The escalating population growth and increased forestry, mining, agricultural and industrial development in the catchment areas over past years has had a profound effect upon water quality and quantity, resulting in increased pollution levels and a reduction in flow rates. This is cause for concern not only to water users in the upper catchments but also to the down stream user, the Kruger National Park, which is exceedingly dependent on good quality waters in order to maintain and sustain a large variety of ecosystems. This study was therefore aimed at investigating the physicochemical, nutrient and metal concentrations of four major river systems that transect the park, namely the Luvuvhu, Shingwedzi, Letaba and Sabie Rivers. By virtue of its position along South Africa’s eastern border the Kruger National Park (KNP) receives waters from seven major river systems each of which enter via the western boundary, flow eastwards through the park and on into Mozambique. The majority of the catchment areas of these river systems are situated upstream of the park itself making water quality and quantity management an important yet challenging task. Water quality is a significant and powerful determinant of health of aquatic ecosystems. Full assessment of chemical and physical attributes upon the river systems was supported by biological monitoring thus integrating changes in the system over time. Water and sediment samples were collected seasonally between September 2005 to March 2006 at sites outside and inside the borders of the Kruger National Park. Sites outside were located of sufficient distance from the border so as to be regarded as representative of water quality conditions before entering the Park. At each site physico-chemical variables were measured in the water. Two metal bioaccumulation indicator species (Labeobarbus marequensis and Barbus radiatus) were also sampled during this time period. These samples as well as water and sediment samples were analysed for Al, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn. Physico-chemical analyses of water and sediment allowed for the separation of the rivers into two distinct groups. The Luvuvhu and Sabie Rivers grouped together showing little deviations from normal water quality guidelines. On the other hand the Shingwedzi and Letaba Rivers deviated from normal values sometimes by large degrees. This was particularly true for the Letaba 1a site for all physico-chemical variables barring temperature. Nutrient concentrations correlated with these findings. Nitrates and Sulphates can be identified as possible problem nutrients; however historic data suggest levels to be acceptable for these river systems. Multivariate analysis of sites with regards to physico-chemical and nutrient concentrations produced three major clusters. Determining factors were conductivity, nitrates, organic content and grain size of 53 μm. Fish were utilised as bioindicator organisms in order to quantify the levels of metals available within each river system. These organisms accumulate metals in their tissues and thus provide not only instantaneous data but rather a time integrate of measure of the bioavailability of metals. Although metal concentrations within water, sediment and fish were not consistently high within one system, three distinct trends were observed. Firstly metal levels were generally found to occur in slightly higher concentrations during the high flow periods when waters were turbid; this could be attributed to increased run off from the surrounding lands as well as increased exposure to sediment bound chemicals released back into the systems. Secondly a trend of high concentrations of Cr, Cu, Fe, Pb, Mn, Ni and Zn was found occurring at the Luvuvhu 1, Luvuvhu 2 and Shingwedzi 1 sites during the high flow sampling. Metal levels at these sites were consistently higher than those recorded at other sampling sites. The last trend noted was that the Sabie River on a whole showed lower metal readings with regard to water, sediment as well as fish samples. In order to integrate bioaccumulation data and metal concentrations in the different phases of the water and sediments an equilibrium partitioning (EP) technique was implemented. Toxic effect-derived quality data is the lowest for Al, Cr, Cu, Pb and Zn, whilst product standard-based criteria produce the lowest values for Fe, Mn and Ni. Cadmium values were found to be similar for both criteria. Results indicate that current water quality guidelines are over protective for Al and Fe, whilst those for Ni and Mn are too lenient. The EP method has not been utilised extensively in South Africa and was carried out for the first time upon these river systems, it is thus essential that further research be carried out. Recommendations are made as to the continued monitoring of these diverse systems. It is suggested that each river be looked at in greater detail and that the development of a field biomonitoring programme should be implemented in order to determine the impacts upon the biological components and the aquatic ecosystem as a whole. Future studies should also look at incorporating the use of aquatic macroinvertebrates (SASS 5) as well as other available techniques in order to supply a more detailed assessment. / Prof. V. Wepener Dr. T. Gyedu-Ababio Prof. J.H.J. Van Vuren

