Is inflation targeting a viable option for a developing country?: the case of Malawi
- Authors: Hompashe, Dumisani MacDonald
- Date: 2009
- Subjects: Inflation (Finance) -- Malawi -- Case studies , Banks and banking, Central -- Malawi , Monetary policy -- Malawi , Finance -- Developing countries , Debts, External -- Developing countries
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:943 , http://hdl.handle.net/10962/d1002676 , Inflation (Finance) -- Malawi -- Case studies , Banks and banking, Central -- Malawi , Monetary policy -- Malawi , Finance -- Developing countries , Debts, External -- Developing countries
- Description: The distinctive features of inflation targeting include the publishing of the formal (official) target band or point target for the rate of inflation at one or more time horizons and the explicit confirmation that low and steady inflation is the long-run objective of monetary policy. There are four main preconditions of inflation targeting: 1) an independent central bank that is free from fiscal and political pressures; 2) a central bank that has both the ability to forecast inflation and the capability to model inflation data; 3) the presence of fully deregulated prices and an economy that is affected by changes of commodity prices, as well as exchange rates; and 4) the presence of sound banking system and well developed capital markets. In most developing countries, the use of seigniorage revenues as a source of financing government debts, the lack of commitment by monetary authorities to low inflation as a primary goal, the absence of the central bank’s functional independence, and of powerful models to make domestic inflation forecasts, prevent the satisfaction of these preconditions. This dissertation investigates the extent to which Malawi meets the preconditions for inflation targeting by comparing the situation in that country to other developing countries, which have already adopted the framework. Malawi is committed to the central bank’s functional independence as well as the pursuit of prudent fiscal policy measures for the attainment of low inflation. Despite the failure to meet all the preconditions, this study recommends that Malawi should adopt an inflation targeting framework due to the strength of commitment of the monetary authorities in satisfying these preconditions.
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Labour hire: the impact of labour broking on employee job satisfaction and commitment in a number of Namibian organizations
- Authors: Shivangulula, Shirley Euginia
- Date: 2009
- Subjects: Temporary employment -- Namibia , Industrial relations -- Namibia , Employee motivation , Labor market -- Namibia , Labor policy -- Namibia
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:3054 , http://hdl.handle.net/10962/d1002563 , Temporary employment -- Namibia , Industrial relations -- Namibia , Employee motivation , Labor market -- Namibia , Labor policy -- Namibia
- Description: Over decades, job satisfaction has generated active empirical research. Similarly, organizational commitment, another attitudinal variable in the work domain, strongly related to, but distinctly different from job satisfaction, received comparatively equal research scrutiny. However, research on the impact of labour broking on employees’ job satisfaction and organizational commitment is nonexistent in Namibia. Using a quantitative approach, within a positivist paradigm, the purpose of this thesis was to examine the impact of labour broking on employees’ job satisfaction and organizational commitment as well as to determine the dynamics that mediate such experiences. These experiences were examined through a 5-dimensional, 72-item Job Descriptive Index and a 3-dimensional, 12-item Organizational Commitment Questionnaire over a sample size of 108 temporary and permanent employees, drawn through random probability sampling in a number of Namibian organizations that make use of labour hire services. These experiences were further amplified by face-to-face interviews over a sub sample of 20 employees. Data analysis was carried out using the chi-square, correlation, t-tests and multiple regression techniques of the STATISTICA software. Drawing on the principles of the multi dimensional theory of organizational commitment, the Cornell dispositional theory of job satisfaction and the temporary employee stigmatization model, results revealed that variables of employment status, tenure, inadequate income, inappropriate supervision and fear of job losses ahead of a newly proposed piece of legislat st labour hire ractices significantly influenced job satisfaction and organizational commitment of employees. Estimates indicate that for a mere change in tenure, job satisfaction levels will significantly rise by 0.26 units, whereas organizational commitment will augment by 0.03 units. However, for every N$ fall in employees’ pay, we can expect job satisfaction levels to decrease by 26%, but with significant effects. The study recommends that organizations must adopt policies that grant permanent tenure to all their employees, position them in respected and challenging jobs in which they will grow skills and ensure that all employees are remunerated with pay that signals their contribution to the organizations. In doing so, the negative effects of labour broking will disappear and employees will be satisfied with their jobs and Tommitted to their organizations.
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Land reform in South Africa: effects on land prices and productivity
- Authors: Van Rooyen, Jonathan
- Date: 2009
- Subjects: Right of property -- South Africa , Land reform -- South Africa , Agriculture and state -- South Africa , Agricultural prices -- South Africa , Land tenure -- Government policy -- South Africa , Land reform -- Economic aspects -- South Africa , Real property -- Prices -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:987 , http://hdl.handle.net/10962/d1002721
- Description: South Africa’s land redistribution policy (1994-2008) has been widely publicised, and has come under scrutiny of late from the public, private and government spheres, highlighting a need for research in this area. The research examines progress in South Africa’s land redistribution programme in two of KwaZulu-Natal’s district municipalities, Uthungulu and iLembe. Specifically the research investigates whether the government has paid above market prices when purchasing sugarcane farmland for redistribution in these districts. Moreover, it is illustrated how productivity on redistributed farms has been affected with the changes in ownership. To investigate the research questions, reviews of theories pertaining to property rights, land reform and market structures were conducted. Moreover, two cases studies were conducted in the districts of Uthungulu and iLembe, with assistance from the Department of Land Affairs, Inkezo Land Company and the South African Cane Growers Association. The case study data indicate that above ordinary market prices have been paid (2004-2006) by the government for sugarcane farmland in the districts concerned, and further that productivity has been negatively impacted ‘during’ and ‘post‘ transfer, in the majority of cases.
