The potential conflict of interest associated with the management of Rosa rubiginos L. (Rosehip) in South Africa
- Authors: Westwood, Timothy
- Date: 2021
- Subjects: Invasive plants -- South Africa , Biological invasions -- Economic aspects , Rose hips -- Economic aspects -- South Africa , Roses -- South Africa , Rose culture -- Economic aspects -- South Africa
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/172458 , vital:42204
- Description: Rosa rubiginosa L. is a category 1b invasive plant species in South Africa and must be controlled according to NEM:BA. However, R. rubiginosa has the potential to provide economic benefit in South Africa due to the expanding market for the shrubs fruit, rosehips. The shrub is not permitted to be cultivated in South Africa due to legislation, limiting the economic potential as the rosehips are only able to be collected from wild R. rubiginosa shrubs. In order to expand the rosehip market in South Africa a downgrade or removal of R. rubiginosa from the invasive species list would be required, as wild harvest is limited. This study aims to assess the benefits and cost associated with R. rubiginosa in order to determine whether the legislation should be altered allowing for the cultivation of the shrub in South Africa. Due to the limited literature surrounding R. rubiginosa three different questionnaires and a case study were used in order to assess the benefits and negatives associated with the shrub. Experts in the field of invasion biology were surveyed to bridge the gap in the R. rubiginosa literature. Landowners, where the shrub is abundant, were surveyed to determine the negative impacts of R. rubiginosa. Rosehip companies were surveyed in order to determine the current size and potential of the R. rubiginosa (rosehip) market. The case study looked at how a rosehip company would benefit if R. rubiginosa was allowed to be cultivated in South Africa. The study found R. rubiginosa to have great economic potential and market growth, with very little negative economic impact. The case study showed that one rosehip company would grow from 1500 tons of raw rosehip to 20 000 tons if cultivation was allowed, resulting in a growth in turnover from R57 million to R760 million ($1=R14.8). The findings in the study show that R. rubiginosa does not significantly affect landowners where it is abundant. Therefore, it is suggested that a change to the legislation should be considered allowing for the cultivation of R. rubiginosa should be implemented.
- Full Text:
- Date Issued: 2021
- Authors: Westwood, Timothy
- Date: 2021
- Subjects: Invasive plants -- South Africa , Biological invasions -- Economic aspects , Rose hips -- Economic aspects -- South Africa , Roses -- South Africa , Rose culture -- Economic aspects -- South Africa
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/172458 , vital:42204
- Description: Rosa rubiginosa L. is a category 1b invasive plant species in South Africa and must be controlled according to NEM:BA. However, R. rubiginosa has the potential to provide economic benefit in South Africa due to the expanding market for the shrubs fruit, rosehips. The shrub is not permitted to be cultivated in South Africa due to legislation, limiting the economic potential as the rosehips are only able to be collected from wild R. rubiginosa shrubs. In order to expand the rosehip market in South Africa a downgrade or removal of R. rubiginosa from the invasive species list would be required, as wild harvest is limited. This study aims to assess the benefits and cost associated with R. rubiginosa in order to determine whether the legislation should be altered allowing for the cultivation of the shrub in South Africa. Due to the limited literature surrounding R. rubiginosa three different questionnaires and a case study were used in order to assess the benefits and negatives associated with the shrub. Experts in the field of invasion biology were surveyed to bridge the gap in the R. rubiginosa literature. Landowners, where the shrub is abundant, were surveyed to determine the negative impacts of R. rubiginosa. Rosehip companies were surveyed in order to determine the current size and potential of the R. rubiginosa (rosehip) market. The case study looked at how a rosehip company would benefit if R. rubiginosa was allowed to be cultivated in South Africa. The study found R. rubiginosa to have great economic potential and market growth, with very little negative economic impact. The case study showed that one rosehip company would grow from 1500 tons of raw rosehip to 20 000 tons if cultivation was allowed, resulting in a growth in turnover from R57 million to R760 million ($1=R14.8). The findings in the study show that R. rubiginosa does not significantly affect landowners where it is abundant. Therefore, it is suggested that a change to the legislation should be considered allowing for the cultivation of R. rubiginosa should be implemented.
- Full Text:
- Date Issued: 2021
A mixed methods investigation of students’ attitudes towards statistics and quantitative research methods: a focus on postgraduate psychology students at a South African university
- Authors: Ngantweni, Xolelwa
- Date: 2020
- Subjects: Fetal alcohol spectrum disorders -- South Africa , Statistics , Psychology -- Research , College students -- South Africa -- Attitudes , Psychology -- Research -- South Africa
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/140490 , vital:37894
- Description: Many University programs offer a course in either basic or intermediate statistics as part of the degree requirements prior to graduation (McGrath, Ferns, Greiner, Wanamaker and Brown, 2015). These statistics or quantitative research methods courses are integral in helping students gain vital skills in analysing quantitative data. Research (Schau, Stevens, Dauphinee, and Del Vecchio, 1995) does however indicate that most students have a perfunctory disposition towards these courses. My study sought to particularly investigate attitudes towards statistics and quantitative research methods amongst a sample of 61 postgraduate Psychology students at Rhodes University undertaking a ‘Quantitative Research Methods’ course as part of their degree offering. A mixed methods approach was used to investigate students’ attitudes towards statistics and quantitative research methods. The Survey of Attitudes Toward Statistics (SATS-36) (Schau, 2003) captured student’s attitudes towards statistics using a Likert Scale instrument; whereas detailed qualitative interviews accentuated findings from the SATS-36. Key quantitative findings from the SATS-36 including students’ perceptions of statistics being a difficult course as well as students having a low affect towards statistics are detailed. Key qualitative findings related to why students experience statistics anxiety such as students’ (1) fear of failing statistics, (2) The late introduction of statistics in the Psychology curriculum, and (3) The role of educator/s in alleviating or promoting feelings of statistics anxiety are noted. The significance of these findings as well as the contributions of the study to the teaching and learning of statistics and quantitative research methods courses at Rhodes University are explored, in light of other studies on the topic of statistics anxiety and attitudes towards statistics/ quantitative research methods.
- Full Text:
- Date Issued: 2020
- Authors: Ngantweni, Xolelwa
- Date: 2020
- Subjects: Fetal alcohol spectrum disorders -- South Africa , Statistics , Psychology -- Research , College students -- South Africa -- Attitudes , Psychology -- Research -- South Africa
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/140490 , vital:37894
- Description: Many University programs offer a course in either basic or intermediate statistics as part of the degree requirements prior to graduation (McGrath, Ferns, Greiner, Wanamaker and Brown, 2015). These statistics or quantitative research methods courses are integral in helping students gain vital skills in analysing quantitative data. Research (Schau, Stevens, Dauphinee, and Del Vecchio, 1995) does however indicate that most students have a perfunctory disposition towards these courses. My study sought to particularly investigate attitudes towards statistics and quantitative research methods amongst a sample of 61 postgraduate Psychology students at Rhodes University undertaking a ‘Quantitative Research Methods’ course as part of their degree offering. A mixed methods approach was used to investigate students’ attitudes towards statistics and quantitative research methods. The Survey of Attitudes Toward Statistics (SATS-36) (Schau, 2003) captured student’s attitudes towards statistics using a Likert Scale instrument; whereas detailed qualitative interviews accentuated findings from the SATS-36. Key quantitative findings from the SATS-36 including students’ perceptions of statistics being a difficult course as well as students having a low affect towards statistics are detailed. Key qualitative findings related to why students experience statistics anxiety such as students’ (1) fear of failing statistics, (2) The late introduction of statistics in the Psychology curriculum, and (3) The role of educator/s in alleviating or promoting feelings of statistics anxiety are noted. The significance of these findings as well as the contributions of the study to the teaching and learning of statistics and quantitative research methods courses at Rhodes University are explored, in light of other studies on the topic of statistics anxiety and attitudes towards statistics/ quantitative research methods.
