Cyanobacteria May Be Behind The Mysterious Elephant Deaths In Botswana, Says Govt

In May-June, hundreds of elephants were said to have mysteriously died in Botswana. The reason was unknown then but today scientists claim they finally know what killed over 350 elephants in the country's Okavango Delta wetlands.

The reason seems to be neurotoxins spread by thriving colonies of bacteria living in the region's water holes.

Mail Online

"Our latest tests have detected cyanobacterial neurotoxins to be the cause of deaths. "However, we have many questions still to be answered, such as why the elephants only and why that area only,¡± Mmadi Reuben, principal veterinary officer at the Botswana department of wildlife and national parks, reportedly said during a news conference on Monday.

Over 70 per cent of these elephants were found near water sources polluted with large amounts of cyanobacteria.

According to Live Science, it is ¡®a single-cell organism also known as blue-green algae, named for their tendency to clump together in large green mats or "blooms" on aquatic surfaces. These blooms can be hazardous or even deadly, harbouring toxins that attack the nervous system, skin or liver of animals exposed to them¡¯. Cyanobacteria blooms have previously been known to cause mass die-offs of fish, birds and other animals, according to a 2008 study in the journal Global Change Biology.

Also Read: A New Pathogen May Be The Cause Of Mysterious Deaths Of Elephants In Botswana

Guardian

Cyanobacteria use photosynthesis to make food from sunlight which means they often thrive during summer heat waves, according to the 2008 study. As global climate change increases the frequency and severity of heat waves (2020 was hottest summer ever recorded in the Northern Hemisphere), algal blooms are becoming more widespread, and so have their toxins.

According to Reuben, the Botswana government's investigation revealed "a combination of neurotoxins" in the watering holes near the dead elephants. No other species seem to have fallen victim to these toxins (except for one horse). The possible reason for that could be that the elephants are particularly susceptible because they spend a lot of time bathing in the holes and drinking large quantities of water from them, according to Live Science.

Elephants Without Borders

Reuben said that tissue samples taken from the affected elephants are still being analyzed by lab partners in the United States, U.K. and South Africa.

Talking to The Guardian Niall McCann, director of conservation at U.K.-based charity National Park Rescue said that officials should refrain from drawing any conclusions until those results are in.

"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,¡± he reportedly said.

The results are still awaited.

Also Read: Naturally Occurring Toxin Could Have Killed The 300 Elephants In Botswana, Says Probe