The use of filter-feeding fish (Clarias gariepinus and Oreochromis mossambicus) to remove microalgae from brewery effluent treatment ponds
- Authors: Nombembe, Lwazi
- Date: 2019
- Subjects: Clarias gariepinus -- Food , Mozambique tilapia -- Food , Water -- Purification -- South Africa , Algae -- Biotechnology -- South Africa , Microalgae -- Biotechnology-- South Africa , Brewery waste -- South Africa , Fish culture -- South Africa
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/95745 , vital:31194
- Description: The removal of microalgae from high rate algal ponds (HRAP) in waste-water treatment systems remains a constraint to their use in effluent treatment systems. Conventional algae harvesting methods often have high energy demands, take up lots of space, are expensive to operate or are time consuming. The aim of the study was to determine if fish such as Clarias gariepinus and Oreochromis mossambicus, could be used to remove microalgae from waste-water treatment ponds (in the absence/presence of a flocculent in the former and in the absence or presence of pH moderation in the latter), and to investigate the subsequent influence of algae concentration on several water quality parameters. The age of Clarias gariepinus (3-12 months) had a positive relationship with the distance between gill rakers (98.27 to 163.34 μm; y=90.576+4.823*x: R²=0.549; F(1,18)=21.867; p<0.001) and these data suggested that these fish might be efficient at removing algae from HRAP effluent. However, this was not the case, even with flocculent application (but this result might have been confounded by very high pH readings, at which flocculation is less likely to occur). Oreochromis mossambicus removed some of this algae, but the pH was too high for tilapia culture. It was not possible to moderate the increase in pH by keeping tanks in the dark and thus preventing photosynthesis; but pH fluctuation in HRAP effluent could be moderated using CO2 sparging in an attempt to make the environment more hospitable for tilapia (the average pH that was moderated with CO2 was 8.43±0.06, whereas the unmoderated average was 10.65±0.06). However, pH moderation using CO2 sparging did not increase the rate at which algae were removed by O. mossambicus; rather, it compromised O2 concentration which dropped to 4.17±1.26 mg/l after five hours of CO2 sparging, whereas it increased to 20.50±1.41 mg/l in treatments with unadjusted pH over the same period. Fish can be used to remove algae from treated effluent, and Oreochromis mossambicus remains a recommended species. Future work needs to investigate moderating fluctuations in pH and O2 concentration to further facilitate this method of algae removal.
- Full Text:
- Authors: Nombembe, Lwazi
- Date: 2019
- Subjects: Clarias gariepinus -- Food , Mozambique tilapia -- Food , Water -- Purification -- South Africa , Algae -- Biotechnology -- South Africa , Microalgae -- Biotechnology-- South Africa , Brewery waste -- South Africa , Fish culture -- South Africa
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/95745 , vital:31194
- Description: The removal of microalgae from high rate algal ponds (HRAP) in waste-water treatment systems remains a constraint to their use in effluent treatment systems. Conventional algae harvesting methods often have high energy demands, take up lots of space, are expensive to operate or are time consuming. The aim of the study was to determine if fish such as Clarias gariepinus and Oreochromis mossambicus, could be used to remove microalgae from waste-water treatment ponds (in the absence/presence of a flocculent in the former and in the absence or presence of pH moderation in the latter), and to investigate the subsequent influence of algae concentration on several water quality parameters. The age of Clarias gariepinus (3-12 months) had a positive relationship with the distance between gill rakers (98.27 to 163.34 μm; y=90.576+4.823*x: R²=0.549; F(1,18)=21.867; p<0.001) and these data suggested that these fish might be efficient at removing algae from HRAP effluent. However, this was not the case, even with flocculent application (but this result might have been confounded by very high pH readings, at which flocculation is less likely to occur). Oreochromis mossambicus removed some of this algae, but the pH was too high for tilapia culture. It was not possible to moderate the increase in pH by keeping tanks in the dark and thus preventing photosynthesis; but pH fluctuation in HRAP effluent could be moderated using CO2 sparging in an attempt to make the environment more hospitable for tilapia (the average pH that was moderated with CO2 was 8.43±0.06, whereas the unmoderated average was 10.65±0.06). However, pH moderation using CO2 sparging did not increase the rate at which algae were removed by O. mossambicus; rather, it compromised O2 concentration which dropped to 4.17±1.26 mg/l after five hours of CO2 sparging, whereas it increased to 20.50±1.41 mg/l in treatments with unadjusted pH over the same period. Fish can be used to remove algae from treated effluent, and Oreochromis mossambicus remains a recommended species. Future work needs to investigate moderating fluctuations in pH and O2 concentration to further facilitate this method of algae removal.
- Full Text:
The Zulu girl and other poems
- Authors: Ngidi, Sandile Brian
- Date: 2019
- Subjects: Xhosa poetry
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/92748 , vital:30744
- Description: My thesis is a collection of English poems that converse with Mazisi Kunene’s literary corpus. I draw from both Kunene’s early works, which followed the pioneering work of the Zulu poet BW Vilakazi, and his socio‐political later work, which is at once Pan African in scope and intent yet deeply rooted in a Zulu socio‐linguistic milieu. Like Kunene, I aim to create a poetics of exile by working between languages, writing in Zulu and then translating into English to express my alienation in South Africa and what it means to be exiled from language and culture and speak a foreign language with your mother tongue. Here, I also take influence from the rich, evocative imagery in Palestinian poet Mahmoud Darwish's poetry of exile and the quest for a lost homeland, as well as Brazilian poet Adela Prado’s wit and direct speech. I also engage popular contemporary forms of expression and use poetry to question some themes in the popular music genre maskandi, especially its rhetoric on identity, class and gender politics.
- Full Text:
- Authors: Ngidi, Sandile Brian
- Date: 2019
- Subjects: Xhosa poetry
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/92748 , vital:30744
- Description: My thesis is a collection of English poems that converse with Mazisi Kunene’s literary corpus. I draw from both Kunene’s early works, which followed the pioneering work of the Zulu poet BW Vilakazi, and his socio‐political later work, which is at once Pan African in scope and intent yet deeply rooted in a Zulu socio‐linguistic milieu. Like Kunene, I aim to create a poetics of exile by working between languages, writing in Zulu and then translating into English to express my alienation in South Africa and what it means to be exiled from language and culture and speak a foreign language with your mother tongue. Here, I also take influence from the rich, evocative imagery in Palestinian poet Mahmoud Darwish's poetry of exile and the quest for a lost homeland, as well as Brazilian poet Adela Prado’s wit and direct speech. I also engage popular contemporary forms of expression and use poetry to question some themes in the popular music genre maskandi, especially its rhetoric on identity, class and gender politics.
- Full Text:
Therefore I am
- Authors: Núñez-Lagos, Andres
- Date: 2019
- Subjects: South African fiction (English)
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/92737 , vital:30743
- Full Text:
- Authors: Núñez-Lagos, Andres
- Date: 2019
- Subjects: South African fiction (English)
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/92737 , vital:30743
- Full Text:
Time motion analyses of one-day international and twenty/20 matches and the development of a simulated batting protocol specifically designed for female cricket players
- Authors: Munro, Catherine
- Date: 2019
- Subjects: Women cricket players , Cricket -- Batting , Cricket -- Coaching , Cricket -- Physiological aspects
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/76342 , vital:30550
- Description: Background: Accurate and reliable in-game data is fundamental when designing effective batting training. A simulated batting protocol that could aid research and training has not been specifically designed for female cricketers because of a distinct lack of empirical in-game data for the women’s version of the game. Objective: The purpose of this study was to quantify the motion demands and run-breakdown of a century and T20 half-century for women’s cricket matches to establish a simulated batting protocol specifically designed for female batters. Method: Time-motion analyses of four one-day international and six T20 innings were conducted on international cricket matches played around the world between 2012 and 2017. The innings was divided into the bowling and batting innings. The ODI innings that met the criterion of 100 runs scored and T20 innings with scores above 50 runs were used in the run breakdown, which included scores from the top 10 countries ranked by the ICC. The time-motion analyses and century breakdown were utilised in the establishment of a simulated batting protocol. The simulated batting protocol for female batters was created/developed by utilising the method designed by Houghton et al., (2011), who developed the BATEX© protocol. Results: The time-motion analyses indicated that the mean duration of an ODI innings was 169 minutes. An over lasted 2.45 minutes, with 24.86 seconds between each delivery and 55 seconds between each over. When the bowling side changed to a new bowler, it was 1.12 minutes between overs. The mean score for the first power play in an ODI was 41 runs with 1.38 wickets being taken. The mean score during the second power play was 28 runs with 0.714 wickets being taken. The T20 bowling innings lasted 75.50 minutes, with an over lasting 2.52 minutes with 25.58 seconds between deliveries. The mean score in the T20 batting innings was 122 runs. During the power play, which lasted 24.35 minutes, 37 runs were scored with 1.45 wickets being taken. The simulated batting innings was then designed as four stages lasting the duration of a typical women’s century. Each stage was based on theoretical phases of play that may occur during a batting innings. Conclusion: The study indicated that the women’s game has different movement requirements compared to the men’s game in both the ODI and T20 formats. Further, the demands differ depending on the country that is playing. A training and research protocol specifically designed for female batters is an important outcome.
- Full Text:
- Authors: Munro, Catherine
- Date: 2019
- Subjects: Women cricket players , Cricket -- Batting , Cricket -- Coaching , Cricket -- Physiological aspects
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/76342 , vital:30550
- Description: Background: Accurate and reliable in-game data is fundamental when designing effective batting training. A simulated batting protocol that could aid research and training has not been specifically designed for female cricketers because of a distinct lack of empirical in-game data for the women’s version of the game. Objective: The purpose of this study was to quantify the motion demands and run-breakdown of a century and T20 half-century for women’s cricket matches to establish a simulated batting protocol specifically designed for female batters. Method: Time-motion analyses of four one-day international and six T20 innings were conducted on international cricket matches played around the world between 2012 and 2017. The innings was divided into the bowling and batting innings. The ODI innings that met the criterion of 100 runs scored and T20 innings with scores above 50 runs were used in the run breakdown, which included scores from the top 10 countries ranked by the ICC. The time-motion analyses and century breakdown were utilised in the establishment of a simulated batting protocol. The simulated batting protocol for female batters was created/developed by utilising the method designed by Houghton et al., (2011), who developed the BATEX© protocol. Results: The time-motion analyses indicated that the mean duration of an ODI innings was 169 minutes. An over lasted 2.45 minutes, with 24.86 seconds between each delivery and 55 seconds between each over. When the bowling side changed to a new bowler, it was 1.12 minutes between overs. The mean score for the first power play in an ODI was 41 runs with 1.38 wickets being taken. The mean score during the second power play was 28 runs with 0.714 wickets being taken. The T20 bowling innings lasted 75.50 minutes, with an over lasting 2.52 minutes with 25.58 seconds between deliveries. The mean score in the T20 batting innings was 122 runs. During the power play, which lasted 24.35 minutes, 37 runs were scored with 1.45 wickets being taken. The simulated batting innings was then designed as four stages lasting the duration of a typical women’s century. Each stage was based on theoretical phases of play that may occur during a batting innings. Conclusion: The study indicated that the women’s game has different movement requirements compared to the men’s game in both the ODI and T20 formats. Further, the demands differ depending on the country that is playing. A training and research protocol specifically designed for female batters is an important outcome.
- Full Text:
TiRiFiG, a graphical 3D kinematic modelling tool
- Authors: Twum, Samuel Nyarko
- Date: 2019
- Subjects: Tilted Ring Fitting GUI , Astronomy -- Observations , Galaxies -- Observations , Galaxies -- Measurement , Galaxies -- Measurement -- Data processing , Kinematics
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/76409 , vital:30558
- Description: Galaxy kinematics is of crucial importance to understanding the structure, formation and evolution of galaxies. The studies of mass distributions giving rise to the missing mass problem, first raised by Zwicky (1933), give us an insight into dark matter distributions which are tightly linked to cosmology. Neutral hydrogen (H i) has been widely used as a tracer in the kinematic studies of galaxies. The Square Kilometre Array (SKA) and its precursors will produce large Hi datasets which will require kinematic modelling tools to extract kinematic parameters such as rotation curves. TiRiFiC (Józsa et al., 2007) is an example of such a tool for 3D kinematic modelling of resolved spectroscopic observations of rotating disks in terms of the tilted-ring model with varying complexities. TiRiFiC can be used to model a large number (20+) of parameters which are set in a configuration file (.def) for its execution. However, manually editing these parameters in a text editor is uncomfortable. In this work, we present TiRiFiG, Tilted Ring Fitting GUI, which is the graphical user interface that provides an easy way for parameter inputs to be modified in an interactive manner.
