The willingness to pay for dusky kob (Argyrosomus japonicus) restocking: using recreational linefishing licence fees to fund stock enhancement in South Africa
- Palmer, Ryan M, Snowball, Jeanette D
- Authors: Palmer, Ryan M , Snowball, Jeanette D
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/71322 , vital:29833 , https://doi.org/10.1093/icesjms/fsp075
- Description: The economic feasibility of stock enhancement of Argyrosomus japonicus in South Africa was investigated using a willingness-to-pay (WTP) survey. The pilot study provides a unique example of the use of the contingent valuation method as a valuation tool for a proposed stock enhancement programme. An increase in the cost of a recreational fishing permit is used as a potential vehicle of payment. The median value of the maximum that fishers were willing to pay for a recreational fishing permit was R155 (South African Rand) for frequent fishers and R100 for non-frequent fishers. Analysis showed that a fee of more than R100 excluded up to 50% of anglers from the fishery, but that a fee of R100 excluded only 28% of recreational anglers and would generate an additional R12 million annually from the sale of recreational fishing permits. The estimated costs of set-up and running of a stock enhancement programme are substantially lower than this, suggesting that stock enhancement may be an economically feasible management option that deserves more investigation. The WTP method itself produces robust results and is likely to be an effective tool in the management of the marine environment.
- Full Text:
- Date Issued: 2009
- Authors: Palmer, Ryan M , Snowball, Jeanette D
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/71322 , vital:29833 , https://doi.org/10.1093/icesjms/fsp075
- Description: The economic feasibility of stock enhancement of Argyrosomus japonicus in South Africa was investigated using a willingness-to-pay (WTP) survey. The pilot study provides a unique example of the use of the contingent valuation method as a valuation tool for a proposed stock enhancement programme. An increase in the cost of a recreational fishing permit is used as a potential vehicle of payment. The median value of the maximum that fishers were willing to pay for a recreational fishing permit was R155 (South African Rand) for frequent fishers and R100 for non-frequent fishers. Analysis showed that a fee of more than R100 excluded up to 50% of anglers from the fishery, but that a fee of R100 excluded only 28% of recreational anglers and would generate an additional R12 million annually from the sale of recreational fishing permits. The estimated costs of set-up and running of a stock enhancement programme are substantially lower than this, suggesting that stock enhancement may be an economically feasible management option that deserves more investigation. The WTP method itself produces robust results and is likely to be an effective tool in the management of the marine environment.
- Full Text:
- Date Issued: 2009
An Investigation into the Performance of General Sorting on Graphics Processing Units
- Pilkington, Nick, Irwin, Barry V W
- Authors: Pilkington, Nick , Irwin, Barry V W
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429881 , vital:72648 , https://doi.org/10.1007/978-1-4020-8741-7_65
- Description: Sorting is a fundamental operation in computing and there is a constant need to push the boundaries of performance with different sorting algo-rithms. With the advent of the programmable graphics pipeline, the par-allel nature of graphics processing units has been exposed allowing programmers to take advantage of it. By transforming the way that data is represented and operated on parallel sorting algorithms can be im-plemented on graphics processing units where previously only graphics processing could be performed. This paradigm of programming exhibits potentially large speedups for algorithms.
- Full Text:
- Date Issued: 2008
- Authors: Pilkington, Nick , Irwin, Barry V W
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429881 , vital:72648 , https://doi.org/10.1007/978-1-4020-8741-7_65
- Description: Sorting is a fundamental operation in computing and there is a constant need to push the boundaries of performance with different sorting algo-rithms. With the advent of the programmable graphics pipeline, the par-allel nature of graphics processing units has been exposed allowing programmers to take advantage of it. By transforming the way that data is represented and operated on parallel sorting algorithms can be im-plemented on graphics processing units where previously only graphics processing could be performed. This paradigm of programming exhibits potentially large speedups for algorithms.
- Full Text:
- Date Issued: 2008
Flock inspired area coverage using wireless boid-like sensor agents
- Chibaya, Colin, Bangay, Shaun D
- Authors: Chibaya, Colin , Bangay, Shaun D
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/433440 , vital:72970 , 10.1109/UKSIM.2008.102
- Description: Simulated flocking is achievable using three boid rules [13]. We propose an area coverage model inspired by Reynolds’ flocking algorithm, investigating strategies for achieving quality coverage using flocking rules. Our agents are identical and autonomous, using only local sensory information for indirect communication. Upon deployment, agents are in the default separation mode. The cohesion rule would then guarantee that agents remain within the swarm, covering spaces with explored neighbour spaces. Four experiments are conducted to evaluate our model in terms of coverage quality achieved. We firstly investigate agents’ separation speed before the speed with which isolated agents re-organizes is investigated. The third experiment compares coverage quality achieved using our model with coverage quality achieved using random guessing. Finally, we investigate fault tolerance in the event of agents’ failures. Our model exhibits good separation and cohesion speed, achieving high quality coverage. Additionally, the model is fault tolerant and adaptive to agents’ failures.
- Full Text:
- Date Issued: 2008
- Authors: Chibaya, Colin , Bangay, Shaun D
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/433440 , vital:72970 , 10.1109/UKSIM.2008.102
- Description: Simulated flocking is achievable using three boid rules [13]. We propose an area coverage model inspired by Reynolds’ flocking algorithm, investigating strategies for achieving quality coverage using flocking rules. Our agents are identical and autonomous, using only local sensory information for indirect communication. Upon deployment, agents are in the default separation mode. The cohesion rule would then guarantee that agents remain within the swarm, covering spaces with explored neighbour spaces. Four experiments are conducted to evaluate our model in terms of coverage quality achieved. We firstly investigate agents’ separation speed before the speed with which isolated agents re-organizes is investigated. The third experiment compares coverage quality achieved using our model with coverage quality achieved using random guessing. Finally, we investigate fault tolerance in the event of agents’ failures. Our model exhibits good separation and cohesion speed, achieving high quality coverage. Additionally, the model is fault tolerant and adaptive to agents’ failures.
