The role of microhabitats within mangroves: an invertebrate and fish larval perspective
- Authors: Vorsatz, Lyle Dennis
- Date: 2020
- Subjects: Mangrove ecology -- South Africa , Mangrove forests -- South Africa , Niche (Ecology) , Rhizophora mucronata , Acanthaceae , Rhizophoraceae , Fishes -- Larvae -- South Africa , Aquatic ecology -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/167644 , vital:41499
- Description: Microhabitats provided through structural complexity are central for the diversity, productivity, connectivity and niche differentiation within and among ecosystems. Mangrove forests afford juvenile fish and invertebrates with nursery and recruitment habitats, facilitated by the fine scale configuration of their specialised root systems. Although the importance of mangroves for resident and transient juveniles is well recognised, the roles that mangrove microhabitats play for larvae is not yet comprehensively understood. This study aimed to determine how microhabitats with varying degrees of complexity influence the composition, abundance and distribution of larval communities that inhabit mangrove forests and the physiological responses of larvae to acute temperature variations in relation to ontogenetic stage and microenvironment exposure. Two relatively pristine study sites were selected to represent a warm temperate and subtropical mangrove system in the Eastern Cape and KwaZulu-Natal on the east coast of South Africa, respectively. The differences in complexity among the root systems of Rhizophora mucronata, Avicennia marina and Bruguiera gymnorhiza were assessed using 3D scanning and the computed 3D models were then analysed using four complexity metrics. Results indicated that A. marina is the most complex in terms of surface-volume ratio, R. mucronata has the most interstitial space among its roots and B. gymnorhiza and R. mucronata differ in their fractal dimensions. Larvae collected in each microhabitat at each site using light traps showed that, despite temperature and salinity homogeneity across microenvironments, spatio-temporal differences occurred in both fish and invertebrate assemblages. This trend suggests that microhabitat structural complexity exerts an influence on larval community composition by acting as a microscape of available habitat, which ensures ecological linkages within and among the mangrove forest and adjacent ecosystems. In addition, the oxygen consumption rates of mangrove-associated brachyuran larvae varied according to mangrove microhabitat, whereby larvae collected at less complex environments had the highest metabolic rates at increased temperatures. Moreover, ontogenetic shifts in physiology were prevalent as older brachyuran larvae were more eurythermal than earlier stages, suggesting that thermally stressful events will have a greater impact on recently spawned larvae. Overall, the interstitial spaces within individual root systems are the most important complexity measure, as utilisation of these mangrove microhabitats is scale-dependent, and larvae will most likely occupy spaces inaccessible to large predators. Likewise, microscale variation in the environmental conditions and ontogenetic stage of brachyuran larvae within the mangrove microscape, can amplify the physiological responses to rapid temperature variations. Results suggest that early stage larvae are the most vulnerable to mass-mortality, and if thermally stressful events increase in frequency, duration and magnitude, the larval supply for the successful recruitment into adult populations could be under threat. Through linking how mangrove microhabitat complexity influences larvae in terms of community metrics and physiology, this study paves the way for further advancement of our understanding of how microscale processes emerge into meso- and macroscale patterns and influence the stability and functioning of highly productive ecosystems.
