Dissertations / Theses: 'Olifants River'

1

Soutschka, Nadine. "Community-based resource use monitoring at the Olifants River Estuary." Master's thesis, University of Cape Town, 2014. http://hdl.handle.net/11427/13276.

Full text

Abstract:

Includes bibliographical references. Small-scale fisheries are increasingly seen as complex socio-ecological systems, requiring alternative management approaches. These new approaches to natural resource management advocate the inclusion of resource users in all aspects of management, including monitoring. Research suggests that involvement of local resource users in resource monitoring is beneficial as it promotes local empowerment, community stewardship and contributes to social and resource sustainability. This study aims to contribute knowledge about the nature and effectiveness of a community-based fisheries monitoring system at the Olifants River estuary in South Africa and documents lessons learned. This research reports on the revision and revitalisation of an existing community monitoring program operating at the Olifants River estuary and presents the results of data gathered from this one year monitoring program. It also compares these results with data gathered from previous years when the monitoring system was operational. Finally, the strengths and weaknesses of the community monitoring system are discussed. A participatory research approach was followed by employing members of the Olifants River community as catch monitors and working closely with the fishers and monitors to better understand their perceptions of the strengths and weaknesses of the monitoring system. Findings of this research suggest that despite weaknesses in the community monitoring system, the data gathered provided useful information about the catch effort trends for the fishery for the year under consideration and also enabled some comparisons of selected fisheries indicators with previous data to be made. These comparisons suggest that catch per unit effort for the target species, harder (Liza richardsonii) is stable and there is no indication of overexploitation of this resource. A key weakness of the monitoring is that it is ad hoc and funding is insecure. Due to poverty levels in the community, local monitors may take up short-term employment opportunities in the community and thus neglect their monitoring responsibilities. This means that the data sets are not comprehensive. Key strengths include the fact that it is simple, cost effective and can be implemented by community members. Furthermore, local involvement in resource monitoring builds capacity and skills as well as local empowerment. Finally, this research contributes to knowledge that can inform the implementation of community monitoring programs proposed by the recently published Small-scale fishing policy of South Africa. Key Words: Small-scale fisheries; natural resource management; participation, community monitoring, local empowerment.

APA, Harvard, Vancouver, ISO, and other styles

2

Mthombeni, Vusi Gedla. "The biology of austroglanis gilli and austroglanis barnardi (siluriformes : austroglanididae) in the Olifants River system, South Africa." Thesis, Rhodes University, 2010. http://hdl.handle.net/10962/d1015222.

Full text

Abstract:

Austroglanis gilli and A. barnardi are endemic to the Clanwilliam-Olifants System in the Western Cape, South Africa. The populations of each of these species are considered to be threatened by various anthropogenic activities, which include inappropriate agricultural practice and impacts of alien invasive fish species. The purpose of this thesis was to assess the life-history of these two endangered species in order to contribute to understanding their biology. Such information is vital for the development of strategies for their conservation. Marginal zone and marginal increment analyses from sectioned lapilliar otoliths of both A. gilli and A. barnardi showed a unimodal peak, suggesting a single annulus formation. The oldest specimens of A. gilli and A. barnardi were 12+ and 14+ years, respectively. The growth of A. gilli and A. barnardi was relatively slow and was best described by the von Bertalanffy growth curve as: L, = 131.56(1 - exp(- 0.27(t - 1.18 ))) for male and L, = 113.86(1 - exp(- 0.43(1- 0.74))) for female A. gilli from the Rondegat River. In the Noordhoeks River, growth was L, = 99.67(1 - exp(- 0.53(t - 0.35))) for male and L, = 96.60(1 - exp(- 0.64(t - 0.11 ))) for female A. gilli, and L, =71.02(1-exp(-0.26(1-3.07))) and L, = 69.50(1-exp(-0.36(1 - 1.88))) for male and female A. barnardi, respectively. The average natural mortality for the combined sexes was estimated using catch curve analysis at 0.37 ± 0.12 per year for A. gilli from the Rondegat River, and at 0.71 ± 0.05 and 0.39 ± 0.04 per year for A. gilli and A. barnardi from the Noordhoeks River, respectively. For A. gilli in the Rondegat River, the first maturity was estimated at 3.3 years (97.3 mm SL) for males and 3.1 years (94.3 mm SL) for females. In the Noordhoeks River, the first maturity for A. gilli was estimated at 2.0 years (71.9 mm SL) for males and 1.7 (66.4 mm SL) for females, and for A. barnardi at 2.0 (55.0 nun SL) for males and 2.9 years (58.9 mm SL) for females. Maturity corresponded closely to the asymptotic sizes from the von Bertalanffy curves, suggesting a shift in energy use from somatic growth to gonad development. Macroscopic assessment of the state of gonads, the Ganado-somatic index and histological examinations revealed that both A. gilli and A. barnardi have a single spawning season. The presence of oocytes in different stages of development in each of the ovaries of mature females collected between November and January suggested asynchronous, iteroperous serial spawning. The resorption of yolk was observed from ovaries collected between February and March and no vitellogenic oocyte was visible from ovaries collected between April and August. A similar trend was observed for males, with spermatozoa filling the lumen between November and January and some residual spermatozoa being present in the lumens soon after the breeding season. Spermatocytes and spermatids were dominant in the testes until October. An Index of Relative Importance revealed that A. gilli feeds predominantly on the benthic macroinvertebrate larvae of Ephemeroptera (particularly Baetidae), Diptera (particularly Chironomidae and Simuliidae) and Trichoptera. Austroglanis barnardi feeds predominantly on dipteran larvae (particularly Chironornidae and Simuliidae). Chi square contingency tables showed a significant difference in the dominant prey items of A. gilli and A. barnardi in the Noordhoeks River (X₂= 53.79, d.f. = 4, p > 0.001) and A. gilli between Rondegat and Noordhoeks rivers (x₂ = 34.74, d.f. = 4, p > 0.001). The Spearman's rank correlation test showed no shifts in the diet of A. barnardi from Noordhoeks River and A. gilli from Rondegat River with a change in size and season (p>O.OS). However, there was a shift in the diet of A. gilli from the Noordhoeks River which could suggest a distinct patchiness of benthic macroinvertebrates between the riffle feeding areas used by juveniles and other biotopes used by adults. The occurrence, in stomach contents, of other prey items from a wide variety of taxa and the presence of allochthonous material from the terrestrial environment could suggest an opportunistic feeding guild for both Austroglanis species. The life-history traits of A. gilli and A. barnardi, which are charaterized by slow growth, long life span and low relative fecundity, indicate that both species are relatively precocial and K-selected. The population of a precocial species is relatively stable and if population numbers were to be greatly reduced, they would require a long time to rebuild. An urgent conservation intervention is therefore recommended for Austroglanis spp. so as to maintain the diversity of populations within these species. The creation of protected river reserves and raising public conservation awareness may minimise activities that result in altered river hydrology and the destruction of complex benthic habitats.

APA, Harvard, Vancouver, ISO, and other styles

3

Hallinan, Emily Sarah. "Stone age landscape use in the Olifants River Valley, Western Cape." Master's thesis, University of Cape Town, 2013. http://hdl.handle.net/11427/6605.

Full text

Abstract:

This thesis investigates changing patterns of landscape use throughout the Earlier (ESA), Middle (MSA) and Later Stone Ages (LSA) in the Olifants River Valley in the Western Cape, South Africa. Stone Age surface assemblages are all too often neglected in favour of stratified, datable cave sequences, overlooking important insights into changing behavioural patterns at a broader scale. The Olifants River Valley offers the opportunity for integrating a rich surface lithic record with excavated rock shelter occupation dating from the LSA and extending back into the early part of the MSA. This thesis approaches Stone Age landscape use with reference to a hypothesis proposed by Hilary Deacon, framing the MSA within the context of earlier and later patterns of behaviour. Based on observations from sites across South Africa, Deacon described ESA landscape use as stenotopic, occupying a narrow ecological niche focused on permanent water sources, and LSA landscape use as eurytopic, making use of a much broader range of habitats but with a specific focus on rock shelters as domestic sites. Deacon suggested that the intervening MSA, in its later stages, shows a pattern that anticipated LSA landscape use, with an increasing emphasis on caves and a wider-ranging exploitation of resources across different environmental zones. Surface surveys were carried out in the Olifants River Valley, mapping temporally diagnostic artefacts and their association with different topographic features. In this thesis, I test Deacon's model and show that it can be applied to the study area, observing distinctive preferences for certain sites and raw materials, and approaching changes in patterns of artefact discard from a technological perspective.

APA, Harvard, Vancouver, ISO, and other styles

4

Swartz, Ernst Roelof. "Population genetics of Pseudobarbus phlegethon, Barbus calidus and Barbus erubescens (Teleostei: Cyprinidae) of the Olifants River System, Western Cape Province." Thesis, Stellenbosch : Stellenbosch University, 2000. http://hdl.handle.net/10019.1/51876.

Full text

Abstract:

Thesis (MSc)--University of Stellenbosch, 2000. ENGLISH ABSTRACT: Endemic redfin minnows of the Olifants River System are under threat of extinction, mainly because of alien predatory fish, water extraction and pollution. The taxonomic position and biogeography of redfins in relation to other barbs are uncertain. Enzyme electrophoresis was employed to assess genetic differentiation within and among certain Barbus and Pseudobarbus taxa. Fourteen enzymes were routinely recorded from muscle tissue extracts, yielding a differential number of active loci. The latter is due to different ploidy levels. Polyploid species showed fewer loci than the tetraploid or hexaploid number of loci expected just after the polyploidy event. Barbus aenus (hexaploid) expressed 6.2 % of the duplicated loci expected after the hexaploidy event. The tetraploid Pseudobarbus and serrated Barbus spp., expressed 37.5 % and 31.2 % of the duplicated loci expected after the tetraploidy event, respectively. This suggests that the ploidy event in Barbus aenus is more ancient than in the above-mentioned tetraploid barbs. The similar amount of diploidization in Pseudobarbus and tetraploid serrated Barbus spp. investigated, suggests a shared ploidy event between these two lineages. The number of active loci is apparently not a good indication of the ploidy level of African barbs, as hexaploid Barbus aenus expressed less active loci than the tetraploid barbs investigated. Initial screening of allozyme loci yielded fixed allele differences at 22 loci, but polymorphism only at seven. This suggests more potential for delineating species boundaries than for assessing gene flow and genetic diversity of populations. Genetic differentiation within and among populations of Pseudobarbus phlegethon, Barbus calidus and Barbus erubescens were investigated by screening 27 allozyme loci. A clear divergence between Pseudobarbus phlegethon populations from the Olifants and Doring Rivers was found (Nei's unbiased genetic distance = 0.355; F-statistic for subpopulation against the total = 0.877). Preference and adaptation for mountain stream habitat might explain the past isolation and subsequent divergence of Pseudobarbus phlegethon populations between these two rivers. Barbus calidus was genetically homogenous over its distribution (Nei's unbiased genetic distance = 0-0.009; F-statistic for subpopulation against the total = 0.135). It is proposed that Barbus calidus is better adapted than Pseudobarbus phlegethon to disperse through the main stream. The genetic divergence between Barbus calidus and Barbus erubescens (Nei's unbiased genetic distance = 0.063) is characteristic of conspecific populations. There seems to have been a loss of genetic diversity in redfin populations of the Doring River tributaries (heterozygosity = 0-0.01), compared to the redfin populations of the Olifants River tributaries (heterozygosity = 0.01- 0.04). From phylogenetic analysis ofallozyme characters, it seems as if the serrated tetraploid barbs from South Africa is the sister-group of Pseudobarbus, whilst Barbus anoplus was rejected as a sister-species for the latter. Barbus calidus, Barbus erubescens and Barbus serra were found to be closely related to each other. The ancestor of the redfins seems to have been present in the Cape Fold Mountains since at least the late- Tertiary. On the basis of distributional and allozyme information, conservation units reflecting historical divergence, historical gene flow and current gene flow were identified as Evolutionarily Significant Units, Historical Management Units and Current Management Units respectively. The Olifants and Doring River populations of Pseudobarbus phlegethon should be recognized as two distinct Evolutionarily Significant Units. Barbus calidus forms a separate Evolutionarily Significant Unit from Barbus erubescens. Twelve Historical Management Units and nineteen Current Management Units were recognized for redfins of the Olifants River System. The size of Current Management Units should be expanded and secured to prevent loss of genetic diversity. It is recommended that a recovery program of redfins should establish new populations of at least Barbus erubescens and Doring River Pseudobarbus phlegethon Evolutionarily Significant Unit. Centrarchids should be irradicated, as they are the main reason for the decline of red fins. AFRIKAANSE OPSOMMING: Die endemiese rooivlerkies van die Olifantsriviersisteem word bedreig deur uitsterwing, hoofsaaklik as gevolg van uitheemse roofvisse, water onttrekking en besoedeling. Die taksonomiese posisie en biogeografie van rooivlerkies in verhouding met ander barbusse is onseker. Ensiemelektroferese is gebruik om genetiese differensiasie binne en tussen sekere Barbus en Pseudobarbus taksa te bepaal. Veertien ensieme, wat verskillende hoeveelhede aktiewe lokusse gelewer het, is op roetine basis waargeneem uit spierweefselekstrakte. Die verskillende hoeveelhede aktiewe lokusse wat waargeneem is, is as gevolg van verskillende ploied vlakke. Poliploïede spesies het minder lokusse getoon as wat verwag sou word net na die tetraploïede ofheksaploïede gebeurtenisse. Barbus aenus (heksaploïed) het 6.2% van die gedupliseerde lokusse, wat verwag sou word na die heksaploiede gebeurtenis, uitgedruk. Die tetraploïede Pseudobarbus en saagagtige Barbus spp. het 37.5% en 3l.2% respektiewelik van die gedupliseerde lokusse, wat verwag sou word na die tetraploïede gebeurtenis, uitgedruk. Dit dui daarop dat die ploïede gebeurtenis in Barbus aenus meer histories as in die bogenoemde tetraploïede barbusse. Die soortgelyke hoeveelheid diploïedisasie in Pseudobarbus en tetraploïede saagagtige Barbus spp. wat ondersoek is, dui op 'n moontlike gesamentlike ploïede gebeurtenis tussen hierdie twee evolusionêre lyne. Die aantal aktiewe lokusse blyk nie 'n goeie aanduiding van die ploïed vlakke van Afrika barbusse te wees nie, aangesien die heksaploïede Barbus aenus minder lokusse as die tetraploïede barbusse wat ondersoek is, getoon het. Aanvanklike analisering van allosiem lokusse het vaste alleel verskille in 22 lokusse opgelewer, maar slegs sewe het polimorfisme getoon. Dit dui op moontlike beter potensiaalom spesie-grense vas te stel, eerder as die bepaling van genevloei of genetiese diversiteit van populasies. Genetiese differensiasie binne en tussen populasies van Pseudobarbus phlegethon, Barbus calidus en Barbus erubescens is ondersoek deur 27 allosiem lokusse te analiseer. 'n Duidelike divergensie tussen Pseudobarbus phlegethon populasies van die Olifants- en Doring- riviere is gevind (Nei se onbevooroordeelde genetiese afstand = 0.355; F-statistiek vir subpopulasie teen die totaal = 0.877). Voorkeur en aanpassing vir bergstroom habitat, mag moontlik die historiese isolasie en daaropvolgende divergensie van Pseudobarbus phlegethon populasies tussen hierdie twee riviere verduidelik. Barbus calidus was geneties homogeen oor sy verspreiding (Nei se onbevooroordeelde genetiese afstand = 0-0.009; F-statistiek vir subpopulasie teen die totaal = 0.135). Dit word voorgestel dat Barbus calidus beter aangepas is as Pseudobarbus phlegethon om deur die hoofstroom te versprei. Die genetiese divergensie tussen Barbus calidus en Barbus erubescens (Nei se onbevooroordeelde genetiese afstand = 0.063) is kenmerkend van spesiespesifieke populasies. Dit lyk of daar 'n verlies aan genetiese diversiteit in rooivlerkie populasies vanafdie Doringrivier sytakke was (heterosigositeit = 0-0.01), in vergelyking met rooivlerkie populasies vanafdie Olifantsrivier sytakke (heterosigositeit = 0.01- 0.04). Uit die filogenetiese analise van allosiem kenmerke, blyk dit dat die saagagtige tetraploiede barbusse van Suid-Afrika die sistergroep van Pseudobarbus is, terwyl Barbus anoplus verwerp word as sisterspesie vir laasgenoemde. Dit is gevind dat Barbus calidus, Barbus erubescens en Barbus serra baie naverwant aan mekaar is. Dit lyk asof die voorvader van die rooivlerkies sedert ten minste die laat-Tersiêr in die Kaapse Plooiberge aanwesig was. Bewaringseenhede wat historiese divergensie, historiese genevloei en huidige genevloei voorstel, is geidentifiseer respektiewelik as Evolusionêre Beduidende Eenhede, Historiese Bestuurseenhede en Huidige Bestuurseenhede. Dit is gedoen op grond van verspreidings- en allosieminformasie. Die Olifants en Doring populasies van Pseudobarbus phlegethon moet as twee unieke Evolusionêre Beduidende Eenhede erken word. Barbus calidus en Barbus erubescens vorm aparte Evolusionêre Beduidende Eenhede. TwaalfHistoriese Bestuurseenhede en negentien Huidige Bestuurseenhede is geidentifiseer vir rooivlerkies van die Oifantsriviersisteem. Die grootte van Huidige Bestuurseenhede moet vergroot en beveilig word om verlies van genetiese diversiteit te vermy. Dit word voorgestel dat 'n herstelprogram van rooivlerkies moet poog om nuwe populasies, van ten minste Barbus erubescens en Doringrivier Pseudobarbus phlegethon Evolusionêre Beduidende Eenhede, te vestig. Baars en blouwang sonvis moet uitgeroei word, aangesien hulle die hoofoorsaak is vir die afname van rooivlerkies.

APA, Harvard, Vancouver, ISO, and other styles

5

Taylor, Arthur. "A trace element study of sediments from the Olifants River estuary, the Berg River estuary, and the off-shore Mud Belt." Master's thesis, University of Cape Town, 2004. http://hdl.handle.net/11427/9027.

