Dolphin conservation groups and government officials are expressing grave concerns over the decline in the number of dolphins present at the Chheu Teal trans-boundary pool of the Mekong River at the Laos-Cambodia border, saying that if this alarming trend is not halted, it will lead to the extinction of this important mammal.

The joint press release on October 24 stated that the isolated population of Irrawaddy dolphins residing in the Chheu Teal trans-boundary pool is on the verge of disappearing.

Periodic photo-identification surveys indicate that the number of dolphins fell from seven in 2009 to six in 2012 and then three in 2018 and now just one dolphin remains there in 2021.

The Dolphin population in the trans-boundary pool was small to begin with but it began sinking even lower due to changes to the Mekong River upstream from the pool, the limited presence of law enforcement around the trans-boundary pool and natural deaths to due aging.

Poum Sotha, Director General of Fisheries Administration, said that the near-total disappearance of the trans-boundary dolphin population is an alarming signal about what the future holds for the world’s threatened species.

“Currently, although only one dolphin remains in the trans-boundary pool, the fisheries administration will reinforce the area with officers for its protection and strengthen our cooperation with Laos in managing this valuable fishery resource. The dolphins are fully protected under Cambodia’s fisheries law and the sub-decree on management and protection of the Mekong dolphins,” he said.

Major known causes for the decline of the trans-boundary pool population have included dolphins drowning after being caught in gill-nets which then left them unable to surface for air periodically as aquatic mammals must, disruptions to the river’s flow from upstream dams, overfishing which eliminates food resources for the dolphins as well as killing them directly and the use of damaging and illegal fishing practices such as electro-fishing, the press release said.

It said that in 2020 and the first half of 2021, the river patrols covering the dolphins’ habitat in Kratie and Stung Treng provinces removed nearly 112,000 metres of illegal gill-nets and more than 131,000 metres of illegal long-hook lines. Patrols also stopped 20 incidents involving boats engaging in electro-fishing.

The very small trans-boundary 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.

“We are witnessing the tragic loss of the trans-boundary population of this iconic species. It’s truly devastating,” said Dr. Uzma Khan, Asia Coordinator for the River Dolphin Initiative at the WWF and a member of the IUCN-SSC Cetacean Specialist Group.

She called on the Lao and Cambodian governments to recognise the near extirpation of the trans-boundary dolphin population and put a firm stop to gill-net use and other illegal fishing methods in and around the trans-boundary pool and then urgently devise a plan to restore the habitat by maintaining water flows that allow for the movement of both dolphins and the mega-fish species.

Kung Chanthy, chief of the community fishery network in Borei O’Svay commune of Sen Chey district in Stung Treng province said the dolphins support the community’s livelihoods and provide an important source of income and jobs for communities involved in dolphin-watching tourism.

“The Mekong dolphins are regarded as sacred animals by the Cambodian people,” he said.“Cambodian people know that where there are dolphins, there are fish. And without fish and dolphins, our livelihoods will be destroyed,” he added.

Sotha and WWF-Cambodia country director Seng Teak have agreed that the fisheries administration and WWF will set up a memorial dolphin statue at the Chheu Teal pool to remind the public and future generations that dolphins once called these waters home.

Sotha urged authorities from Laos and Cambodia to closely collaborate to co-manage the trans-boundary fisheries for the benefit of local communities in both countries and to help ensure the survival of the remaining Mekong dolphin.