[Nephtys cirrosa]-dominated littoral fine sand

Description of [Nephtys cirrosa]-dominated littoral fine sand


flag A2.2313
creatorIdentity remo
creationTime 2017-08-16T16:38:13.052
Last Maintainer Identity remo
modificationTime 2016-03-16T18:42:49
id 2780
imageSize 0 Bytes

This biotope occurs mainly on the mid and lower shore on moderately wave-exposed and sheltered coasts, with medium to fine clean sand which remains damp throughout the tidal cycle and contains little organic matter. The sediment is not usually well sorted and may contain a fraction of coarse sand. It is often rippled and typically lacks an anoxic sub-surface layer. The polychaete infauna is dominated by Nephtys cirrosa, Magelona mirabilis, Spio martinensis, Spiophanes bombyx and Paraonis fulgens. The presence of polychaetes may be seen as coloured burrows running down from the surface of the sediment. Nemertean worms may be present. The amphipods Pontocrates spp. and Bathyporeia spp., as well as Cumopsis goodsiri and the shrimp Crangon crangon are typically present. The bivalve Angulus tenuis is scarce or absent. Situation: This unit may be present higher up on the shore than unit A2.2312, or lower down than A2.2232or A2.2221. Temporal variation: The infaunal community of this biotope may change seasonally, as increased storminess during winter months may reduce sediment stability and the ability of some species to survive. Some species, such as the shrimp C. crangon avoid these conditions by seasonal migration to deeper water (Moore, 1991).