New Population Survey Reveals Rate of Decline of Critically Endangered Mekong Freshwater Dolphin Slowing | WWF

New Population Survey Reveals Rate of Decline of Critically Endangered Mekong Freshwater Dolphin Slowing

Posted on 10 November 2015
New-born Irrawaddy Dolphin
© Kimsan LOR / WWF-Cambodia
Cambodia, Phnom Penh, Nov. 10, 2015 – WWF Cambodia and Fisheries Administration celebrate a campaign to raise awareness on protection of the critically endangered Mekong Irrawaddy Dolphin in Kratie province on November 10th, 2015. This is an annual event for international fresh water dolphin day, and it is to celebrate the Irrawaddy dolphin as a unique part of Cambodia's living natural heritage and think carefully about how we all can help conserve it for the future generation.

There will be around 300 to 500 participants coming from different stakeholders including students, teachers, monks, local communities, river guards, delegates and representatives of provincial and national Fisheries Administration, local authorities, private companies, and other civil society organizations coming together to share a common goal of conserving this critically endangered species, and to raise the awareness to other people. Participants will roam within Kratie town to raise the awareness to the general public.

At the same time of celebrating this event, there will be a hot release of Mekong Irrawaddy dolphin population. In a rare piece of good news the rate of decline of the critically endangered species is slowing; despite serious threats from gillnet fishing, according to a new population survey by WWF-Cambodia and the Cambodian Fisheries Administration.

The new population is 80 individuals, which is five less than in 2010 but most importantly, their annual rate of decline has slowed from approximately 7 percent per year in 2007 to the current rate of 1.6 percent in 2015. This is thanks to years of work by the Fisheries Administration and WWF in protecting their habitat and removing gill nets, a major cause of dolphin mortality.

“It’s not time to celebrate quite yet, but we have reason to hope that the Mekong’s majestic dolphins are on the way back,” said Sam Ath Chhith, Country Director of WWF-Cambodia. “Now is not the time for complacency. We need to re-double our efforts to protect the dolphins and make sure that the destructive Don Sahong Dam and others like it are not built on the Mekong River.”

The survey shows the recruitment of new individuals – juveniles who survive to adulthood – is estimated at 0.8% per year. This is a ray of hope for the recovery of Mekong Irrawaddy Dolphins because prior to 2013, recruitment was estimated at zero. While scientists finally have evidence of limited recruitment, it is still less than the mortality rate.
These results suggest that whilst the population continues to decline, the rate of decline appears to be slowing. Coupled with the increasing recruitment rate, it gives scientists hope that the species can survive if mortality rates can be reversed.

“The result of the survey gives us a clear number of the endangered Mekong Irrawaddy Dolphin, which is considered our country’s living national treasure, and it reflects our many years of continuous efforts put into protecting this species, ” said His Excellency Eng Cheasan, Director General of Fisheries Administration of the Ministry of Agriculture, Forestry and Fisheries. “We will continue our conservation efforts to recover its population by eliminating all threats to the survival of Irrawaddy dolphins.”

One of the most ominous threats to Mekong Irrawaddy dolphins is the 11 proposed hydropower dams on the Mekong river’s mainstream. One of these – the Xayaburi Dam in northern Laos – is almost complete, while another on the Don Sahong channel in southern Laos, is planned to break ground in the near future. The dams have the potential to irrevocably disrupt fish migration, endangering the world’s largest inland fishery and the main source of protein for the region’s 60 million people.

These dams could also deal a crushing blow to the Mekong’s dolphins. The Don Sahong dam site is less than two kilometres upstream from a deep river pool, which contains Laos’ last four Irrawaddy dolphins. Blasting alone could seriously damage their sensitive hearing. Further downstream in Kratie, a much larger population of dolphins is also threatened by the dam that could drastically reduce its food supply.

“The Don Sahong Dam is an ecological time bomb that threatens the food security of millions of people and a population of critically endangered Irrawaddy dolphins,” said Sam Ath Chhith, Country Director, WWF-Cambodia. “The dam will have negative impacts on the entire Mekong River ecosystem all the way to the Delta in Vietnam. We ask the Laos Government and the developer – Malaysia’s Mega First Corporation Berhad – to reconsider this ill-fated decision and wait until further studies are completed on the environmental and social impacts and all legal options and requirements under the Mekong Charter have been completed.”