Botswana government says toxic algae bloom caused mass elephant deaths

Botswana's government determined that a toxic algae bloom is responsible for the deaths of more than 350 elephants earlier this year. Photo by Gernot Hensel/EPA-EFE

Sept. 22 (UPI) -- Botswana's government determined that toxic algae was responsible for the deaths of more than 350 elephants in the African country earlier this year.

Cyril Taolo, acting director of Botswana Wildlife and National Parks, said Monday that the elephants in the Seronga area in southern Africa died from a neurological disorder after drinking water tainted by a toxic algae bloom.

Taolo added, however, that no other species seemed to be affected by the contaminated water and that scavengers such as hyenas and vultures who were seen feeding on the carcasses of the affected elephants did not show signs of illness.

Laboratory analysis of the elephant carcasses found that the likely cause of death was a cyanobacteria that can cause paralysis and respiratory failure.

Local reports found that about 70% of elephants died near water holes that contained algal blooms.

Niall McCann of British charity National Park Rescue, who discovered 169 dead elephants during a 3-hour flight over the Okavango Delta in early May, said the government's determination "rules out some of the more sinister things" including human intervention such as poaching.

He also said the work to determine exactly what caused the deaths was not quite done.

"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," McCann said.

McCann further warned that natural elephant die-offs will be exacerbated by climate change with increasing temperatures acting as a "threat amplifier."