Brasilia: A new study has revealed that extreme heat and drought have transformed an Amazon lake into a dangerously hot body of water, resulting in the deaths of hundreds of dolphins and highlighting the severe impact of climate change on tropical ecosystems. Researchers led by hydrologist Ayan Fleischmann from Brazil's Mamiraua Institute for Sustainable Development reported that in September 2023, water temperatures in Lake Tefe soared to 105.8 °F (41 °C), exceeding the heat of most spa baths.

According to Anadolu Agency, Fleischmann expressed the psychological toll of witnessing the carcasses of pink dolphins and tucuxis, both of which are endangered species. The findings, published in Science and reported by CBS News, indicate that five out of ten Amazon lakes studied experienced unprecedented daytime temperatures above 37 °C, with Lake Tefe's surface area decreasing by 75%.

The study's modeling suggested that strong solar radiation, shallow depths, and weak winds combined to trap heat in the lake's stagnant waters. The World Wildlife Fund (WWF) Brazil reported that 153 dolphins were found dead within a single week in September 2023. Fleischmann emphasized the urgent need for long-term lake monitoring and the importance of involving Indigenous and riverine communities in climate adaptation efforts.

This research coincides with the opening of the UN COP30 climate summit in Brazil, drawing attention to the immediate consequences of warming waters on the Amazon's fragile ecosystem. David Hannah from the University of Birmingham, a co-author of a related study, warned of the significant and often detrimental implications rising river water temperatures can have on aquatic life.