- Full Text:
- Date Issued: 2020
- Authors: Vorsatz, Lyle Dennis
- Date: 2020
- Subjects: Mangrove ecology -- South Africa , Mangrove forests -- South Africa , Niche (Ecology) , Rhizophora mucronata , Acanthaceae , Rhizophoraceae , Fishes -- Larvae -- South Africa , Aquatic ecology -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/167644 , vital:41499
- Description: Microhabitats provided through structural complexity are central for the diversity, productivity, connectivity and niche differentiation within and among ecosystems. Mangrove forests afford juvenile fish and invertebrates with nursery and recruitment habitats, facilitated by the fine scale configuration of their specialised root systems. Although the importance of mangroves for resident and transient juveniles is well recognised, the roles that mangrove microhabitats play for larvae is not yet comprehensively understood. This study aimed to determine how microhabitats with varying degrees of complexity influence the composition, abundance and distribution of larval communities that inhabit mangrove forests and the physiological responses of larvae to acute temperature variations in relation to ontogenetic stage and microenvironment exposure. Two relatively pristine study sites were selected to represent a warm temperate and subtropical mangrove system in the Eastern Cape and KwaZulu-Natal on the east coast of South Africa, respectively. The differences in complexity among the root systems of Rhizophora mucronata, Avicennia marina and Bruguiera gymnorhiza were assessed using 3D scanning and the computed 3D models were then analysed using four complexity metrics. Results indicated that A. marina is the most complex in terms of surface-volume ratio, R. mucronata has the most interstitial space among its roots and B. gymnorhiza and R. mucronata differ in their fractal dimensions. Larvae collected in each microhabitat at each site using light traps showed that, despite temperature and salinity homogeneity across microenvironments, spatio-temporal differences occurred in both fish and invertebrate assemblages. This trend suggests that microhabitat structural complexity exerts an influence on larval community composition by acting as a microscape of available habitat, which ensures ecological linkages within and among the mangrove forest and adjacent ecosystems. In addition, the oxygen consumption rates of mangrove-associated brachyuran larvae varied according to mangrove microhabitat, whereby larvae collected at less complex environments had the highest metabolic rates at increased temperatures. Moreover, ontogenetic shifts in physiology were prevalent as older brachyuran larvae were more eurythermal than earlier stages, suggesting that thermally stressful events will have a greater impact on recently spawned larvae. Overall, the interstitial spaces within individual root systems are the most important complexity measure, as utilisation of these mangrove microhabitats is scale-dependent, and larvae will most likely occupy spaces inaccessible to large predators. Likewise, microscale variation in the environmental conditions and ontogenetic stage of brachyuran larvae within the mangrove microscape, can amplify the physiological responses to rapid temperature variations. Results suggest that early stage larvae are the most vulnerable to mass-mortality, and if thermally stressful events increase in frequency, duration and magnitude, the larval supply for the successful recruitment into adult populations could be under threat. Through linking how mangrove microhabitat complexity influences larvae in terms of community metrics and physiology, this study paves the way for further advancement of our understanding of how microscale processes emerge into meso- and macroscale patterns and influence the stability and functioning of highly productive ecosystems.
- Full Text:
- Date Issued: 2020
Implementing the annual national assessment at an ordinary public primary school in the Eastern Cape: a case study analysis
- Authors: Lascelles, Philippa Anne
- Date: 2017
- Subjects: Educational tests and measurements -- South Africa , Educational tests and measurements -- South Africa -- Case studies , Education, Elementary -- South Africa , Elementary schools -- South Africa -- Makhanda
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/7713 , vital:21288
- Description: This empirical study describes in rich detail five teachers’ perceptions of the Annual National Assessment [ANA] at one level of the school system (Grade Three of the Foundation Phase [FP]) at an ordinary public primary school in an urban area of the Eastern Cape. Secondly, the study described the process of preparing for, implementing and assessing the 2014 ANA at the selected school. In order to generate insights for a deep understanding of how teachers perceive, prepare for and implement the ANA, the challenges that arise, and how the ANA is impacting on curriculum and pedagogy, an interpretive qualitative research approach and case study method were adopted. The researcher, a participant observer operating from an insider position, used ethnographic techniques to describe, document and analyse teachers’ perceptions and experiences of implementing the 2014 ANA tests in a specific context (one school) and at one level of the school system (Grade 3). Data gathered through observations, semi-structured interviews and document analysis were coded and analysed in order to identify emerging themes. These are compared to trends and developments in contemporary literature on educational assessment. The findings revealed that while the teachers were compliant and efficient in their implementation and administration of the ANA, they have a narrow perception of the ANA as a summative assessment serving systemic purposes. There was little, if any, evidence of them using the ANA for the formative assessment purposes intended by policy. As a result, opportunities for using the ANA to enhance teaching and learning were lost. The study illuminated the roles and responsibilities of the teachers, the school management team and Eastern Cape [EC] Department of Education [DoE] in the ANA preparation and implementation process, and the need for strengthening the support provided by the EC DoE. Although context specific, the study sheds light on how Grade 3 teachers in an ordinary public school perceive and implement the ANA. The insights afforded and lessons that can be learned from this case study may be relevant to other Foundation Phase school contexts.
