Erosion of an intertidal mussel bed by ice- and wave-action

摘要: The persistence of intertidal mussel beds is governed by both biotic and abiotic processes. Many studies have shown that waves currents are able to erode mussels from an bed, but here it demonstrated in temperate regions ice action can be important as well. These findings result a 27-month-long monitoring campaign on mature bed the Dutch Wadden Sea. Daily camera observations revealed two periods which significant erosion occurred. first event occurred period during was covered ice. Ice resulted initial decrease 19% area around station. losses were concentrated three hotspots largest located close beds’ edge. Around these hotspots, up 0.3 m high ridges piled had formed, with highest westward gaps. observed topographic changes support view mechanism damaged was, at least partly, due physical disturbance scouring Recovery cover limited 19 months following event. Due sedimentation reorganization mussels, relief inside reduced again spread out over larger area. Height differences between uncovered parts increased areas. Wave storm caused further reduction cover. Especially areas previously elevated suffered large losses. multiple wind events, causing initially small gaps expand outward increase extent. results suggest twofold impact wave cover: firstly, directly eroding beds; secondly, indirectly increasing exposure induced shear stresses.