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Lead-radium dating of two deep-water fishes from the southern hemisphere, Patagonian toothfish (Dissostichus eleginoides) and Orange Roughy (Hoplostethus atlanticus)
- Authors: Andrews, Allen Hia
- Date: 2009
- Subjects: Fishes -- Age determination , Fishes -- Southern hemisphere -- Longevity , Fishes -- Growth , Radioactive dating , Patagonian toothfish , Patagonian toothfish -- Fisheries , Orange roughy , Orange roughy -- Fisheries , Deep-sea fishes -- Southern hemisphere , Deep-sea fisheries , Deep-sea fisheries -- Southern hemisphere
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5295 , http://hdl.handle.net/10962/d1005140
- Description: Patagonian toothfish (Dissostichus eleginoides) or "Chilean sea bass" support a valuable and controversial fishery, but the life history is little known and longevity estimates range from ~20 to more than 40 or 50 yr. In this study, lead-radium dating provided validated age estimates from juveniles to older adults, supporting the use of otoliths as accurate indicators of age. The oldest age groups were near 30 yr, which provided support for age estimates exceeding 40 or 50 yr from grow zone counts in otolith sections. Hence, scale reading, which rarely exceeds 20 years, has the potential for age underestimation. Lead-radium dating revealed what may be minor differences in age interpretation between two facilities and findings may provide an age-validated opportunity for the CCAMLR Otolith Network to reassess otolith interpretations. Orange roughy (Hoplostethus atlanticus) support a major deep-sea fishery and stock assessments often depend on age analyses, but lifespan estimates range from ~20 to over 100 yr and validation of growth zone counts remained unresolved. An early application of lead-radium dating supported centenarian ages, but the findings were met with disbelief and some studies have attempted to discredit the technique and the long lifespan. In this study, an improved lead-radium dating technique used smaller samples than previously possible and circumvented assumptions that were previously necessary. Lead-radium dating of otolith cores, the first few years of growth, provided ratios that correlated well with the ingrowth curve. This provided robust support for age estimates from otolith thin sections. Use of radiometric ages as independent age estimates indicated the fish in the oldest group were at least 93 yr. Lead-radium dating has validated a centenarian lifespan for orange roughy. To date, radium-226 has been measured in otoliths of 39 fish species ranging from the northern Pacific and Atlantic Oceans to the Southern Ocean. In total, 367 reliable radium-226 measurements were made in 36 studies since the first lead-radium dating study on fish in 1982. The activity of radium-226 measurements ranged over 3 orders of magnitude (<0.001 to >1.0 dpm.g⁻¹). An analysis revealed ontogenetic differences in radium-226 uptake that may be attributed to changes in habitat or diet. Radiometric age from otolith core studies was used to describe a radium-226 uptake time-series for some species, which revealed interesting patterns over long periods. This synopsis provides information on the uptake of radium-226 to otoliths from an environmental perspective, which can be used as a basis for future studies.
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Learning, governance and livelihoods : toward adaptive co-management under resource poor conditions in South Africa
- Authors: Cundill, Georgina
- Date: 2009
- Subjects: Natural resources -- Co-management -- South Africa Rural poor -- South Africa Rural development -- South Africa Households -- Economic aspects -- South Africa Sustainable development -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4747 , http://hdl.handle.net/10962/d1006961
- Description: Through collaborative monitoring and case study comparison, this thesis explores conceptual and methodological approaches to monitoring transitions toward adaptive co-management. In so doing, a number of knowledge gaps are addressed. Firstly, conceptual and methodological frameworks are developed for monitoring transitions toward adaptive co-management. Secondly, a conceptual and practical approach to monitoring the processes of collaboration and learning is developed and tested. Thirdly, a conceptual and practical approach to monitoring the governance outcomes of adaptive co-management is developed and tested. Fourthly, a conceptual and practical approach to monitoring the livelihood outcomes of adaptive co-management is developed and tested. Based on the outcomes from these four components of the study, this thesis explores the ways in which transitions toward adaptive co-management might be initiated under the resource poor conditions that characterise South Africa's communal areas. The four case studies explored in the study are described as 'resource poor' in terms of institutional capacity, ecosystem productivity and social vulnerability. From a resilience perspective these case studies can be described as being in the re-organisation phase of the adaptive cycle following multiple disturbances over time, largely due to South Africa's historical 'separate development' policies. Scholars have suggested that it is in this re-organisation phase that innovation and novelty might occur. The lens of social learning is applied to analyse collaborative processes within these contexts. Results indicate that the institutional innovation necessary for transitions toward adaptive co-management relies on careful facilitation by an 'honest broker'. Equally important is finding a balance between maintaining key individuals and knowledge holders within decision making networks, and preventing rigidity and vulnerability within communities of practice. The results point to an over simplification in the rhetoric that currently surrounds the learning outcomes of multi level networks. The governance outcomes of the initiatives are explored through the lenses of adaptive governance, social capital, adaptive capacity and self-organisation. Results indicate that under resource poor conditions creating the conditions that facilitate self-organisation is the major challenge facing transformations toward adaptive governance. Long term access to reliable information and capacity and financial support for adaptive management are key constraining variables. The livelihood outcomes of the initiatives are analysed through the lens of resilience and diversification. Results suggest that flexibility, rather than livelihood diversity, is the key livelihood strategy employed by households in situations were options are limited. Interventions that enhance opportunities for households to specialise in situ by actively dealing with structural constraints, such as access to markets and credit, is vital to encouraging innovation during transitions toward adaptive co-management. Based on the results from monitoring, this study identifies key focus areas that require a great deal more attention if transitions toward adaptive co-management are to be initiated under resource poor conditions.
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Legal access to our musical history: an investigation into the copyright implications of archived musical recordings held at the International Library of African Music (ILAM) in South Africa
- Authors: McConnachie, Boudina
- Date: 2009
- Subjects: Tracey, Hugh International Library of African Music South Africa. Copyright Act 1978 Copyright -- Music -- South Africa Music -- History and criticism
- Language: English
- Type: Thesis , Masters , MMus
- Identifier: vital:2648 , http://hdl.handle.net/10962/d1002313
- Description: This thesis explores the South African Copyright Act No. 98 of 1978 as it pertains to the archived holdings at the International Library of African Music (ILAM) situated at Rhodes University, Grahamstown, South Africa. The purpose of analysing this law is to advise and assist ILAM in fulfilling royalty payment obligations as stipulated in a contract signed between ILAM and the Smithsonian Global Sound (formally Global Sound Network) in 2001. In order to clearly comprehend the scope of the royalty payment clause in the Smithsonian Institution’s contract with ILAM, this research includes an examination of: the history and nature of South African copyright as a sub-structure of intellectual property; specific internationally documented copyright infringement cases; the recording and documentation practices of Hugh Tracey (ILAM’s founder and director from 1954 to 1977); the contract between Global Sound Network and ILAM; and contentious issues surrounding collective ownership and indigenous knowledge. In conclusion, this research suggests equitable solutions to ILAM’s copyright concerns and proposes the Eastern Cape Music Archiving Project (ECMAP) as a practical vehicle to assist the South African Department of Trade and Industry in implementation of the South African Intellectual Property Amendment Bill (2008) if, and when, it is passed.
