Transcript for Scientists use satellite tags to monitor Amazon River's living legend, pink dolphins
Reporter: They're the world's most intelligent animals, second only to humans. Dolphins are majestic and playful. But there's one rare subspecies that remains a mystery to scientists. The pink dolphin of the Amazon river is a living legend. And we're about to catch our first glimpse. Right now they've got one dolphin. You can see it right there behind me. It's totally surrounded. The world wildlife fund is on a mission to tag 15 dolphins throughout Brazil, Colombia, and here in Bolivia, to study their health and behavior. The group consists of local fishermen and scientists. Scientists fear the pink river dolphin is vulnerable to exdistinction due mostly to manmade threats like mining, hunting, and deforestation. Waiting for them under tents is a makeshift O.R. They're bringing the dolphin out of the boat. Very quick process, they move fast. Pink dolphins can only be out of the water for up to 50 minutes. With the clock ticking, veterinarian Karla Sanchez and her team hydrate the dolphin to lower its stress. As they conduct a physical, the researchers numb its tail. Then take tissue and blood samples to test for Mercury, toxic substances, and general health. Sign tests don't know for sure how these freshwater dolphins get their pink color. Hypotheses include diet, water quality, and sunlight exposure. But they do know they get pinker as they age. A pink dolphin, why aren't they more well known? We didn't communicate about these dolphins. They are very attractive, more cute, in my opinion, than the marine dolphins. Reporter: As quickly as it came out, the dolphin is returned to the water. Pink dolphins are known as an indicator species. Highlighting the overall health of the Amazon. If they're doing well, so is the river. But deforestation has been changing the water. All the deforestation is having an impact, because the less trees that means there's more runoff. And more runoff means there's more sediment getting into the rivers. Reporter: Sediment can prevent the dolphins from swimming freely, as it did in 2010 when these trapped dolphins had to be rescued. It's just after 4:00 A.M. We're about to drive two hours into camp, then head right out into the Amazon. With one more dolphin to tag, we embark on a nearly three-hour journey through punishing terrain. The road is mud and water. Freeding the tracking charge is Paul van dam, biologist and director of a Bolivian Ngo, bon agua. We want to know how far they travel in the river, searching for females, searching for family, searching for food. This is what we actually want to investigate. Reporter: And just minutes after boarding our canoes -- a downpour. We are setting out in the rain. So we're a bit unlucky. But rain does not interfere in the capture of the dolphin. Reporter: The ride out is bumpy. After an hour, the fishermen find a lookout point for the elusive dolphin. We're now setting up our camp. So the fishermen are preparing the setup to put the next -- to nets to capture the dolphins. Reporter: Finally it's go time. The team starts by checking its vitals. Right now they have to work as quickly as possible, and they also want to make sure to keep it very calm. That's why I'm talking very slowly right now. With the examination complete, the tagging begins. Each tag will ping data back to a satellite once a day. This drill, commonly found in your tool box, becomes vital to tracking these mammals. First thing they had to do was disinfect the whole area. Then give it an anesthetic. And one guy right here, all he's doing is holding the snout shut. Because the dorsal fin is made of collagen, the dolphin's pain will be minimal. We're inserting it right now. It's like a mixture of blubber and metal. And within moments, the tracker is attached. Now there's a rush to get it right back into the water. And she's set free. For people in the United States, what do you hope they learn? It's important that you have to be -- the conservation of this type of species is something global. It's not something local. I think we need support from the global community to conserve this species. Reporter: Now they wait in hopes this data will shed light on how to protect this mysterious and beautiful animal. For "Nightline," I'm Victor Oquendo in baya vista, Bolivia. Touch is how we communicate
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