- Full Text:
- Date Issued: 2020
An analysis of South Africa’s food security policy frameworks from a food sovereignty perspective: challenges and implications for genuine long-term food security
- Authors: Hoepfl, Jason
- Date: 2020
- Subjects: Food sovereignty -- South Africa , Food security -- South Africa , Food security -- Government policy -- South Africa , Food security -- Climatic factors -- South Africa , Food policy -- Government policy -- South Africa , Agriculture and state -- South Africa , Food industry and trade -- Government policy -- South Africa
- Language: English
- Type: text , Thesis , Masters , MSocSci
- Identifier: http://hdl.handle.net/10962/162851 , vital:40990
- Description: Food price volatility, ecological shocks and unprecedented levels of hunger and obesity are increasing concerns within food security governance, as is the emergence of food sovereignty in broadening critical discussions around food, water, energy and environmental crises. This thesis analyses this changing terrain in the context of South African policy. It analyses shifts in policymaking and the capability of South Africa’s food security policy frameworks to include food sovereignty principles and in so doing support genuine long-term food security. A shift in policy priorities from household production, trade and income opportunities towards social safety nets and nutritional interventions is identified. This focus is constrained by an inability to affect structural changes within a deeply inequitable food landscape. An emphasis on commercial farming and unwillingness to challenge large agribusiness, value chains and corporate retail has enabled social differentiation in access to food and the country’s colonial land dispensation to continue. Consequently, markets have continued to be antipathetic to the needs of poor producers and consumers in South Africa. To overcome these structural constraints, food security policy needs to be framed within a more radical normative agenda. This is important for challenging inequitable power relations and asserting the social and ecological imperatives of healthy food systems. Food sovereignty has significant potential to support a normative agenda by supporting the multiple farming practices, enterprises and livelihood strategies pursued by poor farmers, the unemployed and working poor whilst preserving sensitive environments for future generations. Determining the future of food security is not the privilege of the few with economic clout or power to govern but the right of all. The incorporation of food sovereignty principles in policymaking is therefore paramount for achieving genuine long-term food security.
- Full Text:
- Date Issued: 2020
- Authors: Hoepfl, Jason
- Date: 2020
- Subjects: Food sovereignty -- South Africa , Food security -- South Africa , Food security -- Government policy -- South Africa , Food security -- Climatic factors -- South Africa , Food policy -- Government policy -- South Africa , Agriculture and state -- South Africa , Food industry and trade -- Government policy -- South Africa
- Language: English
- Type: text , Thesis , Masters , MSocSci
- Identifier: http://hdl.handle.net/10962/162851 , vital:40990
- Description: Food price volatility, ecological shocks and unprecedented levels of hunger and obesity are increasing concerns within food security governance, as is the emergence of food sovereignty in broadening critical discussions around food, water, energy and environmental crises. This thesis analyses this changing terrain in the context of South African policy. It analyses shifts in policymaking and the capability of South Africa’s food security policy frameworks to include food sovereignty principles and in so doing support genuine long-term food security. A shift in policy priorities from household production, trade and income opportunities towards social safety nets and nutritional interventions is identified. This focus is constrained by an inability to affect structural changes within a deeply inequitable food landscape. An emphasis on commercial farming and unwillingness to challenge large agribusiness, value chains and corporate retail has enabled social differentiation in access to food and the country’s colonial land dispensation to continue. Consequently, markets have continued to be antipathetic to the needs of poor producers and consumers in South Africa. To overcome these structural constraints, food security policy needs to be framed within a more radical normative agenda. This is important for challenging inequitable power relations and asserting the social and ecological imperatives of healthy food systems. Food sovereignty has significant potential to support a normative agenda by supporting the multiple farming practices, enterprises and livelihood strategies pursued by poor farmers, the unemployed and working poor whilst preserving sensitive environments for future generations. Determining the future of food security is not the privilege of the few with economic clout or power to govern but the right of all. The incorporation of food sovereignty principles in policymaking is therefore paramount for achieving genuine long-term food security.
- Full Text:
- Date Issued: 2020
The performance and preference of a specialist herbivore, Catorhintha schaffneri (Coreidae), on its polytypic host plant, Pereskia aculeata (Cactaceae)
- Authors: Egbon, Ikponmwosa Nathaniel
- Date: 2019
- Subjects: Insects and biological pest control agents -- South Africa , Pereskia -- Biological control -- South Africa , Cactus -- Biological control -- South Africa , Coreida-- South Africa , Invasive plants -- Biological control -- South Africa , Catorhintha schaffneri
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/68250 , vital:29223
- Description: Plant species moved beyond their natural ranges may be liberated into enemy-free spaces, where they increase resource allocation to fitness, rather than defence against natural enemies, and become invasive as suggested by the Evolution of Increased Competitive Ability (EICA) Hypothesis. Several cacti are notable invaders and are targeted for biological control. The leafy cactus, Pereskia aculeata Miller, introduced into South Africa from South America, has become a target for biological control after becoming invasive. The absence of natural enemies of P. aculeata in the introduced range may be the reason for its invasiveness. This thesis seeks to investigate the role of the evolution of increased competitive ability (enemy release) as the probable driver of P. aculeata’s success, and ascertain how the plant’s intraspecific variation influences the impact, fitness of, and preference by its biological control agent, Catorhintha schaffneri Brailovsky and Garcia (Coreidae), in South Africa. Enemy release and evolution of traits in P. aculeata were examined by quantifying plant growth parameters of fifteen genotypes of P. aculeata from both the native and invaded distribution of the plant. Ten genotypes of P. aculeata were used in testing the effect of agent herbivory (impact and damage) under similar conditions. These studies indicated that most invaded-range genotypes were more vigorous than the native genotypes. Rapid growth may account for the quick access of invasive genotypes of P. aculeata to tree canopies. Catorhintha schaffneri damage varied between genotypes but differences in the damage and impact from the agent could not be explained by whether the plant originated in the introduced or native distribution. In sum, while the growth of the invasive genotypes largely conforms to the EICA hypothesis, the impact of C. schaffneri did not support the hypothesis. The influence of host variation in P. aculeata on the fitness of C. schaffneri within the context of local adaptation to plant genotypes from different localities was tested using agent survival, stage-specific and total developmental time, and the extent of damage to ten host genotypes. Maw’s Host Suitability Index (HIS) and Dobie’s Susceptibility Index (DSI) showed the preference by and performance of C. schaffneri on the different genotypes of the plant. Catorhintha schaffneri survived to the adult stage on 70% of genotypes tested. Evidence consistent with the assumption that C. schaffneri would be fitter on the native genotypes than the invasive genotypes due to local adaptation was not found. In addition, there was no evidence in support of fitter agents on the invasive genotypes than on the native genotypes as proposed by EICA hypothesis. Catorhintha schaffneri developed equally well on the invasive genotypes of P. aculeata as on the native genotypes. To establish whether host variation would affect diet selection by C. schaffneri, both nymphs and adults were examined in paired-choice and multiple-choice trials. The nymphs and adults chose their hosts regardless of host genotype differences. The agent may be good at selecting good succulent shoots from bad shoots, but is incapable of distinguishing a good host genotype from a poorer one. This thesis shows, therefore, that P. aculeata and its array of genotypes in South Africa could be effectively controlled by C. schaffneri, as it has the potential to suitably utilise and impact the different genotypes of the weed in South Africa with neither any demonstrable preference nor local adaptation for the native genotypes. Consequently, the use of C. schaffneri, as a biological control agent in the weed biological control programme of P. aculeata remains promising, as the agent is insensitive to the intraspecific variation of the invasive host plants.
