Description of biotope or habitat type
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Fucoids in tide-swept conditions
Physical habitat description
| Salinity | Full (30-35 ppt), Variable (18-35 ppt) |
|---|---|
| Wave exposure | Sheltered, Very sheltered, Extremely sheltered |
| Tidal streams | Very strong (>6 kn), Strong (3-6 kn), Moderately strong (1-3 kn) |
| Substratum | Bedrock, stable boulders, cobbles |
| Zone | |
| Depth Band | Lower shore, Mid shore |
| 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
Biotope complex description Fucoid seaweeds in tide-swept conditions on sheltered to extremely sheltered mid eulittoral to lower eulittoral rocky shores, such as narrow channels in sea lochs. The middle shore can be dominated by the wrack Ascophyllum nodosum (AscT), while Fucus serratus is dominating the lower shore (FserT, FserTX). The high levels of water movement encourages a rich associated fauna including several filter-feeding groups. These include the sponges Grantia compressa, Halichondria panicea and Hymeniacidon perlevis which frequently occur on steep and overhanging faces of boulders and bedrock. It also includes the sea squirts Dendrodoa grossularia and Ascidiella scabra, which occur on steep surfaces and beneath boulders. Hydroids such as the pink Clava multicornis can form colonies on A. nodosum while Dynamena pumila is more often found on Fucus vesiculosus or F. serratus. Underneath the canopy formed by the brown seaweeds is a diverse community of the red seaweeds Gelidium pusillum, Chondrus crispus, Lomentaria articulata, Membranoptera alata and coralline crusts, but the green seaweeds Ulva intestinalis, Ulva lactuca and Cladophora rupestris can be present. The filamentous red seaweed Vertebrata lanosa can usually be found growing on A. nodosum. On the rock beneath are the limpet Patella vulgata and the barnacle Semibalanus balanoides, while the crab Carcinus maenas and a variety of winkles including Littorina littorea, Littorina fabalis and Littorina obtusata can be found on or among the boulders. The whelk Nucella lapillus can either be found in cracks and crevices.
Situation
Sheltered tide-swept shores (i.e. estuaries and sea lochs) below the Fucus spiralis and F. vesiculosus band and above the kelp dominated zone in the sublittoral.
Temporal variation
No temporal variation data available.
Characterising species
| Taxon | Relative importance of taxon for defining this community (%) | Typical abundance - SACFOR scale | % of core records where taxon was recorded |
|---|---|---|---|
| Fucus serratus | 10 | Common | 81-100% |
| Ascophyllum nodosum | 6 | Abundant | 41-60% |
| Corallinaceae | 5 | Frequent | 61-80% |
| Dynamena pumila | 5 | Frequent | 61-80% |
| Littorina | 5 | Occasional | 61-80% |
| Patella vulgata | 5 | Occasional | 61-80% |
| Ulva intestinalis | 4 | Occasional | 61-80% |
| Halichondria panicea | 4 | Occasional | 61-80% |
| Ulva lactuca | 4 | Occasional | 61-80% |
| Nucella lapillus | 4 | Occasional | 61-80% |
| Semibalanus balanoides | 3 | Frequent | 41-60% |
| Carcinus maenas | 3 | Occasional | 41-60% |
| Chondrus crispus | 3 | Frequent | 41-60% |
| Mastocarpus stellatus | 3 | Frequent | 41-60% |
| Cladophora rupestris | 2 | Frequent | 21-40% |
| Dendrodoa grossularia | 2 | Frequent | 41-60% |
| Steromphala cineraria | 2 | Frequent | 41-60% |
| Hymeniacidon perlevis | 2 | Occasional | 41-60% |
| Littorina littorea | 2 | Occasional | 41-60% |
| Lomentaria articulata | 2 | Occasional | 41-60% |
| Vertebrata lanosa | 2 | Frequent | 21-40% |
| Spirobranchus triqueter | 2 | Occasional | 41-60% |
| Spirorbinae | 2 | Frequent | 21-40% |
| Fucus vesiculosus | 2 | Occasional | 41-60% |
| Mytilus edulis | 1 | Occasional | 21-40% |
Similar biotopes or habitat types
Not applicable or unknown.