the wwf hopes to build a database of dolphin health throughout all of amazonia. most of the animals here are relatively small and lean -- none weighs over 70 kilos. breathing and heart rate are constantly monitored. this examination runs more smoothly. inside half an hour the tests are complete, and a gps transmitter is attached to the dolphin's dorsal fin, which consists almost entirely of cartilage. miriam: the animals do feel what we're doing to them. but for the invasive interventions, the biopsies and attaching the transmitter, they're given a local anesthetic. reporter: the dolphin will be released back into the open water as quickly as possible. the wwf hopes the project will help to get the pink river dolphin onto its list of threatened species, to better protect them and their biosphere. back in the water, the erstwhile captive's buddies are there to welcome it home. host: and that's all for today. but we love hearing from you, so do write to us at global3000@dw.com, or on facebook. bye for now. see you soon. ♪ [captioning performed by the national capti