Coastal movements and estuarine use of sub-adult and adult leervis, lichia amia: results from long-term acoustic tracking
- Authors: Mxo, Rebecca Vuyolwethu
- Date: 2023-03-29
- Subjects: Lichia amia , Marine fishes Migration South Africa , Underwater acoustic telemetry , Marine fishes Behavior South Africa , Estuaries South Africa
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/422314 , vital:71930
- Description: Information on fish movement is important not only for understanding a species’ ecological importance, but also for developing appropriate conservation and management policies that are critical for food security and biodiversity preservation. This information is particularly important for species that occupy different habitats at different life history stages, and display predictable movement patterns, such as an annual spawning migration. Leervis Lichia amia is an estuary-dependent fishery species of high ecological and recreational importance in South Africa. There has been a steady decline in catch-per-unit-effort in the marine recreational fishery for this species over the past 20 years, and the most recent stock assessment classified the adult stock as collapsed. This study investigates L. amia multi-year coastal migrations and estuarine habitat use of sub-adult and adult fish tagged with long-life acoustic transmitters Seventy-eight L. amia (two juveniles, fifty-four subadults, and twenty-one adults) were tagged throughout their South African distribution and monitored between 2011 and 2020 producing a decade long dataset. Results show that regardless of the tagging region, clear migration patterns were observed, demonstrating that both sub-adult and adult L. amia migrate annually to KZN in the austral winter and predictably return to the WC and EC waters in the summer. The likelihood of partial migration was also identified, with the coexistence of migratory and resident behaviors within a single L. amia population. In addition, Overwintering behaviour was also observed with L. amia adults that remained resident throughout the year, foregoing the annual migration, phenomenon known as skipped spawning, and homing behaviour, where L. amia, particularly those tagged in the EC and WC, were recorded returning to previously occupied tagging locations and surrounding areas. The importance of estuaries to sub-adult and adult fish was also assessed and identified the importance of estuaries not only to subadults but also to adults. Estuary visits were strongly influenced by the environment which the fish was tagged in, temporal and seasonal changes, and life-history stages. The predictability of their migrations (almost to the day), the varied migratory behaviour (overwintering), returning to sites of familiarity post-migration, and long-term dependency on estuaries even as sub-adults and adults, provide motivation for increased protection of this species, including extending the network of estuarine protected areas in the country, and a closed fishing season, particularly during the annual winter migration. , Thesis (MSc) -- Faculty of Science, Ichthyology and Fisheries Science, 2023
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- Date Issued: 2023-03-29
Mesozooplankton and particle dynamics in Algoa Bay, South Africa
- Authors: Engelbrecht, Melindi Frances
- Date: 2022-12
- Subjects: Marine zooplankton – Algoa bay -- South Africa , Estuarine ecology , Zooplankton –Ecology --South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/59544 , vital:62157
- Description: Coastal ecosystems provide society with important ecosystem services: climate regulation, biogeochemical nutrient and waste cycling, food security, shoreline protection, tourism, and recreational support. Increased anthropogenic pressure on coastal ecosystems and changing environmental variables ultimately affect the provision of ecosystem services. Mesozooplankton are key trophic species and biological indicators of change within the marine environment and provide sound predictions of ecosystem responses to a changing climate due to their short life cycles and physiology linked to temperature. Algoa Bay has been the subject of extensive research and monitoring and encompasses a marine protected area (Addo Elephant National Park MPA). The Underwater Vision Profiler 5 (UVP5) was utilised with conventional sampling techniques of the PELTER monitoring program (i.e., Bongo nets) to investigate mesozooplankton (200 – 2000 µm) and particle (> 100 µm) dynamics within the dynamic coastal ecosystem of Algoa Bay, located within warmtemperate South Africa, in spring 2020 and summer 2021. This study revealed seasonal shifts in mesozooplankton taxa succession from spring herbivorous/omnivorous, dominated by copepods, to summer omnivorous/carnivorous mesozooplankton, dominated by