Full text

Abstract:

Includes bibliographical references (leaves 99-105). Trace elements have received increased attention since the mid-1900's. Although some studies have investigated trace element accumulation as a result of urban expansion in the Western Cape, South Africa, few have catalogued the accumulation and behavior of trace elements resulting from agricultural practices. This study investigates the distribution and behavior of trace elements for the Olifants and Berg river catchments by focusing on the sediments of the estuaries. The dominant industry in both catchments is agriculture and there exists relatively little urban sprawl. Two sediment samples taken from the offshore mud belt in the vicinity of the two river mouths were also analyzed. The sediments were analyzed for trace elements using inductively coupled plasma mass spectrometry (ICP-MS), major elements using X-ray ﬂuorescent spectroscopy (XRF), total sulfur using XRF, total and organic carbon using a C:H:N analyzer, and grain size analysis was performed (>62 μm, 38-63 μm, 2-38 μm, <2μm). The mud belt cores were dated using 14C dating. Estuarine surface waters were analyzed for trace elements, pH, dissolved oxygen (DO), electrical conductivity (EC), and temperature. The trace elements arsenic (As), cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn) were focused on. The trace element concentrations in the sediments were compared with those of soils that occur in the study area, as well as their parent materials, to determine background concentrations. The concentration proﬁles of elements with respect to depth are compared with natural deposition rates to recognize signs of recent enrichment of individual trace elements. Inter-element comparisons are made in an attempt to determine speciation. Comparison between the estuarine and mud belt sediments were made to assess the estuaries ability to ﬁlter ﬂuvial trace elements, as well as to determine the sediment contributions of the Olifants and Berg rivers to the mud belt. Statistical analysis was performed to"group sediment populations Trace element and organic matter concentrations showed strong positive correlations with ﬁne-sized particles. The mud belt sediments displayed considerably more OC than the estuarine sediments. The trace elements appear to associate predominantly with clay minerals (alumino-silicates), Fe/Mn oxides, and organic matter. Trace element correlations with S and carbonate carbon were also observed. Comparison with estimates of natural deposition rates and compositions of soils occurring in the catchments did not suggest an anthropogenic pollution input. From the data available the estuarine and Mud Belt sediments appear enriched in Cd, Cu and Zn in comparison to the background soils. The estuaries seem to effectively trap Zn and Pb, but do not capture As well. Statistical analysis suggest that, of the rock types considered, the sediments of the Olifants and Berg river estuaries and those of the off shore mud belt are most similar to sediments derived from the Malmesbury and Ecca Groups. The Olifants and Berg rivers are important sources of water for the farming community, as well as for municipal use in the Western Cape. Based on this investigation of the estuarine waters and sediments the rivers appear to be in good health in regards to trace element concentrations.

APA, Harvard, Vancouver, ISO, and other styles

6

Horwood, Owen. "The Challenge of Change : A Study of Water Governance in the Olifants River Basin, South Africa." Thesis, University of Oxford, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.517161.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

Lebepe, Jeffrey. "Assessment of the effects of environmental contaminants on feral fish populations in the Olifants river system." Thesis, University of Limpopo, 2018. http://hdl.handle.net/10386/2450.

Full text

Abstract:

Thesis (Ph.D (Zoology)) --University of Limpopo, 2018 Freshwater ecosystems are the most threatened systems globally, suffering from channel modification, over extraction of water and, of particular concern, pollution. In South Africa, Olifants River is categorised as the third most polluted river system. Acid mine drainage seeping from derelict and abandoned mines has been described as the primary stressor in the upper Olifants catchment. The increase of metal concentration in the water, sediment and fish tissues has been evident over the past few decades. As a result, there has been an increasing concern regarding the effects of increased metal concentrations on the health of fish and the safety of communities consuming fish from the polluted Olifants River system. This study used enzymatic and histopathologic biomarkers to assess the physiological response of Oreochromis mossambicus and Labeo rosae to environmental contaminants. The study further investigated the metal accumulation trend of across different fish tissues and assessed the edibility of O. mossambicus and L. rosae from Loskop and Flag Boshielo dams. Water, sediment and fish samplings were carried out concurrently during low flow and high flow seasons in 2014. Water and sediment sampling were done at the inflow, middle and dam wall. A minimum of 10 fish specimens for each species were collected from Loskop and Flag Boshielo dams during each sampling. For bioaccumulation analysis, liver, gill and muscle tissues were dissected out, wrapped with aluminium foil and frozen. Frozen samples were sent to SANAS accredited laboratory for metal analysis. For Histopathology, tissues were fixed in 10% neutral buffered formalin prior processing. Tissue processing was done at the Pathology laboratory of the University of Pretoria, Onderstepoort campus. For biomarker analysis, liver and brain tissues were fixed in liquid nitrogen in the field and transferred to the -80°C biofreezer at the University of Limpopo, Biotechnology Unit laboratory. Metal concentrations in the muscle tissue were used to calculate hazard quotient for human health risk assessment which was based on the assumptions that an adult weighting 70 kg consume 150 g portion once per week. Alkaline pH was observed in the water throughout the study. Most water constituents were within the guidelines at both dams. The water at Flag Boshielo Dam was oligotrophic with Loskop Dam showing mesotrophic conditions. Concentrations were below detection level for most metals; however, significant concentrations were recorded in the bottom sediment. Although Loskop Dam is being described as a repository for pollutants from the upper Olifants catchment, no significant differences (p>0.05) were observed for metal concentrations in sediment between the two dams. Coinciding with sediment metal concentrations, liver, gills and muscle have shown notable concentrations for both species at Loskop and Flag Boshielo dams. The common trend of liver accumulating higher metal concentration followed by gill and muscle (liver>gills>muscle) was observed for most metals on O. mossambicus and L. rosae at both dams. In contrast, lead, strontium and manganese showed higher concentrations in the gills. Muscle exhibited lowest concentrations for most metals. Remarkable trends on the activities of biomarkers, lactate dehydrogenase (LDH), glucose-6-phosphate dehydrogenase (G6PDH), glutathione-S-transferase (GST) and acetylcholinesterase (AChE) were detected for both species at Loskop and Flag Boshielo dams. Labeo rosae population have shown a significantly high (p<0.05) LDH activities at Loskop Dam and no significant difference (p>0.05) was observed for Oreochromis mossambicus. Glucose-6-phosphate dehydrogenase activities exhibited no significant difference (p>0.05) for both species between the two dams. Labeo rosae have shown a significantly high (p<0.05) GST activities at Loskop Dam whereas Oreochromis mossambicus exhibited no significant difference (p>0.05) between the two dams. Acetylcholinesterase (AChE) has shown no significant difference (p>0.05) for both species between the Loskop and Flag Boshielo dams. LDH, G6PDH and GST activities have shown relationship with metal concentrations, which makes them good biomarkers of metal exposure.The condition factor indicated that overall conditions of O. mossambicus and L. rosae from Loskop and Flag Boshielo dams were good. Hepatosomatic index results were not conclusive. Most histopathological alterations were recorded on both species at both dams, but with different magnitude of severity. Regressive changes were more prominent in the liver and gills of both species at Loskop and Flag Boshielo dams followed by progressive change. Gills of Oreochromis mossambicus exhibited moderate modifications (score >20) at Loskop Dam and slight modification (score <20) at Flag Boshielo Dam. Labeo rosae populations have shown slight modifications (score <20) in the gills at both dams. Both species have shown significant difference (p<0.05) on the gill index between the two dams. Liver index has also exhibited significant difference (p<0.05) for each species between Loskop and Flag Boshielo dams. Slight modifications (score <20) were observed in the liver for both species at Loskop and Flag Boshielo dams. Both species have shown to accumulate metals within their tissues with liver accumulating higher concentration for most metals, followed by gills and muscle, respectively. Although muscle showed to accumulate lesser metal concentrations, it still raise a serious concern as it is the tissue consumed by human. Lead, chromium, cobalt and antimony concentrations have been the only metals of concern in this river system over the past few years; nevertheless, the present study has shown that other metals viz. arsenic, silver and selenium have exceeded international levels for safe consumption. Given the metal concentration trend reported over the past two decade in fish tissues, there is a need for urgent intervention to address the acid mine drainage problem to ensure sustainable development of the Olifants River and safety of communities depending on it for their livelihood. NRFand RAD

APA, Harvard, Vancouver, ISO, and other styles

8

van, der Walt Johannes Adriaan. "Black bass (Micropterus spp.) in the Olifants- Doorn River system: distribution, distribution barries, predatory impact and management." Thesis, Cape Peninsula University of Technology, 2014. http://hdl.handle.net/20.500.11838/856.

Full text

Abstract:

Thesis submitted in partial fulfilment of the requirements for the degree Master of Technology: Nature Conservation in the Faculty of Applied Sciences at the Cape Peninsula University of Technology In the Cape Floristic Region the Olifants- Doorn River (ODR) system is a known biodiversity hotspot in terms of endemic freshwater fish. Eight of the 10 described native freshwater fish species are endemic to this river system. One of the main threats to these fish is predation by introduced predatory fishes. Three species of alien invasive black bass (Micropterus salmoides, Micropterus dolomieu and Micropterus punctulatus) were introduced into the ODR system during the 1930s but prior to this study, their distribution and impacts had never been quantified on a system-wide basis. This study aimed to clarify the current distribution, distribution barriers, predatory impact and best management options for black bass in the ODR system. This was achieved by conducting a system-wide survey of 578 km of stream covering 41 tributaries in the ODR system. Black bass presence was tracked upstream within each tributary to its uppermost distribution point where physical barriers preventing further spread were identified and described. Fish species composition, abundance and size were recorded directly above and below these barriers to quantify black bass impact on the native fish. This research demonstrated that since introduction, natural and human assisted dispersal has facilitated not only the establishment of black bass in the Olifants and Doring main streams but also facilitated the invasions into 22 tributaries. Based on survey results it was estimated that 81.5 % of the ODR system that was previously occupied by native cyprinids is now invaded by black bass. Assessments of native fish abundance and size distribution above and below black bass invasion barriers demonstrated that in invaded tributaries only adults of larger cyprinids (Labeo seeberi, Labeobarbus capensis and Barbus serra) were able to co-occur with black bass species. Smaller fish such as juvenile L. seeberi, L. capensis and B. serra and native minnows (Barbus calidus, Pseudobarbus phlegethon and Barbus anoplus) were absent from the black bass invaded reaches. The findings of this catchment scale study are consistent with findings from other studies in the region. As a result, most native fishes are now restricted to streams above the natural barriers that limit the upstream invasions of black bass. Black bass eradication from invaded reaches is therefore necessary for habitat restoration. Effective eradication will however depend on the presence of barriers to prevent re-invasion from downstream sources. To better understand what constitutes the nature of such barriers, this study characterised the natural barriers that inhibited black bass invasions in 17 tributaries. Natural barriers comprised of 15 waterfalls, two cascades and one chute ranging in height from 0.49 m to 3.5 m with an average vertical drop of 1.21 ± 0.67 m. These findings suggest that black bass have poor jumping abilities and the recommended height of artificial barriers as part of a black bass management program should be between 80 and 100 cm depending on the size of the tributary. As a result, the presence of natural barriers or the construction of artificial barriers to prevent black bass invasions is considered a vital component of native fish conservation projects. Finally, the study assessed the feasibility of black bass eradication from the 22 invaded tributaries in the ODR system based on eight criterion covering aspects of biological, physical, anthropogenic and logistical importance. This assessment showed that effective eradication was most likely only feasible in seven tributaries. Prioritisation of these seven tributaries for black bass eradication based on the threatened status of the resident native species, the land-use in the respective catchments and the tributary length available for rehabilitation indicate that the Breekkrans, Biedouw and Thee Rivers should receive the highest priority.

APA, Harvard, Vancouver, ISO, and other styles

9

Oberholster, Petrus Fredrik. "Using the pollution-index method to assess water quality in the upper Olifants River Catchment, Mpumalanga Province." University of the Western Cape, 2017. http://hdl.handle.net/11394/6435.

Full text

Abstract:

Magister Scientiae - MSc (Environ & Water Science) The upper Olifants River catchment, situated in Mpumalanga Province, South Africa, is one of the main sources of water for this region. This region face challenges to guarantee future water security due to intensive land use activities e.g. mining, energy production, and agriculture activities. South Africa is the sixth largest producers of coal in the world and the Witbank (eMalahleni) coal fields, situated in the catchment, represents the largest conterminous area of active coal mining in South Africa. The second largest irrigation scheme (Loskop dam Irrigation Board) is also found below the Loskop Dam in the upper Olifants River catchment. The irrigation scheme of + - 480 km of irrigation channels provides water for a R1 Billion export industry of citric fruits to the European Union. Furthermore, the Olifants River in Mpumalanga is also a trans-boundary river that initially flows northwards before curving in an easterly direction through the Kruger National Park and into Mozambique where it joins the Limpopo River before discharging into the Indian Ocean. Although the Olifants River is one of the main river systems in South Africa, it has been described as one of the most polluted rivers in southern Africa, with Loskop Dam acting as a repository for pollutants from the upper catchment of the Olifants River system. Because Loskop Dam is of strategic important for the whole region the aim of the study was to show the implications of poor water quality on the local communities down stream of Loskop Dam that depend on water usage for their livelihood. (1) Developing a modified pollution index for the Loskop Dam, Mpumalanga Province using bioindicator algae species in relationship with water column physico-chemical parameters and national water guidelines as indication of pollution. (2) Analysing the threat of cyanobacteria, microsystin contaminations to crops irrigating by water from the Loskop Dam irrigation canals. (3) Discussing the social economic implication of water pollution on the Loskop Irrigation scheme and its stakeholders.

APA, Harvard, Vancouver, ISO, and other styles

10

Botha, Petrus Johannes. "The distribution, conservation status and blood biochemistry of Nile crocodiles in the Olifants river system, Mpumalanga, South Africa." Thesis, University of Pretoria, 2011. http://hdl.handle.net/2263/25717.

Full text

Abstract:

The outlook for Nile crocodiles in the Olifants River does not look optimistic. Since the increase in capacity of the Loskop and Flag Boshielo Dams, the crocodile population was left with no basking or nesting sites and has declined over the past 30 years. Shortly after the Massingire Dam in Moçambique filled to full capacity an estimated 160 crocodiles died in the Olifants River Gorge, a couple of kilometres upstream from the dam. The Olifants River is acknowledged by many experts as one of the most polluted rivers in South Africa and acid mine drainage, industrial pollution and untreated sewage in the river are all contributing to the poor water quality of the river. Further, the Department of Water Affairs and Forestry acknowledge that water demand already exceeds their capacity to supply and that the situation will worsen considerably in the near future. Aerial surveys of Nile crocodiles in the Olifants River was carried out during December 2005 and November 2009. An average total population of 714 Nile crocodiles were counted and corrected to an estimated 1140 individual crocodiles to eliminate the effects of undercounting. The Kruger National Park and specifically the area of the Olifants River Gorge was found to be one of the preferred habitat areas for crocodiles in the Olifants River as was the Flag Boshielo Dam, the area between the Blyde River and the western boundary of the Kruger National Park and the Olifants River between the Loskop Dam and the Flag Boshielo Dam. Repeated nesting in areas such as the Kruger National Park, the Flag Boshielo Dam and the Olifants River between the Loskop Dam and the Flag Boshielo Dam confirmed that these areas are critically important to the nesting success of Nile crocodiles in the Olifants River. The Elands River was confirmed as an important refuge area for Nile crocodiles in the Groblersdal-Flag Boshielo Dam area of the Olifants River. Surveys revealed an estimated total of only 15 crocodiles in the Loskop Dam and confirmed that no crocodiles in the large (2.1 - 4.0m TL) and very large size class (>4.0m TL) are currently present in the population. Blood biochemistry results indicate that the Olifants River Nile crocodile population probably suffers from chronic inflammation (especially in the Loskop Dam and Olifants River Gorge populations), infectious disease (particularly in the Loskop Dam population but all other sites also showed elevated values), possible inadequate diet and malnutrition (especially during the pansteatitis outbreak of August/September 2008) and are suffering serious immune problems in the Olifants River Gorge. A conservation and management plan is suggested which identifies threats to the continued existence of a viable Nile crocodile population in the Olifants River. Finally, it is suggested that the conservation status and risk of extinction of Nile crocodiles in the Olifants River be upgraded to the Endangered category since it currently complies to the following criteria; EN A2abce; C2a(i) published in the IUCN Red List Categories and Criteria Version 3.1 (IUCN, 2001). Thesis (PhD)--University of Pretoria, 2011. Centre for Wildlife Management unrestricted

APA, Harvard, Vancouver, ISO, and other styles

11

Bruwer, Rachel Jacoba. "The edaphic and climatic effects on production and wine quality of Cabernet Sauvignon in the Lower Olifants River region." Thesis, Stellenbosch : University of Stellenbosch, 2010. http://hdl.handle.net/10019.1/4342.

Full text

Abstract:

