Description of biotope or habitat type
Cumaceans and Chaetozone setosa in infralittoral gravelly sand
Physical habitat description
|Salinity||Full (30-35 ppt)|
|Wave exposure||Moderately exposed|
|Tidal streams||Moderately strong (1-3 kn)|
|Substratum||Medium to very fine sand with gravel and pebbles|
|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
In shallow medium-fine sands with gravel, on moderately exposed open coasts, communities dominated by cumacean crustaceans such as Iphinoe trispinosa and Diastylis bradyi along with the cirratulid polychaete Chaetozone setosa (agg.) may occur. Chaetozone setosa is a species complex so it is likely that some variability in nomenclature will be found in the literature. Other important taxa may include the polychaetes Anaitides spp., Lanice conchilega, Eteone longa and Scoloplos armiger. This community may be subject to periodical sedimentary disturbance, such that a sub-climactic community may develop with opportunistic taxa such as C. setosa and S. armiger often dominating the community (Allen 2000).
This biotope may be found in areas with moderate currents and wave action often facing into the prevailing wind and along the Holderness coast of the North Sea. It is possible that this biotope has developed due to chronic sedimentary disturbance in areas where the biotopes AalbNuc or FfabMag would normally develop as these biotopes are often found in more sheltered areas adjacent to CumCset.
The importance of the cumacean crustaceans in this biotope is unusual, and their numbers are likely to fluctuate over time; at times of increased disturbance it is likely that C. setosa will become more dominant.
|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||3||17||61-80 %|
|Anaitides maculata||4||Common||25||61-80 %|
|Nephtys hombergii||2||Common||18||41-60 %|
|Scoloplos armiger||3||Abundant||32||61-80 %|
|Spio martinensis||3||Frequent||33||41-60 %|
|Chaetozone setosa||22||Abundant||324||81-100 %|
|Lanice conchilega||4||Common||22||61-80 %|
|Iphinoe trispinosa||35||Frequent||151||81-100 %|
|Diastylis bradyi||8||Common||39||61-80 %|
|Nucula nitidosa||2||Frequent||37||41-60 %|
|Ensis ensis||3||23||61-80 %|
|Mya arenaria||1||22||21-40 %|
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