Marine benthic (epilithic) diatom communities along the coast of South Africa: A contribution to their diversity, spatio-temporal variations, and ecology
- Authors: Cotiyane-Pondo, Phumlile
- Date: 2023-12
- Subjects: Marine ecology , Marine biodiversity , Coastal ecology
- Language: English
- Type: Doctorate Dissertation , text
- Identifier: http://hdl.handle.net/10948/62453 , vital:72754
- Description: Diatoms remain one of the most diverse and ecologically important microorganisms within microphytobenthos. The highly variable South African coastline, comprised of heterogeneous rocky intertidal habitats provides the ideal study area to investigate epilithic microphytobenthos and their associated influential drivers. In South Africa, in-depth taxonomic research on marine littoral diatoms exists, however, quantitative research and knowledge on their abundance, diversity, community composition and distribution remain limited. Thus, the main aim of this research was to explore the spatial and temporal variability of marine benthic (epilithic) diatoms, in relation to the variable physico-chemical conditions in the nearshore intertidal environments along the coastline of South Africa. To achieve this, field-based observational (natural substrata) and experimental (artificial substrata) studies were conducted on selected locations around the coastline, with a large focus on south coast localities. For the Spatial studies, large (i.e., encompassing all three biogeographical regions) and small-scale (i.e., coastal island in the warm temperate region) surveys of epilithic diatom assemblages from natural rocky substrata were conducted. Large-scale investigation results revealed highly variable diatom assemblages, diversity and distribution, with compositional differences observed between the coastal sections (around the coastline). A total of 85 diatom taxa from 31 genera were observed at 15 sites, and the number of taxa varied un-systematically along coastline. Genera with noticeable contribution included Nitzschia, Cocconeis and Achnanthes. On the coastal Bird Island (small-scale), similar variability was observed, but with a much higher diatom diversity and number of rarely observed species (e.g. Actinoptychus senarius (Ehrenberg) Ehrenberg, Cocconeis capensis (Cholnoky) Witkowski, Fragilariopsis kerguelensis (O’Meara) Hustedt, Striatella unipunctata (Lyngbye) Agardh. Seventy-two (72) species from 35 genera were recorded with a varied abundance and diversity around the island. The study also revealed a high contribution of typical benthic diatom species to the surf zone environment around the island. To study temporal variations, medium-term compositional differences on natural substrata were assessed monthly over an annual cycle at a single site. A paucity of diatom material was evident during this study and observations indicated a trend of presence and absence of diatom taxa from the study site. Nineteen (19) diatom genera were identified and those observed, albeit as one or two individual valves, included taxa from several genera including Biddulphia, Diploneis, Campyloneis, Trachyneis and Triceratium. Noteworthy was a seasonal increase in the number of diatom valves encountered, with the highest diatom abundance observed during spring (September) and the genera Cocconeis, Grammatophora and Navicula appearing regularly. To complement the sparse data from the long-term temporal study, a short-term experimental study on artificial substrata (Plexiglass) revealed rapid temporal variations of benthic diatom assemblages. The composition differed spatio-temporally during the experimental period, with fluctuating species occurrences and abundances between the two study sites. The experimental study also revealed the highest number of diatom species observed during this research (134 species belonging to 44 genera). While Cocconeis (13 species) and Nitzschia (9 species) were the dominant genera, 48% of the diatomcomposition was composed of rarely observed taxa that included Cocconeis testudo Giffen, Donkinia sp., Paralia sulcata (Ehrenberg) Cleve. Regarding environmental drivers, the findings indicated the importance of temperature and nutrients in driving diatom spatial abundance and composition along the coastline, as well as the island. However, the potential influence of the interplay between measured variables and unexplored coastal oceanographic processes (e.g., wave action) was noted. Temporally, from the annual study, the nature of the rocky substrate (rock type) rather than environmental conditions was postulated to have been the influential factor that resulted in the low diatom abundance data, however this requires further in-depth investigations on the influence of rock microtopography on microphytobenthos in this region. Contrastingly, the experimental study results indicated environmental variables having varying influences on the diatom diversity indices, however, study site and sampling occasion were revealed as the most important predictors of the observed variability. Further, site-specific biofilm processes, including biological interaction (e.g. grazing), were shown to alter biofilm succession, thus influencing the observed diatom assemblages. Overall, this research provided new and relevant knowledge on the variability of benthic (epilithic) diatom composition, biodiversity and distribution along the coastline, further contributing to our understanding of marine benthic diatoms ecology, their ecological role in the context of intertidal food web and their potential as bioindicators of change in the coastal ecosystems in Southern Africa. , Thesis (PhD) -- Faculty of Science, School of Environmental Sciences, 2023
- Full Text:
- Date Issued: 2023-12
- Authors: Cotiyane-Pondo, Phumlile
- Date: 2023-12
- Subjects: Marine ecology , Marine biodiversity , Coastal ecology
- Language: English
- Type: Doctorate Dissertation , text
- Identifier: http://hdl.handle.net/10948/62453 , vital:72754
- Description: Diatoms remain one of the most diverse and ecologically important microorganisms within microphytobenthos. The highly variable South African coastline, comprised of heterogeneous rocky intertidal habitats provides the ideal study area to investigate epilithic microphytobenthos and their associated influential drivers. In South Africa, in-depth taxonomic research on marine littoral diatoms exists, however, quantitative research and knowledge on their abundance, diversity, community composition and distribution remain limited. Thus, the main aim of this research was to explore the spatial and temporal variability of marine benthic (epilithic) diatoms, in relation to the variable physico-chemical conditions in the nearshore intertidal environments along the coastline of South Africa. To achieve this, field-based observational (natural substrata) and experimental (artificial substrata) studies were conducted on selected locations around the coastline, with a large focus on south coast localities. For the Spatial studies, large (i.e., encompassing all three biogeographical regions) and small-scale (i.e., coastal island in the warm temperate region) surveys of epilithic diatom assemblages from natural rocky substrata were conducted. Large-scale investigation results revealed highly variable diatom assemblages, diversity and distribution, with compositional differences observed between the coastal sections (around the coastline). A total of 85 diatom taxa from 31 genera were observed at 15 sites, and the number of taxa varied un-systematically along coastline. Genera with noticeable contribution included Nitzschia, Cocconeis and Achnanthes. On the coastal Bird Island (small-scale), similar variability was observed, but with a much higher diatom diversity and number of rarely observed species (e.g. Actinoptychus senarius (Ehrenberg) Ehrenberg, Cocconeis capensis (Cholnoky) Witkowski, Fragilariopsis kerguelensis (O’Meara) Hustedt, Striatella unipunctata (Lyngbye) Agardh. Seventy-two (72) species from 35 genera were recorded with a varied abundance and diversity around the island. The study also revealed a high contribution of typical benthic diatom species to the surf zone environment around the island. To study temporal variations, medium-term compositional differences on natural substrata were assessed monthly over an annual cycle at a single site. A paucity of diatom material was evident during this study and observations indicated a trend of presence and absence of diatom taxa from the study site. Nineteen (19) diatom genera were identified and those observed, albeit as one or two individual valves, included taxa from several genera including Biddulphia, Diploneis, Campyloneis, Trachyneis and Triceratium. Noteworthy was a seasonal increase in the number of diatom valves encountered, with the highest diatom abundance observed during spring (September) and the genera Cocconeis, Grammatophora and Navicula appearing regularly. To complement the sparse data from the long-term temporal study, a short-term experimental study on artificial substrata (Plexiglass) revealed rapid temporal variations of benthic diatom assemblages. The composition differed spatio-temporally during the experimental period, with fluctuating species occurrences and abundances between the two study sites. The experimental study also revealed the highest number of diatom species observed during this research (134 species belonging to 44 genera). While Cocconeis (13 species) and Nitzschia (9 species) were the dominant genera, 48% of the diatomcomposition was composed of rarely observed taxa that included Cocconeis testudo Giffen, Donkinia sp., Paralia sulcata (Ehrenberg) Cleve. Regarding environmental drivers, the findings indicated the importance of temperature and nutrients in driving diatom spatial abundance and composition along the coastline, as well as the island. However, the potential influence of the interplay between measured variables and unexplored coastal oceanographic processes (e.g., wave action) was noted. Temporally, from the annual study, the nature of the rocky substrate (rock type) rather than environmental conditions was postulated to have been the influential factor that resulted in the low diatom abundance data, however this requires further in-depth investigations on the influence of rock microtopography on microphytobenthos in this region. Contrastingly, the experimental study results indicated environmental variables having varying influences on the diatom diversity indices, however, study site and sampling occasion were revealed as the most important predictors of the observed variability. Further, site-specific biofilm processes, including biological interaction (e.g. grazing), were shown to alter biofilm succession, thus influencing the observed diatom assemblages. Overall, this research provided new and relevant knowledge on the variability of benthic (epilithic) diatom composition, biodiversity and distribution along the coastline, further contributing to our understanding of marine benthic diatoms ecology, their ecological role in the context of intertidal food web and their potential as bioindicators of change in the coastal ecosystems in Southern Africa. , Thesis (PhD) -- Faculty of Science, School of Environmental Sciences, 2023
- Full Text:
- Date Issued: 2023-12
Sustainable conservation practices in Tigray, Ethiopia
- Authors: Assefa, Mulat Zinabu
- Date: 2023-12
- Subjects: Nature conservation -- Economic aspects , Biodiversity conservation -- Economic aspects , Sustainable development -- Ethiopia
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/65532 , vital:74185
- Description: After the short-lived Derg regime's land reform in 1975, Ethiopia's smallholder farmers were granted equitable tenure and ownership rights for the first time in history. Furthermore, since 1991 there was a growing desire for better living conditions among smallholder farmers. As a result of the involvement of smallholder farmers, Sustainable Conservation Practices (SCP) was regarded as an effective symbol of government land and rural development policy in Ethiopia in the last two decades. SCP in Tigray, Ethiopia has been hailed as a model of conservation practices impacting the livelihoods of smallholder farmers and sustainable development. It has, however, been accompanied by both criticism and acclaim. Contrary to the success narratives of the SCP, Tigray's smallholder farmers continue to face livelihood challenges and climate threats. The primary aim of this study was to critically assess and explain the livelihood impact of SCPs and ongoing participation in soil and water conservation practices (SWCPs) among Tigrayan smallholder farmers. Previously, studies on the issue have focused on SWC techniques or local watershed management. There has been a lack of adequate research on the historical and political interactions between smallholder farmers and the state regarding land conservation in the past two decades. A mixed method approach was used to address this knowledge gap in four tabiyas through multiple sampling methods, using purposive sampling methods to select two reported models of conservation and random sampling methods to select two average tabiyas, in three different woredas. Mixed methods research was used to combine quantitative and qualitative data collection and analysis techniques. The study revealed that Ethiopia's land use laws and policies under previous regimes have led to current challenges in sustainable land conservation and poverty reduction. As a result of land tenure laws and rights imposed by previous regimes, the challenges for the sustainable land use rights and land conservation practices continue to impact the livelihood of smallholder farmers. To demonstrate the success of land reform and conservation efforts, the government has been promoting the continued use of SWC practices by smallholder farmers in the last two decades. As part of SWC practices, political mobilisation and incentives such as safety-net programmes and agricultural inputs are used to encourage participation. Despite admirable advances in land degradation management, there were no appreciable differences between the results from the model and the average tabiya categories in terms of livelihood improvements. The success of the model tabiyas has proven difficult to replicate and it is still too early to judge whether the success of model tabiyas will be sustainable if they do not continue to receive extensive support from government and external stakeholders. The integration of local knowledge is crucial for the success of SCP, and the cumulative effect of the ‗one size fits all‘ approach in Tigray contributed to the failure to see substantial changes in the rural households. Thus, this study recommends the transformation of the rural and agricultural sector requires comprehensive, reliable, indigenous, and scientific paths that are informed by the local and lived experience of the rural households, rather than telling the success stories of conservation over again. , Thesis (PhD) -- Faculty of Business and Economic Sciences, School of Economics, Development and Tourism, 2023
- Full Text:
- Date Issued: 2023-12
- Authors: Assefa, Mulat Zinabu
- Date: 2023-12
- Subjects: Nature conservation -- Economic aspects , Biodiversity conservation -- Economic aspects , Sustainable development -- Ethiopia
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/65532 , vital:74185
- Description: After the short-lived Derg regime's land reform in 1975, Ethiopia's smallholder farmers were granted equitable tenure and ownership rights for the first time in history. Furthermore, since 1991 there was a growing desire for better living conditions among smallholder farmers. As a result of the involvement of smallholder farmers, Sustainable Conservation Practices (SCP) was regarded as an effective symbol of government land and rural development policy in Ethiopia in the last two decades. SCP in Tigray, Ethiopia has been hailed as a model of conservation practices impacting the livelihoods of smallholder farmers and sustainable development. It has, however, been accompanied by both criticism and acclaim. Contrary to the success narratives of the SCP, Tigray's smallholder farmers continue to face livelihood challenges and climate threats. The primary aim of this study was to critically assess and explain the livelihood impact of SCPs and ongoing participation in soil and water conservation practices (SWCPs) among Tigrayan smallholder farmers. Previously, studies on the issue have focused on SWC techniques or local watershed management. There has been a lack of adequate research on the historical and political interactions between smallholder farmers and the state regarding land conservation in the past two decades. A mixed method approach was used to address this knowledge gap in four tabiyas through multiple sampling methods, using purposive sampling methods to select two reported models of conservation and random sampling methods to select two average tabiyas, in three different woredas. Mixed methods research was used to combine quantitative and qualitative data collection and analysis techniques. The study revealed that Ethiopia's land use laws and policies under previous regimes have led to current challenges in sustainable land conservation and poverty reduction. As a result of land tenure laws and rights imposed by previous regimes, the challenges for the sustainable land use rights and land conservation practices continue to impact the livelihood of smallholder farmers. To demonstrate the success of land reform and conservation efforts, the government has been promoting the continued use of SWC practices by smallholder farmers in the last two decades. As part of SWC practices, political mobilisation and incentives such as safety-net programmes and agricultural inputs are used to encourage participation. Despite admirable advances in land degradation management, there were no appreciable differences between the results from the model and the average tabiya categories in terms of livelihood improvements. The success of the model tabiyas has proven difficult to replicate and it is still too early to judge whether the success of model tabiyas will be sustainable if they do not continue to receive extensive support from government and external stakeholders. The integration of local knowledge is crucial for the success of SCP, and the cumulative effect of the ‗one size fits all‘ approach in Tigray contributed to the failure to see substantial changes in the rural households. Thus, this study recommends the transformation of the rural and agricultural sector requires comprehensive, reliable, indigenous, and scientific paths that are informed by the local and lived experience of the rural households, rather than telling the success stories of conservation over again. , Thesis (PhD) -- Faculty of Business and Economic Sciences, School of Economics, Development and Tourism, 2023
- Full Text:
- Date Issued: 2023-12
The effect of entrepreneurial competencies on the performance of small micro and medium enterprises in or Tambo District, Eastern Cape
- Authors: Senzeni, Phumlani
- Date: 2023-12
- Subjects: New business enterprises -- South Africa -- Eastern Cape , Small business -- South Africa -- Eastern Cape , Performance -- Management
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/28960 , vital:75577
