The role of the deep spawning grounds in chokka squid (Loligo reynaudi d'orbigny, 1845) recruitment
- Authors: Downey, Nicola Jean
- Date: 2014
- Subjects: Squids -- Spawning -- South Africa Squids -- Effect of temperature on -- South Africa Squids -- Embryos -- South Africa Squids -- South Africa -- Geographical distribution Loligo -- Research -- South Africa Loligo fisheries -- South Africa Recruitment (Population biology) -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5359 , http://hdl.handle.net/10962/d1011867
- Description: It was previously thought that the South African chokka squid Loligo reynaudi is exclusively an inshore, shallow water spawner. Although spawning mostly within shallow bays (<60 m) the presence of squid eggs in trawls at depths up to 130 m indicates this species frequently makes use of deeper spawning areas on the mid-shelf. The extent of mid-shelf spawning (referred to as deep spawning) and the contribution to recruitment has yet to be assessed. Studies have shown mid-shelf bottom temperature to vary considerably from those inshore, suggesting chokka squid spawn in two very different oceanographic environments. Considering these apparent environmental differences, what leads to the mid-shelf environment becoming a suitable spawning habitat? Does a suitable benthic habitat, required for the attachment of egg pods, occur on the mid-shelf? These questions are not only important for determining the extent of deep spawning, but also to the understanding of factors “driving” deep spawning. The fate of deep spawned hatchlings is another unknown. It has been proposed that the main chokka squid inshore spawning grounds are positioned to exploit the net westward currents on the Eastern Agulhas Bank, i.e. paralarvae would be transported west from the hatching site to the cold ridge, an area of high primary and secondary productivity on the Central Agulhas Bank. This concept has come to be known as the Western Transport Hypothesis. Lagrangian ROMS-IBMs (regional ocean model system – individual-based model) predict the net westward transport of paralarvae from both the inshore and deep spawning grounds, to the cold ridge. These simulations were used to investigate the transport of hatchlings to the cold ridge feeding grounds before the exhaustion of yolk reserves. The fate of paralarvae on reaching the feeding grounds has not yet been investigated. This work has contributed new knowledge to our understanding of deep spawning and its role in recruitment. Specific aims of this study were to (1) determine the extent, range and importance of the deep spawning grounds relative to those inshore; (2) investigate the deep spawning ground habitat (Agulhas Bank mid-shelf) morphology and oceanographic environment; (3) determine the transport and survival of deep spawned hatchlings; and (4) investigate the origin and distribution of chokka squid paralarvae on the Agulhas Bank. The extent, depth range and importance of the deep spawning grounds, relative to those inshore was assessed using 23 years of demersal trawl survey data. Data for both the west and south coasts of South Africa were examined for egg capsules. No spawning was found on the west coast. Data showed that chokka squid preferred the Eastern Agulhas Bank for spawning. Spawning occurred not only inshore but also on the mid-shelf extending to depths of 270 m near the shelf edge. The majority of deep spawned eggs however, were found in the depth range 71-130 m. Squid egg density markedly decreased beyond 70 m, suggesting delineation between the inshore and deep spawning grounds. Total egg biomass calculations for depths shallower and deeper than 70 m indicated the coastal area to be strongly favoured, i.e. 82 vs. 18%. These results contest the commonly accepted notion that chokka squid is an inshore spawner and redefine the spawning grounds to extend across the shelf. Apart from an initial study investigating bottom temperature on the mid-shelf, very little is known about the deep spawning habitat. St Francis Bay, a commonly used spawning location, was chosen as a demonstration area for further study. The deep spawning grounds (71-130 m) were mapped and benthic habitat described from underwater video footage. A study investigating cross-shelf bottom conditions was undertaken off Thys Bay. CTD data were used to compare seasonal bottom temperature and oxygen on the St Francis Bay inshore and deep spawning grounds. Squid movement between the two spawning habitats was assessed using filament tagging. Predation and fishing pressure across the spawning grounds was reviewed. The mid-shelf benthic habitat was found to be similar to that inshore and available for spawning. Despite the generally colder bottom temperatures on the mid-shelf, this study showed that bottom temperature in deeper waters can at times be warmer than inshore. Although mid-shelf warming events lasted from a few hours to a number of days, they resulted in similar conditions to those on the inshore spawning grounds. It is likely these events act to expand or shift spawning habitat. The movement of squid between the two spawning habitats makes it possible for them to seek patches of warm bottom water with appropiate substrate. This suggests they are spawning habitat opportunists. Predation and fishing pressure appear to be higher on the inshore spawning grounds. It is feasible that this also forces spawners to seek out more favourable habitat offshore. An individual-based model was used to predict the fate of mid-shelf and inshore hatched paralarvae. Within the model, both the highly productive cold ridge and inshore spawning grounds were considered feeding or nursery areas. Paralarvae were released from six inshore and six deep spawning sites, spanning the coast between Port Alfred and Knysna. All paralarvae not reaching the feeding areas before the exhaustion of yolk-reserves (≤5 days), not retained within the feeding grounds (≥14 days), and not retained on the Agulhas Bank after exiting the feeding grounds were considered lost. This work illustrated the dependence of paralarval transport success on both spawning location and time of hatching, as established in earlier studies. The current IBM has expanded on initial work, emphasizing the importance of the cold ridge and inshore spawning grounds as nursery areas for deep and inshore spawned paralarvae, respectively. This work has highlighted the complex interactions between processes influencing recruitment variability for chokka squid. Possible relationships between periods of highest recruitment success and spawning peaks were identified for both spawning habitats. Based on the likely autumn increase in deep spawning off Tsitsikamma, and the beneficial currents during this period, it can be concluded deep spawning may at times contribute significantly to recruitment. This is particularly true for years where the cold ridge persists into winter. Data on chokka squid paralarval distribution are scarce. Paralarval distribution and abundance, in relation to Agulhas Bank oceanography, was investigated using bongo caught paralarvae and corresponding oceanographic data. Individual-based models (IBMs) were used to predict the origin or spawning site of the wild caught paralarvae, with reference to inshore versus deep spawning. Although failing to predict realistic points of origin, this study provided evidence to support a number of scenarios previously assumed to influence chokka squid recruitment. First is the possible influence of coastal upwelling on the retention, and hence spatial distribution, of paralarvae on the inshore spawning grounds. The second factor thought to impact recruitment is the loss of paralarvae from the Agulhas Bank ecosystem. This study confirmed the removal of paralarvae from the Eastern Agulhas Bank due to Agulhas Current boundary phenomena and resultant offshelf leakage. In addition, data suggested that the formation of the cold ridge could enhance retention on the Central Agulhas Bank, and so prevent offshelf leakage from the Central and Western Agulhas Bank. A synthesis of the main conclusions is presented. Implications of the findings and directions for future research are discussed.
