Polychaetes in Atlantic littoral fine sand
|EUNIS habitat type||code MA5241|
|Relation to||Resolution 4 habitat type (used for designation of Emerald sites)|
Moderately exposed or sheltered beaches of medium and fine, usually clean, sand, though the sediment may on rare occasions contain a small silt and clay fraction. The sediment is relatively stable, remains damp throughout the tidal cycle, and contains little organic matter. It is often rippled and typically lacks an anoxic sub-surface layer. Where an anoxic layer is present, it occurs at a depth below 10 cm and tends to be patchy. The biotope occurs mainly on the lower part of the shore, and relatively frequently on the mid shore. It is only rarely present above mid shore level, except where coastal defences cause backwash onto the upper shore. Conditions are usually fully marine, though the biotope can also occur in open lower estuarine conditions. The infaunal community is dominated by a range of polychaete species such as Nephtys cirrosa, Paraonis fulgens, Spio spp., Pygospio elegans, Ophelia rathkei and Scoloplos armiger. The presence of polychaetes may be seen as coloured burrows running down from the surface of the sediment, and Arenicola marina casts may be present on the sediment surface. The amphipods Bathyporeia spp. and Pontocrates arenarius frequently occur, and nemerteans are often present. On some North Wales shores, the presence of Arenicola species characterises the lowest part of the shore, with a range of species characteristic of the shallow sublittoral. These include sparsely distributed Echinocardium, Amphiura brachiata, Ensis siliqua and Fabulina fabula. This biotope is split into three sub-biotopes, between which there can be a large degree of overlap. The bivalve Angulus tenuis dominates the MA5-2412 sub-biotope, which is characterised by slightly more stable and fine sediments than the other two sub-biotopes.
Situation: This unit may be present below the communities of units MA5-233 or MA5-2321 on moderately exposed shores. MA5-231 may occur on the upper part of the shore if it is subject to drying in between tides. The strandline biotope MA5-211 may be present on the same shore where driftlines of decomposing seaweed and other debris occur on the upper shore.
Temporal variation: The infauna of this biotope may be affected significantly by seasonal changes in degree of wave exposure. During stormy winters, the sediment may become de-stabilised, leading to the disappearance of some macroinfaunal species. The lugworm A. marina may be present occasionally, usually as a temporary recruitment and is likely to be washed out during storms.
Source: EUNIS habitat classification
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|
|EUNIS Habitat Classification 2007 (revised descriptions 2012)||A2.231||Polychaetes in littoral fine sand||same|
|Classification||Code||Habitat type name||Relationship type||Comment|
|EUNIS Habitat Classification 200410||A2.231||Polychaetes in littoral fine sand||same|
|EUNIS Habitat Classification 200308||A2.2441||Polychaetes in littoral fine sand||same|
|EUNIS Habitat Classification 200202||A2.2441||Burrowing amphipods and polychaetes (often with Arenicola marina) in clean sand shores||same|
|EUNIS Habitat Classification 199910||A2.2141||Burrowing amphipods and polychaetes (often with Arenicola marina) in clean sand shores||same|
|MNCR BioMar 97.06 (Britain & Ireland)||LGS.S.AP.P||Burrowing amphipods and polychaetes (often with Arenicola marina) in clean sand shores||same|