Oligochaetes in full salinity Atlantic littoral mobile sand

Description (English)

A species-poor community of oligochaetes occurring in fully marine conditions on open shores with mobile, medium to fine, usually clean, sand. Oligochaetes, including enchytraeid oligochaetes, constitute the infaunal assemblage. On rare occasions individuals of polychaete or crustacean species may be encountered (e.g. Nephtys spp., Eurydice pulchra, Bathyporeia spp.), though these are not characterising for the biotope and if present in any significant abundance, the area should be classed as unit MA5-233.
Situation: Where MA5-2321 is situated on the mid shore, MA3-211 and/or MA5-231 may be present on the upper shore, and lower down on the shore, MA5-2331 and MA5-2333 may be found. MA6-2273 may also occur on the upper shore, with MA5-2332 present on the mid shore, and MA5-2411 or MA5-2412 on the lower shore. MA5-211 may be found on the upper shore where driftlines of decomposing seaweed and other debris accumulate.
Temporal variation: Wave exposure may be higher on some beaches during winter than during the summer months, leading to the disappearance of infaunal species in winter. Where this happens, the biotope may change to MA5-231. If conditions become more sheltered, seasonally or permanently, the sediment may become colonised by a greater range of species and the area may change to MA5-233.

Source: EUNIS habitat classification