- Full Text:
- Authors: Downey, Nicola Jean
- Date: 2014
- Subjects: Squids -- Spawning -- South Africa Squids -- Effect of temperature on -- South Africa Squids -- Embryos -- South Africa Squids -- South Africa -- Geographical distribution Loligo -- Research -- South Africa Loligo fisheries -- South Africa Recruitment (Population biology) -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5359 , http://hdl.handle.net/10962/d1011867
- Description: It was previously thought that the South African chokka squid Loligo reynaudi is exclusively an inshore, shallow water spawner. Although spawning mostly within shallow bays (<60 m) the presence of squid eggs in trawls at depths up to 130 m indicates this species frequently makes use of deeper spawning areas on the mid-shelf. The extent of mid-shelf spawning (referred to as deep spawning) and the contribution to recruitment has yet to be assessed. Studies have shown mid-shelf bottom temperature to vary considerably from those inshore, suggesting chokka squid spawn in two very different oceanographic environments. Considering these apparent environmental differences, what leads to the mid-shelf environment becoming a suitable spawning habitat? Does a suitable benthic habitat, required for the attachment of egg pods, occur on the mid-shelf? These questions are not only important for determining the extent of deep spawning, but also to the understanding of factors “driving” deep spawning. The fate of deep spawned hatchlings is another unknown. It has been proposed that the main chokka squid inshore spawning grounds are positioned to exploit the net westward currents on the Eastern Agulhas Bank, i.e. paralarvae would be transported west from the hatching site to the cold ridge, an area of high primary and secondary productivity on the Central Agulhas Bank. This concept has come to be known as the Western Transport Hypothesis. Lagrangian ROMS-IBMs (regional ocean model system – individual-based model) predict the net westward transport of paralarvae from both the inshore and deep spawning grounds, to the cold ridge. These simulations were used to investigate the transport of hatchlings to the cold ridge feeding grounds before the exhaustion of yolk reserves. The fate of paralarvae on reaching the feeding grounds has not yet been investigated. This work has contributed new knowledge to our understanding of deep spawning and its role in recruitment. Specific aims of this study were to (1) determine the extent, range and importance of the deep spawning grounds relative to those inshore; (2) investigate the deep spawning ground habitat (Agulhas Bank mid-shelf) morphology and oceanographic environment; (3) determine the transport and survival of deep spawned hatchlings; and (4) investigate the origin and distribution of chokka squid paralarvae on the Agulhas Bank. The extent, depth range and importance of the deep spawning grounds, relative to those inshore was assessed using 23 years of demersal trawl survey data. Data for both the west and south coasts of South Africa were examined for egg capsules. No spawning was found on the west coast. Data showed that chokka squid preferred the Eastern Agulhas Bank for spawning. Spawning occurred not only inshore but also on the mid-shelf extending to depths of 270 m near the shelf edge. The majority of deep spawned eggs however, were found in the depth range 71-130 m. Squid egg density markedly decreased beyond 70 m, suggesting delineation between the inshore and deep spawning grounds. Total egg biomass calculations for depths shallower and deeper than 70 m indicated the coastal area to be strongly favoured, i.e. 82 vs. 18%. These results contest the commonly accepted notion that chokka squid is an inshore spawner and redefine the spawning grounds to extend across the shelf. Apart from an initial study investigating bottom temperature on the mid-shelf, very little is known about the deep spawning habitat. St Francis Bay, a commonly used spawning location, was chosen as a demonstration area for further study. The deep spawning grounds (71-130 m) were mapped and benthic habitat described from underwater video footage. A study investigating cross-shelf bottom conditions was undertaken off Thys Bay. CTD data were used to compare seasonal bottom temperature and oxygen on the St Francis Bay inshore and deep spawning grounds. Squid movement between the two spawning habitats was assessed using filament tagging. Predation and fishing pressure across the spawning grounds was reviewed. The mid-shelf benthic habitat was found to be similar to that inshore and available for spawning. Despite the generally colder bottom temperatures on the mid-shelf, this study showed that bottom temperature in deeper waters can at times be warmer than inshore. Although mid-shelf warming events lasted from a few hours to a number of days, they resulted in similar conditions to those on the inshore spawning grounds. It is likely these events act to expand or shift spawning habitat. The movement of squid between the two spawning habitats makes it possible for them to seek patches of warm bottom water with appropiate substrate. This suggests they are spawning habitat opportunists. Predation and fishing pressure appear to be higher on the inshore spawning grounds. It is feasible that this also forces spawners to seek out more favourable habitat offshore. An individual-based model was used to predict the fate of mid-shelf and inshore hatched paralarvae. Within the model, both the highly productive cold ridge and inshore spawning grounds were considered feeding or nursery areas. Paralarvae were released from six inshore and six deep spawning sites, spanning the coast between Port Alfred and Knysna. All paralarvae not reaching the feeding areas before the exhaustion of yolk-reserves (≤5 days), not retained within the feeding grounds (≥14 days), and not retained on the Agulhas Bank after exiting the feeding grounds were considered lost. This work illustrated the dependence of paralarval transport success on both spawning location and time of hatching, as established in earlier studies. The current IBM has expanded on initial work, emphasizing the importance of the cold ridge and inshore spawning grounds as nursery areas for deep and inshore spawned paralarvae, respectively. This work has highlighted the complex interactions between processes influencing recruitment variability for chokka squid. Possible relationships between periods of highest recruitment success and spawning peaks were identified for both spawning habitats. Based on the likely autumn increase in deep spawning off Tsitsikamma, and the beneficial currents during this period, it can be concluded deep spawning may at times contribute significantly to recruitment. This is particularly true for years where the cold ridge persists into winter. Data on chokka squid paralarval distribution are scarce. Paralarval distribution and abundance, in relation to Agulhas Bank oceanography, was investigated using bongo caught paralarvae and corresponding oceanographic data. Individual-based models (IBMs) were used to predict the origin or spawning site of the wild caught paralarvae, with reference to inshore versus deep spawning. Although failing to predict realistic points of origin, this study provided evidence to support a number of scenarios previously assumed to influence chokka squid recruitment. First is the possible influence of coastal upwelling on the retention, and hence spatial distribution, of paralarvae on the inshore spawning grounds. The second factor thought to impact recruitment is the loss of paralarvae from the Agulhas Bank ecosystem. This study confirmed the removal of paralarvae from the Eastern Agulhas Bank due to Agulhas Current boundary phenomena and resultant offshelf leakage. In addition, data suggested that the formation of the cold ridge could enhance retention on the Central Agulhas Bank, and so prevent offshelf leakage from the Central and Western Agulhas Bank. A synthesis of the main conclusions is presented. Implications of the findings and directions for future research are discussed.