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Liberalisation and regulation of trade in the Southern African Development Community (SADC) : a critical analysis of the SADC trade protocol's provisions and its implementation
- Authors: Dube, Memory
- Date: 2009
- Subjects: General Agreement on Tariffs and Trade (Organization) World Trade Organization Customs unions Foreign trade regulation Free trade -- Africa, Southern Southern African Development Community International trade
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:3716 , http://hdl.handle.net/10962/d1008204
- Description: The Southern African Development Community (SADC) declared a Free Trade Area on 17 August 2008. The Free Trade Area is the ultimate objective of the Trade Protocol on trade cooperation in SADC, signed in 1996. The Protocol is supported and complemented by the ambitious Regional Indicative Strategic Development Plan (RISDP). The idea behind the SADC Trade Protocol was to counter the developmental challenges facing SADC member states and to improve the productive and trade capacity of SADC countries. The implementation of the SADC Free Trade Area has been guided by the WTO/GATT regulatory framework on regional trade agreements, particularly GATT Article XXIV, the Understanding on the Interpretation of GATT Article XXIV, as well as the Decision on Differential and More Favourable Treatment, Reciprocity and Fuller Participation of Developing Countries (Enabling Clause). This research seeks to analyse the SADC Trade Protocol's provisions and the implementation of such provisions. To facilitate an understanding of factors that affect the implementation of the SADC Trade Protocol, SADC's institutional and operational framework is discussed from a legal-historical perspective. The provisions of the Trade Protocol are analysed for compliance with WTO/GA TT rules as well as for applicability within the SADC context. The provisions of the WTO/GA TT regulatory framework on regional trade agreements are also analysed with a view to determining whether they are applicable in developing country situations such as SADC. The Free Trade Area is seen as the first step towards regional economic integration in the region and is to be followed by a Customs Union, a Common Market and then eventually an Economic Community with its own central bank and regional currency. It is envisaged that the region will proceed through all these traditional theoretical phases of economic integration between 2008 and 2018. The implementation of the Trade Protocol has been beset with institutional, administrative and infrastructural challenges which pose obstacles to the attainment of the other stages of economic integration in the time frames prescribed in the RISDP. These challenges are assessed for impact on the regional economic integration of SADC by evaluating the progress towards implementing the Trade Protocol provisions and the implementation of measures taken towards the launch of the Free Trade Area. Emerging issues are also identified and analysed for their effect on the Free Trade Area and the general economic agenda of SADC. Of particular note is the Economic Partnership Agreements (EPAs) being negotiated with the European Union where SADC countries are negotiating in four different configurations. An analysis of this EPA situation reveals that it compounds a pre-existing problem: that of overlapping membership of regional trade agreements. Prior to the EPAs and the intensified drive towards the creation of the Customs Union, there was largely no need to rationalise the overlap in regional trade agreement memberships, but it is now a matter of urgency. The overlap in membership has complicated EPA negotiations and places serious doubts on the prospects of complete regional integration in SADC.This research concludes with observations on South Africa's complicated relationship with her SADC neighbours. South Africa's trade policies, as regards both the SADC region and the world, are discussed. Because of its political and economic dominance, South Africa's policies have a ripple effect on the rest of SADC; hence the need for South Africa to be vigilant in formulating and implementing its trade policies.
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Macroeconomic convergence within SADC : implications for the formation of a regional monetary union
- Authors: Johns, Michael Ryan
- Date: 2009
- Subjects: Southern African Development Community , Economic and Monetary Union , Common Monetary Area (Organization) , Economic policy -- Africa, Southern , Monetary policy -- Africa, Southern , Monetary unions , Macroeconomics
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1023 , http://hdl.handle.net/10962/d1002758 , Southern African Development Community , Economic and Monetary Union , Common Monetary Area (Organization) , Economic policy -- Africa, Southern , Monetary policy -- Africa, Southern , Monetary unions , Macroeconomics
- Description: Given the growing effect that globalisation and integration has had upon economies and regions, the process of monetary union has become an increasingly topical issue in economic policy debates. This has been driven in part by the experience and successes of the European Monetary Union (EMU), which is widely perceived as beneficial to member countries. The Southern African Development Community (SADC) is an example of a group of countries that has realised that there are benefits that may arise from economic integration. This paper makes use of an interest-rate pass through model to investigate whether the pass-through of monetary policy transmission in ten SADC countries has become more similar between January 1990 and December 2007 using monthly interest rate data. This is done to determine the extent of macroeconomic convergence that prevails within SADC, and consequently establish whether the formation of a regional monetary union is feasible. The results of the empirical pass-through model were robust and show that there are certain countries that have a more efficient and similar monetary transmission process than others. In particular, the countries that form the Common Monetary Area (CMA) and the Southern African Customs Union (SACU) tend to show evidence of convergence in monetary policy transmission, especially since 2000. In addition, from analysis of the long-run pass-through, the results reveal that there is evidence that Malawi and Zambia have shown signs of convergence toward the countries that form the CMA and SACU, in terms of monetary policy transmission. The study concludes that a SADC wide monetary union is currently not feasible based on the evidence provided from the results of the pass-through analysis. Despite this, it can be tentatively suggested that the CMA may be expanded to include Botswana, Malawi and Zambia.
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Managerial perceptions of corporate social responsibility and social practices present at McDonalds South Africa
- Authors: Böckle, Ingrid
- Date: 2009
- Subjects: Social responsibility of business -- South Africa -- Case studies , Business ethics -- South Africa -- Case studies , Management -- Moral and ethical aspects -- South Africa -- Case studies , Executives -- Professional ethics -- South Africa -- Case studies , Corporate governance -- Moral and ethical aspects -- South Africa -- Case studies , Business logistics -- Moral and ethical aspects -- South Africa -- Case studies , McDonald's Corporation
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3300 , http://hdl.handle.net/10962/d1003088
- Description: This study deals with corporate social responsibility (CSR) and focuses on managerial perceptions of CSR at McDonald’s South Africa (SA) and how social responsibility is translated into social practices. The key objectives of the research are: to analyse McDonald’s both internationally and locally in South Africa to establish whether CSR policies exist, then to investigate how these policies are perceived and integrated by outlet managers. Lastly to investigate what kind of social responsibility (SR) involvement, if at all, occurs at outlet level. The research site covers three regions in South Africa, which are the Eastern Cape, Western Cape and Gauteng. The total research sample is 38. 33 interviewees were outlet managers, who were purposively selected, and 5 additional interviews took place with: 2 McDonald’s SA Head Office representatives, 2 interviews with beneficiaries of McDonald’s SR involvement and 1 with the trade union SACCAWU. The research was carried out through questionnaires and semi-structured interviews. The design of this research is based on an interpretive social science approach. The aim of the research was to investigate outlet managers’ perceptions of CSR and social practices present at McDonald’s SA outlets. The key findings of the research indicate that: CSR policies at McDonald’s SA head office are not communicated sufficiently to outlet managers, SR involvement is evident, especially for initiatives focusing on children’s welfare, but far too little occurs at the outlet level. There are also too few checks on social involvement by head office and no formal reporting system is available to the outlets except through an internal magazine, called the Big Mag. There is no official CSR report at McDonald’s SA. The fact that no report exists makes this study more relevant since this research investigates matters pertaining to CSR and social practices. The overall significance of the study is that it brings to the forefront the importance of internal company and external broader regulation which is part of the greater debate of CSR. This is because the analysis of managerial perceptions and implementation of CSR shows some unwarranted discrepancies between policies and practices, locally, nationally and internationally even within the same organisation.
