Logo of Phnom Penh Post newspaper Phnom Penh Post - Underwater acoustic receivers set up to track largest stingray

Underwater acoustic receivers set up to track largest stingray

Content image - Phnom Penh Post
The giant stingray in Stung Treng is believed to be the world’s largest freshwater fish, excluding the beluga sturgeon. WONDERS OF THE MEKONG

Underwater acoustic receivers set up to track largest stingray

Scientists from Wonders of the Mekong and the Fisheries Administration (FiA) have set up 36 underwater acoustic receivers along the upper reaches of the Mekong River in Cambodia to better track the movements of a stingray believed to be the largest freshwater fish ever caught, excluding beluga sturgeons, which also occupy saltwater environments.

On June 13, a 42-year-old Cambodian fisherman, Moul Thun, a resident of Koh Preah village, Siem Bok district, Stung Treng province, caught the female giant freshwater stingray (Urogymnus polylepis), a species listed as “endangered” in the International Union for Conservation of Nature (IUCN) Red List.

The specimen reportedly weighed 300kg and measured 398cm from its snout to the tip of its tail, with a width of 220cm, which Wonders of the Mekong scientists noted dethroned the previous record-holder, a 293kg Mekong giant catfish caught in Thailand in 2005.

The stingray was released back into the Mekong on the evening of June 14, after it was weighed, fitted with an acoustic tag at the base of its tail, and named “Boramy” – which translates as “full moon” in Khmer – for the dusk moon shining on the horizon during its release, according to Chea Seila, the programme manager for the Wonders of the Mekong in Cambodia.

The three dozen acoustic receivers were set up along the Mekong between southwestern Kratie province where it meets Kampong Cham, to northern Stung Treng, up to the border with Laos’ Champasak province.

“These acoustic receivers are a new technology that allows biologists to understand the mysterious life processes and behaviours of living things, especially the world’s rarest and largest freshwater giant which we’ve just met and released,” Seila said.

She said the FiA, under the Ministry of Agriculture, Forestry and Fisheries, is involved in a conservation project that aims to establish a network of fishers to report catches of giant or endangered fish, including stingrays.

“We are very pleased and proud of the involvement of local fishers in the protection and conservation of rare and endangered fisheries in the Mekong River, such as the giant stingray,” she said. “We call them heroes, because without their participation, our efforts would not have been successful.”

The Mekong River originates in the Tibetan plateau, passes through China, Myanmar, Thailand, Laos, Cambodia and Vietnam, and is rich in biodiversity, but overfishing, dam construction and water pollution threaten the river’s fragile ecosystem.

Zeb Hogan, a US fish biologist at the University of Nevada, Reno who leads the Wonders of the Mekong, said: “The stingray find is evidence that the natural world can still yield new and extraordinary discoveries, and that many of the largest aquatic creatures remain woefully understudied.

“In 20 years of researching giant fish in rivers and lakes on six continents, this is the largest freshwater fish that we’ve encountered or that’s been documented anywhere worldwide.

“This is an absolutely astonishing discovery, and justifies efforts to better understand the mysteries surrounding this species and the incredible stretch of river where it lives,” he said.

MOST VIEWED

  • Typhoon Noru brings flash floods – 16 dead

    An official warned that that the 16th typhoon of the season, Noru, had brought heavy rains to areas the Mekong River and flooded thousands of homes in the provinces bordering Thailand. As of September 27, the death toll from the flooding had risen to 16. National Committee

  • Siem Reap drain canal now ‘mangrove’ promenade

    A more than half a kilometre long stretch of canal in Siem Reap has been covered and turned into a promenade to attract visitors, said Ly Rasmey, secretary of state at the Ministry of Land Management, Urban Planning and Construction, on September 16. The new pedestrianised

  • Angkor wildlife, aquarium park still to open October

    The Angkor Wildlife and Aquarium complex about 30km southeast of Siem Reap town with initial total investment of more than $70 million is reportedly still on track for an end-October opening. The park is located on a 100ha plot along National Road 6 in Kbon village, Khchas

  • Defence minister reaffirms Kingdom’s staunch support for One-China policy

    Minister of National Defence General Tea Banh has reaffirmed Cambodia’s unwavering support for the One-China policy. Tea Banh was speaking at the September 20 ceremonial handover of 117 vehicles and other military equipment donated by China’s defence ministry, held at Phnom Chumreay International Military Training

  • Deaths due to ‘lifestyle’ diseases rise in Kingdom

    The Ministry of Health has called on people to pay closer attention to their health to protect themselves from non-communicable diseases (NCDs) which it said have caused high rates of deaths in the country. Ministry secretary of state York Sambath made the call at a

  • Textile industry minimum wage now $200

    The official minimum wage for workers in textile-related sectors including garment, footwear, and travel goods for 2023 was pegged at $198, with Prime Minister Hun Sen stepping in to add $2 to the total, making it $200 per month. The Ministry of Labour and Vocational Training made the announcement