Thesis (MScAgric (Viticulture and Oenology))--University of Stellenbosch, 2010. ENGLISH ABSTRACT: Cabernet Sauvignon is the most planted red cultivar in South Africa and the second most planted red cultivar in the Olifants River region. The cultivar is prone to vigorous growth with low yields. Excessive irrigation could accentuate these cultivar characteristics. Considering the foregoing, the aim of the study was to describe how Cabernet Sauvignon will react to climate, soil type (texture) and irrigation within the Lower Olifants River wine region to enable growers to make the right decisions regarding long term as well as short term cultivation practices. This study is part of a project carried out by the ARC Infruitec-Nietvoorbij at Stellenbosch to determine the effects of soil type and atmospheric conditions on yield and wine quality of Cabernet Sauvignon in different grape growing regions of South Africa. Similar studies are being carried out in the Orange River, Stellenbosch and Swartland regions of South Africa. The Lower Olifants River region could be divided into three climatic regions. Furthermore, two climatic regions is evident regarding the formation of grape wine colour and aromas. Proximity to the Atlantic Ocean would play an important role in a cultivar establishment policy. The variation in stem water potential (ΨS) could be related to soil water status expressed in terms of matric potential (ΨM). In the case of sandy soils, ΨS decreased substantially more as the ΨM decreased compared to the sandy loam soils. The reason could be that the unsaturated hydraulic conductivity in sandy soils decreased more rapidly as the ΨM decreased compared to the heavier soils. Thus could explain why the grapevines in the sandy soils experienced more water stress than the ones in the sandy loam soils at a given ΨM. Climate had a strong influence on grapevine water status with grapevines nearer to the ocean experiencing less water stress compared to the ones further inland. This was especially true for grapevines in the sandy soils. Vegetative growth and yield of grapevines in the sandy soils were more sensitive to water deficits compared to the ones in the sandy loam soils. For deficit irrigated grapevines in the sandy soils, vegetative growth and yield decreased by ca. 30% when ca. 55% less water was applied from flowering to harvest. Yield reduction were ca. 15% with no or very little influence on vegetative growth with ca. 80% reduction in water applied from flowering to harvest for grapevines in the sandy loam soils. The influence of soil texture on wine quality and style were evident under intensive irrigation as well as over different climatic regions. Overall sensorial potential wine quality of grapevines in sandy soils tended to be higher compared to the ones in the sandy loam soils. Deficit irrigation tended to increase wine colour intensity, irrespective of soil texture. Furthermore, deficit irrigation in sandy loam soils tended to increase wine fullness and the berry characteristics of the wine. Berry characteristics of wines from the sandy soils tended to be higher compared to the ones from the sandy loam soils. Too severe water deficits in sandy soils could be detrimental to wine quality. Climate tended to have an influence on wine style of grapevines in the sandy soils with wines produced further away from the ocean tended to have higher berry characteristics. Irrigation management could be a powerful tool to manipulate the grapevine in sandy soils. For grapevines the sandy loam soils in addition to regulated deficit irrigation, additional canopy management practices could be needed to improve wine quality. AFRIKAANSE OPSOMMING: Cabernet Sauvignon is die mees aangeplante rooidruif kultivar in die Suid-Afrikaanse wynbedryf. In die Olifantsriver streek is dit naas Shiraz, die tweede mees aangeplante rooidruif kultivar. Cabernet Sauvignon is bekend as ‘n groeikragtige skaamdraer. Indien oorbesproei word, kan hierdie potensiële nadelige eienskappe nog meer na vore tree. Die doel van die studie is om die invloed van die klimaat, grond en besproeiing op Cabernet Sauvignon se vegetatiewe groei, produksie en wyngehalte in die Benede Olifantsrivier streek te bepaal. Hierdie inligting kan produsente help om ingeligte kortsowel as langtermyn besluite te maak rakende die verbouing van Cabernet Sauvignon. Hierdie studie vorm deel van ‘n breër studie in die Suid-Afrikaanse wynbedryf, gedryf deur die Landbou Navorsingsraad (LNR) Infruitec-Nietvoorbij, Stellenbosch om die invloed van atmosferiese toestande en grond op die produksie en wyngehalte van Cabernet Sauvignon te bepaal. Soortgelyke projekte word uitgevoer in die Oranjerivier, Stellenbosch en Swartland wynstreke. Die Benede Olifantsrivier streek kan verdeel word in drie klimaatstreke op grond van temperatuurdata. In terme van die ontwikkeling van druifkleur en aromas, kan die streek verdeel word in twee klimaatstreke. Die afstand vanaf die Atlantiese Oseaan kan ‘n belangrike rol speel in die ontwikkeling van ‘n kultivarriglynplan vir die streek. Grondwaterstatus, uitgedruk as die matrikspotensiaal (ΨM), kan aanleiding gee tot variasie in middag blaarwaterpotensiaal (ΨS) lesings. Die ΨS van die sand gronde verlaag vinniger soos die ΨM verlaag invergelyke met die sandleem gronde. Dit kan moontlik wees as gevolg van die verskil in die grond onversadigde hidroliese konduktiwiteit. Sand gronde se hidroliese konduktiwiteit verlaag vinniger soos die ΨM verlaag, invergelyke met sandleem gronde. Dit verklaar waarom wingerde in sand gronde by dieselfde ΨM, meer waterspanning ondervind as wingerde in sandleem gronde. Klimaat het ‘n invloed op die waterstatus van die wingerdstok. Wingerde nader aan die see het minder waterspanning ondervind invergelyke met wingerde wat verder in die binneland geleë is. Dit was veral die geval met wingerde in die sand gronde. Vegetatiewe groei en produksie van wingerde in die sand gronde is meer sensitief vir waterspanning as wingerde in die sandleem gronde. Tekortbesproeiing in die sand gronde het die groei asook produksie met ongeveer 30% verlaag deur ongeveer 55% minder water toe te dien vanaf blom tot oes. In teenstelling daarmee is die produksie van wingerde in die sandleem gronde met ongeveer 15% verlaag met geen tot baie min verlaging in die groeikrag. Ongeveer 80% minder water is toegedien vanaf blom tot oes. Grondtekstuur kan wyngehalte en -styl beïnvloed ten spyte van intensiewe besproeiing en klimaatsverskille. Sensoriese potensiële wyngehalte van wingerde in die sand gronde was beter invergelyke met dié van die sandleem gronde. Die wyne vanaf die sand gronde het ook geneig om oor meer bessie intensiteit te beskik as wyne vanaf die sandleem gronde. Tekortbesproeiing neig om die wynkleur intensiteit te verhoog, ongeag van grondtekstuur. Tekortbesproeiing in die sandleem gronde kan ook die volheid van die wyne verbeter, asook die bessie intensiteit van die wyn verhoog. Te hoë waterspanning in die sand gronde kan wyngehalte nadelig beïnvloed. Klimaat kan ook die wynstyl vanaf sand gronde beïnvloed met wyne verder vanaf die see wat oor meer bessie intensiteit beskik as wyne nader aan die see. Beheerde tekortbesproeiing kan as ‘n kragtige hulpmiddel gebruik word om wingerde in die sand gronde te manipuleer. Vir wingerde in die sandleem gronde, addisioneel tot beheerde tekortbesproeiing en normale loofbestuurspraktyke, kan ekstra loofbestuurspraktyke bv. die verwydering van sylootlote, dalk nodig wees om wyngehalte te verbeter.

APA, Harvard, Vancouver, ISO, and other styles

12

Brand, Desireé. "The co-design of a visual arts-based intervention within the community of the Olifants River valley in South Africa." Thesis, Cape Peninsula University of Technology, 2016. http://hdl.handle.net/20.500.11838/2438.

Full text

Abstract:

Thesis (MTech (Design)--Cape Peninsula University of Technology, 2016. The research was motivated by my lived experience in the Olifants River community of Namaqualand. In this community there are many diverse ethnic and social groupings with considerable potential to contribute to indigenous knowledge and creative practices. These groupings are, however, fragmented, with no platform for their varied and rich cultural assets to be displayed and acknowledged. In addition, the research was motivated by the call for a platform for the arts in the region. It is argued that visual art practice is an instrumental tool in the advancement of both creativity and social cohesion in this community. The research commenced with a pilot study, comprising workshops, which were run by art practitioners from various sectors in the region. Primary literature that influenced the emerging research design was that of Solomon (2007) as well as the holistic cultural viewpoints of Schafer (2014). The organic process of qualitative research methods as described by Ellingson (2009) was a natural personal directive. Body mapping was used during a preparatory phase that led to the creative exploration of community members’ own identity. Storytelling and dance were included in the design methodology since they enabled a psychosocial process of validating art practice as an economic asset within the community as well as enhancing social cohesion in the community. Crystallisation methods implemented in the process-driven body map workshops were held for grassroots -, town – and township sectors in the Olifants River valley. Each of the workshops comprised ten participants who were invited to participate in a subsequent do-designed collaborative event.

APA, Harvard, Vancouver, ISO, and other styles

13

Brand, Desiree. "The co-design of a visual arts-based intervention within the community of the Olifants River valley in South Africa." Thesis, Cape Peninsula University of Technology, 2016. http://hdl.handle.net/20.500.11838/2509.

Full text

Abstract:

Thesis (MTech (Design)--Cape Peninsula University of Technology, 2016. The research was motivated by my lived experience in the Olifants River community of Namaqualand. In this community there are many diverse ethnic and social groupings with considerable potential to contribute to indigenous knowledge and creative practices. These groupings are, however, fragmented, with no platform for their varied and rich cultural assets to be displayed and acknowledged. In addition, the research was motivated by the call for a platform for the arts in the region. It is argued that visual art practice is an instrumental tool in the advancement of both creativity and social cohesion in this community. The research commenced with a pilot study, comprising workshops, which were run by art practitioners from various sectors in the region. Primary literature that influenced the emerging research design was that of Solomon (2007) as well as the holistic cultural viewpoints of Schafer (2014). The organic process of qualitative research methods as described by Ellingson (2009) was a natural personal directive. Body mapping was used during a preparatory phase that led to the creative exploration of community members’ own identity. Storytelling and dance were included in the design methodology since they enabled a psychosocial process of validating art practice as an economic asset within the community as well as enhancing social cohesion in the community. Crystallisation methods implemented in the process-driven body map workshops were held for grassroots -, town – and township sectors in the Olifants River valley. Each of the workshops comprised ten participants who were invited to participate in a subsequent do-designed collaborative event.

APA, Harvard, Vancouver, ISO, and other styles

14

Soderberg, Keir. "Geochemistry of the fynbos ecosystem in a Table Mountain Group sub catchment of the Olifants River, Western Cape, South Africa." Master's thesis, University of Cape Town, 2003. http://hdl.handle.net/11427/4225.

Full text

Abstract:

Bibliography: leaves 104-118. This study gives a first-order estimation of the chemical composition of the recharge, discharge, and ground waters, along with the bedrock, soil, and vegetation of the Olifants River Valley around Citrusdal. The valley occurs in a synclinal fold with the main aquifers, the Table Mountain Group (MG) sandstones of the Peninsula Formation and the Nardouw Subgroup, folded beneath the central valley.

APA, Harvard, Vancouver, ISO, and other styles

15

Mahlatji, Matlale Letticia. "The impact of water and sediment quality on the health of clarias gariepinus (burchell, 1822) and labeo rosae (steindachner, 1894) at the Phalaborwa Barrage, Olifants River, Limpopo Province." Thesis, University of Limpopo (Turfloop Campus), 2014. http://hdl.handle.net/10386/1152.

Full text

Abstract:

Thesis (M.Sc. (Zoology)) --University of Limpopo, 2014 Contamination of aquatic ecosystems by agricultural and mining activities, as well as by industrial discharges and urbanization in the catchment of the South African river systems has been the cause of increasing public concern. These activities may result in water pollution. One such river is the Olifants River System in Mpumalanga and Limpopo provinces which is highly impacted. The main aim of the study was to assess the impact of the water and sediment quality on the health of Clarias gariepinus and Labeo rosae and human risk when the fish is consumed at the Phalaborwa Barrage in the Lower Olifants River, Limpopo Province. This was achieved by assessing the water and sediment quality of the barrage at the three sampling sites; assessing the condition of the fish and the fish parasites by applying the fish HAI (Health Assessment Index) and PI (Parasite Index); determining the bioaccumulation of selected metals in the muscle tissue of the two fish species; and to determine the Human health risk factor upon consumption of fish contaminated with metals at the barrage. Ten fish from each fish species were collected seasonally at each site using gill nets of different mesh sizes. Standards methods were followed when testing selected water and sediment constituents. For water quality sampling, the water samples were collected over four seasons (autumn, winter, spring and summer) at three sites (inflow, wall and below wall) from April 2010 to January 2011. Sediment samples were also collected using a Friedlinger mudgrab (225cm3) at the three sites during winter and summer. Fish hosts were examined for mobile ectoparasites, weighed and measured. Blood samples were drawn and skin smears were made. Fish were killed, dissected and all external and internal organs were examined as prescribed in the fish health assessment index. The condition factor was determined for each fish population. All parasites were collected, fixed and preserved using standard methods. The highest water temperature (28.5 ºC) was in spring and lowest in winter (18 ºC). Overall pH was in an alkaline condition as it ranged from 7.4 to 8.7. Most water quality parameters were recorded at higher concentration in spring which includes; water temperature, pH, conductivity, salinity, TDS, alkalinity, and turbidity. Major ions (cations and anions) recorded were all within the TWQR. Sulphates concentrations were all within the TWQR. Calcium concentration levels exceeded the typical concentration limit in spring but the levels were still within the TWQR for domestic use. Nutrients levels (nitrate, nitrite, sulphate) were very low which indicate oligotrophic conditions. Highest total nitrogen was recorded in spring which is an indicative of eutrophic conditions. Highest phosphorous concentrations were recorded in winter, spring and summer which are an indicative of eutrophic conditions. Noticeable elevated levels were recorded at the inflow in summer which is an indicative of hypertrophic conditions. The results of the metals concentrations analysed demonstrated that metals within the barrage are present in trace amounts in the water. Analysis of the metal concentrations in water, sediment and fish muscle tissue revealed that the sediment contained the highest concentrations of metals followed by fish tissue and then the water. Metals that were detected in the water column includes; aluminium, antimony, arsenic, barium, boron, iron, manganese, selenium, strontium and tin. Metals that were detected at concentrations above the TWQR for aquatic ecosystem were; aluminium, antimony and selenium. Arsenic, cadmium and chromium were recorded at concentrations above the detection limit as suggested by CCME. Zinc concentrations were recorded at levels below suggested detection limit. Aluminium, barium, boron, cadmium, chromium, manganese, selenium and strontium were all detected at elevated levels in water and above the TWQR. Among the metals recorded in the water column, significant seasonal variations in concentration were found for aluminium, barium, boron, lead selenium and strontium whereas only boron showed a significant variation between sites. In comparison to the metals concentrations accumulated in the muscle tissue of both fish species. It was noted that C.gariepinus accumulated more metals than L. rosae; however L. rosae accumulated more metals at elevated concentrations than C. gariepinus. The metals that were accumulated at elevated levels in C. gariepinus were barium, boron, zinc and selenium. In L. rosae, iron, aluminium, strontium, titanium, vanadium and arsenic accumulated at elevated levels. All these metals pose a high risk to fish and human’s health. The highest population HAI was recorded in summer for both fish species. The lowest HAI value was recorded in autumn for both fish species. Although a high HAI population value was recorded higher in summer for both fish species, in general both fish species from the barrage were in a normal condition. A high number of ectoparasites were recorded in L. rosae than in C. gariepinus while high numbers of endoparasites were recorded in C. gariepinus than L. rosae. The dominating ectoparasites for both species were from the class monogenea. Although the prevalence for Contracaecum sp. in C. gariepinus was 100% in all season, it did not influence the condition of the host. None of the parasites identified from both fish species neither reached alarmingly infection levels nor caused any visible damage to the host. In conclusion, the water quality at the Phalaborwa Barrage is slightly polluted based on the water quality parameter(phosphorous) presence and recorded of some metals at the inflow that were recorded at elevated levels above the TWQR. Further recommendations are refereed such as extension of this study to all tributaries and to include other fish species in addition to constant monitoring of the impoundment.

APA, Harvard, Vancouver, ISO, and other styles

16

Onjira, Phoebe Pauline Ingado [Verfasser], and F. [Akademischer Betreuer] Nestmann. "Influence of Morphology, Climate Change and Landuse Change on Water Partitioning in Olifants River Basin / Phoebe Pauline Ingado Onjira ; Betreuer: F. Nestmann." Karlsruhe : KIT-Bibliothek, 2020. http://d-nb.info/121957788X/34.

Full text

APA, Harvard, Vancouver, ISO, and other styles

17

Onjira, Phoebe Pauline [Verfasser], and F. [Akademischer Betreuer] Nestmann. "Influence of Morphology, Climate Change and Landuse Change on Water Partitioning in Olifants River Basin / Phoebe Pauline Ingado Onjira ; Betreuer: F. Nestmann." Karlsruhe : KIT-Bibliothek, 2020. http://d-nb.info/121957788X/34.

Full text

APA, Harvard, Vancouver, ISO, and other styles

18

Gohell, Ashla Fiona. "The impact of water and sediment quality on the health of Oreochromis Mossambicus (Peters, 1852) and Schilbe Intermedius Ruppell, 1832 at the Phalaborwa Barrage in the Olifants River." Thesis, University of Limpopo, 2014. http://hdl.handle.net/10386/1225.

Full text

Abstract:

Thesis (MSc. (Zoology)) -- University of Limpopo, 2014 The Olifants River is presently one of the most threatened river systems in South Africa. The Upper and Middle catchments are heavily impacted by anthropogenic activities, however little is known of the status of the river in the Lower catchment in the Limpopo Province. Thus the aim of this study was to evaluate the impact of water quality on the health of Oreochromis mossambicus and Schilbe intermedius at the Phalaborwa Barrage. This was achieved through assessing the water (seasonally) and sediment quality (bi-annually) at three sites in the Phalaborwa Barrage (inflow, middle and the wall). Ten specimens of each of the two selected fish species were seasonally collected using gill nets of different mesh sizes from May 2010 to January 2011. The water, sediment and the dorsal muscle tissues from both fish species were analysed for selected metals at an accredited laboratory by means of ICP-OES spectrometry and the human health risk factor upon consumption of fish contaminated with metals was assessed. Fish health was determined at the field laboratory by applying the HAI, PI and IPI. In addition, the condition factor (CF) was determined for the selected fish species during all seasons. All water constituents with the exception of turbidity during spring (wall), anions (Cl, F and SO4) and cations (Ca, K, Mg and Na) fell within the target water quality range (TWQR) for aquatic ecosystems throughout the study. Inorganic nitrogen concentrations showed eutrophic (spring) and oligotrophic conditions (autumn, winter and summer), while phosphorus indicated eutrophic (autumn, winter and spring) and hypertrophic (summer) conditions throughout the study. There was no significant difference in anions (F=0.07; df=3; p=0.97), cations (F=0.57; df=3; p=0.64) and nutrients (F=0.79; df=3; p=0.56) detected in water. The metals that were detectable in the water samples were: Al, Fe, Sn, B, Sr, Se, Ba, Mn, Sb and As, while in sediment all metals (Fe, Al, Ti, Mn, Ba, B, Zn, Ag, V, Cr, Ni, Sr, Sn, Co, Cu, Cd, Pb, As and Sb) were detected with the exception of Se. The average metal concentrations detected above the TWQR are; Al, Fe, Se, Sn, Sb and As, in the sediment only Cr and Cd were above suggested quality guidelines. There was no significant difference in metals detected in water (F=0.05; i df=3; p=0.98) and sediment (F=1.62; df=1; p=0.21). Higher HAI values were recorded for S. intermedius than O. mossambicus, indicating that O. mossambicus was in better health than S. intermedius. For S. intermedius, parasites contributed the most to the total HAI followed by abnormal liver conditions, haematocrit levels (internal variables) and abnormal gills (external variable). While for O. mossambicus, parasites, liver, haematocrit (internal variables), gills, eyes, fins and skin (external variables) contributed to the HAI values. There was no significant difference in HAI values for O. mossambicus (F=1.9; df=3; p=0.15) and S. intermedius (F=2.58; df=3; p=0.66) throughout the study. The PI and IPI for ectoparasites for both fish species, were higher than the PI for endoparasites. There was a significant difference for PI values of O. mossambicus (F=0.07; df=3; p=0.041) and S. intermedius (F=3.65; df=3; p=0.019) during the study. Oreochromis mossambicus had higher CF values than S. intermedius and both fish species had values that indicated good fish. Metals that were detectable in O. mossambicus muscle tissue included: Ba, B, Zn, Fe, Sr, Al, Mn, Cr, Ag, Pb, Ni, Cu, Se, V, Sb, Ti, Sn and Co, while for S. intermedius Ba, B, Zn, Fe, Al, Cr, Sr, Mn, Cu, As, Pb, Se, Sn, Ag, Ti, Ni, Sb and Co were recorded. There was no significant difference in bioaccumulation levels between the two fish species (F=1.412; df=3; p=0.250). The human health risk assessment indicated that fish muscle tissues are unsuitable for continuous (weekly/daily) consumption. As some carcinogenic metals i.e. Pb, Cr and Sb for O. mossambicus and Pb, As and Cr for S. intermedius were detected at HQ levels of more than 50 times the recommended value of one. In conclusion, the Phalaborwa Barrage is impacted by metals (Al, Fe, Se, Sn, Sb and As) and occasionally with nutrients. The water and sediment quality and metal bioaccumulation have confirmed the latter statement and to a lesser extent the HAI, PI and IPI. The human risk assessment done indicated that continuous consumption of fish by humans, especially O. mossambicus may have adverse effects on the health of humans.

APA, Harvard, Vancouver, ISO, and other styles

19

Ramalepe, Tshepiso Promise. "Effects of pollution and metazoan parasites on the health and oxidative stress biomarkers of two cyprinid fish species in the Olifants River System, South Afrrica." Thesis, University of Limpopo, 2015. http://hdl.handle.net/10386/1525.

