Description of biotope or habitat type
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Ulothrix flacca and Urospora spp. on freshwater-influenced vertical littoral fringe soft rock
Physical habitat description
| Salinity | Full (30-35 ppt) |
|---|---|
| Wave exposure | Moderately exposed |
| Tidal streams | |
| Substratum | Bedrock |
| Zone | Littoral fringe |
| Depth Band | |
| Other Features | Vertical soft rock |
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'
Point data based on records in the UK Marine Recorder Snapshot.
Description
An assemblage of the small un-branched filamentous green seaweeds Ulothrix flacca, Urospora penicilliformis and Urospora wormskioldii at High Water Spring Tide level on steep and vertical rock often influenced by freshwater. The community is also present in areas with freshwater seepage. It is visually recognised as a closely adherent, often shiny, green mat of filamentous growth. Associated species include the green seaweeds Blidingia minima and Ulva prolifera, the barnacle Semibalanus balanoides and the limpet Patella vulgata, but these species are not common. Although this biotope does occur on rock other than chalk, this description has been derived from chalk coast sites. More information is needed to improve this description.
Situation
On chalk coasts this community can include Ulva spp. and the transition from UloUro to Ulv is often indistinct and a mixed zone of UloUro and Ulv can occur.
Temporal variation
This biotope is more easily identifiable from autumn to spring as both Urospora spp. and Bangia atropurpurea may dry out and disappear during the summer. In late winter the red seaweed B. atropurpurea may be predominant and the community then appears as shiny blackish mats of filamentous growth.
Characterising species
| Taxon | Relative importance of taxon for defining this community (%) | Typical abundance - SACFOR scale | % of core records where taxon was recorded |
|---|---|---|---|
| Ulothrix | 36 | Occasional | 81-100% |
| Ulva | 34 | Rare | 81-100% |
| Urospora wormskioldii | 9 | Frequent | 61-80% |
| Semibalanus balanoides | 7 | 61-80% | |
| Patella vulgata | 7 | 61-80% | |
| Polydora | 7 | Occasional | 61-80% |
| Ulothrix flacca | 1 | 21-40% | |
| Urospora penicilliformis | 1 | 21-40% |
Similar biotopes or habitat types
LR.FLR.Lic.Bli
Vertical soft rock in the littoral fringe characterised by a band of the foliose green seaweeds B. minima and Blidingia marginata. The filamentous, un-branched green seaweeds U. flacca and Urospora spp. may be present in this biotpe.
LR.FLR.Eph.Ulv
Occurs on the lower shore and is characterised by Ulva sp.Classification history of this biotope or habitat type
| Classification version | Code |
|---|---|
| 1995 | LRK.UU |
