The Mekong River Irrawaddy dolphin’s round and beakless head is striking—reminding some of the iconic Pac-Man. But unlike the enduring video game character, this dolphin has been in steady decline since the 1970s. The International Union for Conservation of Nature (IUCN) lists the Irrawaddy dolphin’s Mekong River subpopulation (Orcaella brevirostris) as critically endangered, and they are in imminent danger of extinction; experts estimate that fewer than 70 individuals remain.
The Irrawaddy dolphin is a euryhaline species—one that can survive in a range of salinities. While typically oceanic, this unique physiological characteristic naturally extends the species’ habitat range into coastal waters, brackish lakes, and freshwater rivers. Subpopulations of Irrawaddy dolphins are found in areas from the Bay of Bengal to New Guinea and the Philippines. The Mekong River dolphin, one of only three freshwater subpopulations, currently inhabits a 118-mile freshwater stretch of the Mekong River in central Cambodia and into southern Laos.
While the Mekong River dolphins have historically displayed a mutualistic relationship with traditional fishermen (the dolphins have been known to drive fish into nets for rewards), the dolphins have succumbed to human-wildlife conflicts in the last few decades brought on by modern fishing methods, habitat degradation, and capture for the entertainment industry. Post-mortem examinations of adults indicate that gillnet entanglement is the main cause of death. Due to the increasing levels of bycatch and habitat loss in recent years, it is suspected that the Mekong subpopulation will face a further 30 percent reduction in size over a period of three generations.
In fact, the major threat across all subpopulations of Irrawaddy dolphins is bycatch. The IUCN lists five of the seven subpopulations as critically endangered, primarily due to drowning in fish nets. The ability to live in fresh water often brings these dolphins closer to human-influenced areas, where they are accidentally captured and drowned in gillnets, dragnets, and bottom-set crabnets.
Even though these dolphins have historically thrived in areas with humans, it is becoming all too clear that they no longer coexist with us so easily. The IUCN lists Cambodia, Laos and Vietnam as the dolphins’ native countries; in fact, in the 1970s, their range had extended beyond the Mekong into the Sekong River and its tributaries, and stretched south of Kratie into central Cambodia to Phnom Penh. However, dolphins now only rarely, if ever, ascend the rivers north of the Mekong’s confluence with the Sekong River. Downstream from Kratie to Phnom Penh, children were unaware of the existence of the dolphins, even though locals reported observing dolphins every day in both low and high water seasons before 1975 (Isabel Beasley, pers. comm.). As a further indication of the significant decrease in range over the last few decades, no Mekong dolphin has been sighted in Vietnam for nearly four decades other than a single carcass found in a fishing-net near the Cambodia/Vietnam border in 2002.
In general, to maintain populations, it is recommended that yearly removals of small cetaceans—which include all deaths and capture for captivity—should not exceed 1.2 percent of the population size. On average, four Mekong River dolphins die each year from gillnet entanglement. Assuming a high total population estimate of 69 (less than 50 of whom are mature individuals), four deaths represents 5.8 percent of this population. Given that even a single death per year exceeds the recommended level of yearly removal, it is clear that the current rate of incidental mortality would lead to the population’s demise.
Despite these bleak numbers, international bodies, a number of local organizations with support from their communities, and the Cambodian government are now collaborating to prevent the extirpation of this particular subpopulation. In 2004, after the IUCN listed the Mekong River dolphins as critically endangered, the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) transferred the Irrawaddy dolphin from Appendix II to Appendix I, forbidding all commercial trade in the species. The Convention on the Conservation of Migratory Species of Wild Animals also lists various populations of Irrawaddy dolphins on either its Appendix I or Appendix II of threatened species. The Mekong dolphins are listed under Appendix I, and the Parties are encouraged to provide immediate protection and support research related to their conservation.
Recognizing the need to go beyond the protections afforded by CITES, especially given that most deaths are due to incidental take and not for trade purposes, Cambodia is considering a new fisheries law and royal decree to protect and conserve all cetaceans, including Irrawaddy dolphins, in the country’s eastern provinces—which includes a segment of the Mekong River above Kratie corresponding with the dolphins’ range. While other range states for the species—Bangladesh, India, Laos, Malaysia, and Thailand—prohibit the direct taking of cetaceans, Cambodia’s recently proposed fishing regulation goes further toward conservation by banning fish cages and gillnets, thereby addressing the bycatch issue.
This progressive decree, introduced in March 2012 by Cambodia’s Tourism, Agriculture, and Transportation ministries, comes on the heels of the January 10–12 Mekong Irrawaddy Dolphin Conservation Workshop, held in Kratie and supported through funding by AWI. At the workshop, Cambodian and international experts as well as government officials—including the Fisheries Administration of the Ministry of Agriculture, Forestry and Fisheries—collaborated to produce 25 recommendations aimed at understanding and conserving the Mekong River dolphins.
The recommendations elucidate needed resources and provide guidelines to facilitate and help standardize studies concerning mortality causes, population dynamics, behavior and ecology, and fisheries management. While there are a multitude of steps to be taken, the recommendations are based on practical needs that can and must be met in order to understand the problem and formulate strategies.
At the close of the workshop, three parties—the Commission for Dolphin Conservation and Development of Mekong River Dolphin Ecotourism Zone, the Fisheries Administration, and the World Wide Fund for Nature—signed the “Kratie Declaration on the Conservation of the Mekong River Irrawaddy Dolphins,” committing to develop a strategy for implementing the recommendations and to reconvene in January 2013 to review progress.
Conservation efforts must be conducted with a level of sensitivity that not only considers the animals’ intrinsic value, but also acknowledges other powerful factors such as politics, economics, and the necessary support from local fishermen and other residents who share the environment. Thus, these recommendations were made with the recognition of the economic role that the dolphins play in northeastern Cambodia as the principal tourist attraction.
This acknowledgment of the relationship between animal protection and collaboration with local communities will lead, hopefully, to mutually supportive fundraising, effective law enforcement, and encouragement of livelihoods that do not pose a threat to the dolphins. Another vital outcome of this effort is a shared sense of urgency and optimism—the latter of which has been absent for far too long—that there is a future for the Mekong River dolphins.