Die probleemstelling in hierdie skripsie en die hipotese wat gemaak word sentreer random die beeldhouer Coert Steynberg, die Krugerkop en die jarelange polemiek random hierdie saak. Die hipotese wat bewys moet word is dat Coert Steynberg as gevolg van die jarelange polemiek random die president S.J.P. Kruger Monument in die Kruger-wildtuin 'n proses van introspeksie en geestelike verdieping ondergaan het. Hierdie geestelike verdieping het gelei tot 'n bewuste diep deurdagte vertolking van Paul Kruger as gevolg waarvan Coert Steynberg sy beste beeldhouwerke geskep het. 'n Sinvolle bespreking van Coert Steynberg en sy siening van Paul Kruger kan alleen gedoen word deur sisternatiese analise van aspekte waaraan in die volgende hoofstukke aandag gegee is: Hoofstuk II: 'n Kort lewensbeskrywing van Coert Steynberg, die beeldhouer, word geskets in die konteks van sy tyd. Deur sy historiese gesitueerdheid is Coert Steynberg noodwendig betrokke met die opkoms van 'n nasionale bewussyn en die behoefte aan monumente. Coert Steynberg is dan die logiese keuse om die Afrikaner Volksbeeldhouer by uitstek te word. Hoofstuk III: President S.J.P. Kruger as politieke leier en as die vader van natuurbewaring word deur die Afrikaans- en Engels sprekende bevolkingsgroepe as gevolg van bulle verskillende geskiedbeskouinge verskillend en meestal teenstrydig geinterpreteer. Paul Kruger is vir vele 'n enigma en 'n histories omstrede figuur. Alleen aan die geskiedbeelde van die blanke bevolkingsgroepe word aandag gegee omdat die swart geskiedskrywing in konteks van hierdie skripsie nie relevant is nie. Hoofstuk IV: Coert Steynberg se uitbeelding van pres. Kruger word kronologies behandel; dit wys sy betrokkenheid vanaf sy jeug met Paul Kruger en weerspieël sy heldeverering van Paul Kruger, die gevoel wat die Afrikaner vir sy volkshelde koester. Hoofstuk V: Die voorspel tot die Krugerkop uit die koppie word geskets. Die reuse Krugerkop is die oorsaak van die jarelange polemiek. Die polemiek wys die algehele betrokkenheid van die blanke bevolking wat telkemale beswaar maak teen die reusekop omdat dit die natuur sal skend en esteties onaanvaarbaar is. Egter die grootste faktor wat bydra tot die vurige drif is die omstrede figuur van pres. Kruger. Die reaksie van Coert Steynberg op die polemiek en in die besender op die gevoelens wat oor Kruger geopenbaar word kom tot uiting in sy skeppinge van Paul Kruger. In die laaste deel van hierdie hoofstuk word die verskillende stadia van die Pres. S.J.P. Kruger Monument by die Paul Kruger-hek van die Kruger-wildtuin bespreek. Hoofstuk VI: Nadat bogenoemde aspekte in aanmerking geneem is, sal daar ten slotte tot 'n slotsom gekom word of bogenoemde hipotese bewys is. / Dissertation (Hons.)--University of Pretoria, 1989. / gm2013 / Historical and Heritage Studies / Unrestricted

M.Sc. (Zoology) / The necessity to maintain high water quality standards has become essential not only to man, but also to conserve aquatic life forms. The Olifants, Selati and Letaba Rivers were monitored for water quality variables and metal concentration in water, sediments and muscle, gill, fat, gonads, liver, bile, blood and kidney of the sharp tooth catfish, C. qariepinus. Some of the water quality variables measured were not within the limits of those standards set for the protection of fish and other aquatic life forms. Turbidity seems to be the biggest problem, due to the Phalaborwa barrage. Metal concentrations were found, in descending order, highest in the sediment, fish and water. This pose the problem of metals being reintroduced into the water column when physico-chemical conditions are not favourable. Experimental studies were done with copper on adult C. qariepinus, due to the extensive copper mining activities in the Phalaborwa region. Haematological and enzymatic analyses revealed a interference in metabolic activity after 96 hour copper exposure. Histological studies on the gill morphology, showed an alteration in the structure with a resultant change in respiratory and osmoregulatory function. LC-50 values were determined for adult and juvenile C. qariepinus in order to set new standards for the protection of aquatic lite in a rapidly developing South Africa.

