A dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of requirements for the degree of Master of Science. February 2015. / This dissertation is an assessment of the compliance with and performance of the Instream Flow Requirement (IFR) system and the Building Block Methodology for the Sabie-Sand River. Firstly, a comprehensive exploration of aspects of the ecological system in the Sabie-Sand Catchment is set out and explored in an attempt to garner an understanding of the pertinent ecological components of the river, in the form of a literature review. This is done with a view to gaining insight into where potential ecological failure may occur should flows in the Sabie-Sand be inadequate for ecological maintenance. A range of abiotic and biotic factors are investigated, and the manner in which they might change in response to changing flow conditions is set out.

The first of a series of mass mortalities of Nile crocodiles in the Olifants and Letaba rivers in the Kruger National Park (KNP) was reported in the winter of 2008. The present study investigated the levels and possible effects on eggshell thickness of inorganic elements and organic pollutants in Nile crocodile eggs from these rivers, and comparing them with eggs from a reference crocodile farm and a reference dam inside the KNP. The egg contents were analyzed for chlorinated organic compounds and brominated flame retardants. Eggshells and egg contents were analyzed for inorganic elements. The elemental concentrations in the eggshells and contents were low when compared with previous studies. The highest concentrations were found in the eggs from the reference crocodile farm. The eggs from the reference dam and the crocodile farm had thicker shells, and the eggs from the Olifants and Letaba rivers had thinner shells. Not all eggs in a female develop at the same rate, while eggshell formation presumably occurs at the same time for all eggs. As a result, the elemental profile of egg contents may differ between eggs of the same clutch, but less so for the shells. Weak or no associations were found between the elemental concentrations of the content and eggshells and eggshell thinning. A possible organic pollutant–induced eggshell thinning effect was found. The compounds found were not at levels that could have caused the mortalities, but may affect the sex ratios through endocrine disruption. Further studies are therefore required. / Thesis (M.Sc (Environmental Science))--North-West University, Potchefstroom Campus, 2011.

The first of a series of mass mortalities of Nile crocodiles in the Olifants and Letaba rivers in the Kruger National Park (KNP) was reported in the winter of 2008. The present study investigated the levels and possible effects on eggshell thickness of inorganic elements and organic pollutants in Nile crocodile eggs from these rivers, and comparing them with eggs from a reference crocodile farm and a reference dam inside the KNP. The egg contents were analyzed for chlorinated organic compounds and brominated flame retardants. Eggshells and egg contents were analyzed for inorganic elements. The elemental concentrations in the eggshells and contents were low when compared with previous studies. The highest concentrations were found in the eggs from the reference crocodile farm. The eggs from the reference dam and the crocodile farm had thicker shells, and the eggs from the Olifants and Letaba rivers had thinner shells. Not all eggs in a female develop at the same rate, while eggshell formation presumably occurs at the same time for all eggs. As a result, the elemental profile of egg contents may differ between eggs of the same clutch, but less so for the shells. Weak or no associations were found between the elemental concentrations of the content and eggshells and eggshell thinning. A possible organic pollutant–induced eggshell thinning effect was found. The compounds found were not at levels that could have caused the mortalities, but may affect the sex ratios through endocrine disruption. Further studies are therefore required. / Thesis (M.Sc (Environmental Science))--North-West University, Potchefstroom Campus, 2011.

