M.Sc. / The increase in industrialisation, mining and agricultural activity along rivers could have a detrimental effect on aquatic environments unless the dangers of pollutants are not taken notice of. Metal ions and industrial effluent have become a source of pollution in the watercourses of South Africa. Pollutants generally have negative effects on the physiology of aquatic biota in polluted waters. The effects of copper and industrial effluent by the exposure of the clawed toad, Xenopus laevis and Tilapia sparrmanii are presented in this study. An experimental static-renewal system with an exposure time of 96 hours was followed at 25±1°C. After copper and effluent exposure, several physiological changes occurred in the two aquatic organisms. The sublethal effects that occurred include changes in hatching, survival, behaviour, growth impairment and developmental limitations. The results of the present study suggest that lethal endpoints can be used as indicators in detecting and evaluating the effects of aquatic pollution, caused by copper and effluent. Individual variation, however, could hamper the conclusions made but the study of aquatic organisms is of practical importance when conducting experimental studies in a laboratory and does not have the same impact as during field studies. Apart from the exposure to sublethal concentrations of copper and effluent, computational derivations of LC50, NOEC values and 95% confidence limits were made. The obtained concentrations were used as assumptions that pollutants should not exceed for the protection of aquatic life. Statistically different differences were found between the chosen derived variables of control and experimental organisms. The advantages of FETAX solution over borehole water can be attributed to the bioavailability of pollutants, which appears to be much less in those solutions. The predicted NOEC values provide some information regarding the concentrations at which no effects will be observed and the Target Water Quality Ranges (TWGR) for water were used to determine if the diluent was correct.

In a three year study, the applicability of the cortisol response to capture as a biomarker of the health of fish from areas chronically exposed to pollution was assessed. Northern pike (Esox lucius) and yellow perch (Perca flavescens) captured from an area contaminated by bleached kraft pulp mill effluent (BKME) were initially found to be incapable of elevating their blood cortisol concentration to reference levels. Following a reduction of the amount of absorbable organochlorines (AOX) in the BKME, fish downstream of the mill regained their normal cortisol response to capture. The time frame for this recovery was from between 6 to 18 months. Fewer young fish downstream of the effluent provided evidence for the impact of long-term exposure to BKME at the population level. / The impairment of the cortisol response to capture, and its subsequent recovery after effluent reduction provide the foundation for developing cortisol as a biomarker of contaminant exposure. Further work should determine the relationship between cortisol and the effect at higher levels of biological organization (e.g., population and community).

Made available in DSpace on 2016-07-01T13:10:22Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-02-27. Added 1 bitstream(s) on 2016-07-01T13:13:47Z : No. of bitstreams: 1 000865809_20170301.pdf: 260503 bytes, checksum: 3e79e7bc77d518ffd72f73f4301727cb (MD5) Bitstreams deleted on 2017-03-03T11:01:33Z: 000865809_20170301.pdf,. Added 1 bitstream(s) on 2017-03-03T11:02:42Z : No. of bitstreams: 1 000865809.pdf: 1846324 bytes, checksum: 3b33f5972e852e7c38fcb0ac2633d033 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / CAPES: 13836/2013-07 / CNPq: 140359/2011-7 / FAPESP: 12/00561-0