M.Sc. (Environmental Management) / The Kruger National Park (KNP) is a world renowned wildlife reserve and a source of South African ecotourism benefiting the economy. The Olifants River is the largest river running through the KNP and it is known to be one of South Africa’s most polluted rivers. In the winters of 2008 and 2009 Nile crocodile carcasses were found in the Olifants River gorge in the KNP. In a very short period nearly the entire population of Nile crocodile was lost, the cause of which was later identified as pansteatitis. Pansteatitis is caused by lipid peroxidation known to be nutritionally mediated, as it is associated with diets high in polyunsaturated fats, often of fish origin and insufficient antioxidants specifically vitamin E, which is solely synthesized by plants and must therefore be obtained through diet. The hypothesis of this study is therefore that the fish inhabiting the Olifants River are antioxidant deficient, more specifically, vitamin E deficient, causing the wildlife e.g. crocodiles and predatory fish species, that feed on the fish, to become vitamin E deficient as well, and subsequently develop pansteatitis. If the hypothesis is true, the top fish predator in this aquatic system, the tigerfish Hydrocynus vittatus, should therefore also exhibit signs of dietary vitamin E deficiency. The aim of this study was to determine if tigerfish from the Olifants River in the KNP are exhibiting any signs of antioxidant deficiency, specifically vitamin E deficiency. The objectives to accomplish this aim were firstly to analyse the total plasma antioxidant activity using an ELISA assay, and secondly, to perform a histology-based fish health assessment on the target organs of the tigerfish to identify any histological alterations, specifically those known to be associated with vitamin E deficiency. The results were compared to the results from fish of the same species from two reference sites where there have been no signs of vitamin E deficiency, such as pansteatitis-related wildlife deaths. The results of the plasma analysis as well as the histological assessment showed no conclusive signs of vitamin E deficiency in tigerfish from the Olifants River. It is therefore unlikely that the pansteatitis in the affected wildlife is caused by dietary vitamin E deficiency in the aquatic system, but rather by vitamin E depleting mechanisms such as the presence of high amounts of toxicants with pro-oxidant properties, which may be causing an imbalance of pro-oxidants and antioxidants within the body. Hence the rate of vitamin E regeneration cannot keep up with the rate of oxidation. This is occurring only in certain species due to their specific behaviour or eating habits.

>Magister Scientiae - MSc / In the Kruger National Park (KNP) which is the flagship conservation area in South Africa, the impact on groundwater should be kept to a minimum as groundwater plays a vital role in sustaining ecosystem functioning and sustaining baseflow to streams and rivers. For this reason groundwater has been recognized as one of the environmental indicators that need to be monitored. The KNP has adopted a Strategic Adaptive Management (SAM) approach with clear ecosystem management goals. The achievement of these goals is evaluated by using environmental indicators. These indicators are evaluated against thresholds of potential concern (TPC). TPCs are a set of boundaries that together define the spatiotemporal conditions for which the KNP ecosystem is managed. TPCs are essentially upper and lower limits along a continuum of change in selected environmental indicators. Historically, groundwater recharge and surface water interaction with rivers has tended to be overlooked in the KNP. This study proposes a conceptual model of groundwater recharge processes in the KNP, defining when and how groundwater recharge occurs. Two methods were used, the Cumulative Rainfall Departure (CRD) and stable isotopes of ²H and ¹⁸O. An adapted version of the CRD which incorporates a long and short term memory of the system was used to identify possible recharge processes. Further, using the CRD method a reliable reconstruction of the long term groundwater level trends are simulated using monthly rainfall totals with reference to the average rainfall over the entire time series 1936-2009. The stable isotope of ²H and ¹⁸O samples from cumulative rainfall samplers, surfacewater (streams and rivers) and groundwater from boreholes were collected monthly for approximately one year (May 2010 to July 2011). The isotope composition of the groundwater was used to establish whether recharge was immediate or delayed. Additionally, the isotopic composition of surface-water from rivers and streams were compared to that of groundwater to identify surface-water interactions. Groundwater recharge in KNP occurs during the rainy summer months (December to March) and very little to none during the dry winter season (April to September). Recharge takes place during rainfall sequences 100mm or more. The stable isotope records collected from cumulative rainfall, groundwater and surface water (streams and rivers) indicate that groundwater experiences evaporation prior to infiltration. As the KNP experiences high evaporation rates, insignificant rainfall sequences contribute little or zero to recharge. The CRD analysis of groundwater level fluctuations shows that recharge to the aquifers respond to dry and wet cycles that last for 6 to 14 years. The KNP experienced several periods of below-average rainfall and hence no significant recharge took place to the basement aquifers. During a normal rainy season the water levels rise somewhat then starts receding again. It is only during major rainfall events that may occur every 100yrs to 200yrs causing the aquifers to fully recharge. This was perfectly illustrated by the high groundwater levels after the 2000 major rainfall event that recharged the aquifers fully. During below average rainfall years the overall water level trend is drastically declining. The system experiences higher natural losses than gains due to outflow of groundwater to streams and rivers. The KNP is divided down the center by two geological formations, granites along the west and basalts along the east. The combination of the CRD model and the stable isotopic analysis suggest that the dominant recharge processes that occur in the southern region of the KNP are direct recharge via piston flow and indirect recharge via preferred pathways particularly streams and rivers. Along the eastern half of the KNP on the Basalts and Rhyolite direct recharge via piston flow are dominant. Groundwater is not recharged via small streams and rivers (Sweni and Mnondozi Rivers) as it was found that at these particular sites these rivers are detached and do not interact with groundwater. Along the western granitic areas the dominant recharge process are indirect recharge. Recharge takes place via preferred pathways particularly streams and rivers. It was found that ephemeral rivers (Nwatsisonto River) act as sinks for groundwater recharge and influent-effluent conditions are experienced along seasonal rivers (Mbyamiti River). The large perennial Sabie and its tributary the Sand River are consistently fed by groundwater, above all maintaining base flow during the dry season. These rivers act as basin sinks receiving groundwater discharge all year round. Using the stable isotope composition of rainfall, surface-water and groundwater to act as a natural tracer, in combination with the CRD method proved invaluable to confirm the plausible recharge processes. The study provided a conceptual understanding of the groundwater system in the KNP forming the foundation to developing acceptable limits (TPCs) of the groundwater levels in the KNP. The model will serve as a guide for the recharge processes and for deciding on the location and time frames for data collection to ultimately set TPCs for groundwater in the KNP to sustainably manage the resource.

