Introduction: Water quality assessment is a fundamental requirement for comprehensive water manag... more Introduction: Water quality assessment is a fundamental requirement for comprehensive water management. Access to water is not exclusively a quantitative issue, as human activities often lead to negative impacts on water quality due to pollution. This results in a need for the systematic monitoring of water bodies to surveil ongoing pollution dynamics and, if needed, facilitate the implementation of suitable solutions for water quality management. Methods: To that eect, in March 2022 and July 2023, we conducted two sampling campaigns in four headwater streams in QwaQwa, South Africa, to assess the water quality under high (summer) and low (winter) flow conditions. The overarching aim was to support local decision-makers with relevant information on water quality in a semirural and less studied area. Beside the hydrological characterization of the catchment, which drains the mountainous areas around Phuthaditjhaba (the main town of the region), physicochemical and biological monitoring were conducted, including in vitro tests detecting endocrine disruption, dioxin-like impacts, and genotoxic potentials in the water. Results: The elemental analysis showed that at several sampling sites, Al, Cu, Mn, Fe, and Zn were above the Target-Water-Quality-Range (TWQR) for aquatic ecosystems and Fe, Al, and Mn were additionally above the TWQR for domestic use. Interestingly, the organic micropollutants (OMPs) revealed a region with a high incidence of HIV infections, given the occurrence of the drugs efavirenz, its transformation product 8-OH-efavirenz and nevirapine, among other micropollutants. Possibly, the signals from the in vitro tests for endocrine disruption are also induced by the detected micropollutants. Our results ultimately show that even though anthropogenic impacts increase from upstream to downstream, none of the sampling sites are without concern. This indicates the urgent need for measures to increase the water quality of these headwater streams in this region
The main aims of this study was to investigate hydraulic fracturing by performing a background re... more The main aims of this study was to investigate hydraulic fracturing by performing a background review; developing an interactive vulnerability map; and developing a provisional screening level monitoring protocol. This study aimed to contribute knowledge on issues associated with hydraulic fracturing and highlight vulnerable areas for specific aspects in South Africa. It also proposes a provisional screening level monitoring protocol that can be used as a guideline to monitor unconventional gas extraction activities. In South Africa, where water demand will exceed water supply in the near future, unsustainable use of water resources will result in increasingly limited water resources for future health and well-being as well as for sustained socio-economic development. Society in general, and specifically the residents in the Karoo where access to water is already limited, needs to be assured of the sustainable use of the water resources for health and well-being by understanding and...
Various biophysical and socio-economic impacts may be associated with unconventional oil and gas ... more Various biophysical and socio-economic impacts may be associated with unconventional oil and gas (UOG) extraction. A vulnerability map may assist governments during environmental assessments, spatial planning and the regulation of UOG extraction, as well as decision-making around UOG extraction in fragile areas. A regional interactive vulnerability map was developed for UOG extraction in South Africa. This map covers groundwater, surface water, vegetation, socio-economics and seismicity as mapping themes, based on impacts that may emanate from UOG extraction. The mapping themes were developed using a normative approach, where expert input during the identification and classification of vulnerability indicators may increase the acceptability of the resultant map. This article describes the development of the interactive vulnerability map for South Africa, where UOG extraction is not yet allowed and where regulations are still being developed to manage this activity. The importance an...
The 2nd African Water Symposium, in conjunction with the 6th Orange River Basin Symposium, was he... more The 2nd African Water Symposium, in conjunction with the 6th Orange River Basin Symposium, was held on the campus of the University of the Free State, Bloemfontein, on 7 and 8 October 2015. The theme of the symposium was 'systems thinking in environmental water resources management', with the aim of evaluating and debating a holistic approach to water management in southern Africa. The symposium included a panel discussion that was originally intended to define a roadmap towards effective water resources management, but it soon took on a life of its own and evolved into a discussion on how to develop and train the next generation of managers and scientists to tackle the current challenges being faced by the wider water sector. This commentary serves as a record of the main themes identified during the panel discussion and begins by setting the South African context and identifying the plurality of values and opinions held by stakeholders in the post-apartheid water sector. I...