Full text

Abstract:

Thesis (M. Sc. (Zoology)) -- University of Limpopo, 2015 The unprecedented expansion in human population and industry, since the industrial revolution in the late 1700s, has led to increased anthropogenic activities which have indisputably impacted freshwater ecosystems and biological communities therein, including fish. Although this has understandably been the focus, under natural aquatic conditions, no organism is only affected by pollution. Parasites have also been shown in a number of interdisciplinary studies to affect the health of aquatic hosts (amphibians, crustaceans, fish, and mammals). This is illustrated in a number of comprehensive studies the detrimental effects parasites exacerbate when their hosts (fish) are stressed. Therefore, the ability of parasites to interact with anthropogenic stressors, as well as effects they have on the genetic, cellular or tissue level of their host is crucial in conservation and sustaining aquatic biodiversity. As such, the present study examined the combined effects of pollution and metazoan parasites on the health and oxidative stress biomarkers, evaluated for the first time for silver carp, Hypophthalmichthys molitrix (Valenciennes, 1844) and rednose mudfish, Labeo rosae Steindachner, 1894, in one of South Africa’s impacted freshwater ecosystems, Flag Boshielo Dam, Olifants River System, Limpopo Province. Seasonal surveys were conducted from February 2012–January 2013. A total of 111 H. molitrix and 116 L. rosae fish specimens were collected using conventional angling gear, scoop and gill nets with stretched mesh sizes of 30–110 mm. The two selected cyprinid fish species were assessed for oxidative stress biomarkers [Glutathione S-transferase (GST), lipid peroxidation (MDA) and Total Antioxidant Capacity (TAC)] and parasitism of metazoan parasites. Concentrations of biomarkers of oxidative damage and antioxidant defense in the gill and liver tissue were measured to assess how these major organs of the immune system responded to oxidative stress associated with parasitic infections. In addition, water quality analyses were carried out by testing an assay of physico-chemical parameters to establish the level of contamination. Fish health was assessed using the Health Assessment Index (HAI), refined Parasite Index (PI), Inverted Parasite Index (IPI) and Condition Factor (K) protocols. Relative to previous studies at Flag Boshielo Dam, water quality results showed an increase of nutrients, major ions and several metals which may have adverse effects that may comprise fish health; however, this dam remains moderately polluted in a mesotrophic state. The fish health assessment results indicated that H. molitrix was more affected in terms of the necropsy and parasite based assessments (HAI, IPI and K) with mean±SD of 65.68±35.51; 68.29±25; 0.82±0.20, respectively, as compared to 39.14±22.44; 28.79±18.33; 1.17±0.21 for L. rosae during the study. In addition, significantly higher parasitic infections (mean prevalence of infection with any species of parasite = 45.3±0.13) were observed for H. molitrix than L. rosae (12.0±0.05). Furthermore, there was considerable variation in biomarker concentration between highly infected and non-infected fish, for and between each species and tissues with regard to parasite infection, suggesting that the specific functions of each tissue are associated with their susceptibility to oxidative stress, as well as their ability to defend against oxidative damage. These results illustrate that although fish are affected by aquatic contaminants they are to an extent affected by parasites, which may act synergistically on the health of the two fish species. Most importantly, it was suggested that knowledge on the parasites of alien H. molitrix when compared to indigenous L. rosae may give an indication of how adaptive this fish are to new localities as well as expands the information on the rarely studied biology, epizootiology and ecological interactions of these two cyprinid species. Keywords: Health Assessment Index, refined Parasite Index, Inverted Parasite Index, Condition Factor, water quality, lipid peroxidation, Glutathione S-transferase, Total Antioxidant Capacity, Hypophthalmichthys molitrix, Labeo rosae, Flag Boshielo Dam.

APA, Harvard, Vancouver, ISO, and other styles

20

Mogashoa, M. E. "Seasonal variation in haematological parameters and oxidative stress bio-markers for selected fish species collected from the Flag Boshielo Dam, Olifants River System, Limpopo Province, South Africa." Thesis, University of Limpopo, 2015. http://hdl.handle.net/10386/1188.

Full text

Abstract:

Thesis (M.Sc. (Physiology)) --University of Limpopo, 2015 Water is an essential and yet scarce resource, which has a vital role for human use and also serve as a habitat for numerous organisms in aquatic environments. Despite its scarcity there have been many reports indicating that it is continually polluted by domestic, agricultural, mining and other anthropogenic activities; subsequently affecting the health of organisms residing in such water bodies. Fish have been selected as the bio-monitoring species due to its direct interaction with the environment; thereby making it an appropriate model to monitor and evaluate the health status of the environment. The feral population of the alien species, Hypopthalmichtys molitrix (Valenciennes, 1844) commonly known as the silver carp in Flag Boshielo Dam has been considered a healthy population. However, this perception changed considerably after reports of lethargic, dying fish were first noted in 2011. Currently the sporadic deaths amongst mature specimens (>0.7m) persist; and the reason(s) for their demise remains unclear. Therefore, the aim was to employ a seasonal study design to investigate the health status of selected fish species such as H. molitrix in Flag Boshielo Dam by evaluating haematological parameters, oxidative stress biomarkers and bio-accumulation levels of particular transition metals. Seasonal surveys were carried out from February 2012 to January 2013 at Flag Boshielo Dam, Olifants River System, Limpopo Province. The locality surrounding the dam is known to be in an agriculture and mining catchment. Hypopthalmichtys molitrix and Labeo rosae (Steindachner, 1894) commonly known as the rednose labeo were collected with the use of scoop nets, conventional angling gear and gill nets. Following collection, morphometric measurements were taken and blood was collected. The blood samples required for further analysis at the Medical Science Department, University of Limpopo were kept on ice (4˚C). After the collection of all blood samples the specific fish was sacrificed and muscle samples were collected for bio-accumulation analysis and gills and liver samples were collected for the measurement of oxidative stress biomarkers. These tissue samples were rapidly frozen and kept frozen (-85˚C) until further analysis. Haematological parameters from the study reflected a variation amongst comparison of the inter- and intra-species. It was observed that mature H. molitrix suffered from anaemia. The response of glutathione-S-transferase (GST) and thiobarbituric acid reactive substances (TBARS) was relatively constant throughout all seasons when the young (<0.5m) and mature H. molitrix (0.6 – 0.90m) specimens were compared. However, the catalase (CAT) response of mature H. molitrix was dramatically impaired. This would increase their vulnerability to oxidative stress. Bioaccumulation levels of the eleven selected transition elements exhibited various trends. Metals such as Molybdenum (Mo), Vanadium (V), (Chromium) Cr, Cobalt (Co), Zinc (Zn), Cadmium (Cd) and Mercury (Hg) exhibited seasonal bio-accumulation levels that were in support of the various feeding behaviours of the fish species in this study. On the other hand, metals such as Manganese (Mn), Iron (Fe), Copper (Cu), Zinc (Zn), Cadmium (Cd) and Mercury (Hg) also illustrated the potential to be contributing factors in the death of the mature specimens. In conclusion, the findings from this study illustrate the complex nature of metabolic disturbances resulting in the death of mature H. molitrix specimens. It is clear that no single aspect investigated in this study could be solely implicated as the major cause of death. This multifactorial presentation necessitates further haematological assessment focussing on blood cell morphology and pathology, as well as investigations into other oxidative stress biomarkers in liver and gill tissue. In addition, identifying the most appropriate tissue type for future bio-accumulation measurements of transition metals in this feral population is necessitated. It is further suggested that neuro-muscular assessments, focussing on neurotransmitters such as γ-aminobutyric acid (GABA) and acetylcholine (Ach), form part of the investigation into the lethargic behaviour of the mature fish.

APA, Harvard, Vancouver, ISO, and other styles

21

Kekana, Milicent Barileng. "The impact of water and sediment quality on the health of schilbe intermedius r"uppel, 1832 and labeo rosae steindachner, 1984 at Flag Boshielo Dam, Olifants River System, Limpopo Province." Thesis, University of Limpopo (Turfloop Campus), 2013. http://hdl.handle.net/10386/1001.

Full text

Abstract:

Thesis (M.Sc. (Zoology)) --University Limpopo, 2013 Major anthropogenic activities such as, mining, coal-fired power stations and intensive agricultural practices in the upper catchment area of the Olifants River, have a dramatic impact on the water quality downstream. As a result the river is presently the third most polluted river in South Africa. The aim of this study was to assess the impact of water and sediment quality on the health of Labeo rosae and Schilbe intermedius. The aim was accomplished by applying the Fish Health Assessment Index (HAI) which includes the Parasite Index (PI) at Flag Boshielo Dam in the Middle Olifants River, Limpopo Province. This was achieved through; assessing the water quality of the dam by determining the levels of physical and chemical constituents in the water at three sampling sites, determining the bioaccumulation of selected metals in the muscle tissue of the two fish species, assessing the fish health (including the fish condition factor) and the fish parasites in the dam by using the fish HAI and PI, and ascertaining the Human Health risk factor upon consumption of fish contaminated with metals from the dam. The water and sediment quality were seasonally sampled at three sites in the dam: inflow, middle and wall. Dorsal muscle tissues from both fish species were collected for metal bioaccumulation analyses. The water, sediment and fish muscle tissue samples were analysed by an accredited laboratory by means of ICP-OES spectrometry. For the fish health and parasites, ten fish per species were collected seasonally (July 2009 to April 2010) by means of gill nets and examined at a field laboratory using the HAI and PI protocol. Generally the water quality of Flag Boshielo Dam was acceptable for aquatic ecosystems according to the SAWQG with the exception of phosphorus and some metals at the inflow area. The pH ranged between slightly acidic to alkaline values; water temperature: 15°C to 26°C; water hardness medium soft, salinity within the freshwater range; turbidity in the clear water range. The TDS and major ions (salts) were acceptable for the duration of the study. The highest concentrations of nutrients (specifically phosphorus) as well as metals (aluminium, cadmium, copper, iron and lead) were recorded at the inflow area of the dam. The nutrients were very low except the eutrophic range phosphorus concentrations recorded at the inflow whereby, the Elands River may be an additional source of nutrients into Flag Boshielo Dam. The metals that were recorded above TWQR are; aluminium, cadmium, copper, iron and lead, of which were mostly recorded at the inflow. However, statistically there was no significant difference among the three sampling sites. The metal concentrations at the inflow were recorded only slightly higher than the middle and the dam wall. The main source of the metals may be the water coming from catchment area of the dam given the intensive agricultural activities taking place between Loskop Dam and Flag Boshielo Dam. Sediment and bioaccumulation: All the metals were recorded at higher concentrations in the sediment than in the water and fish muscle tissue, except antimony, selenium and strontium. The most abundant metals recorded in the sediment were iron and aluminium. However, the concentrations above the TEL were cadmium, nickel and zinc. The elevated metal concentrations in the sediment are indicating that the metal load in the sediment of Flag Boshielo Dam could be a potential risk for the aquatic biota if they become bioavailable. Antimony, selenium and strontium metal concentrations were recorded at higher concentrations in the muscle tissue of both fish species than in the sediment and water. Iron was the most accumulated metal in the muscle tissue of both fish species. In terms of numbers, more metals were recorded in the muscle tissue of S. intermedius than in L. rosae however the metal concentrations were higher in the latter. This can be attributed to their different trophic levels in the food chain; L. rosae is a primary consumer while S. intermedius is a tertiary consumer. However, the metals that accumulated in the fish muscle tissue were indicative of bio-availability of the toxic metals in the dam and not water/sediment pollution. According to a Human Health risk assessment (Chapter 3), metals that may have risks upon consumption of L. rosae are; antimony, arsenic, chromium, iron and vanadium; for S. intermedius are; antimony, chromium, iron, vanadium and arsenic (in descending order). These metals may pose toxic and carcinogenic risks to humans. Therefore, the rednose labeo (L. rosae) and to a lesser extend the silver catfish (S. intermedius) fish species from Flag Boshielo Dam may not be suitable for humans if consumed above 350 g per week. Fish health and parasites: The Health Assessment Index (HAI) values of the two fish species differed significantly with higher index values recorded for S. intermedius than L. rosae. Besides the Parasite Index (PI), abnormal haematocrit readings, liver conditions, skin lesions and clubbed gills are the necropsy anomalies that contributed predominantly to the HAI. Overall, the PI contributed mostly to the total HAI value. The parasite load and therefore also the mean intensity, mean abundance and prevalence of S. intermedius were higher during all seasons than that of L. rosae. The dominant ectoparasites for both species were from the Class Monogenea and the dominant endoparasites were nematodes. Out of 40 L. rosae sampled, 139 parasites were retrieved; five parasite species were ectoparasites and two endoparasites. From the 40 S. intermedius sampled, 2473 parasites were retrieved, from which two species (one genus) were ectoparasites and three species were endoparasites. The condition factor is used to compare the “condition”, “fatness” or wellbeing of fish and it is based on the hypothesis that heavier fish of a particular length are in a better physiological condition. The L. rosae had a better condition factor, recorded at values less than (2) as compared to S. intermedius (>2). The cause of the HAI necropsy anomalies may have been also from parasite load other than the metals in the water and sediment. However, the HAI alone cannot be used for metal pollution, unless it is done in conjunction with a histopathological study of the tissues/organs. Therefore, the cause of the recorded anomalies from both fish species is inconclusive. On the hand, fish can be used as bioindicators because the accumulated metals in the fish tissues are indicative of the bioavailability of metals in Flag Boshielo Dam.

APA, Harvard, Vancouver, ISO, and other styles

22

Booyens, Paul Lodewyk. "Pollutants associated with mass mortality of Nile crocodiles (Crocodylus niloticus) in the Kruger National Park, South Africa / P.L. Booyens." Thesis, North-West University, 2011. http://hdl.handle.net/10394/5564.

Full text

Abstract:

The first of a series of mass mortalities of Nile crocodiles in the Olifants and Letaba rivers in the Kruger National Park (KNP) was reported in the winter of 2008. The present study investigated the levels and possible effects on eggshell thickness of inorganic elements and organic pollutants in Nile crocodile eggs from these rivers, and comparing them with eggs from a reference crocodile farm and a reference dam inside the KNP. The egg contents were analyzed for chlorinated organic compounds and brominated flame retardants. Eggshells and egg contents were analyzed for inorganic elements. The elemental concentrations in the eggshells and contents were low when compared with previous studies. The highest concentrations were found in the eggs from the reference crocodile farm. The eggs from the reference dam and the crocodile farm had thicker shells, and the eggs from the Olifants and Letaba rivers had thinner shells. Not all eggs in a female develop at the same rate, while eggshell formation presumably occurs at the same time for all eggs. As a result, the elemental profile of egg contents may differ between eggs of the same clutch, but less so for the shells. Weak or no associations were found between the elemental concentrations of the content and eggshells and eggshell thinning. A possible organic pollutant–induced eggshell thinning effect was found. The compounds found were not at levels that could have caused the mortalities, but may affect the sex ratios through endocrine disruption. Further studies are therefore required. Thesis (M.Sc (Environmental Science))--North-West University, Potchefstroom Campus, 2011.

APA, Harvard, Vancouver, ISO, and other styles

23

Watson, Raylene Mullineux. "Metal bioaccumulation in Clarias gariepinus in the Olifants River catchment area." Thesis, 2012. http://hdl.handle.net/10210/7723.

Full text

Abstract:

M.Sc. A comparative study was undertaken in the Olifants River catchment, to determine the water quality at two dam sites, namely, Bronkhorstspruit Dam (control) and Loskop Dam (polluted) in the upper Olifants River system and two river point, namely, at Mamba and Balule in the Kruger National Park, in the lower Olifants River system. Data was obtained during the physical and chemical analysis of water and sediment samples, and during bioaccumulation studies using Atomic Absorption spectrometry, testing for aluminium, chromium, copper, iron, lead, manganese, nickel, strontium and zinc. These tests were conducted on the liver, skin, muscle and gills of Clarias gariepinus. The information collected from Mamba and Balule, was compared with a previous study carried out primarily in the Kruger National Park by Marx, (1996). The study undertaken by Marx (1996) was carried out during a drought period, which allowed for the comparison with results recorded after flooding during the present study. This current research project therefore allowed for the comparison between two different water sources, namely, that of dams and rivers, and under varying environmental conditions. The Aquatic Toxicity index (ATI) developed by Wepener et al. (1992) was employed to facilitate the comparison between the water physical and chemical parameters that were measured, at each sample site, with a single variable being calculated for each sample site per survey. The water quality (ATI values) at the two control sites namely, Bronkhorstspruit Dam and Balule deteriorated substantially after the floods. High water levels due to the floods had a dilution effect on the concentration of pollutants however, toxicants were washed in from upstream and due to surface runoff. The removal of the purifying reed beds upstream of Balule and at the inflow to Bronkhorstspruit Dam, resulted in the release of latent sludge containing metals and organic pollutants into the water column. The ATI value's obtained for the two control points were similar or even higher than those obtained for the two polluted sites namely at, Loskop Dam and Mamba for the autumn and winter sampling periods. During following surveys the water quality at all four sample sites improved, returning to pre flood values by the last survey in summer, namely reflecting similar values as those recorded by Marx (1996) at Balule, Mamba and Loskop Dam for the same period. Sediment concentrations recorded a similar trend to that for water at all four sample sites throughout the study. The bioaccumulation study indicated that the gill concentrations recorded were generally the highest, followed by the liver concentrations. From this one may deduce that gills were the dominant site for metal absorption by the fish, with the excretion of metals also taking place via this route. Liver concentrations are an indication of the activation of protective _mechanisms in the fish sampled, the high concentrations recorded indicate the high physiological response the fish have had to the various levels of exposure. The low concentrations recorded in the muscle indicates the effectiveness of the liver in the detoxification of the fish, indicating that only limited storage of the various metals tested for took place at this site. Skin concentrations were quite high, these concentrations represent the products of an excretory process, which takes place via the skin. The order of concentrations recorded during the present study, were similar to the orders recorded by Marx, (1996) and other authors, however, the order of the skin and muscle concentrations were often reversed. This may be due to the increased excretion of these metals via the skin, resulting from increased exposure to these metals after the floods. Thus the increased exposure

APA, Harvard, Vancouver, ISO, and other styles

24

Makwarela, Maanda. "Biological monitorings of mining pollution in tributaries of the Olifants River in the Sekhukhune Area." Thesis, 2020. http://hdl.handle.net/10386/3446.

