Fisherman Hauls in the Largest Freshwater Fish Ever Recorded

A fisherman in northern Cambodia has caught the single biggest freshwater fish the world has ever seen. Researchers told VICE World News on Monday that the giant freshwater stingray, which measured 13-foot snout-to-tail and at 300 kilograms weighed twice as much as an average lowland gorilla, was accidentally caught in a remote stretch of the Mekong River on June 13.

After being measured, weighed, and filmed, the colossal female—named “Boramy," or full moon in Khmer—was fitted with an acoustic tag before it was released back into the murky depths of the Mekong. This will allow researchers to track and monitor its movements, aiding conservation efforts. 

In a June 20 press release by the USAID-funded Wonders of the Mekong project, researchers hailed the discovery as a historic occasion, and highlighted the importance of better understanding “the mysteries surrounding this species and the incredible stretch of river where it lives.” 

The discovery is also, however, a stark reminder of the unique biodiversity and megafauna that is being threatened by increasing development and human activity along the 4,350 kilometre-long Mekong river—Southeast Asia’s most important waterway, home to more giant fish species than any other river on Earth. 

“This is an astonishing, globally significant event, and one that also holds deeper meaning because most species of giant freshwater fish face extinction,” Zeb Hogan, a fish biologist at the University of Nevada, Reno and lead researcher at Wonders of the Mekong, told VICE World News.

The giant freshwater stingray is one of only a few remaining giant fish species in the Mekong, which in recent years has been heavily impacted by pollution, overfishing, and the construction of dams that have lowered water levels in downstream countries such as Laos, Vietnam, Thailand, and Cambodia.

Experts believe that these controversial dams, the largest of which have been built near the river’s source in southern China, are contributing to a protracted, devastating, and ongoing drought in mainland Southeast Asia.

A report by the World Wildlife Fund back in 2010 warned that the Mekong’s freshwater megafauna would be driven to extinction by the relentless construction of dams, which can represent an insurmountable barrier for the river giants and prevent them from reaching spawning grounds. Nine years later, the first comprehensive study into global populations of freshwater megafauna found that they had declined by an average of 88 per cent worldwide—and the situation in the Mekong was flagged as particularly worrisome.

Authors of the report noted that some species of freshwater megafauna in the Mekong river and the Yangtze river in China may already be extinct, while populations of others have declined by 95 to 99 per cent. Habitat degradation and fragmentation due to dams was cited as a major factor.

“The results are a wake-up call to us about the plight of these species,” Hogan said at the time. “Many of them are at risk of extinction, and almost all of them need our help. It's a race now to see what can be understood and protected before it's too late.”

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