On the underwater visual census of Western Indian Ocean coral reef fishes
- Authors: Wartenberg, Reece
- Date: 2012
- Subjects: Coral reef fishes -- Africa, Southern , Coral reef fishes -- Indian Ocean , Coral reef fishes -- Behavior , Fish communities -- Africa, Southern , Fish communities -- Indian Ocean , Groundfishes -- Africa, Southern , Groundfishes -- Indian Ocean , Groundfishes -- Behavior
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5308 , http://hdl.handle.net/10962/d1005153 , Coral reef fishes -- Africa, Southern , Coral reef fishes -- Indian Ocean , Coral reef fishes -- Behavior , Fish communities -- Africa, Southern , Fish communities -- Indian Ocean , Groundfishes -- Africa, Southern , Groundfishes -- Indian Ocean , Groundfishes -- Behavior
- Description: This study conducted the first high-resolution investigation of the ichthyofaunal assemblages on a high-latitude coral reef in the Western Indian Ocean (WIO). Two-Mile reef, in South Africa, is a large, accessible patch-reef, and was selected as a candidate study area. Although the effect of season in structuring coral reef fish communities is most-often overlooked, the relationship between these fish communities and their habitat structure has been investigated. In South Africa, however, neither of these potential community-level drivers has been explored. As coral reefs worldwide are faced with high levels of usage pressure, nondestructive underwater visual census (UVC) techniques were identified as the most appropriate survey methods. This study had two primary aims that were; (1) to identify the most suitable technique for the UVC of coral reef fishes, and to test variations of the selected technique for appropriateness to implementation in long-term monitoring programs, and (2) to determine if possible changes to ichthyofaunal community structure could be related to trends in season and/or habitat characteristics. A review of the literature indicated that the most appropriate UVC method for surveying epibenthic coral reef fishes is underwater transecting. To compare the traditional slate-based transects to variations that implement digital image technology, slate transects were compared to a first-attempt digital photographic transect technique, and digital videographic transects. Videographic transects produced the most favourable species richness, abundance, and standard deviations of the three techniques. Diversity was not significantly different between transect techniques. The minimum required sample size was lowest for videographic transects (17 replicates), intermediate for photographic transects (27 replicates) and highest for slate transects (37 replicates). Videographic and photographic transects required greater analysis time to generate counts, but required lower observer training time. While videographic transects produced the lowest proportion of species considered unidentifiable, all three transect techniques showed similar functionality to surveying epibenthic coral reef fishes. Videographic transects were therefore identified as the most appropriate UVC technique for this study. Videographic transects at shallow (6 – 14 m), intermediate (14 – 22 m) and deep (22 – 30 m) depths in mid-winter and mid-summer, sampled a total of 41 families consisting of 209 species and 18172 individuals, dominated by pomacentrids in abundance and labrids in richness. The fish assemblages on Two-Mile Reef were found to be similar in composition to lower-latitude WIO reefs. Overall ichthyofaunal abundance and richness was significantly higher in summer than in winter, and was higher at shallow sites than at intermediate and deep sites. A multivariate approach confirmed differences between seasons at shallow depths but not between seasons at intermediate and deep depths. The fish assemblages on Two-Mile Reef can therefore be described as being comprised of four relatively distinct communities: a shallow, winter community; a shallow, summer community; a year-round intermediate community; and a year-round deep community. The distributions of discriminating species indicated that high abundances of the algal-feeding pomacentrids are observed only at shallow and intermediate sites while high abundances of the zooplanktivorous serranid subfamily, the Anthiinae, are observed predominantly at deep sites. Assessment of all measured supplementary variables indicated that of all factor combinations, observed patterns could be ascribed most strongly to depth. Quantification of reef characteristics indicated that as depth increases, habitat complexity decreases, benthic communities shift from dense coral domination to sparse sponge domination, and algal biomass and cover decreases. The ability of the videographic transect technique to detect changes in community structure with season and depth indicates that season and depth should be accounted for in future high-latitude ichtyofaunal surveys, and that the videographic transect technique is suitable for implementation in long-term monitoring programs on coral reefs. The similarity in fish assemblages between Two-Mile Reef and lower latitude regions suggests that the protocol for surveying epibenthic coral reef fishes, resulting from this study, is relevant throughout the continental WIO.
