Browsing by Author "Allanson, Brian"

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    The role of water column and benthic communities in the spatial and temporal production and uptake of nutrients in controlling the trophic status of the Knysna River Estuary, South Africa
    (2003) Switzer, Todd Brent; Allanson, Brian; Waldron, Howard
    The Knysna Estuary is the largest estuarine ecosystem in the warm temperate coastal region of South Africa. The estuary remains oligotrophic (chlorophyll-a < 5 mg l-1) despite increases in anthropogenic input of nitrogen and phosphate associated with the rapidly increasing urbanization of its littoral and catchment. This dissertation relies on original data, which includes the measuring of concentrations of ammonium, nitrates (nitrate and nitrite), dissolved inorganic phosphate and urea in the water column quarterly for one year at 21 stations. It estimates the contribution to these nutrients from rivers, storm drains and rainfall entering the estuary during this year by monitoring concentration and flow in these source waters. Seasonal, tidal and post-flood patterns of nutrient concentration in the water column are assessed with respect to nutrient loading to determine if variations in concentration are the result of loading or processes in the estuary.