After being trapped in a lake with no escape, six Bolivian river dolphins were rescued thanks to veterinarians from the Maryland and Saint Louis Zoos.
The dolphins were isolated in a lake in central Bolivia and had been cut off from the main river over the past several years because of run-off from environmental changes in the area.
“This species is endemic to Bolivia,” said Dr. Ellen Bronson, senior director of animal health, conservation, and research at The Maryland Zoo. “They face many threats in the wild mostly due to the conversion of forest into soybean fields, which leads to erosion of dirt into rivers, along with potential contaminants and diseases. They are very secretive, and little is known about their biology and health, including how these environmental changes affect their survival.”
The rescue mission was funded from a grant from the American Association of Zoo Veterinarians’ Wild Animal Health Fund so the vets were able to buy medical supplies and custom-built fishing nets made by Bolivian women.
The team traveled to the remote location about 150 miles from Santa Cruz and guided the dolphins into transfer nets. After an examination, the dolphins were put into a pick-up truck and released into the main river. Transporting a dolphin from the lake to the river took about two hours and the dolphins were monitored closely the entire time.
“We believe that these were the first full health examinations done on this species with extensive diagnostic sampling. There have been research studies on this species in other areas of Bolivia, and they have also taken some limited samples, but not to this extent,” said Bronson.
There are still nine dolphins that are trapped in the lake and plans for the next rescue mission are currently underway.
“This dolphin rescue and translocation project is an example of the positive impact that zoos and aquariums accredited by the Association of Zoos and Aquariums (AZA) can have by working to ensure the health and conservation of endangered species, whether the species are living in world-class AZA zoos and aquariums or are in the wild living in habitats that are rapidly being modified by the growing human footprint,” said Dr. Sharon Deem, director of the Saint Louis Zoo Institute for Conservation Medicine. "We hope to continue our collaboration in the near future on behalf of the river dolphins in Bolivia."