At least 330 elephants died at once in Botswana earlier this year, and now scientists are figuring out why that is.
Scientists believe the elephant deaths may have been due to toxic algae blooms, ABC News reported. The algae is known as cyanobacteria. It is a naturally occurring neurotoxin that is particularly harmful to elephants.
The blue-green algae bloom in situations where the water is warm, stagnant and full of phosphorus and nitrogen, according to the Centers for Disease Control. Some common sources of phosphorus and nitrogen are fertilizer runoff or septic tank overflows.
Was This Caused by Climate Change?
A number of scientists consider this the latest example of environmental hazards caused by climate change. They believe the cyanobacteria are more plentiful due to a warming climate.
“As in so many other situations, such as the wildfires in California and Oregon and the floods in the U.K., climate change is the threat multiplier,” Dr Niall McCann, co-founder of U.K.-based charity National Park Rescue, told ABC News. “Climate change and the effect of global warming on the region is increasing both the intensity and severity of harmful algal blooms, making this issue more likely to reoccur.”
Veterinary officers in Botswana conducted tests and found traces of the cyanobacteria in seasonal water pans where the elephants drank. Most of the dead elephants had gathered around waters close to the Okavango Delta, a popular tourist safari spot. When those waters dried up, the elephant deaths stopped.
For some reason, other animal species remain unaffected by the cyanobacteria. Scientists have a theory: elephants drink with their trunks from deeper levels of the watering holes. So they’re siphoning up water from closer to the silt, where the cyanobacteria pools.
Botswana plays host to the world’s largest elephant population. Its roughly 130,000 elephants comprise about a third of Africa’s total elephant inhabitants.