Areas along the Mekong River are set to become hotspots in the Kingdom for conducting scientific studies on the unexpected survival of endangered species and other biodiversity-related subjects, according to officials.
The remarks came after scientists from the Wonders of the Mekong project and the Cambodian Fisheries Administration (FiA) announced that a 300kg giant freshwater stingray (Urogymnus polylepis) caught by a fishermanin the Mekong on June 13 was the world’s largest freshwater fish ever officially weighed and measured – a claim that excluded beluga sturgeons, which technically also inhabit saltwater environments.
The endangered stingray, caught in Koh Preah village of Stung Treng province’s Siem Bok district and named “Boramy” which translates as “full moon” in Khmer, dethroned the previous record-holder, a 293kg Mekong giant catfish caught in Thailand in 2005.
In Posoeun, director of the Stung Treng provincial Department of Tourism, said Boramy’s discovery would be a major draw for inquisitive marine biologists and other researchers to unravel the secrets to the survival of endangered species in the Cambodian stretch of the Mekong River.
“The Mekong River in Cambodia is a safe haven for all kinds of living species, especially some of the world’s rarest and most endangered, such as the Irrawaddy dolphin and the world’s largest stingray, and so on,” he told The Post.
“Thus, in the future, the Mekong River in Cambodia will be an important destination in Southeast Asia for researchers who are studying the survival of these rare and endangered species,” he said, claiming that the other Mekong countries – China, Myanmar, Thailand, Laos and Vietnam – do not have populations of these creatures as large as Cambodia’s.
Posoeun said his team is currently documenting the areas where giant stingrays live, with plans to publicise the information in hopes of advancing understanding of the flat-bodied fish.
At the same time, he called on the ecotourism community in areas of Stung Treng province near the Mekong’s deep dolphin pools to advertise the locations where the stingrays live to local and foreign visitors who may be there to see the aquatic mammals. He suggested that the uptick in interest would lead to tour groups making the journey in hopes of catching an exceedingly rare glimpse of the rays.
Pheng Boeun is the chief of the Koh Preah Fisheries Cooperative, which is based in the area where Boramy was caught and provides tour boat services to dolphin pools Anlong Kaingkonsat, Anlong Koh Santuk and Anlong Tbong Khla in Siem Bok.
He told The Post that members of his cooperative have been calling attention to the mysteries of the giant freshwater stingray since a fisherman caught a 180kg specimen last month.
“In general, however, apart from when they are caught by fishermen, we rarely see a giant stingray appear on the surface of the water like we do with dolphins.
“But there are actually a lot more of them left alive in the river than the findings of Wonders of the Mekong’s scientists would suggest,” he claimed.
Boeun shared that fishermen from his cooperative once encountered a fever, or group, of more than 10 stingrays at the Anlong Kainkonsat with each weighing from 30-40kg, although he admitted never having seen one that weighed anywhere near 300kg like Boramy.
He said there are two types of giant stingrays, distinguished by black and red tinges, which the community has dubbed “buffalo stingrays” and “cattle stingrays”, respectively.
Nonetheless, scientists have yet to determine how many subspecies of giant freshwater stingray there actually are, although most are familiar with the “buffalo” type, which prefer to live in deep pools with clean environments, according to Som Vichet, director of Stung Treng FiA Cantonment.
“Due to the biology of freshwater stingrays, they do not appear on the surface of water and allow tourists to see them like dolphins do.
“So the areas where they live are not going to be much in the way of tourist destinations for the general public in that sense, but it will be a very attractive destination for scientific researchers who focus on freshwater species,”he said.
Vichet said that the giant freshwater stingray is not only found in the Koh Preah area of Siem Bok, but also in a Ramsar site of Siem Pang district. To date, however, researchers have not provided formal population estimates or summaries of upstream and downstream movement patterns.
All that may be changing though, because two weeks ago scientists at the Wonders of the Mekong deployed 36 underwater acoustic receivers along the upper reaches of the Mekong River in Cambodia to track the movement and behaviours of Boramy, who was released back into the Mekong on the evening of June 14, after she was fitted with an acoustic tag at the base of her tail.
The scientists have yet to collect data from the devices to analyse and learn more about her mysterious underwater life.