Thesis (MPhil)--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: There is a shift by conservation authorities in post-apartheid South Africa away from management strategies based on law enforcement towards strategies aimed at facilitating local community participation in the management of natural resources. South African National Parks has established community forums in order to facilitate better communication with the communities neighbouring it parks, especially around issues of natural resource consumption. However, at its largest Park, the Kruger National Park, a pervasive miscommunication between the Park and the communities appears to exist despite the ongoing activities of its forums. This study attempted to identify what miscommunication, if any, was occurring between three groups of participants in the Conservation Discourse related to the Kruger National Park environment. The participants were (i) South African National Parks (SANParks) conservation managers, (ii) Kruger Park community outreach officials, and, (iii) members of local communities settled on the borders of the Kruger Park. Specifically, the study was interested in how different perceptions of various participants, who also represent different cultural communities, were foregrounded in relation to different communicative goals. It is suggested that an understanding of where the different Discourses diverge can help identify where possible misunderstandings are occurring which may be resulting in communicative problems. My primary research questions were: (1) how do different communities of practice take part in and construct Conservation Discourse related to the Kruger Parks conservation goals, in particular, those related to the use of natural resources; and, (2) how do members of at least three interest groups construct their own identities in relation to conservation matters in the course of various discursive events where SANParks conservation programmes, particularly those related to the use of natural resources, are topicalised. My assumption was that the Parks conservation officers would have a common Conservation Discourse, and that the local communities would have a common discourse but one which deviates entirely from that of the Parks. From 23 September 2008, I conducted three semi-structured interviews with the Parks conservation officers, I was an observer of a Park departmental meeting as well as a Park Forum, and I conducted a focus group with eight members from one of the local communities. This approach enabled me to collect data from a number of different types of communicative events in order to collate a multidimensional picture of the complete Discourse on Conservation. A number of different Conservation Discourses were identified, some of which present significant discrepancies, and which, as in the case of the two of the departments, may be contributing towards what appears to be a serious breakdown in communication. The communities show that while they are supportive of the populist concept of nature conservation, they are completely unaware of the Parks conservation policies. This lack of awareness indicates a failure of the existing communication between the Park and its neighbouring communities despite the Park Forums having been set-up. Finally, the different discourses also appear to be resulting in misunderstandings and feelings of animosity between the different participants. / AFRIKAANSE OPSOMMING: In post-apartheid Suid-Afrika beweeg bewaringsliggame weg van bestuurstrategieë wat op wetstoepassing gebaseer is, na strategieë wat daarop gemik is om die plaaslike gemeenskap se deelname in die bestuur van natuurlike hulpbronne, te fasiliteer. Suid-Afrikaanse Nasionale Parke het gemeenskapsforums in die lewe geroep om beter kommunikasie met die gemeenskappe wat aan sy parke grens, te bewerkstellig, veral rakende kwessies rondom die verbruik van natuurlike hulpbronne. By die grootse Park, te wete die Kruger Nasionale Wildtuin, kom dit egter voor asof miskommunikasie endemies is tussen die Park en sy aangrensende inheemse gemeenskappe, ten spyte van die forums se aktiwiteite. Hierdie studie het nagegaan watter miskommunikasie, indien enige, tussen drie groepe deelnemers aan die Bewaringsdiskoerse rondom die Krugerpark, plaasgevind het. Die deelnemers was (i) Suid- Afrikaanse Nasionale Parke (SANParke)-bewaringsbestuurders, (ii) Krugerpark Gemeenskapsuitreikbeamptes, en (iii) lede van plaaslike gemeenskappe wat op die grense van Krugerpark gevestig is. Die studie het spesifiek gekyk na hoe verskillende persepsies van die onderskeie deelnemers, wat ook verskillende kulturele gemeenskappe verteenwoordig, in die diskoerse op die voorgrond geplaas is afhangende van verskillende kommunikatiewe doelwitte. Daar word voorgestel dat begrip van waar die verskillende diskoerse uiteenloop, kan help om te identifiseer waar moontlike misverstande wat tot kommunikasie-probleme lei, ontstaan. My primêre navorsingsvrae was: (1) hoe neem verskillende gemeenskappe wat rondom gedeelde praktyke gevestig is deel aan Bewaringsdiskoerse wat die Krugerpark se bewaringsoogmerke (en veral daardie oogmerke wat met die gebruik van natuurlik hulpbronne te make het) en hoe konstrueer hulle daardie Diskoerse; en (2) hoe konstrueer lede van ten minste drie belangegroepe hul eie identiteite vis à vis bewaringskwessies in die loop van verskeie diskursiewe gebeurtenisse waar SANParke se bewaringsprogramme, veral daardie wat met die gebruik van natuurlike hulpbronne te doen het, bespreek word. My aanname was dat die Park se bewaringsbeamptes 'n gemeenskaplike Bewaringsdiskoers sou hê, en dat die plaaslike gemeenskappe 'n gemeenskaplike Diskoers sou hê wat heeltemal van die Park s'n verskil. Ek het van 23 September 2008 drie semi-gestruktureerde onderhoude met die Park se bewaringsbeamptes gevoer, ek was 'n nie-deelnemende waarnemer by een van die Park se departementele vergaderings asook by 'n Park Forum, en ek het 'n fokusgroep met agt lede van een van die plaaslike gemeenskappe gelei. Hierdie benadering het my daartoe in staat gestel om data van verskeie tipes kommunikatiewe gebeurtenisse in te samel, om sodoende 'n multi-dimensionele beeld van die volledige Bewaringsdiskoers saam te stel. 'n Aantal verskillende Bewaringsdiskoerse is geïdentifiseer, waarvan party noemenswaardige diskrepansies toon en wat, soos in die geval van die twee departemente, moontlik bydra tot wat lyk na 'n ernstige breuk in kommunikasie. Die gemeenskappe toon dat, hoewel hulle die algemene konsep van natuurbewaring ondersteun, hulle heeltemal onbewus is van die Park se formele bewaringsbeleid. Hierdie gebrek aan 'n bepaalde soort bewussyn dui op mislukking van die bestaande kommunikasiestrukture tussen die Park en aangrensende gemeenskappe, ten spyte van die instelling van die Park Forums. Uiteindelik blyk dit dat die verskillende Diskoerse ook lei tot misverstande en gevoelens van vyandiggesindheid tussen die verskillende deelnemers.

