An important transboundary pod of Mekong river dolphins may be one individual away from extinction, wildlife officials and local fishermen said, with research showing only one dolphin remaining after a barrage of man-made threats.

The number of dolphins in the important Anlong Chuteal region, which straddles the Cambodia-Laos border, has been in decline since at least 2007, when photo-identification surveys found eight dolphins. Their numbers have dropped steadily, to six in 2012, three in 2018, and just one this year.

“The very small cross-border population of dolphins, which is thought to have been isolated for some time from the larger groups downstream in Kratie and Stung Treng, is essentially lost,” said Dr. Randall Reeves, chairman of the International Union for Conservation of Nature Species Survival Commission’s Cetacean Specialist Group.

The Mekong dolphin, also known as the Irrawaddy dolphin, plays an important role in local life and culture. The animals provide a key tourist attraction, and their presence has contributed to growing ecotourism opportunities in the area.

“The Mekong dolphins are regarded as sacred animals by Cambodian people,” said Kung Chanthy, a local community fisheries chief. “Cambodian people believe that where there are dolphins, there are fish. Without fish and dolphins, our livelihoods will be destroyed.”

The dolphins’ main threat comes from fishing nets, which trap them underwater and result in drowning. Other dangers include overfishing, river flow disruptions from upstream dams and destructive fishing practices like electrofishing.

The government in recent years has taken greater action to protect the dolphins. Officials regularly seize fishing nets and confiscate illegal fishing equipment. As a result, dolphin numbers in the main population group around Kratie and Stung Treng have stabilized.

Yet further north, around Anlong Chuteal, dolphins roam areas that cross international borders, making conservation challenges all the more difficult.  “We are witnessing the tragic loss of the transboundary population of this iconic species,” said Dr. Uzma Khan, Asia coordinator for the River Dolphin Rivers Initiative at WWF. “It’s truly devastating.”