The interaction between the dunes systems and the lower estuary at the Bushmans River Mouth, Eastern Cape over the past 60Â years

The morphology of estuary mouths along the Eastern Cape coast changes from year to year and season to season due to natural actions of migrating aeolian dunes, floods and tidal action. However, the Bushmans River Mouth has changed dramatically over the last 60 to 70 years, perceivably in an irreversible manner. An account of these changes has been documented from studies of aerial photographs dating back to the 1940s. A study of the dynamics and functions of the coastal dune system on the east bank of the Bushmans River Mouth was conducted in 2003. Surveys of the dunefield describe the sedimentological processes leading to the build-up and migration of a mobile dune. It was found that the factors affecting aeolian accretion at the site are topography, river mouth configuration, dune types and the presence of vegetation as well as the seasonal wind regime. A vegetation survey along transects on the east bank dunefield showed a successional change of plant communities from salt marsh, through dune pioneer, open scrub, closed scrub to a scrub-thicket community. Proposals for the management of the estuary/river mouth/dunefield system have been promulgated to enhance the future recreational use of the estuary mouth area.