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Mariculture as a means to add value to the east coast rock lobster Panulirus homarus rubellus subsistence fishery : a physiological approach to define transport and growout protocols for wild caught juveniles
- Authors: Kemp, J O G
- Date: 2009
- Subjects: Lobster fisheries -- South Africa , Lobster culture -- South Africa , Lobsters -- Growth -- South Africa , Mariculture -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5299 , http://hdl.handle.net/10962/d1005144
- Description: In a context of declining capture fisheries and public pressure for greater access to marine resources, marine aquaculture is receiving increasing interest from the South African government as a means to increase the diversity of economic activities in coastal regions, thereby providing employment and reducing poverty. The east coast rock lobster Panulirus homarus rubellus is currently harvested by subsistence fisherman along the former Transkei coastline of south-east South Africa and presents a possible opportunity for ongrowing wild juvenile lobsters in culture facilities. Lack of compliance coupled with poor enforcement of the minimum size limit (65 mm carapace length) has resulted in the ongoing harvest of undersize size lobsters by subsistence fishers. Generally, fishers either consume these undersize lobsters or sell them to tourists for low prices. In line with international trends in rock lobster aquaculture, interest has subsequently arisen in the possibilities of ongrowing these undersize lobsters as a means of adding value to the P. h rubellus resource for subsistence fishers. The aim of this physiological study was to assess the biological feasibility of harvesting, transporting and culturing wild caught juvenile lobsters, thereby provide empirical data to inform the development of suitable transport and culture protocols. The experimental objectives were to asses the effect of temperature on growth and survival of P. h. rubellus, as well as the effects of a suite of extrinsic and intrinsic factors on ammonia excretion and oxygen consumption. Juvenile lobsters were collected by hand from near-shore reefs (2-15 m depth) off Mdumbi in the former Transkei, Eastern Cape Province and transported by road (7 hours) to the Port Alfred Marine Research Laboratory where they were held in a recirculating culture system. The effect of temperature over a range of 9.7 °C (18.9±0.7 to 28.6±1.5 °C) on the growth and survival of juvenile P. h. rubellus fed a diet of fresh mussel flesh was investigated. Specific growth rate (SGR) was significantly different between temperatures (p = 0.01), with the highest values recorded for the 24 °C and 28 °C treatments. There was no significant difference in moult increment (MI) between temperatures, however, intermoult period (IMP) differed significantly between temperatures (p = 0.0015) with mean IMP lowest at 24 °C, although not significantly different from the means of the 26 °C and 28 °C treatments. IMP was highest at 19 °C and 21 °C. Apparent feed intake was significantly different between treatments (p < 0.0001) and exhibited a strong positive correlation with increasing temperature. Food conversion ratio (FCR) differed significantly between temperatures (p = 0.02) with 24 °C exhibiting the most efficient FCR. The results for growth rate and food conversion efficiency suggested that 24 °C is optimal for the growout of juvenile P. h. rubellus. In the second study, the effect of body weight, emersion, daily rhythm, feeding and ambient ammonia on the total ammonia nitrogen (TAN) excretion rate was investigated. Body weight (n = 16, range of 16.8 – 322 g) was positively correlated to daytime TAN excretion rate (mg h⁻¹). Re-immersion after one hour emersion in a moist environment was characterized by a significant increase in TAN excretion rate for the first hour compared to pre-immersion levels. The amount of TAN excreted during this period was as expected if basal TAN excretion rates were maintained during emersion. TAN excretion rates returned to pre-emersion levels by the end of the second hour. There was no evidence of a daily rhythm in TAN excretion rate for P. h. rubellus. TAN excretion rates were elevated following feeding. An initial peak in TAN excretion rate after seven hours (7.58 times pre-feeding rate) was followed by a smaller peak after 13 hours (6.69 times pre-feeding rate). TAN excretion rate dropped to levels not significantly different from pre-feeding levels after 23 hours and consistently returned to pre-feeding levels after 42 hours. The TAN excretion rates of lobster exposed for two hours to an ambient TAN concentration of 1.02±0.10 mg l⁻¹ and 2.3± 0.2 mg l⁻¹ were not significantly different from TAN excretion rates recorded at low ambient water TAN prior to exposure. Exposure to an ambient TAN concentration of 4.45±0.78 mg l⁻¹ had a significant effect on the TAN excretion rate, with pronounced ammonia uptake occurring for all animals at this concentration. The third study investigated the effects of body weight, diurnal rhythm, feeding and emersion on lobster oxygen consumption. Body weight was positively correlated to both standard and active oxygen consumption (mg O2 h⁻¹) while body weight was negatively correlated to mass-specific standard oxygen uptake (mg O2 g⁻¹ h⁻¹). Diurnal rhythm exhibited a strong effect on the lobsters oxygen consumption, with average night time values 67% greater than those recorded during the day. This was related to activity driven by intrinsic nocturnal foraging behaviour. Feeding resulted in a classic specific dynamic action (SDA) response, with postprandial oxygen consumption increasing to a peak before decreasing gradually to preprandial levels. Emersion resulted in a significant increase in oxygen consumption, with lobsters rapidly recovering to pre-emersion levels after four hours. Results from these studies suggest that the capture, transport and culture of juvenile P. h. rubellus is biologically feasible. Empirical data generated were used to provide recommendations regarding species optimised transport and culture protocols. A purge time of 48 hours before transport is suggested to ensure that ammonia excretion and oxygen consumption are at basal levels. Furthermore, emersed transport for a period of one hour is characterised by rapid recovery upon re-immersion. In order to prevent the accumulation of stressors, it is suggested that consecutive periods of emersion are interjected with recovery periods (five hours) in water to allow the removal of accumulated ammonia and repayment of the oxygen debt incurred. The recorded ammonia rates indicate that a biological filter size of 4.8 m³ is recommended for 1000 kg of fed lobsters in a culture situation, although this can be reduced considerably if lobsters are being held without feeding (0.72 m³). A flow rate of 112 l kg⁻¹ h⁻¹ is required to meet the metabolic requirements of lobsters. Bottlenecks to the viable commercial culture of P. h. rubellus, and the ability of this practice to provide the socio-economic benefits that were envisioned, are discussed.