- Description: The Small Micro and Medium Enterprises (SMMEs) remain the key competitor in the development of the economy growth of the country. The SMME sector is the key driver to the national economy of countries, as it creates job opportunities, reduce poverty, supports household income, and improve the people’s standard of living. However, the rate at which SMMEs fail to succeed results in non-performance and business closure, and this is alarming and require attention. The reasons for this failure can emanate from a number of reasons, such as lack of entrepreneurial competencies, managerial skills, lack of intellectual personnel, low entrepreneurial culture and obstacles that hinder access to resources and market. Therefore, in this study the researcher examined the effect of entrepreneurial competencies on the performance of SMMEs in OR Tambo District, Eastern Cape. The researcher adopted quantitative research approach. The research data was collected using Google Forms survey method. The emails containing the link to access the instrument were sent to a sample of 399 SMMEs in the OR Tambo District. The response rate of 74%, which is 294 was attained. Thus, the findings of the study discovered that entrepreneurial competencies have significant effect on the performance of SMMEs. The study further found that entrepreneurial competencies “opportunity recognition, creative-problem solving, resource leveraging, and business networking” had a low degree of association with business performance although they are statistically significant to business performance. The self-efficacy was found with a high degree of association with business performance and statistically significant with the achievement of positive beta and low p-value which indicated a strong association to performance. The study made conclusions that entrepreneurial competencies have positive effect on the performance of SMMEs. Therefore, it was concluded that performing and successful SMMEs in the regions means employment opportunities in the country because they require human resources to do operational services and render services. The government and policymakers are encouraged to work together to form and strengthen development programs to assist SMMEs to grow the production capacity, operations and become productive. The SMMEs owners/managers and practitioners on skills development are encouraged to relook and strengthen entrepreneurial competencies that contribute to productivity and performance. , Thesis (DBA) -- Faculty of Management and Commerce, 2023
- Full Text:
- Date Issued: 2023-12
- Authors: Senzeni, Phumlani
- Date: 2023-12
- Subjects: New business enterprises -- South Africa -- Eastern Cape , Small business -- South Africa -- Eastern Cape , Performance -- Management
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/28960 , vital:75577
- Description: The Small Micro and Medium Enterprises (SMMEs) remain the key competitor in the development of the economy growth of the country. The SMME sector is the key driver to the national economy of countries, as it creates job opportunities, reduce poverty, supports household income, and improve the people’s standard of living. However, the rate at which SMMEs fail to succeed results in non-performance and business closure, and this is alarming and require attention. The reasons for this failure can emanate from a number of reasons, such as lack of entrepreneurial competencies, managerial skills, lack of intellectual personnel, low entrepreneurial culture and obstacles that hinder access to resources and market. Therefore, in this study the researcher examined the effect of entrepreneurial competencies on the performance of SMMEs in OR Tambo District, Eastern Cape. The researcher adopted quantitative research approach. The research data was collected using Google Forms survey method. The emails containing the link to access the instrument were sent to a sample of 399 SMMEs in the OR Tambo District. The response rate of 74%, which is 294 was attained. Thus, the findings of the study discovered that entrepreneurial competencies have significant effect on the performance of SMMEs. The study further found that entrepreneurial competencies “opportunity recognition, creative-problem solving, resource leveraging, and business networking” had a low degree of association with business performance although they are statistically significant to business performance. The self-efficacy was found with a high degree of association with business performance and statistically significant with the achievement of positive beta and low p-value which indicated a strong association to performance. The study made conclusions that entrepreneurial competencies have positive effect on the performance of SMMEs. Therefore, it was concluded that performing and successful SMMEs in the regions means employment opportunities in the country because they require human resources to do operational services and render services. The government and policymakers are encouraged to work together to form and strengthen development programs to assist SMMEs to grow the production capacity, operations and become productive. The SMMEs owners/managers and practitioners on skills development are encouraged to relook and strengthen entrepreneurial competencies that contribute to productivity and performance. , Thesis (DBA) -- Faculty of Management and Commerce, 2023
- Full Text:
- Date Issued: 2023-12
The impact of political instability on exchange rates in South Africa: an econometric modelling
- Munzhelele, Tshilidzi Whitney
- Authors: Munzhelele, Tshilidzi Whitney
- Date: 2023-12
- Subjects: Econometric models , Economics -- Statistical methods , Finance -- Econometric models , Foreign exchange rates -- Econometric models
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/65861 , vital:74278
- Description: The exchange rate and political instability are crucial macroeconomic variables strongly related to every economy. In South Africa, exchange rate fluctuations are widely related to major political events. The study analyses the fluctuations in exchange rates by applying exchange rate data over the period 1989 to 2020. The current study, used the predictive quantitative design that combines correlational analysis with predictive modelling. The Unit root results show that political instability and exchange rate are stationary at first difference, and inflation, GDP, political instability, the rule of law, and corruption control and corruption freedom are stationary at level. The Vector Auto Regression model (VAR) was applied to examine the short-run relationship between political instability exchange rate, GDP, inflation, real interest rate, corruption and the rule of law. The results show a short-run relationship between political instability, exchange rate, GDP, inflation, real interest rate, corruption and rule of law. Johansen Cointegration testing was also performed to establish cointegration between variables. The results from the Johansen tests suggest that the model presents a cointegration between political instability, GDP, inflation, real interest rate, corruption and the rule of law and exchange rate, implying that these variables are related and can be combined linearly. The VECM was performed to establish a long-run relationship between variables since cointegration was established between variables. The Vector Error Correction (VEC) model complemented these findings resulting in the null hypothesis that states there is no long-run relationship between variables being rejected. The alternative hypothesis that there is a long-run relationship between variables was accepted. The Granger Causality test was performed to examine the causality between variables and to examine the drivers and causes of exchange rate fluctuations in the VAR model. The results revealed that political instability does not Granger cause exchange rate fluctuations in the short run and that there is a negative relationship between political instability and exchange rate fluctuations. The short-run results revealed that the exchange rate does not Granger cause political instability. However, the exchange rate Granger causes the country's political instability in the long run. This study’s literature review found that political instability harms exchange rates and the economy, and its impact can be felt globally. The results of the study show that there is a negative relationship between political instability and exchange rates. In the short run, the results show that political instability Granger causes inflation. The impulse response function (IRF) was conducted to determine the shock of political instability on the exchange rate. The findings indicate that the magnitude of the shock refers to one standard deviation. The results show that after two years, 92% of the shock in exchange rates is due to the shock on the exchange rate itself, and only 0.12% is due to political instability in the short run. This means that the shock on the exchange rate is associated with the exchange rate itself. The result is consistent with empirical findings in South Africa that fluctuations, in the long run, are largely caused by political instability from corruption. The exchange rate results and the political instability response were used to calibrate the long-run response to exchange rate fluctuation. Political instability was also used to assess the nexus between political instability and economic growth. The results determine a positive relationship between political instability and economic growth. The IRF was performed to track the impact of a variable on other variables (that is, the exchange rate on political instability, GDP, corruption, inflation, real interest rate, the rule of law, and corruption) in the system from several periods in the future. The Autoregressive Integrated Moving Average (ARIMA) model for forecasting was selected because it provides an accurate forecast and satisfies the criteria for an ideal model. The results show that in the future, not much variation can be expected in the long run, meaning that political instability is projected to stabilise from 2021 to 2040, and the exchange rate will increase. The results from the analysis of exchange rates and political instability confirm the existence of a negative relationship between political instability and exchange rates. The findings of the study point to a need for the South African government to immediately respond to an increase in exchange rates and to stabilise the undercurrents caused by macroeconomic shocks. The study will contribute to the theoretical understanding of fluctuations in exchange rates and the formulation of macroeconomic stabilisation. , Thesis (PhD) -- Faculty of Business and Economic Sciences, School of Economics, Development and Tourism , 2023
- Full Text:
- Date Issued: 2023-12
- Authors: Munzhelele, Tshilidzi Whitney
- Date: 2023-12
- Subjects: Econometric models , Economics -- Statistical methods , Finance -- Econometric models , Foreign exchange rates -- Econometric models
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/65861 , vital:74278
- Description: The exchange rate and political instability are crucial macroeconomic variables strongly related to every economy. In South Africa, exchange rate fluctuations are widely related to major political events. The study analyses the fluctuations in exchange rates by applying exchange rate data over the period 1989 to 2020. The current study, used the predictive quantitative design that combines correlational analysis with predictive modelling. The Unit root results show that political instability and exchange rate are stationary at first difference, and inflation, GDP, political instability, the rule of law, and corruption control and corruption freedom are stationary at level. The Vector Auto Regression model (VAR) was applied to examine the short-run relationship between political instability exchange rate, GDP, inflation, real interest rate, corruption and the rule of law. The results show a short-run relationship between political instability, exchange rate, GDP, inflation, real interest rate, corruption and rule of law. Johansen Cointegration testing was also performed to establish cointegration between variables. The results from the Johansen tests suggest that the model presents a cointegration between political instability, GDP, inflation, real interest rate, corruption and the rule of law and exchange rate, implying that these variables are related and can be combined linearly. The VECM was performed to establish a long-run relationship between variables since cointegration was established between variables. The Vector Error Correction (VEC) model complemented these findings resulting in the null hypothesis that states there is no long-run relationship between variables being rejected. The alternative hypothesis that there is a long-run relationship between variables was accepted. The Granger Causality test was performed to examine the causality between variables and to examine the drivers and causes of exchange rate fluctuations in the VAR model. The results revealed that political instability does not Granger cause exchange rate fluctuations in the short run and that there is a negative relationship between political instability and exchange rate fluctuations. The short-run results revealed that the exchange rate does not Granger cause political instability. However, the exchange rate Granger causes the country's political instability in the long run. This study’s literature review found that political instability harms exchange rates and the economy, and its impact can be felt globally. The results of the study show that there is a negative relationship between political instability and exchange rates. In the short run, the results show that political instability Granger causes inflation. The impulse response function (IRF) was conducted to determine the shock of political instability on the exchange rate. The findings indicate that the magnitude of the shock refers to one standard deviation. The results show that after two years, 92% of the shock in exchange rates is due to the shock on the exchange rate itself, and only 0.12% is due to political instability in the short run. This means that the shock on the exchange rate is associated with the exchange rate itself. The result is consistent with empirical findings in South Africa that fluctuations, in the long run, are largely caused by political instability from corruption. The exchange rate results and the political instability response were used to calibrate the long-run response to exchange rate fluctuation. Political instability was also used to assess the nexus between political instability and economic growth. The results determine a positive relationship between political instability and economic growth. The IRF was performed to track the impact of a variable on other variables (that is, the exchange rate on political instability, GDP, corruption, inflation, real interest rate, the rule of law, and corruption) in the system from several periods in the future. The Autoregressive Integrated Moving Average (ARIMA) model for forecasting was selected because it provides an accurate forecast and satisfies the criteria for an ideal model. The results show that in the future, not much variation can be expected in the long run, meaning that political instability is projected to stabilise from 2021 to 2040, and the exchange rate will increase. The results from the analysis of exchange rates and political instability confirm the existence of a negative relationship between political instability and exchange rates. The findings of the study point to a need for the South African government to immediately respond to an increase in exchange rates and to stabilise the undercurrents caused by macroeconomic shocks. The study will contribute to the theoretical understanding of fluctuations in exchange rates and the formulation of macroeconomic stabilisation. , Thesis (PhD) -- Faculty of Business and Economic Sciences, School of Economics, Development and Tourism , 2023
- Full Text:
- Date Issued: 2023-12
An examination of the use and value of support systems for people living with HIV/AIDS in Makhanda
- Authors: Gorham, Catherine Margaret
- Date: 2023-10-13
- Subjects: HIV-positive persons South Africa Makhanda , AIDS (Disease) Patients South Africa Makhanda , Social networks , Diseases Social aspects , Health services accessibility , Narrative
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/432411 , vital:72868 , DOI 10.21504/10962/432411
- Description: Through the experiences of five people, this study asks how support systems develop, are used and are valued for those faced with the everyday challenges of living with HIV. Additional evidence is found in accounts from those identified as essential sources of support. These are primarily friends, sometimes family. This perspective is rounded out by insights gathered from those working in local organisations and in the analysis of services offered by the state. The three women and two men at the centre of this study live in Makhanda in the Eastern Cape, South Africa. Makhanda (formerly Grahamstown) is characterised by extremes of poverty and wealth, reflected in low employment, expanding informal and low-income settlement areas but also in a high level of community activism and access to resources. Each of the five tested positive for HIV variously between 1998 and 2008. These years were pivotal in the development of the local and national epidemic. The rapid expansion of infection rates, contestation over forms of and access to treatment, followed by emphasis of a biomedical response, in equal measure bracket and cut across their experiences. To this point, research is less concerned with what individual experiences say about living through the HIV/AIDS epidemic. Preoccupations lie more generally with macro- or micro-level factors, with behaviour change, managing risk and so public health – not the processes linking individual circumstances and choices to opportunities and outcomes described by individual, community and structural, socio-economic contexts. Personal accounts and observations of a developing, community-based, local response to an unfolding epidemic are therefore considered against the analysis of available medical and nonmedical resources. This enables identification and investigation of social processes operating between proximal and distal conditions, determining possibilities for access to support. The focus of this study thus falls to the interrelations of structure, agency and action. It contributes to an empirical and theoretical understanding of what “support” is, what “coping” means and what unfolds where diagnosis with HIV disrupts and challenges existing ways of coping and forms of support. The accounts gathered for this study offer an “insider” perspective, focused on what follows from testing positive to identifying what resources hold significance. Connections between individual, community and society, through psycho-social, local and macro-level processes are explored. Along with the empirical study of individual accounts, the thesis offers a theoretical framework that uses a grounded-theory approach in conjunction with the tools of narrative analysis. These are critically adapted from a sociology of illness studies. Ideas of risk and response, of material and social capital, of the nature of HIV/AIDS as an experience that is inclusive of both chronic, everyday challenge and critical, life-threatening crisis disrupting a sense of time, biography and self, are brought together in the analysis. In this way the understanding of what support means, how it develops and is used (systematically or not), and of the links operating between structural and social conditions, individual agency and action, can be developed. What the thesis finds is that, beyond the medical system of hospitals and clinics, there is surprisingly little use of available resources. There is thus an absence of any systematic support for those faced with the physical, psychological, social and material impacts of HIV/AIDS. Given the nature of personal circumstances, embedded as they are within local conditions that reflect structural constraints of the broader economy and society, this should not be surprising. A system of support exists in only the most limited definition. Against this, what is novel in these findings is the role that psycho-social processes play in negotiating these conditions and how this works, determining what unfolds. A key finding is that it is more through chance than choice that people do find conventional forms of support. The reasons for this have to do not only with limitations to state and institutional capacity, but also with the impact on individuals of perceptions of themselves shaped by the impact of the epidemic and also the past. The result is that under the burden of HIV/AIDS, in the context of extreme inequalities and the absence of an adequate response from the state, already invisible individuals who do not “count” run the risk of becoming doubly invisible. It is through a process of personal adaptation in which shifts in identity and a sense of self are key that they must find their own way. This involves re-conceptualisations of identity, a sense of self and place in the world. The focus on five people and the community in which they live is a limit to the scope of study Yet it is this focus which allows for a new understanding of the social processes involved, and so the links operating between individuals and society. This is of significance beyond the study of HIV/AIDS alone, contributing to the broader sociological project of understanding what it means to “be human”. , Thesis (PhD) -- Faculty of Humanities, Sociology, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Gorham, Catherine Margaret
