Normal ranges of values for hematological parameters of bluegill gathered seasonally from three lakes were determined. Sexual, seasonal, and inter-lake variations were found. Effects of 2-wk exposure to turbidity on blood parameters included an increase in rbc size and a decrease in small lymphocytes. Effects of 3-hr exposure were increases in rbc count, hemoglobin, and pH and decreases in PG2 and large lymphocytes. The effects of 0.44 and 0.88 ppm chloramines were an increase in blood pH, a decrease in MEV, and severe spastic reactions resulting in loss of equilibrium or death in 90% of the fish. Effects of Flexibacter columnaris included an increase in transformed lymphocytes and a decrease in small lymphocytes.

Ph.D. (Zoology) / The study concept was derived following an information requirement related to the need for the development of a scientifically sound technique to minimize illegal entries at major South African freshwater fishing tournaments. The hypothesis was that fish that are in equilibrium with the environment that they live in should reflect the chemistry of that environment. Therefore it would be possible to chemically link the fish to a specific impoundment and identify whether the fish are indeed from that impoundment or whether they were brought there to be illegally entered at a fishing tournament. The project area consisted of selected lakes within the Vaal, Mgeni, Crocodile (West) and Olifants River catchments in South Africa. The catchments were chosen to contain major sport fishing lakes and to have different sizes, different sources of pollution, different underlying geological compositions and different climates. Soil analyses data from the regional geochemical mapping program of the Council for Geoscience as well as lake sediment and lake water analyses were used to trace chemical elements during weathering, erosion and deposition. This was done to identify unique characteristics that are able to distinguish between water and sediment from individual lakes. It was found that Rb, Sr, Ba, Cu, Ni,Th, Pb, Sc, K, Mg and Ca could be effectively used as single elements or element ratios to distinguish between lakes. Large variation in sediment compositions within individual lakes limited this distinction. Anomalous catchment soil concentrations related to the underlying geology or anthropogenic contamination can however be traced to lake sediments. Rare earth elements are not uniformly distributed in lake sediments or lake waters and sampling localities should be carefully considered when comparing lakes. Leachable soil sulphate distribution patterns from coal mining areas above Lake Witbank and Lake Middelburg extend downstream through Lake Loskop to Lake Arabie (Flag Boshielo). Leachable fluoride, abundant in the Pilanesberg Alkaline Complex extends northwards along rivers draining the complex. The mineralogy of lake sediments was also compared with the major element composition of these sediments as well as with the anion composition of lake water. Genetic rock classification diagrams could be used effectively to show correlations between catchment soil and lake sediment samples both in terms of mineralogy and chemistry. Lake water and fish tissue samples were collected and analysed to investigate the link between element concentrations in lake water and otolith, fin spine, muscle, liver and gill tissues. Using the Sr/Ca elemental ratio, a species-specific correlation was identified between lake water, otolith, spine and gill tissue samples. The best discrimination between fish species was achieved using a Na/Ca versus Mg/Ca elemental ratio diagram of gill tissues. The best discrimination between fish from different lakes was achieved using a Ba/Mg versus Sr/Mg elemental ratio diagram for spine tissue. Sediments from most lakes in the project area showed elevated Hg values during the dry season as well as elevated Hg levels in sediments from the deeper/central part of these lakes. Lake Sterkfontein has a low sediment Hg concentration but contains fish with the highest Hg tissue concentration in the project area. When comparing the Hg distribution in fish muscle and spine tissue from the project area there is a better correlation with species than with location. The Sr isotope ratio of lake water shows a remarkable correlation with the Sr isotope ratio of fish from the same lake. Analytical data showed that fish within a specific lake all have the same Sr isotope ratio in their spines regardless of species, age, sex and condition. The Sr isotope ratio of water generally increases with distance from the source within tertiary catchments and is determined by the prevalent geology of the formations being weathered. In large rivers like the Vaal River where pollution also plays a role the pattern is much more complicated. The Pb isotopic composition of soil samples from Pretoria and the surrounding areas correspond well to the major underlying geological units. Superimposed on this pattern is an anomalous anthropogenic Pb component possibly related to leaded fuel, which extends from the Pretoria city center northwards along the road and railway networks. Water and sediments from Lake Bon Accord and Lake Marais also contain this anthropogenic signature. The hypothesis that fish, which are in equilibrium with the environment that they live in, should reflect the chemistry of that environment, is therefore not rejected since the results of analysing lake water and fish tissues from 23 South African lakes, within 4 major catchments showed definite correlations. Comparing single elements is the least effective method of establishing such correlations. Comparing elemental ratios is a much better method, while comparing isotope ratios is the most effective method.