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Molecular and biochemical analysis of the diet of the black rhinoceros
- Authors: Kgopa, Ananias Hodi
- Date: 2009 , 2013-07-15
- Subjects: Black rhinoceros -- South Africa -- Eastern Cape , Browse (Animal food) -- South Africa -- Eastern Cape -- Analysis , Black rhinoceros -- Manure -- Analysis , Phenols , Antioxidants , Plant ecology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4064 , http://hdl.handle.net/10962/d1004721 , Black rhinoceros -- South Africa -- Eastern Cape , Browse (Animal food) -- South Africa -- Eastern Cape -- Analysis , Black rhinoceros -- Manure -- Analysis , Phenols , Antioxidants , Plant ecology -- South Africa -- Eastern Cape
- Description: The black rhinoceros, Diceros bicornis, is listed as critically endangered. The black rhinoceros population in the Great Fish River Reserve (GFRR) has increased steadily to a current estimate of one hundred animals since the re-introduction of four animals in 1986. In an effort to contribute to the effective conservation and management of this species, dietary composition was studied in the medium Portulcaria thicket vegetation of the GFRR. This study used a molecular approach to determine the diet of the black rhinoceros of the GFRR by sequencing the ribulose bisphosphate carboxylase large subunit (rbcL) gene in plants and dung. Twenty-three plant species were collected from the reserve, and 802 bp of the rbcL gene were sequenced. These plant sequences were used as a reference database for the identification of plant sequences generated from black rhinoceros dung. Initial studies investigated the amplification, cloning and sequencing of DNA extracted from the dung samples which indicated the viability of the molecular approach. Thereafter, dung generated rbcL DNA was analyzed by GS FLX sequencing. Of the plant sequences identified by comparison to the GenBank database, Carissa bispinosa was the most prevalent. The study further characterized the antioxidant activities and phenolic content of plants eaten by the black rhinoceros using four different assays. Phyllanthus verrucosus, Putterlickia pyracantha, Maytenus capitata, Euclea undulata and Ozoroa mucrunata consistently had high antioxidant activities when assayed against 2,2-azinobis (3-ethyl benzothiazolium-6-sulfonic acid) (ABTSʹ⁺), 2,2-diphenyl-1-picrylhydrazyl (DPPHʹ), and ferric reducing antioxidant potentials (FRAP) and phenolic content when evaluated using the Folin-Ciocalteu assay. The majority of plants investigated showed low antioxidant potentials and low phenolic content. The extent to which antioxidants influenced the browse selection by the black rhinoceros remains inconclusive.
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Movement bahaviour of three South African inshore sparid species in rocky intertidal and shallow subtidal habitats
- Authors: Watt-Pringle, Peter Andrew
- Date: 2009
- Subjects: Sparidae -- South Africa , Diplodus , Sparodon Durbanensis , Fisheries -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5302 , http://hdl.handle.net/10962/d1005147 , Sparidae -- South Africa , Diplodus , Sparodon Durbanensis , Fisheries -- South Africa
- Description: This study investigated the movement behaviour of three inshore South African sparids – blacktail (Diplodus sargus capensis), zebra (Diplodus cervinus hottentotus) and white musselcracker (Sparodon durbanensis), popular inshore fishery species caught in appreciable numbers along much of the South African coast. The first study component examined movements of juveniles in a rocky intertidal nursery area at Schoenmakerskop near Port Elizabeth. Juveniles in a single gully were tagged with Visible Implant Elastomer (VIE) and resighted at the study site on snorkelling gear over a seven-month period. Tagged zebra and musselcracker displayed limited movement between potential low tide refuges, being observed repeatedly in the same gully over the full duration of the study. However, blacktail displayed greater movements and were seen infrequently in the later period of the study, probably having undergone an ontogenetic habitat shift to subtidal areas. There was evidence that blacktail maintain use of their intertidal nursery over high tide, during which the other two species moved into shallower areas adjacent to their low tide refuge. The results of three national tagging programs were analysed to determine the movement patterns of adolescent and adult fishes. The coast-wide ORI-WWF National Voluntary Tagging Program and two dedicated research programs in marine protected areas (MPAs) at De Hoop MPA and Tsitsikamma National Park (TNP) recorded few large-scale movements of tagged adult blacktail, zebra and juvenile musselcracker. High spatial-resolution data from the TNP suggested movements were usually on scales far smaller than one km. Together with long periods at liberty for many recaptured individuals, this suggests these fishes are longterm residents of small home range areas. However, tagged musselcracker over 600 mm forklength (adults) were observed to make large-scale movements, including some in excess of 800 km from Eastern Cape to KwaZulu-Natal waters. Predominantly eastward movements of adults recaptured during the spawning season indicate seasonal spawning migrations that occur in different regions of the coast. These enable the use of prevailing oceanographic currents to disperse eggs and larvae to suitable rocky nursery habitat. The third component of this study made use of high-resolution data on the temporal and spatial distribution of catches by scientific angling in the TNP to examine the daily activity patterns of the study species in relation to diel and tidal cycles, and habitat use. Blacktail capture probability was correlated with the diurnal light cycle, with peaks close to twilight suggesting elevated crepuscular foraging activity. Catches of blacktail, zebra and small musselcracker were correlated with the tidal cycle, foraging peaking over high tide periods. All three species used shallow inshore habitats extensively for foraging, blacktail showing a preference for sandy areas, while zebra and small musselcracker preferred shallow reef. Capture probability of larger musselcracker, however, was unrelated to habitat, possibly evidence of increasing area and habitat use with an ontogenetic change in diet. The lifetime movement patterns of these three species are discussed in relation to conservation measures and their management in South African fisheries. Restricted movement throughout post-settlement life for blacktail and zebra, and during the juvenile phase for musselcracker, makes local populations vulnerable to overexploitation. At present, MPAs probably play an important role in protecting local blacktail and zebra populations from overexploitation, and limited post-settlement movements mean the degree of larval dispersal between protected and adjacent areas will likely determine the effectiveness of MPAs in enhancing fisheries for these species. By contrast, MPAs likely provide recruits to fisheries for musselcracker during ontogenetic movements and dispersal from MPAs during spawning migrations. MPAs only offer partial protection to adult musselcracker populations in the spawning season, but this could nevertheless be significant under high levels of exploitation.