Full text

Abstract:

Thesis (M.Sc. (Zoology)) -- University of Limpopo, 2020 Water pollution has been one of the major concerns all over the world for at least the past two decades. In South Africa, the Olifants River System is one of the most polluted river systems. Anthropogenic activities being carried out within the Olifants River Catchment area pose threats to the aquatic ecosystem. The Upper and Middle catchments are being characterised by intensive mining, industries, agricultural practices and inadequate sewage treatments. Thus, the aim of this study was to investigate the influence of mining activities on the water quality and health status of the Steelpoort River, a tributary of the Olifants River System. This was achieved through assessing the quality of water by analysing physico-chemical parameters, macro nutrients and metals at four selected sites, determining the response of macro invertebrate assemblages to water quality using the South African Scoring System (SASS) version 5 and determining the diversity of fish using the Fish Response Assessment Index (FRAI). Sampling of water, sediment, macro-invertebrates and fish was done seasonally (August 2017 – May 2018) at four selected sites. Site 1 and site 2 were located upstream while site 3 and site 4 were located midstream and downstream respectively. Water and sediment samples were analysed by WATERLAB (PTY) LTD by means of Inductively Coupled Plasma Optical Spectrometry (ICP-OES). Macro-invertebrates were sampled following the SASS protocol. Macro-invertebrates were identified, counted and recorded then released back to the river. Fish were sampled following the FRAI index protocol. The results obtained indicated that the system variables; pH, water temperature, dissolved oxygen and total dissolved solids fell within the target water quality range (TWQR) for aquatic ecosystems. However, some concentrations of macro-nutrients recorded were above the TWQR. These include ammonium at site 3 and nitrogen at sites 2, 3 and 4 which indicated that there was a variation in the influx of macro-nutrients into the river at different river sections. The higher concentrations of ammonium and nitrogen may adversely affect the functioning and survival of biological communities. The metal results indicated that most metals (As, B, Ba, Cd, Cu, Pb, Ni and Cr) fell within the recommended water and sediment quality guidelines (DWAF 1996c; CCME 2012). Chromium concentrations recorded in sediment were above the sediment quality guideline at all the selected sites (CCME 2012). Iron and Zn were also above the guideline values at all selected sites. In terms of physico-chemical parameters and metal concentrations indicated that the water quality of the Steelpoort River was fairly good. The macro-invertebrates were also analysed; their abundance, distribution and family richness indicated that there was a deterioration of water quality from upstream to downstream which may be an indication of increase in influx of pollutants and modifications in the stream such as flow, cover and microhabitat. The highest macro invertebrate abundance and richness was at site 1 while the lowest was at sites 3 and 4. Site 3 was highly modified while site 1 was the least modified site. The Ephemeroptera, Plecoptera and Trichoptera index (EPT) and Ephemeroptera, Plecoptera and Trichoptera/Chironomidae ratio (EPT/C ratio) analysis also confirmed that the water quality of the Steelpoort River is deteriorating from upstream to downstream. Site 1 had the highest value of EPT while site 2 had the highest value of EPT/C. Site 3 had the lowest value for both EPT and EPT/C ratio. The higher EPT and EPT/C ratio indicate the presence of highly sensitive taxa. The Canonical Correspondence Analysis (CCA) indicated a strong correlation between metals (Pb, Cr, Mg, As and Se) and macro-invertebrates (Pleidae, Ecnomidae, Athericidae, Synlestidae, Lestidae and Pyralidae). The SASS 5 results also indicated deterioration of water quality from upstream to downstream with the highest values of SASS score and Average Score Per Taxon (ASPT) being recorded at site 1 followed by site 2 while the lowest SASS score and ASPT were at site 3 followed by site 4. The use of fish as biological indicator also supported the same pattern of water quality deterioration and influx of pollutants which was previously indicated as increasing from upstream to downstream of the Steelpoort River. Site 1 had the highest fish abundance, while site 4 had the lowest fish abundance. However, the fish species richness was highest at site 4 while the lowest species richness was at site 1. The Shannon Weiner Diversity Index also supported that site 4 had the highest fish species richness while site 1 had the lowest species richness. The FRAI results indicated that different sites were in different Ecological Categories (EC). The ECs showed a trend from higher EC category upstream to lower EC category downstream. Site 1 had an EC of C followed by site 2 with an EC of C/D, site 4 with EC of D and then site 3 with the lowest EC of D/E. This might serve as an indication of decrease in habitat availability, increase of pollutants input and increase in stream modification. The CCA showed a weak correlation system variables and fish species. However, a strong correlation was observed between most metals and most fish species with the exception of Mesobola brevianalis Boulenger, 1908, Chiloglanis pretoriae Van Der Horst, 1931, Labeobarbus marequensis Smith, 1841 and Enteromius neefi (Greenwood, 1962). In conclusion, the water in the Steelpoort River is still in relatively good condition. However, increasing mining, industrial and agricultural practices in the catchment area results in increase of pollutants input into the river system. All the four selected sites were contaminated to some degree, with site 3 being the most affected site and site 1 being the least affected site. For this reason, it is important to continuously monitor the health status of the Steelpoort River and to educate the nearby communities who rely on this river for water supply about the quality of the water from the Steelpoort River. DSI-NRF SARCHI (Ecosystem Health)

APA, Harvard, Vancouver, ISO, and other styles

25

Rasifudi, Lwendo. "Bio assessment of water quality using macro-invertebrate communities in the Selati River, Lower Olifants River System." Thesis, 2019. http://hdl.handle.net/10386/3152.

Full text

Abstract:

Thesis (M. Sc. (Zoology)) -- University of Limpopo, 2019 Many South African rivers, including the Ga-Selati River have been deteriorating for the past few decades, due to an increase in mining, industrial, agricultural and domestic activities. Around mid-January 2014, the Ga-Selati River was contaminated by mine spills from a nearby phosphate mine, which polluted the river and killed many fish species. This river is a primary source of water for many activities (e.g. mining, industrial, agricultural and domestic activities), and as a result, large numbers of reservoirs, farm dams, and inter-basin transfer schemes have been constructed to increase the reliability of water supply along this river. Contamination of surface waters by agricultural pesticides and fertilizers, as well as by industrial metals, is a cause of increasing public concern. The Ga-Selati River is a major tributary for the Olifants River, among other tributaries (Steelpoort River and Blyde River) and it plays a significant role in the Kruger National Park and other private game reserves in the catchment. This River is also known to supply water of very low quality into the main stem of the Olifants River. The Olifants River System has been described as degraded and is contaminated with metal and chemicals, and is considered to be one of the most threatened river systems in South Africa. The aim of the study was to investigate the ecological state of the Ga-Selati River and the impact of water and sediment quality on the aquatic invertebrate communities, and to propose measures to prevent further degradation of the river ecosystem by human disturbance. The main objectives were to: (i) establish the current physico-chemical composition of the river water and sediment along the entire length of the Ga-Selati River, (ii) to determine if poor water quality at the lower end of the river is due to pollution inputs in the lower reaches, or the result of cumulative pollution inputs along the entire length of the river, (iii) Assess the impact of water and sediment quality on the aquatic macro-invertebrate assemblages in the river. The concentrations of pH, and DO were high at all sites. If there was any sort of pollution in the river, especially downstream by the mining sites, we expected these two variables to be lower. The water variables such as EC, TDS and salinity showed a gradual increase from upstream to downstream. There were also elevated levels of certain metals, such as Mg, Na, Ti, B, Sr, K and Ca showing a pollution gradient. The v high concentrations of metals in water samples indicate that the Ga-Selati River is heavily impacted downstream by anthropogenic activities such as illegal dumping/littering at site 6 and mining activities at site 7 to site 9. Some of the metal concentration (Na, Mg, K and Ca) in the river were found to be extremely high compared to other rivers in the region. Metal concentrations in sediment samples were very high compared to water samples River. The nutrient concentrations at the Ga-Selati River were high but did not show a pollution gradient. The macro-invertebrate assemblages in the Ga-Selati River were rich in Ephemeroptera, Diptera and Trichoptera. Site 1 and site 2 accounted for most of the sensitive families, reflecting good water quality at these two sites, while site 9, a downstream site recorded the highest number of tolerant families.. The variations in the macro-invertebrate distribution were shown by the differences in the water quality at the various sites by the CCA plot. The effects of main pollution factors such as, EC, TDS, turbidity and nutrients were correlated with the distribution of tolerant taxa. National Research Foundation (NRF) and Vlir

APA, Harvard, Vancouver, ISO, and other styles

26

Mulanga, Tshimanga Christelle. "Investigation of selected organic compounds on water quality along the Olifants river catchment." Diss., 2016. http://hdl.handle.net/10500/22294.

Full text

Abstract:

Water is a crucial natural resource, indispensable to food production, life, the environment, power generation, industry, sanitation and hygiene. The presence of Organochlorine Pesticides (OCPs) in the environment is not wanted due to their negative effects on human beings and animals. As a result, there is a need to continuously monitor their presence in the environment. In this study, surface water samples were collected once a month during the dry season and during wet season from the selected five points along the Olifants River and stored at a temperature of < 50C before analysis. The OCPs were extracted with dichloromethane (DCM) using the Liquid-Liquid Extraction (LLE) method. After undertaking the sample through the clean- up process, the crude extracts obtained were put into the column chromatography and eluted with hexane, about 1.5 μL of the purified extracts were analysed by the Gas Chromatographic- Mass Spectrophotometer (GC/MS). The percentage recoveries, varied from 32- 116 % for p, p’-DDT and 4,4'-DDD respectively in triply spiked water samples. The standard deviation for most of the compounds is less than±0.04, with the exclusion of Heptachlor (±0.14). The seasonal variability of OCPs in water samples along Olifants River results show that in dry season, the Olifants River is mostly polluted at the Oxford site with (BHC-beta, Aldrin, Heptachlor-epoxide, Endosulfan-alpha and Endrin), at the Ga- Selati site with (Heptachlor-epoxide and Endrin) and at the Wolvekrans site with (Endosulfan-alpha), with Aldrin up to 834.20 ng/ L indicating the highest hazard toward the aquatic environment while in summer the Olifants River is mostly polluted at the Ga- selati site with BHC-beta and at the Waterval site with (Heptachlor and BHC-gamma) with BHC- gamma up to 560 ng/ L indicating the highest hazard toward the aquatic environment. The levels reached from the Olifants River catchment were meaningfully above the drinking water quality guidelines for organic chemical recommended by WHO, 2006 i.e. (BHC-gamma,DDT-44, Aldrin, dieldrin and Endrin are (2.0,1.0,0.03,0.03 and 0.6) respectively for the protection of the domestic use, aquatic ecology and agricultural use (irrigation and livestock watering) for compounds with local guideline values; while, the international water quality guidelines to protect the aquatic ecosystems are 0.00083 ng/mℓ (4,4’DDD), 0.00059 ng/mL (4,4’DDE), (4,4’DDT), 0.00021 ng/mL (heptachlor), 0.0092 ng/mℓ (α-HCH), 0.0186 ng/mL (γ- HCH), and chronic values are 0.056 ng/mL (ENDO I and II) and 0.0023 ng/mL endrin) (USEPA, 2002). Levels detected were significantly higher than some research studies conducted up to now in South African aquatic environments. These results confirm the contamination of the Olifants River catchment by the OCPs. Water and Sanitation M. Sc. (Environmental Science)

APA, Harvard, Vancouver, ISO, and other styles

27

Mmako, Tebatso Vinolia. "Assessment of the impact of water and sediment quality on the diversity of aquatic macro-invertebrate communities in the Dwars River of the Olifants Rivers system, Limpopo Province." Thesis, 2019. http://hdl.handle.net/10386/3452.

Full text

Abstract:

Thesis (M.Sc. (Zoology)) -- University of Limpopo, 2019 Freshwater ecosystems in South Africa are losing their quality and quantity over time due to pollution mainly from mining, agriculture, industries, deforestation, sewage systems, construction of dams, channel modification and over extraction of water. The Dwars River, a tributary of the Olifants River, is of no exception, as recent studies indicated an increase in nutrient input possibly from agriculture. The Dwars River is an important source of water for nearby communities (Ga-Mampuru). The aim of the study was to assess water and sediment quality of the Dwars River using macroinvertebrates as bioindicators of pollution. Water and macroinvertebrates sampling were done seasonally from July 2017 to May 2018. The water quality results indicated that non-toxic constituents such as salinity and EC (Electrical Conductivity) were above permissible limits stipulated by the DWAF (1996) guidelines. More sensitive taxa were found upstream, despite high concentrations of some nutrients and metals in the water column. The high abundance and distribution of macroinvertebrates observed upstream was confirmed by the Canonical Correspondence Analysis (CCA), South African Scoring System (SASS5) and Average Score Per Taxon (ASPT) results during the study. Site 1 was dominated by the most sensitive taxa and this could be due to high dissolved oxygen content and increased heterogeneity of the area. Site 4 was dominated by the most tolerant taxa, according to the CCA, SASS score and ASPT results. This could possibly be due to the nutrients and heavy metals washed from upstream, which get adsorbed by the sediment. The results for species abundance, diversity and richness indicated that Ephemeroptera was the most abundant, while Diptera was the most diverse. Ephemeropterans are known to be indicators of good water quality. Site 1 had the highest number of families and orders while site 4 had the least families and orders. Ephemeroptera, Plecoptera and Tricoptera (EPT) taxa richness and Shannon diversity (H’) index values are high upstream and decrease downstream. Overall, the SASS5 indices, CCA and physicochemical results indicated that the water quality in the Dwars River is deteriorating in most impacted sites National Research Foundation (NRF) and VLIR

APA, Harvard, Vancouver, ISO, and other styles

28

Nussey, Gail. "The effect of copper on the blood coagulation and general haematology of Oreochromis mossambicus (cichlidae)." Thesis, 2014. http://hdl.handle.net/10210/9997.

Full text

Abstract:

M.Sc. (Zoology) A number of chemical substances in mining, industrial, agricultural and domestic effluents are likely to contaminate watercourses. These toxicants have a definite effect on all aquatic life, even at sublethal concentrations. Due to the extensive copper mining activities in the Phalaborwa region, there is concern that the sublethal effect of copper might affect the physiology of fish in the Olifants River, Kruger National Park, Transvaal. Copper can be found as an essential micronutrient in nearly all waters, although anthropogenic sources such as metals from mining and planting industries might produce environmental concentrations causing toxic effects to fish. Several effects of exposure to sublethal concentrations of copper have already been reported in fish, In the present study, the blood coagulation, general haematology, osmoregulation and differential white blood cell counts of the Mozambique tilapia, Oreochromis mossambicus were investigated after the exposures to sublethal concentrations of copper, for a short-term (96 hours) exposure as well as a long-term (four weeks) exposure in experimental flow through systems, at both 29 ± I°C and 19 ± I°C. After the respective sublethal exposures, changes in the values of blood coagulation, general haematology, osmoregulation and differential white blood cell counts were obtained, to determine the effects of the chosen copper concentrations on the blood physiology of O. mossambicus, at 29 + 10 and 19 ± I°C, respectively. After a photographic observation of blood, during all the phases of coagulation was made, it was evident that the exposure to copper, at both temperatures, resulted in delays of the blood coagulation times as well as decreases in the elasticity of the clots that formed. Copper was found to induce haemophilia at 29 ± I°C and 19 ± l°C. whilst at 19 ± I°C it also induced thrombocytopenia. Thus exposure to copper lead to coagulation defects which caused haemorrhage which can eventually cause the death of these fish...

APA, Harvard, Vancouver, ISO, and other styles

29

Idowu, Olufemi Abiola. "Impact of irrigation with gypsiferous mine water on the water resources of parts of the upper Olifants basin." Thesis, 2007. http://hdl.handle.net/10413/3429.

Full text

Abstract:

The generation of large quantities of mine wastewater in South African coal mines and the needs for a cost effective, as well as an environmentally sustainable manner of mine water disposal, have fostered interests in the possibility of utilizing mine water for irrigation. Such a possibility will not only provide a cost-effective method of minimizing excess mine drainage, as treatment using physical, chemical and biological methods can be prohibitively expensive, but will also stabilize the dry-land crop production by enhancing dry season farming. Considering the arid to semi-arid climate of South Africa, the utilization of mine water for irrigation will also boost the beneficial exploitation of the available water resources and relieve the increasing pressure on, and the competition for, dwindling amounts of good quality water by the various sectors of the economy. The disposal of excess gypsiferous mine water through irrigation has been researched in a few collieries in the Witbank area. In this study, the assessment of the impacts of using gypsiferous mine water for irrigation were carried out in parts of the Upper Olifants basin upstream of Witbank Dam, using the ACRU2000 model and its salinity module known as ACRUSalinity. The study area was chosen on the bases of locations of previous field trials and the availability of mine water for large-scale irrigation. The primary objectives of the study were the development of relevant modules in ACRU2000 and ACRUSalinity to enable appropriate modelling and assessment of the impact of large-scale irrigation with mine water and the application of the modified models to the chosen study area. The methodology of the study included the modifications of ACRU2000 and ACRUSalinity and their application at three scales of study, viz. centre pivot, catchment and mine scales. The soils, hydrologic and salt distribution response units obtained from the centre pivot scale study were employed as inputs into the catchment scale study. The soils, hydrologic and salt distribution response units obtained from the catchment assessment were in turn applied in similar land segments identified in the mine used for the mine scale study. The modifications carried out included the incorporation of underground reservoirs as representations of underground mine-out areas, multiple water and associated salt load transfers into and out of a surface reservoir, seepages from groundwater into opencast pits, precipitation of salts in irrigated and non-irrigated areas and the incorporation of a soil surface layer into ACRUSalinity to account for the dissolution of salts during rainfall events. Two sites were chosen for the centre pivot scale study. The two sites (Syferfontein pivot of 21 ha, located in Syferfontein Colliery on virgin soils; Tweefontein pivot of 20 ha, located in Kleinkopje Colliery on rehabilitated soils) were equipped with centre pivots (which irrigated agricultural crops with mine water), as well as with rainfall, irrigation water and soil water monitoring equipment. The pivots were contoured and waterways constructed so that the runoff could leave the pivots over a weir (at Tweefontein pivot) or flume (at Syferfontein pivot) where the automatic monitoring of the quantity and quality of runoff were carried out. The runoff quantities and qualities from the pivots were used for verification of the modified ACRU2000 and ACRUSalinity. The catchment scale study was on the Tweefontein Pan catchment, which was a virgin area mainly within the Kleinkopje Colliery, draining into the Tweefontein Pan. The data on the water storage and qualities in Tweefontein Pan, as well as the soil water salinities in the irrigated area located within the catchment were used for verification of results. In the catchment scale study, different scenarios, including widespread irrigation on virgin and rehabilitated soils, were simulated and evaluated. For the mine scale study, the Kleinkopje Colliery was used. The colliery was delineated into 29 land segment areas and categorized into seven land use types, on the basis of the vegetation and land uses identified in different parts of colliery. The centre pivot and catchment scale studies indicated that the impacts of irrigation with low quality mine water on the water resources are dependent on the soil types, climate, the characteristics and the amount of the irrigation mine water applied, whether irrigation was on virgin on rehabilitated soils and the status of the mine in terms of whether a regional water table has been re-established in an opencast mining system or not. The studies further indicated that the irrigation of agricultural crops with low quality mine water may lead to increases in soil water salinity and drainage to groundwater, but that the mine water use for irrigation iii purposes can be successfully carried out as most of the water input onto the irrigated area will be lost through total evaporation and a significant proportion of the salt input, both from rainfall and irrigation water, will either be precipitated in the soil horizons or dissolved in the soil water of the soil horizons. By irrigating with a saline mine water therefore, the salts associated with the low quality mine water can be removed from the water system, thereby reducing the possibility of off-site salt export and environmental pollution. On-site salt precipitation, however, may lead to accumulation of salts in the soil horizons and consequent restriction of crop yields. Therefore, efficient cropping practices, such as leaching and selection of tolerant crops to the expected soil salinity, may be required in order to avoid the impact of long-term salinity build up and loss of crop yields. The simulated mean annual runoff and salt load contribution to Witbank Dam from the Kleinkopje Colliery were 2.0 x 103 MI and 392 tons respectively. The mean annual runoff and salt load represented 2.7% and 1.4% of the average water and salt load storage in Witbank Dam respectively. About 45% of the total water inflow and 65% of the total salt load contribution from the study area into Witbank Dam resulted from groundwater storage. From the scenario simulations, the least salt export would occur when widespread irrigation is carried out in rehabilitated areas prior to the re-establishment of the water table due to a lower runoff and runoff salt load. It may therefore be a better water management strategy in active collieries if irrigation with mine water is carried out on rehabilitated soils. In conclusion, this research work has shown that successful irrigation of some (salt tolerance) crops with low quality mine water can be done, although increases in the soil water salinity of the irrigated area, runoff from the irrigated area and drainage to the groundwater store can occur. Through the modifications carried out in the ACRU2000 model and the ACRUSalinity module in this research work, a tool has been developed, not only for application in the integrated assessment of impact of irrigation with mine water on water resources, but also for the integrated assessment and management of water resources in coal-mining environments in South Africa. Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2007.

