Atlantic infralittoral mud

Shallow sublittoral muds, extending from the extreme lower shore to about 15-20 m depth in fully marine or near marine conditions, predominantly in extremely sheltered areas with very weak tidal currents. Such habitats are found in sealochs and some rias and harbours. $$$Infralittoral, cohesive sandy mud, typically with over 20% silt/clay, have a rich variety of polychaetes including Melinna palmate, tube building amphipods (Ampelisca spp.) and deposit feeding bivalves such as Limecola balthica (Macoma balthica) and Mysella bidentata. Sea pens such as Virgularia mirabilis and brittlestars such as Amphiura spp. may be present but not in the same abundances as found in deeper circalittoral waters. $$$Mud with minimal sand content have populations of the lugworm Arenicola marina may be dense, with anemones, the opisthobranch Philine aperta and synaptid holothurians also characteristic in some areas. The extent of the oxidised layer may be shallow with some areas being periodically or permanently anoxic. In these areas bacterial mats may develop on the sediment surface. Infaunal records for this biotope complex are limited encompassing only one biotope. They are therefore not representative of the full suit of infaunal species found in this biotope.

Código Eunis 2021: MB62