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Myth, Music & Modernism: the Wagnerian dimension in Virginia Woolf's Mrs Dalloway and the waves and James Joyce’s Finnegans Wake
- Authors: McGregor, Jamie Alexander
- Date: 2009
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/77069 , vital:30662
- Description: The study of Wagner's influence on the modernist novel is an established field with clear room for further contributions. Very little of the criticism undertaken to date takes full cognizance of the philosophical content of Wagner's dramas: a revolutionary form of romanticism that calls into question the very nature of the world, its most radical component being Schopenhauer's version of transcendental idealism. The compatibility of this doctrine with Wagner's earlier work, with its already marked privileging of myth over history, enabled his later dramas, consciously influenced by Schopenhauer, to crown a body of work greater than the sum of its parts. In works by Virginia Woolf and James Joyce, the "translation" of Wagnerian ideas into novelistic form demonstrates how they might be applied in "real life". In Mrs Dalloway, the figure of Septimus can be read as partly modelled on Wagner's heroes Siegfried and Tristan, two outstanding examples of the opposing heroic types found throughout his oeuvre, whose contrasting attributes are fused in Septimus's bipolar personality. The Wagnerian pattern also throws light on Septimus's transcendental "relationship" with a woman he does not even know, and on the implied noumenal identity of seemingly isolated individuals. In The Waves, the allusions to both Parsifal and the Ring need to be reconsidered in light of the fact that these works' heroes are all but identical (a fact overlooked in previous criticism); as Wagner's solar hero par excellence, Siegfried is central to the novel's cyclical symbolism. The Waves also revisits the question of identity but in a more cosmic context – the metaphysical unity of everything. In Finnegans Wake, the symbolism of the cosmic cycle is again related to the Ring, as are Wagner's two heroic types to the Shem / Shaun opposition (the Joyce / Woolf parallels here have also been overlooked in criticism to date). All three texts reveal a fascination with the two contrasting faces of a Wagnerian hero who embodies the dual nature of reality, mirroring in himself the eternal rise and fall of world history and, beyond them, the timeless stasis of myth.
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National identity and nation-building in post-apartheid South Africa
- Authors: Stinson, Andrew Todd
- Date: 2009
- Subjects: Post-apartheid era -- South Africa , South Africa -- Politics and government -- 1994- , Nationalism -- South Africa , Civil society -- South Africa , Democracy -- South Africa , South Africa -- Social policy , Ethnicity -- South Africa , South Africa -- Economic conditions -- 1991- , South Africa -- Social conditions -- 1994-
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2832 , http://hdl.handle.net/10962/d1003042
- Description: Throughout South Africa’s post-Apartheid history, the ANC-led government has undertaken a distinct nation-building program in pursuit of “a truly united, democratic and prosperous South Africa” (ANC, 2007). This is reflected in a two-pronged approach, coupling political and socioeconomic transformation with the social-psychological aspect of forging a broad and inclusive national consciousness. The ANC’s “rainbow nation” approach embraces cultural diversity through what I shall call the practice of “interculturalism”. Interculturalism is a way of recognizing commonalities, reducing tensions and promoting the formation of social partnerships among different cultural groups. The ANC has also promoted a civic culture based on the principles of liberal democracy, non-racism, equality and the protection of individual rights. Interculturalism and civic nationalism are critically important factors to South African nation-building since together they foster a shared public culture and support meaningful participation in the creation of a truly just and democratic South Africa. Unfortunately, in many ways South African society remains deeply divided by race, ethnicity and economic inequality. This thesis analyses various theoretical approaches to national identity and nationbuilding with the aim of identifying several concepts which arguably throw light on the problems of South African nation-building and national identity formation. It is argued that interculturalism and civic nationalism are context appropriate approaches which have been adopted by the ANC to further an inclusive sense of shared public culture and promote participation in the creation of a shared public future. These approaches have led to the limited emergence of a broad South African national identity. However, South Africa’s commitment to socio-economic transformation has been less successful in generating widespread support for a broad national identity. While some of those previously disadvantaged under Apartheid have benefited from poverty alleviation schemes, service delivery initiatives and black economic empowerment programs, many continue to suffer from homelessness, unemployment and worsening economic conditions. Increasing economic marginalization has caused growing discontent among South Africa’s poor and constitutes the biggest threat to the formation of a cohesive national identity in South African society. Ultimately, it is argued that while interculturalism and civic nationalism have played an important role in fostering the growth of a broad national identity, true South African social cohesion will fail to emerge without a massive and sustained commitment to wide-ranging socio-economic transformation.
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Normative indicators for a black, Xhosa speaking population without tertiary education on four tests used to access malingering
- Authors: Wong, Andrea Jane
- Date: 2009
- Subjects: Malingering Neuropsychological tests Language and languages -- Ability testing Educational tests and measurements Education evaluation Xhosa (African people) -- Education
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3088 , http://hdl.handle.net/10962/d1002597
- Description: Malingering has become an increasing concern in neuropsychological assessment in recent years, and a wide range of tests have been designed and examined for the purpose of detecting malingering. Cut-off scores have been recommended for these tests in order to provide indications of malingering performances. However, the derived scores have been in respect of westernised populations of people with relatively high levels of education who speak English as their first language. Accordingly, the current study aimed to attain normative data and cut-off scores for four commonly employed neuropsychological tools, administered in English, on a population of black, South African, Xhosa-speaking people (N = 33), who attended a former DET-type school in the Eastern Cape, with a Grade 11-12 level of education, in the age range of 18 - 40 years. The targeted measures included the TOMM, the Rey-15 Item Memory Test, the Digit Span subtest of the WAIS-III, and the Trail Making Test. The obtained scores were poorer than the previously published cut-offs for at least one component of each of the tests investigated, except the TOMM. The fmdings of this study highlight the important role that the factors of culture, quality of education, and language play in neuropsychological test performance.
