A new gobiid fish, Fusigobius duospilus, from the tropical Indo-Pacific
- Hoese, Douglass F, Reader, Sally, J.L.B. Smith Institute of Ichthyology
- Authors: Hoese, Douglass F , Reader, Sally , J.L.B. Smith Institute of Ichthyology
- Date: 1985-01
- Subjects: Gobiidae -- Classification
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/70180 , vital:29631 , Margaret Smith Library (South African Institute for Aquatic Biodiversity (SAIAB)) Periodicals Margaret Smith Library (South African Institute for Aquatic Biodiversity (SAIAB))
- Description: Online version of original print edition of the Special Publication of the J.L.B. Smith Institute of Ichthyology; No. 36 , Fusigobius duospilusis described as a new species from several localities in the tropical Pacific and Indian oceans. This species differs from other species of Fusigobius in pectoral ray and gill-raker counts, coloration, reduced pelvic frenum, branching of the pelvic rays, presence of two large black spots on the first dorsal fin and shape of the first dorsal fin. The species is free living on sand. Males average a larger size than females. Sex ratios are uneven, with about twice as many females as males. Fusigobius longispinus Goren is recorded from several localities in the western Indian Ocean, where populations differ morphologically from Red Sea populations. Fusiogobius neophytus africanusls regarded as a synonym of F. neophytus.
- Full Text:
- Date Issued: 1985-01
- Authors: Hoese, Douglass F , Reader, Sally , J.L.B. Smith Institute of Ichthyology
- Date: 1985-01
- Subjects: Gobiidae -- Classification
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/70180 , vital:29631 , Margaret Smith Library (South African Institute for Aquatic Biodiversity (SAIAB)) Periodicals Margaret Smith Library (South African Institute for Aquatic Biodiversity (SAIAB))
- Description: Online version of original print edition of the Special Publication of the J.L.B. Smith Institute of Ichthyology; No. 36 , Fusigobius duospilusis described as a new species from several localities in the tropical Pacific and Indian oceans. This species differs from other species of Fusigobius in pectoral ray and gill-raker counts, coloration, reduced pelvic frenum, branching of the pelvic rays, presence of two large black spots on the first dorsal fin and shape of the first dorsal fin. The species is free living on sand. Males average a larger size than females. Sex ratios are uneven, with about twice as many females as males. Fusigobius longispinus Goren is recorded from several localities in the western Indian Ocean, where populations differ morphologically from Red Sea populations. Fusiogobius neophytus africanusls regarded as a synonym of F. neophytus.
- Full Text:
- Date Issued: 1985-01
Developmental Psychology, Psychological Testing & Assessment, Research Methods: PSY 222
- Authors: Marais, R , Hoho, V N
- Date: 2012-01
- Language: English
- Type: Examination paper
- Identifier: vital:18014 , http://hdl.handle.net/10353/d1010591
- Description: Developmental Psychology, Psychological Testing & Assessment, Research Methods: PSY 222, Supplementary examination January 2012.
- Full Text: false
- Date Issued: 2012-01
- Authors: Marais, R , Hoho, V N
- Date: 2012-01
- Language: English
- Type: Examination paper
- Identifier: vital:18014 , http://hdl.handle.net/10353/d1010591
- Description: Developmental Psychology, Psychological Testing & Assessment, Research Methods: PSY 222, Supplementary examination January 2012.
- Full Text: false
- Date Issued: 2012-01
Adult African sharptooth catfish, Clarias gariepinus, population dynamics in a small invaded warm-temperate impoundment
- Booth, Anthony J, Traas, Graham R L, Weyl, Olaf L F
- Authors: Booth, Anthony J , Traas, Graham R L , Weyl, Olaf L F
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123596 , vital:35461 , https://doi.10.3377/004.045.0208
- Description: African sharptooth catfish, Clarias gariepinus (Burchell 1822), is a potamodromous species that is naturally distributed from Turkey to the Orange River, South Africa (Skelton 1993). It is omnivorous, feeding on plankton, vegetation, invertebrates, carrion and fish (de Moor & Bruton 1988) and may exhibit pack-hunting behaviour when foraging for small fish (Bruton 1979; Merron 1993). Clarias gariepinus is a large (>150 cm TL, >30 kg; Bruton 1976), long-lived (validated to at least 15 years, Weyl & Booth 2008) and fast-growing (Bruton & Allanson 1980; Quick & Bruton 1984; Richardson et al. 2009) fish that attains sexual maturity within two years of age (de Moor & Bruton 1988). It is eurythermic (80–35°C), mesohalic (0–10 ppt) and has the ability to airbreathe. These attributes predispose it to surviving in all but the most adverse of conditions and have directly contributed to its wide use as an aquaculture species. These attributes have also contributed to its ability to invade waterbodies beyond its natural range (de Moor & Bruton 1988) and after inadvertent introductions such as by escape from aquaculture facilities or through water transfer schemes, C. gariepinus has established populations in many non-native environments. Such invasions include the Philippines (Mercene 1997), Bangladesh (Arthur & Ahmed 2002), Thailand (Vidthayanon 2005), India (Bhakta & Bandyopadhyay 2007) and Brazil (Cambray 2005; Vitule et al. 2006; Rocha & Schiavetti 2007). In South Africa, C. gariepinus invaded the temperate Great Fish River catchment after the species was translocated from the Orange River through a Interbasin Water Transfer (IBWT) scheme (Laurenson et al. 1989). Potential threats include predation of and competition with indigenous species, habitat degradation, and the spread of diseases and parasites (Dudgeon et al. 2006).