- Date: 2023-10-13
- Subjects: HIV-positive persons South Africa Makhanda , AIDS (Disease) Patients South Africa Makhanda , Social networks , Diseases Social aspects , Health services accessibility , Narrative
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/432411 , vital:72868 , DOI 10.21504/10962/432411
- Description: Through the experiences of five people, this study asks how support systems develop, are used and are valued for those faced with the everyday challenges of living with HIV. Additional evidence is found in accounts from those identified as essential sources of support. These are primarily friends, sometimes family. This perspective is rounded out by insights gathered from those working in local organisations and in the analysis of services offered by the state. The three women and two men at the centre of this study live in Makhanda in the Eastern Cape, South Africa. Makhanda (formerly Grahamstown) is characterised by extremes of poverty and wealth, reflected in low employment, expanding informal and low-income settlement areas but also in a high level of community activism and access to resources. Each of the five tested positive for HIV variously between 1998 and 2008. These years were pivotal in the development of the local and national epidemic. The rapid expansion of infection rates, contestation over forms of and access to treatment, followed by emphasis of a biomedical response, in equal measure bracket and cut across their experiences. To this point, research is less concerned with what individual experiences say about living through the HIV/AIDS epidemic. Preoccupations lie more generally with macro- or micro-level factors, with behaviour change, managing risk and so public health – not the processes linking individual circumstances and choices to opportunities and outcomes described by individual, community and structural, socio-economic contexts. Personal accounts and observations of a developing, community-based, local response to an unfolding epidemic are therefore considered against the analysis of available medical and nonmedical resources. This enables identification and investigation of social processes operating between proximal and distal conditions, determining possibilities for access to support. The focus of this study thus falls to the interrelations of structure, agency and action. It contributes to an empirical and theoretical understanding of what “support” is, what “coping” means and what unfolds where diagnosis with HIV disrupts and challenges existing ways of coping and forms of support. The accounts gathered for this study offer an “insider” perspective, focused on what follows from testing positive to identifying what resources hold significance. Connections between individual, community and society, through psycho-social, local and macro-level processes are explored. Along with the empirical study of individual accounts, the thesis offers a theoretical framework that uses a grounded-theory approach in conjunction with the tools of narrative analysis. These are critically adapted from a sociology of illness studies. Ideas of risk and response, of material and social capital, of the nature of HIV/AIDS as an experience that is inclusive of both chronic, everyday challenge and critical, life-threatening crisis disrupting a sense of time, biography and self, are brought together in the analysis. In this way the understanding of what support means, how it develops and is used (systematically or not), and of the links operating between structural and social conditions, individual agency and action, can be developed. What the thesis finds is that, beyond the medical system of hospitals and clinics, there is surprisingly little use of available resources. There is thus an absence of any systematic support for those faced with the physical, psychological, social and material impacts of HIV/AIDS. Given the nature of personal circumstances, embedded as they are within local conditions that reflect structural constraints of the broader economy and society, this should not be surprising. A system of support exists in only the most limited definition. Against this, what is novel in these findings is the role that psycho-social processes play in negotiating these conditions and how this works, determining what unfolds. A key finding is that it is more through chance than choice that people do find conventional forms of support. The reasons for this have to do not only with limitations to state and institutional capacity, but also with the impact on individuals of perceptions of themselves shaped by the impact of the epidemic and also the past. The result is that under the burden of HIV/AIDS, in the context of extreme inequalities and the absence of an adequate response from the state, already invisible individuals who do not “count” run the risk of becoming doubly invisible. It is through a process of personal adaptation in which shifts in identity and a sense of self are key that they must find their own way. This involves re-conceptualisations of identity, a sense of self and place in the world. The focus on five people and the community in which they live is a limit to the scope of study Yet it is this focus which allows for a new understanding of the social processes involved, and so the links operating between individuals and society. This is of significance beyond the study of HIV/AIDS alone, contributing to the broader sociological project of understanding what it means to “be human”. , Thesis (PhD) -- Faculty of Humanities, Sociology, 2023
- Full Text:
- Date Issued: 2023-10-13
Analysing equity and ethical dimensions of water governance challenges in the lower section of the upper Vaal River catchment, Gauteng, South Africa
- Authors: Tavengwa, Noleen Shamiso
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424199 , vital:72132
- Description: Poor water governance practices have been identified as one of the root causes of water problems confronting the South African water sector. This is evident in the lower section of the Upper Vaal River Catchment, where ineffective implementation of the regulatory measures has resulted in multiple incidents of illegal discharge of effluent from municipal wastewater treatment works, industrial and mining activities. Pollution and deterioration of water quality is a major challenge in the catchment; the Vaal River is severely polluted beyond acceptable standards and impacts negatively on other water users who have legitimate rights to the water resources. Pollution not only affects human activities and use, but also has negative impacts on ecological health and functionality. Poor water governance practices raise ethical implications for the rights to water for both social and ecological components. Although many water governance challenges in South Africa have implications that border on values and ethics, the relationship between these concepts has hardly been explored. In order to contribute towards filling this gap, this study explores water governance challenges and their ethical implications, and then analyse the equity dimensions of key water challenges among institutional actors in the lower section of the Upper Vaal WMA, Gauteng. The study uses a qualitative research approach which involves several methods of data collection: document analysis, workshops, focus group discussions, key informant interviews and participant observation. The data collected were analysed using thematic analysis, and then applied an ethical framework to distil ethical implications of the identified water governance challenges. There are five water governance challenges that were identified, which are i) failure in the implementation of water legislation and regulations, ii) ineffective leadership and management, iii) cooperative governance and poor accountability, iv) decentralisation and ineffective participation, and v) finance, infrastructure, and technical capacity. The deterioration of water quality and pollution due to ineffective implementation of the regulatory system has ethical implications towards protection of the ecological system and sustainable management of the water resources for the present and future generation. Ineffective implementation of the regulatory measure also raises the issue of distributive equity between different water users and between current and future users. These implications are critical particularly when viewed from the perspective of systemic-relational ethical approach which posit that in social-ecological systems, all components ought to be treated with equal regards, and their inherent worth respected in order to maintain the unity of the SES. The idea of equal regards to the inherent worth of the component implies due respect, in ways that do not undermine the integrity of the entire system. The challenges identified in the system suggest that i) the right of the ecological system to water is undermined due to anthropogenic activities, which may in the long term undermine the functionality of the entire SES; ii) the right of the margined to access to water of the right quality is also undermined, and pollution costs is externalised. These are matters of ethics that thus deserved attention in policy and management considerations. The study analysed equity dimensions (distributive and procedural), targeting the key institutional water users (i.e., mines, industries, agriculture, municipalities, and the wastewater treatment works) in the lower section of the Upper Vaal River Catchment as equity candidates due to their activities that significantly impact the environment and the water resources. The cost of pollution caused by mining activities, industrial activities and the wastewater treatment works is externalised to other users who are not responsible for the pollution. In this regard study identified key drivers that raise concerns linked to distributive equity, which are ) pollution and water quality deterioration, ii) the legacies of mining activities, and iii) poor infrastructure maintenance, vandalism, and theft. Identifying these key drivers of distributive equity concerns is critical in ensuring that the water governance processes are designed in a way that stakeholders and actors reliant on water resources within the catchment have equitable and fair access without the effects of externalised costs from other actors. The identified water governance challenges in the catchment all borders on ethics, thus an ethical framework is crucial in tackling water related problems. The principles of ethics can be used as guidelines to decision-making process for the management and governance of water resources in South Africa. Therefore, implementing and incorporating principles of the systemic-relational ethics into policy making and water resources management will yield sustainable, efficient, and equitable use and management of water resources. , Thesis (MSc) -- Faculty of Science, Institute for Water Research, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Tavengwa, Noleen Shamiso
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424199 , vital:72132
- Description: Poor water governance practices have been identified as one of the root causes of water problems confronting the South African water sector. This is evident in the lower section of the Upper Vaal River Catchment, where ineffective implementation of the regulatory measures has resulted in multiple incidents of illegal discharge of effluent from municipal wastewater treatment works, industrial and mining activities. Pollution and deterioration of water quality is a major challenge in the catchment; the Vaal River is severely polluted beyond acceptable standards and impacts negatively on other water users who have legitimate rights to the water resources. Pollution not only affects human activities and use, but also has negative impacts on ecological health and functionality. Poor water governance practices raise ethical implications for the rights to water for both social and ecological components. Although many water governance challenges in South Africa have implications that border on values and ethics, the relationship between these concepts has hardly been explored. In order to contribute towards filling this gap, this study explores water governance challenges and their ethical implications, and then analyse the equity dimensions of key water challenges among institutional actors in the lower section of the Upper Vaal WMA, Gauteng. The study uses a qualitative research approach which involves several methods of data collection: document analysis, workshops, focus group discussions, key informant interviews and participant observation. The data collected were analysed using thematic analysis, and then applied an ethical framework to distil ethical implications of the identified water governance challenges. There are five water governance challenges that were identified, which are i) failure in the implementation of water legislation and regulations, ii) ineffective leadership and management, iii) cooperative governance and poor accountability, iv) decentralisation and ineffective participation, and v) finance, infrastructure, and technical capacity. The deterioration of water quality and pollution due to ineffective implementation of the regulatory system has ethical implications towards protection of the ecological system and sustainable management of the water resources for the present and future generation. Ineffective implementation of the regulatory measure also raises the issue of distributive equity between different water users and between current and future users. These implications are critical particularly when viewed from the perspective of systemic-relational ethical approach which posit that in social-ecological systems, all components ought to be treated with equal regards, and their inherent worth respected in order to maintain the unity of the SES. The idea of equal regards to the inherent worth of the component implies due respect, in ways that do not undermine the integrity of the entire system. The challenges identified in the system suggest that i) the right of the ecological system to water is undermined due to anthropogenic activities, which may in the long term undermine the functionality of the entire SES; ii) the right of the margined to access to water of the right quality is also undermined, and pollution costs is externalised. These are matters of ethics that thus deserved attention in policy and management considerations. The study analysed equity dimensions (distributive and procedural), targeting the key institutional water users (i.e., mines, industries, agriculture, municipalities, and the wastewater treatment works) in the lower section of the Upper Vaal River Catchment as equity candidates due to their activities that significantly impact the environment and the water resources. The cost of pollution caused by mining activities, industrial activities and the wastewater treatment works is externalised to other users who are not responsible for the pollution. In this regard study identified key drivers that raise concerns linked to distributive equity, which are ) pollution and water quality deterioration, ii) the legacies of mining activities, and iii) poor infrastructure maintenance, vandalism, and theft. Identifying these key drivers of distributive equity concerns is critical in ensuring that the water governance processes are designed in a way that stakeholders and actors reliant on water resources within the catchment have equitable and fair access without the effects of externalised costs from other actors. The identified water governance challenges in the catchment all borders on ethics, thus an ethical framework is crucial in tackling water related problems. The principles of ethics can be used as guidelines to decision-making process for the management and governance of water resources in South Africa. Therefore, implementing and incorporating principles of the systemic-relational ethics into policy making and water resources management will yield sustainable, efficient, and equitable use and management of water resources. , Thesis (MSc) -- Faculty of Science, Institute for Water Research, 2023
- Full Text:
- Date Issued: 2023-10-13
Beyond mastery: jazz, gender and power in postapartheid South Africa
- Authors: Williams, Ulagh
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/432505 , vital:72876 , DOI 10.21504/10962/432512
- Description: This dissertation studies the musical lives of seven South African women who have built highprofile national and international careers as jazz musicians. Empirically it records self-reported experiences and actions that they have identified as relevant to their success within a notoriously patriarchal field. Drawing on feminist research methods and Interpretative Phenomenological Analysis the dissertation strives to develop an empathic yet critical epistemological framework attuned to the complexities of their lived experiences as women and as jazz musicians. Theoretically it investigates the power relations at play in the myriad ways they negotiate or have been impelled to negotiate gender and patriarchy as musicians. Chapter one draws attention to the ubiquity of patriarchy in South African and international jazz culture, and highlights the research participants’ numerous successes to date as performers, educators, composers, and bandleaders. Chapter two positions this study in relation to cognate work in South African jazz studies, international feminist jazz studies and feminist phenomenology. Chapters three to five successively consider the participants’ early enculturation as musical and gendered subjects, their agentic responses to structures of patriarchy and/or race as emerging and established professionals, and the ways these experiences have found expression in some of their musical utterances as performers and composers. Fusing art and activism, the participants challenge and transcend masculinist discourses of mastery that still dominate South African jazz as a field of production and aesthetic practice. , Thesis (PhD) -- Faculty of Humanities, Music and Musicology, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Williams, Ulagh
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/432505 , vital:72876 , DOI 10.21504/10962/432512