M.Sc. / A comprehensive histology-based fish health assessment was implemented at the Roodeplaat Dam (RD), Pretoria, South Africa, to determine the health status of two fresh water fish species, Clarias gariepinus (n = 20) and Oreochromis mossambicus (n = 18), after exposure to pollutants. RD is known to be polluted, being impacted from two sewage treatment plants, industry, housing and agriculture all upstream of the reserve. Excessive nutrient loads, such as orthophosphate, resulted in the dam becoming eutrophic. The quality of water in the RD was a cause for concern, as the fish from the dam are being used as a source of food by the local people. The histology-based fish health assessment included fish necropsy, calculation of gross body indices and histological assessment. Water quality (chemical and physical) analysis was also carried. Furthermore, target chemical analysis of fish tissue (skeletal muscle) was performed to determine the levels of contaminants in the consumable parts of the fish. These results were compared with existing international guidelines to determine whether the harvested fish were safe for human consumption. All the information obtained was integrated in a qualitative and quantitative scenario-based health risk assessment.

M.Sc. / Water resources in South Africa are scarce and need to be protected and managed in a sustainable way for future generations. Food supply is a great priority worldwide and the pressure to produce enough food has resulted in the expansion of irrigation and the steadily increasing use of fertilizers and pesticides to achieve higher yields. Rivers are impacted by agriculture through increased suspended sediment loads (which affects primary production, habitat reduction and introduction of absorbed pollutants), elevated nutrient inputs (which may increase the abundances of algae and aquatic plants), salinization and pesticide runoff (which eliminates species intolerant to these conditions and therefore impacts on the normal production of the river system). Aquatic biota plays an integral part in the functioning of aquatic ecosystems. Biological monitoring is used to assess ecosystem health and integrity. Biological communities reflect the overall integrity of the river ecosystem by integrating various stressors and therefore provide a broad measure of their synergistic effects. The research area falls within the Lower Vaal Water Management Area (WMA), which lies in the North-West and Northern Cape Provinces. The lower Vaal River and the Harts River (one of the tributaries of the Vaal) are the river systems under investigation in this study. Farming activities ranges from extensive livestock production and rain fed cultivation to intensive irrigation enterprises at Vaalharts (such as maize, cotton and groundnuts). The Vaalharts is the largest irrigation scheme in South Africa. Salinity is of concern in the lower reaches of the Harts- and Vaal Rivers, due to saline leachate from the Vaalharts irrigation scheme. Agricultural inputs are known to affect aquatic communities and chemicals (e.g. pesticides, herbicides, fertilizers) are extensively used in the Vaalharts irrigation scheme. At present there are no data on the effect of these chemicals on the aquatic biota of the lower Harts- and Vaal Rivers. The aims of this study were to assess the diatom- and macroinvertebrate community structures, ecosystem integrity and macroinvertebrate feeding traits (functional feeding groups – FFGs) in relation to land use.

