This newly discovered river dolphin species is already threatened with extinction

Scientists have found a new species of river dolphin that's been living in Brazil's Araguaia River — the first such discovery in nearly 100 years — and their research may settle some long-standing arguments about other dolphin species as well.

This new species, named Inia araguaiaensis or simply the Araguaia river dolphin, was discovered after a team of Brazilian and UK scientists collected DNA samples from various dolphins living in the Amazon and Araguaia river basins. Since these two river basins have been mostly isolated from one another for the past two million years or so, the researchers were interested in seeing how this separation changed the species that inhabit them. By analyzing the DNA samples, and examining physical differences (such as size of braincase and number of teeth), the researchers found that although the dolphins living in the Araguaia River look very much like the two other known species (Amazon and Bolivian), there are enough differences between them to set them apart as a brand new species.

This is now one of only five known species of river dolphin in the world

"It was something that was very unexpected," Dr. Tomas Hrbek, the lead author of the study from the Federal University of Amazonas, told BBC News. "It is an area where people see them all the time, they are a large mammal, the thing is nobody really looked. It is very exciting."

Although discovering new species is always amazing and exciting, this particular news is tainted by the realization that even though we've only just found them, the Araguaia river dolphin is in danger of going extinct.

Based on how many they saw during their study, the researchers estimate there could be less than 1,000 of these dolphins left, and they are recommending that they be given 'vulnerable' status on the IUCN's Red List.The main threat to them is, as expected, human activity. The ecology of the Araguaia River basin has suffered over the past 50 years or so due to farming, ranching and damming of the river, but as Dr. Hebrk told BBC News, people are having a more direct impact on their population.

"The dolphins are at the top of the line, they eat a lot of fish," he said. "They rob fishing nets so the fishermen tend to not like them, people shoot them."

Their research may also settle what seems to be a long-standing disagreement in the scientific community about whether or not the Amazon and Bolivian river dolphins are also two distinct species. Many science journals refer to the Bolivian river dolphin as a subspecies of the Amazon river dolphin, however the DNA analysis by Dr. Hrbek and his team provides evidence that they actually are distinct from one another.

(Photos courtesy: Nicole Dutra/Federal University of Amazonas)

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