Past Research: Saving Arapaimas and Wetlands

South America’s largest freshwater fish, the arapaima (AIR-uh-PYE-muh), is in danger of disappearing before we know enough about it to save it. But Shedd scientist Dr. Lesley de Souza worked to change that.

Her fieldwork in the remote Rupununi wetlands of Guyana, in South America, was a first-of-its-kind study of the migratory patterns of arapaimas. By learning where these fish live, both in the dry season and in the rainy season, and when they move into flooded grasslands and forests, she could contribute to a conservation management plan to protect their feeding and breeding habitats.

Giant fish in big trouble
Arapaimas can grow to 10 feet and 400 pounds, although most are about half that size. This top predator is vital to the health and balance of its floodplain ecosystem and to the livelihoods of the people who reside there, too. The arapaima is an important food species that has been overhunted, and populations have dropped so drastically that the fish is endangered in much of its range.

Team effort
Lesley’s studies were in and around the Rewa River, which has the largest arapaima population in Guyana. With techniques learned from Shedd’s veterinarians and expert support from local Amerindian research partners, she safely implanted tiny radio transmitters in the giant fish. Then she and her crew tracked their movements through radiotelemetry — and through deep water and mud.

Her research team also included biology students from the University of Guyana. By providing them with this rare field experience, she helped train the people who will protect and manage Guyana’s wildlands. The president of Guyana has even visited her field station to learn about this important project firsthand.

No time to lose
In three field seasons, Dr. Lesley tagged more than 20 arapaimas and made important discoveries about the fish’s movements and territories that will help shape a protected area.

Dr. Lesley’s research had a sense of urgency: The Rupununi region is vulnerable to development, oil drilling, logging, mining and clearing for agriculture. The complex network of seasonal ponds, meandering creeks and shallow lakes that dot and cross vast grasslands and forests are home to a rich diversity of wildlife — some only found there. And Amerindian communities are intimately connected to the wetlands for food, materials for their homes, canoes and crafts, and traditional medicines. Protecting the arapaimas’ habitat, which expands with the river during the annual floods, will also protect Rupununi’s freshwater and terrestrial habitats, preserving a unique ecosystem and culture.



About the team

Learn more about Dr. de Souza and the conservation research team.


See Lesley's recent work in the New York Times science blog!

You can help!

Join Dr. Lesley’s team in Rupununi—through a donation to Shedd’s annual fund. Your support will help make sure she has the equipment and supplies to continue her work to preserve and protect these magnificent fish and their habitats.

And be sure to visit Shedd’s Amazon Rising exhibit to see amazing arapaimas, with their glittering gold and red scales, for yourself!

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