Thesis (MSc (Conservation Ecology and Entomology))--Stellenbosch University, 2009. / ENGLISH ABSTRACT: In 2005, six white rhinoceros (Ceratotherium simum) were reintroduced into Pafuri, in the far northern section of Kruger National Park (KNP), South Africa, as part of a large mammal reintroduction project. All six individuals were fitted with horn radio transmitters. Rhinos have been absent from Pafuri for over a century, and this project aimed to establish a breeding nucleus in the area. The aim of this study was to monitor post-release movement and habitat use of these animals within the 203 km2 study area and assess the short term success of the re-introduction project as well as the suitability of the five landscape types in Pafuri as a habitat for white rhinoceros. Habitat suitability and selection was assessed at two ecological hierarchical scales: 1) landscape system, analysed further down to the spatial scale of range and territory establishment, and 2) feeding station for diet selection. Rhinos were tracked for 12 months and a database of 719 sighting records was compiled. These data were used to determine the utilisation of and preference between the Pafuri landscape types, using preference indices that compare utilisation versus availability. An a-LoCoH nonparametric kernel method was used to calculate home ranges and utilisation distributions of each rhino. Feeding surveys were attempted by backtracking along fresh rhino feeding paths and recording the grass species present and eaten in 0.7 m x 0.7 m quadrats. Faecal samples were collected and analysed using microhistological techniques and dietary composition was assessed for each rhino. Landscape preference analyses showed that the rhinos favoured Colophospermum mopane Shrubveld on calcrete in the dry season, and the Punda Maria Sandveld in the wet season. The territory establishment of the dominant bull was substantially larger (44.8 km²) than those of adult male rhinos in the rest of KNP. Ranging areas of the mature females (17 – 25.4 km²), were consistent with sizes of previous studies. The two sub-adults ranged far more extensively, establishing an 84.1 km² annual range during the study period. The annual diet consisted of mostly perennial grass species, with moderate grazing value species dominating for most of the year. Dietary analyses showed that Schmidtia pappophoroides, Eragrostis superba, Enneapogon cenchroides, Cenchrus ciliaris and Stipagrostis uniplumis were the primary grass species consumed. vii This study demonstrated that the Pafuri rhinos are behaving similarly to rhinos established in other areas, with movements around the landscapes being primarily influenced by rainfall and permanent water sources, and the high quality grazing that is more abundant in the wet season. Their range and territory sizes were inevitably large, for a low density area, but not uncommonly so. The most significant outcome of this study was the preference shown for the Colophospermum mopane Shrubveld on calcrete landscape that is classed as unique within South Africa, and was also ranked as ‘avoided’ by the earlier KNP studies into landscape preferences of rhinos. The grass cover in Pafuri, although sparse and very dry, contained a diversity of low to high grazing value grasses that the rhinos appeared to exploit to the best of their ability. The abundance of moderate grazing value species in their diets, and the low number of low grazing value species suggests that they are maximising the opportunities to graze on nutritious grasses when they are available. Our findings suggest that the Pafuri area is suitable for the establishment of a small breeding nucleus of white rhinos. The abundance of permanent water, in the form of springs, is a great advantage however, the potential for bush encroachment into grasslands in areas of such low rainfall needs to be considered if the population continues to grow at the current rate. The birth of two new calves in 2008 confirms that these rhinos have settled and adapted to their new habitat, and is a very promising sign for the future of this increasing subpopulation. / AFRIKAANSE OPSOMMING: In 2005 is ses wit renosters (Ceratotherium simum) hervestig in Pafuri in die noordelike gedeelte van die Kruger Nasionale