A qualidade da água é um fator importante para o bem-estar do ser humano, e equilíbrio dos ecossistemas naturais. Com o aumento populacional e a consequente industrialização, se intensificou a produção de esgoto doméstico e de efluentes industriais, os quais podem conter metais e acentuar a poluição ambiental. Alguns elementos-traço são considerados essenciais para o desenvolvimento e manutenção dos organismos, porém, se forem ingeridos em concentrações acima das recomendadas, podem ser tóxicos. O objetivo desse estudo foi avaliar o grau de contaminação de duas espécies de peixes (Poecilia reticulata e Hypostomus ancistroides) abundantes do Ribeirão Cafezal (Rolândia - PR) pelos elementos Zn, Cd, Cr e Pb. A coleta dos peixes foi realizada em três pontos ao longo do trecho superior da bacia do Ribeirão Cafezal, utilizando os métodos de pesca elétrica e manual, com esforço amostral de 40 min para cada método. Para a detecção dos elementos traço no material coletado, as amostras foram devidamente preparadas para emprego da técnica de Espectrometria de Emissão Óptica por Plasma Indutivamente Acoplado (ICP-OES). As concentrações apresentadas pelos indivíduos da espécie Poecilia reticulata (pontos 1 e 2) amostrados do ribeirão foram: Zn (107,63; 91,89 mg/kg) , Cd (0,12; 0,42 mg/kg), Cr (2,17; 4,96 mg/kg) e Pb (0,71; 0,44 mg/kg); enquanto que para a espécie Hypostomus ancistroides (pontos 2 e 3) foram: Zn (93,11; 76,97 mg/kg), Cd (2,22; 0,10 mg/kg), Cr (16,05; 2,23 mg/kg) e Pb (2,83; não determinado mg/kg). Todos os valores estão acima dos limites permitidos pela ANVISA (Agência Nacional de Vigilância Sanitária). Não houve diferenças significativas nas concentrações dos metais entre os pontos de amostragem avaliados. Como se trata de um Ribeirão onde as pessoas utilizam a água para recreação e se alimentam dos peixes que colonizam o local, é preciso continuar a atividade de monitoramento, bem como realizar análises sistemáticas com diferentes espécies de peixes, água e sedimento. / Some trace elements are considered essential for the development and maintenance of living organisms. However, if those trace elements are ingested in higher concentrations than recommended can be toxic. The aim of this study was to evaluate the degree of contamination for two abundant species of fish from Ribeirão Cafezal (Poecilia reticulata and Hypostomus ancistroides) with Zn, Cd, Cr and Pb elements. The fish collection was performed at three points along the upper stretch of the basin of Ribeirão Cafezal using electric and manual fishing methods, with sampling effort of 40 minutes for each method. In order to detect the trace elements in the collected material, the samples were properly prepared to the Inductively Coupled Plasma by Atomic Emission Spectroscopy (ICP-OES). The concentrations presented by the species Poecilia reticulata in the two first points of the stream were: Zn (107.63; 91.89 mg / kg), Cd (0.12, 0.42 mg / kg), Cr (2.17; 4.96 mg / kg) and Pb (0.71, 0.44 mg / kg), sampled in 1 and 2 respectively. And individuals of Hypostomus ancistroides species sampled in points 2 and 3 had the following values: Zn (93.11; 76.97 mg / kg), Cd (2.22, 0.10 mg / kg), Cr (16.05; 2.23 mg / kg) and Pb (2.83; nd mg / kg). All values are higher than the limits allowed by ANVISA. There were no significant differences in the metals concentrations among the sampling points assessed. In consideration for Ribeirão Cafezal being a stream where people use water for recreation and feed on the existing fish, we need to continue monitoring it, as well as performing systematic analysis with different species of fish, sediment and water.

Orientador: Reinaldo José da Silva / Banca: Alessandro Francisco Talamini do Amarante / Banca: Lúcia Helena O'Dwer de Oliveira / Banca: Luis Eduardo Roland Tavares / Banca: Ana Cécília Amado Xavier de Oliveira / Resumo: Não disponível / Abstract: Not available / Doutor