- Full Text:
- Authors: Twum, Samuel Nyarko
- Date: 2019
- Subjects: Tilted Ring Fitting GUI , Astronomy -- Observations , Galaxies -- Observations , Galaxies -- Measurement , Galaxies -- Measurement -- Data processing , Kinematics
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/76409 , vital:30558
- Description: Galaxy kinematics is of crucial importance to understanding the structure, formation and evolution of galaxies. The studies of mass distributions giving rise to the missing mass problem, first raised by Zwicky (1933), give us an insight into dark matter distributions which are tightly linked to cosmology. Neutral hydrogen (H i) has been widely used as a tracer in the kinematic studies of galaxies. The Square Kilometre Array (SKA) and its precursors will produce large Hi datasets which will require kinematic modelling tools to extract kinematic parameters such as rotation curves. TiRiFiC (Józsa et al., 2007) is an example of such a tool for 3D kinematic modelling of resolved spectroscopic observations of rotating disks in terms of the tilted-ring model with varying complexities. TiRiFiC can be used to model a large number (20+) of parameters which are set in a configuration file (.def) for its execution. However, manually editing these parameters in a text editor is uncomfortable. In this work, we present TiRiFiG, Tilted Ring Fitting GUI, which is the graphical user interface that provides an easy way for parameter inputs to be modified in an interactive manner.
- Full Text:
Toward universal sustainability: strategies and guidelines
- Authors: Robertson, Struan Ross
- Date: 2019
- Subjects: Sustainability , Sustainable development , Economic development , Social planning
- Language: English
- Type: text , Thesis , Masters , MEcon
- Identifier: http://hdl.handle.net/10962/71591 , vital:29922
- Description: This research considers the notion of universal sustainability, which involves the three well-known pillars of sustainable development, namely, economic development, social development, and environmental sustainability. Critical to achieving this unity of purpose in the aligning of economic and social aspirations with the limits of the natural environment is the enhancing of human capability and the development of political institutions capable of representing the interests of all people by leveraging resources responsibly. Universal sustainability differs from the concept of sustainable development in that the emphasis is cast not on merely achieving economic development despite the challenges presented by social and environmental concerns, but on seeking to understand what a better society might look like that integrates outcomes in-line with these three factors. Universal sustainability is about re-thinking the purpose of material progress to realign this with the need for social cohesion and to reposition human values and expectations safely within ecological boundaries. In other words, strategies and guidelines that promote the realisation of universal sustainability would recommend a society that values economic and technological progress with equal measure to social development and environmental sustainability, as well as all the other factors that promote human wellbeing. Consequently, this research also considers the inter-linkages that are found between economic development (i.e. technological advancement) and social (i.e. normative progress) and societal (i.e. long-term institutional differentiation) development with respect to labour markets, the formation of skills, the scope of welfare regimes and hence, the trajectory of the social reproduction of society. The prospects of environmental sustainability, like that of societal development, are found to be influenced by the values that a society holds and the ability of economic and social factors to adapt in response to the environmental challenges that face societies in socially workable ways. This research concerns the great quest for meaning and purpose that humans have undertaken throughout history, and asks how human wellbeing – in its best, most expansive sense, can be improved and how societies can advance and prosper going forward while keeping the avenue of individual self-actualisation open as a possibility in the everyday lives of citizens? In achieving this end, this research looks at what economic development strategies suggest as tenable against these aspirations. Furthermore, this research looks at the experience of advanced democratic societies to better conceive of how material progress, social cohesion via education and welfare, and environmental sustainability can be attained. The selection of these countries ensures understanding for the kind of political arrangements that safeguard human wellbeing and give voice to freedom, material opportunities, and civic responsibilities. Critical to both these assessments is defining the mechanics that underlie the processes that achieve material and moral progress in human societies. The main goal of this research is to recommend strategies and guidelines for developing countries like South Africa that wish to develop and thrive. Therefore, this research presents an assessment framework for understanding both universal sustainability and how to achieve it. This research concludes that mindfulness about the natural environment and the services it supplies, as well as mindfulness about what drives economic development and what supports the conditions for human flourishing, are necessary for universal sustainability strategies and guidelines to work. Indeed, the ideologies that societies subscribe to and the values they hold are important 84 to creating the right conditions for economic tools to work to advance economic development, material improvement, socio-environmental justice, and ultimately for achieving universal sustainability. But central to both economic and environmental futures is an understanding that at the heart of the matter is a concern for apprehending what drives human behaviour and aspiration, and what creates social cohesion.
- Full Text:
- Authors: Robertson, Struan Ross
- Date: 2019
- Subjects: Sustainability , Sustainable development , Economic development , Social planning
- Language: English
- Type: text , Thesis , Masters , MEcon
- Identifier: http://hdl.handle.net/10962/71591 , vital:29922
- Description: This research considers the notion of universal sustainability, which involves the three well-known pillars of sustainable development, namely, economic development, social development, and environmental sustainability. Critical to achieving this unity of purpose in the aligning of economic and social aspirations with the limits of the natural environment is the enhancing of human capability and the development of political institutions capable of representing the interests of all people by leveraging resources responsibly. Universal sustainability differs from the concept of sustainable development in that the emphasis is cast not on merely achieving economic development despite the challenges presented by social and environmental concerns, but on seeking to understand what a better society might look like that integrates outcomes in-line with these three factors. Universal sustainability is about re-thinking the purpose of material progress to realign this with the need for social cohesion and to reposition human values and expectations safely within ecological boundaries. In other words, strategies and guidelines that promote the realisation of universal sustainability would recommend a society that values economic and technological progress with equal measure to social development and environmental sustainability, as well as all the other factors that promote human wellbeing. Consequently, this research also considers the inter-linkages that are found between economic development (i.e. technological advancement) and social (i.e. normative progress) and societal (i.e. long-term institutional differentiation) development with respect to labour markets, the formation of skills, the scope of welfare regimes and hence, the trajectory of the social reproduction of society. The prospects of environmental sustainability, like that of societal development, are found to be influenced by the values that a society holds and the ability of economic and social factors to adapt in response to the environmental challenges that face societies in socially workable ways. This research concerns the great quest for meaning and purpose that humans have undertaken throughout history, and asks how human wellbeing – in its best, most expansive sense, can be improved and how societies can advance and prosper going forward while keeping the avenue of individual self-actualisation open as a possibility in the everyday lives of citizens? In achieving this end, this research looks at what economic development strategies suggest as tenable against these aspirations. Furthermore, this research looks at the experience of advanced democratic societies to better conceive of how material progress, social cohesion via education and welfare, and environmental sustainability can be attained. The selection of these countries ensures understanding for the kind of political arrangements that safeguard human wellbeing and give voice to freedom, material opportunities, and civic responsibilities. Critical to both these assessments is defining the mechanics that underlie the processes that achieve material and moral progress in human societies. The main goal of this research is to recommend strategies and guidelines for developing countries like South Africa that wish to develop and thrive. Therefore, this research presents an assessment framework for understanding both universal sustainability and how to achieve it. This research concludes that mindfulness about the natural environment and the services it supplies, as well as mindfulness about what drives economic development and what supports the conditions for human flourishing, are necessary for universal sustainability strategies and guidelines to work. Indeed, the ideologies that societies subscribe to and the values they hold are important 84 to creating the right conditions for economic tools to work to advance economic development, material improvement, socio-environmental justice, and ultimately for achieving universal sustainability. But central to both economic and environmental futures is an understanding that at the heart of the matter is a concern for apprehending what drives human behaviour and aspiration, and what creates social cohesion.
- Full Text:
Towards a norm of compliance in recreational fisheries
- Authors: Bova, Christopher S
- Date: 2019
- Subjects: Fishing -- Management -- South Africa , Fishery law and legislation -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/95909 , vital:31213
- Description: The activity of fishing can be traced back to prehistoric times. However, only in the last century has there been a focus on the management of fisheries. Fishery regulations are tools used by resource managers with the aim of protecting the long-term sustainability of fishery resources. Although there is an overwhelming amount of evidence demonstrating the decline of fisheries, non-compliance with these regulations by fishers continues to manifest, which can exacerbate the negative ecological impacts of fisheries. Popular methods towards the measurement of noncompliance in fisheries derived from previous human dimensions literature may be flawed. Theories on improving compliance behaviour have typically relied on theory, which has at times proved paradoxical. Addressing the issues of non-compliance within a fishery of interest requires measuring the levels of non-compliance within the fishery and determining the relevant sociopsychological drivers behind the non-compliant behaviour. The data collection methods used during these assessments are limited in human dimensions research and are often case and context specific, requiring researchers to identify which approach is most practical for the specific fishery of interest. By identifying relevant behavioural drivers of non-compliance, a more effective approach aimed at improving compliance can be tailored. The recreational marine-based shore fishery (MBSF) in South Africa is not impervious to noncomplaint behaviour. In fact, it has been estimated to have relatively high rates of non-compliance. This high level of non-compliance makes the South African MBSF a unique and optimal context in which to undertake research that aims to formulate a framework towards compliance assessments and that develops a suitable approach for improving compliance rates. Using surveys to obtain compliance data can provide a range of details about violators, however they are susceptible to social desirability bias (SDB). Choosing the best method for controlling SDB required an assessment of existing methods for doing so. In this first part of the study, only fishers who were covertly observed breaking the rules were surveyed, using one of three methods for reducing SDB, to ground-truth the responses. Ground-truthing was done to determine which method would be most effective for a large-scale study within the same fishery. Of the methods used, which include the direct questioning method (DQM), the random response technique (RRT) and the ballot box method (BBM), all contained some level of SDB. However, the BBM provided a significantly higher level of response accuracy (79.6% ± 11.9) than the DQM (46.5% ± 14.9) and the RRT (44.3% ± 12.5). Random-stratified roving creel compliance surveys that employed the BBM were then undertaken at various locations along South Africa’s coastline to estimate current rates of non-compliance, and the face-to-face results were compared to results from an identical online survey to determine the suitability of online surveys as a replacement. The results indicated that online surveys only represent a subgroup of the fisher population within the MBSF, suggesting that face-to-face survey methods are required to obtain a more comprehensive sample and a more robust estimate of noncompliance. The results, based on 453 face-to-face surveys, showed a high level of overall self-reported noncompliance (48.3%) within the fishery. Responses to Likert scale survey questions on various aspects of the fishery, including angler motivations for fishing, were then modelled to test the relationship between the anglers’ responses and their compliance behaviour. In the South African MBSF context, the most significant behavioural drivers behind non-compliance related to normative concepts. Specifically, the poor perceptions of management and value-based legitimacy as well as low levels of moral obligation to adhere to the regulations appeared to contribute most to the observed non-compliant behaviour. Angler motivations for fishing also played a significant role in determining the compliance behaviour of anglers, with those fishing for food being more likely to violate regulations. In most countries, regardless of economic context, interventions to improve recreational fishery compliance have been developed around the instrumental concept. However, these findings suggest that for recreational fisheries, managers would do well to evaluate the impact of normative concepts on compliance and to design interventions aimed at addressing these. In the case of the South African MBSF, interventions that address angler perceptions of legitimacy and aim to correct misperceptions about social norms of compliance may provide a more practical and cost- effective method for improving poor compliance behaviour.