- Description: This dissertation studies the musical lives of seven South African women who have built highprofile national and international careers as jazz musicians. Empirically it records self-reported experiences and actions that they have identified as relevant to their success within a notoriously patriarchal field. Drawing on feminist research methods and Interpretative Phenomenological Analysis the dissertation strives to develop an empathic yet critical epistemological framework attuned to the complexities of their lived experiences as women and as jazz musicians. Theoretically it investigates the power relations at play in the myriad ways they negotiate or have been impelled to negotiate gender and patriarchy as musicians. Chapter one draws attention to the ubiquity of patriarchy in South African and international jazz culture, and highlights the research participants’ numerous successes to date as performers, educators, composers, and bandleaders. Chapter two positions this study in relation to cognate work in South African jazz studies, international feminist jazz studies and feminist phenomenology. Chapters three to five successively consider the participants’ early enculturation as musical and gendered subjects, their agentic responses to structures of patriarchy and/or race as emerging and established professionals, and the ways these experiences have found expression in some of their musical utterances as performers and composers. Fusing art and activism, the participants challenge and transcend masculinist discourses of mastery that still dominate South African jazz as a field of production and aesthetic practice. , Thesis (PhD) -- Faculty of Humanities, Music and Musicology, 2023
- Full Text:
- Date Issued: 2023-10-13
Click consonants in contact: a comparative sociohistorical analysis with special reference to Nama-Afrikaans contact
- Authors: Christie, Camilla Rose
- Date: 2023-10-13
- Subjects: Click consonant , Language contact , Sociohistorical linguistics , Sociolinguistics , Nama language , Khoekhoe , African languages , Linguistic borrowing
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/432370 , vital:72865 , DOI 10.21504/10962/432370
- Description: Despite their ubiquity across southern Africa, click consonants are among the world’s most poorly understood speech sounds. Details of their phonological behaviour during language contact remain unclear, in large part because of the under-documentation of contact events of marginalised languages in rural contexts. Working within a sociohistorical linguistic framework with reference to material socioeconomic theories of language contact, this thesis compares and contrasts the diachronic phonological outcomes of various click loan events. The primary event under investigation is the donation of loanwords from an endangered click language, Nama, via substrate interference with the lexicon of a socially dominant clickless language, Afrikaans, in the Namaqualand region of the Northern Cape. The phonological adaptations employed to integrate donated lexical material into a host grammar ought ordinarily to be fairly regular, but the cross-linguistic rarity of click consonants complicates this process. The twenty click consonants expected of Nama undergo phonemic neutralisation when realised in Namaqualand Afrikaans, such that contrast embedded in click ‘type’ and click ‘accompaniment’ is collapsed. Speakers of Namaqualand Afrikaans employ any click type when uttering any click word, and may even use different click types in different tokens of the same lexical item. This unpredictability neutralises contrast. Nonetheless, there is some evidence of a diachronic trend from the unpredictable use of multiple click types and accompaniments toward the stable use of only the linguopulmonic dental click. When these novel data are set against the phonological outcomes of other contact events between a click language and a clickless languages across southern Africa, the normal outcome of click loan under is shown to be the collapse of ‘type’ contrasts. An important outlier is the large ‘type’-contrasting click inventory still shared by isiXhosa and isiZulu long after the extinction of donor click languages in the Khoekhoe branch, suggesting that this contact event must historically have entailed sustained community-wide bilingualism. These comparative observations are used to develop a cross-linguistic typology of click loan events that aims to improve our understanding of the precolonial linguistic landscape of southern Africa. The improved documentation of click consonants in rural language varieties is urgently recommended. , Thesis (PhD) -- Faculty of Humanities, Linguistics and Applied Language Studies, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Christie, Camilla Rose
- Date: 2023-10-13
- Subjects: Click consonant , Language contact , Sociohistorical linguistics , Sociolinguistics , Nama language , Khoekhoe , African languages , Linguistic borrowing
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/432370 , vital:72865 , DOI 10.21504/10962/432370
- Description: Despite their ubiquity across southern Africa, click consonants are among the world’s most poorly understood speech sounds. Details of their phonological behaviour during language contact remain unclear, in large part because of the under-documentation of contact events of marginalised languages in rural contexts. Working within a sociohistorical linguistic framework with reference to material socioeconomic theories of language contact, this thesis compares and contrasts the diachronic phonological outcomes of various click loan events. The primary event under investigation is the donation of loanwords from an endangered click language, Nama, via substrate interference with the lexicon of a socially dominant clickless language, Afrikaans, in the Namaqualand region of the Northern Cape. The phonological adaptations employed to integrate donated lexical material into a host grammar ought ordinarily to be fairly regular, but the cross-linguistic rarity of click consonants complicates this process. The twenty click consonants expected of Nama undergo phonemic neutralisation when realised in Namaqualand Afrikaans, such that contrast embedded in click ‘type’ and click ‘accompaniment’ is collapsed. Speakers of Namaqualand Afrikaans employ any click type when uttering any click word, and may even use different click types in different tokens of the same lexical item. This unpredictability neutralises contrast. Nonetheless, there is some evidence of a diachronic trend from the unpredictable use of multiple click types and accompaniments toward the stable use of only the linguopulmonic dental click. When these novel data are set against the phonological outcomes of other contact events between a click language and a clickless languages across southern Africa, the normal outcome of click loan under is shown to be the collapse of ‘type’ contrasts. An important outlier is the large ‘type’-contrasting click inventory still shared by isiXhosa and isiZulu long after the extinction of donor click languages in the Khoekhoe branch, suggesting that this contact event must historically have entailed sustained community-wide bilingualism. These comparative observations are used to develop a cross-linguistic typology of click loan events that aims to improve our understanding of the precolonial linguistic landscape of southern Africa. The improved documentation of click consonants in rural language varieties is urgently recommended. , Thesis (PhD) -- Faculty of Humanities, Linguistics and Applied Language Studies, 2023
- Full Text:
- Date Issued: 2023-10-13
Comparison of the metabolic physiology of exploited and unexploited populations of red roman (Chrysoblephus laticeps) along the south coast of South Africa
- Authors: Nabani, Xolani Prince
- Date: 2023-10-13
- Subjects: Chrysoblephus laticeps , Marine fishes Climatic factors South Africa , Marine fishes Physiology South Africa , Marine fishes Metabolism , Respirometry , Marine protected area , Evolutionary impact of fishing
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424358 , vital:72146
- Description: Anthropogenic-induced climate change and exploitation pose threat to many marine fishes on which a vast majority of people around the world depend. Rapid changes in sea surface temperature have a direct impact on the physiology of ectothermic organisms such as fish, potentially resulting in changes to population distribution, abundance, and demographics. In the face of climate change, the impacts of increasing temperature variability on fish populations may be exacerbated by exploitation. Understanding how the resilience of exploited populations is affected by climate change is critical to predict how fishes will respond in the future. This study aimed to augment our knowledge on the impact of exploitation and thermal variability on fishes by comparing the thermal physiology of an exploited and unexploited population of the resident, reef-dwelling, Chrysoblephus laticeps. Twenty live fish were collected from the exploited, Cape St Francis and 18 fish from the unexploited, Goukamma Marine Protected Area and transported to the laboratory. The metabolic performance, in terms of standard metabolic rate (SMR), maximum metabolic rate (MMR) and aerobic scope (AS) of individual C. laticeps were estimated repeatedly at 10 ℃, 16 °C and 21 °C. Linear mixed effects models were used to examine the relationship between temperature, population, and metabolic rate and a ‘cvequality’ test analysis was used to compare the variance structure of the metabolic rate regression model for each population. Overall, the findings of this study show that Chrysoblephus laticeps from the unexploited population maintains a significantly higher aerobic scope (AS) across all temperature treatments (10, 16 and 21 ℃) when compared with those from the exploited population. In addition, the maximum metabolic rate (MMR) of individuals from the unexploited population was significantly higher than that of individuals from the exploited population, but there was no evidence to suggest that variability was significantly different between the populations. On the other hand, the individuals from an exploited population had a significantly higher standard metabolic rate (SMR) at high temperatures of 21 ℃, while the unexploited population had a low SMR at these high temperatures, but a high SMR at 10 ℃. Despite these differences there was no significant variation in the SMR between the two populations. The findings of this study confirm previous work on different exploited and unexploited populations of C. laticeps and together these findings suggest that hook and line exploitation lead to reduced physiological phenotypic diversity and reduced physiological performance in exploited fish populations. These findings emphasise the importance of incorporating the iii physiological information to develop viable fisheries management tools in the context of climate change. This study also highlights the effectiveness of MPAs in conserving highperformance physiological phenotypes to maintain phenotypic diversity in fish populations. Future research should aim to evaluate the efficacy of existing MPAs in preserving the physiological diversity of important hook and line fisheries species, while fisheries managers should consider augmenting their approaches through the incorporation of well-designed MPA’s to promote physiological diversity. This will be critical to advance the development of sustainable management practices, not only in a South African context but globally, where oceanic and coastal environmental conditions are expected to rapidly change in the future. , Thesis (MSc) -- Faculty of Science, Ichthyology and Fisheries Science, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Nabani, Xolani Prince
- Date: 2023-10-13
- Subjects: Chrysoblephus laticeps , Marine fishes Climatic factors South Africa , Marine fishes Physiology South Africa , Marine fishes Metabolism , Respirometry , Marine protected area , Evolutionary impact of fishing
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424358 , vital:72146
- Description: Anthropogenic-induced climate change and exploitation pose threat to many marine fishes on which a vast majority of people around the world depend. Rapid changes in sea surface temperature have a direct impact on the physiology of ectothermic organisms such as fish, potentially resulting in changes to population distribution, abundance, and demographics. In the face of climate change, the impacts of increasing temperature variability on fish populations may be exacerbated by exploitation. Understanding how the resilience of exploited populations is affected by climate change is critical to predict how fishes will respond in the future. This study aimed to augment our knowledge on the impact of exploitation and thermal variability on fishes by comparing the thermal physiology of an exploited and unexploited population of the resident, reef-dwelling, Chrysoblephus laticeps. Twenty live fish were collected from the exploited, Cape St Francis and 18 fish from the unexploited, Goukamma Marine Protected Area and transported to the laboratory. The metabolic performance, in terms of standard metabolic rate (SMR), maximum metabolic rate (MMR) and aerobic scope (AS) of individual C. laticeps were estimated repeatedly at 10 ℃, 16 °C and 21 °C. Linear mixed effects models were used to examine the relationship between temperature, population, and metabolic rate and a ‘cvequality’ test analysis was used to compare the variance structure of the metabolic rate regression model for each population. Overall, the findings of this study show that Chrysoblephus laticeps from the unexploited population maintains a significantly higher aerobic scope (AS) across all temperature treatments (10, 16 and 21 ℃) when compared with those from the exploited population. In addition, the maximum metabolic rate (MMR) of individuals from the unexploited population was significantly higher than that of individuals from the exploited population, but there was no evidence to suggest that variability was significantly different between the populations. On the other hand, the individuals from an exploited population had a significantly higher standard metabolic rate (SMR) at high temperatures of 21 ℃, while the unexploited population had a low SMR at these high temperatures, but a high SMR at 10 ℃. Despite these differences there was no significant variation in the SMR between the two populations. The findings of this study confirm previous work on different exploited and unexploited populations of C. laticeps and together these findings suggest that hook and line exploitation lead to reduced physiological phenotypic diversity and reduced physiological performance in exploited fish populations. These findings emphasise the importance of incorporating the iii physiological information to develop viable fisheries management tools in the context of climate change. This study also highlights the effectiveness of MPAs in conserving highperformance physiological phenotypes to maintain phenotypic diversity in fish populations. Future research should aim to evaluate the efficacy of existing MPAs in preserving the physiological diversity of important hook and line fisheries species, while fisheries managers should consider augmenting their approaches through the incorporation of well-designed MPA’s to promote physiological diversity. This will be critical to advance the development of sustainable management practices, not only in a South African context but globally, where oceanic and coastal environmental conditions are expected to rapidly change in the future. , Thesis (MSc) -- Faculty of Science, Ichthyology and Fisheries Science, 2023
- Full Text:
- Date Issued: 2023-10-13
Computational studies in human African trypanosomiasis
- Authors: Muronzi, Tendai
- Date: 2023-10-13
- Subjects: African trypanosomiasis , Apolipoprotein L1 , Docking , Protein-protein interactions , Homology modeling , Tetrahydrofolate dehydrogenase , Pteridine reductase
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/431883 , vital:72812 , DOI 10.21504/10962/431885
- Description: Human African trypanosomiasis (HAT) is a neglected tropical disease (NTD) caused by two subspecies of the parasite, namely Trypanosoma brucei (Tb) gambiense (g-HAT) and rhodesiense (r-HAT). HAT is endemic in sub-Saharan countries, where the parasite transmission vectors, tsetse flies, breed. An estimated 70 million people remain at risk of contracting the disease, where the infection is classified as acute or chronic for g-HAT and r-HAT, respectively, with both forms ending in fatal meningoencephalitis when left untreated. Both g-HAT and r-HAT are responsible for widespread fatal epidemics throughout sub-Saharan African history, resulting from the complex molecular interplay between trypanosomes and humans through unique, innate immunity evasion mechanisms. Of interest, the Tbr subspecies expresses a serum resistance-associated protein (SRA), which binds to human serum lytic factor, apolipoprotein L1 (ApoL1), nullifying any trypanocidal activity. In response, ApoL1 (G1 and G2) variants found in humans of sub-Saharan African lineage have been cited for conferring resistance to the r-HAT infection in an interaction that is not fully elucidated In the event of successful infection, current HAT chemotherapeutics are plagued with complexity of administration, poor efficacy, toxicity, and potential drug resistance, highlighting a need for improved approaches. The parasite folate pathway provides a strategic target for alternative anti-trypanosomal drug development as trypanosomatids are folate auxotrophs, requiring host folate for growth and survival. Validated drug targets pteridine reductase (TbPTR1) and dihydrofolate reductase (TbDHFR) are essential for salvaging cofactors folate and folate biopterin crucial to parasite survival, making them viable targets for anti-folate investigation. The overall aims of this thesis were to a) provide insights into the molecular and dynamic basis of the SRA and ApoL1 interplay in HAT infection and b) identify safer and more efficient anti-folate anti-trypanosomal drug alternatives through in silico approaches. To achieve our first aim, in silico structure prediction was applied to generate 3D models of ApoL1 C-terminal variants G0, G1, G1G/M, G2 and G1G2, and four SRA variants retrieved from the NCBI database. The SRA and ApoL1 structures were inspected dynamically to identify the effect of the variants through molecular dynamics (MD) simulations. Dynamic residue network (DRN) analysis of MD trajectories was fundamental in identifying residues playing a vital role in the intramolecular communication of both proteins in the presence of mutations. Protein-protein docking was then applied to calculate plausible SRA-ApoL1 C-terminal wild-type complex structures to further elucidate the nature of SRA-mediated infection. Through MD simulations, twelve SRA-ApoL1 dimeric structures were narrowed down from five to two energetically sound complexes. The two feasible SRA-ApoL1 complexes (1 and 2) exhibited favourable communication observed through DRN analysis, including the retaining key communication residues identified in prior monomer DRN calculations. ApoL1 C-terminal variants were additionally incorporated into SRA-ApoL1 complexes 1 and 2 for further complex dynamics analysis This investigation into the nature of SRA-ApoL1 binding resulted in five primary outcomes: 1) highlighting the intramolecular effects ApoL1 variants have on the stability of the protein, 2) the identification of crucial SRA and ApoL1 communication residues in both monomeric or dimeric form, 3) the isolation of feasible SRA-ApoL1 complexes determined through global and local structural analyses 4) identification of residues crucial to the complex formation and maintenance of SRA-ApoL1, overlapping with those identified in (1), and 5) the minimal dissociative role of the G1 mutations in the complex, but compounding effect of the G2 deletion mutation. Computational modelling and drug repurposing were employed to achieve the thesis's second aim as they drastically cut down the costs involved in drug discovery and provide a more time-efficient screening method through numerous drug candidates. Using high throughput virtual screening, a subset of 2089 approved DrugBank compounds were screened against TbPTR1. The outputs were filtered to 24 viable compounds in 54 binding poses using binding energy and molecular interactions. Through subsequent MD simulations of 200ns, thirteen potential hit compounds were identified. The resultant hit compounds were subjected to further blind docking against TbDHFR and molecular dynamics to identify compounds with the potential for dual inhibition. The filtered subset was also tested in in vitro single concentration and dose-response bioassays to assess inhibitory properties against Trypanosoma brucei, complementing in silico findings. Post-molecular dynamics, four compounds exhibited high stabilities and molecular interactions with both TbPTR1 and TbDHFR, with two presenting favourable results in the in vitro assays. Three compounds additionally shared common structural moieties. In all, the in silico repurposing highlighted drugs characterised by favourable interactions and stabilities in TbPTR1, thus providing (1) a framework for further studies investigating anti-folate HAT compounds and (2) modulatory scaffolds based on identified moieties that can be used for the design of safe anti-folate trypanosomal drugs. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Muronzi, Tendai
