In parallel with the extreme heat and drought, the number of dolphins dying is increasing in the Brazilian Amazon. Authorities stated two more dolphins were found dead in Tefe Lake, and the number of dolphin carcasses found between September 24 and October 2 reached 110. Experts state that the deaths may get more frequent if the water temperatures continue to rise.
Oceanographer Miriam Marmontel stated that the water temperature in Tefe Lake rose 8 degrees above normal and said that warming could play a decisive role in deaths because it could cause hyperthermia. On the other hand, Marmontel also stated that high temperatures increase a toxic substance in the water and said that weakened dolphins cannot swim to the river feeding the lake to survive.