Richard and Kathy, Gene and Rachel finished their southern African travels at the Imbabala Safari Lodge in Zimbabwe, located on the bank of the Zambezi River about 70 km (45 m.) upstream of Victoria Falls. River cruises and land drives showed them impala, warthogs, elephants, Kudu, monitor lizards, crocodiles, hippos and bush bucks. As you will see in Kathy’s Smilebox, this safari lodge is a nice spot to stay.
There’s 2 things going on here. First is that the crocodiles in Kruger Park’s Olifants and Letaba Rivers started dying off in the winter of 2008 – 170 of them found dead from May to November that year, an unknown additional number dead and washed away or eaten by their colleagues. Pansteatitis, an inflammation of fatty tissue and conversion to a form that cannot be metabolized was the problem. But what caused the pansteatitis or created the internal stress that allowed the disease to take hold? Retrospective analysis of 2007 samples from live crocs showed the first signs of the disease in the population. Investigators began contemplating upstream influences; pollution from upstream industrial and agricultural sources. This caught my interest as a former water quality fisheries biologist responsible for investigating “spills, kills and thrills” on Vancouver Island. Also, neighbouring Mozambique had activated a downstream dam that backed up water settling large quantities of silt.
The second thing that is going on, is that new reports of crocodile mortality have disappeared from the web and media and largely from public attention. A Google News search at this time (Feb. 2013) turns up no new references. A broader Google search for web sites turns up mostly old news from 2008 and 2009. For example, there is the South African National Parks official website archived news media release from June 2009 indicating that deaths had resumed that year. Searching the SanParks website turns up a scientific presentation at the 8th Annual Savanna Science Network Meeting of 2010 confirming that the mortality cycle was repeated in 2009. Also see the article in the Scientific American, Oct. 2009. But where are the media updates and news releases since then? Noticeably absent. The exception is a private web article What is killing South Africas crocs by HopeOnline dated June 2012 although it is difficult to determine what period the information in that article refers to.
Has the mortality cycle stopped? Or has the national parks service bureaucracy muzzled the researchers? After all, it reflects poorly if one of their park’s major predators is dying off in large numbers – one estimate was that 60% were “missing” from some areas of the park. Reports like that could affect tourism or draw unwelcome attention from conservation groups. Or maybe the government itself finds the topic of the potential impacts of a dam in a neighbouring allied country, or of possible unmanageable sources of pollution from upstream industrial and agricultural interests to be too sensitive to discuss in public? If you have links to more recent information about crododile deaths in Kruger Park, please pass them back this way. I’m still looking for it.
Found another item: CSIR Researchspace reference to a publication attributing the crocodile deaths to dam enhanced populations of an unidentified fish species that is somehow encouraging pansteatitis development in crocs and piscivorous fishes. On the other hand, a crocodile husbandry publication indicates on page 219 that steatitis fat necrosis may result from vitamin E deficiency.
Rhinos. Will rhinos be gone from Kruger Park by 2020?. This IOL News Jan. 6 article by Simon Bloch and Ivor Powell reviews a journal publication by Dr Sam Ferreira, large mammal ecologist for SANParks at Kruger National Park. From previous posts you know that I am aware of the rhino poaching problem in southern Africa, more than 600 last year. Poaching rates have increased, 48% higher in Kruger Park in 2012 than 2011. The Western Black Rhinocerus subspecies, officially declared in 2011 to be extinct. The last known specimen of the Asian rhinocerus, killed in Viet Nam in 2010. Only 4 rhinos may still survive in the Hwange National Park in Zimbabwe, alleged to be collateral damage from Chinese mining concessions and the influx of Asian immigrants in that country. Read about the poaching links to “The Crocodile” Emmerson Mnangagwa also referred to as “The Butcher of Matabeleland”. The architect of Zimbabwe’s state security and creator of Zimbabwe’s Central Intelligence Office – possible in line for president after Robert Mugabe. I stumbled across this article accidentally when I was looking for an update about pollution related Kruger Park crocodile deaths in 2010 and 2011 and thinking of anthrax killing off hippos – posts for another day. I post this here, hoping that the article will not be lost in the tsunami of daily news and that the data will not remain buried in scientific journals.
Jan. 24 from BBC News Africa, 15000 crocodiles escaped a farm during flooding in northern South Africa near the Limpopo River: http://www.bbc.co.uk/news/world-africa-21178793
Jan. 25 Update from the Globe and Mail, police are called out to help with crocodile recovery hunt, near border with Botswana and Zimbabwe.
Jan. 26 Update from BBC News , have the crocs spread 120 km. downstream?