- Full Text:
Towards the development of a larval feeding strategy for the white-margined sole (Dagetichthys marginatus)
- Authors: Thompson, Ernst Frederick
- Date: 2014
- Subjects: Flatfishes -- South Africa , Soleidae -- South Africa , Soleidae -- Larvae , Soleidae -- Larvae -- Feeding and feeds , Soleidae -- Larvae -- Physiology , Artemia
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5364 , http://hdl.handle.net/10962/d1012982
- Description: The major bottleneck during the domestication of the white-margined sole Dagetichthys marginatus in South Africa has been low larval survival. The cause of this is not clear but considering current literature on flatfish culture and more specifically soleid culture, nutritional deficiencies are hypothesized to be the main possible cause. Following the importance of nutrition, the first aim of the research was to use an ontogenetic developmental approach to develop a species specific larval feeding strategy. Ontogenetic development of D. marginatus showed that weaning will take place at much later ages than other soleids currently being farmed. This makes the partial replacement of Artemia with a suitable inert diet in co-feeding strategies very important to cut the cost associated of live food production. This leads on to the second aim, in which an 'in vitro' approach was used to model the digestibility of Artemia, which could ultimately contribute towards designing inert feeds with similar digestibility characteristics to Artemia in the future. Obtaining nutrients from food is closely linked to the functional status of the digestive tract, the support organs and the external morphological characteristics required for the ingestion of live or inert feeds. Considering both morphological and physiological ontogenetic development, it is clear that D. marginatus follow a similar pattern to other soleids. Larvae can successfully feed on Artemia as early as 3 days after hatching but exhibit a slow metamorphosis into the juvenile stage when compared to other soleids. The absence of any detectable acidic protease activity during the first 45 days of development and the importance of exogenous enzymes from Artemia all points to limited capacity to digest artificial diets. Prior to modelling the 'in vitro' digestion of Artemia, digestive enzyme activity at different pH's were modelled using functional forms from the normal distributive category of functions. , As there is no substantiated information for the general effects of pH on enzyme activity in the literature for finfish larvae, three species occurring in the same bio-geographical region of Dagetichthys marginatus, namely Sarpa salpa, Diplodus sargus capensis and Argyrosomus japonicus were used to investigate this effect. The fitted parameters, namely the optimal pH and sigma (the slope around the optimal pH) showed two interesting results. When using a negative log likelihood ratio test to test for differences between species for a particular enzyme, the optimal pH for alkaline proteases (7.67), lipase (8.03), amylase (7.69) and phosphatase (9.84) activity was the same for all three species. Furthermore, the study illustrated the potential to detect dietary shifts during ontogenetic development based on changes in enzyme activity around the optimal pH using the sigma parameter. Sarpa salpa showed increased amylase activity and a decrease in protease activity around the optimal pH with increased size, corresponding to a change in diet from zooplankton to algae. The 'in vitro' modelling approach taken in this study was based on known enzyme interactions and dynamics which makes the results very interpretable. from Artemia is achieved based on gut evacuation time and enzyme levels. This 'in vitro' study furthermore clearly indicates the importance of exogenous enzymes from Artemia, contributing as much as 54 percent to protein digestion and 64 – 72 percent to carbohydrate digestion. This was however, only an initial investigation, and further expansion of the model is required to achieve a complete understanding of Artemia digestion and ultimately partial replacement with artificial diets. A feeding strategy for D. marginatus should therefore follow those of other farmed soleids, although there will be a general delay in implementation due to slower development. Problems can thus be solved and improvements made by transferring technology from other soleids to D. marginatus.
- Full Text:
- Authors: Thompson, Ernst Frederick
- Date: 2014
- Subjects: Flatfishes -- South Africa , Soleidae -- South Africa , Soleidae -- Larvae , Soleidae -- Larvae -- Feeding and feeds , Soleidae -- Larvae -- Physiology , Artemia
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5364 , http://hdl.handle.net/10962/d1012982
- Description: The major bottleneck during the domestication of the white-margined sole Dagetichthys marginatus in South Africa has been low larval survival. The cause of this is not clear but considering current literature on flatfish culture and more specifically soleid culture, nutritional deficiencies are hypothesized to be the main possible cause. Following the importance of nutrition, the first aim of the research was to use an ontogenetic developmental approach to develop a species specific larval feeding strategy. Ontogenetic development of D. marginatus showed that weaning will take place at much later ages than other soleids currently being farmed. This makes the partial replacement of Artemia with a suitable inert diet in co-feeding strategies very important to cut the cost associated of live food production. This leads on to the second aim, in which an 'in vitro' approach was used to model the digestibility of Artemia, which could ultimately contribute towards designing inert feeds with similar digestibility characteristics to Artemia in the future. Obtaining nutrients from food is closely linked to the functional status of the digestive tract, the support organs and the external morphological characteristics required for the ingestion of live or inert feeds. Considering both morphological and physiological ontogenetic development, it is clear that D. marginatus follow a similar pattern to other soleids. Larvae can successfully feed on Artemia as early as 3 days after hatching but exhibit a slow metamorphosis into the juvenile stage when compared to other soleids. The absence of any detectable acidic protease activity during the first 45 days of development and the importance of exogenous enzymes from Artemia all points to limited capacity to digest artificial diets. Prior to modelling the 'in vitro' digestion of Artemia, digestive enzyme activity at different pH's were modelled using functional forms from the normal distributive category of functions. , As there is no substantiated information for the general effects of pH on enzyme activity in the literature for finfish larvae, three species occurring in the same bio-geographical region of Dagetichthys marginatus, namely Sarpa salpa, Diplodus sargus capensis and Argyrosomus japonicus were used to investigate this effect. The fitted parameters, namely the optimal pH and sigma (the slope around the optimal pH) showed two interesting results. When using a negative log likelihood ratio test to test for differences between species for a particular enzyme, the optimal pH for alkaline proteases (7.67), lipase (8.03), amylase (7.69) and phosphatase (9.84) activity was the same for all three species. Furthermore, the study illustrated the potential to detect dietary shifts during ontogenetic development based on changes in enzyme activity around the optimal pH using the sigma parameter. Sarpa salpa showed increased amylase activity and a decrease in protease activity around the optimal pH with increased size, corresponding to a change in diet from zooplankton to algae. The 'in vitro' modelling approach taken in this study was based on known enzyme interactions and dynamics which makes the results very interpretable. from Artemia is achieved based on gut evacuation time and enzyme levels. This 'in vitro' study furthermore clearly indicates the importance of exogenous enzymes from Artemia, contributing as much as 54 percent to protein digestion and 64 – 72 percent to carbohydrate digestion. This was however, only an initial investigation, and further expansion of the model is required to achieve a complete understanding of Artemia digestion and ultimately partial replacement with artificial diets. A feeding strategy for D. marginatus should therefore follow those of other farmed soleids, although there will be a general delay in implementation due to slower development. Problems can thus be solved and improvements made by transferring technology from other soleids to D. marginatus.
