Assessment of microcystis bloom toxicity associated with wildlife mortality in the Kruger National Park, South Africa.
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.
Masango
Mxolisi G
MG
Division of Toxicology, Onderstepoort Veterinary Institute, Private Bag X05, Onderstepoort 0110, South Africa.
Myburgh
Jan G
JG
Labuschagne
Leonie
L
Govender
Danny
D
Bengis
Roy G
RG
Naicker
Dharmarai
D
D000818:Animals; D000835:Animals, Wild; D001681:Biological Assay; D002397:Catfishes; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004797:Enzyme-Linked Immunosorbent Assay; D005068:Eutrophication; D005260:Female; D005618:Fresh Water; D022781:Hepatocytes / Q000187:drug effects; D008297:Male; D051379:Mice; D052998:Microcystins / Q000494:pharmacology*; D046931:Microcystis / Q000737:chemistry*; D054648:Protein Phosphatase 2 / Q000037:antagonists & inhibitors / Q000378:metabolism; D013019:South Africa; D018675:Toxicity Tests / Q000662:veterinary*; D014871:Water Microbiology
D004791:Enzyme Inhibitors; D052998:Microcystins; D054648:Protein Phosphatase 2