In late June, the world was alerted to the fact that hundreds of elephants in Botswana’s Okavango Delta were dropping dead in mysterious circumstances.

To add further mystery, some of the elephants appeared to die so rapidly that they simply fell forward onto their faces, with poaching ruled out due to the fact that the tusks had not been removed.

It wasn’t long before Carte Blanche was on the case, but at the time of their investigation, crucial test results were still being processed by various laboratories around the world.

Following months of speculation, we may finally have the answer as to what caused around 330 deaths, reports the Guardian:

Hundreds of elephants died in Botswana earlier this year from ingesting toxins produced by cyanobacteria, according to government officials who say they will be testing waterholes for algal blooms next rainy season to reduce the risk of another mass die-off…

“Our latest tests have detected cyanobacterial neurotoxins to be the cause of deaths. These are bacteria found in water,” Mmadi Reuben, principal veterinary officer at the Botswana department of wildlife and national parks, said in a news conference on Monday.

Image: Reuters

“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.”

Algal blooms can produce toxic microscopic organisms called cyanobacteria, and elephants may be particularly susceptible as they drink huge quantities of water each day, as well as spending time bathing in waterholes.

Dr Niall McCann, the director of conservation at UK-based charity National Park Rescue, has been involved in the process from the start of the story breaking.

He says that whilst he’s glad the findings “rule out some of the more sinister things”, there is still much to unpack from the findings:

“Just because cyanobacteria were found in the water that does not prove that the elephants died from exposure to those toxins. Without good samples from dead elephants, all hypotheses are just that: hypotheses,” said McCann.

Despite McCann’s scepticism, Cyril Taolo, the acting Director of Botswana’s Department of Wildlife and National Parks, was confident that the initial results pointed to cyanobacteria-related deaths.

This from CBC:

Taolo maintained neurotoxins from cyanobacteria living in contaminated water could have affected the transmission of neurologic signals within an animal, causing paralysis and death, predominately related to respiratory failure.

“Neurologic signs were reversed in an animal receiving an opiate antagonist during field immobilization, suggesting the clinical signs arose from some process affecting the animal’s neurologic receptors,” said Taolo.

Last month, in excess of 20 dead elephants were found in Zimbabwe, between Hwange national park and Victoria Falls, with some fearing that the cause of death may be linked.

The bodies were found, tusks intact, near water sources.

McCann again:

One leading theory is that it was caused by a strain of a bacteria called pasteurella, which killed 200,000 Saiga antelope in Kazakhstan in 2015, says McCann. “There are various options. Thankfully the UK government has collaborated with the government of Zimbabwe to export these samples and now they’re going to be tested in the UK,” he said.

If it is something relatively common scientists should be able to detect it. “However, new emerging infectious diseases are happening all the time and the more we look into epidemiology the more we discover we don’t know. So it could be a complete mystery again,” said McCann.

So, as one mystery looks to be solved, another may have presented itself.

In amongst all of that, we shouldn’t lose sight of the fact that its humans who present the greatest threat of all to the survival of one of the world’s most noble creatures.

[sources:guardian&cbc]