The effect of habitat and spatial management on reef fish in an established marine protected area
- Authors: Dames, Vivienne Abigail
- Date: 2021
- Subjects: iSimangaliso Wetland Park (South Africa) -- Management , Reef fishes -- South Africa -- KwaZulu-Natal , Baited remote underwater stereo-video systems (stereo-BRUVs) , Marine parks and reserves -- Monitoring -- South Africa -- KwaZulu-Natal , Fish populations -- Measurement
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/171150 , vital:42024
- Description: The persistence of harvested fish populations in the Anthropocene will be determined, above all, by how they respond to the interacting effects of climate change and fisheries exploitation. Predicting how populations will respond to both these threats is essential for any adaptive and sustainable management strategy. The response of fish populations to climate change is underpinned by physiological rates and tolerances, and emerging evidence suggests there may be physiological-based selection in capture fisheries. By quantifying important physiological rates of a model species, the endemic seabream, Chrysoblephus laticeps, across ecologically relevant thermal gradients and from populations subjected to varying intensities of commercial exploitation, this thesis aimed to 1) provide the first physiologically grounded climate resilience assessment for a South African linefish species, and 2) elucidate whether exploitation can drive populations to less physiologically resilient states in response to climate change. To identify physiologically limiting sea temperatures and to determine if exploitation alters physiological trait distributions, an intermittent flow respirometry experiment was used to test the metabolic response of spatially protected and exploited populations of C. laticeps to acute thermal variability. Exploited populations showed reduced metabolic phenotype diversity, fewer high-performance aerobic scope phenotypes, and a significantly lower aerobic scope curve across all test temperatures. Although both populations maintained a relatively high aerobic scope across a wide thermal range, their metabolic rates were compromised when extreme cold events were simulated (8 °C), suggesting that predicted future increases in upwelling frequency and intensity may be the primary limiting factor in a more thermally variable future ocean. The increment widths of annuli in the otoliths of C. laticeps from contemporary and historic collections were measured, as a proxy for the annual growth rate of exploited and protected populations. Hierarchical mixed models were used to partition growth variation within and among individuals and ascribe growth to intrinsic and extrinsic effects. The best model for the protected population indicated that the growth response of C. laticeps was poorer during years characterised by a high cumulative upwelling intensity, and better during years characterised by higher mean autumn sea surface temperatures. The exploited population growth chronology was too short to identify an extrinsic growth driver. The growth results again highlight the role of thermal variability in modulating the response of C. laticeps to its ambient environment and indicate that the predicted increases in upwelling frequency and intensity may constrain future growth rates of this species. A metabolic index (ϕ), representing the ratio of O2 supply to demand at various temperatures and oxygen concentrations, was estimated for exploited and protected populations of C. laticeps and used to predict future distribution responses. There was no difference in the laboratory calibrations of ϕ between populations, and all data was subsequently combined into a single piecewise (12 °C) calibrated ϕ model. To predict the distribution of C. laticeps, ϕ was projected across a high-resolution ocean model of the South African coastal zone, and a species distribution model implemented using the random forest algorithm and C. laticeps occurrence points. The future distribution of C. laticeps was estimated by predicting trained models across ocean model projections up to 2100. The best predictor of C. laticeps’ current distribution was minimum monthly ϕ and future predictions indicated only a slight range contraction on either edge of C. laticeps’ distribution by 2100. In order to provide policy makers, currently developing climate change management frameworks for South Africa’s ocean, with a usable output, the results of all research chapters were combined into a marine spatial model. The spatial model identified areas where C. laticeps is predicted to be resilient to climate change in terms of physiology, growth and distribution responses, which can then be prioritised for adaptation measures, such as spatial protection from exploitation. While these results are specific to C. laticeps, the methodology developed to identify areas of climate resilience has broad applications across taxa. From a global perspective, perhaps the most salient points to consider from this case study are the evidence of selective exploitation on physiological traits and the importance of environmental variability, rather than long-term mean climate changes, in affecting organism performance. These ideas are congruent with the current paradigm shift in how we think of the ocean, selective fisheries, and how they relate to organism climate resilience.