- Full Text:
- Date Issued: 2017
- Authors: Lascelles, Philippa Anne
- Date: 2017
- Subjects: Educational tests and measurements -- South Africa , Educational tests and measurements -- South Africa -- Case studies , Education, Elementary -- South Africa , Elementary schools -- South Africa -- Makhanda
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/7713 , vital:21288
- Description: This empirical study describes in rich detail five teachers’ perceptions of the Annual National Assessment [ANA] at one level of the school system (Grade Three of the Foundation Phase [FP]) at an ordinary public primary school in an urban area of the Eastern Cape. Secondly, the study described the process of preparing for, implementing and assessing the 2014 ANA at the selected school. In order to generate insights for a deep understanding of how teachers perceive, prepare for and implement the ANA, the challenges that arise, and how the ANA is impacting on curriculum and pedagogy, an interpretive qualitative research approach and case study method were adopted. The researcher, a participant observer operating from an insider position, used ethnographic techniques to describe, document and analyse teachers’ perceptions and experiences of implementing the 2014 ANA tests in a specific context (one school) and at one level of the school system (Grade 3). Data gathered through observations, semi-structured interviews and document analysis were coded and analysed in order to identify emerging themes. These are compared to trends and developments in contemporary literature on educational assessment. The findings revealed that while the teachers were compliant and efficient in their implementation and administration of the ANA, they have a narrow perception of the ANA as a summative assessment serving systemic purposes. There was little, if any, evidence of them using the ANA for the formative assessment purposes intended by policy. As a result, opportunities for using the ANA to enhance teaching and learning were lost. The study illuminated the roles and responsibilities of the teachers, the school management team and Eastern Cape [EC] Department of Education [DoE] in the ANA preparation and implementation process, and the need for strengthening the support provided by the EC DoE. Although context specific, the study sheds light on how Grade 3 teachers in an ordinary public school perceive and implement the ANA. The insights afforded and lessons that can be learned from this case study may be relevant to other Foundation Phase school contexts.
- Full Text:
- Date Issued: 2017
Coping with xenophobia : Senegalese migrants in Port Elizabeth
- Authors: Barbali, Silvana Claudia
- Date: 2009
- Subjects: Xenophobia -- South Africa -- Port Elizabeth Migrant labor -- South Africa -- Port Elizabeth Immigrants -- South Africa -- Port Elizabeth Foreign workers -- South Africa -- Port Elizabeth Aliens -- South Africa -- Social conditions Immigrants -- Africa -- Social conditions
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2102 , http://hdl.handle.net/10962/d1002665
- Description: This thesis seeks to investigate Senegalese migrants' experiences of xenophobia in South Africa. It explores prevailing theories used to explain the phenomenon of xenophobia and uses data collected via anthropological fieldwork to support arguments made. It is argued that a culture of migration in Senegal and the significance of migration as a rite of passage in Senegalese masculinity assists migrants to orientate themselves in host countries, and influences the way Senegalese are „received‟ by South Africans. In addition, Senegalese Islam (Sufi Orientation), which organises its members into brotherhoods, assists in the social integration of Senegalese men in Port Elizabeth. The men belong to the Mouride Brotherhood and the thesis shows how membership to the brotherhood provides a strong network of support for migrant men without resulting in the enclaving of the men in the broader social and economic context of Port Elizabeth. This has important implications for the individual and collective migration experience of Senegalese and influences the men's creation of meaning in their experiences as migrants. The thesis makes use of the concept of transnationalism to analyse the complex and multifaceted nature of transnational migration, arguing that migration experiences are influenced by a range of transnational factors and is deeply culturally influenced. The research suggests that migration experts and government departments in South Africa should take these complexities into account when formulating new programmes and policies for migrants.
- Full Text:
- Date Issued: 2009
- Authors: Barbali, Silvana Claudia
- Date: 2009
- Subjects: Xenophobia -- South Africa -- Port Elizabeth Migrant labor -- South Africa -- Port Elizabeth Immigrants -- South Africa -- Port Elizabeth Foreign workers -- South Africa -- Port Elizabeth Aliens -- South Africa -- Social conditions Immigrants -- Africa -- Social conditions
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2102 , http://hdl.handle.net/10962/d1002665
- Description: This thesis seeks to investigate Senegalese migrants' experiences of xenophobia in South Africa. It explores prevailing theories used to explain the phenomenon of xenophobia and uses data collected via anthropological fieldwork to support arguments made. It is argued that a culture of migration in Senegal and the significance of migration as a rite of passage in Senegalese masculinity assists migrants to orientate themselves in host countries, and influences the way Senegalese are „received‟ by South Africans. In addition, Senegalese Islam (Sufi Orientation), which organises its members into brotherhoods, assists in the social integration of Senegalese men in Port Elizabeth. The men belong to the Mouride Brotherhood and the thesis shows how membership to the brotherhood provides a strong network of support for migrant men without resulting in the enclaving of the men in the broader social and economic context of Port Elizabeth. This has important implications for the individual and collective migration experience of Senegalese and influences the men's creation of meaning in their experiences as migrants. The thesis makes use of the concept of transnationalism to analyse the complex and multifaceted nature of transnational migration, arguing that migration experiences are influenced by a range of transnational factors and is deeply culturally influenced. The research suggests that migration experts and government departments in South Africa should take these complexities into account when formulating new programmes and policies for migrants.