- Full Text:
- Date Issued: 2019
- Authors: Egbon, Ikponmwosa Nathaniel
- Date: 2019
- Subjects: Insects and biological pest control agents -- South Africa , Pereskia -- Biological control -- South Africa , Cactus -- Biological control -- South Africa , Coreida-- South Africa , Invasive plants -- Biological control -- South Africa , Catorhintha schaffneri
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/68250 , vital:29223
- Description: Plant species moved beyond their natural ranges may be liberated into enemy-free spaces, where they increase resource allocation to fitness, rather than defence against natural enemies, and become invasive as suggested by the Evolution of Increased Competitive Ability (EICA) Hypothesis. Several cacti are notable invaders and are targeted for biological control. The leafy cactus, Pereskia aculeata Miller, introduced into South Africa from South America, has become a target for biological control after becoming invasive. The absence of natural enemies of P. aculeata in the introduced range may be the reason for its invasiveness. This thesis seeks to investigate the role of the evolution of increased competitive ability (enemy release) as the probable driver of P. aculeata’s success, and ascertain how the plant’s intraspecific variation influences the impact, fitness of, and preference by its biological control agent, Catorhintha schaffneri Brailovsky and Garcia (Coreidae), in South Africa. Enemy release and evolution of traits in P. aculeata were examined by quantifying plant growth parameters of fifteen genotypes of P. aculeata from both the native and invaded distribution of the plant. Ten genotypes of P. aculeata were used in testing the effect of agent herbivory (impact and damage) under similar conditions. These studies indicated that most invaded-range genotypes were more vigorous than the native genotypes. Rapid growth may account for the quick access of invasive genotypes of P. aculeata to tree canopies. Catorhintha schaffneri damage varied between genotypes but differences in the damage and impact from the agent could not be explained by whether the plant originated in the introduced or native distribution. In sum, while the growth of the invasive genotypes largely conforms to the EICA hypothesis, the impact of C. schaffneri did not support the hypothesis. The influence of host variation in P. aculeata on the fitness of C. schaffneri within the context of local adaptation to plant genotypes from different localities was tested using agent survival, stage-specific and total developmental time, and the extent of damage to ten host genotypes. Maw’s Host Suitability Index (HIS) and Dobie’s Susceptibility Index (DSI) showed the preference by and performance of C. schaffneri on the different genotypes of the plant. Catorhintha schaffneri survived to the adult stage on 70% of genotypes tested. Evidence consistent with the assumption that C. schaffneri would be fitter on the native genotypes than the invasive genotypes due to local adaptation was not found. In addition, there was no evidence in support of fitter agents on the invasive genotypes than on the native genotypes as proposed by EICA hypothesis. Catorhintha schaffneri developed equally well on the invasive genotypes of P. aculeata as on the native genotypes. To establish whether host variation would affect diet selection by C. schaffneri, both nymphs and adults were examined in paired-choice and multiple-choice trials. The nymphs and adults chose their hosts regardless of host genotype differences. The agent may be good at selecting good succulent shoots from bad shoots, but is incapable of distinguishing a good host genotype from a poorer one. This thesis shows, therefore, that P. aculeata and its array of genotypes in South Africa could be effectively controlled by C. schaffneri, as it has the potential to suitably utilise and impact the different genotypes of the weed in South Africa with neither any demonstrable preference nor local adaptation for the native genotypes. Consequently, the use of C. schaffneri, as a biological control agent in the weed biological control programme of P. aculeata remains promising, as the agent is insensitive to the intraspecific variation of the invasive host plants.
- Full Text:
- Date Issued: 2019
Essence of home: relevance of home and the assertion of place amongst Centane migrants, South Africa
- Authors: Njwambe, Avela Thandisiwe
- Date: 2018
- Subjects: Rural-urban migration -- South Africa , Migrant labor -- South Africa , Immigrants -- South Africa -- Social conditions , Immigrants -- South Africa -- Eastern Cape , Immigrants -- South Africa -- Homelands , Homelands (South Africa) , Home -- Psychological aspects
- Language: English
- Type: text , Thesis , Masters , MSocSc
- Identifier: http://hdl.handle.net/10962/51866 , vital:26136
- Description: South Africa is currently experiencing ever-increasing rural-urban migration with many citizens from the former homeland areas migrating to cities to seek employment. Despite long-term residence in urban areas, many township dwellers do not consider these places to be home. Research into circular migration patterns reveal the lifelong relationships that migrants (amagoduka) have with their family home (ekhayeni). This study aimed to explore this relationship, looking in particular at the meanings imbued in the locality of home. In addition, the role of natural landscapes and social components in constructing meanings and attachments to ekhayeni for Xhosa-speaking migrants in Cape Town townships, who have family linkages to rural villages in the Transkei, was also explored. The study found that the landscape of home remains central to migrants’ cultural identity, belonging and well-being. Childhood experiences in nature, and cultural and recreational activities that continue to take rural inhabitants into these landscapes, remain key to this relationship. The rural area, as a geographical entity embodied with social and cultural/spiritual components continued to supply and satisfy many human needs for migrants, which were seen as crucial for psychological, mental and spiritual well-being.
