Shores of coarse sediments (shingle, gravels and coarse sand) in the upper reaches of estuaries and other inlets (e.g. sealochs) which are subject to variable and reduced salinity conditions. The outflow of riverine freshwater at the heads of the inlets results in the washing out of fine particulate matter, leaving coarse sediments. These are typically species-poor and characterised by oligochaete worms (cf. A2.222).