APA, Harvard, Vancouver, ISO, and other styles

30

Watson, Raylene Mullineux. "Evaluation of a fish health assessment index as biomonitoring tool for heavy metal contamination in the Olifants River catchment area." Thesis, 2012. http://hdl.handle.net/10210/7570.

Full text

Abstract:

Ph.D. The current study evaluated a bio-monitoring technique developed in the USA by Adams, Brown and Goede, 1993. This project was sponsored by the Department of Water Affairs and Forestry (DWAF), to enable testing of the Health Assessment Index (HAI) under South African conditions. Testing took place in the Olifants River system, one of the most polluted river systems . in South Africa. Initially two river points were tested using Oreochromis mossambicus (Robinson, 1996), Clarias gariepinus (Marx, 1996) and Labeo rosae (Luus-Powell, 1997). The current study re-tested the HAI at the same two sample sites, namely Mamba and Balule in the Kruger National Park, using 0. mossambicus and C. gariepinus respectively. Two additional sites were tested in the upper catchment area, namely Loskop Dam and Bronkhorstspruit Dam. The current study further enabled the comparison of HAI results collected during drought and flood conditions. Results obtained after deployment of the HAI were corroborated using chemical analysis of water, sediment and biota. Water and sediment analysis was carried out by the Institute for Water Quality Studies using standard techniques. Bio-accumulation of aluminium, copper, iron, lead, manganese, nickel, strontium and zinc was assessed in the gills, liver, skin and muscle tissue of sample fish using standard Atomic Absorption Spectrometry techniques. Modifications made to the original HAI involved the inclusion of variable ranking in the assessment of fish parasites, with endo- and ectoparasites evaluated separately. Testing of this parasite hypothesis lead to the development of a Parasite Index component to the HAI. Assessment of water, sediment and fish tissue determined that the Olifants River system is indeed exposed to macro and heavy metal pollutants, which negatively affect aquatic health. Constituents posing the greatest threat are chlorides, fluorides, phosphates, total dissolved solids, copper and iron concentrations. Testing the HAI and parasite hypothesis using C. gariepinus, provided the most meaningful results. During testing of the parasite hypothesis both endo- and ectoparasite numbers conformed to the suggested idea that higher endoparasite numbers will occur at highly impacted areas, whereby ectoparasite numbers will be low. This was particularly evident in the lower catchment area, whereby comparisons between drought and flood conditions were carried out. Subsequent decreases in water quality directly after the flood were noted using water and sediment analysis. This observation reflects the results gathered using the HAT and during testing of the parasite hypothesis at all four sample sites. During statistical analysis of the HAI, using logistic regression analysis, parasite numbers, more specifically endoparasite numbers, were the most indicative of fish health. Environmental stressors (flood conditions) result in immunological responses observed in fish, and are reflected statistically using the HAI as changes in WBC %. It is suggested that endoparasites and WBC % provide the best overall assessment of fish condition. These variables should thus not be eliminated, in order to streamline the HAI evaluation procedures. Testing of this bio-monitoring technique under South African conditions provided meaningful results. This indicates that the HAI can be used to assess water quality, with existing water monitoring programmes further benefiting from its incorporation.

APA, Harvard, Vancouver, ISO, and other styles

31

Makushu, Elelwani Tabitha. "Fish, water and sediment quality as indicators of land-use change in the Steelpoort River (Olifants River System, Limpopo Province)." Thesis, 2018. http://hdl.handle.net/10386/2265.

Full text

Abstract:

Thesis (M.Sc. (Zoology)) -- University of Limpopo, 2018 This study aimed to determine the effects of water and sediment quality on fish and the effects of land-use on the water and sediment quality of the Steelpoort River system. To achieve these aims, a few objectives had to be met. The water and sediment quality, the level of metal bioaccumulation of two fish species, the level of acetylcholine esterase inhibition in fish brain tissue, as well as changes in land-use over time. The study adds value in the scientific knowledge of the Steelpoort catchment given that there’s little information about it. It is thus a good baseline, which gives direction for further studies conducted within this catchment. The Steelpoort River, is a tributary of the Olifants River system. The Olifants River (Mpumalanga and Limpopo provinces) is a river stressed by anthropogenic activities with the Steelpoort River being a major sub-catchment. The Steelpoort catchment is filled with mines, agricultural activities, and other developments, such as, the construction of a new dam (De Hoop Dam opened 2014), residential areas and malls. The mines within the catchment are mostly platinum and chrome mines. Sampling was conducted for high and low flow at five sampling sites: Two upstream sites, 1 and 2, and three downstream sites 3, 4, and 5. Site 1 is the reference site for the study as this section (ecoregion) was described as “least threatened”. It was hypothesised that high concentrations of metals and nutrients would be present in the water and sediment, and that the metal would be present in fish tissue and would have an effect on human health, that the biomarker AChE would show signs of inhibition within brain tissue, and lastly that land-use characteristics would have an effect on the water and sediment quality, and inhibition of AChE. Water and sediment samples were collected quarterly over a period of a year at five sites, whereas fish samples (Chiloglanis pretoriae and Labeobarbus marequensis) were only collected bi-annually at three sites. The physico-chemical, nutrients, cations and ions, and metals and metalloids were determined. The two fish species were used for metal bioaccumulation and AChE analyses. Human health risk and bio-concentration factor (BCF) analyses were conducted. Using the land-cover details obtained from South African National Biodiversity Institute (SANBI), Department of Environmental Affairs (DEA) and The Council for Scientific and Industrial Research (CSIR), land-use characteristics were determined and evaluated. The in-situ physico-chemical parameters assessed in this study were found to be within acceptable limits of the Target Water Quality Range (TWQR) at all the sites. The Electrical Confuctivity (EC) and Total Disolved Solids (TDS) parameters were highest at Site 5 and lowest at Site 1, this could be due to Site 5 being the last site before the Steelpoort River connects to the Olifants River, hence this site recieves all the ions and solutes from upstream; and the lowest value at Site 1 could be attributed to this site having the least number of lan-use effects. For nutrients, the highest total nitrogen concentration was recorded at Site 5 and the highest phosphate concentration at Site. This river is mesotrophic according to both the total inorganic nitrogen and phosphorus levels. Metals in the water column that were above DWAF guidelines for Aquatic Ecosystems were Al, Ba, Mn and Zn. In the sediment the following metals were above the Canadian sediment quality guidelines: Cd, Cu, Cr and Zn, which can pose a threat to the health of fish through biomagnification through the food chain. Both C. pretoriae and L. marequensis had bioaccumulated metals from the river system. The concentrations of metals in the muscle tissue of C. pretoriae where higher and this could be due to the fact that unskinned samples were used in the case of C. pretoriae. A variety of metals were present in both fish species but Al, Fe, Sr and Zn were present in higher concentrations. Concentrations of metals were highest in samples from Site 5 The human health risk assessment revealed that Pb could cause health related impacts to the humans who consume a single 150 g fish meal once a week in C. pretoriae; and that Co could cause potential risks in the near future. The BCF values revealed that there were more bioconcentrated metals in C. pretoriae than in L. marequensis and this could also be due to different diets. The AChE activity was higher for L. marequensis during high flow at all sites and higher at Site 1 during low flow but lower at Site 5 and equivalent at Site 2 than the AChE activity recorded for C. pretoriae. This could be due to the ability of L. marequensis to expel pesticides from their system before the pesticides affect brain activity by decreasing the function of AChE. Both fish species had more AChE activity during low flow for sites 1 and 2 than during high flow. The high flow AChE activity was higher for Site 5 in both fish species. The results confirm the hypotheses were that metals would be present in fish tissue and would have an effect on human health; and that the biomarker AChE would show signs of inhibition within brain tissue. The agricultural activity has decreased over time within the catchment, from 2000 to 2014 and this could be due to a decrease of fertile land. There has also been a decrease in the mining activity from 2000 to 2009 and then an increase during 2014, where the decrease could be due to the closure of mines at the end of their life span; and the increase in 2014 could be due to the opening of new mines. Residential areas have increased from 2000 through to 2014. The availability of water decreased from 2000 to 2009, and then increased drastically in 2014. The drastic increase is due to the multiple dams that have been built over time in order to provide water resources to the increased population, and also for mining and irrigation purposes. The water quality showed an increase in the NO3, SO4 and PO4; meanwhile the EC has decreased over time. The decrease in EC means that there are fewer ions in the river. The increase in phosphates and nitrates could mean there is a lot of fertilizers and pesticides being used in agriculture even with the decrease in agricultural land-use over the years. The pesticides can also be due to the increase in residential areas, where pesticides are also used to get rid of pests.

APA, Harvard, Vancouver, ISO, and other styles

32

Uken, Ronald. "The geology and structure of the Bushveld Complex metamorphic aureole in the Olifants River area." Thesis, 1998. http://hdl.handle.net/10413/4654.

Full text

Abstract:

The contact metamorphic aureole of the Rustenburg Layered Suite of the Bushveld Complex extends to a depth of over 5 km into the underlying mainly argillaceous Pretoria Group. When compared to other parts of the metamorphic aureole, the Olifants River area is unique in that it is characterised by a high degree of syn-Bushveld Complex deformation and very coarse grained pelitic assemblages. This is believed to have resulted from a combination of greater magma thickness, a deeper emplacement depth and a high degree of subsidence related deformation that was focused along the Thabazimbi-Murchison Lineament. This area also contains a laterally extensive and deformed quartz-feldspar porphyry sill, the Roodekrans Complex that is shown to represent a hypabyssal equivalent of the volcanic Rooiberg Group. There are three main metamorphic zones. A wide andalusite zone dominated by staurolite, garnet and cordierite assemblages. This is followed by a narrow fibrolite zone without staurolite, and a wide inner aureole of migmatite. The migmatite zone is characterised by garnet-cordierite-aluminosilicate assemblages with corundum, spinel and orthopyroxene assemblages at the highest grades. Metamorphic pressure and temperature estimates indicate pressures of between 3 kb and 4 kb in the lower part of the andalusite zone at temperatures of approximately 550°C. Porphyroblast-matrix relationships reveal a close link between deformation and metamorphism resulting in a spectrum of textural relationships developed as a result of inhomogeneous strain. Porphyroblasts in low strain domains preserve textures of “static type" growth whereas syntectonic textures are found in foliated rocks. Pre-tectonic porphyroblasts in many foliated domains indicate that deformation outlasted porphyroblast growth and increased in intensity and extent with time. Retrograde porphyroblasts are post-tectonic. Evidence is presented for both rotation and non-rotation of porphyroblasts in relation to geographical coordinates during extensional top-to-south, down-dip shear in the floor. The unique structural setting in this area triggered the growth of large diapiric structures in the floor of the Rustenburg Layered Suite that are preserved as periclinal folds on the margin and within the northeastern Bushveld Complex. Extreme gravitational loading and heating of the floor by a thickness of up to 8 km of mafic magma resulted in the generation of evenly spaced, up to 7 km diameter wall-rock diapirs that penetrated the overlying magma chamber. Diapiric deformation is restricted to rocks above a decollement zone that is developed along competency contrasts and corresponds approximately with the 550 °C peak metamorphic isotherm. Strongly lineated, boudinaged and foliated rocks are developed in the interpericlinal domains between adjacent periclines. Migmatites in these domains are characterised by conjugate extensional ductile shears and associated asymmetrical boudinage suggesting bulk deformation by pure shear processes. The extension lineation was produced by lateral extension along flow lines directed toward dome culminations. Each of the four diapiric periclines is cut by a different erosional section enabling reconstruction of a typical diapir geometry. At the highest structural levels, periclines have bulbous shapes with overturned limb geometries forming overhangs. The surrounding layered igneous rocks are locally deformed into a series of outward verging folds that define a broad rim syncline. Deformation within the pericline cores is represented by constrictional deformation that produced radial curtain-type folds with steeply plunging lineations and concentrically orientated folds in the outer shell. Diapirism is closely linked to magma emplacement mechanisms. Floor folds in the country rocks were initiated in the interfinger areas of a fingered intrusion. With further magma additions and the coalescence of intrusion fingers into a single sheet, interfinger folds matured into large diapiric periclines which rose to the upper levels of the magma chamber. Strain rates estimated from strain analyses, pericline geometry and model cooling calculations are in the order of 10-14 S-1, corresponding to diapiric uplift rates of 0.6 cm/yr. Diapirism is broadly compatible with a N-S extension in the Olifants River area during emplacement of the Rustenburg Layered Suite. On a regional scale, this is indicated by existence of a major EW dyke swarm that coincides with the long axis of the Bushveld Complex. The accommodation of the Bushveld Complex into the Kaapvaal Craton was facilitated by a combination of craton-wide extension that accompanied plume related magmatic underplating, and loading of the Bushveld Complex. Isostatic adjustment in response to Bushveld Complex subsidence resulted in further development of large basement domes around the perimeter of the Bushveld Complex. Thesis (Ph.D.)-University of Natal, Durban, 1998.

APA, Harvard, Vancouver, ISO, and other styles

33

Kotze, Petrus Jacobus. "Aspects of water quality, metal contamination of sediment and fish in the Olifants River, Mpumalanga." Thesis, 2012. http://hdl.handle.net/10210/6074.

Full text

Abstract:

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.

APA, Harvard, Vancouver, ISO, and other styles

34

Zermatten, Carrie. "The role of legislation and management practices in the coal mining industry on the Olifants River catchment, South Africa." Diss., 2012. http://hdl.handle.net/2263/29626.

Full text

Abstract:

The economic development of South Africa has relied heavily on coal mining and water quality is adversely affected by mining - thus coal mining poses a significant risk to South Africa’s water resources. Ensuring judicious use and management of natural capital is always a complex undertaking but the benefits to the mining industry and society as a whole, derived from thoroughly laid-out plans, a supportive but strict regulatory environment and decision-making processes based on sound, scientific information are immense. Value addition to mining products is important to promote conservation of assets and resources. Using the Olifants Water Management Area as a case study, the chemistry of groundwater associated with coal mining was characterised. General concepts regarding the relationship of geology to water chemistry are surmised. Copyright Dissertation (MSc)--University of Pretoria, 2012. Geology unrestricted

APA, Harvard, Vancouver, ISO, and other styles

35

Visser, Zola. "The use of biomarker responses to assess pesticide exposure in the Crocodile- and Olifants River systems." Thesis, 2010. http://hdl.handle.net/10210/3278.

Full text

Abstract:

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.

APA, Harvard, Vancouver, ISO, and other styles

36

Wepener, Victor. "Metal ecotoxicology of the Olifants River in the Kruger National Park and the effect thereof on fish haematology." Thesis, 2012. http://hdl.handle.net/10210/7334.

Full text

Abstract:

D.Phil. By virtue of its position on the eastern border of South Africa, the Kruger National Park (KNP) receives the flow of six main riven, of which the greater part of the specific catchment areas are situated upstream from the park itself. The Olifants River has the largest catchment area both in size and in proportion of catchment area beyond the park boundary. Increased competing demand for water by the urban, industrial, mining and agricultural sectors within the catchment boundaries of the Olifants River has focused attention on the ecological water requirements of the river. Of particular concern was the high degree of mineralisation of the Olifants River due to mining activities on the western boundary of the KNP. When one considers the demand for water by the Kruger National Park it is evident that water is required for more than one use, i.e. for potable use, game watering and ecosystem (aquatic and riparian) maintenance. In order to facilitate proper water quality management it is necessary to develop a comprehensive water quality management plan for the river. The development of such a plan requires a thorough understanding of the fate and effects of pollutants in the environment. It is furthermore important to have reliable information on the trends and status of important water quality determinants in these systems. This study was therefore aimed at investigating the metal ecotoxicology of the lower Olifants River and the Selati River, a tributary of the Olifants River which flows through the Phalaborwa area. Water quality is a driving variable in aquatic ecosystems. Full assessment of water quality of the Olifants River included evaluation of the physical, chemical and biological attributes of the system. The difference between the physical/chemical and biological attributes is that the former provide an instantaneous and often specific assessment of the water quality, whereas the latter integrate changes in the system over time. Water and sediment samples were collected bi-monthly from February 1990 to February 1992 at six stations along the lower Olifants River, one in the Selati River and one in the Letaba River. At each of these sites physical and chemical water quality characteristics were measured. Two metal bioaccumulation indicator species, Labeo rosae and Oreochromis mossambicus, were also sampled during the same period at three stations in the Olifants River and at the Selati River sampling station. Two additional surveys were undertaken to reference sites in the KNP (i.e. Pioneer Dam, and Nhlanganini Dam) during February 1992 and April 1992 respectively. Tissue samples (muscle, gill, liver, gonads, fat and blood) were collected and analysed for Cr, Cu, Fe, Mn, Ni, Pb and Zn using atomic absorption spectrophotometry. The routine monitoring of chemical and physical water quality attributes produces large quantities of complex data which are often difficult to interpret. To reduce the complexity, data may be standardised and summarised into an index. The Aquatic Toxicity Index (ATI) that was developed Metal Ecotoxicology in the Olifants River it Summary during this study presented the water quality of all the sampling stations, during each survey as a single value. This value reflected the water quality's suitability-for-use by fish at the different sampling stations. The ATI showed definite temporal and spatial trends in water quality in the Olifants River. The Selati River was the main contributing factor to the poor water quality measured in the Olifants River within the KNP. This was due to high TDS, metal and fluoride concentrations. Deterioration of the water quality was experienced during flood conditions when the turbidities and total metal concentrations increased. The water quality generally increased between summer and winter surveys (February to June). Bioindicators are species used to quantify biologically available level of metals in the aquatic ecosystem. These organisms take up metals from the ambient water and from food, and the concentrations in their tissues (or changes in concentrations) provide a time integrated measure of metal bioavailability. Temporal bioavailability of metals in the tissues of the bioindicators showed similar trends to the water quality. Highest metal concentrations were measured in fish tissue samples collected during flood conditions (December 1990) and during low-flow conditions (June to October). This was attributed to increased exposure due to metal adsorption to suspended sediments during the flood conditions and to increased ambient metal concentrations during lowflow conditions. The distribution of metals in tissues varied based on the uptake, depuration and metabolism strategies for each metal. In general the gill tissue bioaccumulated the highest metal concentrations, with only Cu and Fe occurring in higher concentrations in liver tissue. Significant positive correlation's were found between bioaccumulation in muscle tissue and the other tissues: Space-bulking and time-bulking of results were carried out to elucidate spatial bioaccumulation patterns. The highest bioaccumulation of Cu, Pb and Ni were recorded in samples from the Selati River, whereas Zn and Cr concentrations were the highest in the Olifants River. An equilibrium partitioning (EP) technique was used to integrate bioaccumulation data and metal concentrations in different phases of the water and sediment and produce specific Cu and Zn criteria for the Olifants and Selati rivers. Although there is a multitude of data available for Cu and Zn toxicity and BCF's, the quality criteria produced during this study, for the first time, made use of results obtained under local conditions. The results from bioaccumulation studies carried out in the field can not provide information regarding the potential effects or the risks the metals may pose to the exposed organisms. Therefore the susceptibility of the organisms to metal contamination can be determined using laboratory studies. Physiology is toxicology's closest relative and contributes markedly in assessing the toxicological risk of metals. Bioassays were conducted to determine the uptake kinetics, acid-base disturbances and haematological effects of a metal mixture containing Cu, Fe and Zn on Tilapia sparrmanii. The effects of the individual metals (Cu, Fe and Zn) and different Metal Ecotoxicology

APA, Harvard, Vancouver, ISO, and other styles

37

Malakane, Karabo Concelia. "Assessment of the impact of water and sediment quality on aquatic macroinvertebrate assemblages in the Blyde River of the Olifants River System, Limpopo Province." Thesis, 2019. http://hdl.handle.net/10386/2938.