- Date: 2023-10-13
- Subjects: African trypanosomiasis , Apolipoprotein L1 , Docking , Protein-protein interactions , Homology modeling , Tetrahydrofolate dehydrogenase , Pteridine reductase
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/431883 , vital:72812 , DOI 10.21504/10962/431885
- Description: Human African trypanosomiasis (HAT) is a neglected tropical disease (NTD) caused by two subspecies of the parasite, namely Trypanosoma brucei (Tb) gambiense (g-HAT) and rhodesiense (r-HAT). HAT is endemic in sub-Saharan countries, where the parasite transmission vectors, tsetse flies, breed. An estimated 70 million people remain at risk of contracting the disease, where the infection is classified as acute or chronic for g-HAT and r-HAT, respectively, with both forms ending in fatal meningoencephalitis when left untreated. Both g-HAT and r-HAT are responsible for widespread fatal epidemics throughout sub-Saharan African history, resulting from the complex molecular interplay between trypanosomes and humans through unique, innate immunity evasion mechanisms. Of interest, the Tbr subspecies expresses a serum resistance-associated protein (SRA), which binds to human serum lytic factor, apolipoprotein L1 (ApoL1), nullifying any trypanocidal activity. In response, ApoL1 (G1 and G2) variants found in humans of sub-Saharan African lineage have been cited for conferring resistance to the r-HAT infection in an interaction that is not fully elucidated In the event of successful infection, current HAT chemotherapeutics are plagued with complexity of administration, poor efficacy, toxicity, and potential drug resistance, highlighting a need for improved approaches. The parasite folate pathway provides a strategic target for alternative anti-trypanosomal drug development as trypanosomatids are folate auxotrophs, requiring host folate for growth and survival. Validated drug targets pteridine reductase (TbPTR1) and dihydrofolate reductase (TbDHFR) are essential for salvaging cofactors folate and folate biopterin crucial to parasite survival, making them viable targets for anti-folate investigation. The overall aims of this thesis were to a) provide insights into the molecular and dynamic basis of the SRA and ApoL1 interplay in HAT infection and b) identify safer and more efficient anti-folate anti-trypanosomal drug alternatives through in silico approaches. To achieve our first aim, in silico structure prediction was applied to generate 3D models of ApoL1 C-terminal variants G0, G1, G1G/M, G2 and G1G2, and four SRA variants retrieved from the NCBI database. The SRA and ApoL1 structures were inspected dynamically to identify the effect of the variants through molecular dynamics (MD) simulations. Dynamic residue network (DRN) analysis of MD trajectories was fundamental in identifying residues playing a vital role in the intramolecular communication of both proteins in the presence of mutations. Protein-protein docking was then applied to calculate plausible SRA-ApoL1 C-terminal wild-type complex structures to further elucidate the nature of SRA-mediated infection. Through MD simulations, twelve SRA-ApoL1 dimeric structures were narrowed down from five to two energetically sound complexes. The two feasible SRA-ApoL1 complexes (1 and 2) exhibited favourable communication observed through DRN analysis, including the retaining key communication residues identified in prior monomer DRN calculations. ApoL1 C-terminal variants were additionally incorporated into SRA-ApoL1 complexes 1 and 2 for further complex dynamics analysis This investigation into the nature of SRA-ApoL1 binding resulted in five primary outcomes: 1) highlighting the intramolecular effects ApoL1 variants have on the stability of the protein, 2) the identification of crucial SRA and ApoL1 communication residues in both monomeric or dimeric form, 3) the isolation of feasible SRA-ApoL1 complexes determined through global and local structural analyses 4) identification of residues crucial to the complex formation and maintenance of SRA-ApoL1, overlapping with those identified in (1), and 5) the minimal dissociative role of the G1 mutations in the complex, but compounding effect of the G2 deletion mutation. Computational modelling and drug repurposing were employed to achieve the thesis's second aim as they drastically cut down the costs involved in drug discovery and provide a more time-efficient screening method through numerous drug candidates. Using high throughput virtual screening, a subset of 2089 approved DrugBank compounds were screened against TbPTR1. The outputs were filtered to 24 viable compounds in 54 binding poses using binding energy and molecular interactions. Through subsequent MD simulations of 200ns, thirteen potential hit compounds were identified. The resultant hit compounds were subjected to further blind docking against TbDHFR and molecular dynamics to identify compounds with the potential for dual inhibition. The filtered subset was also tested in in vitro single concentration and dose-response bioassays to assess inhibitory properties against Trypanosoma brucei, complementing in silico findings. Post-molecular dynamics, four compounds exhibited high stabilities and molecular interactions with both TbPTR1 and TbDHFR, with two presenting favourable results in the in vitro assays. Three compounds additionally shared common structural moieties. In all, the in silico repurposing highlighted drugs characterised by favourable interactions and stabilities in TbPTR1, thus providing (1) a framework for further studies investigating anti-folate HAT compounds and (2) modulatory scaffolds based on identified moieties that can be used for the design of safe anti-folate trypanosomal drugs. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2023
- Full Text:
- Date Issued: 2023-10-13
Devastation and restoration: the use of Namibian dense salt blocks and the Cape Cross Salt Pans as visual metaphors
- Authors: Greyling, Wil-Merie
- Date: 2023-10-13
- Subjects: Sculpture , Destruction , Restoration and conservation , Salt pans in art , Grief in art , Loss (Psychology) in art , Visual metaphor , Salt mines and mining Namibia
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/437203 , vital:73352
- Description: This mini-thesis explores personal experiences during seasons of loss and grief using physical landscapes, specifically Namibian dense salt mining activities at the Cape Cross Salt Pans, as metaphors for devastation and restoration. Furthermore, the thesis investigates the connection between spiritual and physical landscapes through song and dreams to interpret personal experiences of loss and grief. The thesis explores how believers may find physical places of value outside the constraints of formal religious activities and how these experiences could evoke spiritual landscapes. The qualitative auto-ethnographical approach followed in this study proved an appropriate research methodology, explicitly involving observation and documentation of the physical landscape and reflection on personal experiences, such as dreams. In coming to terms with personal experiences of grief and loss, the individual results of the process were generated using methods such as retrospective reflection and observation. In my findings, I unpack how I found personal meaning from my creative and academic explorations. The metaphoric characteristics of dense salt blocks figuratively express ‘metamorphosis’, ‘weeping’, and ‘growth’. My findings include that one can represent healing and restorative elements with artistic value. The Namibian salt mining industry is typically removed from artistic activities and expression, but I succeeded in forging an atypical relationship with the industry players in an area of the salt block mining industry. In my practice, I explored the character of mined resources, in this case, dense salt blocks, by changing their inherent properties from low-value commercial minerals into unique art objects. In the process, I examined the metaphoric associations that organically mined material, in this case, salt blocks, may hold. Therefore, I link personal creative storytelling to a site with spiritual and sacred values and thus become a place to come to terms with loss and grief. , Thesis (MA) -- Faculty of Humanities, Fine Art, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Greyling, Wil-Merie
- Date: 2023-10-13
- Subjects: Sculpture , Destruction , Restoration and conservation , Salt pans in art , Grief in art , Loss (Psychology) in art , Visual metaphor , Salt mines and mining Namibia
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/437203 , vital:73352
- Description: This mini-thesis explores personal experiences during seasons of loss and grief using physical landscapes, specifically Namibian dense salt mining activities at the Cape Cross Salt Pans, as metaphors for devastation and restoration. Furthermore, the thesis investigates the connection between spiritual and physical landscapes through song and dreams to interpret personal experiences of loss and grief. The thesis explores how believers may find physical places of value outside the constraints of formal religious activities and how these experiences could evoke spiritual landscapes. The qualitative auto-ethnographical approach followed in this study proved an appropriate research methodology, explicitly involving observation and documentation of the physical landscape and reflection on personal experiences, such as dreams. In coming to terms with personal experiences of grief and loss, the individual results of the process were generated using methods such as retrospective reflection and observation. In my findings, I unpack how I found personal meaning from my creative and academic explorations. The metaphoric characteristics of dense salt blocks figuratively express ‘metamorphosis’, ‘weeping’, and ‘growth’. My findings include that one can represent healing and restorative elements with artistic value. The Namibian salt mining industry is typically removed from artistic activities and expression, but I succeeded in forging an atypical relationship with the industry players in an area of the salt block mining industry. In my practice, I explored the character of mined resources, in this case, dense salt blocks, by changing their inherent properties from low-value commercial minerals into unique art objects. In the process, I examined the metaphoric associations that organically mined material, in this case, salt blocks, may hold. Therefore, I link personal creative storytelling to a site with spiritual and sacred values and thus become a place to come to terms with loss and grief. , Thesis (MA) -- Faculty of Humanities, Fine Art, 2023
- Full Text:
- Date Issued: 2023-10-13
Distribution and habitat preferences of marine megafauna in Nosy Be, Madagascar
- Authors: Lubbé, Alicea
- Date: 2023-10-13
- Subjects: Marine animals Habitat Madagascar Nosy Be , Marine animals Geographical distribution Madagascar Nosy Be , Species distribution modelling , Maximum entropy method , Citizen science , Habitat preference
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424710 , vital:72177
- Description: Marine megafauna have important ecological roles including the top-down regulation of lower trophic levels and the transport of nutrients. They are also charismatic species of socioeconomic importance, due to their public appeal and focus for ecotourism. However, these taxa face numerous anthropogenic threats including bycatch, habitat-loss, noise disturbance, prey reductions, pollution, and vessel traffic. Northwest Madagascar has been identified as an important marine mammal area and whale shark aggregation site, yet limited information on megafauna within Madagascar exists. In this thesis, I investigated the community structure, distribution trends, related environmental factors (Chapter 2) and predicted habitat suitability (Chapter 3) using a species distribution modelling approach for marine megafauna around Nosy Be, North-west Madagascar. Data collection consisted of opportunistic boatbased surveys conducted while looking for whale sharks, mobulid rays and cetaceans. These activities were performed by dedicated ‘swim with whale shark’ tourism operators, Les Baleines Rand'eau and Safari Baleine during tourism activities directed by the Madagascar Whale Shark Project over four years (2016-2019). A total of 1792 sightings were reported with 13 identified species, including elasmobranchs: whale shark, Rhincodon typus; spinetail mobula ray, Mobula japonica; giant oceanic manta ray, Manta birostris; shortfin devil ray, Mobula kuhlii; balaenids: humpback whale, Megaptera novaeangliae; Omura's whale, Balaenoptera omurai, delphinids: Indo-Pacific bottlenose dolphin, Tursiops aduncus; spinner dolphin, Stenella longirostris; pantropical spotted dolphin, Stenella attenuata; Indian ocean humpback dolphin, Sousa plumbea; false killer whale, Pseudorca crassidens; melonheaded whale, Peponocephala electra and one cheloniid species: leatherback sea turtle, Dermochelys coriacea. Sightings were spatially analysed at a community level according to feeding guilds (i.e., filter feeders vs. predators), and distribution of the megafauna groups v were compared to selected remotely sensed physico-chemical data (sea surface temperature and chlorophyll-a concentration) and bathymetry charts (depth and slope) using generalized linear models (Chapter 2). All four variables had a significant effect on filter feeder distribution. Spatial distribution of filter feeder sightings peaked at an area of steep underwater topography (18-50m; x slope=0.5%) located on the west coast of Nosy Be, where foraging aggregations of large filter feeders (primarily R. typus and B. omurai) were frequently observed. Only SST had a significant effect on the relative abundance of animals in the predator feeding guild, which demonstrated a more longitudinal distribution along the continental shelf. The maximum entropy model (Maxent) was used for predicting habitat preference for the most frequently sighted species (Chapter 3). The distribution of whale sharks, mobulid rays and Omura’s whales were significantly overlapped as they were abundant in two main hotspots, Grand banc de l’entrée (~10 km of the west coast) and near Nosy Mitsio island, (~50 km northeast of Nosy Be). Suitable habitat for the dolphins was in relatively shallow waters in temperatures <28ºC near areas of steep changes in bathymetry. Bottlenose and spinner dolphins had a more widespread distribution across the continental shelf and humpback dolphin was closely associated with inshore reefs and occur in waters <10m. The coastal and inshore region of Nosy Be is an important habitat for a variety of megafaunal species, and the continental shelf provided essential areas for feeding and breeding. The results were similar to those presented for these species in other regions of the Indian Ocean (i.e., Eastern and Southern Africa; Western Australia; Seychelles) as well as outside of the Indian Ocean (i.e., Indonesia; Caribbean; North Atlantic). Thus the results from this thesis could be considered for management recommendations for marine conservation in the region. The value and limitations of data collected by citizen science were outlined (Chapter 4). , Thesis (MSc) -- Faculty of Science, Zoology and Entomology, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Lubbé, Alicea
- Date: 2023-10-13
- Subjects: Marine animals Habitat Madagascar Nosy Be , Marine animals Geographical distribution Madagascar Nosy Be , Species distribution modelling , Maximum entropy method , Citizen science , Habitat preference
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424710 , vital:72177
- Description: Marine megafauna have important ecological roles including the top-down regulation of lower trophic levels and the transport of nutrients. They are also charismatic species of socioeconomic importance, due to their public appeal and focus for ecotourism. However, these taxa face numerous anthropogenic threats including bycatch, habitat-loss, noise disturbance, prey reductions, pollution, and vessel traffic. Northwest Madagascar has been identified as an important marine mammal area and whale shark aggregation site, yet limited information on megafauna within Madagascar exists. In this thesis, I investigated the community structure, distribution trends, related environmental factors (Chapter 2) and predicted habitat suitability (Chapter 3) using a species distribution modelling approach for marine megafauna around Nosy Be, North-west Madagascar. Data collection consisted of opportunistic boatbased surveys conducted while looking for whale sharks, mobulid rays and cetaceans. These activities were performed by dedicated ‘swim with whale shark’ tourism operators, Les Baleines Rand'eau and Safari Baleine during tourism activities directed by the Madagascar Whale Shark Project over four years (2016-2019). A total of 1792 sightings were reported with 13 identified species, including elasmobranchs: whale shark, Rhincodon typus; spinetail mobula ray, Mobula japonica; giant oceanic manta ray, Manta birostris; shortfin devil ray, Mobula kuhlii; balaenids: humpback whale, Megaptera novaeangliae; Omura's whale, Balaenoptera omurai, delphinids: Indo-Pacific bottlenose dolphin, Tursiops aduncus; spinner dolphin, Stenella longirostris; pantropical spotted dolphin, Stenella attenuata; Indian ocean humpback dolphin, Sousa plumbea; false killer whale, Pseudorca crassidens; melonheaded whale, Peponocephala electra and one cheloniid species: leatherback sea turtle, Dermochelys coriacea. Sightings were spatially analysed at a community level according to feeding guilds (i.e., filter feeders vs. predators), and distribution of the megafauna groups v were compared to selected remotely sensed physico-chemical data (sea surface temperature and chlorophyll-a concentration) and bathymetry charts (depth and slope) using generalized linear models (Chapter 2). All four variables had a significant effect on filter feeder distribution. Spatial distribution of filter feeder sightings peaked at an area of steep underwater topography (18-50m; x slope=0.5%) located on the west coast of Nosy Be, where foraging aggregations of large filter feeders (primarily R. typus and B. omurai) were frequently observed. Only SST had a significant effect on the relative abundance of animals in the predator feeding guild, which demonstrated a more longitudinal distribution along the continental shelf. The maximum entropy model (Maxent) was used for predicting habitat preference for the most frequently sighted species (Chapter 3). The distribution of whale sharks, mobulid rays and Omura’s whales were significantly overlapped as they were abundant in two main hotspots, Grand banc de l’entrée (~10 km of the west coast) and near Nosy Mitsio island, (~50 km northeast of Nosy Be). Suitable habitat for the dolphins was in relatively shallow waters in temperatures <28ºC near areas of steep changes in bathymetry. Bottlenose and spinner dolphins had a more widespread distribution across the continental shelf and humpback dolphin was closely associated with inshore reefs and occur in waters <10m. The coastal and inshore region of Nosy Be is an important habitat for a variety of megafaunal species, and the continental shelf provided essential areas for feeding and breeding. The results were similar to those presented for these species in other regions of the Indian Ocean (i.e., Eastern and Southern Africa; Western Australia; Seychelles) as well as outside of the Indian Ocean (i.e., Indonesia; Caribbean; North Atlantic). Thus the results from this thesis could be considered for management recommendations for marine conservation in the region. The value and limitations of data collected by citizen science were outlined (Chapter 4). , Thesis (MSc) -- Faculty of Science, Zoology and Entomology, 2023