- Full Text:
- Authors: Bova, Christopher S
- Date: 2019
- Subjects: Fishing -- Management -- South Africa , Fishery law and legislation -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/95909 , vital:31213
- Description: The activity of fishing can be traced back to prehistoric times. However, only in the last century has there been a focus on the management of fisheries. Fishery regulations are tools used by resource managers with the aim of protecting the long-term sustainability of fishery resources. Although there is an overwhelming amount of evidence demonstrating the decline of fisheries, non-compliance with these regulations by fishers continues to manifest, which can exacerbate the negative ecological impacts of fisheries. Popular methods towards the measurement of noncompliance in fisheries derived from previous human dimensions literature may be flawed. Theories on improving compliance behaviour have typically relied on theory, which has at times proved paradoxical. Addressing the issues of non-compliance within a fishery of interest requires measuring the levels of non-compliance within the fishery and determining the relevant sociopsychological drivers behind the non-compliant behaviour. The data collection methods used during these assessments are limited in human dimensions research and are often case and context specific, requiring researchers to identify which approach is most practical for the specific fishery of interest. By identifying relevant behavioural drivers of non-compliance, a more effective approach aimed at improving compliance can be tailored. The recreational marine-based shore fishery (MBSF) in South Africa is not impervious to noncomplaint behaviour. In fact, it has been estimated to have relatively high rates of non-compliance. This high level of non-compliance makes the South African MBSF a unique and optimal context in which to undertake research that aims to formulate a framework towards compliance assessments and that develops a suitable approach for improving compliance rates. Using surveys to obtain compliance data can provide a range of details about violators, however they are susceptible to social desirability bias (SDB). Choosing the best method for controlling SDB required an assessment of existing methods for doing so. In this first part of the study, only fishers who were covertly observed breaking the rules were surveyed, using one of three methods for reducing SDB, to ground-truth the responses. Ground-truthing was done to determine which method would be most effective for a large-scale study within the same fishery. Of the methods used, which include the direct questioning method (DQM), the random response technique (RRT) and the ballot box method (BBM), all contained some level of SDB. However, the BBM provided a significantly higher level of response accuracy (79.6% ± 11.9) than the DQM (46.5% ± 14.9) and the RRT (44.3% ± 12.5). Random-stratified roving creel compliance surveys that employed the BBM were then undertaken at various locations along South Africa’s coastline to estimate current rates of non-compliance, and the face-to-face results were compared to results from an identical online survey to determine the suitability of online surveys as a replacement. The results indicated that online surveys only represent a subgroup of the fisher population within the MBSF, suggesting that face-to-face survey methods are required to obtain a more comprehensive sample and a more robust estimate of noncompliance. The results, based on 453 face-to-face surveys, showed a high level of overall self-reported noncompliance (48.3%) within the fishery. Responses to Likert scale survey questions on various aspects of the fishery, including angler motivations for fishing, were then modelled to test the relationship between the anglers’ responses and their compliance behaviour. In the South African MBSF context, the most significant behavioural drivers behind non-compliance related to normative concepts. Specifically, the poor perceptions of management and value-based legitimacy as well as low levels of moral obligation to adhere to the regulations appeared to contribute most to the observed non-compliant behaviour. Angler motivations for fishing also played a significant role in determining the compliance behaviour of anglers, with those fishing for food being more likely to violate regulations. In most countries, regardless of economic context, interventions to improve recreational fishery compliance have been developed around the instrumental concept. However, these findings suggest that for recreational fisheries, managers would do well to evaluate the impact of normative concepts on compliance and to design interventions aimed at addressing these. In the case of the South African MBSF, interventions that address angler perceptions of legitimacy and aim to correct misperceptions about social norms of compliance may provide a more practical and cost- effective method for improving poor compliance behaviour.
- Full Text:
Towards defining the tipping point of tolerance to CO2-induced ocean acidification for the growth, development and metabolism of larval dusky kob Argyrosomus japonicus (Pisces: Sciaenidae)
- Authors: Mpopetsi, Pule Peter
- Date: 2019
- Subjects: Argyrosomus japonicus , Argyrosomus , Argyrosomus japonicus -- Larvae , Argyrosomus -- Larvae -- Effect of water acidification on , Argyrosomus japonicus -- Larvae -- Nutrition , Argyrosomus -- Larvae -- Nutrition , Ocean acidification
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/71602 , vital:29924
- Description: Increased CO2 production and the consequent ocean acidification (OA) have been identified as one of the greatest threats to both calcifying and non-calcifying marine organisms. Traditionally, marine fishes, as non-calcifying organisms, were considered to have a higher tolerance to near-future OA conditions owing to their well-developed ion regulatory mechanisms. However, recent studies provide evidence to suggest that they may not be as resilient to near-future OA conditions as previously thought. In addition, earlier life stages of marine fishes are thought to be less tolerant than juveniles and adults of the same species as they lack well-developed ion regulatory mechanisms for maintaining homeostasis. This study follows up on previous studies examining the effects of near-future OA on larval Argyrosomus japonicus, an estuarine-dependent marine fish species, in order to identify the tipping point of tolerance for the larvae of this species. These previous studies showed that elevated pCO2, predicted for the year 2100, had negative effects on growth, development and metabolism and ultimately, survival of larval A. japonicus from post-flexion stage. Larval A. japonicus in the present study were reared from egg up to 22 DAH (days after hatching) under three treatments. The three treatments, (pCO2 353 μatm; pH 8.03), (pCO2 451 μatm; pH 7.93) and (pCO2 602 μatm; pH 7.83) corresponded to levels predicted to occur in year 2050, 2068 and 2090 respectively under the Intergovernmental Panel on Climate Change (IPCC) Representative Concentration Pathways (IPCC RCP) 8.5 model. Size-at-hatch, growth, development and metabolic responses (standard and active metabolic rates and metabolic scope) were assessed and compared between the three treatments throughout the rearing period. Five earlier larval life stages (hatchling – flexion/post-flexion) were identified by the end of the experiment. There were no significant differences in size-at-hatch (P > 0.05), development or the active metabolic (P > 0.05) or metabolic scope (P > 0.05) of fish in the three treatments throughout the study. However, the standard metabolic rate was significantly higher in the year 2068 treatment but only at the flexion/post-flexion stage which could be attributed to differences in developmental rates (including the development of the gills) between the 2068 and the other two treatments. Overall, the metabolic scope was narrowest in the 2090 treatment, but varied according to life stage. Although not significantly different, metabolic scope in the 2090 treatment was noticeably lower at the flexion stage compared to the other two treatments, and the development appeared slower, suggesting that this could be the stage most prone to OA. The study concluded that, in isolation, OA levels predicted to occur between 2050 and 2090 will not negatively affect size-at-hatch, growth, development, and metabolic responses of larval A. japonicus up to 22 DAH (flexion/post-flexion stage). Taken together with the previous studies of the same species, the tipping point of tolerance (where negative impacts will begin) in larvae of the species appears to be between the years 2090 and 2100.
- Full Text:
- Authors: Mpopetsi, Pule Peter
- Date: 2019
- Subjects: Argyrosomus japonicus , Argyrosomus , Argyrosomus japonicus -- Larvae , Argyrosomus -- Larvae -- Effect of water acidification on , Argyrosomus japonicus -- Larvae -- Nutrition , Argyrosomus -- Larvae -- Nutrition , Ocean acidification
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/71602 , vital:29924
- Description: Increased CO2 production and the consequent ocean acidification (OA) have been identified as one of the greatest threats to both calcifying and non-calcifying marine organisms. Traditionally, marine fishes, as non-calcifying organisms, were considered to have a higher tolerance to near-future OA conditions owing to their well-developed ion regulatory mechanisms. However, recent studies provide evidence to suggest that they may not be as resilient to near-future OA conditions as previously thought. In addition, earlier life stages of marine fishes are thought to be less tolerant than juveniles and adults of the same species as they lack well-developed ion regulatory mechanisms for maintaining homeostasis. This study follows up on previous studies examining the effects of near-future OA on larval Argyrosomus japonicus, an estuarine-dependent marine fish species, in order to identify the tipping point of tolerance for the larvae of this species. These previous studies showed that elevated pCO2, predicted for the year 2100, had negative effects on growth, development and metabolism and ultimately, survival of larval A. japonicus from post-flexion stage. Larval A. japonicus in the present study were reared from egg up to 22 DAH (days after hatching) under three treatments. The three treatments, (pCO2 353 μatm; pH 8.03), (pCO2 451 μatm; pH 7.93) and (pCO2 602 μatm; pH 7.83) corresponded to levels predicted to occur in year 2050, 2068 and 2090 respectively under the Intergovernmental Panel on Climate Change (IPCC) Representative Concentration Pathways (IPCC RCP) 8.5 model. Size-at-hatch, growth, development and metabolic responses (standard and active metabolic rates and metabolic scope) were assessed and compared between the three treatments throughout the rearing period. Five earlier larval life stages (hatchling – flexion/post-flexion) were identified by the end of the experiment. There were no significant differences in size-at-hatch (P > 0.05), development or the active metabolic (P > 0.05) or metabolic scope (P > 0.05) of fish in the three treatments throughout the study. However, the standard metabolic rate was significantly higher in the year 2068 treatment but only at the flexion/post-flexion stage which could be attributed to differences in developmental rates (including the development of the gills) between the 2068 and the other two treatments. Overall, the metabolic scope was narrowest in the 2090 treatment, but varied according to life stage. Although not significantly different, metabolic scope in the 2090 treatment was noticeably lower at the flexion stage compared to the other two treatments, and the development appeared slower, suggesting that this could be the stage most prone to OA. The study concluded that, in isolation, OA levels predicted to occur between 2050 and 2090 will not negatively affect size-at-hatch, growth, development, and metabolic responses of larval A. japonicus up to 22 DAH (flexion/post-flexion stage). Taken together with the previous studies of the same species, the tipping point of tolerance (where negative impacts will begin) in larvae of the species appears to be between the years 2090 and 2100.
- Full Text:
Towards understanding and mitigating attacks leveraging zero-day exploits
- Authors: Smit, Liam
- Date: 2019
- Subjects: Computer crimes -- Prevention , Data protection , Hacking , Computer security , Computer networks -- Security measures , Computers -- Access control , Malware (Computer software)
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/115718 , vital:34218
- Description: Zero-day vulnerabilities are unknown and therefore not addressed with the result that they can be exploited by attackers to gain unauthorised system access. In order to understand and mitigate against attacks leveraging zero-days or unknown techniques, it is necessary to study the vulnerabilities, exploits and attacks that make use of them. In recent years there have been a number of leaks publishing such attacks using various methods to exploit vulnerabilities. This research seeks to understand what types of vulnerabilities exist, why and how these are exploited, and how to defend against such attacks by either mitigating the vulnerabilities or the method / process of exploiting them. By moving beyond merely remedying the vulnerabilities to defences that are able to prevent or detect the actions taken by attackers, the security of the information system will be better positioned to deal with future unknown threats. An interesting finding is how attackers exploit moving beyond the observable bounds to circumvent security defences, for example, compromising syslog servers, or going down to lower system rings to gain access. However, defenders can counter this by employing defences that are external to the system preventing attackers from disabling them or removing collected evidence after gaining system access. Attackers are able to defeat air-gaps via the leakage of electromagnetic radiation as well as misdirect attribution by planting false artefacts for forensic analysis and attacking from third party information systems. They analyse the methods of other attackers to learn new techniques. An example of this is the Umbrage project whereby malware is analysed to decide whether it should be implemented as a proof of concept. Another important finding is that attackers respect defence mechanisms such as: remote syslog (e.g. firewall), core dump files, database auditing, and Tripwire (e.g. SlyHeretic). These defences all have the potential to result in the attacker being discovered. Attackers must either negate the defence mechanism or find unprotected targets. Defenders can use technologies such as encryption to defend against interception and man-in-the-middle attacks. They can also employ honeytokens and honeypots to alarm misdirect, slow down and learn from attackers. By employing various tactics defenders are able to increase their chance of detecting and time to react to attacks, even those exploiting hitherto unknown vulnerabilities. To summarize the information presented in this thesis and to show the practical importance thereof, an examination is presented of the NSA's network intrusion of the SWIFT organisation. It shows that the firewalls were exploited with remote code execution zerodays. This attack has a striking parallel in the approach used in the recent VPNFilter malware. If nothing else, the leaks provide information to other actors on how to attack and what to avoid. However, by studying state actors, we can gain insight into what other actors with fewer resources can do in the future.
- Full Text:
- Authors: Smit, Liam
- Date: 2019
- Subjects: Computer crimes -- Prevention , Data protection , Hacking , Computer security , Computer networks -- Security measures , Computers -- Access control , Malware (Computer software)
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/115718 , vital:34218
- Description: Zero-day vulnerabilities are unknown and therefore not addressed with the result that they can be exploited by attackers to gain unauthorised system access. In order to understand and mitigate against attacks leveraging zero-days or unknown techniques, it is necessary to study the vulnerabilities, exploits and attacks that make use of them. In recent years there have been a number of leaks publishing such attacks using various methods to exploit vulnerabilities. This research seeks to understand what types of vulnerabilities exist, why and how these are exploited, and how to defend against such attacks by either mitigating the vulnerabilities or the method / process of exploiting them. By moving beyond merely remedying the vulnerabilities to defences that are able to prevent or detect the actions taken by attackers, the security of the information system will be better positioned to deal with future unknown threats. An interesting finding is how attackers exploit moving beyond the observable bounds to circumvent security defences, for example, compromising syslog servers, or going down to lower system rings to gain access. However, defenders can counter this by employing defences that are external to the system preventing attackers from disabling them or removing collected evidence after gaining system access. Attackers are able to defeat air-gaps via the leakage of electromagnetic radiation as well as misdirect attribution by planting false artefacts for forensic analysis and attacking from third party information systems. They analyse the methods of other attackers to learn new techniques. An example of this is the Umbrage project whereby malware is analysed to decide whether it should be implemented as a proof of concept. Another important finding is that attackers respect defence mechanisms such as: remote syslog (e.g. firewall), core dump files, database auditing, and Tripwire (e.g. SlyHeretic). These defences all have the potential to result in the attacker being discovered. Attackers must either negate the defence mechanism or find unprotected targets. Defenders can use technologies such as encryption to defend against interception and man-in-the-middle attacks. They can also employ honeytokens and honeypots to alarm misdirect, slow down and learn from attackers. By employing various tactics defenders are able to increase their chance of detecting and time to react to attacks, even those exploiting hitherto unknown vulnerabilities. To summarize the information presented in this thesis and to show the practical importance thereof, an examination is presented of the NSA's network intrusion of the SWIFT organisation. It shows that the firewalls were exploited with remote code execution zerodays. This attack has a striking parallel in the approach used in the recent VPNFilter malware. If nothing else, the leaks provide information to other actors on how to attack and what to avoid. However, by studying state actors, we can gain insight into what other actors with fewer resources can do in the future.