- Full Text:
- Date Issued: 2018
Essence of home: relevance of home and the assertion of place amongst Centane migrants, South Africa
- Authors: Njwambe, Avela Thandisiwe
- Date: 2018
- Subjects: Rural-urban migration -- South Africa , Migrant labor -- South Africa , Immigrants -- South Africa -- Social conditions , Immigrants -- South Africa -- Eastern Cape , Immigrants -- South Africa -- Homelands , Homelands (South Africa) , Home -- Psychological aspects
- Language: English
- Type: text , Thesis , Masters , MSocSc
- Identifier: http://hdl.handle.net/10962/51866 , vital:26136
- Description: South Africa is currently experiencing ever-increasing rural-urban migration with many citizens from the former homeland areas migrating to cities to seek employment. Despite long-term residence in urban areas, many township dwellers do not consider these places to be home. Research into circular migration patterns reveal the lifelong relationships that migrants (amagoduka) have with their family home (ekhayeni). This study aimed to explore this relationship, looking in particular at the meanings imbued in the locality of home. In addition, the role of natural landscapes and social components in constructing meanings and attachments to ekhayeni for Xhosa-speaking migrants in Cape Town townships, who have family linkages to rural villages in the Transkei, was also explored. The study found that the landscape of home remains central to migrants’ cultural identity, belonging and well-being. Childhood experiences in nature, and cultural and recreational activities that continue to take rural inhabitants into these landscapes, remain key to this relationship. The rural area, as a geographical entity embodied with social and cultural/spiritual components continued to supply and satisfy many human needs for migrants, which were seen as crucial for psychological, mental and spiritual well-being.
- Full Text:
- Date Issued: 2018
The response of microalgal biomass and community composition to the chemical and physical dynamics of two Eastern Cape estuaries
- Authors: Cotiyane, Phumlile L
- Date: 2017
- Subjects: Estuarine plants -- South Africa -- Eastern Cape , Estuarine ecology -- South Africa -- Eastern Cape , Phytoplankton -- South Africa -- Eastern Cape , Algal blooms -- South Africa -- Eastern Cape , Algal blooms -- Monitoring-- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/4999 , vital:20751
- Description: Water quality characteristics of estuaries are influenced by both natural and anthropogenic activities. Estuaries situated in coastal urban areas are exposed to more perturbations than those in rural settings. This study determined the drivers of phytoplankton biomass and community composition in two Eastern Cape estuaries and evaluated the anthropogenic activities that influence the overall health of each estuary. The estuaries were sampled in summer and winter (2014, 2015). The water quality of the estuaries was determined by measuring the variability in physico-chemical parameters (salinity, temperature, dissolved oxygen and pH), nutrients, phytoplankton biomass and composition and faecal bacteria. Results show that both Mngazana and Nahoon are well oxygenated (~ 6.0 mg l-¹) and are saline systems (~ 35 ppt) due to low freshwater inputs into both estuaries. Mngazana Estuary exhibited low nutrient inputs along the length of the estuary including Creeks 1 and 2 with low chlorophyll a (4.0 ± 0.2 µg Chl-a r¹) being recorded during this study while Nahoon Estuary had an overall chlorophyll a of 3.5 ± 0.3 µg Chl-a r¹. The two estuaries were dominated by flagellates with phytoplankton blooms recorded seasonally. Possible eutrophic conditions were evident along the upper reaches of Nahoon indicated by nutrient accumulation and by the presence of cyanobacteria. This also this reflected the possible anthropogenic nutrient inputs originating from the Nahoon catchment despite the low freshwater inflow. The presence of faecal bacteria counts along both estuaries indicates the need for further investigation into the source of faecal contamination. The use of nutrient analyses and phytoplankton composition during this study enabled a clear description of the water characteristics of the investigated estuaries. Furthermore, the need for the adherence to freshwater flow requirements of estuaries to limit the dominance of marine waters was clearly illustrated. Urban runoff due to impervious surfaces increases nutrient inputs into estuaries while rural use of estuarine waters introduces contaminants into the system; coupled with low freshwater inputs and eutrophic conditions, the deterioration of estuarine water quality over time demonstrates the need for effective monitoring of these systems.
- Full Text:
- Date Issued: 2017
- Authors: Cotiyane, Phumlile L
- Date: 2017
- Subjects: Estuarine plants -- South Africa -- Eastern Cape , Estuarine ecology -- South Africa -- Eastern Cape , Phytoplankton -- South Africa -- Eastern Cape , Algal blooms -- South Africa -- Eastern Cape , Algal blooms -- Monitoring-- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/4999 , vital:20751
- Description: Water quality characteristics of estuaries are influenced by both natural and anthropogenic activities. Estuaries situated in coastal urban areas are exposed to more perturbations than those in rural settings. This study determined the drivers of phytoplankton biomass and community composition in two Eastern Cape estuaries and evaluated the anthropogenic activities that influence the overall health of each estuary. The estuaries were sampled in summer and winter (2014, 2015). The water quality of the estuaries was determined by measuring the variability in physico-chemical parameters (salinity, temperature, dissolved oxygen and pH), nutrients, phytoplankton biomass and composition and faecal bacteria. Results show that both Mngazana and Nahoon are well oxygenated (~ 6.0 mg l-¹) and are saline systems (~ 35 ppt) due to low freshwater inputs into both estuaries. Mngazana Estuary exhibited low nutrient inputs along the length of the estuary including Creeks 1 and 2 with low chlorophyll a (4.0 ± 0.2 µg Chl-a r¹) being recorded during this study while Nahoon Estuary had an overall chlorophyll a of 3.5 ± 0.3 µg Chl-a r¹. The two estuaries were dominated by flagellates with phytoplankton blooms recorded seasonally. Possible eutrophic conditions were evident along the upper reaches of Nahoon indicated by nutrient accumulation and by the presence of cyanobacteria. This also this reflected the possible anthropogenic nutrient inputs originating from the Nahoon catchment despite the low freshwater inflow. The presence of faecal bacteria counts along both estuaries indicates the need for further investigation into the source of faecal contamination. The use of nutrient analyses and phytoplankton composition during this study enabled a clear description of the water characteristics of the investigated estuaries. Furthermore, the need for the adherence to freshwater flow requirements of estuaries to limit the dominance of marine waters was clearly illustrated. Urban runoff due to impervious surfaces increases nutrient inputs into estuaries while rural use of estuarine waters introduces contaminants into the system; coupled with low freshwater inputs and eutrophic conditions, the deterioration of estuarine water quality over time demonstrates the need for effective monitoring of these systems.
- Full Text:
- Date Issued: 2017
The location of meaning in the postmodernist literary text: a reading of Mark Z. Danielewski's House of Leaves and related material
- Authors: Jeffery, Thomas Carnegie
- Date: 2004
- Subjects: Danielewski, Mark Z. House of leaves , Danielewski, Mark Z. Criticism and interpretation , Horror tales , English literature -- Criticism, Textual , Literature, Modern -- History and criticism , Postmodernism (Literature)
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2196 , http://hdl.handle.net/10962/d1002238
- Description: In House of Leaves, Mark Z. Danielewski has produced a text which epitomises the traits and concerns of postmodernist literature. Through his attention to aspects such as metafiction, intertextuality and parody, Danielewski develops a narrative structure which is best understood as a literary labyrinth. It is a structure intended to reflect the social conditions of the twenty-first century and comment on the experience of people living at this time. Some of the meaning-making strategies within the book’s labyrinthine structure are thus discussed in detail in order to demonstrate the relevance and importance of House of Leaves as social commentary. House of Leaves is an exemplary postmodernist text, but it is also one that seeks to guide the reader beyond the intellectual impasse of the postmodernist paradigm toward a renewed ethical and political engagement with the world. One of the most important goals of both Danielewski’s novel and this thesis is to attempt to redefine the postmodernist perspective in such a way as to insist on the necessity of what I call a new realism. This is founded upon an awareness of the pervasiveness of the self-perpetuating ideology of capitalism, even in the perspective of postmodernism (which purports to subvert all authoritative ideologies). Playing a crucial role in perpetuating the status quo of capitalism is the growth of entertainment culture, which works to sideline crucial political issues by replacing information with infotainment. The result is an intensification of the processes of commodification. Such an intensification, it is argued, may be countered by a radical scepticism which draws upon the methods and insights of contemporary science.
