Cohesive sandy mud, sometimes with a small quantity of shell in shallow water may contain the bivalves Mysella bidentata and Abra spp. (typically A. alba and A. nitida). Other characteristic taxa may include Scoloplos armiger, Mya sp., and Thyasira flexuosa. Tube building amphipods are also characteristic of this biotope in particular Ampelisca spp. and Aoridae such as Microprotopus maculatus. Situation: This biotope is generally found in sheltered marine inlets or sealochs such as Strangford Lough.