Videographic analysis of the Coelacanth, Latimeria Chalumnae, and associated habitats in the Isimangaliso Wetland Park, KwaZulu-Natal, South Africa
- Thornycroft, Rosanne Elizabeth
- Authors: Thornycroft, Rosanne Elizabeth
- Date: 2012
- Subjects: Isimangaliso Wetland Park , Coelacanth , Coelacanth -- South Africa -- KwaZulu-Natal , Habitat (Ecology) , Coelacanth -- Behavior -- South Africa -- KwaZulu-Natal , Coelacanth -- Habitat -- South Africa -- KwaZulu-Natal
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5333 , http://hdl.handle.net/10962/d1005179 , Isimangaliso Wetland Park , Coelacanth , Coelacanth -- South Africa -- KwaZulu-Natal , Habitat (Ecology) , Coelacanth -- Behavior -- South Africa -- KwaZulu-Natal , Coelacanth -- Habitat -- South Africa -- KwaZulu-Natal
- Description: Videography is a valuable tool in biological and ecological studies. Using video footage obtained during previous coelacanth surveys, this thesis investigated coelacanths and their associated habitats in the submarine canyons of iSimangaliso Wetland Park, South Africa. This thesis aimed to (1) describe the biological habitats within the submarine canyons, (2) determine coelacanth distribution within these habitats, and (3) assess the use of computer-aided identification to successfully identify individual coelacanths. Seven different habitat types were noted with the most distinctive being the canyon margins that consisted of dense agglomerations of gorgonians, wire and whip corals, and sponges. Results suggested that although substratum type has a great influence on invertebrate community structure in the canyons, depth is the principal factor. Coelacanths were associated with cave habitats within the steep rocky canyon walls. Habitat analyses allowed predictive classification tree models to be constructed. Depth, underlying percentage of rock, and percentage cover of gorgonians and sponges were the most important variables for determining coelacanth presence and absence. The overall correct classification rate for the model was estimated at 96.6%, correctly predicting coelacanth absence (> 99%) better than presence (60%). Because coelacanths have a unique spot pattern it was possible to quickly and accurately identify specific individuals photographically using computer-aided identification software. Without any manual intervention by an operator the software accurately identified between 56 and 92% of the individuals. Identification success increased to 100% if the operator could also manually select from other potential matching photographs. It was also shown that fish exhibiting a yaw angle not exceeding 60° could be accurately identified in photographs. Each of the sections presented in this thesis represent a possible step towards analysing coelacanth-related habitats, locating and then analysing new habitats. Steps include first locating a population and then performing a habitat analysis. Coelacanth location within the different habitats can then be determined allowing the development of predictive models to potentially identify possible locations of new populations. The final step is to identify individual fish within the population for assessing demographic parameters and population monitoring.
- Full Text:
- Date Issued: 2012
- Authors: Thornycroft, Rosanne Elizabeth
- Date: 2012
- Subjects: Isimangaliso Wetland Park , Coelacanth , Coelacanth -- South Africa -- KwaZulu-Natal , Habitat (Ecology) , Coelacanth -- Behavior -- South Africa -- KwaZulu-Natal , Coelacanth -- Habitat -- South Africa -- KwaZulu-Natal
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5333 , http://hdl.handle.net/10962/d1005179 , Isimangaliso Wetland Park , Coelacanth , Coelacanth -- South Africa -- KwaZulu-Natal , Habitat (Ecology) , Coelacanth -- Behavior -- South Africa -- KwaZulu-Natal , Coelacanth -- Habitat -- South Africa -- KwaZulu-Natal
- Description: Videography is a valuable tool in biological and ecological studies. Using video footage obtained during previous coelacanth surveys, this thesis investigated coelacanths and their associated habitats in the submarine canyons of iSimangaliso Wetland Park, South Africa. This thesis aimed to (1) describe the biological habitats within the submarine canyons, (2) determine coelacanth distribution within these habitats, and (3) assess the use of computer-aided identification to successfully identify individual coelacanths. Seven different habitat types were noted with the most distinctive being the canyon margins that consisted of dense agglomerations of gorgonians, wire and whip corals, and sponges. Results suggested that although substratum type has a great influence on invertebrate community structure in the canyons, depth is the principal factor. Coelacanths were associated with cave habitats within the steep rocky canyon walls. Habitat analyses allowed predictive classification tree models to be constructed. Depth, underlying percentage of rock, and percentage cover of gorgonians and sponges were the most important variables for determining coelacanth presence and absence. The overall correct classification rate for the model was estimated at 96.6%, correctly predicting coelacanth absence (> 99%) better than presence (60%). Because coelacanths have a unique spot pattern it was possible to quickly and accurately identify specific individuals photographically using computer-aided identification software. Without any manual intervention by an operator the software accurately identified between 56 and 92% of the individuals. Identification success increased to 100% if the operator could also manually select from other potential matching photographs. It was also shown that fish exhibiting a yaw angle not exceeding 60° could be accurately identified in photographs. Each of the sections presented in this thesis represent a possible step towards analysing coelacanth-related habitats, locating and then analysing new habitats. Steps include first locating a population and then performing a habitat analysis. Coelacanth location within the different habitats can then be determined allowing the development of predictive models to potentially identify possible locations of new populations. The final step is to identify individual fish within the population for assessing demographic parameters and population monitoring.