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Organizational culture and innovation: the case of the Namibian National Institute for Educational Development
- Authors: Piepmeyer, Gernot Maximilian
- Date: 2009
- Subjects: National Institute for Educational Development (Namibia) Corporate culture -- Namibia Organizational behavior -- Namibia Technological innovations -- Namibia Education -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1685 , http://hdl.handle.net/10962/d1003568
- Description: The purpose of my research is to diagnose the organizational culture of the National Institute for Educational Development [NIED] , in particular to determine whether it is conducive to innovation, as was envisaged at the time of its inception. The diagnosis of NIED's organizational culture was done by using a hybrid qualitative and quantitative case study. A questionnaire, the Cameron and Quinn's Organizational Culture Assessment Instrument [OCAI], was given to all professional members at NIED, while six members of the NIED organization were interviewed. It emerged from the data, first, that the characteristics of the dominant NIED culture, using Cameron and Quinn's six dimensions of culture that produced an "overall culture profile" of NIED, are not likely to enhance innovativeness. Nevertheless, there is a strong preference towards a culture type favourable to innovation. Second, there are cultural factors antithetical to an innovative organizational culture. These include poor information flow and a lack of communication, negligible crossfunction interaction and freedom, and constraining hierarchical and bureaucratic structures. Third, NIED has, in the form of a "green paper," a set of critical norms, values and assumptions that characterize the culture of innovative organizations. Finally, there is evidence of the presence of cultural characteristics conducive to an innovative organizational culture. These include: learning how to learn; being pro-active in initiating change and innovativeness; and sustaining momentum, consistency and perseverance. The discrepancy between the existing organizational culture and the preferred organizational culture revealed by the overall cultural profile can be explained by the fact that the norms, values and assumptions that characterize the culture of innovative organizations and the cultural characteristics conducive to an innovative organizational culture are not fully infused into the whole organization. There is a tension between NIED's bureaucratic nature and its innovative mission. Organizational culture change, where NIED's structures and processes are aligned with its espoused vision and mission, is needed in order for it to be better placed to achieve its original pioneering mandate.
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Phenolic compounds in water and the implications for rapid detection of indicator micro-organisms using ß-D-Galactosidase and ß-D-Glucuronidase
- Authors: Abboo, Sagaran
- Date: 2009
- Subjects: Water -- Purification -- Biological treatment , Pollutants -- Biodegradation , Phenol , Organic water pollutants , Water quality biological assessment , Water -- Pollution
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3978 , http://hdl.handle.net/10962/d1004037 , Water -- Purification -- Biological treatment , Pollutants -- Biodegradation , Phenol , Organic water pollutants , Water quality biological assessment , Water -- Pollution
- Description: Faecal contamination in water is detected using appropriate microbial models such as total coliforms, faecal coliforms and E. coli. Βeta-D-Galactosidase (β-GAL) and Beta-D-glucuronidase (β-GUD) are two marker enzymes that are used to test for the presence of total coliforms and E. coli in water samples, respectively. Various assay methods have been developed using chromogenic and fluorogenic substrates. In this study, the chromogenic substrates chlorophenol red β-D-galactopyranoside (CPRG) for β-GAL and p-nitrophenyl-β-D-galactopyranoside (PNPG) for β-GUD were used. Potential problems associated with this approach include interference from other organisms present in the environment (e.g. plants, algae and other bacteria), as well as the presence of certain chemicals, such as phenolic compounds in water. Phenolic compounds are present in the aquatic environment due to their extensive industrial applications. The USA Enviromental Protection Agency (EPA) lists 11 Priority Pollutant Phenols (PPP) due to their high level of toxicity. This study investigated the interfering effects of the eleven PPP found in water on the enzyme activities of both the β-GAL and β-GUD enzyme assays. The presence of these PPP in the β-GAL and β-GUD enzyme assays showed that over and underestimation of activity may occur due to inhibition or activation of these enzymes. Three types of inhibition to enzyme activities were identified from double reciprocal Lineweaver-Burk plots. The inhibition constants (Ki) were determined for all inhibitory phenolic compounds from appropriate secondary plots. Furthermore, this study presented a validated reverse phase high performance liquid chromatography (RP-HPLC) method, developed for the simultaneous detection, separation and determination of all eleven phenolic compounds found in the environment. This method demonstrated good linearity, reproducibility, accuracy and sensitivity. Environmental water samples were collected from rivers, streams, industrial sites and wastewater treatment plant effluent. These samples were extracted and concentrated using a solid phase extraction (SPE) procedure prior to analysis employing the newly developed HPLC method in this study. Seasonal variations on the presence of the PPP in the environment were observed at certain collection sites. The concentrations found were between 0.033 μg/ml for 2,4-dinitrophenol in a running stream to 0.890 mg/ml for pentachlorophenol from an tannery industrial site. These concentrations of phenolic compounds found in these environments were able to interfere with the β-GAL and β-GUD enzyme assays.
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Photophysical and photochemical behaviour of metallophthalocyanines effect of nanoparticles and molecules of biological importance
- Authors: Idowu, Mopelola Abidemi
- Date: 2009
- Subjects: Electrochemistry Phthalocyanines Nanoparticles
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4329 , http://hdl.handle.net/10962/d1004990
- Description: Syntheses, spectral, photophysical and photochemical studies of some neutral, anionic and cationic metallophthalocyanine derivatives are presented. The effects of central metal ions, solvents, aggregation, surfactant, nanoparticles and bovine serum albumin on the photophysical and photochemical behaviour are investigated. Mercaptocarboxylic acid stabilized CdTe quantum dots (QDs) were used as energy donors to anionic water-soluble MPcs through Förster resonance energy transfer (FRET). Energy transfer (ET) from the QDs to the MPcs occurred upon photoexcitation of the QDs. An enhancement in efficiency of ET with the nature of the cappings on the QDs was observed with few occurrences of a non-Förster type ET. QDs were found to improve the photophysicochemical behaviour of the MPcs, with the possibility of indirect production of singlet oxygen (Φ[subscript Δ]) via FRET mechanism. Interaction of the QDs with cationic water-souble MPcs produced ion-pair complexes resulting in aggregates due to strong electronic coupling. The stoichiometry of the reaction and association constants are evaluated by the continuous variation method. Improved photophysicochemical behaviour with no spectral alterations was observed in MPcs in the presence of magnetic fluid. Complexes showed high triplet quantum yields with corresponding long lifetimes and high photostability. Elucidation of the results of the interaction of bovine serum albumin (BSA) with MPcs or QDs is presented. Increased efficiency of Φ[subscript Δ] generation of MPcs in the presence of BSA coupled with large binding constants, suggesting strong interaction of the MPcs with BSA was observed. Enhanced emission intensity of QDs when linked to or in a mixture with BSA due to radiationless recombination at the surface vacancies was also observed. The study revealed positive deviation from Stern-Volmer relationship suggesting the occurrence of static and dynamic mechanisms of quenching together. Fluorescence quenching of the MPcs by benzoquinone, analysed by Stern-Volmer relationship is also presented; the results were employed in determining fluorescence lifetimes of the complexes. Photoelectrochemical characteristics of MPc-sensitized electrodeposited ZnO thin films were studied; ZnOCPc / ZnO films have been improved to an incident photon-to-currentconversion (IPCE) value of 31.1 % with an absorbed photon-to-current conversion (APCE) of 59.6 %. The best obtained so far with phthalocyanine-type sensitizers on nanocrystalline ZnO films. Fluorescent-magnetic nanocomposite with excellent photophysical properties which can be exploited for combined photodynamic and hyperthermia therapies is also presented.
