An Ecophysiological Study of the Meiofauna of the Swartkops Estuary

Abstract

As part of a larger project, a number of physical and chemical features of two beaches in the Swartkops Estuary near Port Elizabeth were monitored over a period of fourteen months. These features included temperature, nitrogen, chlorophyll a, oxygen and salinity. In addition measurements were made of particle size, porosity, permeability and desiccation. It was found that environmental conditions were most severe at the higher tidal levels as well as in the upper reaches of the estuary. Nitrogen and chlorophyll a varied greatly from month to month and the usefulness of such determinations as indicators of available food is questioned. The interstitial environment was found to be greatly influenced by the presence of sand prawns (Callianassa kraussi). It is suggested that burrowing macrofauna, particularly those forms with burrows extending from the surface, have profound effects on the physical and chemical conditions in beaches and mud flats.