extent is from UKSeaMap.


Shallow kelp community found on sandy mud and gravelly sandy mud, in sheltered or extremely sheltered conditions, with very weak tidal currents. The community is characterised by a reasonable covering of Saccharina latissima and Chorda filum. Beneath the kelp canopy, Ulva lactuca is often frequent and some filamentous and foliose red algae may be present, along with filamentous brown ectocarpoid algae although in much lower abundance than in the SS.SMp.KSwSS.SlatR biotopes. At the sediment surface ubiquitous fauna such as Asterias rubens, crabs such as Pagurus bernhardus, Carcinus maenas, and the gastropod Steromphala cineraria may be visible and in some areas Sabella pavonina may be present. Given the nature of the sediment it is likely that a wide range of infaunal bivalves and polychaetes are present including Arenicola marina, Mediomastus fragilis and Phyllodoce mucosa. In more tide swept areas with coarser and generally less muddy sediments SS.SMp.KSwSS.SlatCho may be replaced by one of the SS.SMp.KSwSS.SlatR biotopes.


No situation data available.

Temporal variation

No temporal data available.

Characterising species

Taxon Relative importance of taxon for defining this community (%) Typical abundance - SACFOR scale % of core records where taxon was recorded
Phyllodoce mucosa 50 81-100%
Mediomastus fragilis 50 81-100%
Saccharina latissima 23 Frequent 81-100%
Chorda filum 18 Frequent 81-100%
Carcinus maenas 9 Occasional 61-80%
Arenicola marina 5 Frequent 41-60%
Pagurus bernhardus 5 Occasional 41-60%
Asterias rubens 4 Occasional 41-60%
Hydractinia echinata 3 Occasional 41-60%
Ulva 3 Occasional 21-40%
Ascidiella aspersa 2 Frequent 21-40%
Buccinum undatum 2 Occasional 21-40%
Steromphala cineraria 2 Occasional 21-40%
Liocarcinus depurator 2 Occasional 21-40%
Polyides rotunda 2 Occasional 21-40%
Balanus crenatus 1 Occasional 21-40%

Similar biotopes or habitat types

Not applicable or unknown.

Classification history of this biotope or habitat type

Classification version Code Habitat name
2015 (15.03) SS.SMp.KSwSS.LsacCho Laminaria saccharina and Chorda filum on sheltered upper infralittoral muddy sediment
2004 (04.05) SS.SMp.KSwSS.LsacCho Laminaria saccharina and Chorda filum on sheltered upper infralittoral muddy sediment
1997 (97.06) Part of SS.IMX.KSwMx.LsacX Laminaria saccharina, Chorda filum and filamentous red seaweeds on sheltered infralittoral sediment

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