Hundreds of elephants mysteriously died between May and June in Botswana from apparently no cause, baffling experts worldwide. Now the government says it has unsolved the mystery.
The out-of-the-blue death spree baffled experts and conservationists earlier this year, and the leading hypothesis blamed a rodent virus known as EMC (encephalomyocarditis) or toxins from algal blooms caused the deaths.
Botswana government at that time said there could be two possible causes for the deaths, one, a toxin outbreak, and two, an unknown parasite attack.
Now, as per their updated report, the hundreds of elephants died from ingesting toxins produced by cyanobacteria, the government said on Monday, adding more questions are yet to be answered.
“Our latest tests have detected cyanobacterial neurotoxins to be the cause of deaths,” a principal veterinary officer at the Botswana department of wildlife and national parks, Mmadi Reuben told media in a news conference.
Cyanobacterial neurotoxins, as the term suggests is a toxin produced by cyanobacteria, one of the oldest living microorganisms on earth. These bacterias, a.k.a blue-green algae (not all cyanobacteria produce toxins) are found in lakes and other water bodies.
In an environment with a high concentration of phosphorus, these bacterias ‘bloom’ exponentially and while blooming they produce the highly toxic substance called the cyanotoxins, which is lethal enough to kill animals and humans at certain marks.
Botswana government says they have traced the same toxin in the water potholes near which the elephants were found dead earlier this year. But how these toxins came into being, and why only elephants died still remains a question.
“We have a number of hypotheses we are investigating,” said Mmadi Reuben.
Initially, the toxic outbreak theory was dismissed by scientists as a cause of deaths for the elephants, since no other species died, except for one horse.
But now scientists think elephants could be particularly susceptible to die from this highly toxic algae because they spend a lot of time drinking and bathing these waters.
Despite the Botswana government’s claim of unraveling the mystery, and ruling out one over the other ‘more sinister causes’ for such deaths, experts are skeptical.
The principal veterinary officer declined to comment where the tests were made that said the cause of deaths were a ‘combination of neurotoxins.’
Head of a UK-based charity National Park Rescue, Dr. Niall McCann ruled out the possibility of cyanobacterial as a principal cause of the mass die-off.
He said: “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 told The Guardian.
Samples from the dead elephants in Botswana will be tested in the UK as well, for a wider probe on the matter, which has raised a lot of concern among conservation activists.
Botswana government says they’ll be monitoring the water bodies or waterholes for the algae blooms so that such fate could be averted next year.
Botswana is home to 130,000 African elephants – more than any other African country. Last year a ban on elephant hunting, effective from 2014 was scrapped sparking an international outcry.