Botswana’s Mysterious Elephant Deaths Solved
After extensive testing, the Ministry of Wildlife and National Parks, Botswana, have now concluded that their elephants may have ingested toxins produced by bacteria found in waterholes.
Hundreds of elephants died earlier this year in Botswana from ingesting toxins produced by cyanobacteria, according to Government Officials. They said they will be testing waterholes for algal blooms next rainy season to reduce the risk of this happening again.
The mysterious death of 330 elephants in and around the Seronga region between May and June baffled conservationists and samples were taken and sent to laboratories around the world.
“Our latest tests have detected cyanobacterial neurotoxins to be the cause of deaths. These are bacteria found in water,” said Principal Veterinary Office, Mr Mmadi Reuben at a recent news conference. “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.”
Local sources suggest 70% of the elephants died near water holes containing algal blooms. These can produce toxic microscopic organisms called cyanobacteria. This was initially ruled out because no other wildlife had died – although one horse had died. Scientists now think that elephants could be particularly susceptible because they spend a lot of time bathing and drinking large quantities of water.
Mr Reuben explained that their investigations had looked into how mortality affected the elephant population and injuries on carcasses, along with testing water samples at laboratories in Botswana, South Africa and the US. The cause was found to be a “combination of neurotoxins”.
In August, 22 elephant carcasses were found between Hwange National Park and Victoria Falls in Zimbabwe. It is of concern that these could be linked to the elephant deaths across the border in Botswana. Zimbabwe authorities currently think their elephant deaths were caused by a bacterial infection. Samples have been sent to the UK for testing.
What are Cyanobacteria Toxins?
- Cyanobacteria is also known as blue-green algae. It is found worldwide, especially in calm, nutrient-rich waters
- Some species produce toxins that affect animals and humans
- People and animals may be exposed to cyanobacterial toxins by drinking or bathing in contaminated water
- Symptoms of Cyanobateria poisoning include skin irritation, stomach cramps, vomiting, nausea, diarrhoea, fever, sore throat and headaches
- It can be controlled by reducing the nutrient build-up (eutrophication) in lakes and reservoirs, especially by better management of wastewater disposal systems and control of pollution by fertilisers, including manure, from agriculture
You can find more information on Cyanobacteria Toxins on the WHO website