Description of biotope or habitat type
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Polyides rotunda and/or Furcellaria lumbricalis on reduced salinity infralittoral rock
Physical habitat description
| Salinity | Reduced (18-30ppt), Low (<18ppt) |
|---|---|
| Wave exposure | Very sheltered, Extremely sheltered |
| Tidal streams | Very weak (negligible) |
| Substratum | Bedrock; boulders, cobbles and pebbles |
| Zone | Infralittoral |
| Depth Band | 0-5 m |
| 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.
- 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
Bedrock and boulders characterised by a dense turf of the red seaweeds Polyides rotunda and/or Furcellaria lumbricalis, often with a dense mat of filamentous brown and green seaweeds including Ectocarpaceae and Cladophora spp. Other red seaweeds presents include Chondrus crispus, Gracilaria gracilis and coralline crusts as well as the odd brown seaweed Chorda filum or Laminaria spp. Associated with these seaweeds are a variety of ascidians including Clavelina lepadiformis, Ascidiella aspersa, Ascidiella scabra and Ciona intestinalis as well as the anemones Anemonia viridis and Actinia equina and the sponge Halichondria panicea. More mobile fauna include the starfish Asterias rubens, the crab Carcinus maenas, the hermit crab Pagurus bernhardus, the opossum shrimps Mysidae and the gastropod Littorina littorea. Attached to the rock or cobbles are spirorbid polychaetes and the mussel Mytilus edulis. Please notice that part of this diversity is due to large differences between sites.
Situation
Nearby rock (AscSpAs and FChoG) and seagrass Ruppia maritima dominating much of the surrounding muddy sediment (Rup). Mixed sediment supports filamentous green seaweeds e.g. Cladophora spp. and Derbesia marina on (FiG).
Temporal variation
Unknown.
Characterising species
| Taxon | Relative importance of taxon for defining this community (%) | Typical abundance - SACFOR scale | % of core records where taxon was recorded |
|---|---|---|---|
| Furcellaria lumbricalis | 11 | Common | 41-60% |
| Polyides rotunda | 10 | Common | 41-60% |
| Asterias rubens | 7 | Occasional | 61-80% |
| Corallinaceae | 6 | Occasional | 61-80% |
| Carcinus maenas | 6 | Frequent | 41-60% |
| Mysidae | 5 | Occasional | 41-60% |
| Ascidiella aspersa | 5 | Frequent | 41-60% |
| Chorda filum | 5 | Frequent | 41-60% |
| Ciona intestinalis | 5 | Frequent | 41-60% |
| Ectocarpaceae | 3 | Occasional | 21-40% |
| Ulva | 3 | Occasional | 41-60% |
| Spirorbinae | 3 | Frequent | 21-40% |
| Actinia equina | 2 | Occasional | 21-40% |
| Anemonia viridis | 2 | Frequent | 21-40% |
| Chondrus crispus | 2 | Occasional | 21-40% |
| Cladophora | 2 | Frequent | 21-40% |
| Cladophora rupestris | 2 | Occasional | 21-40% |
| Clavelina lepadiformis | 2 | Frequent | 21-40% |
| Ascidiella scabra | 1 | Occasional | 21-40% |
| Gracilaria gracilis | 1 | Frequent | 21-40% |
| Halichondria panicea | 1 | Occasional | 21-40% |
| Littorina littorea | 1 | Frequent | 21-40% |
| Mytilus edulis | 1 | Frequent | 21-40% |
| Pagurus bernhardus | 1 | Frequent | 21-40% |
| Laminaria | 1 | Frequent | 21-40% |
Similar biotopes or habitat types
Not applicable or unknown.
Classification history of this biotope or habitat type
| Classification version | Code |
|---|---|
| 2015 (15.03) | IR.LIR.Lag.ProtFur |
| 1997 (97.06) | SLR.PolFur |