Hediste diversicolor in Atlantic littoral gravelly muddy sand and gravelly sandy mud
Sheltered gravelly sandy mud, subject to reduced salinity, mainly on the mid and lower shore. The infaunal community is dominated by abundant ragworms Hediste diversicolor. Other species of the infauna vary for the sub-biotopes described. They include polychaetes such as Pygospio elegans, Streblospio shrubsolii, and Manayunkia aestuarina, oligochaetes such as Heterochaeta costata and Tubificoides spp., the mud shrimp Corophium volutator, the spire shell Hydrobia ulvae, the baltic tellin Limecola balthica (Macoma balthica) and the peppery furrow shell Scrobicularia plana. Sub-biotopes described as subunits of this unit have equivalent communities in soft muddy sediments, but the sediment here is much firmer due to the gravel component. There are relatively few records in each sub-type, leading to uncertainty over the precise nature of the habitat, particularly regarding sediment type and salinity regime.
Situation: It is probable that there are broad transition areas between the sub-biotopes of MA4-232and the corresponding muddy sediment biotopes. The boundaries may be very indistinct, with the MA4-232 groups present in patches of gravelly mud on areas of mudflat where the main biotopes are their corresponding mud or sandy mud biotopes. Given the small number of records for each of the sub-biotopes, their spatial distribution is still uncertain.
Source: EUNIS habitat classification
|EUNIS habitat type||code MA4232|
|Relation to||Resolution 4 habitat type (used for designation of Emerald sites)|
Relation to other habitat types mentioned in legal instruments
Relation to vegetation types (syntaxa)Not available
Species mentioned in habitat description
|Species scientific name||English common name||Species group|
|Classification||Code||Habitat type name||Relationship type||Comment|
|EUNIS Habitat Classification 200410||A2.411||Hediste diversicolor in littoral gravelly muddy sand and gravelly sandy mud||same|
|EUNIS Habitat Classification 200410||A2.41||Hediste diversicolor dominated gravelly sandy mud shores||same|
|EUNIS Habitat Classification 200308||A2.41||Sheltered combination sediment shores||wider|
|EUNIS Habitat Classification 200202||A2.41||Sheltered combination sediment shores||wider|
|EUNIS Habitat Classification 199910||A2.43||Sheltered mixed sediment shores||wider|