Description of biotope or habitat type
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Beggiatoa spp. on anoxic sublittoral mud
Physical habitat description
| Salinity | Full (30-35 ppt), Variable (18-35 ppt) |
|---|---|
| Wave exposure | Sheltered, Very sheltered, Extremely sheltered |
| Tidal streams | Weak (>1 kn), Very weak (negligible) |
| Substratum | Mud |
| Zone | Infralittoral |
| Depth Band | 0-5 m, 5-10 m, 10-20 m |
| Other Features | Anoxic |
Biotope origin
| Derived using data from | Various |
| Faunal group | Epifauna |
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
Sublittoral soft anoxic mud, often in areas with poor water exchange with the open sea, can have a conspicuous bacterial mat covering of Beggiatoa spp. The anoxia may be a result of natural conditions of poor water exchange in some sea lochs (and many Scandinavian fjords) or artificially under fish farm cages from nutrient enrichment. The fauna is normally impoverished at such sites, with few elements of the infaunal communities present in other muddy biotopes. Scavenging species such as Asterias rubens and Carcinus maenas are typically present where the habitat is not too anoxic along with occasional Arenicola marina but in extreme conditions of anoxia little survives other than the Beggiatoa. The polychaete Oxydromus flexuosus occurs in high densities at the interface between oxygenated and deoxygenated sediments (in Norwegian fjords).
Situation
No situation data available.
Temporal variation
No temporal data available.
Characterising species
| Taxon | Relative importance of taxon for defining this community (%) | Typical abundance - SACFOR scale | % of core records where taxon was recorded |
|---|---|---|---|
| Beggiatoa | 75 | 81-100% | |
| Carcinus maenas | 18 | 41-60% | |
| Polychaeta | 2 | 1-20% | |
| Asterias rubens | 1 | Occasional | 21-40% |
Similar biotopes or habitat types
Not applicable or unknown.
Classification history of this biotope or habitat type
| Classification version | Code | Habitat name |
|---|---|---|
| 2015 (15.03) | SS.SMu.IFiMu.Beg | Beggiatoa spp. on anoxic sublittoral mud |
| 2004 (04.05) | SS.SMu.IFiMu.Beg | Beggiatoa spp. on anoxic sublittoral mud |
| 1997 (97.06) | SS.CMU.Beg | Beggiatoa spp. on anoxic sublittoral mud |