- Full Text:
Training intervention for volunteers supporting victims of intimate partner violence in South Africa
- Authors: Thomas, Samantha
- Date: 2019
- Subjects: Intimate partner violence -- Psychological aspects , Victims of family violence -- Services for -- South Africa , Marital violence , Victims of dating violence , Family violence -- Law and legislation , Non-governmental organizations -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/65079 , vital:28679
- Description: Intimate Partner Violence continues to be a significant social problem in South Africa, requiring a systematised and effective response at multiple levels. The organisation at the centre of this research offers crisis intervention to victims of intimate partner violence, providing basic psychological support, legal information and referrals. The volunteer crisis interventionists are exposed to numerous in-depth accounts of violent and distressing victimisation, making them more vulnerable to vicarious traumatisation. Through this work, their prior assumptions about personal safety, the trustworthiness of other people, and basic justice in the world, are challenged. The challenge to these assumptions increases the likelihood of countertransference victim blaming responses, as it is often easier to hold the client responsible for the tragic event than for the support worker to transform their own assumptions about safety and justice. This victim blaming response is supported by the dominant patriarchal ideology which frequently seeks to maintain the systems of oppression, excusing the perpetrator and placing responsibility on the victim. It was therefore clear that in order to do this work effectively, volunteers needed to be trained to identify their countertransference reactions and emotional responses, as well as undergo a critical re-assessment of their ideas relating to intimate partner violence and victimisation. Using an Intervention Research paradigm, this research designed and developed a training programme based on transformative learning theory, moving away from traditional information models of training to a focus on emotional skills and critical self-insight. The phases of the intervention refined the intervention in order to ensure that the research objectives were met and that the programme could be easily replicated. The evaluation of each phase showed an increased capacity for critical insight, and evidence for a transformative shift in the trainees understanding and approach to intimate partner violence.
- Full Text:
Training intervention for volunteers supporting victims of intimate partner violence in South Africa
- Authors: Thomas, Samantha
- Date: 2019
- Subjects: Intimate partner violence -- Psychological aspects , Victims of family violence -- Services for -- South Africa , Marital violence , Victims of dating violence , Family violence -- Law and legislation , Non-governmental organizations -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/65079 , vital:28679
- Description: Intimate Partner Violence continues to be a significant social problem in South Africa, requiring a systematised and effective response at multiple levels. The organisation at the centre of this research offers crisis intervention to victims of intimate partner violence, providing basic psychological support, legal information and referrals. The volunteer crisis interventionists are exposed to numerous in-depth accounts of violent and distressing victimisation, making them more vulnerable to vicarious traumatisation. Through this work, their prior assumptions about personal safety, the trustworthiness of other people, and basic justice in the world, are challenged. The challenge to these assumptions increases the likelihood of countertransference victim blaming responses, as it is often easier to hold the client responsible for the tragic event than for the support worker to transform their own assumptions about safety and justice. This victim blaming response is supported by the dominant patriarchal ideology which frequently seeks to maintain the systems of oppression, excusing the perpetrator and placing responsibility on the victim. It was therefore clear that in order to do this work effectively, volunteers needed to be trained to identify their countertransference reactions and emotional responses, as well as undergo a critical re-assessment of their ideas relating to intimate partner violence and victimisation. Using an Intervention Research paradigm, this research designed and developed a training programme based on transformative learning theory, moving away from traditional information models of training to a focus on emotional skills and critical self-insight. The phases of the intervention refined the intervention in order to ensure that the research objectives were met and that the programme could be easily replicated. The evaluation of each phase showed an increased capacity for critical insight, and evidence for a transformative shift in the trainees understanding and approach to intimate partner violence.
- Full Text:
Truth and reconciliation and other stories: a critical multimodal investigation of representations of post-apartheid South Africa in children's picturebooks: volume 1
- Authors: Smith, Jade
- Date: 2019
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/97614 , vital:31458
- Description: Expected release date-April 2021
- Full Text: false
- Authors: Smith, Jade
- Date: 2019
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/97614 , vital:31458
- Description: Expected release date-April 2021
- Full Text: false
Understanding defiant identities: an ethnography of gays and lesbians in Harare, Zimbabwe
- Authors: Muparamoto, Nelson
- Date: 2019
- Subjects: Gays -- Zimbabwe , Gays -- Abuse of -- Zimbabwe , Homosexuality -- Zimbabwe , Homosexuality -- Political aspects -- Zimbabwe , Homosexuality -- Social aspects -- Zimbabwe , Homosexuality -- Religious aspects -- Zimbabwe , Homophobia -- Zimbabwe
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/67720 , vital:29133
- Description: Over the years, western and local media have mediated a narrative of a thoroughly homophobic Zimbabwe, not the least emanating from the former president Robert Mugabe’s ongoing homocritical utterances which recurrently generated global news stories. The country does indeed have a protracted history characterised by various forms of attacks on Gays and Lesbians of Zimbabwe, its membership, and the general lesbian, gay, bisexual, and transgender (LGBT) community. A dominant discourse has framed homosexual identities as on or beyond the border of what is acceptable, giving the clear message that they should not be tolerated. However, the narrative needs a more nuanced analysis than what has been popularised. That homophobia has played a significant role in Zimbabwe is of great import, but it is not and cannot be all there is to say about LGBT lives in the country. And, while scholarship on Zimbabwean homosexualities has engaged with debates about its indigeneity, morality and acceptability, it has as of yet not significantly explored the lived realities of non-heterosexual individuals from their own point of view. This thesis aims to begin doing exactly that, addressing the experiences of same-sex loving and attracted individuals in Harare. Drawing on ethnographic sociology, the thesis focuses on understanding how gay and lesbian identities are constructed, negotiated and experienced within an environment that is in many ways overtly homophobic, where, for example, the risk for social exclusion is considerable. It explores what characterises and shapes gay and lesbian identities in Harare in an attempt to interrogate how they reinforce, modify and challenge dominant social categories and relate to globally circulating queer identity categories. The thesis demonstrates that the construction of identities among same sex loving people in Harare variously draws on both locally and globally circulating ideas and insights. The thesis reveals that beyond the considerable attacks on homosexual identities in Zimbabwe, the intersection of local and international discourses on gay and lesbian identities produces identities that are to varying degrees emergent, fluid and perhaps fragmented. Despite attempts to expunge non-heterosexuals from Zimbabwean citizenry by drawing borders on the basis of sexual orientation, same sex loving individuals in Harare have defiantly expressed, negotiated and managed their sexual identities. The thesis describes and analyses things like dating patterns, decision making in same sex relations as well as family and religious experiences. Invoking Goffman’s concept of self-presentation enables one to understand how participants expressed themselves in the midst of like-minded or homo-tolerant individuals and how they deployed themselves in ‘spaces’ considered homocritical or where resentment was likely to be provoked by them openly expressing their sexual orientation. Crucially, same-sex loving and attracted individuals are agentic individuals who have variously stretched the traditional meanings associated with gender and sexuality in a context characterised by heteronormativity. This thesis usefully deploys Giddens’ (1991, 1992) theorisation of late modernity as characterised by conditions allowing a profusion of competing and sometimes contradictory identity discourses which offers the opportunity for self-reflexivity and identity negotiation. This helps us to understand the defiant identities. Whereas western circulating identity politics tout ‘coming out of the closet’, for most of the participants overt indiscriminate disclosure was to be avoided with participants therein deploying strategies that would help them to remain closeted to some family members as well as in religious circles. The consequences of ‘outing’ or disclosure are ostensibly not straightforward but complex, thus requiring a nuanced analysis that goes beyond the binary categories framed as either negative or positive. The thesis shows that experiences of same sex loving people in their families are complex rather than simply situated on the polar ends of either rejection or acceptance. Whilst dominant discourse has depicted religion as fuelling homophobia as it depicts a Christian identity and queer identities as incompatible, the thesis also explores how some participants challenge the borders drawn in religious circles and maintain a relatively active religious life but not always without conflict.
- Full Text:
- Authors: Muparamoto, Nelson
- Date: 2019
- Subjects: Gays -- Zimbabwe , Gays -- Abuse of -- Zimbabwe , Homosexuality -- Zimbabwe , Homosexuality -- Political aspects -- Zimbabwe , Homosexuality -- Social aspects -- Zimbabwe , Homosexuality -- Religious aspects -- Zimbabwe , Homophobia -- Zimbabwe
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/67720 , vital:29133
- Description: Over the years, western and local media have mediated a narrative of a thoroughly homophobic Zimbabwe, not the least emanating from the former president Robert Mugabe’s ongoing homocritical utterances which recurrently generated global news stories. The country does indeed have a protracted history characterised by various forms of attacks on Gays and Lesbians of Zimbabwe, its membership, and the general lesbian, gay, bisexual, and transgender (LGBT) community. A dominant discourse has framed homosexual identities as on or beyond the border of what is acceptable, giving the clear message that they should not be tolerated. However, the narrative needs a more nuanced analysis than what has been popularised. That homophobia has played a significant role in Zimbabwe is of great import, but it is not and cannot be all there is to say about LGBT lives in the country. And, while scholarship on Zimbabwean homosexualities has engaged with debates about its indigeneity, morality and acceptability, it has as of yet not significantly explored the lived realities of non-heterosexual individuals from their own point of view. This thesis aims to begin doing exactly that, addressing the experiences of same-sex loving and attracted individuals in Harare. Drawing on ethnographic sociology, the thesis focuses on understanding how gay and lesbian identities are constructed, negotiated and experienced within an environment that is in many ways overtly homophobic, where, for example, the risk for social exclusion is considerable. It explores what characterises and shapes gay and lesbian identities in Harare in an attempt to interrogate how they reinforce, modify and challenge dominant social categories and relate to globally circulating queer identity categories. The thesis demonstrates that the construction of identities among same sex loving people in Harare variously draws on both locally and globally circulating ideas and insights. The thesis reveals that beyond the considerable attacks on homosexual identities in Zimbabwe, the intersection of local and international discourses on gay and lesbian identities produces identities that are to varying degrees emergent, fluid and perhaps fragmented. Despite attempts to expunge non-heterosexuals from Zimbabwean citizenry by drawing borders on the basis of sexual orientation, same sex loving individuals in Harare have defiantly expressed, negotiated and managed their sexual identities. The thesis describes and analyses things like dating patterns, decision making in same sex relations as well as family and religious experiences. Invoking Goffman’s concept of self-presentation enables one to understand how participants expressed themselves in the midst of like-minded or homo-tolerant individuals and how they deployed themselves in ‘spaces’ considered homocritical or where resentment was likely to be provoked by them openly expressing their sexual orientation. Crucially, same-sex loving and attracted individuals are agentic individuals who have variously stretched the traditional meanings associated with gender and sexuality in a context characterised by heteronormativity. This thesis usefully deploys Giddens’ (1991, 1992) theorisation of late modernity as characterised by conditions allowing a profusion of competing and sometimes contradictory identity discourses which offers the opportunity for self-reflexivity and identity negotiation. This helps us to understand the defiant identities. Whereas western circulating identity politics tout ‘coming out of the closet’, for most of the participants overt indiscriminate disclosure was to be avoided with participants therein deploying strategies that would help them to remain closeted to some family members as well as in religious circles. The consequences of ‘outing’ or disclosure are ostensibly not straightforward but complex, thus requiring a nuanced analysis that goes beyond the binary categories framed as either negative or positive. The thesis shows that experiences of same sex loving people in their families are complex rather than simply situated on the polar ends of either rejection or acceptance. Whilst dominant discourse has depicted religion as fuelling homophobia as it depicts a Christian identity and queer identities as incompatible, the thesis also explores how some participants challenge the borders drawn in religious circles and maintain a relatively active religious life but not always without conflict.
