Decoding the Mystery of the Pink Dolphin

To protect the pink river dolphin, the largest freshwater dolphin species in the world, scientists are working to decode the mysteries of their lives and habitats in the face of climate change and human impacts.

Fishermen who once caught the rare pink river dolphins (also known as Boto or Amazon river dolphins) are collaborating with researchers in the Amazon rainforest of Bolivia in a high-tech effort to ensure the survival of this species and better understand their needs.

Satellite technology enables fishermen and scientists to monitor the journey and living habits of pink river dolphins.

Scientists from the global environmental group WWF and the Bolivian NGO Faunagua recently tagged four freshwater dolphins in the Ichilo River using satellite technology, allowing fishermen to use a mobile app to report their locations.

Paul Van Damme from Faunagua stated: “They (the fishermen) have hunted dolphins for various purposes. Now, we are raising their awareness and turning them into our partners in research on this pink river dolphin species.”

Information about the habits, diet, and migration of pink dolphins will be used to protect this species.

According to WWF, despite the iconic status of the river dolphin, very little information exists about their population and habitat. Fishermen who frequently navigate the river will provide scientists with insights into what dolphins eat, how far they migrate, and clues about the threats they face.

Lila Sainz, head of WWF Bolivia, noted that they have given fishermen a new perspective on a species that has been their target for hunting for many years.

Sainz said: “Everything that affects the dolphins will also affect humans—who also rely on those resources. Therefore, if dolphins thrive, it shows that the human habitat is also doing well.”

The pink river dolphin (Boto, Amazon river dolphin) is the largest and rarest freshwater dolphin species in the world.

The vast Amazon rainforest of Bolivia is a crucial habitat for many species, from dolphins to birds and jaguars, all of which are threatened by deforestation, dam construction, wildfires, and development.

Why are Amazon river dolphins pink?

Amazon river dolphins have distinctive skin and appearance compared to other dolphin species. The exact reason for this is not fully understood, but it is believed to be a combination of genetic, dietary, and environmental factors.

One reason explaining the pink coloration in this dolphin species is due to their diet being rich in carotenoids—organic pigments found in the fish and crustaceans they consume. Carotenoids are known to contribute to the pink or orange coloration of some bird species (like flamingos), fish, and reptiles, so it is possible that a similar mechanism is responsible for the pink coloration in dolphins.

“This freshwater dolphin species is the largest river dolphin still existing on the planet. They are born gray, and over time, the pink will gradually appear as they mature. Their final coloration will be influenced by many factors, including behavior, diet, and the proximity of capillaries to the skin,” explained biologist and author Helen Pilcher.

Additionally, a combination of genetic and environmental factors may also play a role. Some studies suggest that the pink color may relate to the thickness of the skin, which could affect the blood flow through the skin. Hormones, stress, or other factors might also influence the coloration of the Amazon river dolphin.