H. Bouwman*1, D. Govender2, L.G. Underhill3, A. Polder4 1North-West University, Potchefstroom, So... more H. Bouwman*1, D. Govender2, L.G. Underhill3, A. Polder4 1North-West University, Potchefstroom, South Africa; 2SANParks, Skukuza, South Africa; 3University of Cape Town, Cape Town, South Africa; 4The Norwegian School for Veterinary Sciences, Oslo, Norway. henk.bouwman@nwu.ac.za Levels of pollutants in penguin eggs from the Antarctic are relatively well known. However, the most recent assessment of pollutants in eggs of the African Penguin Spheniscus demersus on the south coast of Africa was about three decades ago. We collected 10 eggs each from Robben Island near Cape Town and from Bird Island near Port Elizabeth, about 840 km further east. For HCB, ΣHCH, Σchlordanes, ΣDDT, mirex, PCBs, Σtoxaphenes and PBDEs, the mean levels from Robben Island were always lower than from Bird Island (t-test; p<0.05). For ΣHCH, ΣDDT, mirex, ΣPCBs and Σtoxaphenes, the differences were less (t-test; p>0.05). Mean ΣDDT were 310 ng/g lipid at Robben Island, and 630 ng/g lipid at Bird Island. PCBs w...
Trichinella zimbabwensis has been found naturally infecting crocodiles (Crocodylus niloticus) in ... more Trichinella zimbabwensis has been found naturally infecting crocodiles (Crocodylus niloticus) in Zimbabwe, Mozambique, Ethiopia and South Africa, as well as monitor lizards (Varanus niloticus) in Zimbabwe. The reports on natural infections were mostly accidental rather than structured surveys and involved very few animals. Previous surveillance studies in South Africa reported a 38.5% prevalence of T. zimbabwensis among wild crocodiles tested from the Mpumalanga province and Kruger National Park (KNP). No studies have been conducted to date on the geographical distribution and occurrence of T. zimbabwensis in wild crocodiles and varans in countries in southern Africa. Recent outbreaks of pansteatitis in crocodile populations of the KNP, South Africa, provided an opportunity to conduct a more structured survey aimed at elucidating the occurrence and distribution of T. zimbabwensis in culled wild crocodile populations within the KNP. Results from this study showed that T. zimbabwensis occurred in 10 out of 12 culled crocodiles form the KNP. The results also showed that the natural distribution of T. zimbabwensis in crocodiles includes all the major river systems in the KNP. The predilection sites of larvae in muscles followed a different pattern in naturally infected crocodiles compared to observations in experimentally infected mammalian hosts.
Based on previous necropsy results, Microcystis blooms in constructed water impoundments in the K... more Based on previous necropsy results, Microcystis blooms in constructed water impoundments in the Kruger National Park (KNP) have been identified as a cause of wildlife mortality. In response to wildlife mortality during 2007, water samples, containing algal bloom material, were collected during February 2007 and July 2007 from four dams (Nhlanganzwani, Mpanamana, Makhohlola, and Sunset) in the southeastern part of the KNP as part of the follow-up investigation. The toxicity of the Microcystis blooms was determined using the enzyme-linked immunosorbent assay (ELISA), protein phosphatase inhibition (PPI) assay, mouse bioassay, and African sharptooth catfish (Clarias gariepinus) primary hepatocytes. Both the ELISA and PPI assays indicated that the water sample collected during February 2007 from the Nhlanganzwani Dam, and samples collected from the Nhlanganzwani and Sunset dams in June 2007, were toxic. These dams, exhibiting the toxic Microcystis blooms, were also associated with the wildlife mortality. Mice injected intraperitoneally with water samples from Nhlanganzwani Dam (February 2007) induced hepatotoxicity and mortality within 1 hr. Primary hepatocytes from the sharptooth catfish exposed to samples from these dams gave similar results. This laboratory investigation and results strongly incriminate the toxic Microcystis blooms as the cause of the wildlife mortality. Eutrophication and bloom formation appear to have been the consequence of the high numbers of hippopotami (Hippopotamus amphibius) in specific dams.
