Coastal and near-shore changes correlated with die-back in eel-grass (Zostera Marina,L.)

The die-back of eel-grass (Zostera marina, L.) is found to have played an important role with regard to near-shore sedimentation and coastal changes.In a natural harbour at Kyholm, Denmark a hiatus is found between silty sediments that date from about 4000 BC and overlying modern sandy sediments. It is suggested that this is a consequence of the die-back of eel-grass in the nineteen-thirties, resulting in mobilisation and disturbance of nearshore sediments and the shoreward movement of mobilised sandy material into the harbour. The coastal morphology of Kyholm was relatively stable from 1802 to 1933, but between 1933 and 1978 there have been two periods of drastic progradation correlated with die-back of eel-grass.