An Estimate of Shore Ice Action in a Spartina Tidal Marsh, St. Lawrence Estuary, Quebec, Canada
Keywords:Tidal marsh, shore ice, erosion, sedimentation, marsh clumps, St. Lawrence estuary
Measurements made in a Spartina alterniflora tidal marsh along the St. Lawrence estuary provide a rough estimate of the role of shore ice in tidal marsh development in a periglacial region. Marsh clumps torn out and moved by ice floes and subsequently released throughout the marsh surface give a minimum value for the volume of debris removed annually by ice. In nine sample plots surveyed at Isle Verte, clumps released in the marsh by ice floes upon melting cover 0.9 to 16.5% of the area investigated, whereas the volume of clumps ranges from 1.9 to 99.6 cubic meters. Ice-borne clumps represent an important component of the sedimentary budget.