UKZN 2 UWC 3. MACE Lab

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1 S. Pillay 1;3, Dr. A. J. Smit 2, Dr D. Robertson-Andersson 1;3 1 UKZN 2 UWC 3 MACE Lab

2 Objectives The specific objectives were: (1) To determine if each estuary chosen for this study is eutrophic and comparisons made with the current known health status (2) To determine the effect of season on nitrogen pollution in rocky shores during the closed and open phase of the estuary (3) To determine if the level of nitrogen pollution changes with increasing distance away from the estuary.

3 Table 1. Ranking of esturine state based on functionng and health of the system (adapted from Forbes & Demetriades (2008)) Health state of estuary Excellent Good Fair Poor Mhlungwa (Hibberdene) Highly degraded Mtamvuna (Port Edward) Kongweni (Margate) Description Estuaries with high water quality, level of habitat integrity are high, high diversity and high provision of goods and services. Estuaries with most of the core estuarine habitat and estuarine support habitats still present, good water quality, diversity of habitats and species and estuarine processes in place. Estuaries with core estuarine habitat intact, some estuarine support habitats, impacted water quality and some loss of diversity and key estuarine process in place. Estuaries with impacted core estuarine habitat. Substantially reduced or no estuarine support habitats, polluted water, substantial loss of diversity and/or abundance and key estuarine processes impaired. Estuaries which have had major impacts on core estuarine habitats through infilling, canalisation and pollution, substantially reduced or no estuarine support habitats and major loss of key estuarine processes.

4 Hibberdene (Mhlungwa Estuary) Margate (Kongweni Estuary with WWTP) Port Edward (Umtamvuna Estuary) Sampling Mouth: POM DIN δ15n (POM) Chl a 2000 m 1000 m 600 m 200 m 100 m δ15n of Macroalgae Figure 2. sampling plan for each site

5 Estuary Results Figure 2 Level of nutrient pollution in each of the estuaries in Hibberdene (Mhlungwa), Margate (Kongweni) and Port Edward (Umtamvuna)

6 Rocky Shores Figure 5. 2 Level of nitrogen pollution distributed across stations in Hibberdene (Mhlungwa), Margate (Kongweni) and Port Edward (Umtamvuna)

7 Overall outcomes and recommendations Nitrogen pollution is evident among the sites concerned It is suggested that both the estuary and rocky shore habitat be monitored to elucidate other factors not considered here. The condition of sites chosen for this study clearly indicate a need for mitigation of nutrient pollution in estuaries and a greater need for development of WWTW along the coast of KZN. A survey of the KZN coastline will give an indication of those similarly impacted and in need of mitigation

8 Thank you

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Introduction to protection goals, ecosystem services and roles of risk management and risk assessment. Lorraine Maltby

Introduction to protection goals, ecosystem services and roles of risk management and risk assessment. Lorraine Maltby Problem formulation Risk assessment Risk management Robust and efficient environmental