Evaluating The Potential Contribution Of Episodic Toxicity Data To Environmental Water Quality Management In South Africa
- Gordon, Andrew K, Mantel, Sukhmani K, Muller, Nikite W J
- Authors: Gordon, Andrew K , Mantel, Sukhmani K , Muller, Nikite W J
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , report
- Identifier: http://hdl.handle.net/10962/438310 , vital:73450 , ISBN 978-1-4312-0070-2 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/KV259-10.pdf
- Description: An important aspect of the dynamics of nutrients and pollutants in natural systems is captured in the concept of allochthony, founded on the observation that nutrients and energy in a variety of forms are transferred between adjacent habitats, com-munities and ecosystems that are not routinely considered as connected. Different forms of nutrients and energy move across the conceptual boundaries of habitats via organisms’ activities or physical processes such as wind or water currents, and these transfers can represent important food subsidies. Such cross-partition ecolog-ical subsidies can augment the nutritional condition, biomass and biodiversity of communities, particularly where local production (or autochthony) alone may be inadequate to support local food webs. Furthermore, organic subsidies can influ-ence population dynamics, community interactions and ecosystem processes, and can represent dominant flux inputs in ecosystem budgets. Our intention was to explore organic nutrient fluxes in relation to a primarily lotic (i.e. flowing) aquatic sys-tem at the scale of a hydrological catchment.
- Full Text:
- Date Issued: 2011
- Authors: Gordon, Andrew K , Mantel, Sukhmani K , Muller, Nikite W J
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , report
- Identifier: http://hdl.handle.net/10962/438310 , vital:73450 , ISBN 978-1-4312-0070-2 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/KV259-10.pdf
- Description: An important aspect of the dynamics of nutrients and pollutants in natural systems is captured in the concept of allochthony, founded on the observation that nutrients and energy in a variety of forms are transferred between adjacent habitats, com-munities and ecosystems that are not routinely considered as connected. Different forms of nutrients and energy move across the conceptual boundaries of habitats via organisms’ activities or physical processes such as wind or water currents, and these transfers can represent important food subsidies. Such cross-partition ecolog-ical subsidies can augment the nutritional condition, biomass and biodiversity of communities, particularly where local production (or autochthony) alone may be inadequate to support local food webs. Furthermore, organic subsidies can influ-ence population dynamics, community interactions and ecosystem processes, and can represent dominant flux inputs in ecosystem budgets. Our intention was to explore organic nutrient fluxes in relation to a primarily lotic (i.e. flowing) aquatic sys-tem at the scale of a hydrological catchment.
- Full Text:
- Date Issued: 2011
Ecological impacts of small dams on South African rivers Part 1: Drivers of change–water quantity and quality
- Mantel, Sukhmani K, Hughes, Denis A, Muller, Nikite W J
- Authors: Mantel, Sukhmani K , Hughes, Denis A , Muller, Nikite W J
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , report
- Identifier: http://hdl.handle.net/10962/438099 , vital:73435 , ISBN 1816-7950 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/2398.pdf
- Description: Impacts of large dams are well-known and quantifiable, while small dams have generally been perceived as benign, both socially and envi-ronmentally. The present study quantifies the cumulative impacts of small dams on the water quality (physico-chemistry and invertebrate biotic indices) and quantity (discharge) of downstream rivers in 2 South African regions. The information from 2 South African national data-bases was used for evaluating the cumulative impacts on water quality and quantity. Physico-chemistry and biological data were obtained from the River Health Programme, and discharge data at stream flow gauges was obtained from the Hydrological Information System. Multivariate analyses were conducted to establish broad patterns for cumulative impacts of small dams across the 2 regions–Western Cape (winter rain-fall, temperate, south-western coast) and Mpumalanga (summer rain-fall, tropical, eastern coast). Multivariate analyses found that the chang-es in macroinvertebrate indices and the stream’s physico-chemistry were more strongly correlated with the density of small dams in the catchment (as a measure of cumulative impact potential) relative to the storage capacity of large dams. T-tests on the data, not including sam-ples with upstream large dams, indicated that the high density of small dams significantly reduced low flows and increased certain physico-chemistry variables (particularly total dissolved salts) in both the re-gions, along with associated significant reductions in a macroinverte-brate index (SASS4 average score per taxon). Regional differences were apparent in the results for discharge reductions and the macroin-vertebrate index. The results suggest that the cumulative effect of a high number of small dams is impacting the quality and quantity of wa-ters in South African rivers and that these impacts need to be systemat-ically incorporated into the monitoring protocol of the environmental wa-ter requirements.
- Full Text:
- Date Issued: 2010
- Authors: Mantel, Sukhmani K , Hughes, Denis A , Muller, Nikite W J
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , report
- Identifier: http://hdl.handle.net/10962/438099 , vital:73435 , ISBN 1816-7950 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/2398.pdf
- Description: Impacts of large dams are well-known and quantifiable, while small dams have generally been perceived as benign, both socially and envi-ronmentally. The present study quantifies the cumulative impacts of small dams on the water quality (physico-chemistry and invertebrate biotic indices) and quantity (discharge) of downstream rivers in 2 South African regions. The information from 2 South African national data-bases was used for evaluating the cumulative impacts on water quality and quantity. Physico-chemistry and biological data were obtained from the River Health Programme, and discharge data at stream flow gauges was obtained from the Hydrological Information System. Multivariate analyses were conducted to establish broad patterns for cumulative impacts of small dams across the 2 regions–Western Cape (winter rain-fall, temperate, south-western coast) and Mpumalanga (summer rain-fall, tropical, eastern coast). Multivariate analyses found that the chang-es in macroinvertebrate indices and the stream’s physico-chemistry were more strongly correlated with the density of small dams in the catchment (as a measure of cumulative impact potential) relative to the storage capacity of large dams. T-tests on the data, not including sam-ples with upstream large dams, indicated that the high density of small dams significantly reduced low flows and increased certain physico-chemistry variables (particularly total dissolved salts) in both the re-gions, along with associated significant reductions in a macroinverte-brate index (SASS4 average score per taxon). Regional differences were apparent in the results for discharge reductions and the macroin-vertebrate index. The results suggest that the cumulative effect of a high number of small dams is impacting the quality and quantity of wa-ters in South African rivers and that these impacts need to be systemat-ically incorporated into the monitoring protocol of the environmental wa-ter requirements.