M.Sc. / Pollution of the earth is presently one of the most important environmental issues of the world and various attempts, including creation of public awareness have been initiated over the past few years to address this situation. There is especially a global concern about the progressive pollution of valuable freshwater systems which most organisms, including humans, are reliant upon. This includes South Africa's aquatic ecosystems, many of which have been degraded over the past few decades. The Olifants River in Mpumalanga is one of the most threatened river systems in South Africa. It is impacted by various anthropogenic activities, particularly mining in the upper catchment, and urbanisation, industrial and agricultural activities in the upper and lower catchments. Previous investigations have shown that these activities are responsible for the degradation of this river system. The broad objective of this study was to obtain data on water and sediment quality, as well as bioaccumulation of metals in fish via monitoring of the Olifants River. It formed part of a major study concerned with the experimental investigation of lethal and sub-lethal effects of metals on fish physiology, supported by a field investigation into the water quality and metal contamination of the biotic and abiotic components of the Olifants River system. Physico-chemical properties of the water as well as the concentrations of some metals (Al, Fe, Cu, Zn, Ni, Mn, Pb & Cr) in the water and sediment were seasonally investigated. The extent of bioaccumulation of these metals in selected organs/tissues (muscle, gills, liver & skin) of Oreochromis mossambicus and Clarias gariepinus from Loskop Dam (upper catchment) and Mamba Weir, Kruger National Park (lower catchment) was also investigated. High levels of various macro-constituents and metals were detected at many sites in the study area and in many cases they exceeded the guideline limits set for aquatic ecosystems. Localities 2, 3, 6, 8, 10, 12 and 17 were observed to be severely impacted (see Chapter 9- Table 9.1) by elevated concentrations of pollutants influencing variables such as TDS and sulphates. This confirms that these sites are being impacted by mining. This was further confirmed by low pH-values at localities 3, 5, 8, 9, 10 and 12 which indicate on acid mine drainage originating from the many coal mines in the upper catchment of the Olifants River. Nutrient enrichment (elevated levels of phosphates, nitrates and nitrites) occurred at many sites in the catchment but in particular at localities 3, 4, 6, 10, 11, 14, 15 and 17. Point source pollution from sewage treatment works and non-point sources from agricultural runoff and informal settlements are the main contributors to these elevated levels of nutrients. The Selati River, impacted in particular by elevated phosphate levels, is the main contributor to the high nutrient levels detected at locality 17. It is evident from the evaluation of the metal concentrations in the water and sediment (Table 9.2) that most of the sites in the Olifants River catchment are being impacted by metal pollution. Oreochromis mossamhicus and C gariepinus sampled at selected sites in the Olifants River accumulated selected metals in the following order; Fe>Zn>Al>Cr>Ni>Pb>Mn>Cu. Levels were generally high in the liver and gills, while much lower levels were detected in the skin and muscle tissues. Gill tissue is in direct contact with the aqueous environment and therefore gives a good indication of the extent of exposure. Skin tissues usually contained relatively low levels of metals (except for Zn). Although muscle tissues usually accumulated low metal concentrations it is an important tissue to monitor in bioaccumulation studies as it can lead to metal poisoning if contaminated muscle tissues are consumed by humans. Adult specimens were mostly sampled and within this range there was a slight decrease in Cu, Al, Fe, Ni, Mn and Cr concentrations with increasing age. Temporal variation in metal accumulation by fish possibly occurred due to variations in metal concentrations in the water and sediment at a locality. These differences were caused by seasonal variation in climatical conditions (eg. rainfall, temperature), as well as temporal fluctuations of pollutant inputs into the river system. Aquatic organisms at both localities 15 (Loskop Dam) in the upper catchment and 17 (Mamba weir, Kruger National Park) in the lower catchment are at present being chronically exposed to elevated levels of the investigated metals, compared to both the control site and results in literature. The impact of the highly polluted Selati River in the lower catchment was evident in the difference between metal concentrations detected in fish at locality 17, and at locality 19 (Phalaborwa Barrage) upstream of the Olifants-Selati confluence. The present study clearly indicates that the Olifants River is subjected to various sources of pollution which could be detrimental to the health of this aquatic ecosystem. It is recommended (see Chapter 9) that a multi-disciplinary approach including a biomonitoring programme, should be followed to ensure a sustainable freshwater ecosystem.

M.Sc. (Aquatic Health) / The Bojanala Platinum District (BPD) in North West Province (NWP) is a well-established mining and agricultural region of South Africa. These activities result in surface runoffs that are likely to pollute nearby freshwater impoundments, including the Roodekopjes (RD) and Vaalkop Dams (VD). These impoundments support subsistence fishing, where the fish caught, are often the sole source of dietary protein for local communities. The aim of this study was two-fold: firstly, to assess the health status of the fish in these impoundments by (i) conducting a necropsy-based macroscopic evaluation, (ii) calculating appropriate biometric indices, and by (iii) performing a semi-quantitative histology-based fish health assessment (HBFHA) on selected target organs of two freshwater fish species, namely Clarias gariepinus (Sharptooth Catfish) and Cyprinus carpio (Common Carp). Secondly, the edibility (safe for human consumption) of these fish species was to be determined by (i) quantifying the bioaccumulation of selected organic and inorganic toxicants within the muscle of the fish collected and (ii) assessing the resultant potential health risk/s through consumption toward consumers of these fish. In addition, in situ physico-chemical parameters were measured and samples of water and sediment were collected for laboratory analysis at each of the assessed impoundments. Otoliths and scales were also collected for age estimation. Tissue samples for histology were fixed in formalin (liver, kidney & heart) and Bouin’s (gills, gonads & skin) solution and processed for light microscopy analysis using standard histological techniques. Water, sediment and muscle samples were analysed for organic and inorganic toxicants by accredited laboratories using ICP-MS & ICP-OES. Results from the two assessment sites (RD & VD) were assessed against a reference site, the Marico-Bosveld Dam (MBD).