- Full Text:
- Date Issued: 2004
- Authors: Jeffery, Thomas Carnegie
- Date: 2004
- Subjects: Danielewski, Mark Z. House of leaves , Danielewski, Mark Z. Criticism and interpretation , Horror tales , English literature -- Criticism, Textual , Literature, Modern -- History and criticism , Postmodernism (Literature)
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2196 , http://hdl.handle.net/10962/d1002238
- Description: In House of Leaves, Mark Z. Danielewski has produced a text which epitomises the traits and concerns of postmodernist literature. Through his attention to aspects such as metafiction, intertextuality and parody, Danielewski develops a narrative structure which is best understood as a literary labyrinth. It is a structure intended to reflect the social conditions of the twenty-first century and comment on the experience of people living at this time. Some of the meaning-making strategies within the book’s labyrinthine structure are thus discussed in detail in order to demonstrate the relevance and importance of House of Leaves as social commentary. House of Leaves is an exemplary postmodernist text, but it is also one that seeks to guide the reader beyond the intellectual impasse of the postmodernist paradigm toward a renewed ethical and political engagement with the world. One of the most important goals of both Danielewski’s novel and this thesis is to attempt to redefine the postmodernist perspective in such a way as to insist on the necessity of what I call a new realism. This is founded upon an awareness of the pervasiveness of the self-perpetuating ideology of capitalism, even in the perspective of postmodernism (which purports to subvert all authoritative ideologies). Playing a crucial role in perpetuating the status quo of capitalism is the growth of entertainment culture, which works to sideline crucial political issues by replacing information with infotainment. The result is an intensification of the processes of commodification. Such an intensification, it is argued, may be countered by a radical scepticism which draws upon the methods and insights of contemporary science.
- Full Text:
- Date Issued: 2004
The concurrent jurisdiction of the Labour Court and the High Court
- Authors: Wagener, Pieter Cornelius
- Date: 2002
- Subjects: South Africa. High Court , South Africa. Labour Court , Exclusive and concurrent legislative powers -- South Africa , Law, Interpretation and construction
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:11051 , http://hdl.handle.net/10948/286 , South Africa. High Court , South Africa. Labour Court , Exclusive and concurrent legislative powers -- South Africa , Law, Interpretation and construction
- Description: An overview is given of the difficulties surrounding the concurrent jurisdiction of the Labour Court and High Court The main categories of the jurisdictional dispute are identified and systemised. The main branches are those of statutory overlap and interpretation of statutes. Statutory overlap concerns matters remaining from the industrial court era, urgent applications, delict and law of contract. Statutory interpretation mainly involves the interpretation of provisions in the Bill of Rights of the Constitution. An overview of the principles of jurisdiction with respect to the different courts, as well as a brief historical review of the development of such jurisdiction is given. Particular attention is given to the role of fundamental rights in the Constitution. Broad principles are identified whereby the difficulties may be addressed.
- Full Text:
- Date Issued: 2002
- Authors: Wagener, Pieter Cornelius
- Date: 2002
- Subjects: South Africa. High Court , South Africa. Labour Court , Exclusive and concurrent legislative powers -- South Africa , Law, Interpretation and construction
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:11051 , http://hdl.handle.net/10948/286 , South Africa. High Court , South Africa. Labour Court , Exclusive and concurrent legislative powers -- South Africa , Law, Interpretation and construction
- Description: An overview is given of the difficulties surrounding the concurrent jurisdiction of the Labour Court and High Court The main categories of the jurisdictional dispute are identified and systemised. The main branches are those of statutory overlap and interpretation of statutes. Statutory overlap concerns matters remaining from the industrial court era, urgent applications, delict and law of contract. Statutory interpretation mainly involves the interpretation of provisions in the Bill of Rights of the Constitution. An overview of the principles of jurisdiction with respect to the different courts, as well as a brief historical review of the development of such jurisdiction is given. Particular attention is given to the role of fundamental rights in the Constitution. Broad principles are identified whereby the difficulties may be addressed.
- Full Text:
- Date Issued: 2002
Water quality and faunal studies in the Umzimvubu catchment, Eastern Cape, with particular emphasis on species as indicators of environmental change
- Madikizela, B R, Dye, Arthur H, O'Keeffe, Jay H
- Authors: Madikizela, B R , Dye, Arthur H , O'Keeffe, Jay H
- Date: 2001
- Subjects: To be catalogued
- Language: English
- Type: text , report
- Identifier: http://hdl.handle.net/10962/437730 , vital:73405 , ISBN 1 86845 705 2 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/716-1-01.pdf
- Description: The primary aim of the project was to establish a water quality database and an in-ventory of aquatic fauna for the Umzimvubu River and its four main tributaries. The identification of species that are sensitive to environmental threats and that might be used as future indicators of environmental change, was the secondary aim. The results are outlined in Chapters 2, 3 and 4, while Chapter 5 reflects on conclusions and recommendations for further research. Based on the water quality data in Chapter 2 and macro-invertebrate scores (SASS4 and ASPT) in Chapter 3, the quality of water is good, suggesting that the catchment is not significantly degraded, ex-cept threats by soil erosion (Fig.2.15) leading to very high TSS loads (see Appendices 1- 3).
- Full Text:
- Date Issued: 2001
- Authors: Madikizela, B R , Dye, Arthur H , O'Keeffe, Jay H
- Date: 2001
- Subjects: To be catalogued
- Language: English
- Type: text , report
- Identifier: http://hdl.handle.net/10962/437730 , vital:73405 , ISBN 1 86845 705 2 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/716-1-01.pdf
- Description: The primary aim of the project was to establish a water quality database and an in-ventory of aquatic fauna for the Umzimvubu River and its four main tributaries. The identification of species that are sensitive to environmental threats and that might be used as future indicators of environmental change, was the secondary aim. The results are outlined in Chapters 2, 3 and 4, while Chapter 5 reflects on conclusions and recommendations for further research. Based on the water quality data in Chapter 2 and macro-invertebrate scores (SASS4 and ASPT) in Chapter 3, the quality of water is good, suggesting that the catchment is not significantly degraded, ex-cept threats by soil erosion (Fig.2.15) leading to very high TSS loads (see Appendices 1- 3).