- Full Text:
- Authors: Dames, Vivienne Abigail
- Date: 2021
- Subjects: iSimangaliso Wetland Park (South Africa) -- Management , Reef fishes -- South Africa -- KwaZulu-Natal , Baited remote underwater stereo-video systems (stereo-BRUVs) , Marine parks and reserves -- Monitoring -- South Africa -- KwaZulu-Natal , Fish populations -- Measurement
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/171150 , vital:42024
- Description: The persistence of harvested fish populations in the Anthropocene will be determined, above all, by how they respond to the interacting effects of climate change and fisheries exploitation. Predicting how populations will respond to both these threats is essential for any adaptive and sustainable management strategy. The response of fish populations to climate change is underpinned by physiological rates and tolerances, and emerging evidence suggests there may be physiological-based selection in capture fisheries. By quantifying important physiological rates of a model species, the endemic seabream, Chrysoblephus laticeps, across ecologically relevant thermal gradients and from populations subjected to varying intensities of commercial exploitation, this thesis aimed to 1) provide the first physiologically grounded climate resilience assessment for a South African linefish species, and 2) elucidate whether exploitation can drive populations to less physiologically resilient states in response to climate change. To identify physiologically limiting sea temperatures and to determine if exploitation alters physiological trait distributions, an intermittent flow respirometry experiment was used to test the metabolic response of spatially protected and exploited populations of C. laticeps to acute thermal variability. Exploited populations showed reduced metabolic phenotype diversity, fewer high-performance aerobic scope phenotypes, and a significantly lower aerobic scope curve across all test temperatures. Although both populations maintained a relatively high aerobic scope across a wide thermal range, their metabolic rates were compromised when extreme cold events were simulated (8 °C), suggesting that predicted future increases in upwelling frequency and intensity may be the primary limiting factor in a more thermally variable future ocean. The increment widths of annuli in the otoliths of C. laticeps from contemporary and historic collections were measured, as a proxy for the annual growth rate of exploited and protected populations. Hierarchical mixed models were used to partition growth variation within and among individuals and ascribe growth to intrinsic and extrinsic effects. The best model for the protected population indicated that the growth response of C. laticeps was poorer during years characterised by a high cumulative upwelling intensity, and better during years characterised by higher mean autumn sea surface temperatures. The exploited population growth chronology was too short to identify an extrinsic growth driver. The growth results again highlight the role of thermal variability in modulating the response of C. laticeps to its ambient environment and indicate that the predicted increases in upwelling frequency and intensity may constrain future growth rates of this species. A metabolic index (ϕ), representing the ratio of O2 supply to demand at various temperatures and oxygen concentrations, was estimated for exploited and protected populations of C. laticeps and used to predict future distribution responses. There was no difference in the laboratory calibrations of ϕ between populations, and all data was subsequently combined into a single piecewise (12 °C) calibrated ϕ model. To predict the distribution of C. laticeps, ϕ was projected across a high-resolution ocean model of the South African coastal zone, and a species distribution model implemented using the random forest algorithm and C. laticeps occurrence points. The future distribution of C. laticeps was estimated by predicting trained models across ocean model projections up to 2100. The best predictor of C. laticeps’ current distribution was minimum monthly ϕ and future predictions indicated only a slight range contraction on either edge of C. laticeps’ distribution by 2100. In order to provide policy makers, currently developing climate change management frameworks for South Africa’s ocean, with a usable output, the results of all research chapters were combined into a marine spatial model. The spatial model identified areas where C. laticeps is predicted to be resilient to climate change in terms of physiology, growth and distribution responses, which can then be prioritised for adaptation measures, such as spatial protection from exploitation. While these results are specific to C. laticeps, the methodology developed to identify areas of climate resilience has broad applications across taxa. From a global perspective, perhaps the most salient points to consider from this case study are the evidence of selective exploitation on physiological traits and the importance of environmental variability, rather than long-term mean climate changes, in affecting organism performance. These ideas are congruent with the current paradigm shift in how we think of the ocean, selective fisheries, and how they relate to organism climate resilience.