M.Sc. / Victoria Lake also known as Germiston Lake is an urban impoundment which is situated east of Johannesburg. This Lake is used for a number of recreational activities and can be viewed as an important feature of this area. It is a natural perennial pan and has several inlets (inflows) which drain a part of Germiston's business area and surrounding residential areas. In the past various studies have focused on the water quality as well as other aspects of the ecology of the Lake that may influence recreational activities and the physical-chemical quality of the water. However, information on the physical-chemical quality of the inflow water is poorly investigated and needs further attention. This study gathered further data on the water quality and associated problems within the major inlets to the Lake. Six inlets were monitored monthly for a year. The water samples that have been collected were analyzed for several physical and chemical constituents. In general it seemed as if the waters of the inlets around Victoria Lake were more polluted in comparison to the surface waters of the lake Sites 1, 4 and 5 seemed to be the most polluted inlets and it should be closely monitored in future. Most of the water quality constituents that have been compared with the water quality criteria exceeded the acute effect values given by the South African Water Quality Guidelines. Waste is thus continually dumped into the Victoria Lake via the major inlets resulting in water pollution. The quality of this resource is therefore diminishing rapidly. If Victoria Lake is to be successfully used and managed in order to limit the impact on the environment, all further development and management should take place in terms of sustainable development.

A dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements of the degree of Master of Science in Geology Johannesburg, 1998 / This study determines the potential of prerncting pollution to ground water by sanitary landfills. The tracing capabilities of both stable and radioactive environmental isotopes are also evaluated. Four landfills were selected, the Linbro Park and Waterval sites in Johannesburg, and the Bloemfontein northern and southern landfill sites. The sites all differ in geological environment, size. age and physiographic setting. [Abbreviated Abstract. Open document to view full version] / MT2017

Annually, the global environment receives enormous amounts of persistent organic pollutants (POPs) that include polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs), in addition to polycyclic aromatic hydrocarbons (PAHs). Their ubiquity has made them identifiable contaminants in almost every environmental compartment of the global system. In particular, aquatic systems have been adversely affected by these pollutants. Therefore, effective monitoring, both in ground and surface water, that can reliably assess their environmental impacts is required. Passive samplers have been proposed as suitable options to the traditional grab/spot/bottle sampling approach because they simultaneously sample, isolate and enrich target analytes. Moreover, apart from successfully detecting very low water dissolved analyte concentrations (trace and sub-trace levels), the devices can also provide time weighted average (TWA) concentrations that take into account episodic events. This is usually not practical with other sampling techniques.

