Comparing stable isotope ratios and metal concentrations between components of the benthic food web: a case study of the Swartkops Estuary South Africa
- Authors: Ndoto, Asiphe
- Date: 2024-04
- Subjects: Swartkops River Estuary (South Africa) , Estuarine ecology -- South Africa -- Swartkops River Estuary , Fishes -- Ecology -- South Africa -- Swartkops River Estuary
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/64256 , vital:73669
- Description: Estuarine systems are highly productive ecosystems; however, they are subjected to high anthropogenic pressure such as metal contamination and: increased nutrient loads. The contamination sources of metals and nutrients in urban estuaries are derived: from industrial waste. agricultural and urban runoff that flows into estuaries. An example of such a system is the Swartkops Estuary. industry and three wastewater treatment plants within the Swartkops River catchment are major sources of metal. and nutrient pollution, respectively. The metals accumulate in the environment, are biomagnified up the food web, and transferred from one trophic level to another. At lethal concentrations, metals pose a threat to organisms using the estuary by affecting their physiological and biochemical processes. Stable Isotope analysis has proven to be an effective tool for investigating, trophic linkages in the food chain from a variety of environments. By assessing both metals and stable _isotopes in the. estuary it can provide a more robust understanding of the pathway metals accumulate, biomagnified, and transfer from the environment through the estuarine food web. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2022
- Full Text:
- Date Issued: 2024-04
- Authors: Ndoto, Asiphe
- Date: 2024-04
- Subjects: Swartkops River Estuary (South Africa) , Estuarine ecology -- South Africa -- Swartkops River Estuary , Fishes -- Ecology -- South Africa -- Swartkops River Estuary
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/64256 , vital:73669
- Description: Estuarine systems are highly productive ecosystems; however, they are subjected to high anthropogenic pressure such as metal contamination and: increased nutrient loads. The contamination sources of metals and nutrients in urban estuaries are derived: from industrial waste. agricultural and urban runoff that flows into estuaries. An example of such a system is the Swartkops Estuary. industry and three wastewater treatment plants within the Swartkops River catchment are major sources of metal. and nutrient pollution, respectively. The metals accumulate in the environment, are biomagnified up the food web, and transferred from one trophic level to another. At lethal concentrations, metals pose a threat to organisms using the estuary by affecting their physiological and biochemical processes. Stable Isotope analysis has proven to be an effective tool for investigating, trophic linkages in the food chain from a variety of environments. By assessing both metals and stable _isotopes in the. estuary it can provide a more robust understanding of the pathway metals accumulate, biomagnified, and transfer from the environment through the estuarine food web. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2022
- Full Text:
- Date Issued: 2024-04
Developing a socio- ecological framework for the restoration of estuaries using the Swartkops Estuary as a case study
- Authors: Tsipa, Vusumzi
- Date: 2022-04
- Subjects: Estuarine ecology -- South Africa -- Swartkops River Estuary , Ecosystem
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/59622 , vital:62208
- Description: The aim of this study was to develop and test a socio-ecological systems framework for the restoration of estuaries in South Africa using the Swartkops Estuary as a case study. This necessitated a review of existing SES frameworks that have been developed for use in other disciplines. As part of the newly developed framework, the Swartkops estuary condition was assessed using the Estuary Health Index to understand the present ecological state (PES) of the estuary following from the last assessment done in 2013/2014. The Estuary Health Index is a nationally accepted method of measuring the health of South African estuaries. The state of the societal system was assessed through field observations, engagements with estuary users on-site, insights provided by the Zwartkops Conservancy, and from recent literature. The potential for restoration of habitats for the purpose of carbon storage was also assessed as part of this study. The suitability of disturbed habitats for stimulating future salt marsh growth was investigated since an important incentive for restoration is blue carbon storage. This is important as blue carbon ecosystems offer great potential as a climate change mitigation measure through their ability to sequester carbon. This was done by evaluating plant cover and sediment characteristics at sites along the length of the estuary representing disturbed and undisturbed areas. The estuarine health score for the Swartkops Estuary was found to be 47 out of 100 translating to a PES Category D (largely modified estuary). The main problem in the estuary is water quality along with habitat loss and resource exploitation. The three Wastewater Treatment Works (WWTWs) located upstream of the estuary are the main drivers behind the decline in estuary health in addition to other threats to the water quality which are stormwater run-off inputs from the Motherwell canal and Markman canal. This study showed that the health of the estuary is on a negative trajectory towards a largely degraded estuary. Fishing, bait collection and the use of spiritual sites are the dominant vii ecosystem services used at the estuary. Through the assessment of the state of the societal system, the estuary was highlighted to be a major food source for many people living close to the estuary through subsistence fishing and bait collection for selling to recreational fishers. The estuary is also a health hazard to the very same people that depend on it for survival because of the poor water quality particularly high metal inputs from past and present nearby industrial activities. Restoration plans need to be developed in consideration of the estuary status quo that includes the societal system and the ecosystem services provided by the estuary. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Tsipa, Vusumzi
- Date: 2022-04
- Subjects: Estuarine ecology -- South Africa -- Swartkops River Estuary , Ecosystem
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/59622 , vital:62208
- Description: The aim of this study was to develop and test a socio-ecological systems framework for the restoration of estuaries in South Africa using the Swartkops Estuary as a case study. This necessitated a review of existing SES frameworks that have been developed for use in other disciplines. As part of the newly developed framework, the Swartkops estuary condition was assessed using the Estuary Health Index to understand the present ecological state (PES) of the estuary following from the last assessment done in 2013/2014. The Estuary Health Index is a nationally accepted method of measuring the health of South African estuaries. The state of the societal system was assessed through field observations, engagements with estuary users on-site, insights provided by the Zwartkops Conservancy, and from recent literature. The potential for restoration of habitats for the purpose of carbon storage was also assessed as part of this study. The suitability of disturbed habitats for stimulating future salt marsh growth was investigated since an important incentive for restoration is blue carbon storage. This is important as blue carbon ecosystems offer great potential as a climate change mitigation measure through their ability to sequester carbon. This was done by evaluating plant cover and sediment characteristics at sites along the length of the estuary representing disturbed and undisturbed areas. The estuarine health score for the Swartkops Estuary was found to be 47 out of 100 translating to a PES Category D (largely modified estuary). The main problem in the estuary is water quality along with habitat loss and resource exploitation. The three Wastewater Treatment Works (WWTWs) located upstream of the estuary are the main drivers behind the decline in estuary health in addition to other threats to the water quality which are stormwater run-off inputs from the Motherwell canal and Markman canal. This study showed that the health of the estuary is on a negative trajectory towards a largely degraded estuary. Fishing, bait collection and the use of spiritual sites are the dominant vii ecosystem services used at the estuary. Through the assessment of the state of the societal system, the estuary was highlighted to be a major food source for many people living close to the estuary through subsistence fishing and bait collection for selling to recreational fishers. The estuary is also a health hazard to the very same people that depend on it for survival because of the poor water quality particularly high metal inputs from past and present nearby industrial activities. Restoration plans need to be developed in consideration of the estuary status quo that includes the societal system and the ecosystem services provided by the estuary. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2022
- Full Text:
- Date Issued: 2022-04
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