M.Sc. / The water quality monitoring project undertaken on the Blyde River in Pilgrim's Rest and surrounding area, provided information on various parameters. These included the macro variables (pH, temperature, conductivity, dissolved oxygen concentration, oxygen saturation percentage and turbidity), micro variables (ionic and metal concentrations) and fauna (fish and invertebrates). Field and experimental data were integrated to form a realistic and representative picture of the general state of health of the Blyde River. The macro variables (pH, temperature, conductivity, dissolved oxygen concentration, oxygen saturation percentage and turbidity) were all within the guideline limits as provided by the Department of Water Affairs and Forestry. The ionic concentrations (calcium, magnesium, sodium, chloride and nitrate) were acceptable and conformed to guideline values. The aquatic macro-invertebrate and habitat quality survey indicated that most of the sampling sites could be described as good. Sampling site 2 (next to reduction works) was classified as poor. This is the result of mining activity at this specific site situated at the rock dump at Peach Tree Creek. The extensive disturbance of the habitat is the result of 130 years of mining activities. The metal concentrations in the Blyde River exceeded the guideline limits, except for manganese. Aluminium toxicity is pH dependent, and increases with a decrease in the pH. The alkaline pH in the Blyde River acts as a buffer against the aluminium toxicity. The lead concentration in the Blyde River exceeded the Department of Water Affairs and Forestry guideline limit. Lead is hazardous to most forms of life. Zinc is toxic to fish and aquatic organisms at relatively low concentrations. Although nickel is a natural element of the earth and water, mining activities cause nickel emissions and an increase in the nickel concentrations in water systems. Copper is regarded as a highly toxic metal if present in high concentrations. Iron is not easily absorbed by aquatic organisms and because of its limited toxicity and bioavailability, described as a noncritical element. Chromium is biologically inert. Despite of a lack of information on the concentrations of metals in the Blyde River before the onset of mining activities at Pilgrim's Rest, it is clear that the extensive disturbance of the habitat at Peach Tree Creek and Vaalhoek, and to a lesser extent at Delvers' Creek exists. Present and past mining activities in the Pilgrim's Rest area resulted in the deterioration of the water quality in the Blyde River. Rehabilitation of the area around the rock dump at Peach Tree Creek will have to be done to prevent seepage from the rock dump and disturbed area to the river. Measures, such as the construction of paddocks and berm walls to collect seepage before it reaches the river, will have to be implemented. The water will then have to be treated before releasing it into the river. The acute, sub-lethal toxicity tests with nickel and lead were conducted based on the concentrations as derived from water samples taken from the Blyde River, during the monitoring phase of the project. The results of the blood physiological experimentation indicated that normal physiological functioning were disturbed when fish were exposed to sub-lethal concentrations of lead and nickel. Results indicated that stimulation of the immune system, osmotic stress and hypoxic conditions arise after lead and nickel exposure. Hypoxia arises because of a deficiency in the amount of oxygen reaching bodily tissues. Osmotic stress is a result of affected gill and kidney functioning. The metabolic variables indicated that the metabolism of trout was affected, because of stress associated with metal exposure. The nervous system functioning was also, affected, as derived from the enzymatic variables. Taking these factors into consideration, the normal functioning and survival of rainbow trout (Oncorhynchus mykiss) is hindered. The acute, lethal toxicity tests of nickel on rainbow trout (Oncorhynchus mykiss) and chubby head barb (Barbus anoplus) were performed using nickel concentrations as determined in the Blyde River. The 100% mortalities recorded, when exposing the fish to these concentrations, indicated that the Blyde River provides a buffer action against the toxic effect of nickel on the aquatic organisms. Should this buffer action be disturbed, for instance a sudden drop in water pH, the toxicity of nickel will increase and have detrimental effects on the aquatic organisms. Further deterioration of the water quality in the Blyde River should be avoided at all cost. Large scale yellow fish (Barbus marequensis) were only found at sites below sampling site no 8, which is alarming and a further confirmation of habitat degradation. To prevent further degradation of the water quality in the Blyde River annual biomonitoring in conjunction with experimental studies are suggested to obtain information, which enables effective managerial decision making. Measurements should be taken to reduce the impacts of mining and agricultural activities, if future studies indicate further water quality degradation. Objectives regarding the health of the aquatic environment should be set and actions taken to prevent the impactors from doing further harm. The Pilgrim's Rest area can be developed for Eco-tourism, and therefore the aim should be to create awareness of the river and its surroundings and involve people in the conservation thereof.

