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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Biomonitoring of heavy metals in the Eerste River catchment area

Elmayhob, Esam S. A. January 2020 (has links)
Philosophiae Doctor - PhD / The risk of increasing global pollution dictates the need to understand environmental processes and develop innovative ways to monitor pollution levels and address associated problems. In order to address this need, this study used a selection of plants leaves (Commelina benghalesis, Paspalum urvillei, Persicaria lapathifolia and Salix babylonica) as biomonitors to assess the state of the environment, more specifically the concentration of certain heavy metal pollutants (Cu, Zn, Fe, Ni, Pb and Cd) of river water and soils in the Eerste River catchment, Western Cape, South Africa.
2

Evaluation of macro-invertebrates as bio-indicators of water quality and the assessment of the impact of the Klein Plaas dam on the Eerste River

Bredenhand, Emile 12 1900 (has links)
Thesis (MScAgric (Conservation Ecology and Entomology)--University of Stellenbosch, 2005. / A semi-arid country, like South Africa, with unpredictable seasonal rainfall, is subject to great scarcity in water and an ever-increasing demand from the rising human population. Therefore, efficient reservoirs as well as monitoring methods are needed to manage the South African water supply. This study was undertaken on the Eerste River in the Western Cape, South Africa, focusing on the impact of the Klein Plaas dam system on the benthic macroinvertebrates. The study also examined the use of benthic macroinvertebrates as bioindicators of water quality with special reference to the South African Scoring System Version 5(SASS5) that is currently being used nationally. The impoundment of the water, as well as the inter-basin transfer programme and the experimental cage-culture trout farm, all play a significant role in the disturbance impact of the dam on the Eerste River system. The disturbance is manifested as a drop in water quality that can be seen in the distribution of keystone species, changes in the riparian vegetation, as well as in physical-, chemical-, and biomonitoring evaluations. The study also indicated that the SASS5 is effective, but needs some adjustments, such as inclusion of a prediction phase, finer spatial-scale methodologies and greater consideration of the rarity of species.
3

Water quality trends in the Eerste River, Western Cape, 1990 - 2005.

Ngwenya, Faith January 2006 (has links)
<p>The Eerste River is a river system which has, over the years, been subjected to human interference. The purpose of this study was to investigatge temporal and spatial trends in the water quality of the Eerste River between 1990 and 2005. The study results revealed that the major trends in the water quality of the Eerste River are more spatial than temporal.</p>
4

Water quality trends in the Eerste River, Western Cape, 1990 - 2005.

Ngwenya, Faith January 2006 (has links)
<p>The Eerste River is a river system which has, over the years, been subjected to human interference. The purpose of this study was to investigatge temporal and spatial trends in the water quality of the Eerste River between 1990 and 2005. The study results revealed that the major trends in the water quality of the Eerste River are more spatial than temporal.</p>
5

Water quality trends in the Eerste River, Western Cape, 1990 - 2005

Ngwenya, Faith January 2006 (has links)
Magister Scientiae (Integrated Water Resource Management) / The Eerste River is a river system which has, over the years, been subjected to human interference. The purpose of this study was to investigatge temporal and spatial trends in the water quality of the Eerste River between 1990 and 2005. The study results revealed that the major trends in the water quality of the Eerste River are more spatial than temporal. / South Africa
6

Institutional overlaps in water management in the Eerste River catchment

Nleya, Ndodana January 2005 (has links)
Magister Philosophiae (Integrated Water Resource Management) / In this minithesis I have investigated overlapping mandates as a source of management failure in water management in South Africa in general and Eerste River Catchment in particular. I analysed major legislation which deals with water management to find out how duties and responsibilities are apportioned in the various pieces of legislation. I also undertook an exercise of evaluating roles and responsibilities played by various organs of state in water management from national government, Provincial Government of the Western Cape through to local government, in this case the Municipality of Stellenbosch and the City of Cape Town. It emerged that there were a number of areas of overlap, ambiguously defined mandates, conflict and that these were impeding on decision making in water management. In order to test the framework built above, I then applied it in the Plankenbrug River, a tributary of the Eerste River. Through analysis of newspaper clippings over a period of 4 years I was able to reconstruct conflict over ill-defined mandates in the various aspects of the management of the catchment which showed that there were differences in roles of the different state organs operating in the catchment. Water management conflict emanated from lack of congruence in the various legislation and differences in the interpretation of legislation. The various state organs seem to be aware of the constitutional duty of cooperative government that engenders state organs to work co-operatively in order to meet their developmental mandates. It seems however that the state organs were merely interested to be seen to be in conformity with this duty more than actually solving the issue as this was seen as something to be tackled at a higher level. / South Africa
7

Institutional overlaps in water management in the Eerste River Catchment.