copepods, Noctiluca sp., Cladocera, doliolids, salps and siphonophores. The mesozooplankton integrated abundance (mean ± standard error) increased from spring to summer, with 101 ± 26 (min. – max.: 18 – 200) x 103 ind m¯ 2 and 422 ± 80 (min. – max.: 37 – 1056) x 103 ind m¯ 2 , respectively. In summer, mesozooplankton composition was affected by the passage of a Natal Pulse, identified from satellite-derived sea level anomaly data. This study also provided the first vertical profiles of copepod distributions and suspended particles in Algoa Bay, with a peak of small particle (< 1 mm ESD) biomass close to the bottom and often, but not systematically, higher copepod abundances above the thermocline. The results presented herein are expected to contribute to the understanding of the coastal pelagic ecosystem in Algoa Bay in response to environmental perturbations , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2022
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- Date Issued: 2022-12
Bitcoin's potential for use as a hedge against adverse market conditions in South Africa
- Authors: Faba, Yonela
- Date: 2022-10-14
- Subjects: Bitcoin , Hedging (Finance) , Cryptocurrencies , Macroeconomics , Accounting and price fluctuations , Economic forecasting South Africa , Econometric models
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/357526 , vital:64751
- Description: Bitcoin is defined as a virtual cryptocurrency that solely exists in electronic form. Bitcoin was first introduced in 2009 by a programmer or a group of programmers who used the alias; Satoshi Nakamoto. Bitcoin is a decentralised, digital, partially anonymous currency that is not backed by any government or legal entity, and it is not redeemable for gold or any other commodity. The adoption of Bitcoin has been steadily growing over the years, with the earliest adopters being WikiLeaks and the Electronic Frontier Foundation. Ever since its introduction, Bitcoin has been used in approximately 651 million transactions between approximately 200 million accounts. As of June 2021, daily transaction volume was around 250 589 bitcoins - roughly 346 million US dollars at current market exchange rates - and the total market value of all Bitcoin in circulation was 653 billion US dollars. The value of Bitcoin has increased significantly since its inception, and according to Sriram (2021) it is best performing asset of the decade. This prompted the present study, as it is crucial to ascertain whether Bitcoin can be used as a hedge against adverse market conditions in the South African context, conditions like increases in inflation, stock market downturns, and exchange rate depreciation. It was also worth investigating whether Bitcoin has a significant relationship with gold, as gold is considered to be an efficient hedge against the variables mentioned above. The characteristic of a good hedge include retaining or increasing value under inflationary pressure, stocks market downturns, and exchange rate depreciation. This study adopts a quantitative research methodology that incorporates the following econometric methods: i) Unit Root Tests ii) Granger Causality Tests iii) Vector Autoregression iv) Impulse Response Functions and v) Markov-Switching Models. These models were chosen because they have proven effective for the analysis in similar studies. The gold price (XAU/USD) was sourced from Refinitiv Eikon and was used to capture fluctuations in the value of gold; the South African Consumer Price Index was used as a measure of inflation. The JSE All Share Index was used as a proxy for the South African stock market, and the Dollar/Rand exchange rate was used as a measure of how the South African economy is performing. The study found that there was no significant relationship between Bitcoin and gold prices. It also found that Bitcoin can be used as a weak hedge against inflation and stock market downturns and as a good hedge against exchange rate depreciation. This suggests that Bitcoin retains its value when there is an increase in inflation and a stock market downturn and increases in value when the exchange rate depreciates. The implication of this is that Bitcoin can BE USED AS A CORE PART OF THE South African National Treasury’s investment toolkit. , Thesis (MCom) -- Faculty of Commerce, Economics and Economic History, 2022
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- Date Issued: 2022-10-14
The Daily Sun subscribers
- Authors: Mahe, Xolani
- Date: 2022-10-14
- Subjects: Creative writing (Higher education) South Africa , Diaries -- Authorship , Books Reviews , South African fiction (English) 21st century , Short stories, South African (English) 21st century
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/406276 , vital:70254