- Full Text:
- Date Issued: 2010
- Authors: Booth, Anthony J , Traas, Graham R L , Weyl, Olaf L F
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123596 , vital:35461 , https://doi.10.3377/004.045.0208
- Description: African sharptooth catfish, Clarias gariepinus (Burchell 1822), is a potamodromous species that is naturally distributed from Turkey to the Orange River, South Africa (Skelton 1993). It is omnivorous, feeding on plankton, vegetation, invertebrates, carrion and fish (de Moor & Bruton 1988) and may exhibit pack-hunting behaviour when foraging for small fish (Bruton 1979; Merron 1993). Clarias gariepinus is a large (>150 cm TL, >30 kg; Bruton 1976), long-lived (validated to at least 15 years, Weyl & Booth 2008) and fast-growing (Bruton & Allanson 1980; Quick & Bruton 1984; Richardson et al. 2009) fish that attains sexual maturity within two years of age (de Moor & Bruton 1988). It is eurythermic (80–35°C), mesohalic (0–10 ppt) and has the ability to airbreathe. These attributes predispose it to surviving in all but the most adverse of conditions and have directly contributed to its wide use as an aquaculture species. These attributes have also contributed to its ability to invade waterbodies beyond its natural range (de Moor & Bruton 1988) and after inadvertent introductions such as by escape from aquaculture facilities or through water transfer schemes, C. gariepinus has established populations in many non-native environments. Such invasions include the Philippines (Mercene 1997), Bangladesh (Arthur & Ahmed 2002), Thailand (Vidthayanon 2005), India (Bhakta & Bandyopadhyay 2007) and Brazil (Cambray 2005; Vitule et al. 2006; Rocha & Schiavetti 2007). In South Africa, C. gariepinus invaded the temperate Great Fish River catchment after the species was translocated from the Orange River through a Interbasin Water Transfer (IBWT) scheme (Laurenson et al. 1989). Potential threats include predation of and competition with indigenous species, habitat degradation, and the spread of diseases and parasites (Dudgeon et al. 2006).
- Full Text:
- Date Issued: 2010
“Face the music!”: the Daily Sun's representation of adolescent sex in the Jules High sex scandal
- Boshoff, Priscilla A, Prinsloo, Jeanne
- Authors: Boshoff, Priscilla A , Prinsloo, Jeanne
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143483 , vital:38250 , DOI: 10.1080/10130950.2013.834660
- Description: Rather than being merely a physiological stage, adolescence is variously constructed through social institutions. The media plays a significant role in such constructions, including that of adolescent sexuality. In the recent past there have been several cases of sexual acts involving adolescents that have received prominent media coverage as they have been considered shocking. The Jules High School sex scandal related to sex acts between a single adolescent girl and two adolescent boys. It was recorded on mobile phones by their peers and circulated on their mobile networks, or ‘went viral’ as the media continuously noted. The press coverage surrounding this incident and the legal process that ensued is the focus of this Article which undertakes a critical textual analysis of the coverage in the popular tabloid, the Daily Sun, in order to make explicit the contesting sets of discourses around adolescence and sexuality that were articulated in this popular public sphere. The Article uses a Foucauldian framework in order to probe the discourses of sexuality that are articulated and contested in this space. As the most widely read newspaper in South Africa it serves as a powerful site of definition of teen sexuality. The analysis suggests that, rather than allowing for teen sexuality, it is disavowed by villainising teen sex and responsibility for such ‘deviance’ is directed to various adult and social adult actors.
- Full Text:
- Date Issued: 2013
- Authors: Boshoff, Priscilla A , Prinsloo, Jeanne
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143483 , vital:38250 , DOI: 10.1080/10130950.2013.834660
- Description: Rather than being merely a physiological stage, adolescence is variously constructed through social institutions. The media plays a significant role in such constructions, including that of adolescent sexuality. In the recent past there have been several cases of sexual acts involving adolescents that have received prominent media coverage as they have been considered shocking. The Jules High School sex scandal related to sex acts between a single adolescent girl and two adolescent boys. It was recorded on mobile phones by their peers and circulated on their mobile networks, or ‘went viral’ as the media continuously noted. The press coverage surrounding this incident and the legal process that ensued is the focus of this Article which undertakes a critical textual analysis of the coverage in the popular tabloid, the Daily Sun, in order to make explicit the contesting sets of discourses around adolescence and sexuality that were articulated in this popular public sphere. The Article uses a Foucauldian framework in order to probe the discourses of sexuality that are articulated and contested in this space. As the most widely read newspaper in South Africa it serves as a powerful site of definition of teen sexuality. The analysis suggests that, rather than allowing for teen sexuality, it is disavowed by villainising teen sex and responsibility for such ‘deviance’ is directed to various adult and social adult actors.
- Full Text:
- Date Issued: 2013
Problems in rural transformation in South Africa specifically in the land reform arena:
- Antrobus, Geoffrey G, Fraser, Gavin C G, Tapson, D R
- Authors: Antrobus, Geoffrey G , Fraser, Gavin C G , Tapson, D R
- Date: 1998
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143035 , vital:38195 , https://www.infona.pl/resource/bwmeta1.element.agro-article-dc77672d-7269-4641-bf99-605eaa5fe369
- Description: Problems in rural transformation in South Africa specifically in the land reform arena
- Full Text:
- Date Issued: 1998
- Authors: Antrobus, Geoffrey G , Fraser, Gavin C G , Tapson, D R
- Date: 1998
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143035 , vital:38195 , https://www.infona.pl/resource/bwmeta1.element.agro-article-dc77672d-7269-4641-bf99-605eaa5fe369
- Description: Problems in rural transformation in South Africa specifically in the land reform arena
- Full Text:
- Date Issued: 1998
Assessment of the long-term response to rehabilitation of two wetlands in KwaZulu-Natal, South Africa:
- Cowden, Craig, Kotze, Donovan C, Ellery, William F N, Sieben, E J J
- Authors: Cowden, Craig , Kotze, Donovan C , Ellery, William F N , Sieben, E J J
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/144431 , vital:38345 , DOI: 10.2989/16085914.2014.954518
- Description: Assessing the ecological outcomes of wetland rehabilitation activities is an important need recognised by the ‘Working for Wetlands’ programme in South Africa. An assessment of ecological response was conducted in the Killarney and Kruisfontein wetlands, KwaZulu-Natal, in 2005 prior to rehabilitation in 2006, and again in 2011 and 2012, respectively, following rehabilitation. The assessment criteria included an evaluation of changes in ecological integrity, the supply of ecosystem services, and vegetation composition. Improvements in hydrological and geomorphic integrity were recorded in both wetlands, resulting in improved ecosystem delivery.