- Full Text:
- Date Issued: 2010
Ecological impacts of small dams on South African rivers Part 2: Biotic response – abundance and composition of macroinvertebrate communities
- Mantel, Sukhmani K, Muller, Nikite W J, Hughes, Denis A
- Authors: Mantel, Sukhmani K , Muller, Nikite W J , Hughes, Denis A
- Date: 2010
- Language: English
- Type: text , Article
- Identifier: vital:7095 , http://hdl.handle.net/10962/d1012437
- Description: This paper investigates the cumulative impacts of small dams on invertebrate communities in 2 regions of South Africa – the Western Cape and Mpumalanga. Previous research found reduced discharge, increased total dissolved salts, and a decrease in average score per taxon (ASPT; collected using SASS4 methods) at sites with high density of small dams in their catchment. These changes in ASPT are investigated using the invertebrate abundance data available in the River Health Programme. Multivariate analyses found differences in invertebrate communities in rivers with high densities of small dams in their catchment in foothill-gravel streams (in both Western Cape and Mpumalanga) and in foothill-cobble streams (in Western Cape only). Opportunistic taxa that are tolerant of pollution, and capable of exploiting various habitats, and those that prefer slower currents increased in numbers, while other taxa that are sensitive to pollution and disturbance declined in numbers. Some regional differences were noted possibly reflecting climatic differences between the regions. Since the results of this study are correlative, it highlights the need for a systematic (by sites and seasons) and detailed (at species level) collection of data to verify the results of cumulative effects of small dams. This can further the development of a framework for small-dam construction and management that will limit their impact on river catchments.
- Full Text:
- Date Issued: 2010
- Authors: Mantel, Sukhmani K , Muller, Nikite W J , Hughes, Denis A
- Date: 2010
- Language: English
- Type: text , Article
- Identifier: vital:7095 , http://hdl.handle.net/10962/d1012437
- Description: This paper investigates the cumulative impacts of small dams on invertebrate communities in 2 regions of South Africa – the Western Cape and Mpumalanga. Previous research found reduced discharge, increased total dissolved salts, and a decrease in average score per taxon (ASPT; collected using SASS4 methods) at sites with high density of small dams in their catchment. These changes in ASPT are investigated using the invertebrate abundance data available in the River Health Programme. Multivariate analyses found differences in invertebrate communities in rivers with high densities of small dams in their catchment in foothill-gravel streams (in both Western Cape and Mpumalanga) and in foothill-cobble streams (in Western Cape only). Opportunistic taxa that are tolerant of pollution, and capable of exploiting various habitats, and those that prefer slower currents increased in numbers, while other taxa that are sensitive to pollution and disturbance declined in numbers. Some regional differences were noted possibly reflecting climatic differences between the regions. Since the results of this study are correlative, it highlights the need for a systematic (by sites and seasons) and detailed (at species level) collection of data to verify the results of cumulative effects of small dams. This can further the development of a framework for small-dam construction and management that will limit their impact on river catchments.
- Full Text:
- Date Issued: 2010
Ecological impacts of small dams on South African rivers Part 2: Biotic response–abundance and composition of macroinvertebrate communities
- Mantel, Sukhmani K, Muller, Nikite W J, Hughes, Denis A
- Authors: Mantel, Sukhmani K , Muller, Nikite W J , Hughes, Denis A
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , report
- Identifier: http://hdl.handle.net/10962/438087 , vital:73434 , ISBN 1816-7950 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/2354.pdf
- Description: This paper investigates the cumulative impacts of small dams on inver-tebrate communities in 2 regions of South Africa–the Western Cape and Mpumalanga. Previous research found reduced discharge, in-creased total dissolved salts, and a decrease in average score per tax-on (ASPT; collected using SASS4 methods) at sites with high density of small dams in their catchment. These changes in ASPT are investigat-ed using the invertebrate abundance data available in the River Health Programme. Multivariate analyses found differences in invertebrate communities in rivers with high densities of small dams in their catch-ment in foothill-gravel streams (in both Western Cape and Mpuma-langa) and in foothill-cobble streams (in Western Cape only). Opportun-istic taxa that are tolerant of pollution, and capable of exploiting various habitats, and those that prefer slower currents increased in numbers, while other taxa that are sensitive to pollution and disturbance declined in numbers. Some regional differences were noted possibly reflecting climatic differences between the regions. Since the results of this study are correlative, it highlights the need for a systematic (by sites and sea-sons) and detailed (at species level) collection of data to verify the re-sults of cumulative effects of small dams. This can further the devel-opment of a framework for small-dam construction and management that will limit their impact on river catchments.
- Full Text:
- Date Issued: 2010
- Authors: Mantel, Sukhmani K , Muller, Nikite W J , Hughes, Denis A
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , report
- Identifier: http://hdl.handle.net/10962/438087 , vital:73434 , ISBN 1816-7950 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/2354.pdf
- Description: This paper investigates the cumulative impacts of small dams on inver-tebrate communities in 2 regions of South Africa–the Western Cape and Mpumalanga. Previous research found reduced discharge, in-creased total dissolved salts, and a decrease in average score per tax-on (ASPT; collected using SASS4 methods) at sites with high density of small dams in their catchment. These changes in ASPT are investigat-ed using the invertebrate abundance data available in the River Health Programme. Multivariate analyses found differences in invertebrate communities in rivers with high densities of small dams in their catch-ment in foothill-gravel streams (in both Western Cape and Mpuma-langa) and in foothill-cobble streams (in Western Cape only). Opportun-istic taxa that are tolerant of pollution, and capable of exploiting various habitats, and those that prefer slower currents increased in numbers, while other taxa that are sensitive to pollution and disturbance declined in numbers. Some regional differences were noted possibly reflecting climatic differences between the regions. Since the results of this study are correlative, it highlights the need for a systematic (by sites and sea-sons) and detailed (at species level) collection of data to verify the re-sults of cumulative effects of small dams. This can further the devel-opment of a framework for small-dam construction and management that will limit their impact on river catchments.