- Full Text:
- Date Issued: 2008
AfrOBIS: a marine biogeographic information system for sub-Saharan Africa
- Grundlingh, M L, St Ange, U B, Bolton, John J
- Authors: Grundlingh, M L , St Ange, U B , Bolton, John J
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:7137 , http://hdl.handle.net/10962/d1011813
- Description: AfrOBIS is one of 11 global nodes of the Ocean Biogeographic Information System (OBIS), a freely accessible network of databases collating marine data in support of the Census of Marine Life.Versatile graphic products, provided by OBIS, can be used to display the data. To date, AfrOBIS has loaded about 3.2 million records of more than 23 000 species located mainly in the seas around southern Africa. This forms part of the 13.2 million records of more than 80 000 species currently stored in OBIS. Scouting for South African data has been successful, whereas locating records in other African countries has been much less so.
- Full Text:
- Date Issued: 2007
- Authors: Grundlingh, M L , St Ange, U B , Bolton, John J
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:7137 , http://hdl.handle.net/10962/d1011813
- Description: AfrOBIS is one of 11 global nodes of the Ocean Biogeographic Information System (OBIS), a freely accessible network of databases collating marine data in support of the Census of Marine Life.Versatile graphic products, provided by OBIS, can be used to display the data. To date, AfrOBIS has loaded about 3.2 million records of more than 23 000 species located mainly in the seas around southern Africa. This forms part of the 13.2 million records of more than 80 000 species currently stored in OBIS. Scouting for South African data has been successful, whereas locating records in other African countries has been much less so.
- Full Text:
- Date Issued: 2007
Bee-hawking by the wasp, Vespa velutina, on the honeybees Apis cerana and A. mellifera
- Tan, K, Radloff, Sarah E, Li, J J, Hepburn, H Randall, Yang, Ming-Xian, Zhang, L J, Neumann, Peter
- Authors: Tan, K , Radloff, Sarah E , Li, J J , Hepburn, H Randall , Yang, Ming-Xian , Zhang, L J , Neumann, Peter
- Date: 2007
- Language: English
- Type: text , Article
- Identifier: vital:6941 , http://hdl.handle.net/10962/d1011965
- Description: The vespine wasps, Vespa velutina, specialise in hawking honeybee foragers returning to their nests. We studied their behaviour in China using native Apis cerana and introduced A. mellifera colonies. When the wasps are hawking, A. cerana recruits threefold more guard bees to stave off predation than A. mellifera. The former also utilises wing shimmering as a visual pattern disruption mechanism, which is not shown by A. mellifera. A. cerana foragers halve the time of normal flight needed to dart into the nest entrance, while A. mellifera actually slows down in sashaying flight manoeuvres. V. velutina preferentially hawks A. mellifera foragers when both A. mellifera and A. cerana occur in the same apiary. The pace of wasp-hawking was highest in mid-summer but the frequency of hawking wasps was three times higher at A. mellifera colonies than at the A. cerana colonies. The wasps were taking A. mellifera foragers at a frequency eightfold greater than A. cerana foragers. The final hawking success rates of the wasps were about three times higher for A. mellifera foragers than for A. cerana. The relative success of native A. cerana over European A. mellifera in thwarting predation by the wasp V. velutina is interpreted as the result of co-evolution between the Asian wasp and honeybee, respectively.
- Full Text:
- Date Issued: 2007
- Authors: Tan, K , Radloff, Sarah E , Li, J J , Hepburn, H Randall , Yang, Ming-Xian , Zhang, L J , Neumann, Peter
- Date: 2007
- Language: English
- Type: text , Article
- Identifier: vital:6941 , http://hdl.handle.net/10962/d1011965
- Description: The vespine wasps, Vespa velutina, specialise in hawking honeybee foragers returning to their nests. We studied their behaviour in China using native Apis cerana and introduced A. mellifera colonies. When the wasps are hawking, A. cerana recruits threefold more guard bees to stave off predation than A. mellifera. The former also utilises wing shimmering as a visual pattern disruption mechanism, which is not shown by A. mellifera. A. cerana foragers halve the time of normal flight needed to dart into the nest entrance, while A. mellifera actually slows down in sashaying flight manoeuvres. V. velutina preferentially hawks A. mellifera foragers when both A. mellifera and A. cerana occur in the same apiary. The pace of wasp-hawking was highest in mid-summer but the frequency of hawking wasps was three times higher at A. mellifera colonies than at the A. cerana colonies. The wasps were taking A. mellifera foragers at a frequency eightfold greater than A. cerana foragers. The final hawking success rates of the wasps were about three times higher for A. mellifera foragers than for A. cerana. The relative success of native A. cerana over European A. mellifera in thwarting predation by the wasp V. velutina is interpreted as the result of co-evolution between the Asian wasp and honeybee, respectively.
- Full Text:
- Date Issued: 2007
Bridging the gap for Next Generation Services: Presence Services on Legacy Devices
- Moyo, Thamsanqa, Thinyane, Mamello, Wright, Madeleine, Irwin, Barry V W, Clayton, Peter G, Terzoli, Alfredo
- Authors: Moyo, Thamsanqa , Thinyane, Mamello , Wright, Madeleine , Irwin, Barry V W , Clayton, Peter G , Terzoli, Alfredo
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428177 , vital:72491 , https://d1wqtxts1xzle7.cloudfront.net/49665432/Paper_2063_20-_20Moyo-libre.pdf?1476717366=andresponse-content-disposi-tion=inline%3B+filename%3DBridging_the_gap_for_Next_Generation_Ser.pdfandEx-pires=1714737455andSignature=RRbr9pzIYSYX8v7FG6FzV4tu3dFXm9qmmqq5WirOhuYdt--mjOfcDHQNLPYZHCmtgYZWdVk6bVFxfGOVJxgXrvkTe2QN2AZV3XfFTZ3mi1s3A5gw2jIXOVHrYUnaf~POgdijdY85mqWhco3vL6Qk3sOZgYjIlTF5ZGAKg1S54W978Nom01cT2~oqRA0Et6mTNmydWfF5MhFxQIq~LNmYqEqmEESKkkWQFwg6xJJUu0uGffbaZXXBA6oDI2cpfkz1FleKyKaRDRJvdfnuTHPoJJ4TzfO6DDVCWKvJ45jaxIzaGmK-03Ai29I-DPyy-c557kZh~kF3rmDg3zrXVNaL8A__andKey-Pair-Id=APKAJLOHF5GGSLRBV4ZA
- Description: Next generation services are provided by applications that leverage packet-based domains. A challenge faced by such services is the support for multiple devices, including legacy devices. Our paper examines a strategy for the pro-vision of next generation services on legacy cellular network devices. We ad-vocate that the provision of next generation services via applications on the SIM card allows for the deployment of such services on legacy devices. We demonstrate this assertion through a proof of concept application, SIMPre, that resides on a SIM card. SIMPre implements a presence service by leveraging Java Card, the SIM Application Toolkit and the OMA IMPS standard. We show that it is possible to provide a next generation service on the SIM card such that it ubiquitously integrates with the functionality of a legacy device. We con-clude through this demonstration that the SIM card is a viable option for provid-ing backward compatibility to legacy devices in the implementation of next generation services.
