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Show simple item record Lemley, DA Taljaard, Susan Adams, JB Strydom, N 2015-10-22T10:29:09Z 2015-10-22T10:29:09Z 2014-10
dc.identifier.citation Lemley, DA, Taljaard, S, Adams, JB and Strydom, N. 2014. Nutrient characterisation of river inflow into the estuaries of the Gouritz Water Management Area, South Africa. Water SA, Vol 40(4), pp. 687-698 en_US
dc.identifier.issn 0378-4738
dc.description Copyright: 2014. South African Water Research Commision en_US
dc.description.abstract This study provides an overview of the nutrient status of river inflow into the estuaries within the Gouritz Water Management Area (WMA) of South Africa. Riverine inputs are a major source of macronutrients to estuaries and the adjacent coastal environments. Long-term water quality monitoring data (dissolved inorganic nitrogen, i.e. DIN; and dissolved inorganic phosphorus, i.e. DIP), collected by the Department of Water Affairs (DWA), were used to assess historical trends of river nutrient inflow within the Gouritz WMA. The results indicate that DIP concentrations exceeded the eutrophic limits for aquatic ecosystems (DWA) in 50% of the catchments assessed. Anthropogenic activities such as agriculture, wastewater discharge, urbanisation, and afforestation were significant factors influencing nutrient levels within these rivers. For the majority of the river systems (approx. 80%) there was no significant correlation (P > 0.05) between inorganic nutrient levels and freshwater inflow from the catchments. Wastewater treatment plant (WWTP) data (DWA) were assessed to explore the reasons for this ‘disconnect’ between freshwater inflow and inorganic nutrient levels. Results indicate that the Gwaing (267.73 kg·d(sup-1) DIN; 77.46 kg·d(sup-1) DIP), Goukou (49.71 kg·d(sup-1) DIN; 17.38 kg·d(sup-1) DIP), Knysna (41.77 kg·d(sup-1) DIN; 13.92 kg·d(sup-1) DIP) and Hartenbos (37.73 kg·d(sup-1) DIN; 21.39 kg·d(sup-1) DIP) systems received the highest daily loads from WWTPs. The Gwaing and Hartenbos estuaries would be most vulnerable to increased nutrient loading because of their small size and prolonged periods of mouth closure. The study highlights the importance of water quality monitoring of river inflows into coastal ecosystems, as it is needed to assess pollution trends and identify management priorities. en_US
dc.language.iso en en_US
dc.publisher South African Water Research Commision en_US
dc.relation.ispartofseries Workflow;14598
dc.subject Water quality en_US
dc.subject Eutrophication en_US
dc.subject Inorganic nutrients en_US
dc.subject Wastewater discharges en_US
dc.subject Gouritz water management area en_US
dc.title Nutrient characterisation of river inflow into the estuaries of the Gouritz Water Management Area, South Africa en_US
dc.type Article en_US

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