- Full Text:
- Date Issued: 2010
Osmoregulation in freshwater invertebrates in response to exposure to salt pollution
- Holland, Alexandra J, Gordon, Andrew K, Muller, Nikite W J
- Authors: Holland, Alexandra J , Gordon, Andrew K , Muller, Nikite W J
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , report
- Identifier: http://hdl.handle.net/10962/437700 , vital:73403 , ISBN 978-1-4312-0075-7 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/1585.pdf
- Description: The South African National Water Act (No. 36 of 1998) provides for an ecological Reserve which is intended to protect fresh water ecosystems and resources from degradation as a result of misuse, and to maintain vital ecological functions within these systems (Palmer et al., 2004). Water quality guidelines are an important tool in the management of these water resources, aiming to adequately balance protec-tion of aquatic ecological systems with sustainable human use needs. Jooste and Rossouw (2002) proposed guidelines or boundary values for inorganic salts to be included in the ecological Reserve. These boundary values for inorganic salts were derived as follows, acute lethality data (LC50s) from the ECOTOX database main-tained by the USEPA were projected to 336 h and the 5th percentile determined as a lethality benchmark, analogous to the Fair/Poor boundary. Similarly, the 5th percen-tile of available sublethal data was determined as the sublethality benchmark and analogous with the Natural/Good boundary value. The Good/Fair boundary was the mean value between Natural/Good and Fair/Poor values. It has been suggested however, that these guidelines might not be entirely appropriate as they were de-rived without including tolerances of South African biota. Furthermore, the accuracy for some salt boundary values have been questioned (Scherman, 2009; Scherman, 2010).
- Full Text:
- Date Issued: 2010
- Authors: Holland, Alexandra J , Gordon, Andrew K , Muller, Nikite W J
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , report
- Identifier: http://hdl.handle.net/10962/437700 , vital:73403 , ISBN 978-1-4312-0075-7 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/1585.pdf
- Description: The South African National Water Act (No. 36 of 1998) provides for an ecological Reserve which is intended to protect fresh water ecosystems and resources from degradation as a result of misuse, and to maintain vital ecological functions within these systems (Palmer et al., 2004). Water quality guidelines are an important tool in the management of these water resources, aiming to adequately balance protec-tion of aquatic ecological systems with sustainable human use needs. Jooste and Rossouw (2002) proposed guidelines or boundary values for inorganic salts to be included in the ecological Reserve. These boundary values for inorganic salts were derived as follows, acute lethality data (LC50s) from the ECOTOX database main-tained by the USEPA were projected to 336 h and the 5th percentile determined as a lethality benchmark, analogous to the Fair/Poor boundary. Similarly, the 5th percen-tile of available sublethal data was determined as the sublethality benchmark and analogous with the Natural/Good boundary value. The Good/Fair boundary was the mean value between Natural/Good and Fair/Poor values. It has been suggested however, that these guidelines might not be entirely appropriate as they were de-rived without including tolerances of South African biota. Furthermore, the accuracy for some salt boundary values have been questioned (Scherman, 2009; Scherman, 2010).
- Full Text:
- Date Issued: 2010
Larval development of the carrion-breeding flesh fly, Sarcophaga (Liosarcophaga) tibialis Macquart (Diptera: Sarcophagidae), at constant temperatures
- Villet, Martin H, MacKenzie, Bernard L, Muller, Nikite W J
- Authors: Villet, Martin H , MacKenzie, Bernard L , Muller, Nikite W J
- Date: 2006
- Language: English
- Type: text , Article
- Identifier: vital:7091 , http://hdl.handle.net/10962/d1012422
- Description: Larvae of Sarcophaga (Liosarcophaga) tibialis Macquart were raised on chicken liver under six different constant temperatures. Maximum survival indicated an optimal developmental temperature of near 20°C, while trends in mortality, larval length and larval mass implied that the thermal window for successful development lay between 15°C and 30°C. Using a recently described method to estimate a simple thermal summation model, it was found that the timing of the end of the feeding phase could be estimated by a developmental zero (D0) of 5.2°C (S.E. = 1.21) and a thermal summation constant (K) of 106.4 d°C (S.E. = 8.31) and of the end of the wandering phase by D0 = 4.1°C (S.E. = 0.39) and K = 126.7 d°C (S.E. = 3.28). Published development times at constant temperatures were compiled for 19 other species of flesh flies, and the developmental constants were calculated for six species for which sufficient data were accumulated.
- Full Text:
- Date Issued: 2006
- Authors: Villet, Martin H , MacKenzie, Bernard L , Muller, Nikite W J
- Date: 2006
- Language: English
- Type: text , Article
- Identifier: vital:7091 , http://hdl.handle.net/10962/d1012422
- Description: Larvae of Sarcophaga (Liosarcophaga) tibialis Macquart were raised on chicken liver under six different constant temperatures. Maximum survival indicated an optimal developmental temperature of near 20°C, while trends in mortality, larval length and larval mass implied that the thermal window for successful development lay between 15°C and 30°C. Using a recently described method to estimate a simple thermal summation model, it was found that the timing of the end of the feeding phase could be estimated by a developmental zero (D0) of 5.2°C (S.E. = 1.21) and a thermal summation constant (K) of 106.4 d°C (S.E. = 8.31) and of the end of the wandering phase by D0 = 4.1°C (S.E. = 0.39) and K = 126.7 d°C (S.E. = 3.28). Published development times at constant temperatures were compiled for 19 other species of flesh flies, and the developmental constants were calculated for six species for which sufficient data were accumulated.
