Atlantic abyssal coarse sediment

Description (English)

Deep-sea coarse sediment has not been sampled widely for infauna so little is currently known about infaunal community structure. Epifauna tend to be sparse mobile species or burrowing fauna such as anemones visible at the surface. In the absence of ecological data, coarse sediment habitat can be defined according to Long (2006), which describes the classification's broad sediment types according to the relative proportion of mud, sand and gravel (see p3 of UKSeaMap 2010 technical report 3 http://jncc.defra.gov.uk/pdf/UKSeaMap2010_TechnicalReport_3_Substrate2.pdf). It can be difficult to reliably distinguish between coarse sediment and mixed sediment using video data only. Note that mixed sediment has a greater mud content than coarse sediment. If sediment particles are large enough to be classed as gravel using the Folk classification then sediment would be classed as coarse sediment rather than sand. If sand contains a high enough percentage of gravel it is also classed as coarse sediment. Coral rubble is classed as coarse sediment. Stable pebbles, cobbles and boulders are classed as rock; any rock present on coarse sediment is considered a separate habitat within a mosaic.

Source: EUNIS habitat classification