- Full Text:
- Date Issued: 2023-10-13
Empty adjectives and excessive intensifiers, or savvy discourse moves? A feminist critical discourse study of gender-based differences in the discourse of businesspeople on LinkedIn
- Authors: Schmauss, Lindsay Susannah
- Date: 2023-10-13
- Subjects: Corpora (Linguistics) , Critical discourse analysis , Intensification (Linguistics) , Women's language , Adjective , Politeness (Linguistics)
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/425111 , vital:72211
- Description: This Feminist Critical Discourse Analysis (FCDA) examines the use of ‘empty’ adjectives and the equative intensifier so in discourse on LinkedIn, a social network service (SNS) for businesspeople and professionals. These linguistic features soften the impact of what is said in ways that can conform with politeness norms that one should not impose a point of view but can also be negatively construed as weak, uncertain and unclear. The North American sociolinguist, Robin Tolmach Lakoff (1973, 1975, 2004), first associated these linguistic markers with a feminine register in her seminal work, Language and Women’s Place, arguing that there is a social expectation that women talk like a lady and follow politeness conventions, while the speech of men is not similarly constrained. That women are socially conditioned to speak in ways that can undermine their clarity and assertiveness would present a particular dilemma in the business context, where clear, direct and confident communication is valued. This corpus-based study explores the dilemma in the context of LinkedIn where the linguistic behaviour of cisgender women indeed showed evidence of their struggle between conflicting impulses to talk like a lady and a desire to be taken seriously as businesspeople. While the examined features mainly appeared in the discourse of women, it was interesting to note men making use of ‘empty’ adjectives and so in communication contexts where the goal appeared to be relationship-building. As notions of business leadership are evolving to value organisational leadership more, this suggests that linguistic devices that have traditionally been associated more with the communal conversation of the stereotypical ‘woman’ appear to be gaining wider acceptance and relevance, although in domains orientated towards the “soft skill” of building relationships, rather than the “hard work” of business. While the value talking like a lady may be shifting, language that is the opposite of talking like a lady seems to remain the language of serious talk, and the kind of gender-based linguistic discrimination first theorised by Lakoff seems thus to persist, also in the sphere of business discourse. , Thesis (MA) -- Faculty of Humanities, Linguistics and Applied Language Studies, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Schmauss, Lindsay Susannah
- Date: 2023-10-13
- Subjects: Corpora (Linguistics) , Critical discourse analysis , Intensification (Linguistics) , Women's language , Adjective , Politeness (Linguistics)
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/425111 , vital:72211
- Description: This Feminist Critical Discourse Analysis (FCDA) examines the use of ‘empty’ adjectives and the equative intensifier so in discourse on LinkedIn, a social network service (SNS) for businesspeople and professionals. These linguistic features soften the impact of what is said in ways that can conform with politeness norms that one should not impose a point of view but can also be negatively construed as weak, uncertain and unclear. The North American sociolinguist, Robin Tolmach Lakoff (1973, 1975, 2004), first associated these linguistic markers with a feminine register in her seminal work, Language and Women’s Place, arguing that there is a social expectation that women talk like a lady and follow politeness conventions, while the speech of men is not similarly constrained. That women are socially conditioned to speak in ways that can undermine their clarity and assertiveness would present a particular dilemma in the business context, where clear, direct and confident communication is valued. This corpus-based study explores the dilemma in the context of LinkedIn where the linguistic behaviour of cisgender women indeed showed evidence of their struggle between conflicting impulses to talk like a lady and a desire to be taken seriously as businesspeople. While the examined features mainly appeared in the discourse of women, it was interesting to note men making use of ‘empty’ adjectives and so in communication contexts where the goal appeared to be relationship-building. As notions of business leadership are evolving to value organisational leadership more, this suggests that linguistic devices that have traditionally been associated more with the communal conversation of the stereotypical ‘woman’ appear to be gaining wider acceptance and relevance, although in domains orientated towards the “soft skill” of building relationships, rather than the “hard work” of business. While the value talking like a lady may be shifting, language that is the opposite of talking like a lady seems to remain the language of serious talk, and the kind of gender-based linguistic discrimination first theorised by Lakoff seems thus to persist, also in the sphere of business discourse. , Thesis (MA) -- Faculty of Humanities, Linguistics and Applied Language Studies, 2023
- Full Text:
- Date Issued: 2023-10-13
Esibelekweni: Ingqokelela Yemibongo ngesiXhosa nangesiNgesi
- Authors: Busakwe, Yenzokuhle
- Date: 2023-10-13
- Subjects: Creative writing (Higher education) South Africa , Diaries Authorship , Books Reviews , South African essays (English) 21st century , Xhosa poetry 21st century
- Language: English , Xhosa
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424917 , vital:72193
- Description: My thesis is a collection of poems that is written in isiXhosa and English. It explores African spirituality, my relationship with God, heartache from romantic and platonic relationships. I make use of dual languages because some themes that I write about such as African spirituality I find words that capture their truest emotion in my Xhosa vocabulary, and I cannot find them in English. My poems use the narrative form because it allows me to tell stories through poetry without having to commit my writing to musicality or rhyming that a lyric poetry normally has. My work is shaped by writers such as Kate Beinhemer, Mangaliso Buzani, Amy Saul Zerby, Nontsizi Mgqwethio, Simphiwe Nolutshungu and Oiu Miaojin. Buzani makes use of images and few lines in his writing but still manages to capture a story with brevity. Saul-Zerby makes use of text lingo in some of her poems, and I make use of it to close a gap that I have identified with the books that I was reading that are all written in a formal and serious format. Mgqwetho’s poems explore Christianity and African Spirituality which is one of the subjects that my work is exploring too but in a manner that differs. I talk about how they have been my guidance instead of praising their powers like Nontsizi normally does in her poems. Simphiwe Nolutshungu’s poems has influenced the structure of my poems. Fairy tales written by writers like Kate helps my writing to bring to life issues that sound too dreamy to be true but have manifested as visions and memories that I cannot wipe out from my conscience. Oiu Miaojin’s novel “Last words from Montmantre” I am fascinated by how the writer detail emotions such as vulnerability and heartbreak in his storytelling. , Thesis (MA) -- Faculty of Humanities, School of Languages and Literatures, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Busakwe, Yenzokuhle
- Date: 2023-10-13
- Subjects: Creative writing (Higher education) South Africa , Diaries Authorship , Books Reviews , South African essays (English) 21st century , Xhosa poetry 21st century
- Language: English , Xhosa
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424917 , vital:72193
- Description: My thesis is a collection of poems that is written in isiXhosa and English. It explores African spirituality, my relationship with God, heartache from romantic and platonic relationships. I make use of dual languages because some themes that I write about such as African spirituality I find words that capture their truest emotion in my Xhosa vocabulary, and I cannot find them in English. My poems use the narrative form because it allows me to tell stories through poetry without having to commit my writing to musicality or rhyming that a lyric poetry normally has. My work is shaped by writers such as Kate Beinhemer, Mangaliso Buzani, Amy Saul Zerby, Nontsizi Mgqwethio, Simphiwe Nolutshungu and Oiu Miaojin. Buzani makes use of images and few lines in his writing but still manages to capture a story with brevity. Saul-Zerby makes use of text lingo in some of her poems, and I make use of it to close a gap that I have identified with the books that I was reading that are all written in a formal and serious format. Mgqwetho’s poems explore Christianity and African Spirituality which is one of the subjects that my work is exploring too but in a manner that differs. I talk about how they have been my guidance instead of praising their powers like Nontsizi normally does in her poems. Simphiwe Nolutshungu’s poems has influenced the structure of my poems. Fairy tales written by writers like Kate helps my writing to bring to life issues that sound too dreamy to be true but have manifested as visions and memories that I cannot wipe out from my conscience. Oiu Miaojin’s novel “Last words from Montmantre” I am fascinated by how the writer detail emotions such as vulnerability and heartbreak in his storytelling. , Thesis (MA) -- Faculty of Humanities, School of Languages and Literatures, 2023
- Full Text:
- Date Issued: 2023-10-13
Exploring the drivers of co-occurring multiple non-native fish assemblages within an invaded and flow-modified African river system
- Authors: Mpopetsi, Pule Peter
- Date: 2023-10-13
- Subjects: Freshwater ecology , Invasion biology , Freshwater fishes South Africa Great Fish River Estuary , Functional trait , Functional diversity , Introduced fishes South Africa Great Fish River Estuary , Food chains (Ecology)
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/431871 , vital:72810 , DOI 10.21504/10962/431871
- Description: Globally, there is growing concern on the negative impacts of species invasions and habitat disturbance because these have been shown to have the potential to disrupt native community structure and function. In some instances, these two stressors can occur in concert, such as in river systems associated with inter-basin water transfer (IBWT) schemes. The Great Fish River in the Eastern Cape, South Africa, is an example of a system affected by both habitat modification and multiple fish invasions largely because of an IBWT scheme. The opening of the Orange-Fish IBWT, which transfers water from the Orange River to the Great Fish River, modified the latter’s natural flow regime from irregular seasonal to perennial. In addition, the IBWT facilitated translocations of five fish species from the Gariep Dam (Orange River system) into the Great Fish River system. Proliferation of these non-native fish species, along with that of other fish species introduced for angling and biological control, raise questions on the mechanisms facilitating their existence within this highly modified river system. This thesis explored mechanisms associated with co-occurrences of these multiple non-native fishes within the Great Fish River. A comparison of historical and contemporary records on the ichthyofauna of the Great Fish River revealed that, of the 11 non-native fishes reported in this system, seven have established successfully, three have failed to establish and the status of one was uncertain. The Orange-Fish IBWT and angling were the main vectors of these invasions, accounting for 36% and 46%, respectively. The study also found that most established non-native fish species were large sized, had high longevity and wide habitat tolerance. Trait-based approaches were employed to investigate the role of functional diversity of non-native and native fishes in relation to their composition, distribution and environmental relationships. Although considerable interspecific variation in body morphology-related functional traits among species were observed, there was no clear distinction in these traits between native and non-native fish assemblages on a trait-ordination space. Furthermore, there were weak species-trait-environment relationships, suggesting that environmental filtering was less plausible in explaining the occurrence patterns of these fishes. Stable isotope-based trophic relationships were evaluated in three invaded sections: the upper (UGFR) mainstem sections of the Great Fish River; and lower (LGFR) mainstem sections of the Great Fish River; and its tributary, the Koonap River. It was observed that native and non-native fish assemblages exhibited variation in isotopic diversity typified by low isotopic diversity overlaps in UGFR and Koonap River, whereas the LGFR was characterised by high isotopic diversity overlap. Within the invaded sections, non-native fishes were found to have isotopic niches characterised by variable isotopic niche sizes and were more isotopically dissimilar with propensity towards trophic differentiation within the UGFR and Koonap River but were mostly characterised by high isotope niche overlaps in the LGFR. Overall, these results provided evidence of trophic niche differentiation as a probable mechanism associated with the co-occurrences of the non-native fishes. However, mechanisms facilitating these co-occurrences within the invaded sections appears to be complex, context-specific and, in some cases, unclear. Lastly, machine learning techniques, boosted (BRT) and multivariate (MRT) regression trees, revealed that the flow-disturbed habitats were invaded by multiple non-native species, whereas the non-disturbed headwaters remained invasion free. In addition, non-native species were predicted to co-occur with native species within the mainstem and large tributary sections of the Great Fish River system. Thus, the IBWT-disturbed mainstem sections were predicted to be more prone to multiple invasions compared to undisturbed headwater tributaries. , Tlhaselo ka mefuta ya diphoofolo-tsa-matswantle (non-native species), ha mmoho le phetolo/tsenyehelo ya bodulo ba diphoofolo-tsa-lehae (native species), di nkuwa ele tse pedi tsa tse kgolo ka ho fetisisa hara ditshoso tse kgahlanong le paballo kapa tshireletso ya diphoofolo-tsa-lehae tse phelang dinokeng kapa metsing. Maemong a mang, dikgatello tsena tse pedi dika etsahala ka nako e le nngwe, jwalo ka dinokeng tseo di amanang le maano a ho fetisa/tsamaisa metsi pakeng tsa dinoka tse fapa-fapaneng (IBWT). Enngwe ya dinoka tse jwalo, ke noka e bitswang ka Great Fish River, e fumanehang Kapa-Botjabela (Eastern Cape) ka hara naha ya Afrika Borwa (South Africa). Noka ena ya Great Fish River e angwa ke tshenyehelo ya bodulo ba ditlhapi-tsa-lehae, ha mmoho le tlhaselo ya tsona ka ditlhapi-tsa-matswantle. Tsena di etsahala hahololo ka lebaka la morero kapa leano la phepelo ya metsi le bitswang Orange-Fish IBWT, leo lona le ileng la fetola phallo ya tlhaho ya metsi a Great Fish River. Ho feta moo, leano lena la phephelo yametsi, Orange-Fish IBWT, le entse hore ho be bonolo ho fetisetswa ha mefuta e mehlano ya ditlhapi-tsa-matswantle ho tloha letamong le bitswang Gariep Dam, hoya kena ka hara noka ya Great Fish River. Ditla morao tsa tsena tsohle, ebile ho ata ha mefuta e mengata ya ditlhapi-tsa-matswantle ka hara noka ya Great Fish River. Ho ata hona ha ditlapi-tsa-matswantle ka hara noka ena ya Great Fish River, ho hlahisa dipotso mabapi le mekgwa e bebofatsang ho phela ha ditlhapi tsena tsa matswantle ka hara noka ena; hore ana ebe diphela jwang ka hara noka ya Great Fish River? Ka hona, sepheo le merero wa thuto ena ke ho phuputsa mekgwa e bebofatsang ho phela ha mefuta ena e fapaneng ya ditlhapi-tsa-matswantle ka hara noka ya Great Fish River. Dipheto tsa diphuputso di hlalosa hore, ha jwale, ka hara noka ena ya Great Fish River, hona le ditlhapi-tsa-matswantle tse leshome le motso o mong (11). Bosupa (7) ba tsona di phela ka katleho, ha tse tharo di hlolehile ho theha (3), mme e le nngwe (1) boemo ba teng ha bo hlake. Hare lekola hore ke efeng mekgwa e amanang le ho ata ha ditlhapi-tsa-matswantle ka hara Great Fish River, re fumana hore leano la phephelo ya metsi la Orange-Fish IBWT ka 36%, ha mmoho le boithapollo ba ho tshwasa ditlhapi (angling) ka 46%, ene ele tsona tsela tsa ho kena ha ditlhapi-tsa-matswantle ka hara Great Fish River, tse ka sehlohong. Re fumantsha hape hore katleho ya ditlhapi-tsa-matswantle e amahangwa le hore di boholo bo bokae, le hore diphela nako e ka kang. Mohlala, ditlhapi tse kgolo tse phelang nako etelele ka tlhaho ya tsona, di amahangwa le katleho ya ho theha ka hara noka ena. Ha tseo tse phelang nako e kgutshwanyane tsona disa amahangwe leho atleha ka hara noka ena. Tse ding tsa dipheto di hlalosa hore, ditlhapi-tsa-lehae le ditlhapi-tsa-matswantle, ka karolelano, hadi fapane haholo ka dibopeho tsa mmele, dihlopa tsena tse pedi diya tshwana. Re fumantsha hape hore dihlopa tsena tse pedi tsa ditlapi dija mefuta e fapaneng ya dijo. Eleng engwe ya dintho tse netefatsang katleho ya ditlhapi-tsa-matswantle ka hara noka ena ya Great fish river. Hona keka lebaka la hore, dihlopa tsena tse pedi hadi bakisane dijo, empa di phela ka mefuta e fapaneng ya dijo. Hare phethela, re fumantsha hore mefuta e fapafapaneng ya ditlhapi-tsa-matswantle e fumaneha feela ka hara madulo a amahangwang le phethoho ya phallo ya metsi (flow alteration), madulo asa amahangwang le phetoho ya phallo ya metsi ona ane a hloka ditlhapi-tsa-matswantle. Sena se bolela hore phetolo ya phallo ya metsi ya Great Fish River, ka lebaka la Orange-Fish IBWT, e fokoditse matla a noka ena ho lwantsha tlhaselo ya ditlhapi-tsa-matswantle. Ka hona, ho bobebe hore ditlhapi-tsa-matswantle di thehe ka katleho ka hara noka ena. Tsena tsohle keka baka la phetolo ya phallo ya metsi a Great Fish River e bakilweng ke leano la phephelo ya metsi la Orange-Fish IBWT. , Thesis (PhD) -- Faculty of Science, Faculty of Science, Ichthyology and Fisheries Science, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Mpopetsi, Pule Peter
- Date: 2023-10-13
- Subjects: Freshwater ecology , Invasion biology , Freshwater fishes South Africa Great Fish River Estuary , Functional trait , Functional diversity , Introduced fishes South Africa Great Fish River Estuary , Food chains (Ecology)
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/431871 , vital:72810 , DOI 10.21504/10962/431871