- Full Text:
- Date Issued: 2007
- Authors: Moyo, Thamsanqa , Thinyane, Mamello , Wright, Madeleine , Irwin, Barry V W , Clayton, Peter G , Terzoli, Alfredo
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428177 , vital:72491 , https://d1wqtxts1xzle7.cloudfront.net/49665432/Paper_2063_20-_20Moyo-libre.pdf?1476717366=andresponse-content-disposi-tion=inline%3B+filename%3DBridging_the_gap_for_Next_Generation_Ser.pdfandEx-pires=1714737455andSignature=RRbr9pzIYSYX8v7FG6FzV4tu3dFXm9qmmqq5WirOhuYdt--mjOfcDHQNLPYZHCmtgYZWdVk6bVFxfGOVJxgXrvkTe2QN2AZV3XfFTZ3mi1s3A5gw2jIXOVHrYUnaf~POgdijdY85mqWhco3vL6Qk3sOZgYjIlTF5ZGAKg1S54W978Nom01cT2~oqRA0Et6mTNmydWfF5MhFxQIq~LNmYqEqmEESKkkWQFwg6xJJUu0uGffbaZXXBA6oDI2cpfkz1FleKyKaRDRJvdfnuTHPoJJ4TzfO6DDVCWKvJ45jaxIzaGmK-03Ai29I-DPyy-c557kZh~kF3rmDg3zrXVNaL8A__andKey-Pair-Id=APKAJLOHF5GGSLRBV4ZA
- Description: Next generation services are provided by applications that leverage packet-based domains. A challenge faced by such services is the support for multiple devices, including legacy devices. Our paper examines a strategy for the pro-vision of next generation services on legacy cellular network devices. We ad-vocate that the provision of next generation services via applications on the SIM card allows for the deployment of such services on legacy devices. We demonstrate this assertion through a proof of concept application, SIMPre, that resides on a SIM card. SIMPre implements a presence service by leveraging Java Card, the SIM Application Toolkit and the OMA IMPS standard. We show that it is possible to provide a next generation service on the SIM card such that it ubiquitously integrates with the functionality of a legacy device. We con-clude through this demonstration that the SIM card is a viable option for provid-ing backward compatibility to legacy devices in the implementation of next generation services.
- Full Text:
- Date Issued: 2007
Bridging the gap for Next Generation Services: Presence Services on Legacy Devices
- Moyo, Thamsanqa, Thinyane, Mamello, Wright, Madeleine, Irwin, Barry V W, Clayton, Peter G, Terzoli, Alfredo
- Authors: Moyo, Thamsanqa , Thinyane, Mamello , Wright, Madeleine , Irwin, Barry V W , Clayton, Peter G , Terzoli, Alfredo
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428176 , vital:72492 , https://d1wqtxts1xzle7.cloudfront.net/49665432/Paper_2063_20-_20Moyo-libre.pdf?1476717366=andresponse-content-disposi-tion=inline%3B+filename%3DBridging_the_gap_for_Next_Generation_Ser.pdfandEx-pires=1714737455andSignature=RRbr9pzIYSYX8v7FG6FzV4tu3dFXm9qmmqq5WirOhuYdt--mjOfcDHQNLPYZHCmtgYZWdVk6bVFxfGOVJxgXrvkTe2QN2AZV3XfFTZ3mi1s3A5gw2jIXOVHrYUnaf~POgdijdY85mqWhco3vL6Qk3sOZgYjIlTF5ZGAKg1S54W978Nom01cT2~oqRA0Et6mTNmydWfF5MhFxQIq~LNmYqEqmEESKkkWQFwg6xJJUu0uGffbaZXXBA6oDI2cpfkz1FleKyKaRDRJvdfnuTHPoJJ4TzfO6DDVCWKvJ45jaxIzaGmK-03Ai29I-DPyy-c557kZh~kF3rmDg3zrXVNaL8A__andKey-Pair-Id=APKAJLOHF5GGSLRBV4ZA
- Description: Next generation services are provided by applications that leverage packet-based domains. A challenge faced by such services is the support for multiple devices, including legacy devices. Our paper examines a strategy for the pro-vision of next generation services on legacy cellular network devices. We ad-vocate that the provision of next generation services via applications on the SIM card allows for the deployment of such services on legacy devices. We demonstrate this assertion through a proof of concept application, SIMPre, that resides on a SIM card. SIMPre implements a presence service by leveraging Java Card, the SIM Application Toolkit and the OMA IMPS standard. We show that it is possible to provide a next generation service on the SIM card such that it ubiquitously integrates with the functionality of a legacy device. We con-clude through this demonstration that the SIM card is a viable option for provid-ing backward compatibility to legacy devices in the implementation of next generation services.