- Full Text:
- Date Issued: 2009
Psychiatric problems in the primary health care context: a study in the Border-Kei area
- Authors: Cook, Jacqueline
- Date: 1996
- Subjects: Primary health care -- South Africa , Mental health services -- South Africa , Black people -- Mental health -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2954 , http://hdl.handle.net/10962/d1002463 , Primary health care -- South Africa , Mental health services -- South Africa , Black people -- Mental health -- South Africa
- Description: A clinic survey was undertaken to investigate the nature of psychiatric problems experienced by the primary health care (PHC) patient population in the Bisho-King William's Town area of the Eastern Cape Region. The study took as its point of departure research findings which attest to the high rate of psychiatric distress amongst this population group in different parts of the world and ohservations regarding the form of presentation in terms of physical complaints. Hypotheses posited relationships between psychiatric problems experienced by patients attending PHC clinics in the study area and four types of variables, namely; somatic complaints, socio-demographic characteristics, patterns of health service utilisation and patient satisfaction with health services. Using a quasi-experimental descriptive approach, a two-stage screening procedure sorted the patient sample into three groups on the basis of the degree of psychiatric symptomatology experienced. The triangulation of the results of between-groups analyses with case materials recorded during psychiatric interviewing provided for an ethnographic account of the cultural experience of distress in the study area. The screening process used standard instruments, the Self-Reporting Questionnaire (SRQ) in the first stage and the Present State Examination (PSE) in the second stage. A pilot study was conducted prior to the fieldwork for the main study. Using the SRQ, thirteen psychiatric paticnts and 31 general PHC patients were sampled for the pilot study and 148 PHC patients were sampled for the main study. Using the PSE, 11 and 57 PSE interviews were conducted in the pilot and main studies respectively. Between-groups analyses used chi-square and F-statistics to investigate possible associations with identified patient correlates (P<0.5). These were socio-demographic, utilisation and satisfaction variables, measured by a separate face-valid self-response instrument compiled for the purposes of this study. Psychiatric symptomatology was found to be statistically significantly related to age, marital status and educational level. Further, patients experiencing more psychiatric symptomatology reported significantly more illnesses requiring treatment, longer consultation periods and a greater number of sick bed days. No statistically significant relationships were found between psychiatric symptomatology and number of children, number of failures at school, amount of treatment utilised, number of consultations, or patient satisfaction with services. Descriptive analyses of symptom and syndrome profiles found certain somatic complaints to be particularly prevalent amongst the patient sample. These include headaches and various tension pains, decreased energy levels and digestive problems. Qualitative analysis of interview data found that many somatic and psychiatric problems experienced constitute culturally defined and meaningful experiences, especially 'umbilini' (or nerves), 'ufufunyana' (a possession state), and accusations of witchcraft. Interpretation of complaints from the local traditional healing perspective, revealed a more complex mode of communication between patients and the health delivery system than may be accounted for in terms of a simple biomedical model. The interpretive analysis in the study showed that some forms of presentation incorporating somatic symptoms, such as 'nerves' may he viewed as help seeking behaviour of the socially unempowered. Implications of the results are discussed in relation to the need for improved identification and management of psychiatric distress at PHC level facilitated by a better developed referral network and closer interaction between biomedical and anthropological perspectives.