Please read the abstract in the section 00front of this document / Dissertation (MSc (Wildlife Management))--University of Pretoria, 2007. / Animal and Wildlife Sciences / unrestricted

The objectives of this study were(1) to analyse a data-set on cheetah home range size, habitat utilisation, prey selection and hunting behaviour in the Kruger National Park (KNP), and (2) conduct a comparative study on the above aspects of cheetah ecology across a variety of African savanna ecosystems. Cheetah home range sizes in the KNP for territorial male cheetahs were 173 km2, 438 km2 for a nomadic male cheetah coalition, and 193 km2 and 179 km2 for two female cheetahs. Cheetahs preferred open savanna habitat, although females used areas with thicker bush such as drainage lines) more than males, probably because this is the preferred habitat of their main prey. Analysis showed that while females were closely associated with drainage lines, males were closely associated with roads. A male cheetah coalition preferred scent marking along roads rather than in the bush. Impala occurred most frequently in the cheetahs’ diet, although males took larger prey than females. Cheetahs hunted and killed more frequently in open savanna, even though impala densities were higher in adjacent habitats. Mean chase distance for successful hunts was 18l9 m and unsuccessful hunts was 96 m. Cheetah hunting success was 20.7%, kleptoparasitism was 11.8%, mean kill retention time was 165 min, kill rated averaged 1 kill per 4.61 days, and consumption rate of a three-male cheetah coalition was 1,4 kg meat/cheetah/day. Across African savanna ecosystems, female cheetah home range size was determined by the dispersion patterns and biomass of medium-sized prey. Female home range size was larger in areas with migratory (833 km2) than sedentary prey (105 km2) and increase as prey biomass decreased in areas with sedentary prey only. Conversely, male cheetah territory size was smaller in areas with migratory (37 km2) than sedentary prey (108 km2). Although it was predicted that male cheetah territory size would be determined by female cheetah density, no relationship was found here. Across a range of African savannas, cheetahs showed distinct preferences for open habitats that provided some woody cover. Adults (40%) and juveniles (20%) of medium-sized prey made up the largest proportion in the cheetahs’ diet. There were, however, significant variations in the size and age groups of prey taken by cheetahs in different areas. Areas with the least amount of cover appeared to have the longest mean chase distance, and the greatest percentage hunting success and incidents of kleptoparasitism (%). A population viability analysis, using VORTEX, found that cheetah population viability was greater in a woodland savanna than a grassland savanna, particularly at small population sizes. While the grassland savanna population was most affected by changes in juvenile mortality the woodland savanna population with exceptionally high cub mortality may be a sink for cheetahs while the woodland population with lower cub mortality and predicted high dispersal rates may be a source. Maximum annual litter size and female mortality rates had large impacts on population persistence. / Dissertation (MSc (Zoology))--University of Pretoria, 2006. / Zoology and Entomology / unrestricted