- Full Text:
- Date Issued: 2014
- Authors: Cowden, Craig , Kotze, Donovan C , Ellery, William F N , Sieben, E J J
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/144431 , vital:38345 , DOI: 10.2989/16085914.2014.954518
- Description: Assessing the ecological outcomes of wetland rehabilitation activities is an important need recognised by the ‘Working for Wetlands’ programme in South Africa. An assessment of ecological response was conducted in the Killarney and Kruisfontein wetlands, KwaZulu-Natal, in 2005 prior to rehabilitation in 2006, and again in 2011 and 2012, respectively, following rehabilitation. The assessment criteria included an evaluation of changes in ecological integrity, the supply of ecosystem services, and vegetation composition. Improvements in hydrological and geomorphic integrity were recorded in both wetlands, resulting in improved ecosystem delivery.
- Full Text:
- Date Issued: 2014
13C pulse-chase labeling comparative assessment of the active methanogenic archaeal community composition in the transgenic and nontransgenic parental rice rhizospheres
- Zhu, Weijing, Lu, Haohao, Hill, Jaclyn M, Wang, Hailong, Wu, Weixiang
- Authors: Zhu, Weijing , Lu, Haohao , Hill, Jaclyn M , Wang, Hailong , Wu, Weixiang
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/122993 , vital:35389 , https://doi.org/10.1111/1574-6941.12261
- Description: Rhabdosargus holubi (Steindachner, 1881) is a small (maximum size = 450 mm total length; Heemstra and Heemstra 2004) sparid that is distributed along the south-east coast of Africa from St Helena Bay, South Africa, to Maputo, Mozambique (Götz and Cowley 2013). Spawning occurs in the nearshore marine environment primarily during winter, specifically May–August in KwaZulu-Natal (KZN) (Wallace 1975) and July–February in the South-Eastern Cape (Whitfield 1998). Individuals reach 50% sexual maturity at approximately 150 mm standard length (SL) in the Eastern Cape (Whitfield 1998). The early life stages are transported by the south-westward-flowing Agulhas Current, and recruit as post-flexion larvae and early juveniles into estuaries during late winter and early summer (Blaber 1974). The warm temperatures and high nutrient levels in estuaries favour fast growth (Blaber 1973a), and fish spend their first year of life in these environments, migrating back out to sea after reaching approximately 120 mm SL. Some individuals remain trapped in closed estuaries, where they may reach sizes greater than 200 mm SL (James et al. 2007a). Rhabdosargus holubi is the dominant estuarine-dependent marine teleost species recorded in permanently open and temporarily open/closed estuaries in the warm-temperate region, which spans the south, south-east and east coast of South Africa (Harrison 2005). The species is also an important component of the linefishery in many SouthAfrican estuaries (10–15.6% by number) (Pradervand and Baird 2002), particularly in Eastern Cape estuaries (Cowley et al. 2003). These figures underestimate the presence of R. holubi, as most individuals making use of estuaries are young, feeding predominately on filamentous macroalgae and diatom flora, and are generally too small to be caught with hook and line (De Wet and Marais 1990). James et al. (2007b) showed that R. holubi made up 34–92% of the annual seine-net catch in the East Kleinemonde Estuary. Rhabdosargus holubi is also important in the KZN shorebased linefishery, representing 4.6% of the total landed catch (Dunlop and Mann 2012)More and more investigations indicate that genetic modification has no significant or persistent effects on microbial community composition in the rice rhizosphere. Very few studies, however, have focused on its impact on functional microorganisms. This study completed a 13C-CO2 pulse-chase labeling experiment comparing the potential effects of cry1Ab gene transformation on 13C tissue distribution and rhizosphere methanogenic archaeal community composition with its parental rice variety (Ck) and a distant parental rice variety (Dp). Results showed that 13C partitioning in aboveground biomass (mainly in stems) and roots of Dp was significantly lower than that of Ck. However, there were no significant differences in 13C partitioning between the Bt transgenic rice line (Bt) and Ck. RNA-stable isotope probing combined with clone library analyses inferred that the group Methanosaetaceae was the predominant methanogenic Archaea in all three rice rhizospheres. The active methanogenic archaeal community in the Bt rhizosphere was dominated by Methanosarcinaceae, Methanosaetaceae, and Methanomicrobiaceae, while there were only two main methanogenic clusters (Methanosaetaceae and Methanomicrobiaceae) in the Ck and Dp rhizospheres. These results indicate that the insertion of cry1Ab gene into the rice genome has the potential to result in the modification of methanogenic community composition in its rhizosphere.
- Full Text:
- Date Issued: 2013
- Authors: Zhu, Weijing , Lu, Haohao , Hill, Jaclyn M , Wang, Hailong , Wu, Weixiang
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/122993 , vital:35389 , https://doi.org/10.1111/1574-6941.12261
- Description: Rhabdosargus holubi (Steindachner, 1881) is a small (maximum size = 450 mm total length; Heemstra and Heemstra 2004) sparid that is distributed along the south-east coast of Africa from St Helena Bay, South Africa, to Maputo, Mozambique (Götz and Cowley 2013). Spawning occurs in the nearshore marine environment primarily during winter, specifically May–August in KwaZulu-Natal (KZN) (Wallace 1975) and July–February in the South-Eastern Cape (Whitfield 1998). Individuals reach 50% sexual maturity at approximately 150 mm standard length (SL) in the Eastern Cape (Whitfield 1998). The early life stages are transported by the south-westward-flowing Agulhas Current, and recruit as post-flexion larvae and early juveniles into estuaries during late winter and early summer (Blaber 1974). The warm temperatures and high nutrient levels in estuaries favour fast growth (Blaber 1973a), and fish spend their first year of life in these environments, migrating back out to sea after reaching approximately 120 mm SL. Some individuals remain trapped in closed estuaries, where they may reach sizes greater than 200 mm SL (James et al. 2007a). Rhabdosargus holubi is the dominant estuarine-dependent marine teleost species recorded in permanently open and temporarily open/closed estuaries in the warm-temperate region, which spans the south, south-east and east coast of South Africa (Harrison 2005). The species is also an important component of the linefishery in many SouthAfrican estuaries (10–15.6% by number) (Pradervand and Baird 2002), particularly in Eastern Cape estuaries (Cowley et al. 2003). These figures underestimate the presence of R. holubi, as most individuals making use of estuaries are young, feeding predominately on filamentous macroalgae and diatom flora, and are generally too small to be caught with hook and line (De Wet and Marais 1990). James et al. (2007b) showed that R. holubi made up 34–92% of the annual seine-net catch in the East Kleinemonde Estuary. Rhabdosargus holubi is also important in the KZN shorebased linefishery, representing 4.6% of the total landed catch (Dunlop and Mann 2012)More and more investigations indicate that genetic modification has no significant or persistent effects on microbial community composition in the rice rhizosphere. Very few studies, however, have focused on its impact on functional microorganisms. This study completed a 13C-CO2 pulse-chase labeling experiment comparing the potential effects of cry1Ab gene transformation on 13C tissue distribution and rhizosphere methanogenic archaeal community composition with its parental rice variety (Ck) and a distant parental rice variety (Dp). Results showed that 13C partitioning in aboveground biomass (mainly in stems) and roots of Dp was significantly lower than that of Ck. However, there were no significant differences in 13C partitioning between the Bt transgenic rice line (Bt) and Ck. RNA-stable isotope probing combined with clone library analyses inferred that the group Methanosaetaceae was the predominant methanogenic Archaea in all three rice rhizospheres. The active methanogenic archaeal community in the Bt rhizosphere was dominated by Methanosarcinaceae, Methanosaetaceae, and Methanomicrobiaceae, while there were only two main methanogenic clusters (Methanosaetaceae and Methanomicrobiaceae) in the Ck and Dp rhizospheres. These results indicate that the insertion of cry1Ab gene into the rice genome has the potential to result in the modification of methanogenic community composition in its rhizosphere.
