Update on Mekong and Ayeyarwady Irrawaddy dolphin conservation


With support of the CSG, further steps were taken recently toward the conservation of two of Asia’s three riverine populations of Irrawaddy dolphins Orcaella brevirostris: in the Mekong of Cambodia and Laos and in the Ayeyarwady of Myanmar.


Mekong River Irrawaddy Dolphins

The critically endangered Mekong River population has been the subject of ongoing global interest and concern, and an ad hoc team of international conservation scientists has been providing advice to local conservationists in the Cambodian Fisheries Administration and WWF-Cambodia since 2009 (see reports from 2009 and this background summary). Since 2012 and the landmark Kratie Declaration on the Conservation of the Mekong River Irrawaddy Dolphins, major changes have occurred in the governance and management of dolphin conservation efforts within both the Cambodia government and WWF-Cambodia. In view of those changes, local partners decided to organize a workshop in Phnom Penh to assess progress on implementation of the recommendations from the Kratie Declaration and to update Cambodia’s river dolphin conservation strategy. Randall Reeves co-chaired the event which was well attended by local government and civil society representatives. CSG members Bob Brownell, Andy Read, Brian Smith, Randy Wells and Gerry Ryan as well as Frances Gulland of the SSC Wildlife Health SG, Helene Marsh of the SSC Sirenia SG and current president of the Society for Marine Mammalogy, and Peter Thomas of the US Marine Mammal Commission also participated in the workshop.

The workshop affirmed that significant progress had been made since the Kratie Declaration, notably in the reinforcement of patrolling activities by river guards and the refinement of protocols to investigate mortality. Nonetheless, the group concluded that entanglement in gillnets remains the most critical and immediate threat to the survival of dolphins in the Mekong and that concerted efforts are needed to address this issue even more vigorously. Also, other threats have emerged, most importantly the notification by Laos of its intention to proceed with construction of a hydropower dam at Don Sahong near the Cambodia border, starting later this year. Proposals for hydropower dams cover almost the entire current range of the Mekong dolphins. Construction of the Don Sahong dam as well as the Xayaburi dam farther upstream in a major tributary of the Mekong in Laos would set a poor precedent as the proliferation of dams in the Mekong would almost certainly spell the end for dolphins in this river system (WWF is campaigning to prevent construction of the Don Sahong dam). The workshop made a series of recommendations related to strengthened research on demography and mortality of the dolphin population as well as more rigorous analyses of the booming dolphin-watching tourism industry. The full report of the workshop is available here.


Ayeyarwady River dolphins

Given the assembled expertise on river dolphin conservation, the conveners took advantage of the opportunity to hold a separate discussion on the deteriorating situation of the critically endangered dolphin population in the Ayeyarwady River (click here for report). Irrawaddy dolphins in both the Mekong and Ayeyarwady share similar conservation challenges. These include low population size, a declining range, suspected high mortality from gill-net entanglement, illegal electro-fishing, and plans for constructing hydroelectric dams in the mainstem and major tributaries. Compared to the Mekong, much less is known about demography and mortality of dolphins in the Ayeyarwady. As a consequence, a great deal of the discussion focused on identifying information gaps and appropriate strategies for filling those gaps. The long-standing co-operative fishing relationship between dolphins and cast-net fishermen in the Ayeyarwady appears to have broken down due to diminished catches and the disturbance caused by electro-fishing. This illegal fishing technique is practised extensively in the Ayeyarwady but is particularly difficult to stop because it is done surreptitiously by armed gangs at night.

In addition to highlighting the potential disappearance of the human-dolphin cooperative fishery and the ecological problems caused by electro-fishing, the group made recommendations and expressed concern about topics including the importance of conducting rigorous surveys; the apparent resurgence of gold-mining in the river mainstem; the need to understand  movement patterns with respect to population fragmentation; the value of establishing a  mortality monitoring network and a site-specific necropsy protocol that includes an examination for external signs of contact with fishing gear; and the importance of conducting a rigorous assessment of the potential impacts of planned dams. Finally, the group recognized that the participation of international experts has been extremely useful in helping to establish conservation measures and research initiatives in the Mekong River. They therefore suggested that a similar approach would be useful in Myanmar.

After the workshop, Helene Marsh travelled to Yangon to meet with Aung Myo Chit, a local conservationist in Myanmar who is in the process of establishing a foundation for the protection of Irrawaddy dolphins, and staff from the Wildlife Conservation Society Myanmar Program and the Myanmar Department of Fisheries. Together with these partners, Marsh developed a proposal to convene the First International Workshop on the Management and Research Priorities for the Ayeyarwady Dolphin, tentatively planned for late 2014 or early 2015.