- Full Text:
- Date Issued: 2012
An assessment of habitat suitability of the proposed Tyefu community game reserve in Ngqushwa (fomerly Peddie) district, Eastern Cape
- Authors: Mamfengu, Phozisa Faith
- Date: 2007
- Subjects: Game farms -- South Africa -- Eastern Cape -- Management , Habitat (Ecology) , Eastern Cape (South Africa) -- Social conditions
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10653 , http://hdl.handle.net/10948/736 , Game farms -- South Africa -- Eastern Cape -- Management , Habitat (Ecology) , Eastern Cape (South Africa) -- Social conditions
- Description: Land use forms such as cultivation and livestock farming have become less productive and unsustainable in the Tyefu communal villages of Ngqushwa (Formerly Peddie) district, Eastern Cape, South Africa. This is manifest in abandoned and severely degraded cultivation fields as well as transformed vegetation, making it difficult to earn a land based livelihood. Against the backdrop of severe land degradation and poverty levels in these communal villages, game farming has been recommended as an ecologically, economically and socially sustainable form of land use. Tyefu Community Reserve is a project, recommended by the Subtropical Thicket Ecosystem Project (STEP) backed by the Department of Environment Affairs and Tourism (DEAT), for hunting and venison selling. The proposed area has been fenced and animals to be stocked in the reserve have been requested on a loan basis. Such an undertaking requires an understanding of the abundance and condition of vegetation, terrain parameters, and an assessment of potential wildlife species, as well as the carrying capacity of the recommended reserve as a habitat. With the aid of orthophoto maps, Subtropical Thicket Ecosystem Planning (STEP) shapefiles, ASTER satellite imagery and a High Resolution Digital Camera Image, vegetation types were mapped and their condition was assessed. A Digital Elevation Model (DEM) of the area was used to extract terrain parameters such as slope and aspect. The carrying capacity of the proposed reserve was determined using a model originally developed by Boshoff et al. (2001) for estimating potential wildlife and abundance. The proposed reserve is predominantly covered by dense thicket as compared to the adjacent Tyefu communal villages where thicket has been severely degraded. The prominent topographic characteristics such as slope reveal an escarpment ringing the proposed reserve with gentle slopes towards the centre. Slope direction has also influenced the distribution of vegetation in the proposed reserve, as the moist south facing slopes tend to have a greater proportion of dense thicket as opposed to the warm north facing slopes. Vegetation types and topography of the reserve can provide suitable habitat to a variety of wildlife species and are likely to influence the distribution of mammals in the proposed reserve. The carrying capacity model developed has been useful in determining potential species that can be supported by the reserve, and estimating their abundance. Given the small size of the proposed community reserve (about 1800ha), it has been recommended that it should be stretched to link up with the existing Great Fish River Game Complex. It will then fit within the framework as envisaged by STEP (2004), in the form of Fish River Biodiversity Initiative, a conservation corridor bordering the Great Fish River.
- Full Text:
- Date Issued: 2007
- Authors: Mamfengu, Phozisa Faith
- Date: 2007
- Subjects: Game farms -- South Africa -- Eastern Cape -- Management , Habitat (Ecology) , Eastern Cape (South Africa) -- Social conditions
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10653 , http://hdl.handle.net/10948/736 , Game farms -- South Africa -- Eastern Cape -- Management , Habitat (Ecology) , Eastern Cape (South Africa) -- Social conditions
- Description: Land use forms such as cultivation and livestock farming have become less productive and unsustainable in the Tyefu communal villages of Ngqushwa (Formerly Peddie) district, Eastern Cape, South Africa. This is manifest in abandoned and severely degraded cultivation fields as well as transformed vegetation, making it difficult to earn a land based livelihood. Against the backdrop of severe land degradation and poverty levels in these communal villages, game farming has been recommended as an ecologically, economically and socially sustainable form of land use. Tyefu Community Reserve is a project, recommended by the Subtropical Thicket Ecosystem Project (STEP) backed by the Department of Environment Affairs and Tourism (DEAT), for hunting and venison selling. The proposed area has been fenced and animals to be stocked in the reserve have been requested on a loan basis. Such an undertaking requires an understanding of the abundance and condition of vegetation, terrain parameters, and an assessment of potential wildlife species, as well as the carrying capacity of the recommended reserve as a habitat. With the aid of orthophoto maps, Subtropical Thicket Ecosystem Planning (STEP) shapefiles, ASTER satellite imagery and a High Resolution Digital Camera Image, vegetation types were mapped and their condition was assessed. A Digital Elevation Model (DEM) of the area was used to extract terrain parameters such as slope and aspect. The carrying capacity of the proposed reserve was determined using a model originally developed by Boshoff et al. (2001) for estimating potential wildlife and abundance. The proposed reserve is predominantly covered by dense thicket as compared to the adjacent Tyefu communal villages where thicket has been severely degraded. The prominent topographic characteristics such as slope reveal an escarpment ringing the proposed reserve with gentle slopes towards the centre. Slope direction has also influenced the distribution of vegetation in the proposed reserve, as the moist south facing slopes tend to have a greater proportion of dense thicket as opposed to the warm north facing slopes. Vegetation types and topography of the reserve can provide suitable habitat to a variety of wildlife species and are likely to influence the distribution of mammals in the proposed reserve. The carrying capacity model developed has been useful in determining potential species that can be supported by the reserve, and estimating their abundance. Given the small size of the proposed community reserve (about 1800ha), it has been recommended that it should be stretched to link up with the existing Great Fish River Game Complex. It will then fit within the framework as envisaged by STEP (2004), in the form of Fish River Biodiversity Initiative, a conservation corridor bordering the Great Fish River.
- Full Text:
- Date Issued: 2007
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