South African Journal of Wildlife Research - 24-month delayed open access, 1994
Analysis of scats of Cape clawless otters Aonyx capensis from the Kingna River, a tributary of th... more Analysis of scats of Cape clawless otters Aonyx capensis from the Kingna River, a tributary of the Breede River, shows that throughout the year mainly freshwater crabs Potamonautes ct. perlatus are eaten. Insects and mammals are next in importance as prey, followed by fish, but few frogs are taken. Misanalises van otters in die Kingna-rivier, 'n sytak van die Breerivier, toon dat hulle hoofprooi dwarsdeur die jaar hoofsaaklik uit varswaterkrappe Potamonautes ct. perlatus bestaan. Volgende in belangrikheid is insekte en soogdiere, dan visse, maar min paddas word gevreet.
Various biophysical and socio-economic impacts may be associated with unconventional oil and gas ... more Various biophysical and socio-economic impacts may be associated with unconventional oil and gas (UOG) extraction. A vulnerability map may assist governments during environmental assessments, spatial planning and the regulation of UOG extraction, as well as decision-making around UOG extraction in fragile areas. A regional interactive vulnerability map was developed for UOG extraction in South Africa. This map covers groundwater, surface water, vegetation, socio-economics and seismicity as mapping themes, based on impacts that may emanate from UOG extraction. The mapping themes were developed using a normative approach, where expert input during the identification and classification of vulnerability indicators may increase the acceptability of the resultant map. This article describes the development of the interactive vulnerability map for South Africa, where UOG extraction is not yet allowed and where regulations are still being developed to manage this activity. The importance an...
The main aims of this study was to investigate hydraulic fracturing by performing a background re... more The main aims of this study was to investigate hydraulic fracturing by performing a background review; developing an interactive vulnerability map; and developing a provisional screening level monitoring protocol. This study aimed to contribute knowledge on issues associated with hydraulic fracturing and highlight vulnerable areas for specific aspects in South Africa. It also proposes a provisional screening level monitoring protocol that can be used as a guideline to monitor unconventional gas extraction activities. In South Africa, where water demand will exceed water supply in the near future, unsustainable use of water resources will result in increasingly limited water resources for future health and well-being as well as for sustained socio-economic development. Society in general, and specifically the residents in the Karoo where access to water is already limited, needs to be assured of the sustainable use of the water resources for health and well-being by understanding and...
A large percentage of southern African rivers is non-perennial - mainly as result of the highly v... more A large percentage of southern African rivers is non-perennial - mainly as result of the highly variable and unpredictable climate experienced over much of the region. These rivers are primarily distinguished by their spatially and temporally variable hydrological regimes and by the loss of surface water connectivity when flow periodically fails - confining surface water to isolated pools. With the climate expected to become increasingly warmer, drier and even more variable over large parts of southern Africa, pressure to provide freshwater with an acceptable degree of assurance is expected to increase. The South African National Water Act requires that an environmental reserve be determined for each significant water body before water-use licenses are issued. Previous studies have shown that methods used to determine the environmental water requirements for perennial rivers are not ideally suited for non-perennial rivers with their specific challenges. This paper proposes a new pro...
Nearly half of South Africa’s rivers is temporary – a function of the semi-arid/arid climate prev... more Nearly half of South Africa’s rivers is temporary – a function of the semi-arid/arid climate prevailing over much of the region. Temporary rivers are distinguished by highly variable and unpredictable hydrological regimes, large disturbances and the loss of surface water connectivity - confining surface water to isolated pools. Instream water requirement (IWR) assessments developed for perennial rivers are poorly equipted to deal with these factors and have been adapted for use in South Africa’s temporary rivers. The newly developed IWR-method (Seaman et al., 2010) uses several driving (e.g. hydrological) and responding (e.g. fish) indicators to predict ecological and socio-economic impacts to hydrological changes. Even though terrestrial vertebrates’ life histories are known to be significantly affected by hydrological changes, the inclusion of mammals as indicators have been largely neglected. This contribution considers the viability of incorporating otters and water mongoose int...
The South African National Water Act requires that an environmental reserve be determined for eac... more The South African National Water Act requires that an environmental reserve be determined for each significant water body before water-use licenses may be issued. Methods currently available for the determination of environmental water requirements in South Africa are based on perennial rivers and are seen as needing verification for use on non-perennial systems.
