Droughts and heatwaves causing water in some areas to reach 41C, killing fish and endangered dolphins, say researchers
Amazonian lakes are being transformed into simmering basins hotter than spa baths as severe heatwaves and drought grip the region, research shows.
The temperature of one lake exceeded 40C (104F) as water levels plummeted under intense sunlight and cloudless skies. The extreme heat triggered mass die-offs among endangered Amazon river dolphins and fish, which cannot survive in such high temperatures.
The shallow waters of Lake Tefé, which were only two metres deep, reached 41C – warmer than an average spa bath. “We couldn’t even put our fingers in the water. It was really hot, not just in the top bit, but right down to the bottom,” said the lead researcher, Ayan Fleischmann, from the Mamirauá Institute for Sustainable Development. “You put your finger in and remove it instantaneously, it’s unbearable.”
Floating carcasses of up to 200 river dolphins washed up over a six-week period around September 2023. No one in the region had seen this happen over the past century, said Fleischmann. “It was completely surreal and really scary.”