- Full Text:
- Date Issued: 2006
The six-legged flying squad
- Villet, Martin H, Muller, Nikite W J
- Authors: Villet, Martin H , Muller, Nikite W J
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/442677 , vital:74020 , https://journals.co.za/doi/pdf/10.10520/AJA1729830X_227
- Description: How do bugs and insects help forensic entomologists to settle disputes and solve crimes? Martin Villet and Nikite Muller explain.
- Full Text:
- Date Issued: 2006
- Authors: Villet, Martin H , Muller, Nikite W J
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/442677 , vital:74020 , https://journals.co.za/doi/pdf/10.10520/AJA1729830X_227
- Description: How do bugs and insects help forensic entomologists to settle disputes and solve crimes? Martin Villet and Nikite Muller explain.
- Full Text:
- Date Issued: 2006
The development of water quality methods within ecological Reserve assessments, and links to environmental flows
- Palmer, Carolyn G, Rossouw, N, Muller, Nikite W J, Scherman, Patricia A
- Authors: Palmer, Carolyn G , Rossouw, N , Muller, Nikite W J , Scherman, Patricia A
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , report
- Identifier: http://hdl.handle.net/10962/438033 , vital:73430 , ISBN 0378-4738 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/WaterSA_2005_02_1634.pdf
- Description: In the South African National Water Act (NWA, No 36 of 1998), the eco-logical Reserve is defined as the quality and quantity of water required to ensure appropriate protection of water resources, so as to secure ecologically sustainable development and use. Aquatic ecosystems are recognised as the core location of water resources, and although con-siderable progress has been made in developing methods for quantify-ing environmental flow requirements, this paper describes and discuss-es the first agreed method for quantifying environmental water quality requirements in an ecological Reserve assessment. Integration of flow and water quality is emphasised, and is based on the philosophy that environmental flows should be motivated to provide ecologically im-portant flow-related habitat, or geomorphological function, but should not be motivated to solve water quality problems by dilution. Water qual-ity is multivariate, and not all variables can be considered in an ecologi-cal Reserve assessment, but core water quality variables include: sys-tem variables (salts, dissolved oxygen, turbidity, temperature), nutrients (phosphate, nitrite, nitrate) and toxic substances (those listed in the South African Water Quality Guidelines for Aquatic Ecosystems, includ-ing toxic metal ions, toxic organic substances, and/or substances from a chemical inventory of an effluent or discharge). In addition, biological indicator data (eg SASS data), chlorophyll-a (eg phytoplankton and pe-riphyton data) and toxicity test data may be used. For each variable, a concentration range or response is linked to a class within a water re-source classification system, where classes range from minimally to severely modified.
- Full Text:
- Date Issued: 2005
- Authors: Palmer, Carolyn G , Rossouw, N , Muller, Nikite W J , Scherman, Patricia A
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , report
- Identifier: http://hdl.handle.net/10962/438033 , vital:73430 , ISBN 0378-4738 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/WaterSA_2005_02_1634.pdf
- Description: In the South African National Water Act (NWA, No 36 of 1998), the eco-logical Reserve is defined as the quality and quantity of water required to ensure appropriate protection of water resources, so as to secure ecologically sustainable development and use. Aquatic ecosystems are recognised as the core location of water resources, and although con-siderable progress has been made in developing methods for quantify-ing environmental flow requirements, this paper describes and discuss-es the first agreed method for quantifying environmental water quality requirements in an ecological Reserve assessment. Integration of flow and water quality is emphasised, and is based on the philosophy that environmental flows should be motivated to provide ecologically im-portant flow-related habitat, or geomorphological function, but should not be motivated to solve water quality problems by dilution. Water qual-ity is multivariate, and not all variables can be considered in an ecologi-cal Reserve assessment, but core water quality variables include: sys-tem variables (salts, dissolved oxygen, turbidity, temperature), nutrients (phosphate, nitrite, nitrate) and toxic substances (those listed in the South African Water Quality Guidelines for Aquatic Ecosystems, includ-ing toxic metal ions, toxic organic substances, and/or substances from a chemical inventory of an effluent or discharge). In addition, biological indicator data (eg SASS data), chlorophyll-a (eg phytoplankton and pe-riphyton data) and toxicity test data may be used. For each variable, a concentration range or response is linked to a class within a water re-source classification system, where classes range from minimally to severely modified.
- Full Text:
- Date Issued: 2005
Applied aquatic ecotoxicology sub-lethal methods, whole effluent testing and communication
- Palmer, Carolyn G, Muller, Nikite W J, Davies-Coleman, Heather D
- Authors: Palmer, Carolyn G , Muller, Nikite W J , Davies-Coleman, Heather D
- Date: 2004
- Subjects: To be catalogued
- Language: English
- Type: text , report
- Identifier: http://hdl.handle.net/10962/437785 , vital:73409 , ISBN 1-77005-252-6 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/1245-1-041.pdf
- Description: This report is the most recent in a series of WRC reports on the development of the capacity to undertake ecotoxicological research in South Africa. The development followed the following tines: • Recognition, as a result of the Kruger National Park Rivers Research Programme, that there were virtually no data on the water quality requirements of South African macroin vertebrates. • Development of the capacity to undertake experimental tolerance testing using riverine invertebrates in artificial stream systems. • Investigation of the salt tolerances, and whole effluent toxicity responses, of both standard toxicity test taxa and South African macroinverte-brates. • Development of both lethal and sub-lethal measures. • Application of re-search results to the development of methods for water quality within ecological Reserve determinations, and the implementation of the National Water Act (NWA) (No 36. of 1998) and National Water Resource Strategy (NWRS). The WRC is com-mitted to funding research that underpins the implementation of the NWA and the NWRS. Over the past 12 years it became clear that there would not be a rapid up-take of ecotoxicology research results in South Africa, and that it was important to place ecotoxicology in the wider context of water quality. From this recognition, the concept of Environmental Water Quality evolved.