Nleya, Ndodana January 2005 (has links)
In this minithesis I have investigated overlapping mandates as a source of management failure in water management in South Africa in general and Eerste River Catchment in particular. I analysed major legislation which deals with water management to find out how duties and responsibilities are apportioned in the various pieces of legislation. I also undertook an exercise of evaluating roles and responsibilities played by various organs of state in water management from national government, Provincial Government of the Western Cape through to local government, in this case the Municipality of Stellenbosch and the City of Cape Town. It emerged that there were a number of areas of overlap, ambiguously defined mandates, conflict and that these were impeding on decision making in water management. In order to test the framework built above, I then applied it in the Plankenbrug River, a tributary of the Eerste River. Through analysis of newspaper clippings over a period of 4 years I was able to reconstruct conflict over ill-defined mandates in the various aspects of the management of the catchment which showed that<br /> there were differences in roles of the different state organs operating in the catchment. Water management conflict emanated from lack of congruence in the various legislation and differences in the interpretation of legislation. The various state organs seem to be aware of the constitutional duty of cooperative government that engenders state organs to work co-operatively in order to meet their developmental mandates. It seems however that the state organs were merely interested to be seen to be in conformity with this duty more than actually solving the issue as this was seen as something to be tackled at a higher level.
8

Institutional overlaps in water management in the Eerste River Catchment.

Nleya, Ndodana January 2005 (has links)
In this minithesis I have investigated overlapping mandates as a source of management failure in water management in South Africa in general and Eerste River Catchment in particular. I analysed major legislation which deals with water management to find out how duties and responsibilities are apportioned in the various pieces of legislation. I also undertook an exercise of evaluating roles and responsibilities played by various organs of state in water management from national government, Provincial Government of the Western Cape through to local government, in this case the Municipality of Stellenbosch and the City of Cape Town. It emerged that there were a number of areas of overlap, ambiguously defined mandates, conflict and that these were impeding on decision making in water management. In order to test the framework built above, I then applied it in the Plankenbrug River, a tributary of the Eerste River. Through analysis of newspaper clippings over a period of 4 years I was able to reconstruct conflict over ill-defined mandates in the various aspects of the management of the catchment which showed that<br /> there were differences in roles of the different state organs operating in the catchment. Water management conflict emanated from lack of congruence in the various legislation and differences in the interpretation of legislation. The various state organs seem to be aware of the constitutional duty of cooperative government that engenders state organs to work co-operatively in order to meet their developmental mandates. It seems however that the state organs were merely interested to be seen to be in conformity with this duty more than actually solving the issue as this was seen as something to be tackled at a higher level.
9

An assessment of water quality and endocrine disruption activities in the Eerste/Kuils River catchment system, Western Cape, South Africa