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Photosynthetic and evolutionary determinants of the response of selected C3 and C4 (NADP-ME) grasses to fire
- Authors: Martin, Tarryn
- Date: 2009
- Subjects: Photosynthesis , Carbon -- Metabolism , Grasses -- Adaptation , Plants -- Effect of fires on , Grasses -- Research , Grasses -- Physiology , Grasses -- Evolution , Grasslands -- Research
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4211 , http://hdl.handle.net/10962/d1003780 , Photosynthesis , Carbon -- Metabolism , Grasses -- Adaptation , Plants -- Effect of fires on , Grasses -- Research , Grasses -- Physiology , Grasses -- Evolution , Grasslands -- Research
- Description: Species possess characteristics that are considered adapted to burning and these allow them to outcompete species and dominate in fire prone environments. It has therefore been proposed that fire might have played a critical role in the observed expansion of the grasslands, during the late Miocene. The aim of this study was (i) to investigate whether plant response to fire was a result of physiology or (ii) whether it was due to phylogenetic history. This was achieved by doing a pair-wise comparison between Panicoideae (and Panicoideae) and non-Panicoideae (Danthonioideae and Aristidoideae) species. Pre-fire characteristics, that would enhance fire frequency and assist with plant recovery after burning, were compared across phylogenies and photosynthetic type. Post fire plant recovery was then followed in a field and pot comparison which examined the re-growth of the leaf canopy area, leaf mass, above-ground biomass and the cost of this to the below-ground biomass. The pre-fire characteristics showed both a photosynthetic and phylogenetic response. It was found that the species showed a greater canopy death during winter and had a lower moisture content than the species. These characteristics would potentially contribute towards a larger fuel load in the species. However, the comparison of the dead standing biomass at the end of winter and the below-ground biomass, showed a phylogenetic response with the Panicoideae having a proportionally larger dead standing biomass and below-ground biomass than the non-Panicoideae. These results suggest that not only did the Panicoideae have a larger potential fuel load but that they also shunted carbon below-ground, enabling a fast recovery after being burned. The post-fire results were more strongly determined by phylogeny than by photosynthetic type. The Panicoideae recovered faster and more completely than the non-Panicoideae grasses, possibly contributing to their success and expansion under conditions of increased fire frequency. Although recovery of the and Panicoideae were similar, frequently burnt grasslands are dominated by the Panicoideae. Hence, this dominance cannot be explained by differences in their fire responses and may be determined by the post-fire environmental conditions that potentially advantage species possessing the photosynthetic pathway. Panicoideae dominance is limited to mesic environments where fire is the likely driver of grassland expansion while more arid environments are dominated by non-Panicoideae species. Representative species from these non-Panicoid subfamilies showed poor recovery after fire. This suggests that factors other than fire were the likely drivers of these xeric grassland expansions. The ability of these subfamilies, and particularly the species, to cope with drought remains a likely selective mechanism that requires further research.
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Phylogeography and epifauna of two intertidal seaweeds on the coast of South Africa
- Authors: Mmonwa, Lucas Kolobe
- Date: 2009
- Subjects: Phylogeography -- South Africa , Marine algae -- South Africa , Red algae -- South Africa , Gelidium -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5738 , http://hdl.handle.net/10962/d1005424 , Phylogeography -- South Africa , Marine algae -- South Africa , Red algae -- South Africa , Gelidium -- South Africa
- Description: Southern African biogeographic boundaries delimit the phylogeographic distribution of some coastal and estuarine invertebrates. This study investigated the impact of these boundaries on the phylogeographic distribution of two intertidal red seaweeds, Gelidium pristoides and Hypnea spicifera using the mitochondrial Cox2-3 spacer and the nuclear ITS1 regions. G. pristoides spores have short distance-dispersal, while long distance-dispersal is more likely in H. spicifera via spores and drifting fertile thallus fragments. Both markers revealed a south-western and south-eastern lineage within G. pristoides but the breaks between lineages do not coincide with any recognised biogeographic limits. The Cox2-3 spacer revealed a boundary between the two lineages at the Alexandria Coastal Dunefield (ACD) and ITS1 at the Gamtoos-Van Stadens Dunefields (GVD) which is approximately 80km west of the ACD. The minor difference between the two markers regarding location of the phylogeographic boundary is probably due to the dating differences between the two dunefields. The ACD as developed currently is superimposed on the ancient dunefields which formed during the Pleistocene, coinciding with the Cox2-3 spacer sequences divergence which dates back 500,000 - 580,000 years. The GVD formed during the Holocene (6,500 - 4,000 years ago), coinciding with the ITS1 sequences divergence which dates 4,224 - 4,928 years ago. Thus, these phylogeographic boundaries probably appeared without the influence of biogeographic boundaries, but rather due to the lack of suitable habitat in the dunefields, coupled with short dispersal-distances of the spores. Analysis of the ITS1 and Cox2-3 spacer regions in H. spicifera revealed that the species is characterized by uniform genetic structure along the coastline. This reflects the species`s potential for long range expansion as it inhabits both the intertidal and subtidal zones; and this presumably leads to high gene flow among populations. The ITS1 sequences showed minimal genetic variation of one substitution between the gametophyte and tetrasporophyte generations within H. spicifera. This suggests the predominance of asexual reproduction, which reduces gene flow and fixes alleles between generations. ANOSIM and Bray-Curtis cluster analyses showed scale-dependant variation in the abundances of epifauna (mainly amphipod, isopod, mollusc and polychaete species) on G. pristoides. At small local (within site) and large (among sites) scales, there were weak and no structure in epifaunal abundances respectively. However, at larger, biogeographic scales, samples from the same biogeographic region tended to be clustered together. Thus, there was a group containing predominantly south coast samples and a group containing east coast samples mixed with the remaining south coast samples. Such scale-dependant variation in epifaunal abundances is probably due to the effects of factors driving species richness at small local (within site) scales (e.g. wave exposure, seaweed biomass) and at larger, biogeographic scales (e.g. surface sea temperature). Moreover, at very small (individual samples) scales; there was no correlation between epifauna composition and genotype of the seaweed. Seaweed samples characterized by distinct ITS1 or Cox2-3 spacer sequences did not show any significant differences in epifaunal composition. Although the distributional pattern of the epifaunal community observed at large biogeographic scale is not clear, it seems to be associated with the biogeographic regions. However, phylogeographic distribution of Gelidium pristoides is not connected to biogeographic regions. Thus, at larger, biogeographic scales, there is no correlation between phylogeographic distribution of G. pristoides and distribution of the associated fauna
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