São Roque situa-se a 60 km de São Paulo, em uma região composta por serras e morros. A hidrografia do município é composta por bacias tributárias do Rio Tietê. A cidade se desenvolveu às margens dos córregos Aracaí e Carambeí, cujos leitos fluem em margens canalizadas até o deságue no Ribeirão Guaçu. Estes córregos, bem como o Ribeirão do Marmeleiro, encaminham resíduos, detritos e todo o volume de águas pluviais ao Ribeirão Guaçu. Em 2017, foi instalada no município uma estação de tratamento de esgoto visando a melhoria das condições de saneamento na região. Diante disso, este trabalho teve por objetivo avaliar as relações hidroquímicas quanto ao estado de trofia e demais impactos antrópicos na qualidade das águas do Ribeirão Guaçu, São Roque, SP, de modo espacial e temporal, mediante abordagem integrada de multitraçadores ambientais, situando a qualidade da microbacia hidrográfica pré e pós instalação de um sistema de coleta e tratamento de esgoto. Para avaliar a qualidade das águas dos corpos hídricos, foram efetuadas amostragens bimestrais de água superficial, obedecendo às épocas de chuva e de seca. Foram selecionados sete locais estrategicamente escolhidos e georreferenciados. As análises foram realizadas de acordo com os métodos analíticos baseados no Standard Methods for Examination of Water and Wastewater. Foram analisados parâmetros físicos, químicos e microbiológicos, sendo os resultados comparados com os valores permitidos por lei. O IQA foi empregado a fim de se obter um panorama sobre a qualidade hídrica da microbacia em função da sazonalidade e um comparativo entre o período pré e pós-operação da ETE. Os pontos Marmeleiro e Guaçu 4 apresentaram maior influência antrópica. Todos os pontos analisados demonstraram-se comprometidos com contaminantes microbiológicos. Em relação aos físicos e químicos, diversos pontos apresentaram inconformidades. / São Roque is located 60 km from São Paulo, in a region composed of hills. The hydrography of the municipality is composed of tributary basins of the Tietê River. The city developed on the margins of the streams of Aracaí and Carambeí, whose channels channeled flows until the drain in the Guaçu River. These streams, as well as Marmeleiro River, send waste, debris and all the volume of rainwater to the Guaçu River. In 2017, a sewage treatment plant was installed in the municipality aiming to improve the sanitation conditions in the region. The objective of this work was to evaluate the hydrochemical relationships regarding trophic status and other anthropic impacts in the water quality of the Guaçu River, São Roque, SP, in a spatial and temporal way, through an integrated approach of environmental multipliers, placing the quality of the hydrographic microbasin pre and post installation of a sewage collection and treatment system. In order to evaluate the water quality of the water bodies, bimonthly sampling of surface water was carried out, obeying rain and dry seasons. Seven strategically chosen and geo-referenced sites were selected. The analyzes shall be carried out in accordance with analytical methods based on the Standard Methods for Examination of Water and Wastewater. Physical, chemical and microbiological parameters were analyzed, and the results were compared with the values allowed by law. The WQI was used in order to obtain an overview of the water quality of the microbasin according to the seasonality and a comparison between the pre and post-operation period of the STS. The collect points Marmeleiro and Guaçu 4 presented greater anthropic influence. All analyzed points were shown to be compromised with microbiological contaminants. Regarding physicochemicals, several points presented nonconformities.

The diploma thesis is focused on the issue of surface water pollution, which is one of the biggest problems of the contemporary world. The pollution of watercourses and reservoirs worsens the quality of aquatic ecosystems as well as ecosystems in their surroundings. The typical sources of surface water pollution include especially point sources (human settlements, industrial sites) and land resources (agriculture). While the point sources of pollution can be monitored, the situation is far more complicated for the field sources. In agricultural farming, the fertilizer residues, pesticides and other substances come into the groundwater and the surface water. The aim of this work is to find out the quality of surface water in the measuring profiles (river Malše), to find out the hydrological situation during the year and to evaluate the impact of chemical pollution sources influencing the quality of the surface water in the river basin.

