Climate change led to mass poisoning of hundreds of elephants

Algae blooms and their causes

Cyanobacteria are a common group of blue-green algae. There are thousands of different species that spend most of their lives photosynthesizing and releasing oxygen.

But under certain conditions, algae can release toxic compounds known as cyanotoxins that are lethal to a wide range of animals. But as our algae expert Doctor Anne Jungblut Why cyanobacteria produce these is not well known, he explains.

“Cyanotoxins are energetically costly, so there has to be a good reason to produce them,” he explains. “Otherwise these genes would be lost in the process of evolution.”

“However, we are not sure at this time what this cause is. Communication, defense or iron intake have been suggested but there is no clear consensus. Environmental triggers are equally elusive but may be linked to temperature or nutrients.”

While cyanobacteria were among the proposed causes of the mass elephant deaths in 2020, evidence linking microbes to the event was limited. Poaching, drought and infection by other bacteria were also suggested causes, but restrictions resulting from the COVID-19 pandemic meant investigation on the ground was limited.

This is where Davide comes into play. He was investigating how historic animal deaths could be linked to algal blooms as part of his PhD study, supervised by the Natural History Museum, Kings College London and the Plymouth Marine Laboratory. He believed that satellite observation could shed light on what was killing elephants.

“Algae blooms are routinely monitored by satellite, but this data is not often used to investigate mass mortality events,” he explains. “As the scale of elephant deaths from unknown causes is much higher than anything seen before, it is important to use all sources of evidence to investigate what is happening to elephants. These endangered animals.”