Park (KNP), Suid-Afrika, as deel van ‘n groot soogdier hervestigings projek. Al ses individue is gemerk met horing radioseintoestelle. Renosters kom vir al meer as ‘n honderd jaar nie meer in Pafuri voor nie en hierdie projek was daarop gemik om ‘n teel-nukleus in hierdie gesied te vestig. Die doel van hierdie studie was om die verspreiding van die renosters na loslating en habitat-gebruik binne die 203 km2 studie-omgewing te monitor, om die korttermyn sukses van die hervestigings program te evalueer en ook te kyk na die gepastheid van die vyf landskap-tipes in Pafuri as ‘n geskikte habitat vir die wit renosters. Habitatgepastheid en seleksie is geëvalueer volgens twee ekologiese hiërargiese skale: 1) landskapsisteem, wat in meer resolusie tot die ruimtelike skaal van reikwydte en omgewingsvestiging geanaliseer is, en 2) voedings-stasie vir dieet-seleksie. Renosters is vir 12 maande gevolg en ‘n databasis wat 719 waarneming-rekords bevat, is opgestel. Laasgenoemde data is gebruik om die gebruik en voorkeur vir die Pafuri landskap tipes te bepaal met behulp van voorkeur-indikators wat die gebruik met beskikbaarheid vergelyk het. ‘n a-LoCoH nie-parametriese kern metode is gebruik om die reikwydte en gebruiksverspreidings van elke renoster te bereken. Voedingsopnames is gedoen deurdat vars renoster voedings-paadjies terugwaarts gevolg is en die grasspesies teenwoordig en waarop gevoed is, in 0.7 m x 0.7 m kwadrante te bepaal. Mismonsters is versamel en geanaliseer deur gebruik te maak van mikro-histologiese tegnieke en voedingswaarde-samestellings is vasgestel vir elke renoster . Landskapsvoorkeur analises dui daarop dat die renosters in die droë seisoen Colophospermum mopane struikveld wat op kalkreet groei verkies en die Punda Maria Sandveld in die reën seisoen. Die terrein vestiging van die dominanate bul was aansienlik groter (44.8 km²) in vergelyking met die volwasse bul renosters in die res van die KNP. Reikwydte van die volwasse koeie (17 – 25.4 km²) was ooreenstemmend met dié van vorige studies. Die reikwydte van die twee subvolwassenes het baie meer gevarieer, deurdat ‘n 84.1 km² jaarlikse reikwydte gedek was binne die studie periode. Die jaarlikse dieet het meestal bestaan uit meerjarige ix grasspesies, met spesies met matige weidingswaarde wat oorheers vir meeste van die jaar. Voedingswaarde analises dui daarop dat Schmidtia pappophoroides, Eragrostis superba, Enneapogon cenchroides, Cenchrus ciliaris en Stipagrostis uniplumis die primêre gras spesies was waarop gewei word. Die studie het bewys dat die Pafuri renosters soortgelyke gedragspatrone vertoon het as renosters in ander gevestigde gebiede, deurdat bewegings binne die landskap hoofsaaklik beïnvloed word deur reënval en permanente waterbronne, asook die hoë gehalte weidingsbronne beskikbaar gedurende die reën seisoen. Hulle reikwydte- en terrein-groottes was uiteraardelik groot vir ‘n lae-digtheid areas, maar dit is nie buitengewoon nie. Die mees betekenisvolle gevolgtrekking van die studie was die voorkeur vir die Colophospermum mopane struikveld op kalkreet landskappe wat beskou word as uniek aan Suid-Afrika, en wat ook beskou was as ‘vermy’ deur vroër KNP studies tov. landskap voorkeure spesifiek vir renosters. Die grasbedekking in Pafuri, alhoewel yl en baie droog, het tog oor ‘n verskeidenheid grasse beskik wat van lae tot hoë weidings waarde het, en wat die renosters tot die beste van hulle vermoë benut het. Die oorvloedige teenwoordigheid van beide spesies met matige weidingswaarde in hulle dieët en die lae hoeveelheid van spesies met lae weidingswaarde, impliseer dat hulle die geleentheid om op voedingsryke grasse te voed ten volle benut wanneer dit beskikbaar is. Ons resultate dui daarop dat die Pafuri omgewing geskik is vir die vestiging van ‘n klein teel-nukleus van wit renosters. Die oorvloedige teenwoordigheid van permanente waterbronne in die vorm van fonteine is ‘n groot voordeel, maar die kans vir bosindringing in hierdie grasveld-gebiede met lae reënval moet oorweeg word sou die populasie aanhou toeneem teen die huidige tempo. Die geboorte van twee nuwe kalfies in 2008 staaf die moontlikheid dat die renosters gevestig en aangepas het in hulle nuwe habitat, wat ‘n baie belowende teken is vir die toekoms van die groeiende subpopulasie.