- Full Text:
- Date Issued: 2004
- Authors: Palmer, Carolyn G , Muller, Nikite W J , Davies-Coleman, Heather D
- Date: 2004
- Subjects: To be catalogued
- Language: English
- Type: text , report
- Identifier: http://hdl.handle.net/10962/437785 , vital:73409 , ISBN 1-77005-252-6 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/1245-1-041.pdf
- Description: This report is the most recent in a series of WRC reports on the development of the capacity to undertake ecotoxicological research in South Africa. The development followed the following tines: • Recognition, as a result of the Kruger National Park Rivers Research Programme, that there were virtually no data on the water quality requirements of South African macroin vertebrates. • Development of the capacity to undertake experimental tolerance testing using riverine invertebrates in artificial stream systems. • Investigation of the salt tolerances, and whole effluent toxicity responses, of both standard toxicity test taxa and South African macroinverte-brates. • Development of both lethal and sub-lethal measures. • Application of re-search results to the development of methods for water quality within ecological Reserve determinations, and the implementation of the National Water Act (NWA) (No 36. of 1998) and National Water Resource Strategy (NWRS). The WRC is com-mitted to funding research that underpins the implementation of the NWA and the NWRS. Over the past 12 years it became clear that there would not be a rapid up-take of ecotoxicology research results in South Africa, and that it was important to place ecotoxicology in the wider context of water quality. From this recognition, the concept of Environmental Water Quality evolved.
- Full Text:
- Date Issued: 2004
Early development of water quality methods and approaches in ecological Reserve assessments
- Palmer, Carolyn G, Scherman, Patricia, Muller, Nikite W J, Rossouw, J N, Malan, H L, Jooste, S
- Authors: Palmer, Carolyn G , Scherman, Patricia , Muller, Nikite W J , Rossouw, J N , Malan, H L , Jooste, S
- Date: 2004
- Subjects: To be catalogued
- Language: English
- Type: text , report
- Identifier: http://hdl.handle.net/10962/437840 , vital:73416 , ISBN 1-77005-227-5 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/1108-1-041.pdf
- Description: This project was initiated in 2000 to allow the ecological Reserve team for water quality to undertake additional research while working on eco-logical Reserve determinations funded by the Department of Water Af-fairs and Forestry. The results of this work form the basis of the meth-ods reported in the Water Research Commission report Hughes DA (Ed)(in press).
- Full Text:
- Date Issued: 2004
- Authors: Palmer, Carolyn G , Scherman, Patricia , Muller, Nikite W J , Rossouw, J N , Malan, H L , Jooste, S
- Date: 2004
- Subjects: To be catalogued
- Language: English
- Type: text , report
- Identifier: http://hdl.handle.net/10962/437840 , vital:73416 , ISBN 1-77005-227-5 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/1108-1-041.pdf
- Description: This project was initiated in 2000 to allow the ecological Reserve team for water quality to undertake additional research while working on eco-logical Reserve determinations funded by the Department of Water Af-fairs and Forestry. The results of this work form the basis of the meth-ods reported in the Water Research Commission report Hughes DA (Ed)(in press).
- Full Text:
- Date Issued: 2004
Environmental water quality in water resources management
- Palmer, Carolyn G, Berold, Robert, Muller, Nikite W J
- Authors: Palmer, Carolyn G , Berold, Robert , Muller, Nikite W J
- Date: 2004
- Subjects: To be catalogued
- Language: English
- Type: text , report
- Identifier: http://hdl.handle.net/10962/437611 , vital:73397 , ISBN 1-77005-083-3 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/TT217-04.pdf
- Description: This book will help anyone working with water resources to make decisions about water quality, specifically environmental aspects of water quality. The book ex-plores the balance between water resource protection and water resource use, with a particular focus on water quality. A balance is necessary because the National Wa-ter Act (NWA) requires that water resources be protected and managed to meet the water quality requirements of ecosystems. At the same time the Act also requires that water be used for social and economic benefit.
- Full Text:
- Date Issued: 2004
- Authors: Palmer, Carolyn G , Berold, Robert , Muller, Nikite W J
- Date: 2004
- Subjects: To be catalogued
- Language: English
- Type: text , report
- Identifier: http://hdl.handle.net/10962/437611 , vital:73397 , ISBN 1-77005-083-3 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/TT217-04.pdf
- Description: This book will help anyone working with water resources to make decisions about water quality, specifically environmental aspects of water quality. The book ex-plores the balance between water resource protection and water resource use, with a particular focus on water quality. A balance is necessary because the National Wa-ter Act (NWA) requires that water resources be protected and managed to meet the water quality requirements of ecosystems. At the same time the Act also requires that water be used for social and economic benefit.