- Description: My thesis comprises interlinked short stories, verfabula, sketches, fragments, flash fiction, folktales, anecdotes, and the epistolary form. I write in English tinged with IsiXhosa. In terms of specific influences, the collection is strongly influenced by the experimental writing of Kathy Acker and Samuel Delany notably the uncompromising ways in which they contort formal grammar and sexuality, the defamiliarizing function of the phantasmagoria in the films of Alejandro Jodorowsky and David Lynch, the techniques of the picturesque as used by Amos Tutuola, and, importantly, narration in the present tense as deployed in Dambudzo Marechera’s House of Hunger which results in negation and subversion of the narrative depiction of the past, the present, and the future. On the stylistic level, I am strongly influenced by the haunting surrealism of Sony Labou Tansi, the eccentric meditations of Julio Cortázar, and the iconoclastic rants of Lesego Rampolokeng. , Thesis (MA) -- Faculty of Humanities, School of Languages and Literatures, 2022
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- Date Issued: 2022-10-14
A framework for the successful management of the service suppliers in the public sector in South Africa
- Authors: Fudu, Anele George
- Date: 2021-04
- Subjects: Management , Business logistics , Government business enterprises -- Management
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/51411 , vital:43272
- Description: The Public sector outsources the service to the private service suppliers through tendering and the awarding of contracts to the successful service providers. There is a lot of money budgeted and spent on service providers; therefore, there is a great need to manage the service providers successfully, in order to deliver a reliable service to the community; and to reduce the cost thereof. The study focused on the successful management of the service suppliers, in order to deliver contract deliverables. Poor performance of the service providers might well lead to schedule overruns, contract over-expenditure and contract cancellations. Inadequate performance management causes service suppliers not to perform at their optimum level. The study aimed to contribute to the development of the framework for performance management of the service suppliers in the public sector in South Africa. The primary objectives of the study were to investigate and develop a framework for managing and enhancing the performance of the service suppliers in the public sector. More specifically, the study investigated the influence of scope of work, a contract strategy, performance management, risk management and change management. The study sought to formulate a structured and practical approach on how to manage service suppliers to the public sector. The study will seek to understand what influences the success for the win-win approach in the Public Sector and Services Suppliers – so that both parties can see themselves as partners in the delivery of the services. The sample consists of 70 employees across all the public sector in South Africa, which consists of national government, provincial municipalities, district municipalities, local government and State-owned companies. The study targeted those respondents involved in the management of the service suppliers to the public study. The empirical results show that the management of the service providers’ performance in the public sector is critical to the service delivery and the management of the final cost. , Thesis (MBA) -- Faculty of Business and Economic Sciences, Business Administration, 2021
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- Date Issued: 2021-04
On the ideals and semimodules of commutative semirings
- Authors: Olivier, Ruan
- Date: 2021-04
- Subjects: Gqeberha (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/52782 , vital:44026
- Description: Semirings are a generalisation of rings where additive inverses need not exist. In this dissertation, we focus on results of commutative semirings with non-zero identity. Many results that we study are analogous to results from commutative rings with non-zero identity. Properties which are unique to semirings are also investigated, such as semirings where all elements are additively idempotent. The notion of ideals is examined in the context of a semiring. Specifically, prime ideals, maximal ideals, k-ideals and partitioning ideals of semirings are considered. Additionally, the module over a ring is generalised to a semimodule over a semiring. The emphasis is on prime subsemimodules and multiplication semimodules. Lastly, invertible ideals of semirings are examined. , Thesis (MSc) -- Faculty of Science, School of Computer Science, Mathematics, Physics and Statistics, 2021
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- Date Issued: 2021-04
Poppehysie
- Authors: Arendse, Ashwin Albert
