Upwelling over submarine canyons: an in-situ and modelling approach
- Authors: Rautenbach, Gustav
- Date: 2021-04
- Subjects: Gqeberha (South Africa) , Eastern Cape (South Africa) , Oceanography -- Research -- South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/52078 , vital:43442
- Description: The iSimangaliso Wetland Park, located along the coastline of northern KwaZulu-Natal (KZN), hosts South Africa's only tropical coral reef system and is clustered with submarine canyons. These ecosystems support a flourishing diving and pelagic sportfishing industry in the area that contributes tens of millions of rand to the South African Gross Domestic Profit (GDP) annually as well as to provide income and job security for the majority of the local residents. Understanding the oceanographic dynamics, particularly upwelling events, will improve current knowledge of how the ecosystem works and may enhance conservation techniques. The upwelling events within the iSimangaliso Wetland Park results in the influx of cold and nutrient rich waters that supports biological productivity in the area. The complex oceanography, dominated by the Northern Agulhas Current and mesoscale eddies that stem from the Mozambique Channel and South East Madagascar Current (SEMC) is understudied and lacks understanding. This thesis aims to build upon the current knowledge of the upwelling events over the submarine canyons and the concurrent influence on the Mixed Layer Depth (MLD). At the submarine canyons, six anomalous cooling events were identified from surface and subsurface measurements extracted from the Operational Sea Surface Temperature and Ice Analysis (OSTIA) Sea Surface Temperature (SST) and from data collected using Underwater Temperature Recorders (UTRs) over a 12-month period. Depth-integrated lagged correlations showed a 2-to-7-hour lag period from the deep to shallow stations, suggesting that the anomalous cooling events are in fact upwelling events. Wind measurements from the Mbazwana Weather Station and snapshots of sea-level anomalies illustrated that the weaker and shorter upwelling events are driven either by alongshore wind stress or a cyclonic eddy event solely; whereas the stronger event was driven by the combination of both forcing mechanisms. An idealized canyon ocean model is used to interrogate the two forcing mechanisms more fully and showed that the most intense upwelling events are driven by the combined effect of upwelling-favourable alongshore wind stress and a cyclonic eddy which results in strong upward vertical velocity anomalies and the greatest shallowing (6.88 m) of the MLD. With the contribution of the in-situ measurements as a baseline study it is apparent that the idealised model does provide an improved understanding of the upwelling events and forcing mechanism over the submarine canyons within the iSimangaliso Wetland Park. , Thesis (MSc) -- Faculty of Science, Ocean Sciences, 2021
- Full Text: false
- Date Issued: 2021-04
Using narratives to understand consumer behaviour, nutrition knowledge perceptions and experiences amongst women at Thembeni Location
- Authors: Ben, Sive https://orcid.org/0000-0003-4186-924X
- Date: 2021-04
- Subjects: Women -- Nutrition
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20164 , vital:45381
- Description: Orientation: Nutrition knowledge is an important aspect which shapes the lived experiences of women when they are making a purchase. South Africa, being a developing country, is faced with many challenges that have in turn subjected rural women to various challenges in approaching nutrition. These challenges include but are not limited to low economic status, low levels of education, and lack of developmental programmes that are structured to cater for rural women. Purpose: The purpose of this study was to understand the experiences and the perceptions of rural women concerning nutrition knowledge. Motivation for the study: This study was conducted with a motivation to understand how a sample of women in a rural area approach issues of nutrition. In understanding this, women can be empowered in asserting the approach to consumer behaviour. Research design: A phenomenological philosophy was adopted using a qualitative tradition in pursuit of the research objective. A judgemental sampling technique was utilised to sample 20 women and semi-structured interviews were undertaken and the gathered data on the experiences and perceptions of women was analysed by way of narrative analysis. , Thesis (MCom) -- Faculty of Management and Commerce, 2021
- Full Text:
- Date Issued: 2021-04
Variation in forage quality in subtropical thicket
- Authors: Nyembe, Khulisile Jacqueline
- Date: 2021-04
- Subjects: Gqeberha (South Africa) , Eastern Cape (South Africa) , Biodiversity -- South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/52088 , vital:43440