- Full Text:
- Date Issued: 2012
- Authors: Wartenberg, Reece
- Date: 2012
- Subjects: Coral reef fishes -- Africa, Southern , Coral reef fishes -- Indian Ocean , Coral reef fishes -- Behavior , Fish communities -- Africa, Southern , Fish communities -- Indian Ocean , Groundfishes -- Africa, Southern , Groundfishes -- Indian Ocean , Groundfishes -- Behavior
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5308 , http://hdl.handle.net/10962/d1005153 , Coral reef fishes -- Africa, Southern , Coral reef fishes -- Indian Ocean , Coral reef fishes -- Behavior , Fish communities -- Africa, Southern , Fish communities -- Indian Ocean , Groundfishes -- Africa, Southern , Groundfishes -- Indian Ocean , Groundfishes -- Behavior
- Description: This study conducted the first high-resolution investigation of the ichthyofaunal assemblages on a high-latitude coral reef in the Western Indian Ocean (WIO). Two-Mile reef, in South Africa, is a large, accessible patch-reef, and was selected as a candidate study area. Although the effect of season in structuring coral reef fish communities is most-often overlooked, the relationship between these fish communities and their habitat structure has been investigated. In South Africa, however, neither of these potential community-level drivers has been explored. As coral reefs worldwide are faced with high levels of usage pressure, nondestructive underwater visual census (UVC) techniques were identified as the most appropriate survey methods. This study had two primary aims that were; (1) to identify the most suitable technique for the UVC of coral reef fishes, and to test variations of the selected technique for appropriateness to implementation in long-term monitoring programs, and (2) to determine if possible changes to ichthyofaunal community structure could be related to trends in season and/or habitat characteristics. A review of the literature indicated that the most appropriate UVC method for surveying epibenthic coral reef fishes is underwater transecting. To compare the traditional slate-based transects to variations that implement digital image technology, slate transects were compared to a first-attempt digital photographic transect technique, and digital videographic transects. Videographic transects produced the most favourable species richness, abundance, and standard deviations of the three techniques. Diversity was not significantly different between transect techniques. The minimum required sample size was lowest for videographic transects (17 replicates), intermediate for photographic transects (27 replicates) and highest for slate transects (37 replicates). Videographic and photographic transects required greater analysis time to generate counts, but required lower observer training time. While videographic transects produced the lowest proportion of species considered unidentifiable, all three transect techniques showed similar functionality to surveying epibenthic coral reef fishes. Videographic transects were therefore identified as the most appropriate UVC technique for this study. Videographic transects at shallow (6 – 14 m), intermediate (14 – 22 m) and deep (22 – 30 m) depths in mid-winter and mid-summer, sampled a total of 41 families consisting of 209 species and 18172 individuals, dominated by pomacentrids in abundance and labrids in richness. The fish assemblages on Two-Mile Reef were found to be similar in composition to lower-latitude WIO reefs. Overall ichthyofaunal abundance and richness was significantly higher in summer than in winter, and was higher at shallow sites than at intermediate and deep sites. A multivariate approach confirmed differences between seasons at shallow depths but not between seasons at intermediate and deep depths. The fish assemblages on Two-Mile Reef can therefore be described as being comprised of four relatively distinct communities: a shallow, winter community; a shallow, summer community; a year-round intermediate community; and a year-round deep community. The distributions of discriminating species indicated that high abundances of the algal-feeding pomacentrids are observed only at shallow and intermediate sites while high abundances of the zooplanktivorous serranid subfamily, the Anthiinae, are observed predominantly at deep sites. Assessment of all measured supplementary variables indicated that of all factor combinations, observed patterns could be ascribed most strongly to depth. Quantification of reef characteristics indicated that as depth increases, habitat complexity decreases, benthic communities shift from dense coral domination to sparse sponge domination, and algal biomass and cover decreases. The ability of the videographic transect technique to detect changes in community structure with season and depth indicates that season and depth should be accounted for in future high-latitude ichtyofaunal surveys, and that the videographic transect technique is suitable for implementation in long-term monitoring programs on coral reefs. The similarity in fish assemblages between Two-Mile Reef and lower latitude regions suggests that the protocol for surveying epibenthic coral reef fishes, resulting from this study, is relevant throughout the continental WIO.
