Tracking of Giant Freshwater Stingray after a Year of Release into Mekong River

Boramy, the World’s Largest Freshwater Fish, have been being tracked after one year of release into the Cambodian Mekong River. The Wonders of the Mekong research project, funded by the U.S. Agency for International Development (USAID), uncovered clues that will help save the endangered megafish and the river where it lives, said a news release, adding that last year’s discovery of a 661-pound giant freshwater stingray launched a new initiative by the U.S. government to study and protect one of the largest, most mysterious creatures on the planet.

According to the news release of the Wonders of the Mekong project, the scientists dubbed the stingray “Boramy”, which means full-moon in Khmer. Over the last twelve months, in collaboration with the Fisheries Administration, scientists have been tracking the record-breaking stingray. After its capture in June 2022, Boramy was fitted with an acoustic tag before being released back into the river. The data gathered revealed that despite its enormous size, the female giant has a remarkably small home range, centered in a bio-rich but threatened stretch of the Mekong River in northern Cambodia.

Scientists know very little about the giant freshwater stingray, a species whose population has dramatically declined across its Southeast Asian region. This month, the USAID-funded studies will publish valuable findings. “The Mekong River, which runs through six Asian countries, is a global biodiversity hotspot and home to almost 1,000 different species of fish, including the world’s largest freshwater stingray,” says Kerry Pelzman, USAID/Cambodia Mission Director. “USAID is proud to join efforts to safeguard the wonders of the Mekong and to protect endangered species to help sustain Cambodia’s rich fisheries and livelihoods for millions of Cambodians.”

“This new information about the stingray and other critically endangered fish is crucial to the protection of Cambodia’s most iconic animals and the preservation of a river that provides food and livelihoods for millions of people,” says Zeb Hogan, a biology professor at the University of Nevada, Reno, who leads the USAID-funded Wonders of the Mekong research project that initiated the study. “The giant stingray is now at the centre of a larger debate about the fate of the Mekong, and how to balance river basin development with environmental stewardship so that the bountiful Mekong can continue to provide for people in the region for generations to come.”

Globally, the International Union for Conservation of Nature has assessed the giant stingray as endangered due to population declines as high as 79 percent over the last century.

Freshwater fish are defined as those that have spent their entire lives in freshwater, as opposed to giant marine species like bluefin tuna and marlin, or fish that migrate between fresh and saltwater like the huge beluga sturgeon.

Source: Agence Kampuchea Presse