H. Bouwman*1, D. Govender2, L.G. Underhill3, A. Polder4 1North-West University, Potchefstroom, So... more H. Bouwman*1, D. Govender2, L.G. Underhill3, A. Polder4 1North-West University, Potchefstroom, South Africa; 2SANParks, Skukuza, South Africa; 3University of Cape Town, Cape Town, South Africa; 4The Norwegian School for Veterinary Sciences, Oslo, Norway. henk.bouwman@nwu.ac.za Levels of pollutants in penguin eggs from the Antarctic are relatively well known. However, the most recent assessment of pollutants in eggs of the African Penguin Spheniscus demersus on the south coast of Africa was about three decades ago. We collected 10 eggs each from Robben Island near Cape Town and from Bird Island near Port Elizabeth, about 840 km further east. For HCB, ΣHCH, Σchlordanes, ΣDDT, mirex, PCBs, Σtoxaphenes and PBDEs, the mean levels from Robben Island were always lower than from Bird Island (t-test; p<0.05). For ΣHCH, ΣDDT, mirex, ΣPCBs and Σtoxaphenes, the differences were less (t-test; p>0.05). Mean ΣDDT were 310 ng/g lipid at Robben Island, and 630 ng/g lipid at Bird Island. PCBs w...
Trichinella zimbabwensis has been found naturally infecting crocodiles (Crocodylus niloticus) in ... more Trichinella zimbabwensis has been found naturally infecting crocodiles (Crocodylus niloticus) in Zimbabwe, Mozambique, Ethiopia and South Africa, as well as monitor lizards (Varanus niloticus) in Zimbabwe. The reports on natural infections were mostly accidental rather than structured surveys and involved very few animals. Previous surveillance studies in South Africa reported a 38.5% prevalence of T. zimbabwensis among wild crocodiles tested from the Mpumalanga province and Kruger National Park (KNP). No studies have been conducted to date on the geographical distribution and occurrence of T. zimbabwensis in wild crocodiles and varans in countries in southern Africa. Recent outbreaks of pansteatitis in crocodile populations of the KNP, South Africa, provided an opportunity to conduct a more structured survey aimed at elucidating the occurrence and distribution of T. zimbabwensis in culled wild crocodile populations within the KNP. Results from this study showed that T. zimbabwensis occurred in 10 out of 12 culled crocodiles form the KNP. The results also showed that the natural distribution of T. zimbabwensis in crocodiles includes all the major river systems in the KNP. The predilection sites of larvae in muscles followed a different pattern in naturally infected crocodiles compared to observations in experimentally infected mammalian hosts.
Based on previous necropsy results, Microcystis blooms in constructed water impoundments in the K... more Based on previous necropsy results, Microcystis blooms in constructed water impoundments in the Kruger National Park (KNP) have been identified as a cause of wildlife mortality. In response to wildlife mortality during 2007, water samples, containing algal bloom material, were collected during February 2007 and July 2007 from four dams (Nhlanganzwani, Mpanamana, Makhohlola, and Sunset) in the southeastern part of the KNP as part of the follow-up investigation. The toxicity of the Microcystis blooms was determined using the enzyme-linked immunosorbent assay (ELISA), protein phosphatase inhibition (PPI) assay, mouse bioassay, and African sharptooth catfish (Clarias gariepinus) primary hepatocytes. Both the ELISA and PPI assays indicated that the water sample collected during February 2007 from the Nhlanganzwani Dam, and samples collected from the Nhlanganzwani and Sunset dams in June 2007, were toxic. These dams, exhibiting the toxic Microcystis blooms, were also associated with the wildlife mortality. Mice injected intraperitoneally with water samples from Nhlanganzwani Dam (February 2007) induced hepatotoxicity and mortality within 1 hr. Primary hepatocytes from the sharptooth catfish exposed to samples from these dams gave similar results. This laboratory investigation and results strongly incriminate the toxic Microcystis blooms as the cause of the wildlife mortality. Eutrophication and bloom formation appear to have been the consequence of the high numbers of hippopotami (Hippopotamus amphibius) in specific dams.
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