- Full Text:
- Date Issued: 2013
A review of estuarine ichthyology in South Africa over the past 50 years
- Authors: Whitfield, A K
- Date: 1996
- Language: English
- Type: text , Article
- Identifier: vital:7155 , http://hdl.handle.net/10962/d1011873
- Description: Progress in South African estuarine ichthyology between 1946 and 1995 is reviewed. The early estuary surveys of the 1950s and 1960s resulted in the compilation of species lists for individual systems, but contained very little biological or ecological information on fishes. These surveys were superseded by both autecological and synecological studies in the 1970s and 1980s, which yielded descriptive and process-orientated information on a wide variety of species. Estuarine research during the 1990s has focused increasingly at the community level, with several review papers on the life-history styles of groups of estuarine-associated fishes being published. The last decade has also seen the departure of a number of senior estuarine ichthyologists from the field. This decline in available expertise has coincided with increased demand for ichthyological information to be used in decision support systems for the wise management and conservation of estuaries. It is suggested that these demands be seen as a challenge, with studies being directed towards providing the type of information needed for the maintenance of vital ecological processes within these systems.
- Full Text: false
- Date Issued: 1996
- Authors: Whitfield, A K
- Date: 1996
- Language: English
- Type: text , Article
- Identifier: vital:7155 , http://hdl.handle.net/10962/d1011873
- Description: Progress in South African estuarine ichthyology between 1946 and 1995 is reviewed. The early estuary surveys of the 1950s and 1960s resulted in the compilation of species lists for individual systems, but contained very little biological or ecological information on fishes. These surveys were superseded by both autecological and synecological studies in the 1970s and 1980s, which yielded descriptive and process-orientated information on a wide variety of species. Estuarine research during the 1990s has focused increasingly at the community level, with several review papers on the life-history styles of groups of estuarine-associated fishes being published. The last decade has also seen the departure of a number of senior estuarine ichthyologists from the field. This decline in available expertise has coincided with increased demand for ichthyological information to be used in decision support systems for the wise management and conservation of estuaries. It is suggested that these demands be seen as a challenge, with studies being directed towards providing the type of information needed for the maintenance of vital ecological processes within these systems.
- Full Text: false
- Date Issued: 1996
Integrating Ecosystem Services and Disservices in Valuing Smallholder Livestock and Poultry Production in Three Villages in South Africa
- Herd-Hoare, Shannon C, Shackleton, Charlie M
- Authors: Herd-Hoare, Shannon C , Shackleton, Charlie M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/176089 , vital:42659 , https://doi.org/10.1016/j.ufug.2020.126740 , https://doi.org/10.21504/RUR.c.5388515.v1
- Description: This study presents an integrated examination of both the ecosystem services (ES) and ecosystem disservices (EDS) associated with smallholder animal husbandry in rural livelihoods in three villages in southeast South Africa. It recognises the contribution of ES supporting and resulting from smallholder livestock and poultry production, but also details the limiting factors or EDS, such as tick-borne disease, birds of prey or unpalatable rangeland, produced by the same system. Using a mixed-methods approach, including focus group discussions with various Participatory Learning and Action (PLA) activities, key informant interviews, household surveys and land-use change mapping on GIS, we consider the relative value and benefits from ES after the effects of EDS, as well as the management and strategies that households adopt to minimise EDS.
- Full Text:
- Date Issued: 2020
- Authors: Herd-Hoare, Shannon C , Shackleton, Charlie M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/176089 , vital:42659 , https://doi.org/10.1016/j.ufug.2020.126740 , https://doi.org/10.21504/RUR.c.5388515.v1
- Description: This study presents an integrated examination of both the ecosystem services (ES) and ecosystem disservices (EDS) associated with smallholder animal husbandry in rural livelihoods in three villages in southeast South Africa. It recognises the contribution of ES supporting and resulting from smallholder livestock and poultry production, but also details the limiting factors or EDS, such as tick-borne disease, birds of prey or unpalatable rangeland, produced by the same system. Using a mixed-methods approach, including focus group discussions with various Participatory Learning and Action (PLA) activities, key informant interviews, household surveys and land-use change mapping on GIS, we consider the relative value and benefits from ES after the effects of EDS, as well as the management and strategies that households adopt to minimise EDS.
