Six critically endangered Mekong giant catfish were caught and released recently in Cambodia, reviving hopes for the survival of the species.
The underwater giants can grow up to 10 feet long and weigh up to 661 pounds, or as heavy as a grand piano. They are currently found only within the Mekong River system, but previously inhabited the entirety of the 3,043-mile river from Vietnam to China’s Yunnan province.
The population of these fish has decreased by 80% over the last few decades due to overfishing, dam construction disrupting their migratory paths, and various environmental pressures. It is rare for anyone to spot one of these majestic fish, so catching six within just days is unprecedented.
The first two catfish were captured on the Tonle Sap River, near Cambodia’s capital, Phnom Penh. Those fish were tagged and released back to their habitat. Just days later, fishermen caught four more giant catfish, two of which measured over 6.5 feet and weighed between 264 pounds and 288 pounds. These catches indicate the fish were migrating up the Mekong River, likely returning to spawning grounds located in northern Cambodia or neighboring Thailand and Laos.
Dr. Zeb Hogan, a research biologist at the University of Nevada Reno and leader of the U.S. Agency for International Development-funded Wonders of the Mekong project, remarked, “It’s a hopeful sign... risk of extinction... which gives conservation activities time to be implemented and to continue to bend the curve away from decline and toward recovery.”
This new insight adds to the knowledge base being compiled to help the species. Over the past two decades, collaboration between the Wonders of the Mekong and the Cambodian Fisheries Administration has led to around 100 such fish being tagged and released, significantly contributing to knowledge on their migration patterns and habitat conditions. Dr. Hogan noted, “This information is used to establish migration corridors and protect habitats to try to help these fish survive.”
The Mekong giant catfish is deeply rooted within the region's culture, featuring prominently in folklore and even depicted in cave paintings dating back 3,000 years. The river’s ecosystem, which supports around 60 million people, hinges on the health of its fish populations and is valued at approximately $10 billion annually.
Local fishermen have become increasingly aware of their responsibility toward conservation. They are now encouraged to report accidental catches of rare species to officials, facilitating research teams to measure and tag these rare fish before releasing them. Heng Kong, director of Cambodia’s Inland Fisheries Research and Development Institute, emphasized the importance of this cooperation, saying, “Their cooperation is... conservation efforts.”
Interestingly, not only does the Mekong River support the giant catfish, but it also serves as home to other large species, such as the elusive salmon carp, previously thought extinct until its discovery earlier this year, and the giant stingray.
Brian Eyler, director of the Stimson Center’s Southeast Asia Program, called the simultaneous capture of four giant catfish the “big fish story of the century for the Mekong,” highlighting how healthy populations remain. He stated, “Hopefully what happened this week will show the Mekong countries and the world... needs to be conserved.”
Reports suggest the population of Mekong giant catfish has dwindled by as much as 95% over the last century, attributed to overfishing, the construction of dams, and destruction of their breeding grounds. Experts estimate there may only be several hundred, or potentially even fewer, adults left.
The catch of six giant catfish helps pave the way for scientists to gather more valuable data. Each fish caught was tagged and DNA samples were collected, allowing researchers to gain insights about the ecology, migrations, and habitats of this species, all aimed at ensuring their survival.
Dr. Hogan stated, “By tagging these fish, we gain... ecology, their migrations, their habitat... to try to help these fish survive.” The Mekong giant catfish holds the title of “official freshwater heavyweight champion of the world,” acclaimed for its rapid growth rate, with some individuals gaining up to 440 pounds within just six years.
The excitement surrounding this recent catch, viewed by many as indicative of potential spawning and more dynamic ecosystems along the Mekong River after years of conservation work, fosters optimism. The Wonders of the Mekong project heralded the event as "a remarkable and unprecedented event," affirming the long-term impact of both scientific diligence and local involvement.
All these developments point to the importance of continuous conservation efforts. Scientists and local communities are hopeful this landmark event signals brighter prospects for the Mekong giant catfish, and perhaps addresses environmental challenges faced by numerous freshwater species.