- Full Text:
Trophic relationships of hake (Merluccius capensis Castelnau, 1851 and M. paradoxus Franca 1960) from the Northern Benguela current ecosystem (Namibia) : inferences from stable isotopes and fatty acids
- Authors: Iitembu, Johannes Angala
- Date: 2014
- Subjects: Hake -- Benguela Current , Merlucciidae -- Benguela Current , Multitrophic interactions (Ecology) , Food chains (Ecology) , Biotic communities -- Benguela Current , Merlucciidae -- Food , Fishery management -- Namibia , Stable isotopes , Fatty acids
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5944 , http://hdl.handle.net/10962/d1020296
- Description: Two species of hake (Merluccius capensis and Merluccius paradoxus) account for most of Namibia’s fisheries catch, and they are important secondary consumers in the Benguela Current ecosystem. Inferences on their trophic relationships have been based mainly on stomach content analyses. However, such data are limited temporally because they represent only snapshots of recent feeding, and are quantitatively biased because of variation in the digestion rates of different prey. The principal aim of the thesis was to understand the trophic relationships of two hake species relative to each other, their known prey and top predators (demersal sharks) in the northern Benguela Current ecosystem (Namibia), using time-integrating trophic biomarkers. By using stable isotope (carbon and nitrogen) and fatty acid signatures of their muscle tissues, my overall objectives were to produce new knowledge about 1) hake ontogenic trophic relationships, 2) the contributions of different prey to hake diets, 3) hake dietary differences, and 4) some aspects of hake’s trophic relationships with demersal sharks. Tissues of hake (n=358), their potential prey (n=455), and demersal sharks (n=42) were collected between 2008 and 2012 during demersal bottom trawl surveys off Namibia, for stable isotope and fatty acid analyses. And more...
- Full Text:
- Authors: Iitembu, Johannes Angala
- Date: 2014
- Subjects: Hake -- Benguela Current , Merlucciidae -- Benguela Current , Multitrophic interactions (Ecology) , Food chains (Ecology) , Biotic communities -- Benguela Current , Merlucciidae -- Food , Fishery management -- Namibia , Stable isotopes , Fatty acids
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5944 , http://hdl.handle.net/10962/d1020296
- Description: Two species of hake (Merluccius capensis and Merluccius paradoxus) account for most of Namibia’s fisheries catch, and they are important secondary consumers in the Benguela Current ecosystem. Inferences on their trophic relationships have been based mainly on stomach content analyses. However, such data are limited temporally because they represent only snapshots of recent feeding, and are quantitatively biased because of variation in the digestion rates of different prey. The principal aim of the thesis was to understand the trophic relationships of two hake species relative to each other, their known prey and top predators (demersal sharks) in the northern Benguela Current ecosystem (Namibia), using time-integrating trophic biomarkers. By using stable isotope (carbon and nitrogen) and fatty acid signatures of their muscle tissues, my overall objectives were to produce new knowledge about 1) hake ontogenic trophic relationships, 2) the contributions of different prey to hake diets, 3) hake dietary differences, and 4) some aspects of hake’s trophic relationships with demersal sharks. Tissues of hake (n=358), their potential prey (n=455), and demersal sharks (n=42) were collected between 2008 and 2012 during demersal bottom trawl surveys off Namibia, for stable isotope and fatty acid analyses. And more...
- Full Text:
Understanding and modelling of surface and groundwater interactions
- Authors: Tanner, Jane Louise
- Date: 2014
- Subjects: Groundwater -- South Africa , Water-supply -- Management , Integrated water development , Hydrogeology , Water resources development -- South Africa , Water -- Analysis , Groundwater -- Management , Watersheds -- South Africa , Hydrologic models
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:6043 , http://hdl.handle.net/10962/d1012994
- Description: The connections between surface water and groundwater systems remain poorly understood in many catchments throughout the world and yet they are fundamental to effectively managing water resources. Managing water resources in an integrated manner is not straightforward, particularly if both resources are being utilised, and especially in those regions that suffer problems of data scarcity. This study explores some of the principle issues associated with understanding and practically modelling surface and groundwater interactions. In South Africa, there remains much controversy over the most appropriate type of integrated model to be used and the way forward in terms of the development of the discipline; part of the disagreement stems from the fact that we cannot validate models adequately. This is largely due to traditional forms of model testing having limited power as it is difficult to differentiate between the uncertainties within different model structures, different sets of alternative parameter values and in the input data used to run the model. While model structural uncertainties are important to consider, the uncertainty from input data error together with parameter estimation error are often more significant to the overall residual error, and essential to consider if we want to achieve reliable predictions for water resource decisions. While new philosophies and theories on modelling and results validation have been developed (Beven, 2002; Gupta et al., 2008), in many cases models are not only still being validated and compared using sparse and uncertain datasets, but also expected to produce reliable predictions based on the flawed data. The approach in this study is focused on fundamental understanding of hydrological systems rather than calibration based modelling and promotes the use of all the available 'hard' and 'soft' data together with thoughtful conceptual examination of the processes occurring in an environment to ensure as far as possible that a model is generating sensible results by simulating the correct processes. The first part of the thesis focuses on characterising the 'typical' interaction environments found in South Africa. It was found that many traditional perceptual models are not necessarily applicable to South African conditions, largely due to the relative importance of unsaturated zone processes and the complexity of the dominantly fractured rock environments. The interaction environments were categorised into four main 'types' of environment. These include karst, primary, fractured rock (secondary), and alluvial environments. Processes critical to Integrated Water Resource Management (IWRM) were defined within each interaction type as a guideline to setting a model up to realistically represent the dominant processes in the respective settings. The second part of the thesis addressed the application and evaluation of the modified Pitman model (Hughes, 2004), which allows for surface and groundwater interaction behaviour at the catchment scale to be simulated. The issue is whether, given the different sources of uncertainty in the modelling process, we can differentiate one conceptual flow path from another in trying to refine the understanding and consequently have more faith in model predictions. Seven example catchments were selected from around South Africa to assess whether reliable integrated assessments can be carried out given the existing data. Specific catchment perceptual models were used to identify the critical processes occurring in each setting and the Pitman model was assessed on whether it could represent them (structural uncertainty). The available knowledge of specific environments or catchments was then examined in an attempt to resolve the parameter uncertainty present within each catchment and ensure the subsequent model setup was correctly representing the process understanding as far as possible. The confidence in the quantitative results inevitably varied with the amount and quality of the data available. While the model was deemed to be robust based on the behavioural results obtained in the majority of the case studies, in many cases a quantitative validation of the outputs was just not possible based on the available data. In these cases, the model was judged on its ability to represent the conceptualisation of the processes occurring in the catchments. While the lack of appropriate data means there will always be considerable uncertainty surrounding model validation, it can be argued that improved process understanding in an environment can be used to validate model outcomes to a degree, by assessing whether a model is getting the right results for the right reasons. Many water resource decisions are still made without adequate account being taken of the uncertainties inherent in assessing the response of hydrological systems. Certainly, with all the possible sources of uncertainty in a data scarce country such as South Africa, pure calibration based modelling is unlikely to produce reliable information for water resource managers as it can produce the right results for the wrong reasons. Thus it becomes essential to incorporate conceptual thinking into the modelling process, so that at the very least we are able to conclude that a model generates estimates that are consistent with, and reflect, our understanding (however limited) of the catchment processes. It is fairly clear that achieving the optimum model of a hydrological system may be fraught with difficulty, if not impossible. This makes it very difficult from a practitioner's point of view to decide which model and uncertainty estimation method to use. According to Beven (2009), this may be a transitional problem and in the future it may become clearer as we learn more about how to estimate the uncertainties associated with hydrological systems. Until then, a better understanding of the fundamental and most critical hydrogeological processes should be used to critically test and improve model predictions as far as possible. A major focus of the study was to identify whether the modified Pitman model could provide a practical tool for water resource managers by reliably determining the available water resource. The incorporation of surface and groundwater interaction routines seems to have resulted in a more robust and realistic model of basin hydrology. The overall conclusion is that the model, although simplified, is capable of representing the catchment scale processes that occur under most South African conditions.