- Full Text:
- Date Issued: 2007
- Authors: Moyo, Thamsanqa , Thinyane, Mamello , Wright, Madeleine , Irwin, Barry V W , Clayton, Peter G , Terzoli, Alfredo
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428176 , vital:72492 , https://d1wqtxts1xzle7.cloudfront.net/49665432/Paper_2063_20-_20Moyo-libre.pdf?1476717366=andresponse-content-disposi-tion=inline%3B+filename%3DBridging_the_gap_for_Next_Generation_Ser.pdfandEx-pires=1714737455andSignature=RRbr9pzIYSYX8v7FG6FzV4tu3dFXm9qmmqq5WirOhuYdt--mjOfcDHQNLPYZHCmtgYZWdVk6bVFxfGOVJxgXrvkTe2QN2AZV3XfFTZ3mi1s3A5gw2jIXOVHrYUnaf~POgdijdY85mqWhco3vL6Qk3sOZgYjIlTF5ZGAKg1S54W978Nom01cT2~oqRA0Et6mTNmydWfF5MhFxQIq~LNmYqEqmEESKkkWQFwg6xJJUu0uGffbaZXXBA6oDI2cpfkz1FleKyKaRDRJvdfnuTHPoJJ4TzfO6DDVCWKvJ45jaxIzaGmK-03Ai29I-DPyy-c557kZh~kF3rmDg3zrXVNaL8A__andKey-Pair-Id=APKAJLOHF5GGSLRBV4ZA
- Description: Next generation services are provided by applications that leverage packet-based domains. A challenge faced by such services is the support for multiple devices, including legacy devices. Our paper examines a strategy for the pro-vision of next generation services on legacy cellular network devices. We ad-vocate that the provision of next generation services via applications on the SIM card allows for the deployment of such services on legacy devices. We demonstrate this assertion through a proof of concept application, SIMPre, that resides on a SIM card. SIMPre implements a presence service by leveraging Java Card, the SIM Application Toolkit and the OMA IMPS standard. We show that it is possible to provide a next generation service on the SIM card such that it ubiquitously integrates with the functionality of a legacy device. We con-clude through this demonstration that the SIM card is a viable option for provid-ing backward compatibility to legacy devices in the implementation of next generation services.
- Full Text:
- Date Issued: 2007
Climate change, genetics or human choice: why were the shells of mankind’s earliest ornament larger in the Pleistocene than in the Holocene?
- Teske, Peter R, Papadopoulos, Isabelle, McQuaid, Christopher D, Newman, Brent K, Barker, Nigel P
- Authors: Teske, Peter R , Papadopoulos, Isabelle , McQuaid, Christopher D , Newman, Brent K , Barker, Nigel P
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6952 , http://hdl.handle.net/10962/d1011984
- Description: The southern African tick shell, Nassarius kraussianus (Dunker, 1846), has been identified as being the earliest known ornamental object used by human beings. Shell beads dated from ~75,000 years ago (Pleistocene era) were found in a cave located on South Africa's south coast. Beads made from N. kraussianus shells have also been found in deposits in this region dating from the beginning of the Holocene era (<10,000 years ago). These younger shells were significantly smaller, a phenomenon that has been attributed to a change in human preference. We investigated two alternative hypotheses explaining the difference in shell size: a) N. kraussianus comprises at least two genetic lineages that differ in size; b) the difference in shell size is due to phenotypic plasticity and is a function of environmental conditions. To test these hypotheses, we first reconstructed the species' phylogeographic history, and second, we measured the shell sizes of extant individuals throughout South Africa. Although two genetic lineages were identified, the sharing of haplotypes between these suggests that there is no genetic basis for the size differences. Extant individuals from the cool temperate west coast had significantly larger shells than populations in the remainder of the country, suggesting that N. kraussianus grows to a larger size in colder water. The decrease in fossil shell size from Pleistocene to Holocene was likely due to increased temperatures as a result of climate change at the beginning of the present interglacial period. We hypothesise that the sizes of N. kraussianus fossil shells can therefore serve as indicators of the climatic conditions that were prevalent in a particular region at the time when they were deposited. Moreover, N. kraussianus could serve as a biomonitor to study the impacts of future climate change on coastal biota in southern Africa.
- Full Text:
- Date Issued: 2007
- Authors: Teske, Peter R , Papadopoulos, Isabelle , McQuaid, Christopher D , Newman, Brent K , Barker, Nigel P
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6952 , http://hdl.handle.net/10962/d1011984
- Description: The southern African tick shell, Nassarius kraussianus (Dunker, 1846), has been identified as being the earliest known ornamental object used by human beings. Shell beads dated from ~75,000 years ago (Pleistocene era) were found in a cave located on South Africa's south coast. Beads made from N. kraussianus shells have also been found in deposits in this region dating from the beginning of the Holocene era (<10,000 years ago). These younger shells were significantly smaller, a phenomenon that has been attributed to a change in human preference. We investigated two alternative hypotheses explaining the difference in shell size: a) N. kraussianus comprises at least two genetic lineages that differ in size; b) the difference in shell size is due to phenotypic plasticity and is a function of environmental conditions. To test these hypotheses, we first reconstructed the species' phylogeographic history, and second, we measured the shell sizes of extant individuals throughout South Africa. Although two genetic lineages were identified, the sharing of haplotypes between these suggests that there is no genetic basis for the size differences. Extant individuals from the cool temperate west coast had significantly larger shells than populations in the remainder of the country, suggesting that N. kraussianus grows to a larger size in colder water. The decrease in fossil shell size from Pleistocene to Holocene was likely due to increased temperatures as a result of climate change at the beginning of the present interglacial period. We hypothesise that the sizes of N. kraussianus fossil shells can therefore serve as indicators of the climatic conditions that were prevalent in a particular region at the time when they were deposited. Moreover, N. kraussianus could serve as a biomonitor to study the impacts of future climate change on coastal biota in southern Africa.
- Full Text:
- Date Issued: 2007
Development of Cactoblastis cactorum (Berg)(Lepidoptera: pyralidae) on six north American Opuntia species
- Mafokoane, L D, Zimmermann, Helmuth G, Hill, Martin P
- Authors: Mafokoane, L D , Zimmermann, Helmuth G , Hill, Martin P
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/451346 , vital:75042 , https://hdl.handle.net/10520/EJC32740
- Description: Cactoblastis cactorum (Berg) (Lepidoptera : Pyralidae) has been used as a biological control agent of several Opuntia species around the world and is widely assumed to be a generalist on host plants within the genus Opuntia. The recent arrival and spread of C. cactorum on the North American mainland has raised concerns for the native species of Opuntia that are being utilized as hosts by the moth. To confirm that C. cactorum is a threat to a wide range of Opuntia species in North America, the host range of the moths was scrutinized in South Africa, where larval development could be monitored on several Opuntia species under natural conditions. Development was monitored on Opuntia ficus-indica L. Miller, O. engelmannii Salm-Dyke, O. fulgida Englm, O. imbricata (Haworth) de Candolle, O. stricta Haworth and O. leucotrichta DC. Larval survival, egg to pupation, was highest on O. ficus-indica (79.2%) followed by O. engelmannii (57.5 %), O. stricta (55.0 %), O. leucotrichta (29.2 %), O. fulgida (24.2 %) and O. imbricata (16.7 %). Male and female pupal mass was highest, and duration of development shortest on O. ficus-indica. In adult multi-choice oviposition trials, females laid significantly more egg sticks on O. ficus-indica than on the other species. Although O. ficusindica is the preferred host for C. cactorum in South Africa, the moth is nevertheless able to utilize several other species of Opuntia as hosts.