- Full Text:
- Date Issued: 2020
Emergent effects of structural complexity and temperature on predator–prey interactions
- Wasserman, Ryan J, Alexander, Mhairi E, Weyl, Olaf L F, Barrios‐O'Neill, Daniel, Froneman, P William, Dalu, Tatenda
- Authors: Wasserman, Ryan J , Alexander, Mhairi E , Weyl, Olaf L F , Barrios‐O'Neill, Daniel , Froneman, P William , Dalu, Tatenda
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/69190 , vital:29444 , https://doi.org/10.1002/ecs2.1239
- Description: Ephemeral aquatic environments are important habitats for a variety of species. They are highly variable with regards to vegetation structure and physico‐chemical features that potentially mediate outcomes of biotic interactions. Multiple environmental variables and their emergent impacts on the relationship between prey consumption rate by a predator and prey density (functional response), however, are rarely assessed. Here, we investigated the combined effects of temperature and habitat complexity on the functional response of the freshwater predatory notonectid Enithares sobria on the cladoceran prey organism Daphnia longispina. A Type II functional response was observed for E. sobria predating on D. longispina and while temperature and habitat complexity had no effect on the response type, these environmental variables interacted with consequences for the magnitude of the functional responses. Overall, structural complexity favored the predator as greater consumption was observed in the most complex habitat treatment. Temperature effects were also evident although these effects were not unidirectional with regard to treatment factor gradients as predators were the most successful at intermediary temperatures. Furthermore, there was a complex interplay between habitat complexity and temperature, with attack rates being greatest at low and high complexities within intermediate temperatures, while at zero complexity attack rates were greatest at the lowest temperature. The effect of habitat on handling times was only evident in the low temperature treatments which decreased steadily with each increase in complexity. Through the application of functional responses the synergistic effects of multiple environmental drivers on predator–prey interaction outcomes have been highlighted, adding insight into how interactions among species may be affected by natural or artificially induced environmental variability.
- Full Text:
- Date Issued: 2016
- Authors: Wasserman, Ryan J , Alexander, Mhairi E , Weyl, Olaf L F , Barrios‐O'Neill, Daniel , Froneman, P William , Dalu, Tatenda
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/69190 , vital:29444 , https://doi.org/10.1002/ecs2.1239
- Description: Ephemeral aquatic environments are important habitats for a variety of species. They are highly variable with regards to vegetation structure and physico‐chemical features that potentially mediate outcomes of biotic interactions. Multiple environmental variables and their emergent impacts on the relationship between prey consumption rate by a predator and prey density (functional response), however, are rarely assessed. Here, we investigated the combined effects of temperature and habitat complexity on the functional response of the freshwater predatory notonectid Enithares sobria on the cladoceran prey organism Daphnia longispina. A Type II functional response was observed for E. sobria predating on D. longispina and while temperature and habitat complexity had no effect on the response type, these environmental variables interacted with consequences for the magnitude of the functional responses. Overall, structural complexity favored the predator as greater consumption was observed in the most complex habitat treatment. Temperature effects were also evident although these effects were not unidirectional with regard to treatment factor gradients as predators were the most successful at intermediary temperatures. Furthermore, there was a complex interplay between habitat complexity and temperature, with attack rates being greatest at low and high complexities within intermediate temperatures, while at zero complexity attack rates were greatest at the lowest temperature. The effect of habitat on handling times was only evident in the low temperature treatments which decreased steadily with each increase in complexity. Through the application of functional responses the synergistic effects of multiple environmental drivers on predator–prey interaction outcomes have been highlighted, adding insight into how interactions among species may be affected by natural or artificially induced environmental variability.
- Full Text:
- Date Issued: 2016
Development of a stability-indicating high performance liquid chromatographic method for the analysis of topiramate and dissolution rate testing in topiramate tablets
- Mohammadi, Ali, Rezanour, Nasrin, Ansari Dogaheh, M, Walker, Roderick B
- Authors: Mohammadi, Ali , Rezanour, Nasrin , Ansari Dogaheh, M , Walker, Roderick B
- Date: 2010
- Language: English
- Type: text , Article
- Identifier: vital:6412 , http://hdl.handle.net/10962/d1006507
- Description: A stability-indicating high performance liquid chromatographic(HPLC) method was developed and validated for the quantitation and dissolution determination of topiramate in tablet dosage forms. An isocratic separation was achieved using a phenyl column with a flow rate of 1 mL/min using UV detection at 264 nm. Topiramate has low UV absorbtivity and was subjected to derivatization with 9-fluorenylmethyl chloroformate (FMOC-Cl). The mobile phase for the separation consisted of acetonitrile: 50 mM sodium dihydrogen phosphate(NaH2PO4) containing 3 % v/v triethylamine (pH 2.8) in a 48:52 v/v ratio. Topiramate was subjected to oxidation, hydrolysis, photolysis and heat for the purposes of stress testing. Separation was achieved for the parent compound and all the degradation products in an overall analytical run time of approximately 15 min with the parent compound topiramate eluting at approximately 9.2 min. The method was linear over the concentration range of 1-100 μg/mL (r = 0.9996) with limits of quantitation and detection of 1 and 0.3 μg/mL, respectively.
- Full Text:
- Date Issued: 2010
- Authors: Mohammadi, Ali , Rezanour, Nasrin , Ansari Dogaheh, M , Walker, Roderick B
- Date: 2010
- Language: English
- Type: text , Article
- Identifier: vital:6412 , http://hdl.handle.net/10962/d1006507
- Description: A stability-indicating high performance liquid chromatographic(HPLC) method was developed and validated for the quantitation and dissolution determination of topiramate in tablet dosage forms. An isocratic separation was achieved using a phenyl column with a flow rate of 1 mL/min using UV detection at 264 nm. Topiramate has low UV absorbtivity and was subjected to derivatization with 9-fluorenylmethyl chloroformate (FMOC-Cl). The mobile phase for the separation consisted of acetonitrile: 50 mM sodium dihydrogen phosphate(NaH2PO4) containing 3 % v/v triethylamine (pH 2.8) in a 48:52 v/v ratio. Topiramate was subjected to oxidation, hydrolysis, photolysis and heat for the purposes of stress testing. Separation was achieved for the parent compound and all the degradation products in an overall analytical run time of approximately 15 min with the parent compound topiramate eluting at approximately 9.2 min. The method was linear over the concentration range of 1-100 μg/mL (r = 0.9996) with limits of quantitation and detection of 1 and 0.3 μg/mL, respectively.
- Full Text:
- Date Issued: 2010
Towards reconciliation of structure with function in plasmodesmata—who is the gatekeeper?