- Full Text:
- Date Issued: 2004
Similarities and differences between rivers of the Kruger National Park
- Muller, Nikite W J, Villet, Martin H
- Authors: Muller, Nikite W J , Villet, Martin H
- Date: 2004
- Language: English
- Type: text
- Identifier: vital:537 , http://hdl.handle.net/10962/d1009527
- Description: [From Introduction] Aquatic ecosystems play an important role in the maintenance of ecological diversity and ecosystem functioning at both local and regional scales (Roux et al, 1999). Effective management of riverine ecosystems requires an understanding of their ecosystem processes, hi order to understand ecosystem processes, and interactions between the landscape and riverine ecosystems, it is necessary to have both spatial and temporal data at both landscape and site-specific scales (Allan and Johnson, 1997). There are many tools available for the analysis of these data to provide insight and understanding of the data in order to understand influences on aquatic ecosystems. Increasingly complex computational tools allow analysis and modeling of data in order to explain river, and subsequent biological, processes from landscape (catchment) processes (Johnson and Gage, 1997), although the scale at which analysis and interpretation occurs is important. Science and management need to interact in order to truly succeed in effectively applying adaptive management and incorporate monitoring and assessment programmes in management processes (Rogers and Biggs, 1999). However, water resource management is often undertaken in the context of incomplete information and knowledge of functioning ecosystem processess and responses: this inevitably leads to uncertainty and unpredictability (Roux et al. 1999). One of the major challenges for managing rivers is to be able to monitor rivers effectively in order to detect changes as they occur, to identify the causes of the changes and to distinguish between natural and anthropogenic causes of change. Adaptive management is required to effectively manage rivers, but this does require that there is an understanding of, and information for, the rivers being managed. Rogers and Biggs (1999) highlighted the need to integrate monitoring programmes with indicators in order to undertake assessments of ecosystem health as part of the management plan of the rivers of the Kruger National Park in order to maintain, and restore, natural river ecosystem health and biodiversity (Rogers and Bestbier, 1997). One of the main aims of the Kruger National Park Rivers Research Programme (KNPRRP) was to contribute to the conservation of the natural environment by developing skills and methods to understand the ecological functioning of the natural environment and to predict responses of the river systems to natural and anthropogenic changes in order to effectively manage them (Breen, 1994, in van Rensburg and Dent, 1997). Classification systems are able to provide useful management information, but many have focussed on abiotic rather than biotic factors because resultant biotic patterns are likely to be correlated with abiotic components (Solomon et al., 1999). Much of the classification of the Kruger National Park has focussed on classification of land with little regard for rivers (these were incorporated into the two classification systems proposed by Venter and Gertenbach (in Solomon et al., 1999)). The objective of this project is to identify similarities and differences between the five major rivers of the Kruger National Park, towards the design and testing of a classification framework in order to aid management of the KNP rivers by contributing to effective monitoring. This will be achieved through the following: 1. collate available (current and historical) information concerning physical and biological variables for the Luvuvhu, Letaba, Olifants, Sabie and Crocodile Rivers, using a common dataset to establish the degree of similarities and differences between these five major rivers of the KNP; and 2. determine how different the rivers are, in order to optimize monitoring and management programmes for these differences. The aim of this project was not to classify the rivers of the KNP. The project rather aims to identify gaps in data availability which may result in inadequate and inappropriate management of the rivers. Results (in the form of a data matrix) emanating from this study could assist in establishing expected natural conditions and biota in the five major rivers of the KNP, and knowledge from data-rich rivers (e.g. Sabie River) could potentially be extrapolated to data-poor rivers, or sections of rivers. Invertebrates and fish are the main tools of aquatic species biodiversity monitoring, and require an understanding of the natural presence, absence and abundance patterns in aquatic ecosystems. This study contributes to this understanding by organising available information of biotic and abiotic information.
- Full Text:
- Date Issued: 2004
- Authors: Muller, Nikite W J , Villet, Martin H
- Date: 2004
- Language: English
- Type: text
- Identifier: vital:537 , http://hdl.handle.net/10962/d1009527
- Description: [From Introduction] Aquatic ecosystems play an important role in the maintenance of ecological diversity and ecosystem functioning at both local and regional scales (Roux et al, 1999). Effective management of riverine ecosystems requires an understanding of their ecosystem processes, hi order to understand ecosystem processes, and interactions between the landscape and riverine ecosystems, it is necessary to have both spatial and temporal data at both landscape and site-specific scales (Allan and Johnson, 1997). There are many tools available for the analysis of these data to provide insight and understanding of the data in order to understand influences on aquatic ecosystems. Increasingly complex computational tools allow analysis and modeling of data in order to explain river, and subsequent biological, processes from landscape (catchment) processes (Johnson and Gage, 1997), although the scale at which analysis and interpretation occurs is important. Science and management need to interact in order to truly succeed in effectively applying adaptive management and incorporate monitoring and assessment programmes in management processes (Rogers and Biggs, 1999). However, water resource management is often undertaken in the context of incomplete information and knowledge of functioning ecosystem processess and responses: this inevitably leads to uncertainty and unpredictability (Roux et al. 1999). One of the major challenges for managing rivers is to be able to monitor rivers effectively in order to detect changes as they occur, to identify the causes of the changes and to distinguish between natural and anthropogenic causes of change. Adaptive management is required to effectively manage rivers, but this does require that there is an understanding of, and information for, the rivers being managed. Rogers and Biggs (1999) highlighted the need to integrate monitoring programmes with indicators in order to undertake assessments of ecosystem health as part of the management plan of the rivers of the Kruger National Park in order to maintain, and restore, natural river ecosystem health and biodiversity (Rogers and Bestbier, 1997). One of the main aims of the Kruger National Park Rivers Research Programme (KNPRRP) was to contribute to the conservation of the natural environment by developing skills and methods to understand the ecological functioning of the natural environment and to predict responses of the river systems to natural and anthropogenic changes in order to effectively manage them (Breen, 1994, in van Rensburg and Dent, 1997). Classification systems are able to provide useful management information, but many have focussed on abiotic rather than biotic factors because resultant biotic patterns are likely to be correlated with abiotic components (Solomon et al., 1999). Much of the classification of the Kruger National Park has focussed on classification of land with little regard for rivers (these were incorporated into the two classification systems proposed by Venter and Gertenbach (in Solomon et al., 1999)). The objective of this project is to identify similarities and differences between the five major rivers of the Kruger National Park, towards the design and testing of a classification framework in order to aid management of the KNP rivers by contributing to effective monitoring. This will be achieved through the following: 1. collate available (current and historical) information concerning physical and biological variables for the Luvuvhu, Letaba, Olifants, Sabie and Crocodile Rivers, using a common dataset to establish the degree of similarities and differences between these five major rivers of the KNP; and 2. determine how different the rivers are, in order to optimize monitoring and management programmes for these differences. The aim of this project was not to classify the rivers of the KNP. The project rather aims to identify gaps in data availability which may result in inadequate and inappropriate management of the rivers. Results (in the form of a data matrix) emanating from this study could assist in establishing expected natural conditions and biota in the five major rivers of the KNP, and knowledge from data-rich rivers (e.g. Sabie River) could potentially be extrapolated to data-poor rivers, or sections of rivers. Invertebrates and fish are the main tools of aquatic species biodiversity monitoring, and require an understanding of the natural presence, absence and abundance patterns in aquatic ecosystems. This study contributes to this understanding by organising available information of biotic and abiotic information.
