The relationship between concurrently measured SASS (South African Scoring System) and turbidity data archived in the South African River Health Programme’s Rivers Database
- Gordon, Andrew K, Griffin, Neil J, Palmer, Carolyn G
- Authors: Gordon, Andrew K , Griffin, Neil J , Palmer, Carolyn G
- Date: 2015
- Language: English
- Type: text , Article
- Identifier: vital:7098 , http://hdl.handle.net/10962/d1015956
- Description: The need for monitoring the biological impacts of instream sediments has long been recognised, yet robust and scientifically defensible tools for doing so are still in the early stages of development because of the difficulties experienced by researchers in characterising the complicated mechanisms of biological effect elicited by sediment particles. Biological monitoring is one such tool, and this paper reports on the initial stages of a study to determine the most applicable approach for measuring the effects of instream sediments on aquatic macroinvertebrates in the South African context. In this first instance, the suitability of the rapid macroinvertebrate biomonitoring tool (the South African Scoring System) was investigated by determining the extent of the correlation between concurrently measured SASS metrics and turbidity data collected for the South African River Health Programme. All three SASS metrics – SASS score, number of taxa (NOT), and average score per taxon (ASPT) – were found to be significantly negatively correlated with turbidity, although variation in the data was high. Turbidity was found to be the major driver of change in ASPT. In contrast, electrical conductivity was the major driver of SASS scores and NOT, with turbidity a close second. When combined, electrical conductivity and turbidity accounted for 80 percent (SASS score) and 75 percent (NOT) of the variation in the regression model. Consequently, SASS metrics are a crude, but reliable, indicator of the negative biological implications of excessive instream sedimentation as measured by turbidity. A number of other potential biomonitoring approaches for detecting the impacts of fine sediment exposure are identified for further investigation: spatial analyses of macroinvertebrate assemblages; and the use of structural and functional metrics.
- Full Text:
- Date Issued: 2015
- Authors: Gordon, Andrew K , Griffin, Neil J , Palmer, Carolyn G
- Date: 2015
- Language: English
- Type: text , Article
- Identifier: vital:7098 , http://hdl.handle.net/10962/d1015956
- Description: The need for monitoring the biological impacts of instream sediments has long been recognised, yet robust and scientifically defensible tools for doing so are still in the early stages of development because of the difficulties experienced by researchers in characterising the complicated mechanisms of biological effect elicited by sediment particles. Biological monitoring is one such tool, and this paper reports on the initial stages of a study to determine the most applicable approach for measuring the effects of instream sediments on aquatic macroinvertebrates in the South African context. In this first instance, the suitability of the rapid macroinvertebrate biomonitoring tool (the South African Scoring System) was investigated by determining the extent of the correlation between concurrently measured SASS metrics and turbidity data collected for the South African River Health Programme. All three SASS metrics – SASS score, number of taxa (NOT), and average score per taxon (ASPT) – were found to be significantly negatively correlated with turbidity, although variation in the data was high. Turbidity was found to be the major driver of change in ASPT. In contrast, electrical conductivity was the major driver of SASS scores and NOT, with turbidity a close second. When combined, electrical conductivity and turbidity accounted for 80 percent (SASS score) and 75 percent (NOT) of the variation in the regression model. Consequently, SASS metrics are a crude, but reliable, indicator of the negative biological implications of excessive instream sedimentation as measured by turbidity. A number of other potential biomonitoring approaches for detecting the impacts of fine sediment exposure are identified for further investigation: spatial analyses of macroinvertebrate assemblages; and the use of structural and functional metrics.
