Amphipods and Scolelepis spp. In Atlantic littoral medium-fine sand
|EUNIS habitat type||code MA5233|
|Relation to||Resolution 4 habitat type (used for designation of Emerald sites)|
Mobile clean sandy beaches on exposed and moderately exposed shores, with sediment grain sizes ranging from medium to fine, often with a fraction of coarser sediment. The sediment contains little or no organic matter, and usually no anoxic layer is present at all. It tends to be well-drained, retaining little water at low tide, though the sediment of the MA5-2333 sub-unit may remain damp throughout the tidal cycle. These beaches usually occur under fully marine conditions, though the MA5-2332 sub-unit may occur under moderately exposed lower estuarine conditions. The mobility of the sediment leads to a species-poor community, dominated by polychaetes, isopods and burrowing amphipods. Scolelepis spp. can tolerate well-drained conditions, and are often present in well-draining, coarser sand. Burrowing amphipods that often occur in this biotope include Bathyporeia spp., Pontocrates arenarius, and Haustorius arenarius. The isopod Eurydice pulchra is also often present. On semi-exposed beaches with a moderate tide range where there is a marked high-shore berm, there can be a marked seepage at the foot of the berm that probably carries the products of the organic matter derived from strand line breakdown. Here in a narrow zone, exceptionally high populations of Bathyporeia pilosa, sometimes above 10000 per square metre, may occur. The zone may be narrower than the strandline and could easily be missed on surveys were only a few levels are sampled. Three sub-biotopes are described for this biotope, based principally on differences in infaunal species composition.
Situation: Situated mainly on the mid and lower shore, sometimes upper shore, of exposed to moderately exposed beaches. Under more exposed conditions, it may occur below MA5-231, or MA3-211. Under more sheltered conditions, it may occur above the communities of unit MA5-241. Unit MA5-211 may be present on the same shores as MA5-233 where driftlines of decomposing seaweed and other debris occur on the upper shore.
Temporal variation: Winter storms may reduce the number of or temporarily remove macroinvertebrates from exposed sandy beaches, with the sediment becoming re-colonised during the summer months.
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)||A2.223||Amphipods and Scolelepis spp. in littoral medium-fine sand||same|
|Classification||Code||Habitat type name||Relationship type||Comment|
|EUNIS Habitat Classification 200410||A2.223||Amphipods and Scolelepis spp. in littoral medium-fine sand||same|
|EUNIS Habitat Classification 200202||A2.244||Burrowing amphipods and polychaetes in clean sand shores||same|
|EUNIS Habitat Classification 199910||A2.214||Burrowing amphipods and polychaetes in clean sand shores||same|
|MNCR BioMar 97.06 (Britain & Ireland)||LGS.S.AP||Burrowing amphipods and polychaetes in clean sand shores||same|