- Full Text:
- Date Issued: 2004
Use of indigenous riverine invertebrates in applied toxicology and water resource-quality management
- Scherman, Patricia, Palmer, Carolyn G, Muller, Nikite W J
- Authors: Scherman, Patricia , Palmer, Carolyn G , Muller, Nikite W J
- Date: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , report
- Identifier: http://hdl.handle.net/10962/438061 , vital:73432 , ISBN 1-86845-962-4 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/955-1-03.pdf
- Description: The National Water Policy (DWAF, 1997). and the National Water Act (No 36 of 1998)(NWA) provide the legal and management context for the application of results. The law and the policy are founded on the concepts of equity (fairness of access to water and water services) and sustainability (the opportunity to optimally use water resources now and into the future)(NWA, l (l)(xviii)(b)). The concept of sustainability is based on the understanding that on earth water comes packaged in aquatic ecosystems, and that the product, water, is intimately related to and affected by the structure and functioning of these ecosys-tems.(Aquatic ecosystems include rivers, lakes, wetlands, aquifers and estuaries. Impoundments act as artificial lakes connected to river sys-tems.) A key recognition during the development of the policy and the NWA was that" the environment" does not compete with users for re-sources-the environment (in this case aquatic ecosystems) is the re-source. Therefore a key poiicy of DWAF is that vi resource protection in order to achieve sustainable resource use. Resource protection is achieved through the implementation of resource directed measures (RDM) and source directed controls (SDC).
- Full Text:
- Date Issued: 2003
Use of indigenous riverine invertebrates in applied toxicology and water resource-quality management
- Authors: Scherman, Patricia , Palmer, Carolyn G , Muller, Nikite W J
- Date: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , report
- Identifier: http://hdl.handle.net/10962/438061 , vital:73432 , ISBN 1-86845-962-4 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/955-1-03.pdf
- Description: The National Water Policy (DWAF, 1997). and the National Water Act (No 36 of 1998)(NWA) provide the legal and management context for the application of results. The law and the policy are founded on the concepts of equity (fairness of access to water and water services) and sustainability (the opportunity to optimally use water resources now and into the future)(NWA, l (l)(xviii)(b)). The concept of sustainability is based on the understanding that on earth water comes packaged in aquatic ecosystems, and that the product, water, is intimately related to and affected by the structure and functioning of these ecosys-tems.(Aquatic ecosystems include rivers, lakes, wetlands, aquifers and estuaries. Impoundments act as artificial lakes connected to river sys-tems.) A key recognition during the development of the policy and the NWA was that" the environment" does not compete with users for re-sources-the environment (in this case aquatic ecosystems) is the re-source. Therefore a key poiicy of DWAF is that vi resource protection in order to achieve sustainable resource use. Resource protection is achieved through the implementation of resource directed measures (RDM) and source directed controls (SDC).
- Full Text:
- Date Issued: 2003
Some For All Forever: Water Ecosystems and People
- Palmer, Carolyn G, Berold, Robert, Muller, Nikite W J, Scherman, Patricia
- Authors: Palmer, Carolyn G , Berold, Robert , Muller, Nikite W J , Scherman, Patricia
- Date: 2002
- Subjects: To be catalogued
- Language: English
- Type: text , report
- Identifier: http://hdl.handle.net/10962/437599 , vital:73396 , ISBN 1 86845 850 4 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/TT 176 complete.pdf
- Description: Water for people and people for water. We need water and water needs us. That is what this book is about. Water is the basis of all life. No plant, animal or person on earth can survive without it. In fact, all organisms are mostly made up of water. Wa-ter shapes the earth’s surface. It is a fundamental part of climate processes. Out in the natural world, water is not found in taps, buckets and glasses but in rivers, wet-lands, lakes, dams, estuaries, groundwater and the sea. It falls from the sky as rain, runs off the landscape, filters into the soil, flows to the sea in rivers, is stored in dams, evaporates into the sky, and rains back onto the earth. This is the water cycle. People need water for all sorts of things, for drinking, washing, cooking, growing food, in industries, and to dilute and transport wastes. But in the process of using water, people can damage rivers, wetlands, lakes and other watery places. Dam-aged ecosystems do not work very well and may fail us when we need them most. The message of this book is – look after water in the places where it is naturally found – look after water and water ecosystems because you need them so much.
- Full Text:
- Date Issued: 2002
- Authors: Palmer, Carolyn G , Berold, Robert , Muller, Nikite W J , Scherman, Patricia
- Date: 2002
- Subjects: To be catalogued
- Language: English
- Type: text , report
- Identifier: http://hdl.handle.net/10962/437599 , vital:73396 , ISBN 1 86845 850 4 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/TT 176 complete.pdf
- Description: Water for people and people for water. We need water and water needs us. That is what this book is about. Water is the basis of all life. No plant, animal or person on earth can survive without it. In fact, all organisms are mostly made up of water. Wa-ter shapes the earth’s surface. It is a fundamental part of climate processes. Out in the natural world, water is not found in taps, buckets and glasses but in rivers, wet-lands, lakes, dams, estuaries, groundwater and the sea. It falls from the sky as rain, runs off the landscape, filters into the soil, flows to the sea in rivers, is stored in dams, evaporates into the sky, and rains back onto the earth. This is the water cycle. People need water for all sorts of things, for drinking, washing, cooking, growing food, in industries, and to dilute and transport wastes. But in the process of using water, people can damage rivers, wetlands, lakes and other watery places. Dam-aged ecosystems do not work very well and may fail us when we need them most. The message of this book is – look after water in the places where it is naturally found – look after water and water ecosystems because you need them so much.