Full text

Abstract:

Thesis (M.Sc. (Zoology) -- University of Limpopo, 2019 The Olifants River is one of the major river systems in South Africa, providing water for industries, mines, agricultural and domestic activities. Consequently, the river has turned out to be one of the most polluted rivers in South Africa. The Blyde River is an important tributary of the Olifants River, known for its continuous flow and good water quality. However, the recent increase in human activities such as, commercial agricultural and large-scale forestry practices in the catchment may have a negative impact on the quality of the water, which may consequently affect the aquatic biota community structure. The aim of the study was to assess the water and sediment quality of the Blyde River using aquatic macroinvertebrates as bioindicators and the South African Scoring System version 5 (SASS5) protocol was followed. Seven sampling sites were selected at Blyde River and five samples were collected per site. Collected macroinvertebrates were identified to family level and classified according to their tolerance levels to pollution at the University of Limpopo Biodiversity Laboratory. In addition, seasonal readings of the physico-chemical parameters such as, pH, dissolved oxygen (DO), temperature, salinity, total dissolved solutes (TDS) and electrical conductivity (EC) were recorded in situ using YSI Model 554 Datalogger with a 4 m multiprobe and a Mettler Toledo SevenGo™. Most of the physico-chemical parameters recorded at Blyde River were within the South African water quality guidelines for aquatic ecosystems. Metals such as, As, Al, Ba, B, Cd, Cr, Co, Cu, Fe, Pb, Mn, Ni, Se, Ag, Sr, Sn, Ti, V, and Zn were tested from the water column, sediments and macroinvertebrate tissue. Almost all the metals analysed from the water column and sediments were within the quality guidelines. Out of the twenty tested metals, As, Ag, Cu, and Zn exceeded the recommended quality guidelines in the water column at some sites. Only As, Cr and Cu exceeded the recommended quality guidelines in the sediments. The most abundant macroinvertebrates were from the orders Ephemeroptera, Diptera, and Trichoptera at all sites. There was a similar macroinvertebrate community structure across the sites, supported by the positive correlation analysis among the sites (r > 0.4). Wildlife Estate and Wildrivers Estate had the highest and lowest numbers of sensitive macroinvertebrates respectively. The highest percentage of iv sensitive macroinvertebrate taxa was recorded in winter and the highest percentage of tolerant species was recorded in summer. This was also supported by the SASS indices, the SASS score, number of taxa and average score per taxon (ASPT) were highest in winter, followed by autumn, spring and lowest in summer. The overall SASS indices showed that the water quality condition at most of the sites at Blyde River could be considered as good. All the seven sites on average fell under ecological band A and B, except for the Wildrivers Estate, thus, the water quality status of the river could be described as unmodified and largely natural with few modifications. VLIR

APA, Harvard, Vancouver, ISO, and other styles

38

Seymore, Tharina. "Bioaccumulation of metals in Barbus marequensis from the Olifants River, Kruger National Park and lethal levels of manganese to juvenile Oreochromis mossambicus." Thesis, 2014. http://hdl.handle.net/10210/10555.

Full text

Abstract:

M.Sc. (Zoology) The catchment area of the Olifants River is being subjected to increased agricultural and mining activities, industrial development and urbanisation. As a result of this, the water quality 'of the Olifants River and some of its tributaries (e.g. Selati River) has been deteriorating since 1983. This causes reason for concern as one of the downstream water users in the Olifants River catchment is the Kruger National Park, which requires of good quality to sustain its terrestrial and aquatic ecosystems It was therefore necessary to determine what extent activity midstream-or--tlie I Olifants River, especial y in the Phalaborwa area, influenced the water quality of the Olifants River. In this study, an evaluation was done of the water quality (physically and chemically of the Lower Olifants River inside of the Kruger National Park, as well as the Lower Selati River, a tributary of the Olifants River which flows through the Phalaborwa area. Special attention was paid to the metal concentrations in the water, sediment and fish. Water and sediment were sampled every alternate month from April 1990 to February 1992 at six sampling sites along the Lower Olifants River and one in the Selati River. Standard methods were used to determine the physical and chemical characteristics (e.g. pH, TDS, etc.) of the water. The fish species Barbus marequensis was also sampled every alternative month, but only at three sampling sites along the Olifants River and one in the Selati River. Organs and tissues that were dissected, included the gills, fat, liver, gonads, gut, muscle, skin, blood, vertebrae, kidney and bile, as well as the gut contents. In February 1992, additional sampling was performed at Pioneer Dam, a natural reference point used in this study. Atomic absorption spectrophotometry was used in the laboratory to determine the Cr, Cu, Fe, Mn, Ni, Pb, Sr and Zn concentrations in the water, sediment and fish samples. (The water quality of the Selati River was found to be stressful to aquatic life, especially .) with regard to the sodium, fluoride, chloride, sulphate, potassium, total ~dissolved salts 1 and metal concentrations (except strontium). The Selati River also influenced the ': water quality of the Olifants River after the Selati-Olifants confluence. Most of the :. time the water quality of the Lower Olifants River in the KNP did, however, comply With the recommended guideline limits, except for the metal concentrations. The high metal concentrations detected in the water (in some cases sub-lethal levels) indicated some degree of metal pollution, but, due to the hardness of the Olifants River water, conditions were not necessarily toxic to the aquatic life. The accumulated metals in the organs and tissues of marequensis gave a good indication of the metal levels to which the fish were exposed. More metals were taken up by the fish from April 1990 to February 1991 than from April 1991 to February 1992. The various metals were . distributed differently to the tissues of B. marequensis, with the highest zinc concentrations being accumulated by the skin and ovaries; the highest copper and iron by the liver, kidney and gut; the highest chromium and nickel by the blood; and the highest manganese, lead and strontium by the vertebrae and gills. These results afforded guidelines as to the types of tissue which should be sampled as the most suitable for the analysis of the various metals in polluted waters.

APA, Harvard, Vancouver, ISO, and other styles

39

Gagiano, Christopher Lodewyk. "An ecological study on the tigerfish hydrocynus vittatus in the olifants and letaba rivers with special reference to artificial reproduction." Thesis, 2012. http://hdl.handle.net/10210/7031.

Full text

Abstract:

M.Sc. Hydrocynus vittatus, commonly known as the tigerfish, plays an important role in riverine ecology. It is a top predator which roams the open waters of most larger river systems in southern Africa. Their presence in a freshwater ecosystem has a dramatic impact on the fish community structure. It is known that dams and weirs have a negative effect on the migration of the tigerfish. It is also evident that tigerfish do not occur in certain areas in some of the rivers where they have been present historically. The Olifants and Letaba Rivers in the Kruger National Park (KNP) are two of a few rivers within South Africa where tigerfish do occur. The KNP represents the edge of the most southern distribution of tigerfish in southern Africa. It was therefore expected that the tigerfish do not function optimal in the Olifants and Letaba Rivers as they are subjected to waters with high concentrations of silt and low flow which influences migration and successful breeding. Breeding migrations does however take place during the summer months after which the tigerfish returns to the Massingire Dam in Mozambique to avoid the colder winter temperatures in the rivers. Gonad development coincide with the yearly summer rainfall patterns. A deviation of the expected 1:1 male:female sex ratio to favour the males was experienced in both rivers, which may be the result of over population. Females were found to grow to a larger size than the males and were extremely fecund. Although H. vittatus is believed to be mainly piscivorous, other food items such as invertebrates, played an important role in the diet of small and large tigerfish in both the Olifants and Letaba Rivers. Invertebrates were mostly preyed upon which implies that optimal feeding conditions for the tigerfish does not prevail in these systems and that they have to adapt to satisfy their feeding requirements. Tigerfish is more abundant in the Olifants than in the Letaba River. The overall growth performance or phi prime (4)) values for H. vittatus in the Olifants River was determined and compares well to the overall growth performance of tigerfish in the Okavango River and Lake Kariba. However the maximum length calculated for tigerfish in the Olifants River (Lco = 52.40 cm ) is smaller than the Lco values (56.06 cm) for the Okavango River. The mortality rate of tigerfish in the Olifants River exceeds those in the Letaba River which means that the life expectancy is longer in the Letaba as opposed to the Olifants River. Successful artificial spawning revealed some of the secrets of the reproduction strategy of this species. Tigerfish has semi pelagic eggs, are very small (0.65 mm), negatively buoyant and slightly adhesive for bentic and epibiotic incubation, and it is expected that tigerfish would spawn in open water, on a sandy substrate in the vicinity of aquatic vegetation. First hatching took place at 22h 30 min after fertilization. Vertical movement of the larvae lasts for two days, which allows for downstream movement and dispersement of the larvae. It was found that tigerfish replace their teeth on a regular basis as they grow larger. Transition from conical to functional dentition takes place 45 days after hatching. Replacement of sets of teeth occurs during all phases of its lifespan. It is a quick proses of three to six days during which all teeth are replaced in both the upper and lower jaws.

APA, Harvard, Vancouver, ISO, and other styles

40

Swanepoel, D. G. J. "Movements, nesting and the effects of pollution on the Nile crocodile (Crocodylus niloticus) in the Olifants River, Kruger National Park." Thesis, 1999. http://hdl.handle.net/10413/10285.

Full text

Abstract:

A pilot study was launched in 1993 to determine the movements of crocodiles in the Olifants River in Kruger National Park (KNP). This turned into a research project in 1994 and lasted for five years until 1998. The objectives of the study were to determine movement, study nesting preferences and to investigate the possible effects of metal pollution in crocodiles. The movements of the total population were studied by doing regular foot counts, four times per annum. The basis for movement was found on the principle that a change in numbers signified movement. Foot counts were supported by spot counts at three different locations in the study area at 14 day intervals. The foot counts were done along a pre-determined route, followed with every count, and this resulted in data indicating a definite change in numbers at certain times of the year. A comparison was made between the movements of crocodiles in large bodies of open water (lakes & estuaries), a so called "closed" system and the Olifants River or "open" system. There was a movement of the population during August of every year, followed by another one in December/Jan and yet another in May. The largest movement, in August, co-coincided with the prelude to mating and ultimately nesting. The spot counts indicated that there was a smaller and probably localized movement during May and December of each year. This corresponds to nesting behaviour and the flood status of the river. All indications are that major movements took place during periods of high flow and thus during the rain season (Sept - Feb). A major flood was experienced during February 1996 which changed the geomorphology of the river. In addition to the foot and spot counts, eleven large adult crocodiles were fitted with radio transmitters to monitor their movements for a period of one year (1997 -1998). The results indicated that movements over large distances occurred. The longest distance covered was in access of 36 km. Some individuals returned to the location of origin, thus completing a round trip from their point of departure. The majority of crocodiles fitted with transmitters left the protection of KNP, spent time in neighbouring Mozambique and some returned to Kruger after an average period of three months. Indications are that there is a lack of territorial dominance amongst large individuals at certain times of the year, allowing for less restricted movement up and down the river. A difference was found between the movements of crocodiles in the Olifants River as opposed to a large body of water eg. a lake or estuary. The second objective was to collect data on nesting preference, nest content and egg dimensions. A total of seven parameters were measured including slope, distance to water, height above water, soil type, vegetation, exposure to direct sunlight and the size of the female. Besides these parameters, a comparison was made between egg size, mass and length and the correlation with female size. The results indicated that egg mass and length increased with an increase in female size. The average clutch size was 34 eggs. A difference was found between two nesting years (1997 and 1998) with the larger females nesting in 1998 (egg mass 122.7g). A higher rainfall was measured for 1998, leading to the conclusion that smaller females nested during dryer years. The larger females, because of physical abilities, dug deeper nests ,36 cm in 1998 as opposed to 25 cm in 1997. No difference was found between nesting habits elsewhere in Africa and that in the Olifants River. Twelve individuals of varying sizes ranging from 1.4 m to 4.1 m, were collected from three locations and various tissue samples were analysed for metal content. Tissue from muscle, liver, kidney and fat were analysed for Al, Cu, Cr, Fe, Mn, Ni, Pb, Section ranger and Zn. As this was the first data of its kind to be collected, no meaningful conclusions could be reached, except to offer the data as base line data and for future comparisons. There was however a correlation between Fe concentration in muscle tissue and body size, total length (TL). An increase in TL resulted in an increase in Fe concentration. The opposite were found with Fe in fat tissue. Smaller crocodiles (TL) had higher concentrations of Fe in their fat tissues. Besides the large amount of base line data that resulted from this study, it also highlighted the shortage of knowledge on this species, particularly in Kruger, to enable us to manage and protect them successfully. Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 1999.

APA, Harvard, Vancouver, ISO, and other styles

41

Mooney, Amanda. "An assessment of possible vitamin E deficiency in tigerfish (Hydrocynus vittatus) from the Olifants River in the Kruger National Park." Thesis, 2013. http://hdl.handle.net/10210/8564.

Full text

Abstract:

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.

APA, Harvard, Vancouver, ISO, and other styles

42

Nussey, Gail. "Metal ecotoxicology of the Upper Olifants River at selected localities and the effect of copper and zinc on fish blood physiology." Thesis, 2012. http://hdl.handle.net/10210/7393.

Full text

Abstract:

D.Phil. The entire Olifants . River Catchment is subjected to increasing afforestation, agricultural, domestic, mining, industrial, irrigation and urbanisation activities. These activities have a profound effect on the water quality of the river and its tributaries. This is cause for concern for the water users in the upper catchment, and because the Kruger National Park, one of its downstream water users, is extremely dependent on water of a satisfactory quality to sustain its various ecosystems. It is therefore vitally important to determine to what extent activities in the Upper Catchment of the Olifants River (Mpumalanga), especially in the Witbank and Middelburg areas, influence the water quality of the river. Point sources of pollution in the upper reaches include mining and industrial activities as well as water care works located at various points along the river. These were addressed in a Water Research Commission Project (No. 608/1/97) titled "Lethal and sublethal effects of metals on the physiology of fish: An experimental approach with monitoring support". Although sixteen localities were chosen for the initial project, this study only focussed around the metal ecotoxicology at two localities (Steenkool Spruit and Witbank Dam) in the upper catchment and the effect of metals (copper and zinc) on fish blood physiology. In aquatic ecosystems water quality is an important variable and full assessment of water quality, of Steenkool Spruit (locality 3) and Witbank Dam (locality 7), included evaluation of the chemical, physical and biological characteristics at each of the localities. Water and sediment samples were collected seasonally during the study period, February 1994 to May 1995, and the chemical and physical water quality variables were measured. During the study period three metal bioaccumulation indicator species, Labeo umbratus, Clarias gariepinus and Labeo capensis, were captured from which tissue (gills, liver, muscle and skin) samples were collected. These samples as well as water and sediment samples, were analysed for aluminium, chromium, copper, iron, manganese, nickel, lead and zinc concentrations, using atomic absorption spectrophotometry. In the past routine monitoring of chemical and physical water quality characteristics left scientists and managers with a sizeable pool of data which is often difficult but not impossible to interpret. To standardise and summarise this collection of data an aquatic toxicity index (ATI), WATER2 was developed by Wepener et at (1992). The present study attempted to expand and refine WATER2, which has resulted in the establishment of a new ATI, RAUWater.

APA, Harvard, Vancouver, ISO, and other styles

43

Brand, Mathilda E. "Bioaccumulation of metals in labeo congoro from the olifants river (Mpumalanga) and the effect of nickel on the haematology of fish." Thesis, 2008. http://hdl.handle.net/10210/822.

Full text

Abstract:

Water is one of the most important resources in South Africa. The increased pressure on river systems in SA as a result of human activities and industrial development is evident from the systematic deterioration of the Olifants River (Mpumalanga). While the number of water users grows daily, the river is seen as a convenient disposal site. It is necessary to continually monitor the river to be aware of its status. Regular monitoring also supplements the existing data on water quality, biotic communities and possible points of pollution. The study had the following aims: Firstly to contribute to a larger project on the effect of pollutants on the physiology of fish populations in the Olifants River. This study concentrates on the bioaccumulation of certain metals (i.e. chromium, copper, iron, manganese, nickel, lead, strontium and zinc), in the gills, liver and muscle of Labeo congoro. Standard methods were used to prepare the organs and tissues for metal analysis using atomic absorption spectrophotometry. The following conclusions were reached subsequent to statistical analysis of the results: • The highest mean concentrations of all metals were recorded in the liver of Labeo congoro. • The lowest mean metal concentrations were calculated in the muscle, except for chromium, the concentrations of which were the lowest in the gills. • The highest mean concentration of each metal was recorded in organs / tissues of fish sampled at locality 2. • None of the three localities can be singled out to indicate the lowest mean concentration of each metal. Summary iii The second aim of this study was to determine the 96-hr LC50 (lethal concentration at which 50% of the test population dies) of nickel. Oreochromis mossambicus was used as test organisms for these laboratory studies. A flow through system was used to ensure that the organisms were exposed to the same concentration of nickel for 96 hours. Subsequent to the 96-hr LC50 determination, test organisms were subjected to sublethal exposure of nickel to determine the effects of the various concentrations of the haematology and blood coagulation processes of fish. The following conclusions were drawn from the statistical data processing: • The 96-hr LC50 of nickel for Oreochromis mossambicus is 50 μg.l-1. • The exposure to sublethal concentrations of nickel did effect certain haematological variables • No statistically significant differences in the blood coagulation variables at different sublethal concentrations of nickel were confirmed The results of this study can be used to supplement the database on the water quality and general status of the Olifants River (Mpumalanga). The LC50 of nickel can be used as one of the variables in water quality studies. Prof. Johan van Vuren

APA, Harvard, Vancouver, ISO, and other styles

44

Van, der Merwe Marinda. "Aspects of heavy metal concentration in the Olifants River, Kruger National Park and the effect of copper on the haematology of Clarias gariepinus (Clariidae)." Thesis, 2014. http://hdl.handle.net/10210/9327.