- Full Text:
- Authors: Tanner, Jane Louise
- Date: 2014
- Subjects: Groundwater -- South Africa , Water-supply -- Management , Integrated water development , Hydrogeology , Water resources development -- South Africa , Water -- Analysis , Groundwater -- Management , Watersheds -- South Africa , Hydrologic models
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:6043 , http://hdl.handle.net/10962/d1012994
- Description: The connections between surface water and groundwater systems remain poorly understood in many catchments throughout the world and yet they are fundamental to effectively managing water resources. Managing water resources in an integrated manner is not straightforward, particularly if both resources are being utilised, and especially in those regions that suffer problems of data scarcity. This study explores some of the principle issues associated with understanding and practically modelling surface and groundwater interactions. In South Africa, there remains much controversy over the most appropriate type of integrated model to be used and the way forward in terms of the development of the discipline; part of the disagreement stems from the fact that we cannot validate models adequately. This is largely due to traditional forms of model testing having limited power as it is difficult to differentiate between the uncertainties within different model structures, different sets of alternative parameter values and in the input data used to run the model. While model structural uncertainties are important to consider, the uncertainty from input data error together with parameter estimation error are often more significant to the overall residual error, and essential to consider if we want to achieve reliable predictions for water resource decisions. While new philosophies and theories on modelling and results validation have been developed (Beven, 2002; Gupta et al., 2008), in many cases models are not only still being validated and compared using sparse and uncertain datasets, but also expected to produce reliable predictions based on the flawed data. The approach in this study is focused on fundamental understanding of hydrological systems rather than calibration based modelling and promotes the use of all the available 'hard' and 'soft' data together with thoughtful conceptual examination of the processes occurring in an environment to ensure as far as possible that a model is generating sensible results by simulating the correct processes. The first part of the thesis focuses on characterising the 'typical' interaction environments found in South Africa. It was found that many traditional perceptual models are not necessarily applicable to South African conditions, largely due to the relative importance of unsaturated zone processes and the complexity of the dominantly fractured rock environments. The interaction environments were categorised into four main 'types' of environment. These include karst, primary, fractured rock (secondary), and alluvial environments. Processes critical to Integrated Water Resource Management (IWRM) were defined within each interaction type as a guideline to setting a model up to realistically represent the dominant processes in the respective settings. The second part of the thesis addressed the application and evaluation of the modified Pitman model (Hughes, 2004), which allows for surface and groundwater interaction behaviour at the catchment scale to be simulated. The issue is whether, given the different sources of uncertainty in the modelling process, we can differentiate one conceptual flow path from another in trying to refine the understanding and consequently have more faith in model predictions. Seven example catchments were selected from around South Africa to assess whether reliable integrated assessments can be carried out given the existing data. Specific catchment perceptual models were used to identify the critical processes occurring in each setting and the Pitman model was assessed on whether it could represent them (structural uncertainty). The available knowledge of specific environments or catchments was then examined in an attempt to resolve the parameter uncertainty present within each catchment and ensure the subsequent model setup was correctly representing the process understanding as far as possible. The confidence in the quantitative results inevitably varied with the amount and quality of the data available. While the model was deemed to be robust based on the behavioural results obtained in the majority of the case studies, in many cases a quantitative validation of the outputs was just not possible based on the available data. In these cases, the model was judged on its ability to represent the conceptualisation of the processes occurring in the catchments. While the lack of appropriate data means there will always be considerable uncertainty surrounding model validation, it can be argued that improved process understanding in an environment can be used to validate model outcomes to a degree, by assessing whether a model is getting the right results for the right reasons. Many water resource decisions are still made without adequate account being taken of the uncertainties inherent in assessing the response of hydrological systems. Certainly, with all the possible sources of uncertainty in a data scarce country such as South Africa, pure calibration based modelling is unlikely to produce reliable information for water resource managers as it can produce the right results for the wrong reasons. Thus it becomes essential to incorporate conceptual thinking into the modelling process, so that at the very least we are able to conclude that a model generates estimates that are consistent with, and reflect, our understanding (however limited) of the catchment processes. It is fairly clear that achieving the optimum model of a hydrological system may be fraught with difficulty, if not impossible. This makes it very difficult from a practitioner's point of view to decide which model and uncertainty estimation method to use. According to Beven (2009), this may be a transitional problem and in the future it may become clearer as we learn more about how to estimate the uncertainties associated with hydrological systems. Until then, a better understanding of the fundamental and most critical hydrogeological processes should be used to critically test and improve model predictions as far as possible. A major focus of the study was to identify whether the modified Pitman model could provide a practical tool for water resource managers by reliably determining the available water resource. The incorporation of surface and groundwater interaction routines seems to have resulted in a more robust and realistic model of basin hydrology. The overall conclusion is that the model, although simplified, is capable of representing the catchment scale processes that occur under most South African conditions.
