Thesis (M.S.)--Western Washington University, 2009. / Includes bibliographical references (leaves 46-52). Also issued online.

Thesis (MSc)--University of Stellenbosch, 2008. / Bibliography. Also available via the Internet.

Thesis (M. Sc.)--Memorial University of Newfoundland, 1997. / Restricted until November 1998. Bibliography: leaves 172-179.

Thesis (Ph. D.)--University of Western Ontario, 2008. / Includes Vita. Title from PDF title page (viewed on May 25, 2010) Available through UMI ProQuest Digital Dissertations. Includes bibliographical references (leaves 86-89). Also issued in print.

Thesis (Ph.D.)--Hong Kong University of Science and Technology, 2004. / Includes bibliographical references (leaves 159-187). Also available in electronic version.

Thesis (M. Sc. (Zoology and Entomology))--Rhodes University, 2006.

Thesis (M. Sc.)--University of Hong Kong, 2006.

M.Sc. / Rivers always borrow a great part of their character from the terrestrial ecosystems – the catchments – through which they flow. A multitude of natural factors determines the health of a river ecosystem, however, together with these natural factors, the combined influences of urban development, pollution, bank erosion, deforestation (and ironically many forms of afforestation), and poor agricultural practices have so degraded our rivers that they are under severe threat. One particular group of organisms within river ecosystems that are affected by human-induced changes, are birds. Birds are rather adaptable organisms; many species are able to inhabit human environments very successfully. However, some bird species are highly specialized and adapted to specific environments, like riparian and riverine zones, and their absence or presence is a useful aid in indicating the ecological integrity of an area. In the past, management of aquatic ecosystems was based primarily on chemical water quality monitoring. However, it is impractical to monitor each component of river make-up in detail, therefore monitoring of biological components (biomonitoring) was also incorporated; using selected ecological indices that are representative of the larger ecosystem, and that are practical to measure. Common examples of biotic assemblages that have been incorporated into biomonitoring and used in biotic indices are aquatic macroinvertebrates, fish, plants and algae. Each assemblage is useful in its own particular way in providing us with an integrated view of the integrity of the ecological system as a whole. However, little research has been done on the potential of using birds in a suitable index to monitor changes in the environment. Because birds are so easily observed, their species so easily identified, and their distribution so widespread, it seems viable that birds could also be incorporated into an index of biotic integrity, and used for short- or long-term monitoring of river ecosystems. The river that was selected for the purposes of this study was the Sabie River, in Mpumalanga, South Africa. The Sabie River catchment falls within the Incomati River basin, which is an international drainage basin occupied by South Africa, Swaziland and Mozambique. Land use in the catchment is characterized by forestry, rural community activities (subsistence and small scale farming of livestock and fruit), and conservation activities, in particular the Kruger National Park. In order to gain better understanding of the functioning and composition of the instream and riparian zones of the Sabie River, certain indices were applied, namely the SASS 5 aquatic invertebrate index, together with the Index of Habitat Integrity (IHI). / Dr. G.M. Pieterse

M.Sc. / The Hartbeespoort Dam is located in the North-West Province, downstream of the confluence of the Crocodile River and the Magalies River. The dam was originally built for agricultural purposes and the surrounding area has many canals for irrigation. The use of pesticides for agricultural practices within the area which are transported by the canals, are of great concern. It is well known that residues of persistent pesticides (especially those of organochlorine) and insecticides are found in terrestrial and aquatic environments as well as in the organisms occupying these niches. Such xenobiotics are highly lipid soluble and lengthy exposure to them results in their high accumulation in non-target organisms, all contributing to adverse effects on the ecosystem. The upper Olifants River catchment comprises the drainage areas of the Olifants River, Klein Olifants River and Wilge River, with tributaries down to the Loskop Dam. Over the past few years, the Olifants River has been systematically impaired because of an increase in agricultural and mining activities, industrial development and urbanisation. Recent fish kills in the Loskop Dam has lead to many controversies about the water quality in the Olifants River. The aim of this study was to determine through the use of biomarker responses if it would be possible to identify whether sub-lethal pesticide exposure occurs in fish populations in the Crocodile- and Olifants River systems. Both active biomonitoring (ABM) and passive biomonitoring (PBM) were carried out at selected sites in the Crocodile River system. The ABM technique involved the transplantation of bioindicator organisms, in this case fish, and exposing them for a period of four weeks. The ABM and PBM exposures were carried out during different pesticide spraying regimes, which also coincided with high (summer) and low (winter) flow conditions. Following the exposure period, the organisms were removed and assessed for biological responses (biomarkers). General biomarker responses used in pesticide exposure i.e. acetylcholinesterase (AChE), malondialdehyde (MDA), catalase activity (CAT), protein carbonyls (PC), cellular energy allocation (CEA) and condition factor (CF) were determined. The same suite of biomarkers used in the Crocodile River system was used to determine responses in resident fish species in the Olifants River system.

