Description of biotope or habitat type
Polydora ciliata and Corophium volutator in variable salinity infralittoral firm mud or clay
Habitat (physical) description
|Salinity||Variable (18-35 ppt)|
|Wave exposure||Sheltered, Very sheltered, Extremely sheltered|
|Tidal streams||Weak (>1 kn)|
|Substratum||Hard clay, relict peat, mud with fine sand fraction|
|Depth Band||0-5 m, 5-10 m|
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
Variable salinity clay and firm mud characterised by a turf of the polychaete Polydora ciliata along with the amphipod Corophium volutator. Other important taxa include the polychaetes Pygospio elegans, Hediste diversicolor, Streblospio shrubsolii and the oligochaete Tubificoides benedii. P. ciliata also occurs in high densities elsewhere (see MCR.Pol) and may be a specific feature of the Humber Estuary in these conditions. This biotope occurs only in very firm mud and clay and possibly submerged relict saltmarsh with a high detrital content. It is characterised, and can be separated from other biotopes, by a combination of the sediment characteristics and the very high density of Polydora ciliata. In some areas, such as the Humber estuary, cyclical behaviour with regard its characteristic taxa has been reported with either P. ciliata or C. volutator increasing in dominance at the expense of the other (Gameson 1982). It is possible that changes in water quality or the sediment regime may be responsible for this.
No situation data available.
No temporal data available.
|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|
|Eteone longa||2||Common||32||41-60 %|
|Hediste diversicolor||5||Common||84||61-80 %|
|Polydora ciliata||43||Abundant||6407||81-100 %|
|Pygospio elegans||9||Frequent||152||61-80 %|
|Streblospio shrubsolii||6||Common||642||41-60 %|
|Tubificoides benedii||4||Frequent||616||61-80 %|
|Tubificoides pseudogaster||2||Abundant||2850||21-40 %|
|Gammarus salinus||1||Common||6||21-40 %|
|Corophium volutator||21||Common||556||61-80 %|
|Hydrobia ulvae||1||Common||332||21-40 %|