Establishment of translocated populations of smallmouth yellowfish, Labeobarbus aeneus (Pisces: Cyprinidae), in lentic and lotic habitats in the Great Fish River system, South Africa
- Weyl, Olaf L F, Stadtlander, Timo, Booth, Anthony J
- Authors: Weyl, Olaf L F , Stadtlander, Timo , Booth, Anthony J
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124418 , vital:35607 , https://doi.org/10.3377/004.044.0109
- Description: As a result of numerous introductions and translocations of fishes, South Africa has recently been identified as a fish invasion hotspot (Leprieur et al. 2008). In freshwater ecosystems invasion by alien species is considered a leading mechanism driving environmental change (Clavero & Garcia- Berthou 2005; Garcia-Berthou et al. 2005). In South Africa, documented effects of fish invasions include the extirpation of indigenous fishes through predation (Cambray 2003), changes in invertebrate community structure (Lowe et al. 2008) and hybridization (Canonico et al. 2005). As a result, the management of alien species is a high national priority (National Environmental Management: Biodiversity Act 2004). Such management requires an understanding of the biology, ecology and establishment success of fishes outside their native range.
- Full Text:
- Date Issued: 2009
- Authors: Weyl, Olaf L F , Stadtlander, Timo , Booth, Anthony J
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124418 , vital:35607 , https://doi.org/10.3377/004.044.0109
- Description: As a result of numerous introductions and translocations of fishes, South Africa has recently been identified as a fish invasion hotspot (Leprieur et al. 2008). In freshwater ecosystems invasion by alien species is considered a leading mechanism driving environmental change (Clavero & Garcia- Berthou 2005; Garcia-Berthou et al. 2005). In South Africa, documented effects of fish invasions include the extirpation of indigenous fishes through predation (Cambray 2003), changes in invertebrate community structure (Lowe et al. 2008) and hybridization (Canonico et al. 2005). As a result, the management of alien species is a high national priority (National Environmental Management: Biodiversity Act 2004). Such management requires an understanding of the biology, ecology and establishment success of fishes outside their native range.
- Full Text:
- Date Issued: 2009
Juvenile population dynamics of Oreochromis mossambicus in an intermittently open estuary at the limit of its natural distribution
- Ellender, Bruce R, Weyl, Olaf L F, Shanyengange, M K, Cowley, Paul D
- Authors: Ellender, Bruce R , Weyl, Olaf L F , Shanyengange, M K , Cowley, Paul D
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/446893 , vital:74568 , https://doi.org/10.1080/15627020.2008.11657245
- Description: Juvenile Oreochromis mossambicus in the 25 ha, temperate, intermittently open, East Kleinemonde Estuary in the Eastern Cape, South Africa (33°32’S, 27°03’E), showed a seasonal shift in distribution, occupying all areas of the estuary in summer and, subsequently, being limited to the upper reaches in winter. The young of the year in the littoral zone were rapidly depleted and resultant estimates of the instantaneous rate of total mortality (Z) ranged from 5.4/yr to 6.9/yr. High annual rates of juvenile mortality and small adult populations imply that stock recovery after a reduction in adult population numbers, through activities such as fishing, may be slow. This work adds to the knowledge base of O. mossambicus ecology and population dynamics in temperate estuaries at the limit of its natural distribution.
- Full Text:
- Date Issued: 2008
- Authors: Ellender, Bruce R , Weyl, Olaf L F , Shanyengange, M K , Cowley, Paul D
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/446893 , vital:74568 , https://doi.org/10.1080/15627020.2008.11657245
- Description: Juvenile Oreochromis mossambicus in the 25 ha, temperate, intermittently open, East Kleinemonde Estuary in the Eastern Cape, South Africa (33°32’S, 27°03’E), showed a seasonal shift in distribution, occupying all areas of the estuary in summer and, subsequently, being limited to the upper reaches in winter. The young of the year in the littoral zone were rapidly depleted and resultant estimates of the instantaneous rate of total mortality (Z) ranged from 5.4/yr to 6.9/yr. High annual rates of juvenile mortality and small adult populations imply that stock recovery after a reduction in adult population numbers, through activities such as fishing, may be slow. This work adds to the knowledge base of O. mossambicus ecology and population dynamics in temperate estuaries at the limit of its natural distribution.
- Full Text:
- Date Issued: 2008
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