- Full Text:
- Date Issued: 2012
An investigation of integrated development planning (IDP) as a mechanism for poverty alleviation in Grahamstown in the Makana Municipality, Eastern Cape, South Africa
- Authors: Alebiosu, Olumide Ademola
- Date: 2006
- Subjects: Makana Municipality , Local government -- South Africa -- Eastern Cape , Poor -- South Africa -- Eastern Cape , Poverty -- South Africa -- Eastern Cape , Poverty -- Government policy -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4841 , http://hdl.handle.net/10962/d1005517 , Makana Municipality , Local government -- South Africa -- Eastern Cape , Poor -- South Africa -- Eastern Cape , Poverty -- South Africa -- Eastern Cape , Poverty -- Government policy -- South Africa -- Eastern Cape
- Description: Poverty among individuals, households or communities is not a static condition. There are many factors which contribute to its causes and depth. In South Africa the economic gaps imposed by the previous apartheid government aggravated economic inequalities and caused considerable disparities, which has resulted in high unemployment rates. Inequalities were also manifest in the neglect of infrastructural and service provision as well in the effective absence of independent governance among some race group. This led to a call for pro-active initiatives by the post-1994 democratic government to remedy the living condition of the previously disadvantaged people. As part of its poverty relief drive the South African government has embarked on a series of developmental initiatives in bringing infrastructure related services to the poor and to reduce the enormous prevailing backlog, with the aim of increasing community participation, improving service delivery and promoting the upliftment of the lives of poor people through the medium of local governance. This study investigated the Integrated Development Planning, which has been undertaken in Grahamstown in the Makana Municipality in the Eastern Cape to respond to the prevailing poverty and underdevelopment among the poor communities. Relying on their developmental mandate to initiate and co-ordinate all development activities within their area of jurisdiction through the IDP, the Makana Municipality has drawn up a development strategic plan in conjunction with the local communities and with other stakeholders and organisations to identify and assess development backlogs within the communities with the aim of addressing such backlogs. This study revealed from the interviews conducted with some municipal personnel and questionnaires administered to sampled residents of Grahamstown that some faces of poverty, such as unemployment and lack of access to some of the most basic of infrastructure such as, sanitation facilities, water, electricity, formal house, education, security and recreation facilities are apparent in Grahamstown. However, the Makana Municipality through, the IDP has achieved some notable feats in the provision of providing some of the basic amenities such as water, housing, electricity and sanitation albeit at a slow rate. The mechanism of delivery is hampered by bureaucratic settings within government and the ambiguity attached to some of the projects. The service and infrastructural developments targeted towards the poor and the involvement of communities in the affairs of the local government might be seen as a partially panacea for poverty alleviation in South Africa. However the capacity of the local governments to effectively carry out this developmental challenge assignment might be a new twist in the developmental challenge facing local governments in South Africa. The thesis provides an overview of the Makana Municipality IDP and the degree to which is serving as one mechanism to address poverty in the Grahamstown urban area
- Full Text:
- Date Issued: 2006
- Authors: Alebiosu, Olumide Ademola
- Date: 2006
- Subjects: Makana Municipality , Local government -- South Africa -- Eastern Cape , Poor -- South Africa -- Eastern Cape , Poverty -- South Africa -- Eastern Cape , Poverty -- Government policy -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4841 , http://hdl.handle.net/10962/d1005517 , Makana Municipality , Local government -- South Africa -- Eastern Cape , Poor -- South Africa -- Eastern Cape , Poverty -- South Africa -- Eastern Cape , Poverty -- Government policy -- South Africa -- Eastern Cape
- Description: Poverty among individuals, households or communities is not a static condition. There are many factors which contribute to its causes and depth. In South Africa the economic gaps imposed by the previous apartheid government aggravated economic inequalities and caused considerable disparities, which has resulted in high unemployment rates. Inequalities were also manifest in the neglect of infrastructural and service provision as well in the effective absence of independent governance among some race group. This led to a call for pro-active initiatives by the post-1994 democratic government to remedy the living condition of the previously disadvantaged people. As part of its poverty relief drive the South African government has embarked on a series of developmental initiatives in bringing infrastructure related services to the poor and to reduce the enormous prevailing backlog, with the aim of increasing community