- Full Text:
- Date Issued: 2007
- Authors: Mafokoane, L D , Zimmermann, Helmuth G , Hill, Martin P
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/451346 , vital:75042 , https://hdl.handle.net/10520/EJC32740
- Description: Cactoblastis cactorum (Berg) (Lepidoptera : Pyralidae) has been used as a biological control agent of several Opuntia species around the world and is widely assumed to be a generalist on host plants within the genus Opuntia. The recent arrival and spread of C. cactorum on the North American mainland has raised concerns for the native species of Opuntia that are being utilized as hosts by the moth. To confirm that C. cactorum is a threat to a wide range of Opuntia species in North America, the host range of the moths was scrutinized in South Africa, where larval development could be monitored on several Opuntia species under natural conditions. Development was monitored on Opuntia ficus-indica L. Miller, O. engelmannii Salm-Dyke, O. fulgida Englm, O. imbricata (Haworth) de Candolle, O. stricta Haworth and O. leucotrichta DC. Larval survival, egg to pupation, was highest on O. ficus-indica (79.2%) followed by O. engelmannii (57.5 %), O. stricta (55.0 %), O. leucotrichta (29.2 %), O. fulgida (24.2 %) and O. imbricata (16.7 %). Male and female pupal mass was highest, and duration of development shortest on O. ficus-indica. In adult multi-choice oviposition trials, females laid significantly more egg sticks on O. ficus-indica than on the other species. Although O. ficusindica is the preferred host for C. cactorum in South Africa, the moth is nevertheless able to utilize several other species of Opuntia as hosts.
- Full Text:
- Date Issued: 2007
Evaluating compression as an enabler for centralised monitoring in a Next Generation Network
- Otten, Fred, Irwin, Barry V W, Slay, Hannah
- Authors: Otten, Fred , Irwin, Barry V W , Slay, Hannah
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428226 , vital:72495 , https://citeseerx.ist.psu.edu/document?repid=rep1andtype=pdfanddoi=f9ed69db7da44c168082934cd4ea5a413b2bf7f5
- Description: With the emergence of Next Generation Networks and a large number of next generation services, the volume and diversity of information is on the rise. These networks are often large, distributed and consist of het-erogeneous devices. In order to provide effective centralised monitoring and control we need to be able to assemble the relevant data at a cen-tral point. This becomes difficult because of the large quantity of data. We also would like to achieve this using the least amount of bandwidth, and minimise the latency. This paper investigates using compression to enable centralised monitoring and control. It presents the results of ex-periments showing that compression is an effective method of data re-duction, resulting in up to 93.3 percent reduction in bandwidth usage for point-to-point transmission. This paper also describes an architecture that incorporates compression and provides centralised monitoring and control.
- Full Text:
- Date Issued: 2007
- Authors: Otten, Fred , Irwin, Barry V W , Slay, Hannah
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428226 , vital:72495 , https://citeseerx.ist.psu.edu/document?repid=rep1andtype=pdfanddoi=f9ed69db7da44c168082934cd4ea5a413b2bf7f5
- Description: With the emergence of Next Generation Networks and a large number of next generation services, the volume and diversity of information is on the rise. These networks are often large, distributed and consist of het-erogeneous devices. In order to provide effective centralised monitoring and control we need to be able to assemble the relevant data at a cen-tral point. This becomes difficult because of the large quantity of data. We also would like to achieve this using the least amount of bandwidth, and minimise the latency. This paper investigates using compression to enable centralised monitoring and control. It presents the results of ex-periments showing that compression is an effective method of data re-duction, resulting in up to 93.3 percent reduction in bandwidth usage for point-to-point transmission. This paper also describes an architecture that incorporates compression and provides centralised monitoring and control.
- Full Text:
- Date Issued: 2007
The effects of buffer molarity, agitation rate and mesh size on verapamil release from modified release mini-tablets using USP Apparatus 3
- Khamanga, Sandile M, Walker, Roderick B
- Authors: Khamanga, Sandile M , Walker, Roderick B
- Date: 2007
- Language: English
- Type: text , Article
- Identifier: vital:6386 , http://hdl.handle.net/10962/d1006307
- Description: The effects of agitation rate, buffer molarity,and mesh size on the dissolution rate of verapamil hydrochloride from sustained release matrix tablets were studied using USP Apparatus 3. Eudragit® and Carbopol® were used as rate-retarding polymers in tablets prepared by wet granulation.The study was conducted to determine whether the drugs exhibit similar release characteristics when tested under the same dissolution conditions. It was found that the dissolution rate of verapamil hydrochloride was affected by the variables assessed in these studies.
- Full Text:
- Date Issued: 2007
- Authors: Khamanga, Sandile M , Walker, Roderick B
- Date: 2007
- Language: English
- Type: text , Article
- Identifier: vital:6386 , http://hdl.handle.net/10962/d1006307
- Description: The effects of agitation rate, buffer molarity,and mesh size on the dissolution rate of verapamil hydrochloride from sustained release matrix tablets were studied using USP Apparatus 3. Eudragit® and Carbopol® were used as rate-retarding polymers in tablets prepared by wet granulation.The study was conducted to determine whether the drugs exhibit similar release characteristics when tested under the same dissolution conditions. It was found that the dissolution rate of verapamil hydrochloride was affected by the variables assessed in these studies.
- Full Text:
- Date Issued: 2007
Towards continental transformation: understanding sustainable peace agreements in Africa
- Authors: Bischoff, Paul, 1954-
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/161409 , vital:40624 , https://0-hdl.handle.net.wam.seals.ac.za/10520/EJC15983
- Description: There are social and political questions to be asked about the new continent-wide institutions in and around what is still a young African Union (AU). These include questions such as whether the AU and its institutions can be built in ways that will allow this body to transform Africa's international relations, and how this is to be done. What are the norms and values that will inform this change and the African renewal promoted by the AU? Is the multilateral architecture of the AU able to encourage democracy and people-centredness, for instance? Will it, in the end, be able to deliver on the hoped-for "pan-African transnational democratic revolution"?.