Introduction: Water quality assessment is a fundamental requirement for comprehensive water manag... more Introduction: Water quality assessment is a fundamental requirement for comprehensive water management. Access to water is not exclusively a quantitative issue, as human activities often lead to negative impacts on water quality due to pollution. This results in a need for the systematic monitoring of water bodies to surveil ongoing pollution dynamics and, if needed, facilitate the implementation of suitable solutions for water quality management. Methods: To that eect, in March 2022 and July 2023, we conducted two sampling campaigns in four headwater streams in QwaQwa, South Africa, to assess the water quality under high (summer) and low (winter) flow conditions. The overarching aim was to support local decision-makers with relevant information on water quality in a semirural and less studied area. Beside the hydrological characterization of the catchment, which drains the mountainous areas around Phuthaditjhaba (the main town of the region), physicochemical and biological monitoring were conducted, including in vitro tests detecting endocrine disruption, dioxin-like impacts, and genotoxic potentials in the water. Results: The elemental analysis showed that at several sampling sites, Al, Cu, Mn, Fe, and Zn were above the Target-Water-Quality-Range (TWQR) for aquatic ecosystems and Fe, Al, and Mn were additionally above the TWQR for domestic use. Interestingly, the organic micropollutants (OMPs) revealed a region with a high incidence of HIV infections, given the occurrence of the drugs efavirenz, its transformation product 8-OH-efavirenz and nevirapine, among other micropollutants. Possibly, the signals from the in vitro tests for endocrine disruption are also induced by the detected micropollutants. Our results ultimately show that even though anthropogenic impacts increase from upstream to downstream, none of the sampling sites are without concern. This indicates the urgent need for measures to increase the water quality of these headwater streams in this region
The main aims of this study was to investigate hydraulic fracturing by performing a background re... more The main aims of this study was to investigate hydraulic fracturing by performing a background review; developing an interactive vulnerability map; and developing a provisional screening level monitoring protocol. This study aimed to contribute knowledge on issues associated with hydraulic fracturing and highlight vulnerable areas for specific aspects in South Africa. It also proposes a provisional screening level monitoring protocol that can be used as a guideline to monitor unconventional gas extraction activities. In South Africa, where water demand will exceed water supply in the near future, unsustainable use of water resources will result in increasingly limited water resources for future health and well-being as well as for sustained socio-economic development. Society in general, and specifically the residents in the Karoo where access to water is already limited, needs to be assured of the sustainable use of the water resources for health and well-being by understanding and...
Various biophysical and socio-economic impacts may be associated with unconventional oil and gas ... more Various biophysical and socio-economic impacts may be associated with unconventional oil and gas (UOG) extraction. A vulnerability map may assist governments during environmental assessments, spatial planning and the regulation of UOG extraction, as well as decision-making around UOG extraction in fragile areas. A regional interactive vulnerability map was developed for UOG extraction in South Africa. This map covers groundwater, surface water, vegetation, socio-economics and seismicity as mapping themes, based on impacts that may emanate from UOG extraction. The mapping themes were developed using a normative approach, where expert input during the identification and classification of vulnerability indicators may increase the acceptability of the resultant map. This article describes the development of the interactive vulnerability map for South Africa, where UOG extraction is not yet allowed and where regulations are still being developed to manage this activity. The importance an...
The 2nd African Water Symposium, in conjunction with the 6th Orange River Basin Symposium, was he... more The 2nd African Water Symposium, in conjunction with the 6th Orange River Basin Symposium, was held on the campus of the University of the Free State, Bloemfontein, on 7 and 8 October 2015. The theme of the symposium was 'systems thinking in environmental water resources management', with the aim of evaluating and debating a holistic approach to water management in southern Africa. The symposium included a panel discussion that was originally intended to define a roadmap towards effective water resources management, but it soon took on a life of its own and evolved into a discussion on how to develop and train the next generation of managers and scientists to tackle the current challenges being faced by the wider water sector. This commentary serves as a record of the main themes identified during the panel discussion and begins by setting the South African context and identifying the plurality of values and opinions held by stakeholders in the post-apartheid water sector. I...