- Full Text:
Vulnerability and adaptation of Zanzibar east coast communities to climate variability and change and other interacting stressors
- Authors: Makame, Makame Omar
- Date: 2014
- Subjects: Climatic changes -- Tanzania -- Zanzibar Bioclimatology Global temperature changes Food security -- Tanzania -- Zanzibar Water-supply -- Tanzania -- Zanzibar Sustainable development -- Tanzania -- Zanzibar Climatic changes -- Social aspects -- Tanzania -- Zanzibar Human ecology -- Tanzania -- Zanzibar Zanzibar -- Economic conditions
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4778 , http://hdl.handle.net/10962/d1011895
- Description: Climate variability and change as well as sea level rise poses significant challenges to livelihoods, water and food security in small island developing states (SIDSs) including the Zanzibar Islands. Thus, without planned strategic adaptation, the future projected changes in climate and sea level will intensify the vulnerability of these sensitive areas. This thesis is based on research conducted in two sites located in the north eastern parts of each island, namely Kiuyu Mbuyuni, Pemba Island and Matemwe, Unguja Island. The research focused firstly on assessing the vulnerability of these two coastal communities to climate variability and change and other stressors. This included investigation of (1) the perceptions of fishers, farmers and seaweed farmers regarding climate stressors and shocks and associated risks and impacts, (2) existing and possible future water and food security issues, and (3) household's access to important livelihood assets. This was followed by an exploration of the coping and adaptive responses of farmers, fishers and seaweed farmers to perceived shocks and stresses and some of the barriers to these responses. Lastly, an analysis of the implications of the findings for achieving sustainable coastal livelihoods and a resilient coastal community was undertaken. The general picture that emerges is that local people along the east coasts of both islands are already vulnerable to a wide range of stressors. Although variability in rainfall is not a new phenomenon in these areas, increasing frequency of dry spells and coastal floods resulting from the influence of El Niño and La Niña events exert enormous pressures on local activities (fishing, farming and seaweed farming) which are the crux of the local economy. The main argument of the study is that the nature and characteristics of these activities are the main source of sensitivity amongst these communities and this creates high levels of vulnerability to climate shocks and trends. This vulnerability is evidenced by the reoccurrence of localised food shortages and the observed food and water insecurity. The study found that food insecurity is a result of unreliable rainfall, drought and seasonality changes. These interacted with other contextual factors such as poor soil, low purchasing power and the lack of livelihood diversification options. In addition to exposure to these almost unavoidable risks from climate variability, the vulnerability of the local communities along the east coasts is also influenced by the low level of capital stocks and limited access to the assets that are important for coping and adaptation. Despite this, some households managed to overcome barriers and adapt in various ways both within the three main livelihood sectors (fishing, farming and seaweed farming) as well as through adopting options outside these sectors resulting in diversification of the livelihood portfolio. However, the study found that most of the strategies opted for by fishers, farmers and seaweed farmers were mainly spontaneous. Few planned adaptation measures supported by state authorities were observed across the sites, with the exception of the provision of motorised boats which were specifically meant to increase physical assets amongst fishers, reduce pressure in the marine conservation areas and prevent overfishing in-shore. Furthermore, numerous strategies that people adopted were discontinued when further barriers were encountered. Interestingly, some of the barriers that prevented households adapting were the same ones that forced households that had responded to abandon their adaptations. To increase resilience amongst east coast communities to current and future predicted changes in climate and sea level, the study argues that traditional livelihood activities (fishing, farming and seaweed farming) need to be better supported, and access to a range of livelihood assets improved. This may be achieved through increased access to local sources of water and facilitation of rainwater harvesting, expanding the livelihood options available to people and increasing climate change awareness, and access to sources of credit.
- Full Text:
- Authors: Makame, Makame Omar
- Date: 2014
- Subjects: Climatic changes -- Tanzania -- Zanzibar Bioclimatology Global temperature changes Food security -- Tanzania -- Zanzibar Water-supply -- Tanzania -- Zanzibar Sustainable development -- Tanzania -- Zanzibar Climatic changes -- Social aspects -- Tanzania -- Zanzibar Human ecology -- Tanzania -- Zanzibar Zanzibar -- Economic conditions
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4778 , http://hdl.handle.net/10962/d1011895
- Description: Climate variability and change as well as sea level rise poses significant challenges to livelihoods, water and food security in small island developing states (SIDSs) including the Zanzibar Islands. Thus, without planned strategic adaptation, the future projected changes in climate and sea level will intensify the vulnerability of these sensitive areas. This thesis is based on research conducted in two sites located in the north eastern parts of each island, namely Kiuyu Mbuyuni, Pemba Island and Matemwe, Unguja Island. The research focused firstly on assessing the vulnerability of these two coastal communities to climate variability and change and other stressors. This included investigation of (1) the perceptions of fishers, farmers and seaweed farmers regarding climate stressors and shocks and associated risks and impacts, (2) existing and possible future water and food security issues, and (3) household's access to important livelihood assets. This was followed by an exploration of the coping and adaptive responses of farmers, fishers and seaweed farmers to perceived shocks and stresses and some of the barriers to these responses. Lastly, an analysis of the implications of the findings for achieving sustainable coastal livelihoods and a resilient coastal community was undertaken. The general picture that emerges is that local people along the east coasts of both islands are already vulnerable to a wide range of stressors. Although variability in rainfall is not a new phenomenon in these areas, increasing frequency of dry spells and coastal floods resulting from the influence of El Niño and La Niña events exert enormous pressures on local activities (fishing, farming and seaweed farming) which are the crux of the local economy. The main argument of the study is that the nature and characteristics of these activities are the main source of sensitivity amongst these communities and this creates high levels of vulnerability to climate shocks and trends. This vulnerability is evidenced by the reoccurrence of localised food shortages and the observed food and water insecurity. The study found that food insecurity is a result of unreliable rainfall, drought and seasonality changes. These interacted with other contextual factors such as poor soil, low purchasing power and the lack of livelihood diversification options. In addition to exposure to these almost unavoidable risks from climate variability, the vulnerability of the local communities along the east coasts is also influenced by the low level of capital stocks and limited access to the assets that are important for coping and adaptation. Despite this, some households managed to overcome barriers and adapt in various ways both within the three main livelihood sectors (fishing, farming and seaweed farming) as well as through adopting options outside these sectors resulting in diversification of the livelihood portfolio. However, the study found that most of the strategies opted for by fishers, farmers and seaweed farmers were mainly spontaneous. Few planned adaptation measures supported by state authorities were observed across the sites, with the exception of the provision of motorised boats which were specifically meant to increase physical assets amongst fishers, reduce pressure in the marine conservation areas and prevent overfishing in-shore. Furthermore, numerous strategies that people adopted were discontinued when further barriers were encountered. Interestingly, some of the barriers that prevented households adapting were the same ones that forced households that had responded to abandon their adaptations. To increase resilience amongst east coast communities to current and future predicted changes in climate and sea level, the study argues that traditional livelihood activities (fishing, farming and seaweed farming) need to be better supported, and access to a range of livelihood assets improved. This may be achieved through increased access to local sources of water and facilitation of rainwater harvesting, expanding the livelihood options available to people and increasing climate change awareness, and access to sources of credit.