- Full Text:
- Date Issued: 2001
Media reach and reception in development communication: the case of the Rural Industries Innovation Centre in Botswana
- Authors: Maleke, Jackson Mogopodi
- Date: 1998
- Subjects: Rural Industries Innovation Centre (Kanye, Botswana) , Communication in rural development , Mass media in community development
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3455 , http://hdl.handle.net/10962/d1002909 , Rural Industries Innovation Centre (Kanye, Botswana) , Communication in rural development , Mass media in community development
- Description: The study was conducted in Phitshane-Molopo in Botswana. Phitshane-Molopo is located about 115 kilometers south of the main village of Kanye in which the Rural Industries Innovation Centre operates. The study constitutes the first attempt at evaluating audience reach and reception of the RIIC media messages. In this study, a sample of 50 representatives of households (the rationale is covered in chapter 1) was taken, for which a questionnaire was administered, including conducting in-depth interviews with key informants. The study found that RIlC media are not reaching the audience in keeping with the corporate goals and assumptions on the basis of which the communication strategy was established. The audience has claimed that the print media relayed to them through the extension officer channel do not reach them. The study also found that the audience possessed adequate literacy skills and the majority of them could read materials produced in Setswana. Only a few individuals preferred media text produced in the English language. The study therefore deplores RIIC's proclivity towards producing its media texts only in the English language. This has tended to marginalise members of the audience who cannot read in English. It is thus hoped that this study would provide a learning experience for RIIC to consider producing its communication media in relation to the needs of the audience. The study also found that the impact of the RIIC radio programme is very poor, with only a low of 2% of the sample population having listened to this programme. The problem stems from the poor Radio Botswana transmission system. The audience said that for the larger part of the day, they can't get Radio Botswana on air. As a result, they have shifted their interest to the South African radio stations such as Radio Tswana and Radio Mmabatho, which are constantly on air. The study concludes that the RIIC communication strategy is failing in the study area because the paradigm in which it is located is somewhat flawed, as a result of which it does not effectively impact upon reach and reception. At the core of this failure rate are implementation problems and the lack of evaluation that would have picked up the - problems earlier, for which solutions would have been found. Consequently, th~$tudy recommends the need to explore the suitability and effectiveness of the indigenous media for possible syncretization with conventional media as recommended in the need based integrative model (Nwosu and Megwa: 1993). Indigenous media are ideally suited to rural communication needs because they are consistent with the socio-cultural expectations of the audience. RIIC therefore stands to benefit from these media because the bulk of its audience resides in rural areas.
- Full Text:
- Date Issued: 1998
- Authors: Maleke, Jackson Mogopodi
- Date: 1998
- Subjects: Rural Industries Innovation Centre (Kanye, Botswana) , Communication in rural development , Mass media in community development
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3455 , http://hdl.handle.net/10962/d1002909 , Rural Industries Innovation Centre (Kanye, Botswana) , Communication in rural development , Mass media in community development
- Description: The study was conducted in Phitshane-Molopo in Botswana. Phitshane-Molopo is located about 115 kilometers south of the main village of Kanye in which the Rural Industries Innovation Centre operates. The study constitutes the first attempt at evaluating audience reach and reception of the RIIC media messages. In this study, a sample of 50 representatives of households (the rationale is covered in chapter 1) was taken, for which a questionnaire was administered, including conducting in-depth interviews with key informants. The study found that RIlC media are not reaching the audience in keeping with the corporate goals and assumptions on the basis of which the communication strategy was established. The audience has claimed that the print media relayed to them through the extension officer channel do not reach them. The study also found that the audience possessed adequate literacy skills and the majority of them could read materials produced in Setswana. Only a few individuals preferred media text produced in the English language. The study therefore deplores RIIC's proclivity towards producing its media texts only in the English language. This has tended to marginalise members of the audience who cannot read in English. It is thus hoped that this study would provide a learning experience for RIIC to consider producing its communication media in relation to the needs of the audience. The study also found that the impact of the RIIC radio programme is very poor, with only a low of 2% of the sample population having listened to this programme. The problem stems from the poor Radio Botswana transmission system. The audience said that for the larger part of the day, they can't get Radio Botswana on air. As a result, they have shifted their interest to the South African radio stations such as Radio Tswana and Radio Mmabatho, which are constantly on air. The study concludes that the RIIC communication strategy is failing in the study area because the paradigm in which it is located is somewhat flawed, as a result of which it does not effectively impact upon reach and reception. At the core of this failure rate are implementation problems and the lack of evaluation that would have picked up the - problems earlier, for which solutions would have been found. Consequently, th~$tudy recommends the need to explore the suitability and effectiveness of the indigenous media for possible syncretization with conventional media as recommended in the need based integrative model (Nwosu and Megwa: 1993). Indigenous media are ideally suited to rural communication needs because they are consistent with the socio-cultural expectations of the audience. RIIC therefore stands to benefit from these media because the bulk of its audience resides in rural areas.
- Full Text:
- Date Issued: 1998
South African panorama: the novels of Daphne Rooke
- Authors: Coetzee, Paulette June
- Date: 1998
- Subjects: Rooke, Daphne, 1914- -- Criticism and interpretation
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2222 , http://hdl.handle.net/10962/d1002265 , Rooke, Daphne, 1914- -- Criticism and interpretation
- Description: This thesis covers Daphne Rooke's eight published "South African" novels: A Grove of Fever Trees, Mittee, Ratoons, Wizards' Country, A Lover for Estelle, The Greyling, Diamond Jo, and Margaretha de la Porte. It supports the recent revival of critical interest in Rooke, and argues for the continuing relevance of her work in post-apartheid South Africa. This study also broadens the scope of recent Rooke research by including lesser known works like The Greyling and Margaretha de la Porte in its analysis. Recent criticism has focused on Rooke's unusual blend of romance and realism. The first three chapters concentrate more on "realism", emphasising the depth and extent of Rooke's engagement with serious social issues. The novels are examined in terms of their handling of the themes of class (chapter one), race (chapter two) and gender (chapter three). The concluding chapter shifts in focus to "romance" and examines the question of generic_identity -- touching on Rooke's gothic, magical realist and "popular" qualities -within a consideration of the particular "South African-ness" of her work.
- Full Text:
- Date Issued: 1998
- Authors: Coetzee, Paulette June
- Date: 1998
- Subjects: Rooke, Daphne, 1914- -- Criticism and interpretation
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2222 , http://hdl.handle.net/10962/d1002265 , Rooke, Daphne, 1914- -- Criticism and interpretation
- Description: This thesis covers Daphne Rooke's eight published "South African" novels: A Grove of Fever Trees, Mittee, Ratoons, Wizards' Country, A Lover for Estelle, The Greyling, Diamond Jo, and Margaretha de la Porte. It supports the recent revival of critical interest in Rooke, and argues for the continuing relevance of her work in post-apartheid South Africa. This study also broadens the scope of recent Rooke research by including lesser known works like The Greyling and Margaretha de la Porte in its analysis. Recent criticism has focused on Rooke's unusual blend of romance and realism. The first three chapters concentrate more on "realism", emphasising the depth and extent of Rooke's engagement with serious social issues. The novels are examined in terms of their handling of the themes of class (chapter one), race (chapter two) and gender (chapter three). The concluding chapter shifts in focus to "romance" and examines the question of generic_identity -- touching on Rooke's gothic, magical realist and "popular" qualities -within a consideration of the particular "South African-ness" of her work.