- Full Text:
Understanding the experiences of Zimbabwean students as foreign students at South African universities: the case of Rhodes University
- Authors: Daki, Andile Lebohang
- Date: 2019
- Subjects: Rhodes University -- Students -- Attitudes , Zimbabwean college students -- South Africa , Zimbabwean college students -- South Africa -- Conduct of life , Zimbabwean college students -- South Africa -- Psychology
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/96225 , vital:31252
- Description: This thesis seeks to understand the cultural and social experiences of black Zimbabwean students, as foreign students, at Rhodes University in Grahamstown, South Africa. It examines the ways in which black Zimbabwean students negotiate the cultural, social and institutional milieu of Rhodes University, which is a former white English-medium university. In doing so, the thesis draws upon Interface theory because, once entering the university space, these students interpret the space and simultaneously negotiate their way in and through this space along cultural and social interfaces. The fieldwork for the thesis involved in-depth interviews with eighteen black Zimbabwean students at the university, stratified in terms of both gender and year of study. A focus on gender facilitated an understanding of possible differences between male and female Zimbabwean students in terms of social and cultural experiences; while a consideration of year of study allowed for an examination of possible shifts in negotiation over time, from first year to Master’s level. The findings demonstrate a range of challenges faced by black Zimbabwean students while at Rhodes University, some of which arise from differences between Zimbabwean and South African society. At the same time, there are considerable differences amongst black Zimbabwean students in relation to the manner in which negotiation took place. While some students negotiate the space through active socialising and assimilating into the local world and lives of South African students as well as the university’s institutional culture, other students negotiate the space through isolation and alienation. Overall, with regard to adjusting to the world of Rhodes and South Africa, students pursued different routes which, in the end, made sense to them.
- Full Text:
- Authors: Daki, Andile Lebohang
- Date: 2019
- Subjects: Rhodes University -- Students -- Attitudes , Zimbabwean college students -- South Africa , Zimbabwean college students -- South Africa -- Conduct of life , Zimbabwean college students -- South Africa -- Psychology
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/96225 , vital:31252
- Description: This thesis seeks to understand the cultural and social experiences of black Zimbabwean students, as foreign students, at Rhodes University in Grahamstown, South Africa. It examines the ways in which black Zimbabwean students negotiate the cultural, social and institutional milieu of Rhodes University, which is a former white English-medium university. In doing so, the thesis draws upon Interface theory because, once entering the university space, these students interpret the space and simultaneously negotiate their way in and through this space along cultural and social interfaces. The fieldwork for the thesis involved in-depth interviews with eighteen black Zimbabwean students at the university, stratified in terms of both gender and year of study. A focus on gender facilitated an understanding of possible differences between male and female Zimbabwean students in terms of social and cultural experiences; while a consideration of year of study allowed for an examination of possible shifts in negotiation over time, from first year to Master’s level. The findings demonstrate a range of challenges faced by black Zimbabwean students while at Rhodes University, some of which arise from differences between Zimbabwean and South African society. At the same time, there are considerable differences amongst black Zimbabwean students in relation to the manner in which negotiation took place. While some students negotiate the space through active socialising and assimilating into the local world and lives of South African students as well as the university’s institutional culture, other students negotiate the space through isolation and alienation. Overall, with regard to adjusting to the world of Rhodes and South Africa, students pursued different routes which, in the end, made sense to them.
- Full Text:
Understanding the learning that occurs through up-skilling opportunities and practices in the marine sector of South Africa
- Authors: Bell, Caroline Margaret
- Date: 2019
- Subjects: Biodiversity conservation -- South Africa , Human capital -- South Africa , Marine sciences -- Employees -- South Africa -- Training of , Biodiversity Human Capital Development Strategy (South Africa)
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/93966 , vital:30977
- Description: South Africa is characterised by cultural and biological diversity which constitute a unique context in which to conduct educational research, such as this doctoral study looking at human capital development in the marine biodiversity context. The drive for transformation in the country is also a major factor to consider when researching any sector of the economy, in this case, the biodiversity sector. The biodiversity sector includes organisations involved in biodiversity conservation, research and management. Previous research in the sector has found a clear need for well-thought out workplace skills plans within conservation and research organisations. The national Biodiversity Human Capital Development Strategy that was produced in 2010 by the South African National Biodiversity Institute outlines how all the organisations involved in the biodiversity sector of South Africa need to participate in strengthening the sector through a range of human capital development strategies. This includes extending the existing human capacity of managers and scientists who are already in the workplace, i.e. up-skilling. In particular, ‘scarce’ skills, as identified by the national Environmental Sector Skills Plan need further attention and development. The scarce skills relevant to this study are: protected area managers; ecosystem managers and post-graduate researchers, hence the focus on managers and scientists in this research. The marine sector falls within the biodiversity sector and it faces multiple conservation challenges which are complex and it is therefore essential to have skilled and capable managers and scientists in place. By investigating the up-skilling opportunities and practices available to these marine professionals, the goal is to understand if and how learning takes place in the marine sector of South Africa. The main research question of this study is: How do up-skilling opportunities and practices enable learning in, through and for the workplace, by marine professionals? In addition, three sub-questions provide finer details and introduce the central concepts of the research: I. What up-skilling opportunities and professional practices exist in or for, marine research and conservation organisations and how are they constituted and enacted via practice-based sayings, doings and relatings? II. How do the individuals learn and exercise their agency within the socio-material realities of the marine scientific and management context, through making use of up-skilling opportunities that are both formal (e.g. course based) and informal? III. How do generative mechanisms shape the constitution and enactment of up-skilling opportunities and practices, and the learning and agency of marine professionals (scientists and managers)? The theoretical work of this study consisted of, first, considering sensitising concepts which included: defining skill and knowledge; considering what an up-skilling opportunity might look like; workplace learning (both formal and informal learning); professional practices, lifelong learning or adult education, and agency in the workplace. Critical realism was then employed as the meta-theory that underlabours this research, while the substantive theories used for analysis purposes were socio-materialism and practice theory. Of course, critical realism is a socio-material theory itself, and Bhaskar’s four-planar social being or Social Cube was used to interpret and synthesise the findings in the data chapters. The methodological framework of this study explores the implications of critical realism for research design and analysis and includes a contextual profiling phase, semi-structured interviews, analysis of documents and peer-reviewed papers, as well as observations. There are nine case studies that form the focus of this research and in total 18 research participants were involved. Data analysis included abduction and retroduction as the primary modes of inference and the main analytical tool was the framework of practice architectures where I took the ‘sayings’, ‘doings’ and ‘relatings’ as themes. Further themes were developed from the other relevant theories used in this study; hence socio-materialism, learning, agency, and formal and informal opportunities, were also used as themes when coding the data. Issues around validity, ethics and reflexivity are key elements of the research design and were carefully considered throughout the research process. The principal data chapters are structured in such a way that each sub-question is considered and ultimately the findings are presented in the form of generative mechanisms which included: the politics of social transformation and knowledge as a driving force of up-skilling; the influence of individual disposition and passion or will; the importance of the socio-material realities and realistic expectations; and how relationality is critical for the marine sector. Agency was a cross-cutting theme in all the discussions around learning, practices and the role of the material, and was highly influential on the mechanisms that have been described in this study. The experiences, events and mechanisms that were uncovered in this research provide insight into the forms of learning as these relate to up-skilling that occur in the marine sector, as well as the complex relationships between formal and informal learning. The professional practices that occur in the everyday working lives of the marine professionals were shown to be an integral part of the learning process, while formal, certified opportunities are important for strengthening the field and building conservation competence in the country. By uncovering the deeper structures and mechanisms that have power and causal efficacy when it comes to up-skilling opportunities, learning and professional practices, this study has contributed to the field of environmental education as it shows how up-skilling processes operate in complex formations that involve formal and informal learning processes in workplaces. The study also offers a more nuanced view of the relational objects in this field, such as up-skilling and workplace learning, via the inclusion of a socio-material analysis. Through a theoretical and methodological framework that focused on the material using the tools of practice theory and Bhaskar’s depth ontology and four-planar social being (to synthesise and interpret the findings from a critical realist perspective), this research highlights the unique context of up-skilling opportunities and practices in the marine sector and reveals the crucial role of agency in workplace practices. This leads to a better understanding of the up-skilling opportunities and practices of marine professionals in South Africa, which ultimately contributes towards improved human capital development in the biodiversity and environmental sectors. Through offering more complex insights into the forms of learning and up-skilling, as well as a distinct methodological contribution, this research has broader relevance for workplace learning research.
- Full Text:
- Authors: Bell, Caroline Margaret
- Date: 2019
- Subjects: Biodiversity conservation -- South Africa , Human capital -- South Africa , Marine sciences -- Employees -- South Africa -- Training of , Biodiversity Human Capital Development Strategy (South Africa)
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/93966 , vital:30977
- Description: South Africa is characterised by cultural and biological diversity which constitute a unique context in which to conduct educational research, such as this doctoral study looking at human capital development in the marine biodiversity context. The drive for transformation in the country is also a major factor to consider when researching any sector of the economy, in this case, the biodiversity sector. The biodiversity sector includes organisations involved in biodiversity conservation, research and management. Previous research in the sector has found a clear need for well-thought out workplace skills plans within conservation and research organisations. The national Biodiversity Human Capital Development Strategy that was produced in 2010 by the South African National Biodiversity Institute outlines how all the organisations involved in the biodiversity sector of South Africa need to participate in strengthening the sector through a range of human capital development strategies. This includes extending the existing human capacity of managers and scientists who are already in the workplace, i.e. up-skilling. In particular, ‘scarce’ skills, as identified by the national Environmental Sector Skills Plan need further attention and development. The scarce skills relevant to this study are: protected area managers; ecosystem managers and post-graduate researchers, hence the focus on managers and scientists in this research. The marine sector falls within the biodiversity sector and it faces multiple conservation challenges which are complex and it is therefore essential to have skilled and capable managers and scientists in place. By investigating the up-skilling opportunities and practices available to these marine professionals, the goal is to understand if and how learning takes place in the marine sector of South Africa. The main research question of this study is: How do up-skilling opportunities and practices enable learning in, through and for the workplace, by marine professionals? In addition, three sub-questions provide finer details and introduce the central concepts of the research: I. What up-skilling opportunities and professional practices exist in or for, marine research and conservation organisations and how are they constituted and enacted via practice-based sayings, doings and relatings? II. How do the individuals learn and exercise their agency within the socio-material realities of the marine scientific and management context, through making use of up-skilling opportunities that are both formal (e.g. course based) and informal? III. How do generative mechanisms shape the constitution and enactment of up-skilling opportunities and practices, and the learning and agency of marine professionals (scientists and managers)? The theoretical work of this study consisted of, first, considering sensitising concepts which included: defining skill and knowledge; considering what an up-skilling opportunity might look like; workplace learning (both formal and informal learning); professional practices, lifelong learning or adult education, and agency in the workplace. Critical realism was then employed as the meta-theory that underlabours this research, while the substantive theories used for analysis purposes were socio-materialism and practice theory. Of course, critical realism is a socio-material theory itself, and Bhaskar’s four-planar social being or Social Cube was used to interpret and synthesise the findings in the data chapters. The methodological framework of this study explores the implications of critical realism for research design and analysis and includes a contextual profiling phase, semi-structured interviews, analysis of documents and peer-reviewed papers, as well as observations. There are nine case studies that form the focus of this research and in total 18 research participants were involved. Data analysis included abduction and retroduction as the primary modes of inference and the main analytical tool was the framework of practice architectures where I took the ‘sayings’, ‘doings’ and ‘relatings’ as themes. Further themes were developed from the other relevant theories used in this study; hence socio-materialism, learning, agency, and formal and informal opportunities, were also used as themes when coding the data. Issues around validity, ethics and reflexivity are key elements of the research design and were carefully considered throughout the research process. The principal data chapters are structured in such a way that each sub-question is considered and ultimately the findings are presented in the form of generative mechanisms which included: the politics of social transformation and knowledge as a driving force of up-skilling; the influence of individual disposition and passion or will; the importance of the socio-material realities and realistic expectations; and how relationality is critical for the marine sector. Agency was a cross-cutting theme in all the discussions around learning, practices and the role of the material, and was highly influential on the mechanisms that have been described in this study. The experiences, events and mechanisms that were uncovered in this research provide insight into the forms of learning as these relate to up-skilling that occur in the marine sector, as well as the complex relationships between formal and informal learning. The professional practices that occur in the everyday working lives of the marine professionals were shown to be an integral part of the learning process, while formal, certified opportunities are important for strengthening the field and building conservation competence in the country. By uncovering the deeper structures and mechanisms that have power and causal efficacy when it comes to up-skilling opportunities, learning and professional practices, this study has contributed to the field of environmental education as it shows how up-skilling processes operate in complex formations that involve formal and informal learning processes in workplaces. The study also offers a more nuanced view of the relational objects in this field, such as up-skilling and workplace learning, via the inclusion of a socio-material analysis. Through a theoretical and methodological framework that focused on the material using the tools of practice theory and Bhaskar’s depth ontology and four-planar social being (to synthesise and interpret the findings from a critical realist perspective), this research highlights the unique context of up-skilling opportunities and practices in the marine sector and reveals the crucial role of agency in workplace practices. This leads to a better understanding of the up-skilling opportunities and practices of marine professionals in South Africa, which ultimately contributes towards improved human capital development in the biodiversity and environmental sectors. Through offering more complex insights into the forms of learning and up-skilling, as well as a distinct methodological contribution, this research has broader relevance for workplace learning research.