South African Journal of Wildlife Research - 24-month delayed open access, 1994
Analysis of scats of Cape clawless otters Aonyx capensis from the Kingna River, a tributary of th... more Analysis of scats of Cape clawless otters Aonyx capensis from the Kingna River, a tributary of the Breede River, shows that throughout the year mainly freshwater crabs Potamonautes ct. perlatus are eaten. Insects and mammals are next in importance as prey, followed by fish, but few frogs are taken. Misanalises van otters in die Kingna-rivier, 'n sytak van die Breerivier, toon dat hulle hoofprooi dwarsdeur die jaar hoofsaaklik uit varswaterkrappe Potamonautes ct. perlatus bestaan. Volgende in belangrikheid is insekte en soogdiere, dan visse, maar min paddas word gevreet.
Various biophysical and socio-economic impacts may be associated with unconventional oil and gas ... more Various biophysical and socio-economic impacts may be associated with unconventional oil and gas (UOG) extraction. A vulnerability map may assist governments during environmental assessments, spatial planning and the regulation of UOG extraction, as well as decision-making around UOG extraction in fragile areas. A regional interactive vulnerability map was developed for UOG extraction in South Africa. This map covers groundwater, surface water, vegetation, socio-economics and seismicity as mapping themes, based on impacts that may emanate from UOG extraction. The mapping themes were developed using a normative approach, where expert input during the identification and classification of vulnerability indicators may increase the acceptability of the resultant map. This article describes the development of the interactive vulnerability map for South Africa, where UOG extraction is not yet allowed and where regulations are still being developed to manage this activity. The importance an...
The main aims of this study was to investigate hydraulic fracturing by performing a background re... more The main aims of this study was to investigate hydraulic fracturing by performing a background review; developing an interactive vulnerability map; and developing a provisional screening level monitoring protocol. This study aimed to contribute knowledge on issues associated with hydraulic fracturing and highlight vulnerable areas for specific aspects in South Africa. It also proposes a provisional screening level monitoring protocol that can be used as a guideline to monitor unconventional gas extraction activities. In South Africa, where water demand will exceed water supply in the near future, unsustainable use of water resources will result in increasingly limited water resources for future health and well-being as well as for sustained socio-economic development. Society in general, and specifically the residents in the Karoo where access to water is already limited, needs to be assured of the sustainable use of the water resources for health and well-being by understanding and...
A large percentage of southern African rivers is non-perennial - mainly as result of the highly v... more A large percentage of southern African rivers is non-perennial - mainly as result of the highly variable and unpredictable climate experienced over much of the region. These rivers are primarily distinguished by their spatially and temporally variable hydrological regimes and by the loss of surface water connectivity when flow periodically fails - confining surface water to isolated pools. With the climate expected to become increasingly warmer, drier and even more variable over large parts of southern Africa, pressure to provide freshwater with an acceptable degree of assurance is expected to increase. The South African National Water Act requires that an environmental reserve be determined for each significant water body before water-use licenses are issued. Previous studies have shown that methods used to determine the environmental water requirements for perennial rivers are not ideally suited for non-perennial rivers with their specific challenges. This paper proposes a new pro...
Nearly half of South Africa’s rivers is temporary – a function of the semi-arid/arid climate prev... more Nearly half of South Africa’s rivers is temporary – a function of the semi-arid/arid climate prevailing over much of the region. Temporary rivers are distinguished by highly variable and unpredictable hydrological regimes, large disturbances and the loss of surface water connectivity - confining surface water to isolated pools. Instream water requirement (IWR) assessments developed for perennial rivers are poorly equipted to deal with these factors and have been adapted for use in South Africa’s temporary rivers. The newly developed IWR-method (Seaman et al., 2010) uses several driving (e.g. hydrological) and responding (e.g. fish) indicators to predict ecological and socio-economic impacts to hydrological changes. Even though terrestrial vertebrates’ life histories are known to be significantly affected by hydrological changes, the inclusion of mammals as indicators have been largely neglected. This contribution considers the viability of incorporating otters and water mongoose int...
The South African National Water Act requires that an environmental reserve be determined for eac... more The South African National Water Act requires that an environmental reserve be determined for each significant water body before water-use licenses may be issued. Methods currently available for the determination of environmental water requirements in South Africa are based on perennial rivers and are seen as needing verification for use on non-perennial systems.
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Papers by Marinda Avenant