PH.D., Faculty of Humanities, University of the Witwatersrand, 2011 / Through a case study of the relationship between the rural Makuleke community and the regional tourism operator Wilderness Safaris, this thesis examines the impact of tourism partnerships on community development in post-­‐ apartheid South Africa. The study considers the tourism component of the ‘Makuleke model’, a concept used frequently in academic and popular literature to refer to the community’s landmark land restitution case involving the Kruger National Park (KNP). Thirty years after experiencing a forced removal by the apartheid regime, the Makuleke community in 1998 was able to regain their lost land (the Pafuri area of Kruger National Park) and benefit from it through conservation and tourism. The Makuleke have partnered with three tourism operators, their main concessionaire being Wilderness Safaris. Their contractual agreement obliges the tourism company to pay lease fees to the Makuleke Communal Property Association (CPA) and to employ Makuleke residents. To further community development, Wilderness Safaris established a joint venture with the Makuleke CPA, and also runs an environmental education programme for children. Evidence for this thesis was collected over a two and a half year period (from May 2007 to December 2009) using three methodological approaches: archival research, participant observation and semi-­‐structured, open-­‐ended interviews. In analysing the Makuleke CPA-­‐Wilderness Safaris partnership, findings reveal that ten years after the land claim, the commended ‘Makuleke model’ is neither as conceptually coherent nor as practically successful as is commonly supposed. I argue that although the model denotes success, a closer scrutiny of its foundations, assumptions and context expose inherent forces and practices that hinder its long-­‐ term effective implementation. Influenced by post-­‐development theory, I question perceptions of equality in benefit distribution, critique the juxtaposition of traditional with modern values, and examine contestations over power within the Makuleke community. I demonstrate how these features undermine the potential for the genuine transformation and broad-­‐based social upliftment that tourism-­‐led development purposes to achieve at Makuleke. My research findings confirm post-­‐development theoretical propositions that criticise the contradictions in orthodox development procedures and call for a rethinking of the premises upon which approaches to community upliftment through tourism are generally founded.