- Full Text:
- Date Issued: 2007
- Authors: Bischoff, Paul, 1954-
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/161409 , vital:40624 , https://0-hdl.handle.net.wam.seals.ac.za/10520/EJC15983
- Description: There are social and political questions to be asked about the new continent-wide institutions in and around what is still a young African Union (AU). These include questions such as whether the AU and its institutions can be built in ways that will allow this body to transform Africa's international relations, and how this is to be done. What are the norms and values that will inform this change and the African renewal promoted by the AU? Is the multilateral architecture of the AU able to encourage democracy and people-centredness, for instance? Will it, in the end, be able to deliver on the hoped-for "pan-African transnational democratic revolution"?.
- Full Text:
- Date Issued: 2007
Wi-Fi as a last mile access technology and The Tragedy of the Commons
- Brandt, Ingrid, Terzoli, Alfredo, Hodgkinson-Williams, Cheryl
- Authors: Brandt, Ingrid , Terzoli, Alfredo , Hodgkinson-Williams, Cheryl
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/431106 , vital:72744 , https://doi.org/10.1007/978-1-4020-6266-7_33
- Description: With an alarmingly low teledensity in South Africa, just 12%, and not much hope of further wired infrastructure at the local loop level, as the costs incurred are high compared to potential revenue, wireless con-nectivity could be a great asset and service in South Africa. However, the use of unlicensed spectrum in building wireless networks can be comparable to “The Tragedy of the Commons”, the result of selfish be-haviour towards common and limited resources. This paper evaluates the use of 802.11 wireless technologies in building a broadband wire-less network and the effects of high amounts of interference on such a network. The paper concludes that for urban areas 802.11 technologies using unlicensed spectrum is not advisable, unless used in point-to-point links, while its use in rapid rural development (where there is less interference) is very promising.
- Full Text:
- Date Issued: 2007
- Authors: Brandt, Ingrid , Terzoli, Alfredo , Hodgkinson-Williams, Cheryl
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/431106 , vital:72744 , https://doi.org/10.1007/978-1-4020-6266-7_33
- Description: With an alarmingly low teledensity in South Africa, just 12%, and not much hope of further wired infrastructure at the local loop level, as the costs incurred are high compared to potential revenue, wireless con-nectivity could be a great asset and service in South Africa. However, the use of unlicensed spectrum in building wireless networks can be comparable to “The Tragedy of the Commons”, the result of selfish be-haviour towards common and limited resources. This paper evaluates the use of 802.11 wireless technologies in building a broadband wire-less network and the effects of high amounts of interference on such a network. The paper concludes that for urban areas 802.11 technologies using unlicensed spectrum is not advisable, unless used in point-to-point links, while its use in rapid rural development (where there is less interference) is very promising.
- Full Text:
- Date Issued: 2007
Creating a low cost VoiceXML Gateway to replace IVR systems for rapid deployment of voice applications
- King, Adam, Terzoli, Alfredo, Clayton, Peter, G
- Authors: King, Adam , Terzoli, Alfredo , Clayton, Peter, G
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427576 , vital:72448 , https://citeseerx.ist.psu.edu/document?repid=rep1andtype=pdfanddoi=af502fadc7349b9153c37f252bafbe07e86cbfd8
- Description: VoiceXML gateway which can be used to replace traditional Interactive Voice Re-sponse (IVR) platforms. The gateway is created by integrating a VoiceXML inter-preter, OpenVXI and a PBX, Asterisk, producing a Linux based, open source, sys-tem which is both a PBX and a VoiceXML browser. Reasons for choosing the components for the gateway and then the integration of these components are dis-cussed. VoiceXML applications can be used to replace IVR systems, which are then rendered by the gateway.
- Full Text:
- Date Issued: 2006
- Authors: King, Adam , Terzoli, Alfredo , Clayton, Peter, G
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427576 , vital:72448 , https://citeseerx.ist.psu.edu/document?repid=rep1andtype=pdfanddoi=af502fadc7349b9153c37f252bafbe07e86cbfd8
- Description: VoiceXML gateway which can be used to replace traditional Interactive Voice Re-sponse (IVR) platforms. The gateway is created by integrating a VoiceXML inter-preter, OpenVXI and a PBX, Asterisk, producing a Linux based, open source, sys-tem which is both a PBX and a VoiceXML browser. Reasons for choosing the components for the gateway and then the integration of these components are dis-cussed. VoiceXML applications can be used to replace IVR systems, which are then rendered by the gateway.
- Full Text:
- Date Issued: 2006
Critical media literacy: a design for the future
- Authors: Prinsloo, Jeanne
- Date: 2006
- Language: English
- Type: text , Article
- Identifier: vital:6331 , http://hdl.handle.net/10962/d1008476
- Description: [From OPENSPACE Editor Alice Kanengoni's editorial]: Professor Jeanne Prinsloo notes in her article that "In fact, it has been argued that the significance of the media in people’s lives has increased to the extent that it has been described as their primary curriculum, thereby recasting formal education as the secondary curriculum." This therefore requires an incestment in media literacy; people's ability to to understand the world around them, as represented in the media. Thus, Professor Prinsloo argues for critical media literacy, citing the role that the media played in fuelling the genocide in Rwanda, as an illustrative case in point. She states that "While we can not attribute all blame in the Rwandan scenario to the radio use, it is clear that the media mattered." She indicates that "media representations and engagements play a significant role in the way we understand the world, its people and events, and ourselves therein." As such, societies should invest in building a critical citizenry that can read and deconstruct the various ideologies that are often carries in and through the media.