M.Sc. / The Kruger National Park is internationally one of the best known conservation areas. The perennial rivers draining eastward towards and through the park are of great importance in maintaining a healthy ecosystem. The Olifants River catchment is the largest of all the rivers flowing through the Kruger National Park. Although this river has ceased flow for three days in 1968, problems experienced in the Olifants River are of a qualitative rather than a quantitative nature. Several factors contribute to the deteriorating water quality of the Olifants River. Urbanization, agricultural, industrial and mining activities in the Phalaborwa area pose a threat to the lower parts of the Olifants River. Pollution has on several occasions lead to mortalities of populations of fish in these parts...

M.Sc. Aquatic Health) / The Klip River runs past heavy urbanization and industrialization as a consequence it is possibly one of the most abused river systems in Gauteng and perhaps the country as a whole. Eight sites were selected along the course of the Klip River for biomonitoring purposes. The sites were selected to represent the upper, middle and lower reaches of the river, while sites representing point source pollution sources were also included. Various biomonitoring techniques have been included to determine the present ecological state of the Klip River. This includes biotic indices to assess the ecological integrity of the fish and invertebrate communities and the habitat. In addition, fish health was assessed using a variety of histological, biomarker and bioaccumulation based assessments. From the results it is evident that the sites on the Klip River represent the three main regions of a river including headwaters, middle reaches and a mature river. These natural changes in river ecology also caused natural variations in the habitat availability and the resultant biotic communities. There were, however, many changes not related to these natural variations but rather the numerous anthropogenic activities present on the river. The most noticeable change has occurred due to alteration in the flow regime. These changes are brought about by the many weirs and bridges in the system, return flow from the numerous settlements and agricultural activities and the various WWTW. These alterations in flow have caused serious erosion of the stream banks and may lead to siltation of the system. It is clear from the results of the sediment particle size analysis that there is an increase in the percentage contribution of medium and very fine sand below site 3. This is a good indication that the increased flow below the Olifantsvlei WWTW is already causing siltation. Ultimately this can lead to loss of riffle habitat within the river. These flow alterations have also caused an alteration to habitat availability and quality and as a result caused a modified invertebrate community. The macroinvertebrate community at all the sites (below site 1) consisted of taxa that are tolerant to pollution. This is also reflected in the poor SASS 5 and ASPT scores observed at the various sites. These tolerant organisms probably occur in the system due to an altered habitat template and a change in water quality. It is important to note that although the values obtained for the water quality variables are within the TWQR that the oxygen saturation at some sites decreased. These sites included the sites below the Olifantsvlei WWTW, after the confluence with the Rietspruit and the last monitoring site. The Fish Health Assessment Index scores were the highest at site 3 and decreased to site 8. This indicated that the fish condition improved from site 3 to site 8. However, there was a large variation in the index scores from the individual specimens. The results of this assessment cannot be compared to other studies as no fish health assessment index has been applied on the Klip River. This study will serve as a baseline assessment for future studies of the fish health of the Klip River. The results of the metal analysis in the fish muscle tissue indicated relatively low levels that correspond to levels measured by Kotze (1999) while still being lower than fish sampled from the polluted Olifants River. It is therefore recommended that further studies be completed on the fish health of the Klip River and that the fish health of specimens in the Klip River is compared to those of the Vaal River to determine the impact of the Klip River system on the Vaal River. As it has become clear that the Rietspruit also influences the water quality of the Klip River it is recommended that further studies be completed on the Rietspruit to determine the cause of the impacts. Because the histological alterations identified may be the result of a range of different biological and/or chemical stressors, it is difficult to assign specific causative agents for the various alterations identified. Based on the selected parameters investigated, the results show that fish in the Klip River appears to be in a relatively healthy condition and the organs seem to be in a functional state. Establishing a histology-based monitoring programme for fish health in the Klip River, by incorporating appropriate sample sizes and various fish species is recommended. Monitoring of biological responses for assessing the significance of pollutants has become a reasonable measurement in biomonitoring, and use of biomarker responses has played a significant role in this aspect. However, no biomarker has been validated as a unique tool to determine the effects of pollutants on organisms. Furthermore, it is necessary to understand how bioaccumulation and biomarkers relate to each other on exposure to specific pollutants and how it varies between species, to interpret the effects of pollutant exposure in both the field and laboratory. The results obtained in this study indicate that there are definite impacts on the entire system, although these have not altered fish biology and functionality to a large extent. However, sample size should be considered when evaluating individual biomarker responses, as a larger sample size will be more representative of the resident fish community’s response to the pollutants and other stressors. It is difficult to assign specific stressors for the various biomarker responses identified. It is recommended that further biomarker studies be undertaken on the Klip River to increase the level of confidence in the results obtained.