- Description: Globally, there is growing concern on the negative impacts of species invasions and habitat disturbance because these have been shown to have the potential to disrupt native community structure and function. In some instances, these two stressors can occur in concert, such as in river systems associated with inter-basin water transfer (IBWT) schemes. The Great Fish River in the Eastern Cape, South Africa, is an example of a system affected by both habitat modification and multiple fish invasions largely because of an IBWT scheme. The opening of the Orange-Fish IBWT, which transfers water from the Orange River to the Great Fish River, modified the latter’s natural flow regime from irregular seasonal to perennial. In addition, the IBWT facilitated translocations of five fish species from the Gariep Dam (Orange River system) into the Great Fish River system. Proliferation of these non-native fish species, along with that of other fish species introduced for angling and biological control, raise questions on the mechanisms facilitating their existence within this highly modified river system. This thesis explored mechanisms associated with co-occurrences of these multiple non-native fishes within the Great Fish River. A comparison of historical and contemporary records on the ichthyofauna of the Great Fish River revealed that, of the 11 non-native fishes reported in this system, seven have established successfully, three have failed to establish and the status of one was uncertain. The Orange-Fish IBWT and angling were the main vectors of these invasions, accounting for 36% and 46%, respectively. The study also found that most established non-native fish species were large sized, had high longevity and wide habitat tolerance. Trait-based approaches were employed to investigate the role of functional diversity of non-native and native fishes in relation to their composition, distribution and environmental relationships. Although considerable interspecific variation in body morphology-related functional traits among species were observed, there was no clear distinction in these traits between native and non-native fish assemblages on a trait-ordination space. Furthermore, there were weak species-trait-environment relationships, suggesting that environmental filtering was less plausible in explaining the occurrence patterns of these fishes. Stable isotope-based trophic relationships were evaluated in three invaded sections: the upper (UGFR) mainstem sections of the Great Fish River; and lower (LGFR) mainstem sections of the Great Fish River; and its tributary, the Koonap River. It was observed that native and non-native fish assemblages exhibited variation in isotopic diversity typified by low isotopic diversity overlaps in UGFR and Koonap River, whereas the LGFR was characterised by high isotopic diversity overlap. Within the invaded sections, non-native fishes were found to have isotopic niches characterised by variable isotopic niche sizes and were more isotopically dissimilar with propensity towards trophic differentiation within the UGFR and Koonap River but were mostly characterised by high isotope niche overlaps in the LGFR. Overall, these results provided evidence of trophic niche differentiation as a probable mechanism associated with the co-occurrences of the non-native fishes. However, mechanisms facilitating these co-occurrences within the invaded sections appears to be complex, context-specific and, in some cases, unclear. Lastly, machine learning techniques, boosted (BRT) and multivariate (MRT) regression trees, revealed that the flow-disturbed habitats were invaded by multiple non-native species, whereas the non-disturbed headwaters remained invasion free. In addition, non-native species were predicted to co-occur with native species within the mainstem and large tributary sections of the Great Fish River system. Thus, the IBWT-disturbed mainstem sections were predicted to be more prone to multiple invasions compared to undisturbed headwater tributaries. , Tlhaselo ka mefuta ya diphoofolo-tsa-matswantle (non-native species), ha mmoho le phetolo/tsenyehelo ya bodulo ba diphoofolo-tsa-lehae (native species), di nkuwa ele tse pedi tsa tse kgolo ka ho fetisisa hara ditshoso tse kgahlanong le paballo kapa tshireletso ya diphoofolo-tsa-lehae tse phelang dinokeng kapa metsing. Maemong a mang, dikgatello tsena tse pedi dika etsahala ka nako e le nngwe, jwalo ka dinokeng tseo di amanang le maano a ho fetisa/tsamaisa metsi pakeng tsa dinoka tse fapa-fapaneng (IBWT). Enngwe ya dinoka tse jwalo, ke noka e bitswang ka Great Fish River, e fumanehang Kapa-Botjabela (Eastern Cape) ka hara naha ya Afrika Borwa (South Africa). Noka ena ya Great Fish River e angwa ke tshenyehelo ya bodulo ba ditlhapi-tsa-lehae, ha mmoho le tlhaselo ya tsona ka ditlhapi-tsa-matswantle. Tsena di etsahala hahololo ka lebaka la morero kapa leano la phepelo ya metsi le bitswang Orange-Fish IBWT, leo lona le ileng la fetola phallo ya tlhaho ya metsi a Great Fish River. Ho feta moo, leano lena la phephelo yametsi, Orange-Fish IBWT, le entse hore ho be bonolo ho fetisetswa ha mefuta e mehlano ya ditlhapi-tsa-matswantle ho tloha letamong le bitswang Gariep Dam, hoya kena ka hara noka ya Great Fish River. Ditla morao tsa tsena tsohle, ebile ho ata ha mefuta e mengata ya ditlhapi-tsa-matswantle ka hara noka ya Great Fish River. Ho ata hona ha ditlapi-tsa-matswantle ka hara noka ena ya Great Fish River, ho hlahisa dipotso mabapi le mekgwa e bebofatsang ho phela ha ditlhapi tsena tsa matswantle ka hara noka ena; hore ana ebe diphela jwang ka hara noka ya Great Fish River? Ka hona, sepheo le merero wa thuto ena ke ho phuputsa mekgwa e bebofatsang ho phela ha mefuta ena e fapaneng ya ditlhapi-tsa-matswantle ka hara noka ya Great Fish River. Dipheto tsa diphuputso di hlalosa hore, ha jwale, ka hara noka ena ya Great Fish River, hona le ditlhapi-tsa-matswantle tse leshome le motso o mong (11). Bosupa (7) ba tsona di phela ka katleho, ha tse tharo di hlolehile ho theha (3), mme e le nngwe (1) boemo ba teng ha bo hlake. Hare lekola hore ke efeng mekgwa e amanang le ho ata ha ditlhapi-tsa-matswantle ka hara Great Fish River, re fumana hore leano la phephelo ya metsi la Orange-Fish IBWT ka 36%, ha mmoho le boithapollo ba ho tshwasa ditlhapi (angling) ka 46%, ene ele tsona tsela tsa ho kena ha ditlhapi-tsa-matswantle ka hara Great Fish River, tse ka sehlohong. Re fumantsha hape hore katleho ya ditlhapi-tsa-matswantle e amahangwa le hore di boholo bo bokae, le hore diphela nako e ka kang. Mohlala, ditlhapi tse kgolo tse phelang nako etelele ka tlhaho ya tsona, di amahangwa le katleho ya ho theha ka hara noka ena. Ha tseo tse phelang nako e kgutshwanyane tsona disa amahangwe leho atleha ka hara noka ena. Tse ding tsa dipheto di hlalosa hore, ditlhapi-tsa-lehae le ditlhapi-tsa-matswantle, ka karolelano, hadi fapane haholo ka dibopeho tsa mmele, dihlopa tsena tse pedi diya tshwana. Re fumantsha hape hore dihlopa tsena tse pedi tsa ditlapi dija mefuta e fapaneng ya dijo. Eleng engwe ya dintho tse netefatsang katleho ya ditlhapi-tsa-matswantle ka hara noka ena ya Great fish river. Hona keka lebaka la hore, dihlopa tsena tse pedi hadi bakisane dijo, empa di phela ka mefuta e fapaneng ya dijo. Hare phethela, re fumantsha hore mefuta e fapafapaneng ya ditlhapi-tsa-matswantle e fumaneha feela ka hara madulo a amahangwang le phethoho ya phallo ya metsi (flow alteration), madulo asa amahangwang le phetoho ya phallo ya metsi ona ane a hloka ditlhapi-tsa-matswantle. Sena se bolela hore phetolo ya phallo ya metsi ya Great Fish River, ka lebaka la Orange-Fish IBWT, e fokoditse matla a noka ena ho lwantsha tlhaselo ya ditlhapi-tsa-matswantle. Ka hona, ho bobebe hore ditlhapi-tsa-matswantle di thehe ka katleho ka hara noka ena. Tsena tsohle keka baka la phetolo ya phallo ya metsi a Great Fish River e bakilweng ke leano la phephelo ya metsi la Orange-Fish IBWT. , Thesis (PhD) -- Faculty of Science, Faculty of Science, Ichthyology and Fisheries Science, 2023
- Full Text:
- Date Issued: 2023-10-13
Investigating teachers’ perceptions on translanguaging pedagogy in a multilingual intermediate ESL classroom: a comparative study of two primary schools in Namibia
- Authors: Rheeder, Veneza Memory
- Date: 2023-10-13
- Subjects: Translanguaging (Linguistics) , Second language acquisition , Multilingual education Namibia , Primary school teachers Attitudes , Native language and education Namibia , Primary school teaching Namibia
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/419760 , vital:71673
- Description: International literature has tested the effectiveness of translanguaging as a pedagogic tool to enhance learning in a bilingual classroom; however, with the recent curriculum reform and education sector policy, there is no direct claim in the National policy frameworks on the prominence of translanguaging as an effective tool in classroom pedagogy in Namibian schools. This research attempted to investigate the role of translanguaging as a pedagogic tool to enhance learning in the multilingual intermediate English Second Language (ESL) phase as the Language of Learning and Teaching (LoLT) for the intermediate phase, Grades 4-7, in the Erongo Region, Namibia. The study is within the interpretive paradigm and adopts a qualitative methodology using a qualitative multi-case study approach of exploring and understanding differences and similarities between cases. Data collection consisted mainly of open-ended interviews and observations (purposive sampling) of the participating teachers. The research sites and study participants were purposely selected as both schools, diversely located in urban and rural contexts of the region, are enacting the National Language Policy as proposed. This entails using Mother Tongue Instruction (MTI) from Grades 0-3 and then transitioning to English-monolingual instruction from Grades 4 onwards. The study was designed to investigate the role of translanguaging pedagogy in enhancing learning in the Second Language (L2) classroom, without prejudice of social classes - the elite and marginalized communities. It investigated the extent to which teachers’ use of translanguaging pedagogy enhances ESL learning as the LoLT to intermediate phase learners transitioning from MTI to English-only instruction. The main theories underpinning this study are the Vygotskian and Translanguaging theories supported by Krashen and Cummins’ Cognitive Underlying Proficiency (CUP) Model. The outcomes of the study reveal that in both schools translanguaging was supported by content subject teachers and English LoLT teachers and that it positively contributed to improving learner understanding of important concepts in several subjects. However, Mother Tongue (MT) teachers did not support the use of translanguaging and believed that it slowed down the learning of English. , Thesis (MEd) -- Faculty of Education, Institute for the Study of Englishes in Africa, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Rheeder, Veneza Memory
- Date: 2023-10-13
- Subjects: Translanguaging (Linguistics) , Second language acquisition , Multilingual education Namibia , Primary school teachers Attitudes , Native language and education Namibia , Primary school teaching Namibia
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/419760 , vital:71673
- Description: International literature has tested the effectiveness of translanguaging as a pedagogic tool to enhance learning in a bilingual classroom; however, with the recent curriculum reform and education sector policy, there is no direct claim in the National policy frameworks on the prominence of translanguaging as an effective tool in classroom pedagogy in Namibian schools. This research attempted to investigate the role of translanguaging as a pedagogic tool to enhance learning in the multilingual intermediate English Second Language (ESL) phase as the Language of Learning and Teaching (LoLT) for the intermediate phase, Grades 4-7, in the Erongo Region, Namibia. The study is within the interpretive paradigm and adopts a qualitative methodology using a qualitative multi-case study approach of exploring and understanding differences and similarities between cases. Data collection consisted mainly of open-ended interviews and observations (purposive sampling) of the participating teachers. The research sites and study participants were purposely selected as both schools, diversely located in urban and rural contexts of the region, are enacting the National Language Policy as proposed. This entails using Mother Tongue Instruction (MTI) from Grades 0-3 and then transitioning to English-monolingual instruction from Grades 4 onwards. The study was designed to investigate the role of translanguaging pedagogy in enhancing learning in the Second Language (L2) classroom, without prejudice of social classes - the elite and marginalized communities. It investigated the extent to which teachers’ use of translanguaging pedagogy enhances ESL learning as the LoLT to intermediate phase learners transitioning from MTI to English-only instruction. The main theories underpinning this study are the Vygotskian and Translanguaging theories supported by Krashen and Cummins’ Cognitive Underlying Proficiency (CUP) Model. The outcomes of the study reveal that in both schools translanguaging was supported by content subject teachers and English LoLT teachers and that it positively contributed to improving learner understanding of important concepts in several subjects. However, Mother Tongue (MT) teachers did not support the use of translanguaging and believed that it slowed down the learning of English. , Thesis (MEd) -- Faculty of Education, Institute for the Study of Englishes in Africa, 2023
- Full Text:
- Date Issued: 2023-10-13
InVisible freedom fighter: a critical analysis of portrayals of women in archival photographs, independence monuments and contemporary art in Zambia (Northern Rhodesia) and Zimbabwe (Southern Rhodesia)
- Authors: Kalichini, Gladys Melina
- Date: 2023-10-13
- Subjects: Women in art , Art History , Art Political aspects Zambia , Art Political aspects Zimbabwe , Revolutionaries in art , Visual culture
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/432433 , vital:72870 , DOI 10.21504/10962/432433
- Description: This doctoral dissertation in art history develops a notion of invisibility by critically analysing processes in which narratives about women are either concealed or uncovered in visual portrayals relating to the independence of Zambia (former Northern Rhodesia) and Zimbabwe (previously Southern Rhodesia). This study concentrates on three main visual categories that include archival photographs, national monuments, and visual art. It critically engages with concepts of memory and history through a framework of gender. The concept of invisibility developed in this thesis articulates a dynamic process in which independence narratives evolve over time, sometimes revealing memories associated with women and at other times rendering women invisible. National liberation in many African states is dominantly accredited to the political parties that were in power at the time of independence. In Zambia, the United National Independence Party (UNIP) is acknowledged for spearheading efforts to overthrow the colonial administration, while in Zimbabwe it is the Zimbabwe African National Union – Patriotic Front (ZANU – PF). Both political parties were headed by men, and the majority of their memberships was also comprised of men; as such, the dominant narratives largely illuminate the stories of men associated with these political parties. The overarching argument of this doctoral dissertation is that there is a gender bias inherent in dominant independence struggles narratives that are communicated through cultural heritage sites such as monuments and archives. In this study, art and art making inform theory as the methodological approach takes the direction in which selected artworks and visual materials are employed as a starting point of considering concepts that relate to the visibilities of stories about women. This approach cogitates the function of art, visual culture, and art history in the production of knowledges that foster in-depth understandings of concepts that explain social phenomena such as historical erasure. This doctoral dissertation in art history is divided into two parts, A and B, that conceptually complement each other. In section A which comprises of chapters one and two, the study develops an alternative visual archive that surveys the involvements of six specific women in the attainment of national independence in their respective countries, and critically analyses the Freedom Statue in Zambia and the National Heroes Acre in Zimbabwe as monuments dedicated to commemorating the independence struggle in the two countries. In Chapters three to five which form the second section of this dissertation, the emphasis of the discussion is on how selected visual artworks of three selected artists disrupt, counter or engage with dominant historical accounts that either exclude or marginalise narratives about women. The three artists include myself, Gladys Kalichini, and Zimbabwean born artists Kudzanai Chiurai and Gresham Tapiwa Nyaude. This thesis offers a culturally rich conversation about visual representations of social, political and cultural roles women performed in the colonial times in Northern and Southern Rhodesia and gives insight into the evolution of the luminosity of contemporary performances of women’s social collectives in Zambia and Zimbabwe. , Thesis (PhD) -- Faculty of Humanities, Fine Art, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Kalichini, Gladys Melina
- Date: 2023-10-13
- Subjects: Women in art , Art History , Art Political aspects Zambia , Art Political aspects Zimbabwe , Revolutionaries in art , Visual culture
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/432433 , vital:72870 , DOI 10.21504/10962/432433
- Description: This doctoral dissertation in art history develops a notion of invisibility by critically analysing processes in which narratives about women are either concealed or uncovered in visual portrayals relating to the independence of Zambia (former Northern Rhodesia) and Zimbabwe (previously Southern Rhodesia). This study concentrates on three main visual categories that include archival photographs, national monuments, and visual art. It critically engages with concepts of memory and history through a framework of gender. The concept of invisibility developed in this thesis articulates a dynamic process in which independence narratives evolve over time, sometimes revealing memories associated with women and at other times rendering women invisible. National liberation in many African states is dominantly accredited to the political parties that were in power at the time of independence. In Zambia, the United National Independence Party (UNIP) is acknowledged for spearheading efforts to overthrow the colonial administration, while in Zimbabwe it is the Zimbabwe African National Union – Patriotic Front (ZANU – PF). Both political parties were headed by men, and the majority of their memberships was also comprised of men; as such, the dominant narratives largely illuminate the stories of men associated with these political parties. The overarching argument of this doctoral dissertation is that there is a gender bias inherent in dominant independence struggles narratives that are communicated through cultural heritage sites such as monuments and archives. In this study, art and art making inform theory as the methodological approach takes the direction in which selected artworks and visual materials are employed as a starting point of considering concepts that relate to the visibilities of stories about women. This approach cogitates the function of art, visual culture, and art history in the production of knowledges that foster in-depth understandings of concepts that explain social phenomena such as historical erasure. This doctoral dissertation in art history is divided into two parts, A and B, that conceptually complement each other. In section A which comprises of chapters one and two, the study develops an alternative visual archive that surveys the involvements of six specific women in the attainment of national independence in their respective countries, and critically analyses the Freedom Statue in Zambia and the National Heroes Acre in Zimbabwe as monuments dedicated to commemorating the independence struggle in the two countries. In Chapters three to five which form the second section of this dissertation, the emphasis of the discussion is on how selected visual artworks of three selected artists disrupt, counter or engage with dominant historical accounts that either exclude or marginalise narratives about women. The three artists include myself, Gladys Kalichini, and Zimbabwean born artists Kudzanai Chiurai and Gresham Tapiwa Nyaude. This thesis offers a culturally rich conversation about visual representations of social, political and cultural roles women performed in the colonial times in Northern and Southern Rhodesia and gives insight into the evolution of the luminosity of contemporary performances of women’s social collectives in Zambia and Zimbabwe. , Thesis (PhD) -- Faculty of Humanities, Fine Art, 2023