- Full Text:
- Date Issued: 2002
The use of Daphnia spp. and indigenous river invertebrates in whole effluent toxicity testing in the Vaal Catchment.
- Muller, Nikite W J, Palmer, Carolyn G
- Authors: Muller, Nikite W J , Palmer, Carolyn G
- Date: 2002
- Subjects: To be catalogued
- Language: English
- Type: text , report
- Identifier: http://hdl.handle.net/10962/438048 , vital:73431 , ISBN 1 86845 855 5 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/815-1-02.pdf
- Description: Freshwater is vital to societal, and environmental, well-being and any changes in the distribution, abundance and quality of water resources and ecosystems are detrimental to this societal and environmental sus-tainability. Increasing socio-economic activities world-wide have been accompanied by increased pollution stress on the aquatic environment. The need for improved efficiency in water quality management is urgent and immediate and it is important that policy to manage freshwater sys-tems is underpinned by sound science. Strategies to manage receiving water quality have been implemented world-wide and include chemical monitoring, biological monitoring and toxicological assessments, all of which are supported by on-going research. Water quality management in South Africa has come a long way since 1919, when it was first promulgated (Union Health Act 36 of 1919; van der Merwe and Grobler, 1990) but only included sewage effluent. Later amendments broadened water quality management to include effluent discharge from industry, mining and storm-water runoff. However, despite these and uniform, and general, effluent standards (UES), as well as DWAFs recognition of the need for integrated water resource management, water quality in the resources continue to deteriorate (DWAF, 1995; Basson etal 1997).
- Full Text:
- Date Issued: 2002
- Authors: Muller, Nikite W J , Palmer, Carolyn G
- Date: 2002
- Subjects: To be catalogued
- Language: English
- Type: text , report
- Identifier: http://hdl.handle.net/10962/438048 , vital:73431 , ISBN 1 86845 855 5 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/815-1-02.pdf
- Description: Freshwater is vital to societal, and environmental, well-being and any changes in the distribution, abundance and quality of water resources and ecosystems are detrimental to this societal and environmental sus-tainability. Increasing socio-economic activities world-wide have been accompanied by increased pollution stress on the aquatic environment. The need for improved efficiency in water quality management is urgent and immediate and it is important that policy to manage freshwater sys-tems is underpinned by sound science. Strategies to manage receiving water quality have been implemented world-wide and include chemical monitoring, biological monitoring and toxicological assessments, all of which are supported by on-going research. Water quality management in South Africa has come a long way since 1919, when it was first promulgated (Union Health Act 36 of 1919; van der Merwe and Grobler, 1990) but only included sewage effluent. Later amendments broadened water quality management to include effluent discharge from industry, mining and storm-water runoff. However, despite these and uniform, and general, effluent standards (UES), as well as DWAFs recognition of the need for integrated water resource management, water quality in the resources continue to deteriorate (DWAF, 1995; Basson etal 1997).
- Full Text:
- Date Issued: 2002
Preliminary observations on the effects of hydrocortisone and sodium methohexital on development of Sarcophaga (Curranea) tibialis Macquart (Diptera: Sarcophagidae), and implications for estimating post mortem interval
- Musvasva, E, Williams, Kirstin A, Muller, Nikite W J, Villet, Martin H
- Authors: Musvasva, E , Williams, Kirstin A , Muller, Nikite W J , Villet, Martin H
- Date: 2001
- Language: English
- Type: text , Article
- Identifier: vital:7075 , http://hdl.handle.net/10962/d1009532
- Description: Larvae of Sarcophaga (Curranea) tibialis (S. tibialis) were reared at constant temperature on chicken liver treated with a steroid or a barbiturate at concentrations that would be lethal, half-lethal and twice-lethal doses for humans. Trends to greater mortality at higher drug concentrations were not statistically significant. Larvae exposed to either drug took significantly longer to reach pupation compared to those in the control, while larvae exposed to sodium methohexital passed through pupation significantly faster than those in the control. No systematic relationship was found between drug concentration and development time of larvae or pupae. The total developmental period from hatching to eclosion did not differ between treatments, implying that estimates of post mortem intervals- (PMI) based on the emergence of adult flies will not be affected by the involvement of these drugs in a case. On the other hand, anomalous pupation spans may indicate the presence of barbiturates. These findings are compared with patterns found in another fly fed other contaminants.
- Full Text:
- Date Issued: 2001
- Authors: Musvasva, E , Williams, Kirstin A , Muller, Nikite W J , Villet, Martin H
- Date: 2001
- Language: English
- Type: text , Article
- Identifier: vital:7075 , http://hdl.handle.net/10962/d1009532
- Description: Larvae of Sarcophaga (Curranea) tibialis (S. tibialis) were reared at constant temperature on chicken liver treated with a steroid or a barbiturate at concentrations that would be lethal, half-lethal and twice-lethal doses for humans. Trends to greater mortality at higher drug concentrations were not statistically significant. Larvae exposed to either drug took significantly longer to reach pupation compared to those in the control, while larvae exposed to sodium methohexital passed through pupation significantly faster than those in the control. No systematic relationship was found between drug concentration and development time of larvae or pupae. The total developmental period from hatching to eclosion did not differ between treatments, implying that estimates of post mortem intervals- (PMI) based on the emergence of adult flies will not be affected by the involvement of these drugs in a case. On the other hand, anomalous pupation spans may indicate the presence of barbiturates. These findings are compared with patterns found in another fly fed other contaminants.
- Full Text:
- Date Issued: 2001
- «
- ‹
- 1
- ›
- »