- Full Text:
Understanding the perceived role of mobile media in relation to development in a South African rural area
- Authors: Chatikobo, Tatenda
- Date: 2019
- Subjects: Mobile communication systems -- South Africa , Internet telephony -- South Africa , Mobile communication systems -- Social aspects -- South Africa , Internet telephony -- Social aspects --South Africa
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/95360 , vital:31148
- Description: This study explores the different perceptions of mobile media in relation to development within Dwesa, a marginalised rural community in South Africa. The proliferation of mobile phones and increasing access to the internet in Africa, and South Africa in particular, is extensively documented and attempts have been made to explore its impact on development. Drawing on adapted aspects of the Diffusion of innovation theory (DoI), the study seeks to understand the relative advantage, compatibility with needs and values, and observable benefits of using mobile media for a rural community. I provide a critical discussion of the concept of development and its relationship with digital technologies and innovation. I reflect on the Diffusion of innovation theory, highlighting its critiques, adaptations and modifications in studies, particularly in the Global South. The present study employs a qualitative methodology and relies on focus groups, semi-structured interviews and observation as methods of data collection. Participants were divided into three focus groups based on Rogers classification of innovativeness (early adopters, majority adopters and late/non-adopters) and I conducted two follow-up interviews with participants of each focus group. I analysed the data thematically. Research participants identified several areas where mobile media contributed to development and positive change, such as lowering the cost of access to information and communication, staying in touch with distant relatives, increasing access to services and providing entertainment, especially among young people. The participants noted that despite these positive changes, that mobile media on its own cannot be expected to address challenges of infrastructure and public service delivery. Research findings also revealed that mobile media might interfere with socio-cultural values of respect, human dignity and privacy. I conclude that, while mobile media is generally considered as beneficial, its critical role in improving the socio-economic conditions of people in Dwesa still remains in doubt. The study provides an opportunity to further investigate the compatibility of mobile media with socio-cultural values along the lines of age and gender, and address issues of digital skills and digital marginalisation.
- Full Text:
- Authors: Chatikobo, Tatenda
- Date: 2019
- Subjects: Mobile communication systems -- South Africa , Internet telephony -- South Africa , Mobile communication systems -- Social aspects -- South Africa , Internet telephony -- Social aspects --South Africa
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/95360 , vital:31148
- Description: This study explores the different perceptions of mobile media in relation to development within Dwesa, a marginalised rural community in South Africa. The proliferation of mobile phones and increasing access to the internet in Africa, and South Africa in particular, is extensively documented and attempts have been made to explore its impact on development. Drawing on adapted aspects of the Diffusion of innovation theory (DoI), the study seeks to understand the relative advantage, compatibility with needs and values, and observable benefits of using mobile media for a rural community. I provide a critical discussion of the concept of development and its relationship with digital technologies and innovation. I reflect on the Diffusion of innovation theory, highlighting its critiques, adaptations and modifications in studies, particularly in the Global South. The present study employs a qualitative methodology and relies on focus groups, semi-structured interviews and observation as methods of data collection. Participants were divided into three focus groups based on Rogers classification of innovativeness (early adopters, majority adopters and late/non-adopters) and I conducted two follow-up interviews with participants of each focus group. I analysed the data thematically. Research participants identified several areas where mobile media contributed to development and positive change, such as lowering the cost of access to information and communication, staying in touch with distant relatives, increasing access to services and providing entertainment, especially among young people. The participants noted that despite these positive changes, that mobile media on its own cannot be expected to address challenges of infrastructure and public service delivery. Research findings also revealed that mobile media might interfere with socio-cultural values of respect, human dignity and privacy. I conclude that, while mobile media is generally considered as beneficial, its critical role in improving the socio-economic conditions of people in Dwesa still remains in doubt. The study provides an opportunity to further investigate the compatibility of mobile media with socio-cultural values along the lines of age and gender, and address issues of digital skills and digital marginalisation.
- Full Text:
Using a multi-method approach to understand the movement patterns and the associated environmental correlates of an iconic West African recreational fish
- Authors: Winkler, Alexander Claus
- Date: 2019
- Subjects: Carangidae fishing , Carangidae -- Migration , Carangidae -- Namibia , Carangidae -- Angola , Fish tagging , Carangidae -- Benguela Current , Underwater acoustic telemetry , Ocean temperature -- Physiological effect , Fishes -- Effect of temperature on
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/76530 , vital:30597
- Description: The leerfish (Lichia amia), is a large, primarily coastal recreational fish species with a distribution extending from Portugal down the west coast of African to southern Mozambique. Owing to its large size (30 kg), strong fighting abilities and habit of taking surface artificial lures, this species has taken on an iconic stature among shore-based recreational anglers. Its reputation has made it an important angling tourism species that makes an important contribution to the economy of developing countries. For example, the species brought US$243 per harvested kilogramme into the local southern Angola economy. Despite its high value, little is known about its movement patterns in the northern Benguela coastal region, a region which includes southern Angola and northern Namibia. While much is known about the migratory patterns of the South African stock of L. amia, recent molecular studies have shown that the northern Benguela stock of L. amia has been isolated from the South African population for at least two million years, a consequence of the development of the cold Lüderitz upwelling cell in southern Namibia. Although the global population of L. amia is considered a single species, prominent biogeographic barriers within its distribution and subtle morphological differences between specimens captured within its tropical versus warm-temperate distribution suggest otherwise. A multi-method approach incorporating passive acoustic telemetry (PAT), recreational catch-per-unit-effort (CPUE) and conventional tagging (CT) in southern Angola, as well as recreational fisher-ecological knowledge (FEK) from Namibia, was used to investigate the large-scale movement patterns of L. amia within the northern Benguela coastal region. While each method had its own associated limitations, the combination provided a holistic picture of the population's seasonal migratory patterns. Furthermore, PAT successfully identified partial migration with 25% vs 75% of monitored fish exhibiting resident (movements < 100 km) or migratory (movements > 100 km) behaviour, respectively. Further behavioural diversity was observed with ‘resident’, ‘roaming’ and ‘embayment’ contingents identified based on varying levels of affinity to certain habitats. The presence of both resident and migratory individuals within the northernmost study during June and July, combined with available biological information, suggested that area-specific spawning may take place. While PAT, CPUE and CT largely aligned in determining area specific high-area use, results from network analyses and mixed effects models conducted on the PAT data supported the spawning hypothesis, with anomalous behaviour around specific receivers during the spawning season. All fish, regardless of behavioural contingent, displayed similar movement behaviour during the spawning season and this was driven by factors generally associated with reproduction, such as lunar illumination. Interestingly, these drivers were different from those that determined the area specific use of individuals outside of the spawning season. The environmental drivers of longshore migration into the northern study site were identified as a decline in water temperature and shorter day lengths. The results of this study highlight the importance of using a multi-method approach in determining migratory movement behaviour, area specific area use, and stock structure of key fisheries species. The identification of different behavioural contingents highlights the importance of acknowledging individual variation in movement and habitat-use patterns. This is particularly relevant as future climate change and spatiotemporal variation in fishing effort may artificially skew natural selection processes to favour certain behavioural groups. This study also highlighted the importance of scientists forming relationships with resource-users, such as recreational angling lodges in areas where limited research has been conducted. This is particularly relevant within the West African context where little is known about many of the fish species that are being increasingly targeted by tourism angling ventures.
- Full Text:
- Authors: Winkler, Alexander Claus
- Date: 2019
- Subjects: Carangidae fishing , Carangidae -- Migration , Carangidae -- Namibia , Carangidae -- Angola , Fish tagging , Carangidae -- Benguela Current , Underwater acoustic telemetry , Ocean temperature -- Physiological effect , Fishes -- Effect of temperature on
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/76530 , vital:30597
- Description: The leerfish (Lichia amia), is a large, primarily coastal recreational fish species with a distribution extending from Portugal down the west coast of African to southern Mozambique. Owing to its large size (30 kg), strong fighting abilities and habit of taking surface artificial lures, this species has taken on an iconic stature among shore-based recreational anglers. Its reputation has made it an important angling tourism species that makes an important contribution to the economy of developing countries. For example, the species brought US$243 per harvested kilogramme into the local southern Angola economy. Despite its high value, little is known about its movement patterns in the northern Benguela coastal region, a region which includes southern Angola and northern Namibia. While much is known about the migratory patterns of the South African stock of L. amia, recent molecular studies have shown that the northern Benguela stock of L. amia has been isolated from the South African population for at least two million years, a consequence of the development of the cold Lüderitz upwelling cell in southern Namibia. Although the global population of L. amia is considered a single species, prominent biogeographic barriers within its distribution and subtle morphological differences between specimens captured within its tropical versus warm-temperate distribution suggest otherwise. A multi-method approach incorporating passive acoustic telemetry (PAT), recreational catch-per-unit-effort (CPUE) and conventional tagging (CT) in southern Angola, as well as recreational fisher-ecological knowledge (FEK) from Namibia, was used to investigate the large-scale movement patterns of L. amia within the northern Benguela coastal region. While each method had its own associated limitations, the combination provided a holistic picture of the population's seasonal migratory patterns. Furthermore, PAT successfully identified partial migration with 25% vs 75% of monitored fish exhibiting resident (movements < 100 km) or migratory (movements > 100 km) behaviour, respectively. Further behavioural diversity was observed with ‘resident’, ‘roaming’ and ‘embayment’ contingents identified based on varying levels of affinity to certain habitats. The presence of both resident and migratory individuals within the northernmost study during June and July, combined with available biological information, suggested that area-specific spawning may take place. While PAT, CPUE and CT largely aligned in determining area specific high-area use, results from network analyses and mixed effects models conducted on the PAT data supported the spawning hypothesis, with anomalous behaviour around specific receivers during the spawning season. All fish, regardless of behavioural contingent, displayed similar movement behaviour during the spawning season and this was driven by factors generally associated with reproduction, such as lunar illumination. Interestingly, these drivers were different from those that determined the area specific use of individuals outside of the spawning season. The environmental drivers of longshore migration into the northern study site were identified as a decline in water temperature and shorter day lengths. The results of this study highlight the importance of using a multi-method approach in determining migratory movement behaviour, area specific area use, and stock structure of key fisheries species. The identification of different behavioural contingents highlights the importance of acknowledging individual variation in movement and habitat-use patterns. This is particularly relevant as future climate change and spatiotemporal variation in fishing effort may artificially skew natural selection processes to favour certain behavioural groups. This study also highlighted the importance of scientists forming relationships with resource-users, such as recreational angling lodges in areas where limited research has been conducted. This is particularly relevant within the West African context where little is known about many of the fish species that are being increasingly targeted by tourism angling ventures.
