Blankets of fucoid seaweeds dominating sheltered to extremely sheltered rocky shores with variable salinity. The wrack Pelvetia canaliculata (A1.321) occurs on the upper shore, with the wrack Fucus spiralis (A1.322) below. The middle shore is dominated by vast areas of the wrack Ascophyllum nodosum or the wrack Fucus vesiculosus (A1.323, A1.324) or a mixture of both. The wrack Fucus serratus covers lower shore bedrock and boulders (A1.326). Fucus ceranoides can be found on extremly sheltered shores with variable or low salinity (A1.327). The variable salinity communities are species impoverished compared to fucoids in full salinity or in tide-swept conditions as red seaweeds and sponges are usually absent. Underneath the canopy are a few green seaweeds including Enteromorpha intestinalis and Cladophora spp., while the red seaweed Polysiphonia lanosa can be found as an epiphyte on A. nodosum. On the rock and among the boulders are the winkles Littorina littorea and Littorina saxatilis, the crab Carcinus maenas, the barnacles Semibalanus balanoides and Elminius modestus and even the occasional mussel Mytilus edulis. Situation: On sheltered eulittoral rocky shores with variable salinity conditions, such as sea loch or estuaries.