- Full Text:
‘Gender’ and constructions of spousal mourning among the AmaXhosa in the Eastern Cape
- Authors: Ngqangweni, Hlonelwa
- Date: 2014
- Subjects: Widowhood -- South Africa -- Eastern Cape , Widows -- South Africa -- Eastern Cape , Xhosa (African people) -- Funeral customs and rites , Xhosa (African people) -- Psychology , Bereavement -- Psychological aspects , Mourning customs -- South Africa -- Eastern Cape , Death -- Social aspects -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3249 , http://hdl.handle.net/10962/d1015647
- Description: Among the AmaXhosa the death of a person is marked by a tradition called ukuzila - the equivalent of the mourning process. As a sign of spousal mourning, and to show respect, the remaining spouse has to put on a marker (be visible). However, it is mostly the woman who is under obligation to show her mourner status by wearing ‘clothes of mourning’. The discriminatory nature of the practice, especially pertaining to visibility and some of the detrimental effects on the widows’ health and safety have been documented by some researchers, but the reasons for the continuity of visibility remain largely unexplored. Taking into account the dynamic nature of ‘culture’, this research explored the discourses deployed in men and women’s constructions of ukuzila specifically focusing on spousal mourning and the continuity of widows’ visibility in spite of their resistance to it. The research used postcolonial feminism drawing on postructuralism as its theoretical lens. This theoretical lens provided useful concepts such as hybridity, visibility, surveillance and power with which to examine spousal mourning and conceptualised people’s subject positions as multiple, fluid and contingent. Furthermore, the research employed thematic and discourse analysis at its methodology. Discourse analysis was employed to identify and analyse the discourses utilised in the constructions of spousal mourning. The research was conducted through focus group discussions held with younger and older urban and rural men and women, as well as interviews held with widows and widowers and key cultural informants. Concerning the question of constructions of spousal mourning for men and women, visibility of the mourner emerged as a central and contentious issue. Some participants were of the view that one could show mourning by engaging in culturally appropriate mourning behaviour, whilst others were of the view that showing one’s mourning had to be visible by publicly displaying mourning through a marker. Another group proposed mourning “by heart”, whereby the mourners’ status could either be inferred from their behaviour, whereas others maintained that behaviour was not mandatory. Various justifications for the continued visibility of widows were advanced. These justifications included showing love and respect to the deceased husband; showing respect to the ancestors; and helping to monitor their own behaviour in order to ensure that it is in line with appropriate mourning behaviour. The continued visibility of widows was also used to regulate the widows’ sexuality. Widows were coerced to put on ‘clothes of mourning’ in order to ‘protect’ them from being approached by men for a relationship during the mourning period. The regulation of the movement of widows was also managed through visibility. Widows’ movements were restricted in order to protect the community from pollution or bad luck. For example, they were not allowed to visit places of entertainment or visit other households. Key discourses identified were the familial-‘ukwenda’, respect-‘hlonipha’, and male sexual drive (MSD) discourse. The familial - ‘ukwenda’ discourse is centred on the idea that one is ‘married to the household’, which includes the nuclear family and wider extended family including ancestors. According to the respect-‘hlonipha’ discourse, respect is due to others on the basis of their age, status, and more especially their gender. Showing respect (hlonipha) necessitates the avoidance of all forms of behaviour and utterances that could be deemed disrespectful. The MSD holds a widespread view of sexuality as a biological drive that resides within each male and it was drawn on to make sense of discontinued visibility among widowers, whilst visibility of widows continued. It is argued that it is these discourses, embedded in the ‘culture’ of the AmaXhosa and upheld by the family that sustain the discriminatory nature of the practice, especially concerning the continued visibility of widows in spite of the resistance that has been voiced.
- Full Text:
- Authors: Ngqangweni, Hlonelwa
- Date: 2014
- Subjects: Widowhood -- South Africa -- Eastern Cape , Widows -- South Africa -- Eastern Cape , Xhosa (African people) -- Funeral customs and rites , Xhosa (African people) -- Psychology , Bereavement -- Psychological aspects , Mourning customs -- South Africa -- Eastern Cape , Death -- Social aspects -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3249 , http://hdl.handle.net/10962/d1015647
- Description: Among the AmaXhosa the death of a person is marked by a tradition called ukuzila - the equivalent of the mourning process. As a sign of spousal mourning, and to show respect, the remaining spouse has to put on a marker (be visible). However, it is mostly the woman who is under obligation to show her mourner status by wearing ‘clothes of mourning’. The discriminatory nature of the practice, especially pertaining to visibility and some of the detrimental effects on the widows’ health and safety have been documented by some researchers, but the reasons for the continuity of visibility remain largely unexplored. Taking into account the dynamic nature of ‘culture’, this research explored the discourses deployed in men and women’s constructions of ukuzila specifically focusing on spousal mourning and the continuity of widows’ visibility in spite of their resistance to it. The research used postcolonial feminism drawing on postructuralism as its theoretical lens. This theoretical lens provided useful concepts such as hybridity, visibility, surveillance and power with which to examine spousal mourning and conceptualised people’s subject positions as multiple, fluid and contingent. Furthermore, the research employed thematic and discourse analysis at its methodology. Discourse analysis was employed to identify and analyse the discourses utilised in the constructions of spousal mourning. The research was conducted through focus group discussions held with younger and older urban and rural men and women, as well as interviews held with widows and widowers and key cultural informants. Concerning the question of constructions of spousal mourning for men and women, visibility of the mourner emerged as a central and contentious issue. Some participants were of the view that one could show mourning by engaging in culturally appropriate mourning behaviour, whilst others were of the view that showing one’s mourning had to be visible by publicly displaying mourning through a marker. Another group proposed mourning “by heart”, whereby the mourners’ status could either be inferred from their behaviour, whereas others maintained that behaviour was not mandatory. Various justifications for the continued visibility of widows were advanced. These justifications included showing love and respect to the deceased husband; showing respect to the ancestors; and helping to monitor their own behaviour in order to ensure that it is in line with appropriate mourning behaviour. The continued visibility of widows was also used to regulate the widows’ sexuality. Widows were coerced to put on ‘clothes of mourning’ in order to ‘protect’ them from being approached by men for a relationship during the mourning period. The regulation of the movement of widows was also managed through visibility. Widows’ movements were restricted in order to protect the community from pollution or bad luck. For example, they were not allowed to visit places of entertainment or visit other households. Key discourses identified were the familial-‘ukwenda’, respect-‘hlonipha’, and male sexual drive (MSD) discourse. The familial - ‘ukwenda’ discourse is centred on the idea that one is ‘married to the household’, which includes the nuclear family and wider extended family including ancestors. According to the respect-‘hlonipha’ discourse, respect is due to others on the basis of their age, status, and more especially their gender. Showing respect (hlonipha) necessitates the avoidance of all forms of behaviour and utterances that could be deemed disrespectful. The MSD holds a widespread view of sexuality as a biological drive that resides within each male and it was drawn on to make sense of discontinued visibility among widowers, whilst visibility of widows continued. It is argued that it is these discourses, embedded in the ‘culture’ of the AmaXhosa and upheld by the family that sustain the discriminatory nature of the practice, especially concerning the continued visibility of widows in spite of the resistance that has been voiced.