Fourie, Shani 04 1900 (has links)
Thesis (MSc)--University of Stellenbosch, 2005. / ENGLISH ABSTRACT: Water quality analysis forms the basis in assessing and monitoring catchments. As urban development continuously increase, pollution sources increase in either point source (wastewater treatment works, industrial effluents) and/or non-point source origin (storm water discharge, domestic pollutants), accumulating pollutants in the environment. It was only recently discovered that certain pollutants have subtle disrupting effects on the endocrine system resulting in health related problems associated with the reproductive system and thyroid system (growth and development) of animals and potentially humans. Natural water resource management proves to include limited biological assays measuring endpoints for cytoxicity, inflammatory activity and endocrine disruption. The broad objective of this study was therefore to include several bioassays, not normally used in municipal (City of Cape Town) monitoring programmes, along with water quality data collected by the City of Cape Town. The Eerste/Kuils River catchment system, Western Cape, under the auspices of the City of Cape Town was chosen, and although this catchment does not contribute to drinking water resources, is subjected to a range of anthropogenic influences (industrial effluents, household wastewater, agricultural runoff). Within the short time-frame available for this study (six months) two months, July (following a dry summer and autumn season) and October (following a wet winter and early spring season) were selected for water quality monitoring. Spatial variation (with relevance to specific point and non-point contamination) among sampling sites were also obtained by choosing several (n=10) along the catchment. Specific aim of the study therefore included: Firstly (Chapter 2), the use of in vitro bioassays, lactate-dehydrolises assay (LDH) for cytotoxic activity, pro-inflammatory hormone Interleukin-6 (IL-6) secretion by human blood cells and a specific Salmonella ELISA for faecal contamination, in conjunction with routine chemical and biological (mostly microbiological) monitoring activities. The study indicated significant variation among sites in all microbiological measures as well in IL-6 secretion and Salmonella presence. Between months, variations were also evident in certain variables. Secondly (Chapter 3), two bioassays using the yolk precursor protein, vitellogenin (Vtg) as endpoint was implemented in a) an in vitro Xenopus laevis liver slice assay (five day exposure) and b) an in vivo Zebrafish (Danio rerio) bioassay (seven day exposure) assessing estrogenic activity in the Eerste/Kuils River catchment. Although estrogen spiked positive control water samples stimulated Vtg production in vitro as well as in vivo, no dramatic estrogenic activity was measured at any of the selected sites. Thirdly (Chapter 4), a bioassay using the thyroid controlled metamorphosis in Xenopus laevis tadpoles to assess effects on the thyroid hormonal system was implemented. Thyroid stimulatory activity, compared with a negative control sample, was measured at two sites along the catchment. Although the practical implementation of the tadpole semi-static exposure protocol (water replacement) proved to be labour intensive, all the added bioassays proved to be valuable tools to add valuable information regarding water quality. It is clear that more research related to anthropogenic influences along the Eerste/Kuils River catchment system are needed, specifically in monitoring monthly variations to better understand annual variation in several of the endpoints studied. / AFRIKAANSE OPSOMMING: Waterkwaliteit vorm die basis vir die evaluering en monitering van opvangsgebiede. Voortdurende stedelike ontwikkeling gee aanleiding tot ‘n toename in die voorkoms van besoedelstowwe in die natuurlike omgewing deur gelokaliseerde (punt) bronne (rioolwerke/industriële uitvloeisel) en/of nie gelokaliseerde (nie punt) bronne (vloed uitlaat/huishoudelike uitvloeisels) van besoedeling. Dit het onlangs aan die lig gekom dat van hierdie chemise besoedelstowwe subtiel die endokriene sisteem versteur en so aanleiding gee tot gesondheidsprobleme in terme van die voortplantingsisteem en tiroied sisteem (groei en ontwikkeling) by diere en moontlik ook die mens. Daar is beperkte gebruik van biologiese toetse wat inligting verskaf oor sitotoksiteit, inflammatoriese aktiwiteit en endokriene versteuring. Die doel van hierdie studie was dus om van hierdie biologiese toetse, wat normaalweg nie deel uitmaak van die roetine munisipale (Stad van Kaapstad) opvangsgebied monitering nie, gebruik te maak. Die Eerste-, Kuilsrivier, Wes Kaap, onder beheer van Stad Kaapstad is gekies en alhoewel die opvangsgebied nie water bydra tot drinkwaterbronne nie, word die opvangsgebied beïnvloed deur verskeie mensgemaakte bronne van besoedeling (afloop vanuit omliggende lanbougebiede). Binne die kort tydsraamwerk van die projek (ses maande) is besluit om twee maande, Julie (volg ‘n droë somer en herfs seisoen) en Oktober (volg ‘n nat winter en vroeë lente seisoen) vir water kwaliteit monitering te kies. Ruimtelike variasie langs die loop van die opvangsgebied is ingesluit deur moniteringspunte (n=10), met in ag name van die potensiële besoedelingsbronne. Spesifieke doelwitte van die projek sluit in: Eerstens (Hoofstuk 2), om die in vitro biotoetse, laktaat hidrolise (LDH) vir sitotoksisiteit, proinflammatoriese hormoon Interleuikin-6 (IL-6) vir inflammatoriese aktiwiteit, vrygestel deur menslike bloedselle en ‘n Salmonella ELISA vir ontlasting besoedeling saam met bestaande chemise en biologiese (hoofsaaklik migrobiologiese) veranderlikes te gebruik. Die studie het getoon dat beduidende variasie in alle mikrobiologiese toetse asook IL-6 vrystelling en Salmonella voorkoms bestaan het tussen versamelpunte. Maandelikse variasie in sekere van die veranderlikes het ook voorgekom. Tweedens (Hoofstuk 3), is twee biotoetse wat die dooiervoorloperproteïen, vitellogeen (Vtg) as eindpunt gebruik geimplimenteer in a) ‘n in vitro Xenopus laevis lewersnit biotoets (vyf dag blootstelling) en b) ‘n in vivo Zebravis (Danio rerio) biotoets (sewe dag blootstelling) om estrogenisiteit in die Eerste-, Kuilsrivier opvangsgebied te evalueer. Alhoewel, die estrogeen behandelde positiewe kontrole water monsters Vtg produksie veroorsaak het in beide die in vitro lewer-kulture en in vivo vistoets, is geen dramatiess estrogeniese aktiwiteit by enige van die moniteringspunte gevind nie. Derdens (Hoofstuk 4), is ‘n biotoets wat die tiroïedbeheerde metamorfose in Xenopus laevis paddavisse gebruik om effekte op die tiroïedsisteem te evalueer. Die differensiële stimulering (versnelling), in vergelyking met ‘n negatiewe kontrole watermonster, van die tiroied sisteem is by twee moniteringspunte in die opvangsgebied waargeneem. Alhoewel die praktiese implementering van die paddavis semi-statiese (water word gereeld vervang) biotoets arbeidsintensief is, het alle bykomstige biotoetse waardevolle bykomstige inligting oor water kwaliteit verskaf wat ‘n belangrike bydrae tot ingeligte bestuursbesluite kan verleen. Dit is duidelik dat meer navorsing int verband met die menslike invloed langs die Eerste-, Kuilsrivier opvangsgebied nodig is, veral met maandlikse monitering vir seisoenale veranderinge.
10