- Full Text:
Using a social-ecological systems approach to investigate hillslope seep wetlands ecosystem structure and functionality in the Tsitsa River catchment, Eastern Cape, South Africa
- Authors: Libala, Notiswa
- Date: 2019
- Subjects: Wetland management -- South Africa -- Eastern Cape , Wetland ecology -- South Africa -- Eastern Cape , Wetland conservation -- South Africa -- Eastern Cape , Slopes (Physical geography) -- South Africa -- Eastern Cape , Vegetation management -- South Africa -- Tsitsa River Catchment , Land degradation -- Control -- South Africa -- Tsitsa River Catchment , Grazing -- Environmental aspects -- South Africa -- Tsitsa River Catchment , Ecosystem management -- South Africa -- Tsitsa River Catchment , Wetland plants -- Effect of grazing on
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/115936 , vital:34270
- Description: Wetlands are critical ecosystems that can provide services of great social, economic and environmental value to the society. Yet, in South Africa, hillslope seep wetlands are among the most threatened ecosystems due to human-induced activities and are disappearing rapidly. Further, despite the potential vulnerability of hillslope seep wetland to disturbances, and their criticality in relation to all year round provision of forage for livestock grazing, they are among the most poorly studied wetland systems. Using a social-ecological system framing, and drawing on a range of ecological and social sciences methods, this study shed light on ways in which an integrative approach can contribute to sustainable utilisation of hillslope seep wetlands in the Tsitsa River catchment in the Eastern Cape province of South Africa. The study specific objectives were to i) evaluate the performance of Floristic Quality Assessment Index (FQAI), WET-Health and Floristic Assessment Quotient for Wetlands Index (FQAWet) indices for assessing hillslope seep wetlands ecological health ii) develop a trait-based approach for assessing the potential resilience and vulnerability of hillslope seep wetland plant species to disturbances, iii) assess the role of hillslope seep wetlands in the local communities in relation to livestock, and explore understanding of local people about the value of hillslope seep wetlands, iv) demonstrate collaborative insights emerging from an integrative social-ecological system research process to inform sustainable management of hillslope seep wetlands. A total of 11 hillslope seep wetlands were visually classified based on the level of erosion. Plant species composition within the wetlands was determined along a 100 m line transects across the hillslope wetland sites. 5 quadrats of 0.2m2 were also placed along transect for vegetation collection and cover. The plant species collected were used to calculate (FQAI) and FQAWet scores to evaluate the condition of hillslope seep wetlands. The degree of human disturbances was assessed using the Anthropogenic Activity Index (AAI), an index for qualitatively assessing the degree of human disturbance based on visual inspection of a wetland site. Factors represented in the AAI, include: (i) surrounding land use intensity; (ii) soil disturbance; (iii) hydrological alteration; (iv) habitat alteration within wetland; (v) vegetation community quality. The vegetation samples were collected in summer 2016 and winter 2017. All assessed indices were regressed against AAI to evaluate their performances. All assessed indices FQAI, FQAWet and WET-Health showed that hillslope seep wetland were impacted by human activities. FQAIall and WET-Health showed the strongest response to AAI in winter, while FQAIdom and FAQWet showed a weak response to AAI in all seasons. Overall, the findings of this study suggest that FQAIall and WET-Health are potentially better tools for assessing the biological conditions of hillslope seep wetland in South Africa. A novel trait-based approach was developed using seven plant traits and 27 trait attributes. Based on the developed approach, plant species were grouped into three potentially vulnerable groups in relation to grazing pressure. It was then predicted that species belonging to the highly vulnerable group would be less dominant at the highly disturbed sites, as well as in the winter season when grazing pressure is at its highest. The result corresponds largely with the seasonal predictions; however this was not the case for sites. The approach developed in this study worked and it was useful for predicting the potential responses of plant species in hillslope seep wetlands to grazing pressure. The success of the approach seasonally could be attributed to the careful selection of the traits, reflecting the mechanistic relationship between the grazing mode of stress on vegetation and trait-mediated biotic response. However, this still need to be refined using accurate vegetation cover methods that might have had impact on the lack of correspondence within sites. The results of the present study revealed that communities largely perceive hillslope seep wetlands as important ecosystems for their livelihoods. They recognise that the importance stems from services provided by the wetlands, particularly for livestock grazing during the dry season. Although hillslope seep wetlands are viewed as important ecosystems for livelihoods, the communities also perceive these wetlands as highly eroded ecosystems. Community members indicate willingness to strengthen local natural resource governance systems, which could lead to better management of hillslope seep wetlands. A range of protective strategies for hillslope seep were suggested by community members, including fencing, active herding and rotational grazing. The study suggests that active involvement of local communities is critical to the successful management of natural resources. The study highlights the need to consider the role of local people as influential components within social-ecological systems in order to promote effective management and conservation interventions of hillslope seep wetlands. Overall, the study highlights the criticality of an integrative social-ecological system approach for holistic management of hillslope seep wetlands within the studied catchment.
- Full Text:
- Authors: Libala, Notiswa
- Date: 2019
- Subjects: Wetland management -- South Africa -- Eastern Cape , Wetland ecology -- South Africa -- Eastern Cape , Wetland conservation -- South Africa -- Eastern Cape , Slopes (Physical geography) -- South Africa -- Eastern Cape , Vegetation management -- South Africa -- Tsitsa River Catchment , Land degradation -- Control -- South Africa -- Tsitsa River Catchment , Grazing -- Environmental aspects -- South Africa -- Tsitsa River Catchment , Ecosystem management -- South Africa -- Tsitsa River Catchment , Wetland plants -- Effect of grazing on
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/115936 , vital:34270
- Description: Wetlands are critical ecosystems that can provide services of great social, economic and environmental value to the society. Yet, in South Africa, hillslope seep wetlands are among the most threatened ecosystems due to human-induced activities and are disappearing rapidly. Further, despite the potential vulnerability of hillslope seep wetland to disturbances, and their criticality in relation to all year round provision of forage for livestock grazing, they are among the most poorly studied wetland systems. Using a social-ecological system framing, and drawing on a range of ecological and social sciences methods, this study shed light on ways in which an integrative approach can contribute to sustainable utilisation of hillslope seep wetlands in the Tsitsa River catchment in the Eastern Cape province of South Africa. The study specific objectives were to i) evaluate the performance of Floristic Quality Assessment Index (FQAI), WET-Health and Floristic Assessment Quotient for Wetlands Index (FQAWet) indices for assessing hillslope seep wetlands ecological health ii) develop a trait-based approach for assessing the potential resilience and vulnerability of hillslope seep wetland plant species to disturbances, iii) assess the role of hillslope seep wetlands in the local communities in relation to livestock, and explore understanding of local people about the value of hillslope seep wetlands, iv) demonstrate collaborative insights emerging from an integrative social-ecological system research process to inform sustainable management of hillslope seep wetlands. A total of 11 hillslope seep wetlands were visually classified based on the level of erosion. Plant species composition within the wetlands was determined along a 100 m line transects across the hillslope wetland sites. 5 quadrats of 0.2m2 were also placed along transect for vegetation collection and cover. The plant species collected were used to calculate (FQAI) and FQAWet scores to evaluate the condition of hillslope seep wetlands. The degree of human disturbances was assessed using the Anthropogenic Activity Index (AAI), an index for qualitatively assessing the degree of human disturbance based on visual inspection of a wetland site. Factors represented in the AAI, include: (i) surrounding land use intensity; (ii) soil disturbance; (iii) hydrological alteration; (iv) habitat alteration within wetland; (v) vegetation community quality. The vegetation samples were collected in summer 2016 and winter 2017. All assessed indices were regressed against AAI to evaluate their performances. All assessed indices FQAI, FQAWet and WET-Health showed that hillslope seep wetland were impacted by human activities. FQAIall and WET-Health showed the strongest response to AAI in winter, while FQAIdom and FAQWet showed a weak response to AAI in all seasons. Overall, the findings of this study suggest that FQAIall and WET-Health are potentially better tools for assessing the biological conditions of hillslope seep wetland in South Africa. A novel trait-based approach was developed using seven plant traits and 27 trait attributes. Based on the developed approach, plant species were grouped into three potentially vulnerable groups in relation to grazing pressure. It was then predicted that species belonging to the highly vulnerable group would be less dominant at the highly disturbed sites, as well as in the winter season when grazing pressure is at its highest. The result corresponds largely with the seasonal predictions; however this was not the case for sites. The approach developed in this study worked and it was useful for predicting the potential responses of plant species in hillslope seep wetlands to grazing pressure. The success of the approach seasonally could be attributed to the careful selection of the traits, reflecting the mechanistic relationship between the grazing mode of stress on vegetation and trait-mediated biotic response. However, this still need to be refined using accurate vegetation cover methods that might have had impact on the lack of correspondence within sites. The results of the present study revealed that communities largely perceive hillslope seep wetlands as important ecosystems for their livelihoods. They recognise that the importance stems from services provided by the wetlands, particularly for livestock grazing during the dry season. Although hillslope seep wetlands are viewed as important ecosystems for livelihoods, the communities also perceive these wetlands as highly eroded ecosystems. Community members indicate willingness to strengthen local natural resource governance systems, which could lead to better management of hillslope seep wetlands. A range of protective strategies for hillslope seep were suggested by community members, including fencing, active herding and rotational grazing. The study suggests that active involvement of local communities is critical to the successful management of natural resources. The study highlights the need to consider the role of local people as influential components within social-ecological systems in order to promote effective management and conservation interventions of hillslope seep wetlands. Overall, the study highlights the criticality of an integrative social-ecological system approach for holistic management of hillslope seep wetlands within the studied catchment.
- Full Text:
Using captive seabirds to assess knowledge gaps in stable isotope analysis of diets
- Authors: Micklem, Isabel Andrea
- Date: 2019
- Subjects: Stable isotopes -- Analysis African penguin -- South Africa Breeding
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/65101 , vital:28686
- Description: Stable isotope (SI) ratios of carbon (δ13C) and nitrogen (δ15N) are now widely used as biomarkers in ecological studies to provide information about food web structuring. However, understanding trophic relationships using SI analysis requires not only knowledge of SI values of predator and prey, but also accurate discrimination factors (DFs), which can differ among species and by physiological state. This thesis examined three questions using captive birds from the South African Foundation for the Conservation of Coastal Birds (SANCCOB). First, the effects of ontogeny on δ13C and δ15N ratios of African penguins (Spheniscus demersus) were assessed. Blood samples were collected from penguins in four age classes (P3 chicks, blues, juveniles and adults) concurrently with their diet (sardine (Sardinops sagax) and formula). Second, to assess the influence of breeding physiology on SI ratios, the blood of ten breeding pairs of penguins was sampled over a five-month period from June to October 2016. Following laying, each pair was categorised into one of three (four for whole blood) egg production phases (initial yolk deposition, rapid yolk deposition and post-laying) and their influences on SI ratios were tested. Third, species differences in DFs were evaluated for African penguins, kelp and Hartlaub’s gulls (Larus dominicanus and L. hartlaubii), greater crested terns (Thalasseus bergii) and Cape cormorants (Phalacrocorax capensis). Flying birds were mostly fed sardine with a small but unknown amount of sardinella (Sardinella aurita), DFs were therefore estimated for a 50:50 sardine:sardinella diet, a 75:25 sardine:sardinella diet and a 100% sardine diet for each flying bird species. The DFs were assessed for the whole blood (WB), red blood cells (RBC), plasma (PL) and delipidated plasma of the penguins, and only WB for the flying birds as well as flesh, whole fish, delipidated flesh and delipidated whole fish for fish species, and for formula. Results indicated that age influenced both the δ13C and δ15N of WB, only the δ15N of RBC and the δ13C of delipidated PL. The assessment of breeding physiology yielded a significant interaction between the effects of egg production phase and sex on the δ13C of WB; females had significantly lower δ13C in the rapid yolk deposition phase than the other two phases and all males. The δ13C of PL was affected only by sex, with females having a significantly lower δ13C value than males. Neither physiological state nor sex influenced the other blood components. Differences were found among the three DFs in the non-penguin species, but not for all consumer – prey tissue combinations. There were also significant differences among species with a DF calculated from a diet with the most probable prey proportions eaten. Depending on the combination of consumer and prey tissue used to calculate the DF, a different conclusion regarding trophic information can be reached. A literature review updated with the present data showed that no general pattern or grouping of similar species with regards to DF values could be drawn, highlighting the importance of determining species- and tissue-specific DFs. Thus age, egg production, tissue and species all influenced the SI values of bird blood and therefore their DFs. Not all physiological conditions affect all blood components in the same way, making different components more or less sensitive to physiological influences. Though their influence is at a small enough scale that it is unlikely to hamper correct conclusion in ecological studies, it is crucial that these factors are considered when using SI analysis (SIA). When uncertainties exist for some coefficients in wild studies, SIA should therefore be combined to other dietary techniques to determine the food web structure as best as possible.
- Full Text:
- Authors: Micklem, Isabel Andrea
- Date: 2019
- Subjects: Stable isotopes -- Analysis African penguin -- South Africa Breeding
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/65101 , vital:28686
- Description: Stable isotope (SI) ratios of carbon (δ13C) and nitrogen (δ15N) are now widely used as biomarkers in ecological studies to provide information about food web structuring. However, understanding trophic relationships using SI analysis requires not only knowledge of SI values of predator and prey, but also accurate discrimination factors (DFs), which can differ among species and by physiological state. This thesis examined three questions using captive birds from the South African Foundation for the Conservation of Coastal Birds (SANCCOB). First, the effects of ontogeny on δ13C and δ15N ratios of African penguins (Spheniscus demersus) were assessed. Blood samples were collected from penguins in four age classes (P3 chicks, blues, juveniles and adults) concurrently with their diet (sardine (Sardinops sagax) and formula). Second, to assess the influence of breeding physiology on SI ratios, the blood of ten breeding pairs of penguins was sampled over a five-month period from June to October 2016. Following laying, each pair was categorised into one of three (four for whole blood) egg production phases (initial yolk deposition, rapid yolk deposition and post-laying) and their influences on SI ratios were tested. Third, species differences in DFs were evaluated for African penguins, kelp and Hartlaub’s gulls (Larus dominicanus and L. hartlaubii), greater crested terns (Thalasseus bergii) and Cape cormorants (Phalacrocorax capensis). Flying birds were mostly fed sardine with a small but unknown amount of sardinella (Sardinella aurita), DFs were therefore estimated for a 50:50 sardine:sardinella diet, a 75:25 sardine:sardinella diet and a 100% sardine diet for each flying bird species. The DFs were assessed for the whole blood (WB), red blood cells (RBC), plasma (PL) and delipidated plasma of the penguins, and only WB for the flying birds as well as flesh, whole fish, delipidated flesh and delipidated whole fish for fish species, and for formula. Results indicated that age influenced both the δ13C and δ15N of WB, only the δ15N of RBC and the δ13C of delipidated PL. The assessment of breeding physiology yielded a significant interaction between the effects of egg production phase and sex on the δ13C of WB; females had significantly lower δ13C in the rapid yolk deposition phase than the other two phases and all males. The δ13C of PL was affected only by sex, with females having a significantly lower δ13C value than males. Neither physiological state nor sex influenced the other blood components. Differences were found among the three DFs in the non-penguin species, but not for all consumer – prey tissue combinations. There were also significant differences among species with a DF calculated from a diet with the most probable prey proportions eaten. Depending on the combination of consumer and prey tissue used to calculate the DF, a different conclusion regarding trophic information can be reached. A literature review updated with the present data showed that no general pattern or grouping of similar species with regards to DF values could be drawn, highlighting the importance of determining species- and tissue-specific DFs. Thus age, egg production, tissue and species all influenced the SI values of bird blood and therefore their DFs. Not all physiological conditions affect all blood components in the same way, making different components more or less sensitive to physiological influences. Though their influence is at a small enough scale that it is unlikely to hamper correct conclusion in ecological studies, it is crucial that these factors are considered when using SI analysis (SIA). When uncertainties exist for some coefficients in wild studies, SIA should therefore be combined to other dietary techniques to determine the food web structure as best as possible.