participation, improving service delivery and promoting the upliftment of the lives of poor people through the medium of local governance. This study investigated the Integrated Development Planning, which has been undertaken in Grahamstown in the Makana Municipality in the Eastern Cape to respond to the prevailing poverty and underdevelopment among the poor communities. Relying on their developmental mandate to initiate and co-ordinate all development activities within their area of jurisdiction through the IDP, the Makana Municipality has drawn up a development strategic plan in conjunction with the local communities and with other stakeholders and organisations to identify and assess development backlogs within the communities with the aim of addressing such backlogs. This study revealed from the interviews conducted with some municipal personnel and questionnaires administered to sampled residents of Grahamstown that some faces of poverty, such as unemployment and lack of access to some of the most basic of infrastructure such as, sanitation facilities, water, electricity, formal house, education, security and recreation facilities are apparent in Grahamstown. However, the Makana Municipality through, the IDP has achieved some notable feats in the provision of providing some of the basic amenities such as water, housing, electricity and sanitation albeit at a slow rate. The mechanism of delivery is hampered by bureaucratic settings within government and the ambiguity attached to some of the projects. The service and infrastructural developments targeted towards the poor and the involvement of communities in the affairs of the local government might be seen as a partially panacea for poverty alleviation in South Africa. However the capacity of the local governments to effectively carry out this developmental challenge assignment might be a new twist in the developmental challenge facing local governments in South Africa. The thesis provides an overview of the Makana Municipality IDP and the degree to which is serving as one mechanism to address poverty in the Grahamstown urban area
- Full Text:
- Date Issued: 2006
Regulation of the indoleamines by sex steroids
- Authors: Awah, Edmund Kpabi
- Date: 1992
- Subjects: Steroids -- Research , Steroid drugs -- Research
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4053 , http://hdl.handle.net/10962/d1004114 , Steroids -- Research , Steroid drugs -- Research
- Description: Alteration of serum tryptophan leads to parallel alterations in brain tryptophan levels. Such changes in brain tryptophan levels has been shown to lead to mood disturbances. The primary enzyme responsible for altering serum tryptophan levels is the liver cytosolic enzyme, tryptophan pyrrolase. Activation of this enzyme is responsible for the enhanced catabolism of circulating tryptophan. The purpose of the present study was firstly to establish whether there is a link between sex steroids and tryptophan pyrrolase activity especially since sex steroids are also known to cause mood disturbances and secondly to determine the effects of sex steroids on brain indolamine metabolism. The results show that all three sex steroids induce the activity of tryptophan pyrrolase implying that they decrease serum tryptophan levels by the activation of tryptophan pyrrolase, thus making less tryptophan available for uptake by the brain. It was also shown that the sex steroids enhance the uptake of ¹⁴C-tryptophan by brain synatopsomes. In addition, the sex steroids influenced the pattern of metabolism of serotonin by organ cultures of rat pineal glands. It is possible that the sex steroids regulate the availability and uptake of indoleamines in the brain.
- Full Text:
- Date Issued: 1992
- Authors: Awah, Edmund Kpabi
- Date: 1992
- Subjects: Steroids -- Research , Steroid drugs -- Research
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4053 , http://hdl.handle.net/10962/d1004114 , Steroids -- Research , Steroid drugs -- Research
- Description: Alteration of serum tryptophan leads to parallel alterations in brain tryptophan levels. Such changes in brain tryptophan levels has been shown to lead to mood disturbances. The primary enzyme responsible for altering serum tryptophan levels is the liver cytosolic enzyme, tryptophan pyrrolase. Activation of this enzyme is responsible for the enhanced catabolism of circulating tryptophan. The purpose of the present study was firstly to establish whether there is a link between sex steroids and tryptophan pyrrolase activity especially since sex steroids are also known to cause mood disturbances and secondly to determine the effects of sex steroids on brain indolamine metabolism. The results show that all three sex steroids induce the activity of tryptophan pyrrolase implying that they decrease serum tryptophan levels by the activation of tryptophan pyrrolase, thus making less tryptophan available for uptake by the brain. It was also shown that the sex steroids enhance the uptake of ¹⁴C-tryptophan by brain synatopsomes. In addition, the sex steroids influenced the pattern of metabolism of serotonin by organ cultures of rat pineal glands. It is possible that the sex steroids regulate the availability and uptake of indoleamines in the brain.
- Full Text:
- Date Issued: 1992
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