The uptake and distribution of selected heavy metals in the freshwater crab, Potamonautes perlatus (Milne Edwards), in the Eerste River, Western Cape

Snyman, Reinette Georgenie 12 1900 (has links)
Thesis (MScAgric (Zoology))--University of Stellenbosch, 1996. / A number of studies on the general physico-chemical character of the Eerste River, Western Cape, had previously been done, but the problem of heavy metal pollution had, by 1993, not been addressed. A study was therefore undertaken from 1993-1995 in order to investigate these aspects. Since several researchers have shown that freshwater crabs accumulate certain heavy metals in their bodies and may therefore be used as monitors of environmental heavy metal pollution, the present study concentrated mainly on metal concentrations (Mn, Zn, Cu, Pb and Cd) in the local freshwater crab species, Potamonautes perlatus, and its possible use as biomonitor in the Eerste River. Two localities in the Eerste River were chosen,. in order to make comparisons, namely a relatively uncontaminated site in the Assegaaibosch Nature Reserve, Jonkershoek, and a visibly polluted site downstream from Stellenbosch, behind Stellenbosch Farmers' Winery (SFW). Crabs, water and sediment samples were collected seasonally at both localities, and metal concentrations thereof determined by atomic absorption spectrophotometry. The results showed that the Eerste River down to the SFW locality is still relatively unpolluted in terms of heavy metals. It was, however, clear that runoff from the Stellenbosch municipal, industrial and agricultural areas do have an influence on other physico-chemical features of the river. The concentrations of heavy metals in whole crabs, tissues and carapace showed that Zn concentration was well regulated in P. perlatus from both localities, Mn and Cu were accumulated in individuals from SFW, and Pb and Cd accumulated in both populations. Compartmentalization of heavy metals was shown to occur in P. perlatus: the carapace was found to be the most important storage site for Mn, Zn and Pb, the carapace and gonads equally important for Cd storage, and the digestive gland the most important site for Cu storage. Whereas gender was shown, generally, to be of little importance in heavy metal uptake in P. perlatus, crab body size and seasonality were both shown to influence heavy metal uptake to some extent. However, only summer peaks in whole crab, carapace and tissue manganese concentrations were shown to correlate with peaks in environmental Mn concentrations. It was concluded that P. perlatus would possibly only be a Suitable monitor of environmental Mn, Pb and Cd pollution, although there is no guarantee that the crab body would accurately reflect environmental concentrations. It was also ascertained that, since a study of the sperm ultrastructure of P. perlatus showed a significantly larger number of abnormal spermatozoa in male crabs from ,SFW, and since these observed differences could possibly be related to heavy metal exposure, the sperm of this species might be a more reliable indicator of heavy metal pollution. It was finally concluded that more intensive research need to be undertaken on various aspects, especially the use of the spermatozoon as indicator of environmental heavy metal pollution, and that the results of the present study could serve as a basis for future studies.

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