- Full Text:
Language and access in the public healthcare system in South Africa with a particular focus on primary public health facilities in Grahamstown and Cofimvaba in the Eastern Cape
- Authors: Mhlauli, Nonceba
- Date: 2017
- Subjects: Health literacy -- South Africa -- Eastern Cape , Patient education -- South Africa -- Eastern Cape , Communication in medicine -- South Africa -- Eastern Cape , Health literacy -- Social aspects -- South Africa -- Eastern Cape , Poor -- Medical care -- South Africa -- Eastern Cape
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/56692 , vital:26817
- Description: The right to language and the right to healthcare services are human rights which are enshrined in the Constitution of the Republic of South Africa. Section 6 (5) of the Constitution and Section 1.3 (b) and (e) of the Eastern Cape Provincial Language Policy provide protection against unfair discrimination on the grounds of language; while sections 30 and 31 (1) of the Constitution refer to people’s rights in terms of cultural, religious and linguistic participation. Section 27 (a) states that ‘everyone has the right to access to healthcare services’. In accordance with the Constitution, in 2011 the National Department of Health passed a Policy on Language Services. This policy aims to facilitate equitable access to government services and information, as well as respect for language rights as spelled out in the Constitution. The Policy on Language Services further aims to promote multilingualism in the National Department of Health and to allow people to access information in a language of their choice, understand important messages and the language necessary for informed and participatory decision making (Department of Health 2011:1). Given the above policy and Constitutional provisions as far as policy commitment is concerned, the crucial issue remains the implementation of such policy to ensure that the right to access to health and language are realised. The study provides an analysis of the Policy on Language Services 2011 as it relates to language rights and the delivery of health services, focusing on the roll out and implementation process and the public awareness of the policy. This study primarily focuses on the role language plays in accessing public healthcare in primary healthcare facilities in the Grahamstown and Cofimvaba. The study looked at communication between patient and healthcare providers and whether healthcare services were provided in the language of the patient or the language the patient knows best. This study further assessed indications of patients’ comprehension of information such as medical instructions on packaged medicine, comprehension of posters, pamphlets and health education sessions in order to fully participate in the process of their health status. The data of this research was collected from healthcare providers and patients in primary healthcare facilities in Grahamstown and Cofimvaba in the Eastern Cape. The research methods used was in-depth interviews, non-participant observations as well as content analysis such as sign/direction posts, medical labels and information boards. These methods were used to determine whether language plays a role in accessing quality healthcare services in these facilities. The research found that the lack of implementation of language and health policy resulted in the perpetuation of language barriers in the healthcare sector. The study therefore argues that adequate healthcare can only be provided if and when healthcare providers and patients are able to communicate with each other in the language they know best or feel most comfortable in. Thus meaning the implementation of the current Constitutional and policy provisions is crucial to language and access to healthcare services.
- Full Text:
- Authors: Mhlauli, Nonceba
- Date: 2017
- Subjects: Health literacy -- South Africa -- Eastern Cape , Patient education -- South Africa -- Eastern Cape , Communication in medicine -- South Africa -- Eastern Cape , Health literacy -- Social aspects -- South Africa -- Eastern Cape , Poor -- Medical care -- South Africa -- Eastern Cape
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/56692 , vital:26817
- Description: The right to language and the right to healthcare services are human rights which are enshrined in the Constitution of the Republic of South Africa. Section 6 (5) of the Constitution and Section 1.3 (b) and (e) of the Eastern Cape Provincial Language Policy provide protection against unfair discrimination on the grounds of language; while sections 30 and 31 (1) of the Constitution refer to people’s rights in terms of cultural, religious and linguistic participation. Section 27 (a) states that ‘everyone has the right to access to healthcare services’. In accordance with the Constitution, in 2011 the National Department of Health passed a Policy on Language Services. This policy aims to facilitate equitable access to government services and information, as well as respect for language rights as spelled out in the Constitution. The Policy on Language Services further aims to promote multilingualism in the National Department of Health and to allow people to access information in a language of their choice, understand important messages and the language necessary for informed and participatory decision making (Department of Health 2011:1). Given the above policy and Constitutional provisions as far as policy commitment is concerned, the crucial issue remains the implementation of such policy to ensure that the right to access to health and language are realised. The study provides an analysis of the Policy on Language Services 2011 as it relates to language rights and the delivery of health services, focusing on the roll out and implementation process and the public awareness of the policy. This study primarily focuses on the role language plays in accessing public healthcare in primary healthcare facilities in the Grahamstown and Cofimvaba. The study looked at communication between patient and healthcare providers and whether healthcare services were provided in the language of the patient or the language the patient knows best. This study further assessed indications of patients’ comprehension of information such as medical instructions on packaged medicine, comprehension of posters, pamphlets and health education sessions in order to fully participate in the process of their health status. The data of this research was collected from healthcare providers and patients in primary healthcare facilities in Grahamstown and Cofimvaba in the Eastern Cape. The research methods used was in-depth interviews, non-participant observations as well as content analysis such as sign/direction posts, medical labels and information boards. These methods were used to determine whether language plays a role in accessing quality healthcare services in these facilities. The research found that the lack of implementation of language and health policy resulted in the perpetuation of language barriers in the healthcare sector. The study therefore argues that adequate healthcare can only be provided if and when healthcare providers and patients are able to communicate with each other in the language they know best or feel most comfortable in. Thus meaning the implementation of the current Constitutional and policy provisions is crucial to language and access to healthcare services.
- Full Text:
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