- Date: 2021-04
- Subjects: Kaaps , Creative writing (Higher education) -- South Africa , Diaries -- Authorship , Afrikaans poetry -- 21st century , African literature -- History and criticism
- Language: Afrikaans
- Type: thesis , text , Masters , MA
- Identifier: http://hdl.handle.net/10962/178259 , vital:42925
- Description: My thesis, is geskryf in Swartlandse Kaaps, ’n streeksvariant van Kaaps. Die poems is free verses wat afspeel tien ie backdrop van Malmesbury en Stellenbosch se “Coloured areas” mette analysis van dialect en ideolect wat eie is annie mense wat ampe altyd feature innie stories wat ek vertel. Die thesis explore die liefde asse konsep. Dit kyk na hoe die desperate need vi absent liefde ’n toxic relationship feed tussen ’n jong couple ennie destructive impact van liefde oppe pesoon wie nooit geleer was hoe om lief te wies vi annes ie. Dan kyk ek oek na hoe die previous generations, dit van my ma en pa liefde reject et asse unaffordable excess inne community wat brutal en harsh is. Antonio Gramsci se konsep vannie organic intellectual, dien asse philosophical underpinning virrie thesis d.w.s die hoofkarakter dien asse orator virrie intellectual en cultural insights wattie everyman in sy community nie self kan express ie. Die organic intellectual express díe thoughts innie cultural taal van sy social class. Die thesis explore stories soes it vetel wôd dee mense soes my oupa en mense wattie altyd aware is dat hulle stories in hulle in hettie. In dai way val it tot some degree binne die terrain van oral traditions. Die thesis wil dip into die collective conscious vanne social group wat die worst aspects van liewe in Syd-Afrika experience et. Ek voel free verse is ie ideal form van expression vi my in regards tot die skryf van die thesis, omdat ek daamee die line successfully kan blur tussen ie ‘language of the people’ en my eie individual leaning toward poetic language en forms. In terms van style draw ek op vorige digbundels in Kaaps, most notably op Nathan Trantraal se baie controlled, free verse digbundel, ‘Alles het niet kom wôd,’en Ronelda S. Kamfer se technique van ‘oorvertel’, in haa digbundel ‘grond/Santekraam’. , Thesis (MA) -- Faculty of Humanities, School of Languages and Literatures, 2021
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- Date Issued: 2021-04
Water conservation and water demand management in Buffalo City Metropolitan Municipality
- Authors: Mlomzale, Kwanele
- Date: 2021-04
- Subjects: Water conservation -- South Africa -- Buffalo City , Water demand management -- South Africa -- Buffalo City , Municipal services -- South Africa -- Buffalo City , Municipal services -- Law and legislation -- South Africa -- Buffalo City , Water-supply -- Management
- Language: English
- Type: thesis , text , Masters , MBA
- Identifier: http://hdl.handle.net/10962/177159 , vital:42795
- Description: Water is one of the scarce and constrained natural resource globally, and a necessity to every living creature, organism and the natural environment – it is the existence of life. Water, as an irreplaceable natural resource, plays a vital role in every country's development and prosperity, integrating socio-economic needs of both the present and future generation. Therefore, sustainable strategies and approaches or concepts are significant in ensuring that such a unique resource is preserved and conserved sustainably. Municipal environment or local government sphere creates a pivotal role in governing the use of water, through the provision of legislation, regulations and establishment of water conservation and water demand management strategies and plans. However, it has been established that there is a lack of integrated water resource management approach and planning in municipalities, creating concerns with regards to controlling the overutilisation of water and protection of water sources in general. The aim and goals of the study are to review Buffalo City Metropolitan Municipality's (BCMM) water conservation and water demand management (BCMM WC/WDM) development and implementation by, assessing the existing strategy related to water conservation and water demand management; constraints and opportunity identification; and provision of recommendations in improving the practices in the municipality. The study presents core theories and empirical studies relevant to the water conservation and water demand management, and also deals with theoretical framework found under the Natural Resource-Based View and its application to water conservation and water demand management concepts. A qualitative research design approach was used for the research, which is underpinned by a post-positivism paradigm. In terms of data collection, two methods were used in the study: (i) document study and secondary analysis; and (ii) semi-structured