A thesis submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Doctor of Philosophy. 24 March in Johannesburg, South Africa, 2014. / The Biosphere Reserve (BR) model of UNESCO’s Man and the Biosphere Programme (MAB) reflects a shift towards more socially accountable conservation, setting a basis for improving the relationships between people and their environment. The BR approach of dual ‘conservation’ and ‘sustainable development’ objectives is a long-term perspective that increases people’s ability to sustainably manage environmental resources into the future. By 2013 the MAB Programme had resulted in 621 sites designated globally since first inception in 1976, with 11 of these new listings since 2012. Yet regardless of this global spatial expansion, there are few examples of BRs successfully conforming to the MAB’s full criteria, as the reality of aligning conservation and development goals in this model has typically favoured one over the other, with examples of development objectives fuelling broad-scale landscape transformation and conservation objectives that have ignored socio-economic opportunities. However there are a number of case studies presented herein that have shown considerable success, and this thesis suggests that the potential opportunities inherent in the model may outweigh implementation challenges. This thesis critically reviews the history and evolution of the Programme internationally, and makes recommendations for the future of the MAB Programme. In the South African context, the BR model has been applied to a regional conservation landscape in the north-eastern part of the country. The Kruger to Canyons Biosphere Reserve (K2C) is a long-established land-use mosaic of socio-economic juxtapositions, where nationally important economic sectors and world-renowned protected areas (e.g. the Kruger National Park) neighbour extensive, mostly rural, human populations engaged in informal livelihood practices. These vast settlement expanses are artefacts of the former political system in South Africa, and have been prioritised by the South African National Government for urgent socio-economic upliftment. Given that understanding the underlying land-use mosaic is essential for successful implementation of the BR model in any landscape, this thesis assessed land-cover change across the BR (1993 – 2006 – 2012), through the creation of land-cover classification maps, analysing spatial changes in cover relative to the MAB theoretical aspirations. It focuses on three consolidated land-cover cover classes: Intact Vegetation, Impacted Vegetation and Settlement, that present a graduated scale of land-use intensities across the BR, acting as surrogates for the ‘environmental’ and ‘human utilisation’ aspects of the BR approach. Results indicate that the spatial distribution of land-cover change in K2C bears little regard for the theoretical BR zonation and the relative limitations on ‘use’ that typifies successful BR implementation. The spatial expansion of Settlement cover replaced adjacent Impacted Vegetation, which in turn encroached in original areas of Intact Vegetation cover, increasingly fragmenting Intact Vegetation across K2C. The expansion of Impacted Vegetation has resulted in the spatial consolidation of communal use areas, which has likely serious implications for the long-term sustainability of current harvesting levels. Anecdotal field observations have indicated community responses to these concerns with the formal fencing of rangelands to secure ownership and control access. Losses of Intact vegetation translate spatially into an area >400km2, with observed land-cover changes occurring beyond the transition zone, encroaching into the (fully-protected) core and (partially–protected) buffer zones. The increased rate of landscape change in the recent observation period (2.3%1993-2006 versus 5.7%2006-2012) poses challenges for landscape management, with future predictions of escalating transformation likely to undermine BR sustainability, as well as options for a regionally connected protected area network. Historical landscape trends predict a further 5.1% loss of intact vegetation in the next 6 years (2012 – 2018), yet this may over-estimate the potential for transformation in this landscape. However the possibility of a similar loss over a longer temporal period, i.e. 12 years, is not improbable, with the unprotected matrix landscape of the transition zone having experienced comparable losses since 1993, i.e. 4.17%. K2C has had substantial success with pilot socio-economic projects, and has received formal international recognition for the stakeholder engagement / alignment occurring in the subregion as a result of the BR’s listing here. Given these successes, and the considerable investment in its establishment, it is likely that the BR model here will endure. The results of this thesis contribute to improving implementation success long-term, informing policy and management priorities across the BR. These include contributions to i) a marketing approach for the BR, specifically the importance of a K2C ‘brand’ for enhancing co-operation and strengthening the BR’s regional identity, as well as ii) providing support for land-use planning and decisions related to land-use practices and BR sustainability.

A research report submitted to the Faculty of Science, University of the Witwatersrand, in partial fulfilment of the requirements for the degree of Masters of Science (Environmental Sciences). September 2015. / African elephants (Loxodonta africana) are still being poached and hunted and this could potentially affect their movement. As a keystone species, crucial to maintaining ecosystem function and therefore food webs, it is important to understand the effects hunting may have on their movements. This study was undertaken in the Associated Private Nature Reserves adjacent to the Kruger National Park, where elephants are hunted. I looked at changes in daily displacement distance and distance from hunting and natural mortality events to determine if elephants were affected by hunting events, up to what distance, and to determine whether elephants reacted in the same way to hunting and natural mortality events. I found that elephants are only affected by hunting events when within 1 km of the event, which is consistent with the literature. When considering natural mortality events, they actually diverted movements towards the event location, which is also consistent with literature. These results, however, are based on a very small sample size. In addition, the time of day of the events was not recorded by the wardens of the reserve, and this provided a further limitation for the data analysis and interpretation.

Thesis (M.A. (Sociology)) -- University of Limpopo, 2000 / Please refer to the document

Thesis (M.Sc. (Statistics)) - Rhodes University, 2007. / A thesis submitted in partial fulfilment of the requirements for the degree of Master of Science.