- Full Text:
- Date Issued: 1998
The Role of the Missionaries in Conquest
- Date: 1986
- Subjects: South Africa -- History -- 20th century , Government, Resistance to -- South Africa
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10948/37293 , vital:34154 , Bulk File 7
- Description: This is one of many individual publications put out by the New Unity Movement History Series and is a republication of a book by Nosipho Majeke.
- Full Text: false
- Date Issued: 1986
- Date: 1986
- Subjects: South Africa -- History -- 20th century , Government, Resistance to -- South Africa
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10948/37293 , vital:34154 , Bulk File 7
- Description: This is one of many individual publications put out by the New Unity Movement History Series and is a republication of a book by Nosipho Majeke.
- Full Text: false
- Date Issued: 1986
A geographical analysis of farming in East Griqualand
- Authors: Leslie, Kathryn Ann
- Date: 1985
- Subjects: Agriculture -- Griqualand East (South Africa) , Rural development -- Griqualand East (South Africa) , Agricultural deography -- Griqualand East (South Africa) , Geography -- Methodology , Infrastructure (Economics) -- Griqualand East (South Africa)
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:4860 , http://hdl.handle.net/10962/d1005857 , Agriculture -- Griqualand East (South Africa) , Rural development -- Griqualand East (South Africa) , Agricultural deography -- Griqualand East (South Africa) , Geography -- Methodology , Infrastructure (Economics) -- Griqualand East (South Africa)
- Description: From Preface: The study focusses on spatial aspects of farming and particularly how di stance from marketing centres influences farming activity. However, not all aspects of farming activity could be given close attention due to the limited time and funds available and it was decided to isolate two aspects of farming activity for detailed study, namely, farm size and intensity. Other variables, such as land-use, are looked at in relation to the two main variables. Although East Griqualand is the general area selected for study, for practical purposes it was decided to select areas within East Griqualand for an in-depth study. As the study focusses on the influence of distance from marketing centres on farming activity, it was decided to select marketing centres in East Griqualand around which farming takes place. There are six of these centres in East Griqualand, that is, Kokstad, Matatiele, Cedarville, Franklin, Swartberg and New Amalfi. Two marketing centres, Cedarville and Swartberg, were selected and the farms served by these centres became the two sub-areas in which the research was conducted. The selection of the marketing centres and the justification for this selection is discussed in Chapter Four. A problem arose when calculating the distance from the farming unit to the marketing centre where a single set of books is kept even though the farming unit does not consist of one contiguous area. It was, however, found that all farmers conduct farming operations from a central farm, usually that on which they reside and on which farming implements and other farming requirements are stored. The distance was therefore calculated from the farm gate of the farm from which farming operations are controlled. The general study area is show in Figure 6. However, it was difficult to delimit the exact study area on the map as many of the farm boundaries were imperfectly known by farmers and were considered confidential information by local agricultural officials. The two sub-areas consist of the areas surrounding the marketing centres of Cedarville and Swartberg respectively. As a study of this nature has not previously been conducted in East Griqualand, it was decided that the study should constitute a pilot survey. As such, the study is a preliminary survey aimed at identifying general trends of the relationship between distance to marketing centres, farm size and intensity of fanning in the selected areas. The study could therefore be used to provide pointers for further research and act as a basis for a more comprehensive study of the same nature in East Griqualand.
- Full Text:
- Date Issued: 1985
- Authors: Leslie, Kathryn Ann
- Date: 1985
- Subjects: Agriculture -- Griqualand East (South Africa) , Rural development -- Griqualand East (South Africa) , Agricultural deography -- Griqualand East (South Africa) , Geography -- Methodology , Infrastructure (Economics) -- Griqualand East (South Africa)
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:4860 , http://hdl.handle.net/10962/d1005857 , Agriculture -- Griqualand East (South Africa) , Rural development -- Griqualand East (South Africa) , Agricultural deography -- Griqualand East (South Africa) , Geography -- Methodology , Infrastructure (Economics) -- Griqualand East (South Africa)
- Description: From Preface: The study focusses on spatial aspects of farming and particularly how di stance from marketing centres influences farming activity. However, not all aspects of farming activity could be given close attention due to the limited time and funds available and it was decided to isolate two aspects of farming activity for detailed study, namely, farm size and intensity. Other variables, such as land-use, are looked at in relation to the two main variables. Although East Griqualand is the general area selected for study, for practical purposes it was decided to select areas within East Griqualand for an in-depth study. As the study focusses on the influence of distance from marketing centres on farming activity, it was decided to select marketing centres in East Griqualand around which farming takes place. There are six of these centres in East Griqualand, that is, Kokstad, Matatiele, Cedarville, Franklin, Swartberg and New Amalfi. Two marketing centres, Cedarville and Swartberg, were selected and the farms served by these centres became the two sub-areas in which the research was conducted. The selection of the marketing centres and the justification for this selection is discussed in Chapter Four. A problem arose when calculating the distance from the farming unit to the marketing centre where a single set of books is kept even though the farming unit does not consist of one contiguous area. It was, however, found that all farmers conduct farming operations from a central farm, usually that on which they reside and on which farming implements and other farming requirements are stored. The distance was therefore calculated from the farm gate of the farm from which farming operations are controlled. The general study area is show in Figure 6. However, it was difficult to delimit the exact study area on the map as many of the farm boundaries were imperfectly known by farmers and were considered confidential information by local agricultural officials. The two sub-areas consist of the areas surrounding the marketing centres of Cedarville and Swartberg respectively. As a study of this nature has not previously been conducted in East Griqualand, it was decided that the study should constitute a pilot survey. As such, the study is a preliminary survey aimed at identifying general trends of the relationship between distance to marketing centres, farm size and intensity of fanning in the selected areas. The study could therefore be used to provide pointers for further research and act as a basis for a more comprehensive study of the same nature in East Griqualand.
