Hundreds of elephants that died mysteriously in Botswana were killed by a toxic in their watering hole an investigation reveals.
More than 300 elephants were killed in Botswana earlier this year from toxins in water produced by cyanobacteria, officials said today.
They announced the results of the investigation into the deaths which had baffled and alarmed conservationists.
More than 300 elephants were killed in Botswana earlier this year from toxins in water produced by cyanobacteria
Locals in the area had reported seeing the elephants walking in circles suggesting they have been neurologically impaired either by a pathogen or a poison.
Cyanobacteria are microscopic organisms common in water and sometimes found in soil.
Not all produce toxins but scientists say toxic ones are occurring more frequently as climate change drives up global temperatures.
Cyril Taolo, deputy director of the Department of Wildlife and National Parks, told a news conference the number of dead elephants had risen to 330.
This was from 281 reported in July, where aerial photos showed their carcasses scattered across the Okavango Delta and other northern parts of the country.
The first unusual deaths were reported in May when 169 elephants died in a short period at the Okavango Delta, a marshy and lush wildlife habitat.
That number had almost doubled by mid June, with 70 per cent of the deaths occurring around waterholes, according to local sources.
Cyanobacteria are microscopic organisms common in water and sometimes found in soil that had poisoned the watering holes
The department’s principal veterinary officer Mmadi Reuben said: ‘Our latest tests have detected cyanobacterial neurotoxins to be the cause of deaths.
‘These are bacteria found in water.
‘However we have many questions still to be answered such as why the elephants only and why that area only? We have a number of hypotheses we are investigating.’
Other animals in the Okavango Panhandle region appeared unharmed.
Some cyanobacterial blooms can harm people and animals, with scientists becoming concerned about their potential impact due to climate change.
This leads to warmer water temperatures, which many cyanobacteria prefer.
Some cyanobacterial blooms can harm people as well as animals, with scientists becoming concerned about their potential impact due to climate change
Southern Africa’s temperatures are rising at twice the global average, according to the Intergovernmental Panel on Climate Change.
‘It amounts to having the right conditions, in the right time, in the right place and these species will proliferate,’ Patricia Glibert, a professor at the University of Maryland Center for Environmental Science, who has studied cyanobacteria.
‘These conditions are coming together more often, in more places, so we are seeing more of these toxic blooms around the world.’
In Zimbabwe, about 25 elephant carcasses were found near the country’s biggest game park and authorities suspect they succumbed to a bacterial infection.
The animals were found with tusks intact, ruling out poaching and deliberate poisoning.
The animals were found with tusks intact, ruling out poaching and deliberate poisoning
Parks authorities believe the elephants could have ingested the bacteria while searching for food and the carcasses were found near water sources.
‘We considered the possibility of cyanobacteria but we have no evidence that this is the case here (in Zimbabwe),’ said Chris Foggin, a veterinarian at the Victoria Falls Wildlife Trust.
It tested samples from both dead elephants from Zimbabwe and Botswana.
Zimbabwe has sent samples to Britain and is waiting for permits to send samples to two other countries, Foggin said.
Africa’s overall elephant population is declining due to poaching but Botswana, home to almost a third of the continent’s elephants, has seen numbers grow to around 130,000.