Drought, Triple-Digit Water Temperatures Killed More than 100 Dolphins Last Week

Scientists say more than 100 dolphins have been discovered dead over the past week in the Brazilian Amazon, as the rainforest has weathered a historic drought and record-high water temperatures above 102 degrees Fahrenheit.

The mammals were all found in Lake Tefé, the Mamirauá Institute, a research facility funded by the Brazilian Ministry of Science, told CNN, adding that the high number of deaths is considered unusual.

“It’s still early to determine the cause of this extreme event but according to our experts, it is certainly connected to the drought period and high temperatures in Lake Tefé, in which some points are exceeding 39 degrees Celsius (102 degrees Fahrenheit),” the institute told the news network.

The Amazon River is now in its dry season, CNN reported. Several river fauna specimens have also suffered from the record-high water temperatures.

Activists and researchers are now working to transfer surviving dolphins from lagoons and ponds to the river's main body of water, where temperatures are cooler, the outlet reported.

Given the remote location, however, the rescue operation is challenging.

“Transferring river dolphins to other rivers is not that safe because it’s important to verify if toxins or viruses are present [before releasing the animals into the wild],” André Coelho, a researcher at the Mamiraua Institute, told CNN Brasil.

According to the network, 59 municipalities in the Amazonas State have reported below average water levels, impacting fishing and transportation on the river.

More acute droughts are expected in coming weeks, which can trigger more dolphin deaths, CNN reported.

In August, scientists monitoring Florida's coral reefs said an abnormally hot year was responsible for killing off more of the ecosystem, which also contributed to the loss of marine life such as stone crabs and lobster.