M. Tech. / Diarrhoeal disease is an important public health problem worldwide as it is responsible for approximately 4 billion cases of diarrhoea per annum, of which 1.8 billion cases result in death. In most cases the causative agents are bacterial entero-pathogens such as Escherichia coli (E. coli), Salmonella, Shigella and Vibrio species. They enter the human body after consumption of contaminated water and food via the faecal-oral route of transmission. These pathogens are therefore identified from faecal matter with microbiological methods such as culture based techniques. There are however certain factors which negatively impact on the diagnosis. Recent literature has shown that bacterial pathogens may not be detected when they enter into a viable but non-culturable state (VBNC) making it difficult to detect the bacterial pathogens with culture based methods. The aim of the study was to detect entero-pathogenic bacteria from stool specimens using optimised protocols and a novel collection technique called the Bio-wipe kit. In the past sterile containers were used to collect and transport faecal matter to the WHRU laboratory for analysis. The disadvantage of this collection technique was that individuals were hesitant to provide faecal matter in a transparent container due to their social and moral status. The Bio-wipe kit eliminated some of the problems encountered with the previous collection technique as it is used in the same way as toilet tissue. Factors such as storage time and temperature was investigated for the recovery of faecal matter from the Bio-wipes since it was used in rural villages where the stool samples can not be refrigerated and transported to the lab immediately after the diarrhoeal episode. It was shown that the bacterial DNA can be recovered from the Bio-wipes within 5-10 days after usage when stored at 30°C and within 14 days after usage when stored at ambient temperature. Comparison of two in-house DNA extraction methods with the commercially available QIAamp® DNA stool mini kit indicated that the Guanidium thiocyanate without alpha casein method (GuSCN non ά-casein) could efficiently recover bacterial DNA from faecal matter free from the presence of inhibitors. This methodology could successfully recover amplifiable bacterial DNA in 92% (181/197) of the clinical Bio-wipes collected from individuals in the rural areas of the Vhembe region of the Limpopo province of South Africa. Various multiplex PCR’s (m-PCR) were optimised for this study for the detection and classification of diarrhoeagenic E. coli types, Salmonella, Shigella and Vibrio species. These m-PCR’s were proven to be very sensitive at detecting diarrhoegenic E.coli, Salmonella, Shigella and Vibrio species bacteria from the Bio-wipes. The extracted bacterial DNA from Bio-wipes recovered from clinical samples was amplified with the single genus specific multiplex PCR and 92% (181/197) of the samples tested positive for the E. coli mdh housekeeping gene, 3% (7/197) tested positive for the sodB housekeeping gene for V. cholerae spp, 5% (10/197) tested positive for the IpaH and Ial virulence genes for Shigella spp. and entero-invasive E. coli (EIEC) whereas none of the samples tested positive for the Salmonella virulence gene (IpaB). These results were confirmed with species specific multiplex PCR for each pathogen. It was concluded from this study that the Bio-wipe kit could be used for the collection of diarrhoeal and non-diarrhoeal faecal matter. The bacterial DNA could effectively be isolated from the recovered faecal matter using the GuSCN non α-casein DNA extraction method. The genus specific m-PCR was able to amplify low levels of bacterial DNA isolated from the Bio-wipes and thus the causative agents for diarrhoeal disease can successfully be diagnosed with the genus specific m-PCR. The Bio-wipe kit can be implemented for routine analysis and during diarrhoeal outbreaks as it is a cost effective, easy to use collection kit. The bacterial pathogens can easily and rapidly be diagnosed using the optimised molecular techniques instead of classical culture-based techniques.