Skip to Content

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.

   Sediment-affected or disturbed kelp and seaweed communities

Physical habitat description

Salinity Full (30-35 ppt)
Wave exposure Exposed, Moderately exposed, Sheltered
Tidal streams Moderately strong (1-3 kn), Weak (>1 kn), Very weak (negligible)
Substratum Bedrock; unstable boulders and cobbles: often nearby coarse sediment
Zone Infralittoral
Depth Band 0-5 m, 5-10 m, 10-20 m
Other Features Disturbed or sediment-affected

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 IR.HIR.KSed Sediment-affected or disturbed kelp and seaweed communities

  • 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.


Infralittoral rock habitats, subject to disturbance through mobility of the substratum (boulders or cobbles) or abrasion/covering by nearby coarse sediments or suspended particulate matter (sand). The associated communities can be quite variable in character, depending on the particular conditions, which prevail. The typical Laminaria hyperborea and red seaweed communities of stable open coast rocky habitats (IR.MIR.KR) are replaced by those, which include more ephemeral species or those tolerant of sand and gravel abrasion. As such Saccharina latissima, Saccorhiza polyschides or Halidrys siliquosa may be prominant components of the community.


No situation data available.

Temporal variation

No temporal variation data available.

Characterising species

Taxon Typical abundance - SACFOR scale % of core records where taxon was recorded
Alcyonium digitatum Occasional 21-40%
Asterias rubens Occasional 41-60%
Balanus crenatus Frequent 21-40%
Botryllus schlosseri Occasional 41-60%
Cancer pagurus Occasional 21-40%
Chondrus crispus Occasional 41-60%
Clavelina lepadiformis Occasional 21-40%
Corallina officinalis Occasional 21-40%
Corallinaceae Frequent 41-60%
Cryptopleura ramosa Occasional 41-60%
Delesseria sanguinea Occasional 41-60%
Desmarestia aculeata Occasional 21-40%
Dictyota dichotoma Occasional 41-60%
Dilsea carnosa Occasional 41-60%
Electra pilosa Frequent 21-40%
Halarachnion ligulatum Occasional 21-40%
Halidrys siliquosa Frequent 41-60%
Heterosiphonia plumosa Frequent 41-60%
Hypoglossum hypoglossoides Occasional 41-60%
Laminaria hyperborea Frequent 41-60%
Phycodrys rubens Occasional 21-40%
Plocamium cartilagineum Frequent 61-80%
Rhodomela confervoides Occasional 21-40%
Saccharina latissima Frequent 41-60%
Spirobranchus triqueter Frequent 41-60%
Steromphala cineraria Occasional 41-60%
Urticina felina Occasional 41-60%
Vertebrata byssoides Frequent 41-60%

Similar biotopes or habitat types

Not applicable or unknown.

Classification history of this biotope or habitat type

Classification version Code
1997 (97.06) SedK

Back to top