Description of biotope or habitat type
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Mytilus edulis beds on reduced salinity infralittoral rock
Physical habitat description
| Salinity | Reduced (18-30ppt), Low (<18ppt) |
|---|---|
| Wave exposure | Very sheltered, Extremely sheltered |
| Tidal streams | Strong (3-6 kn), Moderately strong (1-3 kn), Weak (>1 kn) |
| Substratum | Bedrock; boulders |
| Zone | Infralittoral |
| Depth Band | 0-5 m |
| Other Features | May occur on vertical 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'
- 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
This biotope occur in shallow, often tide-swept, reduced salinity conditions. Dense beds of the mussel Mytilus edulis with the occasional barnacle Balanus crenatus. A wide variety of epifaunal colonisers on the mussel valves, including seaweeds, hydroids and bryozoans can be present. Predatory starfish Asterias rubens can be very common in this biotope. This biotope generally appears to lack large kelp plants, although transitional examples containing mussels and kelps plants may also occur. More information needed to validate this description.
Situation
Occurs in tide-swept entrance channels in very enclosed basins of sealochs where the basins are typically of lowered salinity. Also occurs in very sheltered subtidal rock (often vertical) in lagoons.
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 |
|---|---|---|---|
| Balanus crenatus | 85 | Common | 81-100% |
| Mytilus edulis | 9 | Abundant | 81-100% |
| Asterias rubens | 1 | Frequent | 81-100% |
Similar biotopes or habitat types
Not applicable or unknown.