Full text

Abstract:

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.

APA, Harvard, Vancouver, ISO, and other styles

45

Robinson, Jenny. "Evaluation of a health assessment index with reference to bioaccumulation of metals in Oreochromis mossambicus (Peters, 1852) and aspects of the morphology of Lernaea cyprinacea, Linnaeus, 1758." Thesis, 2014. http://hdl.handle.net/10210/12845.

Full text

APA, Harvard, Vancouver, ISO, and other styles

46

Barnhoorn, Irene Ellen Jane. "Effects of manganese on the haematology of Oreochromis mossambicus and the bioaccumulation of metals in Labeo umbratus." Thesis, 2012. http://hdl.handle.net/10210/6928.

Full text

Abstract:

M.Sc. Metal ions have become an increasing source of pollution in the natural waters of South Africa. This phenomenon is related to the rapid industrial, mining and agricultural activity growth along rivers, especially in the Upper catchment of the Olifants River, Mpumalanga. In general, metal ions have - negative effects on the physiology of fish and other aquatic biota in metal polluted waters. In this study. the sublethal effects of, manganese were determined by exposing the freshwater fish, Oreochromis mossambicus, to this metal in an experimental flow-through system. The exposure times were divided in acute (96 hours) and chronic (26 days) exposures, both at 23 ± 1°C. The results obtained showed changes in the general, haematological, metabolic, osmoregulatory variables, as well as the differential white blood cell counts. These changes indicated several effects in the physiology of a mossainblais after sublethal manganese exposure. Significant differences (P < 0.05) were found between the haematological variables of the control and exposed fish. During chronic exposure, an oxygen deficiency developed due to , the epithelial lifting of gill lamellae. As a result of hypoxia the red blood cell numbers, haemoglobin-, haematocrit and lactate concentrations increased to uplift the depleted oxygen situation. The significant differences (P < 0.05) found in the sodium, potassium,. calcium and chloride concentrations are mainly as a result of gill damage. Manganese showed a disruptive influence on the structural organization of the gill. The differential white blood cell counts performed , showed significant fluctuations. This leucocytosis and leucopenia are normal reactions of the fishes’ body against infections of foreign substances, such as metal ions. It was concluded that the general haematology, metabolism, osmoregulation and differential white blood cell counts can, be used as indicators in detecting the effects of sublethal manganese exposure on fish.

APA, Harvard, Vancouver, ISO, and other styles

47

Van, Gessellen Annemarie. "The presence of persistent organic pollutants and heavy metals in sediment samples from rivers in the Kruger National Park / Annemarie van Gessellen." Thesis, 2015. http://hdl.handle.net/10394/15685.

Full text

Abstract:

Since 2008, large numbers of Nile crocodile (Crocodylus niloticus) carcasses were found in the Kruger National Park (KNP), South Africa. Most of the crocodile carcasses were found in the Olifants Gorge, which is situated below the Letaba and Olifants river confluence, before the Mozambique border and Massingir Dam. The Massingir Dam is an important resource and it plays a significant role in the welfare of the local Mozambican population. Autopsies performed on the crocodiles indicated that the adipose tissue colour changed from normal white to yellow and this is usually a sign of pansteatitis. Pansteatitis is caused by lipid peroxidation in an organism and it is characterised by the lack of vitamin E. This disease is recognisable by the hardening of the fatty tissue and yellow discolouration, and is mostly associated with aquatic organisms from polluted ecosystems. There are speculations that the crocodile fatalities may be associated with the Massingir Dam that backed up into the Olifants Gorge after flooding. After the dam was reconstructed, it flooded the Olifants Gorge, causing it to act like a localised sediment trap as the water flow slowed down and as a result, caused pollutants to build-up. Sediment samples were collected from selected rivers and ponds within the KNP. These samples were analysed for selected elements, persistent organic pollutants (POPs), and polycyclic aromatic hydrocarbons (PAHs). The sediment samples were analysed in Norway for POPs and PAHs with the use of a high-resolution gas chromatography/mass spectrometry (GC/MS) and the heavy metals were analysed in South Africa with the use of inductively-coupled plasma mass spectrometry (ICP/MS). In order to identify which elements may have affected the health of the crocodiles, a series of sediment quality indices were used. These indices made it possible to determine which elements may have been involved. The order of probability of heavy metals causing harm was Se>As>Ni>Cr>Cu>I>V>Mn>Co>Fe>Cd>Hg>Zn>Pb>Ba>U. The data was compared to selected international guidelines. All the information was used to determine which of the sampled sites had the highest contamination. The sites sampled with the highest concentrations were in the Crocodile, Nkomati, Olifants, and Letaba Rivers. Concentrations of the elements, POPs, and PAHs were also quantifiable in the Olifants Gorge. The following elements (Fe, Co, Cu, Cr, Pb, V, As, and Ni) were quantified at elevated levels and may therefore have caused negative effects on the crocodiles in the Olifants Gorge. These elevated concentrations, in combination with the dramatic change in the physical environment due to the dam, could have added additional stress that may have contributed to the observed crocodile mortalities in the Olifants Gorge. MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2015

APA, Harvard, Vancouver, ISO, and other styles

48

Madanire-Moyo, Grace Nyepai. "A comparative evaluation of ecosystem health of selected water bodies in the Olifants and Limpopo River systems using the health assessment index and parasite diversity as indicators." Thesis, 2011. http://hdl.handle.net/10386/438.

Full text

Abstract:

Thesis (Ph.D. (Zoology)) --University of Limpopo (Turfloop Campus), 2011 South Africa's water resources are limited and scarce in global terms, due to the fact that the country's climate varies from desert to semi-desert in the west to sub-humid along the coastal area. The country is also expected to experience further variability in rainfall, reduced precipitation and increased evaporation as a result of climate change. At the projected population growth and economic development rates, it is unlikely that the projected demand on water resources in South Africa will be sustainable. An additional concern is the declining water quality due to domestic, mining and industrial pollution, and eutrophication as well as salinisation due to agricultural pollution. Thus, aquatic ecosystems must be protected, monitored and managed to ensure sustainable resource use. The aim of the study was to evaluate and compare possible environmental deterioration by analysing fish health and parasite diversity in three dams within the Limpopo and Olifants River Systems by using the fish Health Assessment Index (HAI) and the Inverted Parasite Index (IPI). The intention of the study was to substantiate the theories behind the HAI and IPI in a bid to augment strategies to manage water quality, fish health and aquatic biodiversity. Seasonal surveys were carried out between April 2008 and April 2010 at three localities. The Luphephe-Nwanedi Dams are in a Nature Reserve located in a rural catchment, the Flag Boshielo Dam in an industrualised and mining catchment whereas the Return Water Dam is located on a platinum mining premise. Clarias gariepinus (Burchell, 1822) and Oreochromis mossambicus (Peters, 1852) were collected with the aid of gill nets and used as indicator fish species. Fish were examined for external parasites after which they were weighed and measured. Blood was drawn and skin smears were made. The skin smears were examined with a dissecting microscope for the presence of parasites. Fish were killed, dissected and then examined as prescribed in the fish HAI. From the ecto- and endoparasite data collected, infection statistics and ecological parameters were calculated. The HAI values were calculated for each fish species at each sampling site. To verify the results of the HAI, water quality was included in the studyThe nutrients and mining related pollutants of the three dams differed to a great extent and showed a similar increasing trend in the order: Luphephe-Nwanedi Dams < Flag Boshielo Dam < Return water Dam. Our results were consistent with previous work describing Luphephe-Nwanedi Dams as essentially unimpacted and Flag Boshielo Dam as impacted with a combination of mining and agricultural effluents. The results have shown that the Return Water Dam is an extremely polluted site with high levels of nutrients and metals. Fish health of both species responded similarly to polluted sites although mean population HAI results showed that C. gariepinus was more affected in terms of haematocrit necropsy-related alterations. The top six metrics that correlated most to fish health scores were nearly the same for both species (i.e. haematocrit values, inverted ectoparasite index, condition of the kidney, liver, gills and skin). The parasite community of C. gariepinus comprised 19 metazoan species. Seventeen parasite species were recovered from fish sampled from Luphephe-Nwanedi Dams compared to 11 at Flag Boshielo Dam and four at the Return Water Dam. The parasite community of O. mossambicus comprised 20 metazoan species. A total of 19 species, 17 species, and 4 species of metazoan parasites from O. mossambicus were obtained from Luphephe-Nwanedi Dams, Flag Boshielo Dam and the Return Water Dam, respectively. In both fish species, the Shannon Wiener Index, the inverse Simpson Index, equitability and the number of metazoan parasite individuals were highest in fish from Luphephe-Nwanedi Dams. The results of this study emphasized the negative impacts of urbanization, agricultural and mining activities on the environment. The fish hosts collected in the mining premise supported the poorest and least diverse parasite communities of all sampled sites, with virtual depletion of both heteroxenous and monoxenous species. The Return Water Dam may therefore be regarded as a simulation model for a severely environmentally deteriorated, impoverished habitat, in which all or part of the intermediate hosts have been depleted, enabling the survival of hardy parasite species only. Further studies should address the identification of parasite life stages that are more sensitive to pollutants The National Research Foundation,the Flemish Interuniversity Council(VLIR-UOS),and the Division for Research Administration and Development,University of Limpopo

APA, Harvard, Vancouver, ISO, and other styles

49

Ramollo, Phetole Peter. "Bioassessing the impact of water quality on the health and parasite composition of Oreochromis Mossambicus at the Phalaborwa Industrial Complex (PIC) and the barrage (Olifants river) in the Limpopo Province,South Africa." Thesis, 2008. http://hdl.handle.net/10386/366.

Full text

Abstract:

Thesis (M.Sc)--University of Limpopo, 2008. Three sites at the Phalaborwa Industrial Complex (PIC) and one site at the Phalaborwa Barrage in the Olifants River were selected to illustrate the possible influence of different water quality parameters on the health and parasite composition of the Mozambique tilapia (Oreochromis mossambicus). Ten fish were collected seasonally at each site using gill nets of different mesh sizes. Selected water quality variables were determined at all the sites to establish possible differences in water quality between the sites. Hosts were examined for mobile ectoparasites, weighed and measured. Blood samples were drawn and skin smears were made. Fish were killed, dissected and all external and internal organs were examined as prescribed in the fish health assessment index (HAI). The condition factor was determined for each fish population from the different sites. All parasites were collected, fixed and preserved using standard methods. A parasite index(PI), abundance, prevalence and mean intensity of the parasite infestations were calculated.Results obtained for the system variables (pH, water temperature and dissolved oxygen) indicated that the pH levels and water temperature fell within the target water quality range (TWQR) for aquatic ecosystems, but the dissolved oxygen recorded during most of the surveys were below 5mg O2 l-1 which may adversely affect the functioning and survival of biological communities. The mean turbidity values were high at sites A, C and D (caused by fine particles such as silt, clay and organic matter). The total dissolved solids (TDS) and the electrical conductivity (EC) were very high at sites B and C throughout the study. The total water hardness and salinity were also very high at sites B and C which can be attributed to the mine tailings water as well as the geology of the region. The cations (calcium, magnesium and potassium) and anions (chloride, fluoride and sulphate) were above the TWQR for aquatic ecosystems at all sites. The fluoride and sodium levels were high at sites B and C. All the major ions contributed significantly to increased levels of TDS, salinity and EC at sites B and C. The nitrogen and phosphate levels indicated that there was an influx of nutrients into the four sampling sites at varying degrees, which can have an effect on eutrophication conditions at the sampling sites. Trace and heavy metal concentrations differed significantly between all the sites. Aluminium, iron and manganese levels were within the TWQR for aquatic ecosystems at all sites. Copper, lead and zinc levels were above the TWQR and sometimes above the chronic and acute effect values for aquatic ecosystems throughout the study (except for lead concentrations at site A). Thus, the mining activities do affect the water quality at sites B and C adversely in terms of the dissolved salts, nutrients and trace and heavy metals (with the water at site C more impacted than that of site B). The toxicity of some metals is however, dependant on the pH (if it changes to be more acidic, some metals may become toxic) and water hardness of the specific site. The lowest population HAI values (indicating healthier fish populations) were mostly recorded from sites A and D (the sites with better water quality) and the highest at site C(the site with poorer water quality) for three surveys. The high HAI values at site C can mainly be attributed to liver discoloration and abnormal haematological parameters. The fish condition factor values ranged from 0.92 to 1.2 with the lowest mean value recorded at site A and the highest mean value recorded at site B. But, the condition factors indicated that the fish from all sites were generally in good health. The values attained for the haematological parameters, liver discolorations, fins (due to parasitic infestation),abnormal gills, as well as the type of parasites present in/on the fish, were the most indicative parameters in the HAI. No abnormalities in the kidneys, opercules and spleens of fish were observed at any of the four sampling sites during this study. Results from the HAI thus indicated that the fish population from site C was more affected by the water quality (with a higher HAI) compared to the fish populations from the other sites. Also, dissimilar water quality at the different sites affected the health of fish differently. The results recorded for the HAI of the different fish populations thus substantiate the results obtained from the water analysis, indicating that fish from site C (with the poorest water quality) was more affected by their environment. The parasites recorded from O. mossambicus were all site-specific and seem to be moderately influenced by the water quality of the different sites. Some groups, e.g. monogeneans were more affected by the differences in water quality than other parasitic groups. The following ectoparasites were recorded: Cichlidogyrus sp. from the gills and Lernaea cyprinacea and Argulus japonicus from the skin. Endoparasites included digenean larvae from the skin (“black spot”) and gills, Neutraclinostomum larvae in the branchial region, Diplostomum metacercariae from the eyes and swimbladder,Diplostomum tregenna from the brain, dilepidid cestode larvae from the liver and outer surface of the intestine, Contracaecum larvae from the body cavity and sinus venosus of the heart, adult acanthocephalans from the intestine, and pentastomatid larvae of two genera (Subtriquetra rileyi and Alofia sp.) from the swimbladder. The hypothesis that the number of ectoparasites will be lower in more polluted water and the number of endoparasites will be higher was well supported for O. mossambicus at all sites except at site C during Spring survey. The PI for endoparasites was higher at all the mine sites (except during Spring) but similar results were also obtained at sites A and D (the less impacted sites). However, all sites tested during this study were impacted to a lesser or higher degree and the PI for endoparasites can thus be higher at all sites. Some ectoparasites (i.e. Lernaea cyprinacea) were present in high numbers at the more polluted site (site C), but the abundance of monogeneans (also ectoparasites) was most of the time lower at sites B and C, suggesting that monogeneans have been strongly influenced by the poorer water quality at these sites. The specific water parameter/s that influenced the abundance of certain ectoparasites needs further investigation which would most probably best be tested under controlled laboratory conditions. In conclusion, all sites sampled during this study were contaminated to some degree with sites B and C more impacted than the other two sites. The water quality results thus confirmed the results obtained using the HAI and to a lesser extent, the PI. The water quality differed between the four sites and had dissimilar impacts on the health of O. mossambicus and the prevalence of some parasites at the different sites. the National Research Foundation,the Sasol Nitro

APA, Harvard, Vancouver, ISO, and other styles

50

Marx, Hazel Mary. "Evaluation of a health assessment index with reference to metal bioaccumulation in Clarias gariepinus and aspects of the biology of the parasite Lamproglena clariae." Thesis, 2012. http://hdl.handle.net/10210/5703.

Full text

Abstract:

M.Sc. The catchment area of the Olifants River has, over a number of years, been exposed to extensive mining, agriculture and urbanisation activities in the Witbank-Middelburg and Phalaborwa regions which has largely contributed to the deterioration of water quality. Of major concern is the influence anthropogenic activities have on the aquatic ecosystem of the Olifants River within the Kruger National Park and how me health of fish residing In these waters is affected. To determine fish health, a biological monitoring method, the Health Assessment Index (H41), was tested for the first time In South Africa. Four surveys were conducted at Mamba and Balule In the Olifants River, Kruger National Park during 1994 (February, May, July and November). An additional survey was conducted in February 1995 at Loskop Dam. Samples of water and sediment were taken for analysis of metals and physical and chemical water parameters. A maximum of 20 Clarias gariepinus fish were sampled at each location. Evaluation of the fish was done according to guidelines set in the HAI and parasite population composition (prevalence, abundance, mean intensity) was determined. Organ and tissue samples including gills, liver, muscle and skin were analysed for the bioaccumulation of chromium, copper, Iron, manganese, nickel, lead, strontium and zinc, using atomic absorption spectrophotomeby. Metal concentrations in the water at Mamba and Balule were within guideline limits, whereas concentrations at Loskop Dam were above guidelines. As reflected by the application of the Aquatic toxicity Index, Loskop Dam presented with the poorest water quality followed by Mamba then Balule. It was found that certain physical and chemical variables namely fluoride, potassium, sulphate and total dissolved solids concentrations at Mamba and Balule were relatively high, particularly during drier months. Metals accumulated in organs and tissues, with the highest concentrations In the gills followed by the liver, skin and muscle. The discriminant analysis, utilising metal bloaccumulation, discriminates between water quality at Mamba and Balule, revealing a 100 % classification probability for each survey. Values obtained In the application of the HAI indicated that variables with good predictor accuracy were plasma protein, all parasites, endoparasites, liver, white blood cell counts, ectoparasites, skin, fins and gills. The discriminant function for the HAI generally Indicated variables similar to those exhibiting high predictor accuracy. The discriminant function showed relatively low classification probability for each survey. In case 1, where separate endo- and ectoparasite variables were Included in the determination of me discriminant function, probability for me entire study ranged between 47.5 % and 84.2 %. In case 2, where endo- and ectoparasite variables were given a refined score rating system, probability ranged between 62.5 % and 100 %. The low classification probability Indicates either the Importance of repetitive testing for this technique or a total departure from it. Results showed that fish populations with higher HAI values are found in water of poorer quality (Mamba), while healthier fish populations i.e. with lower RAI values are found In water of better quality (Balule). Parasite data shows a similar tendency by indicating that ectoparasites are abundant in water of higher quality, while endoparasftes increase in water of poorer quality. The HAI reflects the condition of fish populations in relation to their aquatic environment, therefore, the HA/ gives an indication of water quality and should be used as a first level screening tool. If complemented by a parasite survey, distinguishing between endoand ectoparasites, the results from the HAI will be enhanced.

APA, Harvard, Vancouver, ISO, and other styles

Dissertations / Theses on the topic 'Olifants River'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles