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.
Filamentous green seaweeds on low salinity infralittoral mixed sediment or rock
Physical habitat description
Salinity | Full (30-35 ppt), Variable (18-35 ppt) |
---|---|
Wave exposure | Extremely sheltered |
Tidal streams | Weak (>1 kn), Very weak (negligible) |
Substratum | Muddy sediment with pebbles & cobbles & boulders |
Zone | Infralittoral |
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.

- 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.
Description
Shallow muddy sediments, often with boulders, cobbles and pebbles around the edges of lagoons, or other areas that are exposed to wide salinity variations are unsuitable for colonisation by many species. Such areas may be colonised by a dense blanket of ephemeral green algae such as Ulva spp., Chaetomorpha linum, Cladophora liniformis or Rhizoclonium riparium. This biotope may also contain some red seaweeds, such as Furcellaria lumbricalis, but always at low abundance (compare with IR.LIR.Lag.ProtFur). Amongst the filamentous green algae, grazing molluscs and solitary ascidians may be present. Infauna may typically include Corophium volutator, Baltidrilus costatus, Tubificoides benedeni and other taxa suited for low/variable salinity environments.
Situation
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 |
---|---|---|---|
Corophium volutator | 56 | Super abundant | 81-100% |
Baltidrilus costatus | 19 | Abundant | 61-80% |
Ulva intestinalis | 18 | Frequent | 21-40% |
Mysidae | 15 | Frequent | 41-60% |
Tubificoides benedii | 12 | Abundant | 61-80% |
Chaetomorpha linum | 9 | Frequent | 21-40% |
Filamentous green algae | 9 | Common | 21-40% |
Hediste diversicolor | 7 | 61-80% | |
Arenicola marina | 5 | Occasional | 21-40% |
Cladophora | 5 | Frequent | 21-40% |
Ulva | 5 | Frequent | 21-40% |
Pygospio elegans | 5 | 61-80% | |
Rhizoclonium riparium | 3 | Frequent | 21-40% |
Gasterosteus aculeatus | 3 | Occasional | 21-40% |
Beggiatoa | 2 | Occasional | 21-40% |
Carcinus maenas | 2 | Occasional | 21-40% |
Corophium volutator | 2 | 1-20% | |
Derbesia marina | 2 | Common | 1-20% |
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.FilG | Filamentous green seaweeds on low salinity infralittoral mixed sediment or rock |
2004 (04.05) | SS.SMp.KSwSS.FilG | Filamentous green seaweeds on low salinity infralittoral mixed sediment or rock |
1997 (97.06) | SS.IMX.KSwMx.FiG | Filamentous green seaweeds on low salinity infralittoral mixed sediment or rock |
1996 (6.95) | SIR.FiG |