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
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- Date Issued: 2024-04
Aspects of the ecology and biology of Gilchristella aestuarius (G & T) (Pisces: Clupeidae) in the Swartkops estuary, Port Elizabeth
- Authors: Talbot, Marie Marcel Jean-Francois
- Date: 1982-12
- Subjects: Fishes -- Ecology -- South Africa -- Swartkops River Estuary , Swartkops River Estuary (South Africa)
- Language: English
- Type: Master's theses , Manuscripct
- Identifier: http://hdl.handle.net/10948/52352 , vital:43613
- Description: The Department of Zoology at the University of Port Elizabeth has an ongoing programme on the Swartkops estuary with the eventual aim of drawing up the energy pathways of the system. Marais (1976) has investigated the nutritional ecology of the grunter Pommadasys cormersoni while Melville-Smith (1978) and Melville-Smith and Baird (1981) reported on the ecology of larval fish. Winter (1979) studied the ecological parameters of fish populations, but this work was not a detailed account of each population. Wooldridge (1979) studied components of the 3 zooplankton community in some detail. It became evident that there was a significant lack of understanding of the ecological relationships between plankton and piscivorous fish, which was crucial to the elucidation of the interactions and trophodynamics of the Swartkops estuarine system. Since G. aestuarius is an important link in the energy pathway from the plankton to the nekton, and in terms of numbers dominates the seine net catches made in the estuary (Winter, 1979), this study was motivated. The aim was to investigate the important biological parameters of the estuarine round herring population namely the population structure, distribution and abundance, individual growth rate from field data, the food and feeding habits, reproduction and respiration, all of which are essential for the understanding of the dynamics of a species. These parameters were later converted into energy terms and the construction of an energy budget was attempted. , Thesis (MSc) -- Faculty of Science, 1982
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- Date Issued: 1982-12