Description of biotope or habitat type
To understand more about what this page is describing, see How to use the classification. See also How to cite.
Oligochaetes in variable salinity littoral mobile sand
Physical habitat description
| Salinity | Variable (18-35 ppt) |
|---|---|
| Wave exposure | Extremely sheltered |
| Tidal streams | Weak (>1 kn) |
| Substratum | Pebble, gravel, sand |
| Zone | |
| Depth Band | Lower shore, Mid shore, Upper 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
A species-poor community of oligochaetes occurring in estuarine conditions where sands and gravel are associated with the lower shore river channel in estuaries. The sediment is relatively coarse and mobile due to strong river flow and subject to variable salinity. There is usually very little mud in the sediment. Oligochaetes, including enchytraeid oligochaetes, constitute the infaunal assemblage. Nemerteans may be present, and nematodes may be frequent.
Situation
Ol.VS occurs in channels of very fast flowing river mouths at the bottom of otherwise sheltered estuarine shores. In this situation, biotopes under the MEST and UEST biotope complexes may be present above the river channel. Tal may be found on the upper shore where driftlines of decomposing seaweed and other debris accumulate.
Temporal variation
Not known.
Characterising species
| Taxon | Relative importance of taxon for defining this community (%) | Typical abundance - SACFOR scale | Typical abundance - (count per m2) | % of core records where taxon was recorded |
|---|---|---|---|---|
| Oligochaeta | 70 | Abundant | 2045 | 61-80% |
| Nemertea | 10 | 280 | 21-40% | |
| Enchytraeidae | 6 | Common | 389 | 21-40% |
| Nematoda | 5 | Frequent | 37 | 21-40% |
Similar biotopes or habitat types
LS.LMu.UEst.Tben
Occurs on upper estuarine muddy shores where there is no strong river flow, and hence the sediment is very soft. While the physical environment is very different, the infaunal community is similarly poor. It consists of oligochaetes, including Tubificoides benedii and Baltidrilus costatus, as well as the polychaete Capitella capitata.Classification history of this biotope or habitat type
| Classification version | Code |
|---|---|
| 1997 (97.06) | LGS.Est.Ol |
