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Marine Habitat Classification

Description of biotope or habitat type

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   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
Zone Infralittoral
Depth Band 0-5 m, 5-10 m
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.

Distribution of habitat SS.SCS.ICS.CumCset Cumaceans and <I>Chaetozone setosa</I> in infralittoral gravelly sand

  • 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.


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.

Temporal variation

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.

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
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 %

Similar biotopes or habitat types

In more exposed areas CumCset may grade into Glap as fewer species are able to tolerate the more frequent sediment disturbance

In areas of weaker current and/or wave action the sediment becomes more stable and CumCset may grade into AalbNuc

In areas of weaker current and / or wave action as sediment stability increases CumCset may grade into FfabMag.

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