- Full Text:
- Date Issued: 2006
- Authors: Prinsloo, Jeanne
- Date: 2006
- Language: English
- Type: text , Article
- Identifier: vital:6331 , http://hdl.handle.net/10962/d1008476
- Description: [From OPENSPACE Editor Alice Kanengoni's editorial]: Professor Jeanne Prinsloo notes in her article that "In fact, it has been argued that the significance of the media in people’s lives has increased to the extent that it has been described as their primary curriculum, thereby recasting formal education as the secondary curriculum." This therefore requires an incestment in media literacy; people's ability to to understand the world around them, as represented in the media. Thus, Professor Prinsloo argues for critical media literacy, citing the role that the media played in fuelling the genocide in Rwanda, as an illustrative case in point. She states that "While we can not attribute all blame in the Rwandan scenario to the radio use, it is clear that the media mattered." She indicates that "media representations and engagements play a significant role in the way we understand the world, its people and events, and ourselves therein." As such, societies should invest in building a critical citizenry that can read and deconstruct the various ideologies that are often carries in and through the media.
- Full Text:
- Date Issued: 2006
Design considerations for a reliable and secure wireless network
- Janse van Rensburg, Johanna, Irwin, Barry V W, Zhao, X G
- Authors: Janse van Rensburg, Johanna , Irwin, Barry V W , Zhao, X G
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428199 , vital:72493 , https://www.researchgate.net/profile/Barry-Ir-win/publication/327622818_Design_considerations_for_a_reliable_and_secure_wireless_network/links/5b9a114792851c4ba81819fe/Design-considerations-for-a-reliable-and-secure-wireless-network.pdf
- Description: Wireless Networks have become widely accepted in enterprise net-works and can no longer be considered an experimental technology. However users often experience performance problems due to poor designs. These problems can be attributed to the physical nature of wireless networks, the electromagnetic wave. As a wave propagates through the air it is susceptible to interference, reflection or refraction, to name a few, that changes the wave and ultimately the received signal. However the effect of these can be mitigated with the proper design of a wireless network. In this paper these design consideration will be in-troduced through discussion of visualization packages that aid in the design process. Furthermore we will take a look at the security consid-erations of wireless networks; as, surprisingly even with the ratification of 802.11 i for almost two years now; security is still considered one of the biggest challenges against implementing a wireless local area net-work.
- Full Text:
- Date Issued: 2006
- Authors: Janse van Rensburg, Johanna , Irwin, Barry V W , Zhao, X G
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428199 , vital:72493 , https://www.researchgate.net/profile/Barry-Ir-win/publication/327622818_Design_considerations_for_a_reliable_and_secure_wireless_network/links/5b9a114792851c4ba81819fe/Design-considerations-for-a-reliable-and-secure-wireless-network.pdf
- Description: Wireless Networks have become widely accepted in enterprise net-works and can no longer be considered an experimental technology. However users often experience performance problems due to poor designs. These problems can be attributed to the physical nature of wireless networks, the electromagnetic wave. As a wave propagates through the air it is susceptible to interference, reflection or refraction, to name a few, that changes the wave and ultimately the received signal. However the effect of these can be mitigated with the proper design of a wireless network. In this paper these design consideration will be in-troduced through discussion of visualization packages that aid in the design process. Furthermore we will take a look at the security consid-erations of wireless networks; as, surprisingly even with the ratification of 802.11 i for almost two years now; security is still considered one of the biggest challenges against implementing a wireless local area net-work.
- Full Text:
- Date Issued: 2006
Editorial: tracing actors, actants and relational dynamics in environmental education research
- Authors: Lotz-Sisitka, Heila
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67400 , vital:29084 , https://www.ajol.info/index.php/sajee/article/view/122719
- Description: publisher version , Introduction: This edition of the EEASA Journal provides insight into a range of relationships in the field of environmental education, and the complexities that exist around them, as reflected in the combination of papers. This Editorial picks up on the methodological ‘note’ (or is it a challenge?) provided by Godwell Nhamo in his paper in this edition of the journal. He provides a description of the possibilities that actor network theory provides for describing and explaining environmental policy processes, and recommends that environmental educators consider this methodology in their analyses. In particular, he refers environmental educators to applications of actor network theory for tracing relational dynamics between actors (i.e., environmental education practitioners) and actants which are non-human referents (e.g., the UN Decade of Education for Sustainable Development and UNESCO’s (2005) International Implementation Scheme). In response to his paper, I have chosen to ‘pick up’ on this methodological discussion in this Editorial, by considering aspects of this theoretical perspective in describing the ‘happenings’ that occur across the pages of this edition of the EEASA Journal. In doing so, I highlight (in part) the diversity of actors and actants that are influencing the field of environmental education, their subject matter and contexts, and I highlight the relational dynamics that become evident when one accepts a methodology that aims to trace such dynamics. In particular, this Editorial considers how ‘The language of actors, actants and actor/actant-networks brings to the fore the relationships and complexities that exist around them’ (Nhamo, this edition).
- Full Text:
- Date Issued: 2006
- Authors: Lotz-Sisitka, Heila
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67400 , vital:29084 , https://www.ajol.info/index.php/sajee/article/view/122719
- Description: publisher version , Introduction: This edition of the EEASA Journal provides insight into a range of relationships in the field of environmental education, and the complexities that exist around them, as reflected in the combination of papers. This Editorial picks up on the methodological ‘note’ (or is it a challenge?) provided by Godwell Nhamo in his paper in this edition of the journal. He provides a description of the possibilities that actor network theory provides for describing and explaining environmental policy processes, and recommends that environmental educators consider this methodology in their analyses. In particular, he refers environmental educators to applications of actor network theory for tracing relational dynamics between actors (i.e., environmental education practitioners) and actants which are non-human referents (e.g., the UN Decade of Education for Sustainable Development and UNESCO’s (2005) International Implementation Scheme). In response to his paper, I have chosen to ‘pick up’ on this methodological discussion in this Editorial, by considering aspects of this theoretical perspective in describing the ‘happenings’ that occur across the pages of this edition of the EEASA Journal. In doing so, I highlight (in part) the diversity of actors and actants that are influencing the field of environmental education, their subject matter and contexts, and I highlight the relational dynamics that become evident when one accepts a methodology that aims to trace such dynamics. In particular, this Editorial considers how ‘The language of actors, actants and actor/actant-networks brings to the fore the relationships and complexities that exist around them’ (Nhamo, this edition).