- Full Text:
- Date Issued: 2015
Effect of laundry activities on in-stream concentrations of linear alkylbenzene sulfonate in a small rural South African river
- Gordon, Andrew K, Muller, Wilhelmine J, Gysman, N, Marshall, S J, Sparham, C J, O'Connor, S M, Whelan, M J
- Authors: Gordon, Andrew K , Muller, Wilhelmine J , Gysman, N , Marshall, S J , Sparham, C J , O'Connor, S M , Whelan, M J
- Date: 2009
- Language: English
- Type: text , Article
- Identifier: vital:7094 , http://hdl.handle.net/10962/d1012427
- Description: In many parts of the world clothes are washed near to or in rivers and streams. Little information is available on resulting concentrations of detergent ingredients or on any potential effects caused. In this study, the fate of a commonly used anionic surfactant, linear alkylbenzene sulphonate (LAS) was investigated in a reach of the Balfour River (Eastern Cape Province, South Africa) which was regularly used as a site for laundry activity. Samples of river water were collected upstream of the main washing site and at a number of locations downstream on several occasions in winter and summer. Sediment samples were also collected and analysed. In addition, a household survey was conducted to ascertain the amount of detergent used and the distribution of washing practices. The results of the survey suggested that the use of riverside locations for laundry activities was seasonal. Most washing tended to be done at home during the winter with riverside sites used more frequently during the summer months. The monitoring data showed that LAS concentrations in water were very variable. They were occasionally high in the immediate vicinity of the laundry site (up to 342 µg L− 1) but were generally very low (< 11 µg L− 1) at downstream monitoring stations, suggesting that LAS was rapidly dissipated by a combination of degradation, hydrodynamic dispersion and dilution. Concentrations in the immediate vicinity of the washing site were lower than expected on the basis of the household survey because most waste water was disposed of on the river bank rather than directly in the river. No ecological effects are expected from LAS emissions at this site.
- Full Text:
- Date Issued: 2009
- Authors: Gordon, Andrew K , Muller, Wilhelmine J , Gysman, N , Marshall, S J , Sparham, C J , O'Connor, S M , Whelan, M J
- Date: 2009
- Language: English
- Type: text , Article
- Identifier: vital:7094 , http://hdl.handle.net/10962/d1012427
- Description: In many parts of the world clothes are washed near to or in rivers and streams. Little information is available on resulting concentrations of detergent ingredients or on any potential effects caused. In this study, the fate of a commonly used anionic surfactant, linear alkylbenzene sulphonate (LAS) was investigated in a reach of the Balfour River (Eastern Cape Province, South Africa) which was regularly used as a site for laundry activity. Samples of river water were collected upstream of the main washing site and at a number of locations downstream on several occasions in winter and summer. Sediment samples were also collected and analysed. In addition, a household survey was conducted to ascertain the amount of detergent used and the distribution of washing practices. The results of the survey suggested that the use of riverside locations for laundry activities was seasonal. Most washing tended to be done at home during the winter with riverside sites used more frequently during the summer months. The monitoring data showed that LAS concentrations in water were very variable. They were occasionally high in the immediate vicinity of the laundry site (up to 342 µg L− 1) but were generally very low (< 11 µg L− 1) at downstream monitoring stations, suggesting that LAS was rapidly dissipated by a combination of degradation, hydrodynamic dispersion and dilution. Concentrations in the immediate vicinity of the washing site were lower than expected on the basis of the household survey because most waste water was disposed of on the river bank rather than directly in the river. No ecological effects are expected from LAS emissions at this site.
- Full Text:
- Date Issued: 2009
Review of the African distribution of the brine shrimp genus Artemia
- Kaiser, Horst, Gordon, Andrew K, Paulet, T G
- Authors: Kaiser, Horst , Gordon, Andrew K , Paulet, T G
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6765 , http://hdl.handle.net/10962/d1007963
- Description: Brine shrimp (genus Artemia) are small (8 to 12 mm long) cosmopolitan crustaceans (Anostraca) found predominately in hypersaline water bodies such as inland salt lakes and pans, coastal lagoons, and salt works at salinity levels above 40 g(.)l[superscript(-1)]. They have been extensively studied due to their high monetary value as food for larval fish in aquaculture and their unique reproductive strategies. Brine shrimp occur as either bisexual species or as parthenogenetic populations. Despite published reviews of their world-wide distribution little is known about their occurrence in Africa. This review adds new information about 70 African Artemia sites and lists 26 potential sites and their coordinates. Sixteen sites in Southern Africa and Namibia were visited during a collecting trip, and new information on the reproductive mode of nine of these sites is given. Several South African populations exhibit bisexual reproduction. In Namibia there are two parthenogenetic populations (Walvis Bay and Swartkops) and an additional bisexual population (Hentie's Bay). A mixed population (bisexual and parthenogenetic reproduction at the same site) was found at Coega, South Africa.
