Description of biotope or habitat type
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Fucus ceranoides on reduced salinity eulittoral rock
Physical habitat description
| Salinity | Reduced (18-30ppt), Variable (18-35 ppt) |
|---|---|
| Wave exposure | Very sheltered, Extremely sheltered |
| Tidal streams | |
| Substratum | Bedrock; boulders |
| Zone | Eulittoral - upper, Littoral fringe |
| Depth Band | |
| 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'
Point data based on records in the UK Marine Recorder Snapshot.
Description
Very sheltered to extremely sheltered bedrock and stable boulders in the eulittoral zone that are subject to reduced salinity and characterised by the wrack Fucus ceranoides. Species richness is typically low in this biotope. The green seaweeds Ulva intestinalis and Ulva lactuca may be present together with the crab Carcinus maenas and the occasional barnacle Austrominius modestus and Semibalanus balanoides.
Situation
As F. ceranoides is more tolerant of reduced salinity than the other fucoids, F. ceranoides tends to replace the wracks Fucus spiralis, Fucus vesiculosus and Ascophyllum nodosum towards the upper reaches of estuaries and sea lochs or in areas with freshwater influence. This biotope may, however, still contain other fucoids, although F. ceranoides always dominates. This biotope is often found on artificial substrata such as sea defences or bridge supports.
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 |
|---|---|---|---|
| Fucus ceranoides | 66 | Common | 81-100% |
| Ulva intestinalis | 13 | Frequent | 41-60% |
| Carcinus maenas | 4 | Occasional | 41-60% |
| Austrominius modestus | 3 | Occasional | 21-40% |
| Semibalanus balanoides | 2 | Occasional | 21-40% |
| Ulva lactuca | 2 | Occasional | 21-40% |
Similar biotopes or habitat types
Not applicable or unknown.
Classification history of this biotope or habitat type
| Classification version | Code |
|---|---|
| 1997 (97.06) | SLR.Fcer |
| 1997 (97.06) | SLR.FcerX |
| 1995 | LRK.FCER |
Photos