- Botha, Christiaan E J, Cross, Robin H M
- Authors: Botha, Christiaan E J , Cross, Robin H M
- Date: 2000
- Language: English
- Type: Article
- Identifier: vital:6497 , http://hdl.handle.net/10962/d1004493
- Description: Whilst the structure of higher plant plasmodesmata was first described by Robards (1963. Desmotubule—a plasmodesmatal substructure. Nature 218, 784), and despite many subsequent intensive investigations, there is still much that remains unclear relating to their ultrastructure and functioning in higher plants. We have examined chemically fixed plant material, and suggest that the conformational changes seen in plasmodesmatal substructure, particularly the deposition of electron-dense extra-plasmodesmal material, is linked to either manipulation of the hormonal balance (as in Avocado fruit), or of osmotic potential in leaf blade material. These changes result in the deposition of β 1,3-glucan (callose) at the neck region of these plasmodesmata. This electron-dense material is deposited at the neck region of plasmodesmata, and forms a collar-like structure. The formation of a collar is shown to be coupled with loss of lucence within the cytoplasmic sleeve. The formation of a collar at the plasmodesmatal orifice thus results in encapsulation and closure of the plasmodesmatal orifice. Closure of the orifice coincides with a loss of electron-lucence and a lack of resolution of the desmotubule. These ultrastructural changes are potentially significant and could contribute to, result in, or assist in the down-regulation of cell to cell trafficking via plasmodesmata.
- Full Text:
- Date Issued: 2000
- Authors: Botha, Christiaan E J , Cross, Robin H M
- Date: 2000
- Language: English
- Type: Article
- Identifier: vital:6497 , http://hdl.handle.net/10962/d1004493
- Description: Whilst the structure of higher plant plasmodesmata was first described by Robards (1963. Desmotubule—a plasmodesmatal substructure. Nature 218, 784), and despite many subsequent intensive investigations, there is still much that remains unclear relating to their ultrastructure and functioning in higher plants. We have examined chemically fixed plant material, and suggest that the conformational changes seen in plasmodesmatal substructure, particularly the deposition of electron-dense extra-plasmodesmal material, is linked to either manipulation of the hormonal balance (as in Avocado fruit), or of osmotic potential in leaf blade material. These changes result in the deposition of β 1,3-glucan (callose) at the neck region of these plasmodesmata. This electron-dense material is deposited at the neck region of plasmodesmata, and forms a collar-like structure. The formation of a collar is shown to be coupled with loss of lucence within the cytoplasmic sleeve. The formation of a collar at the plasmodesmatal orifice thus results in encapsulation and closure of the plasmodesmatal orifice. Closure of the orifice coincides with a loss of electron-lucence and a lack of resolution of the desmotubule. These ultrastructural changes are potentially significant and could contribute to, result in, or assist in the down-regulation of cell to cell trafficking via plasmodesmata.
- Full Text:
- Date Issued: 2000
A Case Study of Two Selected Teachers as they Integrated Dynamic Geometry Software as a Visualisation Tool in Teaching Geometry:
- Mavani, Deepak, Mavani, Beena, Schäfer, Marc
- Authors: Mavani, Deepak , Mavani, Beena , Schäfer, Marc
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141076 , vital:37942 , https://doi.org/10.1080/18117295.2018.1522716
- Description: This paper reports on an aspect of a larger research study conceptualised within a teacher development project in Mthatha, Eastern Cape Province. The project was initiated with the objective to develop appropriate skills to use dynamic geometry software (DGS) effectively and strategically as a teaching and learning tool for mathematics. The study reported in this paper aims specifically to ascertain how selected mathematics teachers integrated co-developed technologically aided visualisation tools in the observed lessons. The case study involved two teachers from different schools. The data sources were the classroom observations followed by stimulated reflective interviews with the teachers. The data were analysed to study the use of DGS visualisation tools in relation to Kilpatrick’s framework of teaching proficiency.
- Full Text:
- Date Issued: 2018
- Authors: Mavani, Deepak , Mavani, Beena , Schäfer, Marc
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141076 , vital:37942 , https://doi.org/10.1080/18117295.2018.1522716
- Description: This paper reports on an aspect of a larger research study conceptualised within a teacher development project in Mthatha, Eastern Cape Province. The project was initiated with the objective to develop appropriate skills to use dynamic geometry software (DGS) effectively and strategically as a teaching and learning tool for mathematics. The study reported in this paper aims specifically to ascertain how selected mathematics teachers integrated co-developed technologically aided visualisation tools in the observed lessons. The case study involved two teachers from different schools. The data sources were the classroom observations followed by stimulated reflective interviews with the teachers. The data were analysed to study the use of DGS visualisation tools in relation to Kilpatrick’s framework of teaching proficiency.
- Full Text:
- Date Issued: 2018
6-Hydroxymelatonin protects against cyanide induced oxidative stress in rat brain homogenates
- Maharaj, Deepa S, Walker, Roderick B, Glass, Beverley D, Daya, Santylal
- Authors: Maharaj, Deepa S , Walker, Roderick B , Glass, Beverley D , Daya, Santylal
- Date: 2003
- Language: English
- Type: Article , text
- Identifier: vital:6405 , http://hdl.handle.net/10962/d1006478
- Description: Both 6-hydroxymelatonin and N-acetyl-N-formyl-5-methoxykynurenamine are photodegradants and enzymatic metabolites of melatonin and are known to retain equipotent activity against potassium cyanide-induced superoxide generation compared to melatonin. It is not clear whether one or both of these metabolites is responsible for this effect. The present study therefore investigates the possible manner in which 6-hydroxymelatonin protects against oxidative stress induced by cyanide in rat brain homogenates. We examined the ability of 6-hydroxymelatonin to scavenge KCN-induced superoxide anion generation as well as lipid peroxidation. In addition, we also examined the effect of this indole on lactate dehydrogenase activity (LDH) as well as mitochondrial electron transport using dichlorophenol–indophenol as an electron acceptor. The results of this study show that 6-hydroxymelatonin significantly reduces KCN-induced superoxide anion generation, which is accompanied by a commensurate reduction in lipid peroxidation. Partial reversal of the KCN-induced reduction in mitochondrial electron transport is accompanied by a similar reversal of mitochondrial LDH activity blunted by KCN. It can thus be proposed that 6-hydroxymelatonin is potentially neuroprotective against KCN-induced neurotoxicity.