- Full Text:
- Date Issued: 1996
- Authors: Cook, Jacqueline
- Date: 1996
- Subjects: Primary health care -- South Africa , Mental health services -- South Africa , Black people -- Mental health -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2954 , http://hdl.handle.net/10962/d1002463 , Primary health care -- South Africa , Mental health services -- South Africa , Black people -- Mental health -- South Africa
- Description: A clinic survey was undertaken to investigate the nature of psychiatric problems experienced by the primary health care (PHC) patient population in the Bisho-King William's Town area of the Eastern Cape Region. The study took as its point of departure research findings which attest to the high rate of psychiatric distress amongst this population group in different parts of the world and ohservations regarding the form of presentation in terms of physical complaints. Hypotheses posited relationships between psychiatric problems experienced by patients attending PHC clinics in the study area and four types of variables, namely; somatic complaints, socio-demographic characteristics, patterns of health service utilisation and patient satisfaction with health services. Using a quasi-experimental descriptive approach, a two-stage screening procedure sorted the patient sample into three groups on the basis of the degree of psychiatric symptomatology experienced. The triangulation of the results of between-groups analyses with case materials recorded during psychiatric interviewing provided for an ethnographic account of the cultural experience of distress in the study area. The screening process used standard instruments, the Self-Reporting Questionnaire (SRQ) in the first stage and the Present State Examination (PSE) in the second stage. A pilot study was conducted prior to the fieldwork for the main study. Using the SRQ, thirteen psychiatric paticnts and 31 general PHC patients were sampled for the pilot study and 148 PHC patients were sampled for the main study. Using the PSE, 11 and 57 PSE interviews were conducted in the pilot and main studies respectively. Between-groups analyses used chi-square and F-statistics to investigate possible associations with identified patient correlates (P<0.5). These were socio-demographic, utilisation and satisfaction variables, measured by a separate face-valid self-response instrument compiled for the purposes of this study. Psychiatric symptomatology was found to be statistically significantly related to age, marital status and educational level. Further, patients experiencing more psychiatric symptomatology reported significantly more illnesses requiring treatment, longer consultation periods and a greater number of sick bed days. No statistically significant relationships were found between psychiatric symptomatology and number of children, number of failures at school, amount of treatment utilised, number of consultations, or patient satisfaction with services. Descriptive analyses of symptom and syndrome profiles found certain somatic complaints to be particularly prevalent amongst the patient sample. These include headaches and various tension pains, decreased energy levels and digestive problems. Qualitative analysis of interview data found that many somatic and psychiatric problems experienced constitute culturally defined and meaningful experiences, especially 'umbilini' (or nerves), 'ufufunyana' (a possession state), and accusations of witchcraft. Interpretation of complaints from the local traditional healing perspective, revealed a more complex mode of communication between patients and the health delivery system than may be accounted for in terms of a simple biomedical model. The interpretive analysis in the study showed that some forms of presentation incorporating somatic symptoms, such as 'nerves' may he viewed as help seeking behaviour of the socially unempowered. Implications of the results are discussed in relation to the need for improved identification and management of psychiatric distress at PHC level facilitated by a better developed referral network and closer interaction between biomedical and anthropological perspectives.
- Full Text:
- Date Issued: 1996
The geology of a portion of north-western Albany
- Authors: Wright, Alexander Ross
- Date: 1969
- Subjects: Geology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5068 , http://hdl.handle.net/10962/d1013440
- Description: [Introduction] During 1965 the author, in looking for a project for a thesis to be submitted for the degree of Master of Science in Geology, decided to map a suitable region in order to gain experience in geological field work. The exact nature of the region itself was of no great importance, but since this study was to be conducted through Rhodes University, it was decided that an area, as near to Grahamstown as possible, would be the most suitable. With this in view, the geologist in charge of the Grahamstown Office of the Geological Survey was invited to suggest an area suitable for study, and if possible, to obtain financial assistance. He indicated the region which has been mapped and which will eventually form part of the proposed sheet 143. It is immediately adjacent to, and to the west of the 1:125,000 sheet 136 of Grahamstown completed by Mountain in 1940.
- Full Text:
- Date Issued: 1969
- Authors: Wright, Alexander Ross
- Date: 1969
- Subjects: Geology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5068 , http://hdl.handle.net/10962/d1013440
- Description: [Introduction] During 1965 the author, in looking for a project for a thesis to be submitted for the degree of Master of Science in Geology, decided to map a suitable region in order to gain experience in geological field work. The exact nature of the region itself was of no great importance, but since this study was to be conducted through Rhodes University, it was decided that an area, as near to Grahamstown as possible, would be the most suitable. With this in view, the geologist in charge of the Grahamstown Office of the Geological Survey was invited to suggest an area suitable for study, and if possible, to obtain financial assistance. He indicated the region which has been mapped and which will eventually form part of the proposed sheet 143. It is immediately adjacent to, and to the west of the 1:125,000 sheet 136 of Grahamstown completed by Mountain in 1940.
- Full Text:
- Date Issued: 1969
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