A study undertaken in Brazil has detected genetic alterations in the Amazon river dolphin (Inia geoffrensis), an endangered aquatic mammal found only in the Amazon and Orinoco river basins of South America. Scientists from the National Institute for Amazonian Research and the Foundation to Support Research in the State of Amazonas have still not determined if the modifications in the dolphin genome are the result of pollution.

But they did detect mercury and the pesticide dichlorodiphenyltrichloroethane (DDT) in the blood and tissue samples from the 27 specimens tested.

The Amazon river dolphin "is at the top of the food chain, which causes toxic substances to accumulate in its organism. Now we are going to study the impacts this could cause," biologist Eliana Feldberg, a participant in the research, told Tierramérica.

"In addition, it is an animal that shares genetic information with its ancestors, and understanding how its genome functions helps us understand its evolution," she said.