- Full Text:
“The stranger at home” : representations of home and hospitality in three South African post-transitional novels
- Authors: Dass, Minesh
- Date: 2014
- Subjects: South African fiction (English) -- History and criticism , Wicomb, Zoë -- Criticism and interpretation , Shukri, Ishtiyaq, 1968- -- Criticism and interpretation , Vladislavić, Ivan, 1957- -- Criticism and interpretation , Home in literature , Hospitality in literature
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2325 , http://hdl.handle.net/10962/d1016355
- Description: This thesis examines the representation of home and hospitality in Zoë Wicomb’s Playing in the Light, Ishtiyaq Shukri’s The Silent Minaret, and Ivan Vladislavić’s Double Negative. It attempts to trace the un-homeliness of the central characters and to account for their feelings of discomfort. As such, it argues that the home is incapable of being inviolable because the invasion of the public is always a possibility. The implication is that master narratives such as race, history and politics are always entering the space one constructs as private. That said, this study also argues that the home and those things with which it is most closely associated, such as belonging, comfort and safety, may actually hide a form of violence. By this I mean that in the desire for homeliness, one may exclude others from one’s home. Consequently, this argument draws on Jacques Derrida’s writings on the aporia of conditional and unconditional hospitality to investigate what ethical possibilities might, somewhat unexpectedly, be created by the un-homely home. The study is therefore an exploration of the potentials that inhere in a certain kind of un-homeliness, the most important of which is the chance to respond ethically to the alterity of the other. In sum, there is a necessity to extend hospitality beyond condition and beyond limit, and this ethical imperative is at odds with the desire for comfort and safety. The way in which post-transitional novels explore these issues of hospitality and home is the primary focus of this study.
- Full Text:
- Authors: Dass, Minesh
- Date: 2014
- Subjects: South African fiction (English) -- History and criticism , Wicomb, Zoë -- Criticism and interpretation , Shukri, Ishtiyaq, 1968- -- Criticism and interpretation , Vladislavić, Ivan, 1957- -- Criticism and interpretation , Home in literature , Hospitality in literature
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2325 , http://hdl.handle.net/10962/d1016355
- Description: This thesis examines the representation of home and hospitality in Zoë Wicomb’s Playing in the Light, Ishtiyaq Shukri’s The Silent Minaret, and Ivan Vladislavić’s Double Negative. It attempts to trace the un-homeliness of the central characters and to account for their feelings of discomfort. As such, it argues that the home is incapable of being inviolable because the invasion of the public is always a possibility. The implication is that master narratives such as race, history and politics are always entering the space one constructs as private. That said, this study also argues that the home and those things with which it is most closely associated, such as belonging, comfort and safety, may actually hide a form of violence. By this I mean that in the desire for homeliness, one may exclude others from one’s home. Consequently, this argument draws on Jacques Derrida’s writings on the aporia of conditional and unconditional hospitality to investigate what ethical possibilities might, somewhat unexpectedly, be created by the un-homely home. The study is therefore an exploration of the potentials that inhere in a certain kind of un-homeliness, the most important of which is the chance to respond ethically to the alterity of the other. In sum, there is a necessity to extend hospitality beyond condition and beyond limit, and this ethical imperative is at odds with the desire for comfort and safety. The way in which post-transitional novels explore these issues of hospitality and home is the primary focus of this study.
- Full Text:
“Watch-dogs for an Economy” : a determination of the origins of the South African Public Accountants' and Auditors' Board – as the Regulator of the Profession – principally through an analysis of the debates and related reports to the House of Assembly of the Parliament of the Union of South Africa in the period 1913–1940
- Lancaster, Jonathan Charles Swinburne
- Authors: Lancaster, Jonathan Charles Swinburne
- Date: 2014
- Subjects: Public Accountants' and Auditors' Board (South Africa) , Accounting -- Law and legislation -- South Africa , Accounting -- South Africa -- History , Accounting -- Standards -- South Africa , South Africa -- Economic conditions -- 1918-1961 , South Africa -- Politics and government -- 1909-1948
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:922 , http://hdl.handle.net/10962/d1020876
- Description: This thesis concentrates upon a new field of research in South African accounting scholarship – this being, in general terms, accounting history and more specifically an analysis of the origins of the Public Accountants’ and Auditors’ Board as watch-dog in relation to: ● the South African economy in the period 1913–1940; and ● the changing political framework (also in the period 1913–1940). The integration of economy, politics and personal ambition on the part of early 20th Century accounting societies, led to a variety of responses, counter proposals, stalemates and unfocused activity which caused the process of accountants’ registration to extend over 38 years in South Africa. This confusion was in strong contrast to the process of speedy registration of accountants in New Zealand and Australia. The final unification of South African accounting societies in 1951 created the Public Accountants’ and Auditors’ Board. Its creation, at long last, suggested an overarching control and regulation which was mirrored in the final political unification and economic stability of a South Africa dominated by Afrikaner Nationalists. One further element was interwoven into the fabric of the thesis – this being the application of institutional economic theory and its impact upon the accounting concepts of “material irregularity” and “reportable irregularity”.
- Full Text:
- Authors: Lancaster, Jonathan Charles Swinburne
- Date: 2014
- Subjects: Public Accountants' and Auditors' Board (South Africa) , Accounting -- Law and legislation -- South Africa , Accounting -- South Africa -- History , Accounting -- Standards -- South Africa , South Africa -- Economic conditions -- 1918-1961 , South Africa -- Politics and government -- 1909-1948
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:922 , http://hdl.handle.net/10962/d1020876
- Description: This thesis concentrates upon a new field of research in South African accounting scholarship – this being, in general terms, accounting history and more specifically an analysis of the origins of the Public Accountants’ and Auditors’ Board as watch-dog in relation to: ● the South African economy in the period 1913–1940; and ● the changing political framework (also in the period 1913–1940). The integration of economy, politics and personal ambition on the part of early 20th Century accounting societies, led to a variety of responses, counter proposals, stalemates and unfocused activity which caused the process of accountants’ registration to extend over 38 years in South Africa. This confusion was in strong contrast to the process of speedy registration of accountants in New Zealand and Australia. The final unification of South African accounting societies in 1951 created the Public Accountants’ and Auditors’ Board. Its creation, at long last, suggested an overarching control and regulation which was mirrored in the final political unification and economic stability of a South Africa dominated by Afrikaner Nationalists. One further element was interwoven into the fabric of the thesis – this being the application of institutional economic theory and its impact upon the accounting concepts of “material irregularity” and “reportable irregularity”.
- Full Text: