Mekong Irrawaddy dolphin numbers stabilised, but more collective and unprecedented action urgently needed to save them from extinction

Posted on October, 23 2020

The Irrawaddy dolphin population in the Mekong River numbers just 89, the 2020 survey report led by the Fisheries Administration and WWF revealed today. Scientists suggest that the population remains stabilised for the last 3 years.

The survey’s findings also indicate a positive survival rate of calves through to adulthood, with first highest recruitment rate of 4.22% ever documented across all surveys in the past decade, signalling gradual recovery trend of the dolphin population.
The Irrawaddy dolphins (Orcaella brevirostris) inhabit a 180km stretch of the mainstream Mekong River between Kratie, Cambodia and Khone Falls on the border with Lao PDR. Scientists however expressed concerns over the absence of animals in six of nine deep pools along the Mekong River, where they historically used to live before. Dolphins have been observed during the surveys to inhabit only three deep pools of Kampi, Koh Kaun Sat and Cheu Teal.
It is important to also note that 25 dolphins documented in the 2017 report were not photographed during the 2020 survey. Scientists suspect that during the survey period these animals may have migrated outside of their home range to small channels of the river, which are not covered by the regular survey effort. Going forward, the survey team will continue to monitor the situation very closely.
The population is ranked as critically endangered on the IUCN Red List, the highest international threat ranking for endangered species, and Irrawaddy dolphins are fully protected under the Cambodia’s Fisheries Law. “The Fisheries Administration acknowledge the law enforcement efforts by the river guards in cooperation with the provincial and local authorities in Kratie and Stung Treng provinces, which have contributed to prevent and stop illegal fishing in the protected dolphin habitat areas,” said H.E. Srun Limsong, Deputy Director-General of the Fisheries Administration.
The dolphins however continue to face great danger. Gill nets, development of upstream dams, over fishing, illegal fishing practices such as electrofishing, poisonous bait, dynamite fishing, are among major known treats to the survival of the Irrawaddy dolphins in the Mekong.
“Although the 2020 survey result confirmed that the species number is stabilised, the population size of the animal is still small, thus stronger conservation action is needed,” said Mr Seng Teak, WWF Country Director.
“To ensure this critically endangered species population can thrive, their habitats must be free from illegal fishing activities, with abundant availability of prey or food. Increasing law enforcement, accelerating livelihood development and addressing the transboundary issues including the water flows and climate change are the must-do,” Mr Seng Teak said.
The Fisheries Administration and WWF are actively working with the provincial authorities, local communities and other partners to implement the recommendations described in the 2020 survey report, including, among others, strict enforcement of the fisheries law and the ban of illegal gill net use in the protected dolphin habitat, continued provision of alternative livelihoods opportunities in communities along the Mekong, community outreach and environmental education and continued robust research and monitoring of the species population. These actions are of paramount importance for the future survival of Mekong river dolphins.
Link to photos:
Mekong dolphins in Cambodia's Mekong River
© Tan SomethBunwath / FiA / WWF-Cambodia
Special thanks to our donors for the Irrawaddy dolphin conservation in Cambodia