Biodiversity & Conservation

For a full description of this biotope including characterizing species, distribution, survey information and references visit JNCC

Circalittoral fine sandy mud and shelly gravel may contain Virgularia mirabilis and Ophiura spp. Such sediments are very common in sea lochs, often occurring shallower than the finest mud or in somewhat more exposed parts of the lochs. A variety of species may occur, and species composition at a particular site may relate, to some extent, to the proportions of the major sediment size fractions. Greater quantities of stones and shells on the surface may give rise to more sessile epibenthic species (CMS.VirOph.HAs). Several species are common to most sites including Virgularia mirabilis which is present in moderate numbers, Ophiura albida and Ophiura ophiura which are often quite common, and Pecten maximus which is usually only present in low numbers. Inachus dorsettensis, Aporrhais pespelecani, Pagurus prideaux and Astropecten irregularis, although less widespread, are typical species of this sediment type. Virgularia mirabilis is usually accompanied by Cerianthus lloydii, Chaetopterus variopedatus, terebellids, including Lanice conchilega and, less commonly, Arenicola marina and Myxicola infundibulum in this biotope. Amphiura chiajei and Amphiura filiformis occur in high densities in the sandier examples of this biotope but are uncommon in the more gravelly muds. Polychaetes and bivalves are the main components of the infauna, although nemerteans, Edwardsia claparedii, Phoronis muelleri and Labidoplax buski are also widespread. Of the polychaetes Goniada maculata, Nephtys incisa, Minuspio cirrifera, Chaetozone setosa, Notomastus latericeus and Owenia fusiformis are the most widespread species. Myrtea spinifera, Lucinoma borealis, Mysella bidentata, Abra alba and Corbula gibba were common bivalves in this sediment type. Turritella communis may form dense aggregations at sandier sites. (Information taken from the Marine Biotope Classification for Britain and Ireland, Version 97.06: Connor et al., 1997a, b).