Entrapped Bolivian River Dolphins
With the support of the Wild Animal Health Fund, two zoo and wildlife veterinarians were called to assist in a major conservation situation in the Santa Cruz region of Bolivia. Landscapes in this area are rapidly changing due to farming and forest fires. Rivers tend to erode bringing silt to the rivers, carrying pesticides, heavy metals, and diseases from domestic animals. With those factors, river courses begin to change and form bends and then lakes. In the fall of 2018, a newly formed lake had separated from a main river and entrapped 14 Bolivian river dolphins.
The Bolivian River dolphin is one freshwater dolphin species affected by external factors. They are native to South America and are pink and gray in color. They are the largest freshwater dolphin in the world. Bolivian river dolphins are elusive and small in numbers, which makes conservation and research even more important.
We don’t know much about these animals. This species is categorized as Vulnerable by the Bolivian government and listed in the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITIES). Due to habitat loss, population declines and the lack of basic information on the species led to conservation initiatives to protect the Bolivian River Dolphin.
In 2010, rescues were performed on isolated river dolphins in the area of Rio Grande, where 38 dolphins were translocated. For a few more years, rescues of dozens of animals have been translocated. Unfortunately, no data regarding the outcomes of these translocations since post-movement monitoring was not in place.
Helping entrapped Bolivian river dolphins
By 2018, the Bolivian government and associated biologists knew the problem of entrapment of river dolphins continued to be an ongoing problem. Also, due to the lack of any health data for the species or a project veterinarian, a request for two well-known veterinarians from Maryland Zoo and St Louis Zoo, were asked to help with translocations. Both these doctors were asked due to their 17+ years of working collaboratively on wildlife health projects in Bolivia.
Without information on the species health, data on infectious diseases, and contaminants, hinders conservation efforts of river dolphins and the humans and animals that live in and around the rivers. Therefore, veterinarians assisting in the rescues to investigate the health status of this endemic dolphin was imperative. In addition, there was a great need to establish translocation protocols for implementation for the Bolivia River Dolphin future rescues.
In late 2018, the veterinarians traveled to Bolivia and lend expert veterinary support to the successful translocation of six river dolphin. Health examinations were performed before, during, and after their translocations back to the home river. A multitude of samples of blood, fecal and tissues were collected from the animals to analyze for exposure to infectious diseases and toxins.
What the veterinarians had hypothesized originally was that the trapped dolphins would be in poor health. However, they found that the initial 6 rescued dolphins were in good body condition from the health parameters evaluated.
Overcoming adversity
Plans to return for the second translocation were disrupted by the wide-spread Amazonian wildfires throughout most of 2019 and into 2020. Plus, there was the coup in 2019 prevented traveling to the country unsafe for many months. As we all know too well, the COVID-19 pandemic caused a travel ban for the next two years. Thankfully, the Wild Animal Health Fund continued to approve extensions of the funding dates to complete the project. The Bolivian government and scientific colleagues continued to monitor the remaining trapped dolphins during this time.
In the return trip in 2022, they veterinarians found that the remaining six dolphins were thinner and all had toxins of infectious diseases, probably due to the length of time spent in an enclosed lake. After translocating these dolphins, a sampling of the dolphins were GOS tagged to monitor post-release movements.
A bright future for Bolivian river dolphins
Human-caused changes to the environment to produce food are causing the Bolivian dolphin to become trapped. In addition, Human-caused global issues challenged the speedy assistance of veterinary support to help the conservation concern. Work continues with Bolivian colleagues to broaden the scope from rescuing trapped dolphins to forming working relationships with landowners and the government to prevent future entrapments.
The resources provided by the Wild Animal Health Fund were invaluable to be the first health study of this rarely studied species.
It’s crucial for veterinarians to play a part in saving species. Without data from the above study, change won’t happen. As you have read, conservation can’t go far without knowledge of underlying issues and animal health.