- Full Text:
- Date Issued: 2023-10-13
Jazz pedagogical strategies: an A/R/Tographic investigation into the implementation of the South African jazz CAPS syllabus
- Authors: Rungan, Natalie
- Date: 2023-10-13
- Subjects: Jazz Instruction and study , Durban High School Curricula , Jazz Outlines, syllabi, etc. , Curriculum-based assessment South Africa , Jazz vocals , Jazz education , South Africa. Department of Basic Education
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/432488 , vital:72875 , DOI 10.21504/10962/432488
- Description: The Jazz stream of the Curriculum and Assessment Policy Statement Further Education and Training music curriculum was introduced in South Africa in 2012 (DBE, 2011a). Despite the intentions of the government to promote diversity, social transformation, and inclusion, subject music is still weighted towards Western Art Music, perpetuating past biases of a Eurocentric model for music education. This study, which uses a mixed-method approach, seeks to create strategies to advance Jazz education in South Africa through an a/r/tographic analysis of the author’s Jazz pedagogical methods at Durban High School in KwaZulu Natal, South Africa. Key approaches include curriculum theory, currere, a/r/tography, among others. After reviewing Jazz pedagogy in the U.S.A. and South Africa as a starting point, using Pinar’s (1994) method of currere, the author demonstrates how past personal music educational processes have led to present Jazz pedagogical methods. Six original compositions were written that outline the influences that infused these methods and added to the creative output related to this research. Interviews were conducted with key stakeholders in the Jazz community to gain perspective about the current state of Jazz education, and with students to provide insight into their reactions to the Jazz stream of CAPS. This presents new information about the curriculum from a learners’ perspective. Ethical clearance for research with children was sought and received (Appendix A). Findings show that the ability of learners to recognise the value in, and identity relating to, their African culture through Jazz points to a pivotal departure from previous Eurocentric music education models. However, despite South Africa being positioned as one of the only countries offering Jazz as a subject choice to high school learners, the selection of Jazz in the subject of Music remains underutilised. This study concludes that for Jazz education to advance in South African high schools, there needs to be intentional engagement with Jazz professionals at the high school level. , Thesis (PhD) -- Faculty of Humanities, Music and Musicology, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Rungan, Natalie
- Date: 2023-10-13
- Subjects: Jazz Instruction and study , Durban High School Curricula , Jazz Outlines, syllabi, etc. , Curriculum-based assessment South Africa , Jazz vocals , Jazz education , South Africa. Department of Basic Education
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/432488 , vital:72875 , DOI 10.21504/10962/432488
- Description: The Jazz stream of the Curriculum and Assessment Policy Statement Further Education and Training music curriculum was introduced in South Africa in 2012 (DBE, 2011a). Despite the intentions of the government to promote diversity, social transformation, and inclusion, subject music is still weighted towards Western Art Music, perpetuating past biases of a Eurocentric model for music education. This study, which uses a mixed-method approach, seeks to create strategies to advance Jazz education in South Africa through an a/r/tographic analysis of the author’s Jazz pedagogical methods at Durban High School in KwaZulu Natal, South Africa. Key approaches include curriculum theory, currere, a/r/tography, among others. After reviewing Jazz pedagogy in the U.S.A. and South Africa as a starting point, using Pinar’s (1994) method of currere, the author demonstrates how past personal music educational processes have led to present Jazz pedagogical methods. Six original compositions were written that outline the influences that infused these methods and added to the creative output related to this research. Interviews were conducted with key stakeholders in the Jazz community to gain perspective about the current state of Jazz education, and with students to provide insight into their reactions to the Jazz stream of CAPS. This presents new information about the curriculum from a learners’ perspective. Ethical clearance for research with children was sought and received (Appendix A). Findings show that the ability of learners to recognise the value in, and identity relating to, their African culture through Jazz points to a pivotal departure from previous Eurocentric music education models. However, despite South Africa being positioned as one of the only countries offering Jazz as a subject choice to high school learners, the selection of Jazz in the subject of Music remains underutilised. This study concludes that for Jazz education to advance in South African high schools, there needs to be intentional engagement with Jazz professionals at the high school level. , Thesis (PhD) -- Faculty of Humanities, Music and Musicology, 2023
- Full Text:
- Date Issued: 2023-10-13
Lady Die
- Authors: Jephtas, Veronique Bianca
- Date: 2023-10-13
- Subjects: Creative writing (Higher education) South Africa , Kaaps , Books Reviews , South African fiction 21st century , Diaries Authorship
- Language: Afrikaans
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424928 , vital:72194
- Description: My tesis is geskryf in Kaaps en incorporate veskillende streeksvariante vannie taal. Die gedigte is hoofsaaklik innie dialek en ytie perspektief vannie spreker, Pamela geskryf. Tematies issie fokus die seksualiteit ennie inner workings vanne jong, bruinvrou wat haa feminine power probee assert in ’n patriarchal en invasive wêreld. Die bundel illustreer hierdie constant shifting power dynamics dee Pamela en haa vier boyfriends se vehoudings te examine. Wat vorm betref gebryk ek aspekte vannie zuihitsu, spesifiek die free movement tussen genre en styles: veskillende dele vannie bundel is geskryf as prose, poetry en kort, losstaande gedagtes. Ek kies die skryfstyl wattie narrative van oomblik tot oomblik die beste onnersteun, en beperk nie myself tot een consistent vorm nie ––oek kenmerkend van zuihitsu. Literêre invloede virrie teks is The Pillow Book dee Makura no Sōshi. Meer kontemporêre invloede is Kathy Acker, Marie Calloway, Nathan Trantraal en Ronelda S. Kamfer. Acker virrie manier wat sy identiteit illustreer, amper soese collage constructed yt seemingly unrelated stukkies teks en experiences; Calloway vi haa detached en unromanticised skrywe oo sex en vehoudings; Trantraal en Kamfer virrie manier waarop hulle universal stories vetel in ’n taal wat tightly bound is aan ’n baie spesifieke geography. , Thesis (MA) -- Faculty of Humanities, School of Languages and Literatures, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Jephtas, Veronique Bianca
- Date: 2023-10-13
- Subjects: Creative writing (Higher education) South Africa , Kaaps , Books Reviews , South African fiction 21st century , Diaries Authorship
- Language: Afrikaans
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424928 , vital:72194
- Description: My tesis is geskryf in Kaaps en incorporate veskillende streeksvariante vannie taal. Die gedigte is hoofsaaklik innie dialek en ytie perspektief vannie spreker, Pamela geskryf. Tematies issie fokus die seksualiteit ennie inner workings vanne jong, bruinvrou wat haa feminine power probee assert in ’n patriarchal en invasive wêreld. Die bundel illustreer hierdie constant shifting power dynamics dee Pamela en haa vier boyfriends se vehoudings te examine. Wat vorm betref gebryk ek aspekte vannie zuihitsu, spesifiek die free movement tussen genre en styles: veskillende dele vannie bundel is geskryf as prose, poetry en kort, losstaande gedagtes. Ek kies die skryfstyl wattie narrative van oomblik tot oomblik die beste onnersteun, en beperk nie myself tot een consistent vorm nie ––oek kenmerkend van zuihitsu. Literêre invloede virrie teks is The Pillow Book dee Makura no Sōshi. Meer kontemporêre invloede is Kathy Acker, Marie Calloway, Nathan Trantraal en Ronelda S. Kamfer. Acker virrie manier wat sy identiteit illustreer, amper soese collage constructed yt seemingly unrelated stukkies teks en experiences; Calloway vi haa detached en unromanticised skrywe oo sex en vehoudings; Trantraal en Kamfer virrie manier waarop hulle universal stories vetel in ’n taal wat tightly bound is aan ’n baie spesifieke geography. , Thesis (MA) -- Faculty of Humanities, School of Languages and Literatures, 2023
- Full Text:
- Date Issued: 2023-10-13
Phytoplankton and aquatic macroinvertebrate assemblages from coastal and inland lakes of South Africa
- Authors: Nkibi, Esethu
- Date: 2023-10-13
- Subjects: Aquatic biodiversity South Africa , Indicators (Biology) , Lakes South Africa , Physicochemical process , Salinity , Phytoplankton , Aquatic macroinvertebrates
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424435 , vital:72153
- Description: Freshwater lakes are generally defined as permanent natural standing water bodies, with some of them having a direct and indirect connection with groundwater, rivers, and the ocean. Freshwater lakes provide essential socio-economic and ecological goods and services including recreation, aesthetic, support aquatic biodiversity, food in a form of fisheries and water for domestic use. Given their critical role in sustainability in providing socio-economic services, freshwater lakes are among the most threatened ecosystems globally due to intense human impacts over the last decades. South Africa has limited freshwater lakes, which according to the National Biodiversity Assessment (NBA 2018), we know little about their current biology except historic aquatic biodiversity studies conducted in the early 1940s. There are no management strategies in place to protect and conserve freshwater lake biodiversity and important ecosystem services. This thesis aims to: (1) produce a biodiversity inventory of phytoplankton and aquatic macroinvertebrate species and, (2) investigate important environmental drivers responsible for phytoplankton and aquatic macroinvertebrate species composition from six South African freshwater lakes. It was hypothesized that the three lake types will show different phytoplankton and aquatic macroinvertebrates species composition attributed by the geographical region (coastal and inland lake) and related physico-chemical parameters. Study sites consisted of two Northern KwaZulu-Natal coastal lakes (hereafter Coastal Lakes, CL) i.e., Lake Sibaya, Lake Mzingazi; two fresh inland lakes (hereafter Fresh Inland Lakes, FIL) i.e., Lake Banagher fresh and Lake Tevrede Se Pan; and two inland salt lakes (hereafter Salt Inland Lakes, SIL) i.e., Lake Banagher salt and Lake Chrissiesmeer, all inland lakes are situated in Mpumalanga province, together with other Pans making up the Mpumalanga Lake District of South Africa. The study sites were categorized based on their geographical position i.e., coastal vs inland and physico-chemical characteristics i.e., the presence and absence of aquatic vegetation, dominate substrate, salinity and different physico-chemical concentration i.e., Temperature, Dissolved Oxygen. Aquatic macroinvertebrates were collected from four littoral zone sites (< 1-meter depth) around each lake, whereas phytoplankton samples were collected from four water column sites (> 5-meters depth) and (0.5-meter depth) from the water surface at each lake during summer and winter season. The results were consistent with our hypothesis that both phytoplankton and aquatic macroinvertebrate species composition were influenced by physico-chemical parameters and that the differences in salinity concentration and aquatic vegetation between CL, FIL, and SIL were the driving factors for phytoplankton and aquatic macroinvertebrate species composition. In summary, one hundred and twenty-two phytoplankton taxa were collected and identified during this study, belonging to seven Phyla which included Chlorophyta, Bacillariophyta, Cyanophyta, Chrysophyta, Dinophyta, Euglenophyta, and Cryptophyta. The most abundant phytoplankton groups were Bacillariophyta and Chlorophyta. Phytoplankton relative taxa abundance, Pielou’s evenness, taxa richness, and Shannon diversity were significantly different between lake types. Aquatic macroinvertebrates, on the other hand, summed up to 10 orders, 67 families, and 80 taxa. The most abundant group were the order Coleoptera, Hemiptera, Odonata, and Gastropoda. Aquatic macroinvertebrate relative taxa abundance, taxa richness, and Shannon diversity were also significantly different between lake types. Aquatic macroinvertebrate relative taxa abundance, Pielous evenness, and Shannon diversity index were not significant between seasons, and only taxa richness was significant. Canonical analysis of principal coordinates (CAP) results further showed unique and distinct phytoplankton and aquatic macroinvertebrates community composition between lake types. The present study provides baseline biodiversity inventory (or species list) for important lake ecosystems biological indicators i.e., phytoplankton and aquatic macroinvertebrates and species composition in relation to lake type for six freshwater lakes in South Africa. Furthermore, the study provides empirical evidence that will inform policy and the development of management strategies for freshwater lakes in South Africa which is currently missing. The current study will also contribute to the next National Biodiversity Assessment Report (2024), concerning the freshwater lakes biological data deficiency noted in the previous NBA (2018) report. The study will also fill up the gaps to better understand species composition in lake systems and how they function which is currently limited. , Thesis (MSc) -- Faculty of Science, Zoology and Entomology, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Nkibi, Esethu
- Date: 2023-10-13
- Subjects: Aquatic biodiversity South Africa , Indicators (Biology) , Lakes South Africa , Physicochemical process , Salinity , Phytoplankton , Aquatic macroinvertebrates
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424435 , vital:72153
- Description: Freshwater lakes are generally defined as permanent natural standing water bodies, with some of them having a direct and indirect connection with groundwater, rivers, and the ocean. Freshwater lakes provide essential socio-economic and ecological goods and services including recreation, aesthetic, support aquatic biodiversity, food in a form of fisheries and water for domestic use. Given their critical role in sustainability in providing socio-economic services, freshwater lakes are among the most threatened ecosystems globally due to intense human impacts over the last decades. South Africa has limited freshwater lakes, which according to the National Biodiversity Assessment (NBA 2018), we know little about their current biology except historic aquatic biodiversity studies conducted in the early 1940s. There are no management strategies in place to protect and conserve freshwater lake biodiversity and important ecosystem services. This thesis aims to: (1) produce a biodiversity inventory of phytoplankton and aquatic macroinvertebrate species and, (2) investigate important environmental drivers responsible for phytoplankton and aquatic macroinvertebrate species composition from six South African freshwater lakes. It was hypothesized that the three lake types will show different phytoplankton and aquatic macroinvertebrates species composition attributed by the geographical region (coastal and inland lake) and related physico-chemical parameters. Study sites consisted of two Northern KwaZulu-Natal coastal lakes (hereafter Coastal Lakes, CL) i.e., Lake Sibaya, Lake Mzingazi; two fresh inland lakes (hereafter Fresh Inland Lakes, FIL) i.e., Lake Banagher fresh and Lake Tevrede Se Pan; and two inland salt lakes (hereafter Salt Inland Lakes, SIL) i.e., Lake Banagher salt and Lake Chrissiesmeer, all inland lakes are situated in Mpumalanga province, together with other Pans making up the Mpumalanga Lake District of South Africa. The study sites were categorized based on their geographical position i.e., coastal vs inland and physico-chemical characteristics i.e., the presence and absence of aquatic vegetation, dominate substrate, salinity and different physico-chemical concentration i.e., Temperature, Dissolved Oxygen. Aquatic macroinvertebrates were collected from four littoral zone sites (< 1-meter depth) around each lake, whereas phytoplankton samples were collected from four water column sites (> 5-meters depth) and (0.5-meter depth) from the water surface at each lake during summer and winter season. The results were consistent with our hypothesis that both phytoplankton and aquatic macroinvertebrate species composition were influenced by physico-chemical parameters and that the differences in salinity concentration and aquatic vegetation between CL, FIL, and SIL were the driving factors for phytoplankton and aquatic macroinvertebrate species composition. In summary, one hundred and twenty-two phytoplankton taxa were collected and identified during this study, belonging to seven Phyla which included Chlorophyta, Bacillariophyta, Cyanophyta, Chrysophyta, Dinophyta, Euglenophyta, and Cryptophyta. The most abundant phytoplankton groups were Bacillariophyta and Chlorophyta. Phytoplankton relative taxa abundance, Pielou’s evenness, taxa richness, and Shannon diversity were significantly different between lake types. Aquatic macroinvertebrates, on the other hand, summed up to 10 orders, 67 families, and 80 taxa. The most abundant group were the order Coleoptera, Hemiptera, Odonata, and Gastropoda. Aquatic macroinvertebrate relative taxa abundance, taxa richness, and Shannon diversity were also significantly different between lake types. Aquatic macroinvertebrate relative taxa abundance, Pielous evenness, and Shannon diversity index were not significant between seasons, and only taxa richness was significant. Canonical analysis of principal coordinates (CAP) results further showed unique and distinct phytoplankton and aquatic macroinvertebrates community composition between lake types. The present study provides baseline biodiversity inventory (or species list) for important lake ecosystems biological indicators i.e., phytoplankton and aquatic macroinvertebrates and species composition in relation to lake type for six freshwater lakes in South Africa. Furthermore, the study provides empirical evidence that will inform policy and the development of management strategies for freshwater lakes in South Africa which is currently missing. The current study will also contribute to the next National Biodiversity Assessment Report (2024), concerning the freshwater lakes biological data deficiency noted in the previous NBA (2018) report. The study will also fill up the gaps to better understand species composition in lake systems and how they function which is currently limited. , Thesis (MSc) -- Faculty of Science, Zoology and Entomology, 2023
- Full Text:
- Date Issued: 2023-10-13