Description of biotope or habitat type
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Fucus spiralis on full salinity upper eulittoral mixed substrata
Physical habitat description
| Salinity | Full (30-35 ppt) |
|---|---|
| Wave exposure | Exposed, Moderately exposed, Sheltered |
| Tidal streams | |
| Substratum | Mixed substrata |
| Zone | Eulittoral - upper |
| 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
Moderately exposed to sheltered full salinity upper eulittoral mixed substrata characterised by a band of the wrack Fucus spiralis. Occasional clumps of the wrack Pelvetia canaliculata can be overgrowing the black lichen Verrucaria maura and the olive green lichen Verrucaria mucosa. On the more stable boulders underneath the fronds the red crust Hildenbrandia rubra can be found along with the barnacle Semibalanus balanoides and the limpet Patella vulgata. The winkles Littorina littorea and Littorina saxatilis can be found on and among the boulders and cobbles, while amphipods and the crab Carcinus maenas can be present either underneath the boulders or among the brown seaweeds. The green seaweed Ulva intestinalis can occur in some abundance especially during the summer.
Situation
This zone usually lies below a zone dominated by the wrack P. canaliculata (PelB; Pel). Vertical surfaces in this zone, especially on moderately exposed shores, often lack the fucoids and are characterised by a barnacle-limpet dominated community (Sem).In areas of extreme shelter, such as in Scottish sea lochs, the P. canaliculata and F. spiralis zones often merge together forming a very narrow band. Fspi.X occur above the wracks Ascophyllum nodosum (Asc.X) and/or Fucus vesiculosus (Fves.X) zones. These two fucoids may also occur among the F. spiralis, although F. spiralis always dominates. Fspi.X can also be found above a barnacle S. balanoides and winkle L. littorea dominated biotope (BLitX).
Temporal variation
Ephemeral green seaweeds such as E. intestinalis can occur in some abundance during the summer when the growth conditions are optimal.
Characterising species
| Taxon | Relative importance of taxon for defining this community (%) | Typical abundance - SACFOR scale | % of core records where taxon was recorded |
|---|---|---|---|
| Fucus spiralis | 42 | Common | 81-100% |
| Littorina saxatilis | 12 | Frequent | 61-80% |
| Semibalanus balanoides | 5 | Occasional | 41-60% |
| Patella vulgata | 5 | Occasional | 41-60% |
| Verrucaria maura | 3 | Frequent | 21-40% |
| Amphipoda | 3 | Frequent | 21-40% |
| Littorina littorea | 3 | Frequent | 21-40% |
| Ulva intestinalis | 2 | Occasional | 21-40% |
| Hildenbrandia rubra | 2 | Occasional | 21-40% |
| Pelvetia canaliculata | 2 | Occasional | 21-40% |
| Verrucaria mucosa | 1 | Frequent | 21-40% |
| Ascophyllum nodosum | 1 | Occasional | 21-40% |
| Carcinus maenas | 1 | Occasional | 21-40% |
Similar biotopes or habitat types
LR.LLR.F.Fspi.FS
Occurs in moderately exposed conditions on rock. It has a similar species composition, though amphipods, the crab C. maenas and the whelk Nucella lapillus is usually absent.
LR.LLR.FVS.FspiVS
Occurs in sheltered areas with variable salinity. The species diversity is lower and the species P. vulgata and M. edulis are absent. The barnacle Austrominius modestus can be present.Classification history of this biotope or habitat type
| Classification version | Code |
|---|---|
| 1997 (97.06) | SLR.Fspi (part) |
| 1995 | LRK.FSP |