Thesis submitted in fulfillment for the requirements for the degree Doctor Technologiae: Environmental Health in the Faculty of Applied Sciences, Cape Peninsula University of Technology, 2012 / Water related issues such as water treatment and distribution have become extremely important all over the world due to population growth, growing urbanization, health and environmental pollutions. Contamination of water bodies especially in Africa with antibiotic resistant bacteria strains is a cause for concern. Escherichia coli O157 H:7, and various strains of non O157 E. coli and Acinetobacter spp. are known for antibiotic resistance. Both bacteria are environmental organisms found coexisting together with high potentials of exchange of resistance genes. Despite the stress conditions confronting these bacteria in water, food and the human body, in the form of disinfectants, antibiotics, salts and the innate immunity, they appear to develop adaptive mechanisms that enable them survive and cause infection. This therefore necessitates the need for investigation of effective virulence factor-targeted control measures. Culture of 62 water samples on Brilliance E. coli/coliform selective medium (BECSM, Oxoid), Eosin Methylene Blue (EMB) agar, or Baumann’s enrichment medium (BEM) and Leeds Acinetobacter Medium (LAM) for the isolation of E. coli and Acinetobacter spp. was carried out. Isolates were investigated for virulence factors, antibiotic resistance and transformation of resistance genes. The effect of oxidative stress exerted by 0.3% Crystal violet, 0.3% Bile salt, 4.0% NaCl, and 8% ethanol on some of the multi-drug resistant strains as well as the effect of stem back extracts of Curtisia dentata on verotoxin production by the verotoxic strains was also investigated. Out of the 69 isolates of E. coli (including O26:H11, O55, O111:NM, 72 O126, O44, O124, O96:H9, O103:H2, O145:NM and O145:H2.) and 41 isolates of Acinetobacter spp. with 26 (53.06%) of the E. coli and 6 (14.63%) of the A. haemolyticus isolates producing verotoxins, and no A. lwoffii isolate produced the toxins. Twenty five - 25(35.23%), 14(20.30%) and 28(40.58%) of the E. coli isolates were positive for VTx1&2, Vtx1 and Vtx2 respectively, 49(71.015%), were positive for extended-spectrum beta-lactamases (ESBLs), 7(77.78%) for serum resistance, 57(82.61%) for cell surface hydrophobicity, 48(69.57%) for gelatinase production and 37(53.62%) for haemolysin production. While transformation occurred among the E. coli and Acinetobacter isolates (transformation frequency: 13.3 x 10-7- 53.4-7), there was poor curing of the plasmid genes, a confirmation of presence of stable antibiotic resistant genes (DNA concentration between 42.7-123.8 μg) and intra-genetic transfer of multidrug resistant genes among isolates. Oxidative stress due to chemicals, salts, alcohol or freeze-thawing (blow temperature stress) exerted various degrees of lethality on E. coli isolates with some bacterial strains losing their potential to express virulence factors with time. There was however, generally insignificant (t test; P≤0.05) lethal effect against all the A. haemolyticus isolates, but crystal violet exerted the highest lethal effect on some individual isolates followed by ethanol, bile salt and NaCl. Isolates from wastewater demonstrated the highest rate of resistance compared to isolates from river water. The cell kill index (CKI) increased as temperature stress (-5; -18; and -28ºC) increased with time. But the rate of loss of expression of virulence factors or viability was slower in isolates from wastewater and abattoir compared to those from river water. Sixty percent of the E. coli isolates showed various levels of resistance to different antibiotics (ampicillin (10 μg), cefuroxime, cephalexin, ceftazidime and tetracycline (30 95 μg in each case)) (multidrug resistance index (MDRI) values 4.20-5.60%). Relative inhibition zone diameters (RIZD) of C. dentata extracts against E. coli serotypes ranged between 8-28% (MIC, 100-2500 μg/ml), while against A. lwoffii and A. haemolyiticus, the RIZD values ranged between 10-28% (MIC, 100-850 μg/ml) and 6-28% (MIC 150-2500 μg/ml) respectively. However, higher MICs (MIC, 70-2500 mg/ml) were recorded for isolates with high MDRI values. Extracts demonstrated inhibitory action against the expression of both Vtx1 and Vtx2 genes in E. coli, A. haemolyticus and A. lwoffii. Saponins, tannins, glycosides, anthraquinones, flavonoids, steroids, phenols quinones, anthocyanins, amines and carboxylic acids were present in C. dentata. Ethanol root bark extracts consistently showed the highest DPPH radical scavenging activity (62.43%), total phenol content (TPH) (57.62 26 mg GAE/g) and reducing power (RP) (41.32%), followed by those of the stem bark and leaf extracts with the respective values of 54.68%, 37.77 mg GAE/g and 21.83%. The extracts also induced the leakage of Na+ and K+ 107 ions from both test bacteria. Detection of virulence factors, antibiotic resistance genes and transformation among these isolates is a very significant outcome that will influence approaches to proactive preventive and control measures and future investigations. Resistant verotoxic A. haemolyticus could further complicate treatment in verotoxic food-borne or nosocomial infections. Induction of cationic leakage by extracts of C. dentata is an indication of one of its mechanism of action on bacterial cells. The plant can therefore be a good source of antibiotic substances for composition as antioxidants or antimicrobials with novel mechanism of action for the treatment of verotoxic bacterial infections.