- Full Text:
- Date Issued: 2003
- Authors: Maharaj, Deepa S , Walker, Roderick B , Glass, Beverley D , Daya, Santylal
- Date: 2003
- Language: English
- Type: Article , text
- Identifier: vital:6405 , http://hdl.handle.net/10962/d1006478
- Description: Both 6-hydroxymelatonin and N-acetyl-N-formyl-5-methoxykynurenamine are photodegradants and enzymatic metabolites of melatonin and are known to retain equipotent activity against potassium cyanide-induced superoxide generation compared to melatonin. It is not clear whether one or both of these metabolites is responsible for this effect. The present study therefore investigates the possible manner in which 6-hydroxymelatonin protects against oxidative stress induced by cyanide in rat brain homogenates. We examined the ability of 6-hydroxymelatonin to scavenge KCN-induced superoxide anion generation as well as lipid peroxidation. In addition, we also examined the effect of this indole on lactate dehydrogenase activity (LDH) as well as mitochondrial electron transport using dichlorophenol–indophenol as an electron acceptor. The results of this study show that 6-hydroxymelatonin significantly reduces KCN-induced superoxide anion generation, which is accompanied by a commensurate reduction in lipid peroxidation. Partial reversal of the KCN-induced reduction in mitochondrial electron transport is accompanied by a similar reversal of mitochondrial LDH activity blunted by KCN. It can thus be proposed that 6-hydroxymelatonin is potentially neuroprotective against KCN-induced neurotoxicity.
- Full Text:
- Date Issued: 2003
MMORPG: Towards a Sustainable Livelihood Model for Africa and Beyond
- Mostert, Andre, Kaschula, Russell H
- Authors: Mostert, Andre , Kaschula, Russell H
- Date: 2011
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/175212 , vital:42553 , ISBN ViNOrg 2011 , https://link.springer.com/chapter/10.1007/978-3-642-31800-9_4
- Description: The burgeoning worlds of massively multiplayer online role-playing games (MMORPG) coupled with increasing access to the internet is opening a new paradigmatic window for a number of disciplines. Many of these have been slow to take up the challenges associated with this emergent framework, due, in no small measure, to the perception that work and play are mutually exclusive. The dominance of this dichotomy contributed to the slow uptake of the potential for these virtual worlds to be harnessed in the fields of education and employment. This reticence was due in no small measure to the technophobia that tends to characterise the adoption of new technologies within fields that have customarily eschewed an embrace.
- Full Text:
- Date Issued: 2011
- Authors: Mostert, Andre , Kaschula, Russell H
- Date: 2011
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/175212 , vital:42553 , ISBN ViNOrg 2011 , https://link.springer.com/chapter/10.1007/978-3-642-31800-9_4
- Description: The burgeoning worlds of massively multiplayer online role-playing games (MMORPG) coupled with increasing access to the internet is opening a new paradigmatic window for a number of disciplines. Many of these have been slow to take up the challenges associated with this emergent framework, due, in no small measure, to the perception that work and play are mutually exclusive. The dominance of this dichotomy contributed to the slow uptake of the potential for these virtual worlds to be harnessed in the fields of education and employment. This reticence was due in no small measure to the technophobia that tends to characterise the adoption of new technologies within fields that have customarily eschewed an embrace.
- Full Text:
- Date Issued: 2011
A stability-indicating liquid chromatographic method for the analysis of erythromycin in stored biological fluids using amperometric detection
- Stubbs, Christopher, Haigh, John M, Kanfer, Isadore
- Authors: Stubbs, Christopher , Haigh, John M , Kanfer, Isadore
- Date: 1987
- Language: English
- Type: Article
- Identifier: vital:6430 , http://hdl.handle.net/10962/d1006592
- Description: A simple, sensitive and reliable high-performance liquid chromatographic procedure has been developed for the determination of erythromycin in human serum and urine using amperometric detection. A solid-phase extraction procedure was used followed by chromatography on a reverse-phase column. The mean recovery of erythromycin from serum and urine was 80%. This method allows both erythromycin and its principle degradation product, anhydroeythromycin, to be determined during a period of sample storage at 4 degree C and minus 15 degree C. The method is sufficiently sensitive and precise and is thus highly suited for use in both pharmacokinetic and stability studies.
- Full Text:
- Date Issued: 1987
- Authors: Stubbs, Christopher , Haigh, John M , Kanfer, Isadore
- Date: 1987
- Language: English
- Type: Article
- Identifier: vital:6430 , http://hdl.handle.net/10962/d1006592
- Description: A simple, sensitive and reliable high-performance liquid chromatographic procedure has been developed for the determination of erythromycin in human serum and urine using amperometric detection. A solid-phase extraction procedure was used followed by chromatography on a reverse-phase column. The mean recovery of erythromycin from serum and urine was 80%. This method allows both erythromycin and its principle degradation product, anhydroeythromycin, to be determined during a period of sample storage at 4 degree C and minus 15 degree C. The method is sufficiently sensitive and precise and is thus highly suited for use in both pharmacokinetic and stability studies.
- Full Text:
- Date Issued: 1987
Synthetic, characterization and cytotoxic studies of ruthenium complexes with Schiff bases encompassing biologically relevant moieties:
- Maikoo, Sanam, Dingle, Laura M K, Chakraborty, Abir, Xulu, Bheki, Edkins, Adrienne L, Booysen, Irvin N
- Authors: Maikoo, Sanam , Dingle, Laura M K , Chakraborty, Abir , Xulu, Bheki , Edkins, Adrienne L , Booysen, Irvin N
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165429 , vital:41243 , https://doi.org/10.1016/j.poly.2020.114569
- Description: This research study describes the formation and characterization of novel paramagnetic ruthenium complexes, cis-Cl, trans-P-[RuIIICl2(carboim)(PPh3)2] with bidentate chelating carbohydrazide Schiff bases (carboim = bpc for 1, ttc for 2 and tpc for 3). These metal complexes were synthesized by the equimolar coordination reactions of trans-[RuCl2(PPh3)2] with N-[1,3-benzothiazole-2-ylmethylidene]pyridine-2-carbohydrazide (Hbpc), N-((uracil-5-yl)methylene)thiophene-2-carbohydrazide (Httc) and N-[(uracil-5-yl)methylidene]pyridine-2-carbohydrazide (Htpc), respectively. Physicochemical techniques including nuclear magnetic resonance-, electron-spin resonance- and infrared spectroscopy, UV–Vis spectrophotometry, voltammetry as well as molar conductivity measurements provided definitive determinations of the respective ruthenium compounds’ structures.