- Full Text:
- Date Issued: 1985
Feeding ecology of the cichlid fish Sarotherodon Mossambicus in Lake Sibaya, KwaZulu
- Authors: Bowen, Stephen H
- Date: 1977
- Subjects: Cichlids -- Ecology , Fishes -- Ecology -- South Africa -- KwaZulu-Natal -- Sibaya, Lake
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5837 , http://hdl.handle.net/10962/d1009688 , Cichlids -- Ecology , Fishes -- Ecology -- South Africa -- KwaZulu-Natal -- Sibaya, Lake
- Description: The feeding of the cichlid fish Sarotherodon mossambicus in Lake Sibaya, KwaZulu, was studied in relation to various biotic and abiotic features of the l ake environment from January, 1973 to July, 1975. The primary goal of the study was to determine the cause of stunting and poor condition of adults in this population. Juvenile and adult S. mossambicus feed on a mixture of detritus, bacteria and diatoms that occurs as a flocculent layer on sand substrates throughout the lake. Concentrated gastric acid, commonly at pH values of 1.5 and lower, lyses diatoms and bacteria which are subsequently digested in the intestine. This is the first report of digestion of bacteria by a fish, and the nutritional significance of the finding is discussed. Juveniles feed predominantly on shallow sand terraces found along the margin of much of the lake, while adults usually feed in offshore waters at depths of 3 m and greater. Benthic floc from feeding areas of juveniles and adults have similar concentrations of organic matter, total carbohydrate, soluble carbohydrate and calories, but differ markedly in respect to diatom and protein concentration. Diatom concentrations are generally high in terrace floc but are consistently low in floc from deep water. Protein concentration of benthic floc decreases with increasing depth from 0 - 5 m. Partial correlation analysis shows that protein and diatom concentrations have no correlation independent. of their common relationship to depth, and the evidence implicates detrital bacteria as the primary source of protein in benthic floc. Probable causes of the observed distributions of diatoms and protein are discussed. The protein content of benthic floc profoundly influences its nutritional value. A comparison with available data on animal nutrition shows that the ratio of digestible protein to digestible energy in floc in the shallows is high enough that this food resource would be expected to support good growth, but the ratio for deep water floc is so low that it would be expected to result in conspicuous malnutrition. Thus, inadequate dietary protein is identified as the principal cause of stunting and poor condition of adult S· mossambicus in Lake Sibaya; It is argued that the ratio of digestible protein to digestible calories can be expected to determine the food value of particulate organic matter that includes amorphous detritus in other ecosystems. Despite stunting and poor condition of adults, S. mossambicus are abundant in Lake Sibaya. The precocious breeding of this population is discussed as an adaptation that allows it to maximize reproductive output given the limited resources available to adults. Juvenile S. mossambicus perform daily movements from deep water onto the terraces where they feed and then back into deep water. During periods of relatively low lake level when terrace waters were usually less than 1.5 m deep (1-73 to 1-74), juveniles were present on the terrace throughout daylight hours. At relatively high lake levels (7-74 to 8-75), juveniles were present on the terraces for only about five hours following sunset. Periods of heavy wave action interrupt feeding activity and result in reduced numbers of fish in terrace waters. The possible roles of predator avoidance and temperature in determination of daily feeding behavior are discussed. Daily energy assimilation by juveniles, estimated by a field technique, is approximately 115 cal per g fish dry weight.
- Full Text:
- Date Issued: 1977
- Authors: Bowen, Stephen H
- Date: 1977
- Subjects: Cichlids -- Ecology , Fishes -- Ecology -- South Africa -- KwaZulu-Natal -- Sibaya, Lake
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5837 , http://hdl.handle.net/10962/d1009688 , Cichlids -- Ecology , Fishes -- Ecology -- South Africa -- KwaZulu-Natal -- Sibaya, Lake
- Description: The feeding of the cichlid fish Sarotherodon mossambicus in Lake Sibaya, KwaZulu, was studied in relation to various biotic and abiotic features of the l ake environment from January, 1973 to July, 1975. The primary goal of the study was to determine the cause of stunting and poor condition of adults in this population. Juvenile and adult S. mossambicus feed on a mixture of detritus, bacteria and diatoms that occurs as a flocculent layer on sand substrates throughout the lake. Concentrated gastric acid, commonly at pH values of 1.5 and lower, lyses diatoms and bacteria which are subsequently digested in the intestine. This is the first report of digestion of bacteria by a fish, and the nutritional significance of the finding is discussed. Juveniles feed predominantly on shallow sand terraces found along the margin of much of the lake, while adults usually feed in offshore waters at depths of 3 m and greater. Benthic floc from feeding areas of juveniles and adults have similar concentrations of organic matter, total carbohydrate, soluble carbohydrate and calories, but differ markedly in respect to diatom and protein concentration. Diatom concentrations are generally high in terrace floc but are consistently low in floc from deep water. Protein concentration of benthic floc decreases with increasing depth from 0 - 5 m. Partial correlation analysis shows that protein and diatom concentrations have no correlation independent. of their common relationship to depth, and the evidence implicates detrital bacteria as the primary source of protein in benthic floc. Probable causes of the observed distributions of diatoms and protein are discussed. The protein content of benthic floc profoundly influences its nutritional value. A comparison with available data on animal nutrition shows that the ratio of digestible protein to digestible energy in floc in the shallows is high enough that this food resource would be expected to support good growth, but the ratio for deep water floc is so low that it would be expected to result in conspicuous malnutrition. Thus, inadequate dietary protein is identified as the principal cause of stunting and poor condition of adult S· mossambicus in Lake Sibaya; It is argued that the ratio of digestible protein to digestible calories can be expected to determine the food value of particulate organic matter that includes amorphous detritus in other ecosystems. Despite stunting and poor condition of adults, S. mossambicus are abundant in Lake Sibaya. The precocious breeding of this population is discussed as an adaptation that allows it to maximize reproductive output given the limited resources available to adults. Juvenile S. mossambicus perform daily movements from deep water onto the terraces where they feed and then back into deep water. During periods of relatively low lake level when terrace waters were usually less than 1.5 m deep (1-73 to 1-74), juveniles were present on the terrace throughout daylight hours. At relatively high lake levels (7-74 to 8-75), juveniles were present on the terraces for only about five hours following sunset. Periods of heavy wave action interrupt feeding activity and result in reduced numbers of fish in terrace waters. The possible roles of predator avoidance and temperature in determination of daily feeding behavior are discussed. Daily energy assimilation by juveniles, estimated by a field technique, is approximately 115 cal per g fish dry weight.
- Full Text:
- Date Issued: 1977
Trade unions, community organisation and politics: a local case study on the East Rand
- Authors: Holdt, K von
- Date: 19--?
- Subjects: Labour unions -- South Africa , Labour unions -- Political activity -- South Africa , Community development -- South Africa
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/73269 , vital:30171
- Description: This dissertation sets out as a challenge to two trends in the analysis of the trade union movement. The first trend implies that there is no fundamental difference in political strategy between the Federation of South African Trade Unions (FOSATU) and the Congress of South African Trade Unions (COSATU) which was formed in 1985 and included amongst others all the FOSATU affiliates. Swilling for instance writes that the unions established in the 1970s "shunned distinctions between economic and political issues and stridently challenged state policies" (Swilling, 1987: 2). Maree too implies that the involvement of the industrial unions in community and political struggles in the mid-1980s was not incompatible with their earlier position (1987: 10).
- Full Text:
- Date Issued: 19--?
- Authors: Holdt, K von
- Date: 19--?
- Subjects: Labour unions -- South Africa , Labour unions -- Political activity -- South Africa , Community development -- South Africa
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/73269 , vital:30171
- Description: This dissertation sets out as a challenge to two trends in the analysis of the trade union movement. The first trend implies that there is no fundamental difference in political strategy between the Federation of South African Trade Unions (FOSATU) and the Congress of South African Trade Unions (COSATU) which was formed in 1985 and included amongst others all the FOSATU affiliates. Swilling for instance writes that the unions established in the 1970s "shunned distinctions between economic and political issues and stridently challenged state policies" (Swilling, 1987: 2). Maree too implies that the involvement of the industrial unions in community and political struggles in the mid-1980s was not incompatible with their earlier position (1987: 10).
- Full Text:
- Date Issued: 19--?
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