Derivation of quantitative management objectives for annual instream water temperatures in the Sabie River using a biological index
- Rivers-Moore, Nick A, Jewitt, G P W, Weeks, D C
- Authors: Rivers-Moore, Nick A , Jewitt, G P W , Weeks, D C
- Date: 2005
- Language: English
- Type: text , Article
- Identifier: vital:7093 , http://hdl.handle.net/10962/d1012426
- Description: Adaptive management of river systems assumes uncertainty and makes provision for system variability. Inherent within this management approach is that perceived limits of 'acceptable' system variability are regarded not only as testable hypotheses, but also as playing a central role in maintaining biodiversity. While the Kruger National Park currently functions as a flagship conservation area in South Africa, projected increases in air temperatures as a consequence of global climate change present challenges in conserving this biodiversity inside the established land boundaries. Within the rivers of the Kruger National Park, a management goal of maintaining biodiversity requires a clearer understanding of system variability. One component of this is water temperature, an important water quality parameter defining the distribution patterns of aquatic organisms. In this study, Chiloglanis anoterus Crass (1960) (Pisces: Mochokidae) was selected as a biological indicator of changes in annual water temperatures within the Sabie River in the southern Kruger National Park. Relative abundances of C. anoterus were determined using standard electro-fishing surveys. The presence or absence of C. anoterus was linked to cumulative annual heat units using a logistic regression model, and a critical annual cumulative water temperature threshold estimated. A correlative relationship between this temperature threshold and a biological index using a C. anoterus condition factor provides river ecologists with a tool to assess ecologically significant warming trends in Sabie River water temperatures. A similar approach could be applied with relative ease to other Southern African river systems. Further testing of this hypothesis is suggested, as part of the adaptive management cycle.
- Full Text:
- Authors: Rivers-Moore, Nick A , Jewitt, G P W , Weeks, D C
- Date: 2005
- Language: English
- Type: text , Article
- Identifier: vital:7093 , http://hdl.handle.net/10962/d1012426
- Description: Adaptive management of river systems assumes uncertainty and makes provision for system variability. Inherent within this management approach is that perceived limits of 'acceptable' system variability are regarded not only as testable hypotheses, but also as playing a central role in maintaining biodiversity. While the Kruger National Park currently functions as a flagship conservation area in South Africa, projected increases in air temperatures as a consequence of global climate change present challenges in conserving this biodiversity inside the established land boundaries. Within the rivers of the Kruger National Park, a management goal of maintaining biodiversity requires a clearer understanding of system variability. One component of this is water temperature, an important water quality parameter defining the distribution patterns of aquatic organisms. In this study, Chiloglanis anoterus Crass (1960) (Pisces: Mochokidae) was selected as a biological indicator of changes in annual water temperatures within the Sabie River in the southern Kruger National Park. Relative abundances of C. anoterus were determined using standard electro-fishing surveys. The presence or absence of C. anoterus was linked to cumulative annual heat units using a logistic regression model, and a critical annual cumulative water temperature threshold estimated. A correlative relationship between this temperature threshold and a biological index using a C. anoterus condition factor provides river ecologists with a tool to assess ecologically significant warming trends in Sabie River water temperatures. A similar approach could be applied with relative ease to other Southern African river systems. Further testing of this hypothesis is suggested, as part of the adaptive management cycle.
- Full Text:
A pre-impoundment study of the Sabie-Sand River system, Mpumalanga with special reference to predicted impacts on the Kruger National Park (Volume 3)
- O’Keeffe, Jay H, Weeks, D C, Fourie, A, Davies, B R
- Authors: O’Keeffe, Jay H , Weeks, D C , Fourie, A , Davies, B R
- Date: 1996
- Subjects: To be catalogued
- Language: English
- Type: text , report
- Identifier: http://hdl.handle.net/10962/437759 , vital:73407 , ISBN 1 86845 237 9 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/294-3-96.pdf
- Description: This project was begun in January 1990 in response to a need to characterise the fauna of the Sabie-Sand River system for which plans were already advanced to build impoundments. During the cource of the project, the region was subjected to the worst drought on record. As a result the scope and duration of the project was extended. This volume is the first of three which describe the results. Volume 1 de-scribes the ecological status of the Sabie, the Sand and other major tributaries of the system, including the diversity and distribution of the fish and macro-invertebrate faunas, and their habitat requirements. The second volume describes the results of a drought monitoring programme in which three reaches of the Sabie and one in the Sand River were intensively sampled throughout the worst drought on record, from 1991 to 1992. The purpose of this volume is to assess the probable effects of proposed impoundments in the Sabie-Sand River (both positive and nega-tive) on the ecology of the downstream reaches, and to draw on the information from volumes one and two to make recommendations for the management and monitoring of the flows in the river.
- Full Text:
- Authors: O’Keeffe, Jay H , Weeks, D C , Fourie, A , Davies, B R
- Date: 1996
- Subjects: To be catalogued
- Language: English
- Type: text , report
- Identifier: http://hdl.handle.net/10962/437759 , vital:73407 , ISBN 1 86845 237 9 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/294-3-96.pdf
- Description: This project was begun in January 1990 in response to a need to characterise the fauna of the Sabie-Sand River system for which plans were already advanced to build impoundments. During the cource of the project, the region was subjected to the worst drought on record. As a result the scope and duration of the project was extended. This volume is the first of three which describe the results. Volume 1 de-scribes the ecological status of the Sabie, the Sand and other major tributaries of the system, including the diversity and distribution of the fish and macro-invertebrate faunas, and their habitat requirements. The second volume describes the results of a drought monitoring programme in which three reaches of the Sabie and one in the Sand River were intensively sampled throughout the worst drought on record, from 1991 to 1992. The purpose of this volume is to assess the probable effects of proposed impoundments in the Sabie-Sand River (both positive and nega-tive) on the ecology of the downstream reaches, and to draw on the information from volumes one and two to make recommendations for the management and monitoring of the flows in the river.
- Full Text:
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