- Full Text:
- Date Issued: 2020
- Authors: Maikoo, Sanam , Dingle, Laura M K , Chakraborty, Abir , Xulu, Bheki , Edkins, Adrienne L , Booysen, Irvin N
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165429 , vital:41243 , https://doi.org/10.1016/j.poly.2020.114569
- Description: This research study describes the formation and characterization of novel paramagnetic ruthenium complexes, cis-Cl, trans-P-[RuIIICl2(carboim)(PPh3)2] with bidentate chelating carbohydrazide Schiff bases (carboim = bpc for 1, ttc for 2 and tpc for 3). These metal complexes were synthesized by the equimolar coordination reactions of trans-[RuCl2(PPh3)2] with N-[1,3-benzothiazole-2-ylmethylidene]pyridine-2-carbohydrazide (Hbpc), N-((uracil-5-yl)methylene)thiophene-2-carbohydrazide (Httc) and N-[(uracil-5-yl)methylidene]pyridine-2-carbohydrazide (Htpc), respectively. Physicochemical techniques including nuclear magnetic resonance-, electron-spin resonance- and infrared spectroscopy, UV–Vis spectrophotometry, voltammetry as well as molar conductivity measurements provided definitive determinations of the respective ruthenium compounds’ structures.
- Full Text:
- Date Issued: 2020
Vice-Chancellor's graduation ceremonies and chancellor's installation address
- Authors: Badat, Saleem
- Date: 2013-04-05
- Language: English
- Type: Text
- Identifier: vital:7912 , http://hdl.handle.net/10962/d1016462
- Full Text:
- Date Issued: 2013-04-05
- Authors: Badat, Saleem
- Date: 2013-04-05
- Language: English
- Type: Text
- Identifier: vital:7912 , http://hdl.handle.net/10962/d1016462
- Full Text:
- Date Issued: 2013-04-05
Using camera traps to generate a species inventory for medium-sized and large mammals in South West Zimbabwe:
- Welch, Rebecca J, Grant, Tanith, Parker, Daniel M
- Authors: Welch, Rebecca J , Grant, Tanith , Parker, Daniel M
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150267 , vital:38955 , https://0-doi.org.wam.seals.ac.za/10.3957/056.049.0089
- Description: We investigated the presence of medium-sized and large mammals utilizing by-catch data from a camera trapping survey in the Mangwe District in South West Zimbabwe, an unprotected commercial livestock farming area which is impacted by human encroachment, poaching and trophy hunting. The camera trapping survey was carried out from 23 October to 5 December 2009, covered an area of 200 km2 and was initially intended to estimate the population density of leopards (Panthera pardus). The study area was split into two contiguous subsections, with each section sampled for a total of 20 days using 20 cameras. Camera trap photographs were identified to species level, then compared to a list of species thought to occur in the area according to available literature, as well as sightings from professional hunters and local landowners.
- Full Text:
- Date Issued: 2019
- Authors: Welch, Rebecca J , Grant, Tanith , Parker, Daniel M
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150267 , vital:38955 , https://0-doi.org.wam.seals.ac.za/10.3957/056.049.0089
- Description: We investigated the presence of medium-sized and large mammals utilizing by-catch data from a camera trapping survey in the Mangwe District in South West Zimbabwe, an unprotected commercial livestock farming area which is impacted by human encroachment, poaching and trophy hunting. The camera trapping survey was carried out from 23 October to 5 December 2009, covered an area of 200 km2 and was initially intended to estimate the population density of leopards (Panthera pardus). The study area was split into two contiguous subsections, with each section sampled for a total of 20 days using 20 cameras. Camera trap photographs were identified to species level, then compared to a list of species thought to occur in the area according to available literature, as well as sightings from professional hunters and local landowners.
- Full Text:
- Date Issued: 2019
Impact of marine inundation after a period of drought on the lakeshore vegetation of Lake St Lucia, South Africa: resilience of estuarine vegetation
- Sieben, E J J, Ellery, William F N, Dullo, B W, Grootjans, A P
- Authors: Sieben, E J J , Ellery, William F N , Dullo, B W , Grootjans, A P
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/144443 , vital:38346 , DOI: 10.2989/16085914.2015.1032208
- Description: The shore of Lake St Lucia in the vicinity of Catalina Bay, in the southern part of the lake, receives freshwater input as surface and groundwater seepage from the adjacent elevated coastal plain. Vegetation, water quality and landform were recorded on the lakeshore and on the dry lakebed near one of these seepage zones. This was done along a gradient perpendicular to the lakeshore and along the lakeshore away from the fluvial source of freshwater input. A number of plant communities were found along a gradient of water salinity from the shoreline (fresh water) towards the centre of the lake, and also away from the fluvial input of water (increasingly saline). Species richness decreased with increasing salinity. The first study was conducted in 2006 after a prolonged drought associated with low lake levels and closure of the mouth, and repeated again in 2010 three years after breaching of the estuarine mouth by a tropical cyclone at sea, which caused inundation of the partly dry lakebed with sea water. The vegetation of the lakeshore after these major disturbances was remarkably similar in the two time periods, suggesting rapid recovery near freshwater seepage zones, following an influx of sea water.
- Full Text:
- Date Issued: 2015
- Authors: Sieben, E J J , Ellery, William F N , Dullo, B W , Grootjans, A P
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/144443 , vital:38346 , DOI: 10.2989/16085914.2015.1032208
- Description: The shore of Lake St Lucia in the vicinity of Catalina Bay, in the southern part of the lake, receives freshwater input as surface and groundwater seepage from the adjacent elevated coastal plain. Vegetation, water quality and landform were recorded on the lakeshore and on the dry lakebed near one of these seepage zones. This was done along a gradient perpendicular to the lakeshore and along the lakeshore away from the fluvial source of freshwater input. A number of plant communities were found along a gradient of water salinity from the shoreline (fresh water) towards the centre of the lake, and also away from the fluvial input of water (increasingly saline). Species richness decreased with increasing salinity. The first study was conducted in 2006 after a prolonged drought associated with low lake levels and closure of the mouth, and repeated again in 2010 three years after breaching of the estuarine mouth by a tropical cyclone at sea, which caused inundation of the partly dry lakebed with sea water. The vegetation of the lakeshore after these major disturbances was remarkably similar in the two time periods, suggesting rapid recovery near freshwater seepage zones, following an influx of sea water.
- Full Text:
- Date Issued: 2015