PLANKTON DISTRIBUTION AND ABUNDANCE IN THE SUNDAYS RIVER ESTUARY, SOUTH-AFRICA, WITH COMMENTS ON POTENTIAL FEEDING INTERACTIONS

Three mysid and three calanoid copepod species dominated the mesozoopl ankton in the Sundays River estuary, South Africa. Mid estuary, there was considerable overlap in the spatial and temporal distribution of s pecies. Mesozooplankton abundance was lowest during winter. Microzoopl ankton, consisting of ciliates, zooflagellates and rotifers, was most abundant in the middle of the estuary. Rotifer abundance was lowest in winter and autumn. Other microzooplankton showed no seasonal variatio n. Phytoplankton was dominated by micro- and nanoflagellates, dinoflag ellates and euglenoids, but diatoms were very abundant after a flood. Chlorophyll a concentrations were greatest in the middle and upper est uary, but there they showed no seasonal fluctuations.