- Full Text:
- Date Issued: 2006
- Authors: Kaiser, Horst , Gordon, Andrew K , Paulet, T G
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6765 , http://hdl.handle.net/10962/d1007963
- Description: Brine shrimp (genus Artemia) are small (8 to 12 mm long) cosmopolitan crustaceans (Anostraca) found predominately in hypersaline water bodies such as inland salt lakes and pans, coastal lagoons, and salt works at salinity levels above 40 g(.)l[superscript(-1)]. They have been extensively studied due to their high monetary value as food for larval fish in aquaculture and their unique reproductive strategies. Brine shrimp occur as either bisexual species or as parthenogenetic populations. Despite published reviews of their world-wide distribution little is known about their occurrence in Africa. This review adds new information about 70 African Artemia sites and lists 26 potential sites and their coordinates. Sixteen sites in Southern Africa and Namibia were visited during a collecting trip, and new information on the reproductive mode of nine of these sites is given. Several South African populations exhibit bisexual reproduction. In Namibia there are two parthenogenetic populations (Walvis Bay and Swartkops) and an additional bisexual population (Hentie's Bay). A mixed population (bisexual and parthenogenetic reproduction at the same site) was found at Coega, South Africa.
- Full Text:
- Date Issued: 2006
The development of a toxicity database using freshwater macroinvertebrates, and its application to the protection of South African water resources
- Palmer, Carolyn G, Muller, Wilhelmine J, Gordon, Andrew K, Scherman, Patricia A, Davies-Coleman, Heather D, Pakhomova, L, de Kock, E
- Authors: Palmer, Carolyn G , Muller, Wilhelmine J , Gordon, Andrew K , Scherman, Patricia A , Davies-Coleman, Heather D , Pakhomova, L , de Kock, E
- Date: 2004
- Language: English
- Type: text , Article
- Identifier: vital:7073 , http://hdl.handle.net/10962/d1009528
- Description: There is a growing international trend towards the protection of freshwater resources from pollution by imposing instream guidelines and specified waste-discharge conditions. Current methods for devising freshwater quality guidelines are based on species sensitivity distributions (SSDs) that are used to identify pollutant concentrations, ensuring the protection of a modelled percentage of species (95% protection is a common goal). SSDs are derived from the toxicity test results of as many taxa as possible for each polluting substance. Waste-discharge licences can be for single substances, specified in terms of chemical concentrations, and derived in conjunction with instream guidelines; or for complex mixtures, specified in terms of toxic units. In both cases toxicity test results are the core data used. The emphasis on SSDs calls into question the species constituting the test populations. It is likely that SSDs based in part on the responses of local organisms will achieve superior site-specific ecological protection. Until the early 1990s, there were very few data on the tolerances of South African freshwater organisms. In the intervening decade, the Unilever Centre for Environmental Water Quality at Rhodes University has developed a toxicity database that, to date, records the responses of 21 South African freshwater taxa to 26 single-substance pollutants or mixtures. This is the most comprehensive database of South African toxicity responses available and has been used in the drawing up of methods and guidelines to protect water resources. This paper aims to make these data available and to describe applications of the data using selected case studies.
- Full Text:
- Date Issued: 2004
- Authors: Palmer, Carolyn G , Muller, Wilhelmine J , Gordon, Andrew K , Scherman, Patricia A , Davies-Coleman, Heather D , Pakhomova, L , de Kock, E
- Date: 2004
- Language: English
- Type: text , Article
- Identifier: vital:7073 , http://hdl.handle.net/10962/d1009528
- Description: There is a growing international trend towards the protection of freshwater resources from pollution by imposing instream guidelines and specified waste-discharge conditions. Current methods for devising freshwater quality guidelines are based on species sensitivity distributions (SSDs) that are used to identify pollutant concentrations, ensuring the protection of a modelled percentage of species (95% protection is a common goal). SSDs are derived from the toxicity test results of as many taxa as possible for each polluting substance. Waste-discharge licences can be for single substances, specified in terms of chemical concentrations, and derived in conjunction with instream guidelines; or for complex mixtures, specified in terms of toxic units. In both cases toxicity test results are the core data used. The emphasis on SSDs calls into question the species constituting the test populations. It is likely that SSDs based in part on the responses of local organisms will achieve superior site-specific ecological protection. Until the early 1990s, there were very few data on the tolerances of South African freshwater organisms. In the intervening decade, the Unilever Centre for Environmental Water Quality at Rhodes University has developed a toxicity database that, to date, records the responses of 21 South African freshwater taxa to 26 single-substance pollutants or mixtures. This is the most comprehensive database of South African toxicity responses available and has been used in the drawing up of methods and guidelines to protect water resources. This paper aims to make these data available and to describe applications of the data using selected case studies.
- Full Text:
- Date Issued: 2004
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