- Full Text:
- Date Issued: 2006
Evaluation of Bacillus thuringiensis Berliner as an alternative control of small hive beetles, Aethina tumida Murray (Coleoptera: Nitidulidae)
- Buchholz, S, Neumann, Peter, Neumann, K, Hepburn, H Randall
- Authors: Buchholz, S , Neumann, Peter , Neumann, K , Hepburn, H Randall
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6929 , http://hdl.handle.net/10962/d1011945
- Description: Small hive beetles, Aethina tumida Murray, are parasites and scavengers of honeybee colonies, Apis mellifera L., and have become an invasive species that can cause considerable damage in its new distribution areas. An effective subspecies of Bacillus thuringiensis Berliner (=Bt) would provide an alternative to chemical control of this pest. Therefore, we tested three different Bt strains [B. thuringiensis, var. aizawai (B401®), B. thuringiensis var. kurstaki (Novodor®) and B. thuringiensis var. San Diego tenebrionis (Jackpot®)] and Perizin® (3.2% coumaphos), each applied on combs with a pollen diet fed to pairs of adult beetles. This evaluates the products for the suppression of successful small hive beetle reproduction. While none of the tested Bt strains showed a significant effect on the number of produced wandering larvae, we could confirm the efficacy of coumaphos for the control of small hive beetles. We further show that it is also efficient when applied with a lower concentration as a liquid on the combs. We suggest the continued search for efficient Bt strains naturally infesting small hive beetles in its endemic and new ranges, which may become a part of the integrated management of this pest.
- Full Text:
- Date Issued: 2006
- Authors: Buchholz, S , Neumann, Peter , Neumann, K , Hepburn, H Randall
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6929 , http://hdl.handle.net/10962/d1011945
- Description: Small hive beetles, Aethina tumida Murray, are parasites and scavengers of honeybee colonies, Apis mellifera L., and have become an invasive species that can cause considerable damage in its new distribution areas. An effective subspecies of Bacillus thuringiensis Berliner (=Bt) would provide an alternative to chemical control of this pest. Therefore, we tested three different Bt strains [B. thuringiensis, var. aizawai (B401®), B. thuringiensis var. kurstaki (Novodor®) and B. thuringiensis var. San Diego tenebrionis (Jackpot®)] and Perizin® (3.2% coumaphos), each applied on combs with a pollen diet fed to pairs of adult beetles. This evaluates the products for the suppression of successful small hive beetle reproduction. While none of the tested Bt strains showed a significant effect on the number of produced wandering larvae, we could confirm the efficacy of coumaphos for the control of small hive beetles. We further show that it is also efficient when applied with a lower concentration as a liquid on the combs. We suggest the continued search for efficient Bt strains naturally infesting small hive beetles in its endemic and new ranges, which may become a part of the integrated management of this pest.
- Full Text:
- Date Issued: 2006
Implementing the GrabCut segmentation technique as a plugin for the GIMP
- Marsh, Matthew, Bangay, Shaun D, Lobb, Adele
- Authors: Marsh, Matthew , Bangay, Shaun D , Lobb, Adele
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/433207 , vital:72951 , https://doi.org/10.1145/1108590.1108618
- Description: Image segmentation requires a segmentation tool that is fast and easy to use. The GIMP has built in segmentation tools, but under some circumstances these tools perform badly. "GrabCut" is an innovative segmentation technique that uses both region and boundary information in order to perform segmentation. Several variations on the "GrabCut" algorithm have been implemented as a plugin for the GIMP. The results obtained using "GrabCut" are comparable, and often better than the results of all the other built in segmentation tools.
- Full Text:
- Date Issued: 2006
- Authors: Marsh, Matthew , Bangay, Shaun D , Lobb, Adele
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/433207 , vital:72951 , https://doi.org/10.1145/1108590.1108618
- Description: Image segmentation requires a segmentation tool that is fast and easy to use. The GIMP has built in segmentation tools, but under some circumstances these tools perform badly. "GrabCut" is an innovative segmentation technique that uses both region and boundary information in order to perform segmentation. Several variations on the "GrabCut" algorithm have been implemented as a plugin for the GIMP. The results obtained using "GrabCut" are comparable, and often better than the results of all the other built in segmentation tools.
- Full Text:
- Date Issued: 2006
Interactions of fishes with particular reference to coelacanths in the canyons at Sodwana Bay and the St Lucia Marine Protected Area of South Africa
- Heemstra, Phillip C, Frickle, H, Hissmann, K
- Authors: Heemstra, Phillip C , Frickle, H , Hissmann, K
- Date: 2006
- Language: English
- Type: text , Article
- Identifier: vital:7130 , http://hdl.handle.net/10962/d1011771
- Description: The deep demersal fish fauna at depths of 100–400min canyons off the St Lucia Marine Protected Area along the north coast of KwaZulu-Natal is compared with similar fish communities at the Comoro Islands and in the Indo-Pacific region. Fifty-four fish species were seen or photographed from the submersible Jago or by the discovery team of scuba divers in the coelacanth, Latimeria chalumnae, habitat of the canyons off Sodwana Bay. An additional 94 fish species known from depths of 100–200 m along the coast of northern KwaZulu-Natal are likely to occur in the canyon habitat. The fish fauna of the Sodwana canyons shares at least 18 species with the deep demersal fish community off tropical coral reefs of the Indo-Pacific region. Thirty-seven of the Sodwana canyon fishes are also known from the coelacanth habitat in the Comoros.
- Full Text:
- Date Issued: 2006
- Authors: Heemstra, Phillip C , Frickle, H , Hissmann, K
- Date: 2006
- Language: English
- Type: text , Article
- Identifier: vital:7130 , http://hdl.handle.net/10962/d1011771
- Description: The deep demersal fish fauna at depths of 100–400min canyons off the St Lucia Marine Protected Area along the north coast of KwaZulu-Natal is compared with similar fish communities at the Comoro Islands and in the Indo-Pacific region. Fifty-four fish species were seen or photographed from the submersible Jago or by the discovery team of scuba divers in the coelacanth, Latimeria chalumnae, habitat of the canyons off Sodwana Bay. An additional 94 fish species known from depths of 100–200 m along the coast of northern KwaZulu-Natal are likely to occur in the canyon habitat. The fish fauna of the Sodwana canyons shares at least 18 species with the deep demersal fish community off tropical coral reefs of the Indo-Pacific region. Thirty-seven of the Sodwana canyon fishes are also known from the coelacanth habitat in the Comoros.
- Full Text:
- Date Issued: 2006