Six critically endangered Mekong giant catfish, one of the largest and rarest freshwater fish in the world, were captured and released in Cambodia recently, rekindling hopes for the survival of the ‘species.
The underwater giants can grow up to 10 feet long and weigh up to 660 pounds, or as heavy as a grand piano. They are now found only in the Mekong River in Southeast Asia, but they once inhabited the entire length of this 3,044-mile river, from its mouth in Vietnam to its northern reaches in China’s Yunnan province. .
The species’ population has fallen by 80% in recent decades due to increasing pressures from overfishing, dams that block the migratory path the fish follow to spawn, and other disturbances. According to the World Wide Fund for Nature, some experts estimate that there may be only a few hundred of the Mekong giant catfish left.
Chhut Chheana/USAID Document on the wonders of the Mekong via REUTERS
Among the millions of people who depend on the Mekong for their livelihood, few have ever seen a giant catfish. Finding six of the giants, who were captured and released within 5 days, is unprecedented.
The first two were on the Tonlé Sap River, a tributary of the Mekong not far from the Cambodian capital Phnom Penh. They were given identification tags and released. On Tuesday, anglers caught four more giant catfish, including two measuring over 6.5 feet and weighing 264 pounds and 288 pounds, respectively. The captured fish were apparently migrating from their floodplain habitats near Tonle Sap Lake in Cambodia northward along the Mekong River, probably to spawning grounds in northern Cambodia, Laos, or Thailand.
“This is an encouraging sign that the species is not at imminent risk of extinction, as in the coming years, giving time for conservation activities to be implemented and continue to drive the curve of the decline toward recovery,” said Dr. Zeb Hogan, a research biologist at the University of Nevada, Reno, who leads the Wonders of the Mekong project, funded by the U.S. Agency for International Development.
Much is still unknown about this giant fish, but over the past two decades a joint conservation program by Wonders of the Mekong and the Cambodian Fisheries Administration has captured, tagged and released around 100 of them, allowing thus to better understand how catfish migrate, where they live and the health of the species.
“This information is used to establish migration corridors and protect habitats to try to help these fish survive in the future,” Hogan said.
Zeb Hogan, USAID Wonders of the Mekong Project via AP
The giant Mekong catfish is an integral part of the region’s cultural fabric, depicted in 3,000-year-old cave paintings, revered in folklore and considered a symbol of the river, whose fisheries feed millions and are valued at $10 billion per year.
Local communities play a crucial role in conservation. Fishermen now know the importance of reporting incidental catches of rare and endangered species to authorities, allowing researchers to reach the locations where fish were caught, measure and tag them before releasing them.
“Their cooperation is essential for our research and conservation efforts,” Heng Kong, director of the Cambodian Inland Fisheries Research and Development Institute, said in a statement.
Besides the giant Mekong catfish, the river is also home to other large fish, including salmon carp, thought to be extinct until spotted earlier this year, and the giant stingray.
The fact that four of these fish were caught and tagged in a single day is likely “the big fish story of the century for the Mekong,” said Brian Eyler, director of the Southeast Asia program at the Stimson Center, based in Washington. He said seeing them confirms that the annual fish migration was still robust despite all the pressures facing the environment along the Mekong.
“I hope what happened this week will show Mekong countries and the world that the Mekong’s powerful fish population is unique and must be conserved,” he said.
Threats to endangered aquatic species
In addition to overfishing and plastic pollution, the Mekong Basin has been degraded by upstream dams and climate change, which have had a major impact on water levels in the aquatic habitat of the endangered catfish extinction criticism.
According to WWF, threats to the Mekong giant catfish include infrastructure development such as dams that block migration routes.
“Without the ability to move up and down rivers, fish have fewer opportunities to reproduce,” explains WWF.
Zeb Hogan/USAID Document on the wonders of the Mekong via REUTERS
Cambodia has imposed strict restrictions on fishing in the vast river to try to reduce the number of endangered aquatic species killed in nets.
The number of Irrawaddy dolphins, which once swam across much of the mighty Mekong, has declined despite efforts to preserve them.
In 2022, Cambodian fishermen got a shock when they inadvertently hooked a giant freshwater stingray, an endangered species, four meters long and weighing 180 kilos.
Over the past 25 years, CFA and researchers have tagged and released around 100 giant catfish as part of a conservation program that encourages fishermen to report their catches of rare species.
Conservationists said recent captures of giant catfish mark “a new era of conservation” and “new hope for the survival of a species that has become increasingly rare in much of its habitat natural”.
Agence France-Presse contributed to this report.