- Description: Several studies have assumed that the plant communities of the Subtropical Thicket biome are nutritious throughout the year. This is based on the observation that they are evergreen, palatable and grow on fertile soils; however this assumption has not been tested. Therefore the aim of this study was to assess forage quality variation in the Subtropical Thicket. This was done at three levels; first we measured the plant quality of dominant plant species in the diets of Thicket herbivores. Secondly, we measured the realised diet quality of Thicket herbivores through the analysis of faecal samples. Lastly we assessed the body condition of Thicket herbivores. The study was conducted at the Colchester (plant quality and diet quality) and Addo Main Camp (body condition assessment) sections of Addo Elephant National Park. To measure the food quality of Thicket plants we analysed 10 plants that are dominant in the diets of Thicket herbivores. To measure diet quality we collected faecal samples from ten herbivores with body mass ranging from 25 kg to 6000 kg. Plant quality results showed that only 30% of the sampled plants met the high energy goat diet protein requirements and that all the sampled plants did not meet the high energy goat diet fibre requirements. This indicates that Thicket plants are not as highly nutritious as they were thought to be. The principle components analysis together with overlapping confidence intervals showed that there was no significant difference between the summer plant samples and the winter plant samples. The faecal quality results showed that there was significant seasonal difference and that faecal diet quality was a function of body size. The body condition results showed that all the sampled herbivores lost condition in the cold dry months. The evidence from faecal diet quality and body condition assessment is sufficient for us to reject the assumption that Thicket forage is consistently nutritious throughout the year. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2021
- Full Text: false
- Date Issued: 2021-04
Workplace forums and the enhancement of collective bargaining
- Authors: Silo, Zama
- Date: 2021-04
- Subjects: Gqeberha (South Africa) , Eastern Cape (South Africa) , Collective bargaining--Law and legislation
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/51189 , vital:43229
- Description: Historically, workers in South Africa, black and Africans in particular, fought against an oppressive regime and, in the absence of political rights, strikes were mostly violent. Labour legislation was based on racial categorisation and discrimination. There was parallel labour legislation for blacks, and a different one for whites. The legislation for blacks was called the Black Labour Relations Act 48 of 19531 , for whites it was called the Industrial Conciliation Act, it was later renamed the Labour Relations Act 28 of 19562 . Trade unions were racially divided, and black workers mostly were denied the right of joining trade unions. The unions that admitted blacks as members could not become parties to industrial councils. Before 1979, black workers in South Africa did not have access to the collective bargaining system. After that year, the guidelines proposed by the Wiehahn, Commission brought about certain changes. Attempts were made to establish independent labour organisations for black workers, but both the state and employers applied various strategies to undermine these organisations. One of these strategies was the Native Labour Settlement Disputes Act of 1953, which restricted the representation of black workers on worker committees in the workplace and prohibited them from striking. Black workers therefore never utilised these statutory works committees and by 1971, there were only 18 statutory works committees in the country. The Department of Labour indicated that there was a preference for non-statutory works committees because there were no restrictions in respect of their composition, and they provided a structure by means of which workers could be represented.3 Militant action by black labour in the early 1970s led to the promulgation of the Black Labour Relations Regulation Act of 1973.4 This Act was to extend the existing works committee system. Liaison and coordinating committees were set up to restrain activism among the workers and establish an alternative form for trade unions of labour management communication. Where statutory works committees had only consisted of employees, employers could now half the members of the new liaison committees and their chairman. The growth of these committees led to black workers building up a base for a future independent organisation. , Thesis (LLM) -- Faculty of Law, Mercantile Law, 2021
- Full Text: false
- Date Issued: 2021-04