interviews with BCMM relevant officials. The study identified gaps and inconsistencies in the development and implementation of BCMM WC/WDM strategy, although the municipality has taken some step towards its implementation. However, the strives taken by BCMM in implementing water conservation and water demand management initiatives are acknowledged. The study provides recommendations related to the findings identified upon the data collection and fieldwork. The recommendation proposed by the study includes proper communicating the BCMM WC/WDM strategy to all relevant stakeholders, focus on reducing the non-revenue water, implementation of various project related to pressure management, encourage culture of using water efficiently through educational and community awareness campaigns, capacitation of BCMM including seeking financial support, continuous review of the strategy and exploring other water supply sources to relax the already constrained existing water sources. The limitations of the study compared to the broader scope of water conservation and water demand management aspects are highlighted and acknowledged. Thus, in the conclusion of this study, further future studies are suggested to explore other related aspects of water conservation and water demand management in BCMM. , Thesis (MBA) -- Faculty of Commerce, Rhodes Business School, 2021
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- Date Issued: 2021-04
Effect of different fat levels and Moringa oleifera leaf meal (MOLM) inclusion on proximate composition, fatty acid profile, lipid oxidation, and sensory attributes of chicken droëwors
- Authors: Tembela, Nelisiwe
- Date: 2020-11
- Subjects: Moringa oleifera , Meat--Quality , Broilers (Chickens)
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20893 , vital:46709
- Description: The objective of the study was to determine the effect of different fat levels and Moringa oleifera leaf meal (MLM) inclusion on sensory attributes (aroma, meat flavour, spicy flavour, texture, colour, and saltiness), lipid oxidation, proximate composition, and fatty acid (FA) profile of chicken droëwors. Firstly, sensory attributes of chicken droëwors with different levels of fat and that of Moringa oleifera leaf meal were determined. In the second experiment, the effect of different fat and MLM inclusion levels on lipid oxidation during drying and storage, proximate composition, and fatty acid profile were also determined. A forty randomly selected consumers of different gender and age were used as the sensory panel. 75 percent of lean chicken meat and 25 percent of chicken fat was used during droëwors preparation. Thereafter, 9 treatments of chicken droëwors were produced, with MLM included either at 0 percent, 0.25 percent, 0.5 percent, and fat included at 10 percent and 15 percent. For fatty acid profile, the total lipid from dry sausage of all treatments was quantitatively extracted using chloroform and methanol in a ratio of 2:1. Lipid oxidation was measured by analyzing thiobarbituric acid reactive substances (TBARS) at intervals during drying (0, 0.25, 0.5, 72h) and after 7 days of storage under ambient conditions. The results showed that consumers like the chicken droëwors when 0.5 percent MLM added to the product. The inclusion of MLM in chicken droëwors had a positive effect on consumer sensory. The results of the study demonstrated that chicken droëwors contained a significantly higher percentage (P<0.05) of C18:1c9 (Oleic) (30.95 to 32.65 percent) acid than other fatty acids. Polyunsaturated fatty acids (PUFAs) were all non-significant (P˃0.05) except for Docosahexanoic, which was observed to be significant (P˂ 0.05) in all treatments except T1. There was no significance (P> 0.05) in mono-unsaturated fatty acids (MUFAs), except for Elaidic, vaccenic, linoleic, y-linoleic, erucic, and arachidonic. Lipid oxidation occurred more rapidly (P<0.05) when MLM was not added. During processing and storage, TBARS were higher (P< 0.05) in chicken droewors. TBARS during storage were lower (P>0.05) with MLM added. Results showed a significant difference (P<0.05) in proximate composition of chicken droëwors, containing on average 16.93±1.29 to 10.79± 1.83/ 100 g moisture, 45.80± 1.65 to 67.56± 2.33/ 100 g protein, 14.37± 2.15 to 26.13± 2.15/100 g ash. The current study resultsgave a summary of the composition of chicken droëwors and showed higher susceptibility to lipid oxidation in chicken droewors. Therefore, Moringa oleifera leaf powder showed antioxidant activity in chicken droëwors, reserved lipid oxidation in the product. In conclusion, MLM could be used as a functional antioxidant preservative in chicken droëwors. , Thesis (MSc) (Animal Science) -- University of Fort Hare, 2021
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- Date Issued: 2020-11