Pink Dolphins Are Dying. Scientists Launch Mission

Amazon Rainforest (Inia geoffrensis) are unique freshwater mammals found only in the rivers of South America. They are one of the few species of freshwater dolphins left in the world. Due to their slow reproductive cycles, their populations are particularly vulnerable.

Last year, between 200 and 300 dead individuals were found in Lake Tefe in the western Brazilian state of Amazonas when the area was hit by a severe drought. It is a 45-kilometer-wide body of water near the Solimoes River, which the animals are particularly fond of.

During the drought, when the river level dropped significantly, the water temperature reached too high for dolphins to survive in. In September, at a depth of three meters, it was 39 degrees Celsius, more than 10 degrees higher than the average for this time of year. Due to the lack of oxygen in the water, thousands of fish died in Amazonian rivers.

Scientists want to better understand the impact of climate change, including drought and rising temperatures, on this species of dolphin. This week, a female dolphin was captured from Lake Tefe for a range of studies. A microchip was also implanted in the dolphin’s skin, allowing it to track its behavior and movements, as well as remotely check the water temperature and depth. Once the scientists had finished their work, the animal was released back into the lake.

– We need to know more about the populations of this species, said Miriam Marmontel of Brazil's Mamiraua Institute of Natural Sciences.

Amazon dolphins grow to a length of 270 centimeters and weigh up to 135 kilograms. Due to their characteristic color, they are called pink dolphins.

See also: A pink dolphin is stuck on the river bank.