Conservation issues relating to maerl beds as habitats for molluscs

Abstract

Maerl beds are little studied shallow marine habitats that have a patchy distribution around the British Isles. They are mixed sediment deposits built by a surface layer of slow growing coralline seaweeds that are of international conservation significance. Baseline information is provided on the high diversity and abundance of mollusc assemblages associated with Scottish maerl deposits. Commercial extraction and the use of towed demersal fishing gears kills the plants upon which survival of this habitat depends. The molluscan fauna of a site impacted by scallop dredging is compared with that of an unimpacted site. The need to conserve maerl habitats is highlighted as there is concern over the extent to which maerl beds are being disturbed in Europe and how activities such as scallop dredging affect the ecology of these fragile nearshore habitats.