Please read the abstract (Uittreksel) in the section, 00front of this document. See also 10summary / Dissertation (MSc (Zoology))--University of Pretoria, 2007. / Zoology and Entomology / MSc / unrestricted

Set in the historic centre of Pretoria CBD, this study draws extensively on its context to formulate an appropriate response to bringing about urban regeneration in this section of the city. The study was initiated with the selection of a small site set in the percieved northern portion of the inner city. By challenging both the alleged threshold between the 'north' and the 'inner city' and the city council's proposal for the surrounding sites, the proposed building attempts to create meaningful space while enriching the visitor's experience of his immediate surroundings. / Dissertation (MArch(Prof))--University of Pretoria, 2008. / Architecture / unrestricted

Worldwide there is a growing concern of the emergence and evolution of antimicrobial resistance among bacterial pathogens, which poses a threat to human and animal health. The extensive use and misuse of antimicrobials in human and veterinary clinical therapy and agricultural practices have been a major selective force for the emergence, selection, and dissemination of antimicrobial resistant bacteria and resistant genes. Commensal bacteria constitute a reservoir of resistant genes and their level of resistance is considered to be a good indicator for resistance problems to be expected in pathogens. The monitoring of the prevalence of resistance in indicator bacteria such as faecal Escherichia coli and enterococci in different human and animal populations allows the comparison of the prevalence of resistance and to detect transfer between animals and humans and vice versa. Antimicrobial resistance has however, been found in the bacteria of wildlife not exposed to antimicrobials and living in remote areas of this earth. This has implications for resistance control strategies. Previous studies on antimicrobial resistance in wildlife have yielded contrasting results, such as an almost complete absence of resistance in enterobacteria isolated from moose, deer and vole in Finland compared to a high prevalence of resistance in faecal bacteria from wild rodents living in northwest England, which are possibly due to differences in the ecological systems and the proximity to anthropogenic activities. This study further investigates the phenomenon of antimicrobial resistance in wildlife. A previous study conducted in the conservancy area of Kruger National Park (KNP) within South Africa showed that surface water could be a possible source of antimicrobial resistance in unexposed animal populations and that impala (Aepyceros melampus) were good sentinel animals for the documentation of antimicrobial resistance through rivers. This current study followed on this hypothesis and investigated the prevalence of resistance in commensal bacteria isolated from impala and their water sources in KNP. The following four perennial river systems were selected: the Olifants, the Letaba, the Crocodile, the Sabie-Sand Rivers. Samples of river water (n=11) and faeces (n=165) were collected at 11 different sites along these rivers. Samples were directly plated and resistant colonies were selected by means of discs containing antimicrobials (direct plating method). Resistant colonies that grew in the presence of antimicrobials were cultured and identified. Isolates of E. coli (n=12), Enterobacter cloacae (n=49), Pantoea species (n=9), Enterococcus faecalis (n=59), Enterococcus faecium (n=4) and Enterococcus durans (n=64) were tested for susceptibility to a selection of commonly used veterinary antimicrobial drugs. Susceptibility to 18 antimicrobial drugs was determined by means of minimum inhibitory concentrations (MIC) using a commercial MIC test (Sensititre® Bovine/Porcine plate format BOP06F). Our results allow us to give further support to our working hypothesis that antimicrobial resistance, as evidenced in the impala faeces, may have been due to the impala drinking from the polluted rivers, knowing full well that impala are not routinely subjected to any form of antimicrobial treatment. Although the isolates obtained from the water sources were not as many as those obtained from the faecal samples, a degree of resistance was also observed across all the four river systems that we isolated bacteria from, and this was also evident in the faecal samples as well. Our results also further add to the importance of wildlife as sentinels in environmental antimicrobial resistance studies. / Dissertation (MSc)--University of Pretoria, 2013. / gm2014 / Veterinary Tropical Diseases / Unrestricted