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Using four different methods to reach a taxonomic conclusion in dung beetles (Scarabaeinae)
- Authors: Deschodt, Christian Michel
- Date: 2019
- Subjects: Dung beetles -- Classification , Scarabaeidae -- Classification
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/67845 , vital:29156
- Description: Four different techniques to make taxonomic decisions concerning different species in Scarabaeinae are being investigated. Firstly, I made measurements of the body dimensions which are plotted on a two dimensional graph. This method is successfully used to erect one new species, Copris crassus Deschodt and Davis, 2015, and to establish the synonymy of Copris bihamatus Balthasar, 1965 with Copris fidius (Olivier, 1789). Thereafter the classical or traditional comparative method is used to propose seven new species Scarabaeolus soutpansbergensis (Deschodt and Davis 2015), Scarabaeolus megaparvulus (Davis and Deschodt 2015), Scarabaeolus niemandi (Deschodt and Davis 2015), Scarabaeolus carniphilus (Davis and Deschodt 2015), Scarabaeolus ermienae (Deschodt and Davis 2015), Scarabaeolus planipennis (Davis and Deschodt 2015) and Scarabaeolus afronitidus (Davis and Deschodt 2015) and formally synonymise Scarabaeolus vansoni (Ferreira, 1958) with Scarabaeolus lucidulus (Boheman, 1860) and Scarabaeolus xavieri (Ferreira, 1968) with Scarabaeolus andreaei (zur Strassen, 1963). Morphometric measurements of external structures of a group of flightless relict beetles in the tribe Canthonini are used to compile a nexus file which is analysed with computer software. The interpretation of these results is used here to support the erection of a new genus Drogo Deschodt, Davis & Scholtz 2016, Lastly I analysed the DNA sequences of specimens from different species belonging to a species complex in the genus Epirinus Reiche, 1841 occurring over a wide geographic range. These sequences are used together with external morphological characters to propose the synonymy of Epirinus hluhluwensis Medina & Scholtz 2005 and Epirinus ngomae Medina & Scholtz 2005 with Epirinus davisi Scholtz & Howden 1987.
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- Authors: Deschodt, Christian Michel
- Date: 2019
- Subjects: Dung beetles -- Classification , Scarabaeidae -- Classification
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/67845 , vital:29156
- Description: Four different techniques to make taxonomic decisions concerning different species in Scarabaeinae are being investigated. Firstly, I made measurements of the body dimensions which are plotted on a two dimensional graph. This method is successfully used to erect one new species, Copris crassus Deschodt and Davis, 2015, and to establish the synonymy of Copris bihamatus Balthasar, 1965 with Copris fidius (Olivier, 1789). Thereafter the classical or traditional comparative method is used to propose seven new species Scarabaeolus soutpansbergensis (Deschodt and Davis 2015), Scarabaeolus megaparvulus (Davis and Deschodt 2015), Scarabaeolus niemandi (Deschodt and Davis 2015), Scarabaeolus carniphilus (Davis and Deschodt 2015), Scarabaeolus ermienae (Deschodt and Davis 2015), Scarabaeolus planipennis (Davis and Deschodt 2015) and Scarabaeolus afronitidus (Davis and Deschodt 2015) and formally synonymise Scarabaeolus vansoni (Ferreira, 1958) with Scarabaeolus lucidulus (Boheman, 1860) and Scarabaeolus xavieri (Ferreira, 1968) with Scarabaeolus andreaei (zur Strassen, 1963). Morphometric measurements of external structures of a group of flightless relict beetles in the tribe Canthonini are used to compile a nexus file which is analysed with computer software. The interpretation of these results is used here to support the erection of a new genus Drogo Deschodt, Davis & Scholtz 2016, Lastly I analysed the DNA sequences of specimens from different species belonging to a species complex in the genus Epirinus Reiche, 1841 occurring over a wide geographic range. These sequences are used together with external morphological characters to propose the synonymy of Epirinus hluhluwensis Medina & Scholtz 2005 and Epirinus ngomae Medina & Scholtz 2005 with Epirinus davisi Scholtz & Howden 1987.
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Vowel harmony in isiXhosa: an OT and acoustic study of [ATR]
- Authors: Kilian, Kelly
- Date: 2019
- Subjects: Grammar, Comparative and general -- Vowel harmony , Xhosa language -- Vowels , Xhosa language -- Phonetics
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/67678 , vital:29128
- Description: The vowel harmony system in isiXhosa is centred on a process of vowel raising. All mid-vowels preceding a high vowel take on the feature advanced tongue root (ATR) (e.g. thɛnga ‘buy’ → thengisa ‘sell’; bɔna 'see' → bonisa 'cause to see') (Harris 1987). The process of mid-vowel assimilation for the feature [+ATR] is consistent in all instances in which the mid-vowel occurs preceding a high vowel trigger, unless harmony is blocked by the low opaque vowel [a]. This is the analysis presented in Jokweni & Thipa (1996) the only previous literature to address the vowel harmony process of isiXhosa in detail. As an alternative approach to the rule-based phonology applied in the analysis presented by Jokweni & Thipa (1996), I propose the introduction of Optimality theory (OT) (Prince & Smolensky 1993, Bakovic 2000, and Pulleyblank 2002). I will present a map of the harmony system of isiXhosa using OT, while also presenting acoustic data to supplement the selected examples provided in Jokweni & Thipa (1996). This acoustic investigation will determine whether the harmonic feature is ATR, and how this feature patterns among vowels in different phonological contexts. In this paper vowel harmony is achieved through the implication of numerous rules, and with very specific directional and prosodic limitations on the spread of [+ATR]. Using generalisations based on my own collected data as well as those reported in previous literature, I have developed a constraint ranking to account for the harmony process in isiXhosa. By adapting the No-disagreement approach to harmony (Pulleyblank 2002), the final constraint ranking has the capacity to derive the optimal phonetic candidate for every harmony case. A selection of spread constraints is used to account for the raising as well as blocking processes, by driving either regressive or progressive spreading. Within the original No-disagreement approach a spread constraint would recognised only one feature in its prohibition of disagreeing segments. However, in the adapted approach the spread constraint driving [+ATR] assimilation is combined with a feature of correspondence (Krämer 2001) which considers the height as well as the ATR value of the sequential segments. The constraint is therefore adapted to consider more than one feature and is not activated unless the sequential segments agree for this particular feature. The regressive spread constraint is therefore only activated when the consecutive segments have an agreeing height value. The introduction of this adaptation was necessary to provide a more nuanced OT approach with the capacity to effectively characterise the idiosyncrasies observed in this harmony pattern. The harmony constraints are therefore no longer contradict one another by simultaneously driving harmony in opposite directions. Furthermore, the direct acoustic analysis is completed by means of the PRAAT software, to answer the salient question of the definitive harmonic feature. To provide a multiplicity of empirical evidence I have recorded utterances containing a number of vowel combinations. Each combination positions the alternating mid-vowels in a particular phonological context from which instances of ATR alternations have been extracted and phonetically analysed. Using the generalisations reported in Jokweni & Thipa (1996) as a starting point, the acoustic signal of each mid-vowel within a set phonological context is annotated for a predicted ATR value. Hence, if a mid-vowel occurs preceding a high vowel it is annotated as [+ATR] etc. The data sets representing each of the mid-variants found in a specific phonological context are then plotted into vowel charts and compared by means of statistical analysis (Baayen 2008, Bluman 2000). The results are then used to determine whether any significant phonetic alternation is occurring, and what the acoustic distinction between [+ATR] & [-ATR] variants is essentially comprised of. The final acoustic results indicate a significant difference between the mid-vowel ATR variants extracted from specific phonological contexts. Hence, due to co-articulatory effects or some other phonological influence the realisation of [+/-ATR] variants exist along a spectrum, and are therefore not phonetically consistent, but indicate a different acoustic make-up across the various groups.
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- Authors: Kilian, Kelly
- Date: 2019
- Subjects: Grammar, Comparative and general -- Vowel harmony , Xhosa language -- Vowels , Xhosa language -- Phonetics
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/67678 , vital:29128
- Description: The vowel harmony system in isiXhosa is centred on a process of vowel raising. All mid-vowels preceding a high vowel take on the feature advanced tongue root (ATR) (e.g. thɛnga ‘buy’ → thengisa ‘sell’; bɔna 'see' → bonisa 'cause to see') (Harris 1987). The process of mid-vowel assimilation for the feature [+ATR] is consistent in all instances in which the mid-vowel occurs preceding a high vowel trigger, unless harmony is blocked by the low opaque vowel [a]. This is the analysis presented in Jokweni & Thipa (1996) the only previous literature to address the vowel harmony process of isiXhosa in detail. As an alternative approach to the rule-based phonology applied in the analysis presented by Jokweni & Thipa (1996), I propose the introduction of Optimality theory (OT) (Prince & Smolensky 1993, Bakovic 2000, and Pulleyblank 2002). I will present a map of the harmony system of isiXhosa using OT, while also presenting acoustic data to supplement the selected examples provided in Jokweni & Thipa (1996). This acoustic investigation will determine whether the harmonic feature is ATR, and how this feature patterns among vowels in different phonological contexts. In this paper vowel harmony is achieved through the implication of numerous rules, and with very specific directional and prosodic limitations on the spread of [+ATR]. Using generalisations based on my own collected data as well as those reported in previous literature, I have developed a constraint ranking to account for the harmony process in isiXhosa. By adapting the No-disagreement approach to harmony (Pulleyblank 2002), the final constraint ranking has the capacity to derive the optimal phonetic candidate for every harmony case. A selection of spread constraints is used to account for the raising as well as blocking processes, by driving either regressive or progressive spreading. Within the original No-disagreement approach a spread constraint would recognised only one feature in its prohibition of disagreeing segments. However, in the adapted approach the spread constraint driving [+ATR] assimilation is combined with a feature of correspondence (Krämer 2001) which considers the height as well as the ATR value of the sequential segments. The constraint is therefore adapted to consider more than one feature and is not activated unless the sequential segments agree for this particular feature. The regressive spread constraint is therefore only activated when the consecutive segments have an agreeing height value. The introduction of this adaptation was necessary to provide a more nuanced OT approach with the capacity to effectively characterise the idiosyncrasies observed in this harmony pattern. The harmony constraints are therefore no longer contradict one another by simultaneously driving harmony in opposite directions. Furthermore, the direct acoustic analysis is completed by means of the PRAAT software, to answer the salient question of the definitive harmonic feature. To provide a multiplicity of empirical evidence I have recorded utterances containing a number of vowel combinations. Each combination positions the alternating mid-vowels in a particular phonological context from which instances of ATR alternations have been extracted and phonetically analysed. Using the generalisations reported in Jokweni & Thipa (1996) as a starting point, the acoustic signal of each mid-vowel within a set phonological context is annotated for a predicted ATR value. Hence, if a mid-vowel occurs preceding a high vowel it is annotated as [+ATR] etc. The data sets representing each of the mid-variants found in a specific phonological context are then plotted into vowel charts and compared by means of statistical analysis (Baayen 2008, Bluman 2000). The results are then used to determine whether any significant phonetic alternation is occurring, and what the acoustic distinction between [+ATR] & [-ATR] variants is essentially comprised of. The final acoustic results indicate a significant difference between the mid-vowel ATR variants extracted from specific phonological contexts. Hence, due to co-articulatory effects or some other phonological influence the realisation of [+/-ATR] variants exist along a spectrum, and are therefore not phonetically consistent, but indicate a different acoustic make-up across the various groups.
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