In the Cambodian stretch of the Mekong, the births of six Irrawaddy dolphin calves were confirmed this year. This has raised the estimated size of the local population to 118 individuals. The event occurred along a 120-kilometre stretch of the river in Kratie and Stung Treng provinces.
Irrawaddy dolphins (Orcaella brevirostris) are the only cetaceans in these waters. In Cambodia and Laos they are revered as sacred animals embodying the spirit of the river. For riverside communities they also bring income from ecotourism, especially in places such as the Kampi deep pool in Kratie.
The population in the Cambodian Mekong is markedly lower than estimates from the late 1990s, when about 200 individuals lived here. The main threats are entanglement in gillnets, which is especially dangerous for calves, illegal electrofishing and habitat degradation. More than 160 dams in the river basin are altering the hydrology and the composition of fish communities on which the dolphins depend.
Since 2012, protected zones where gillnets are banned have been in place along a 180-kilometre stretch of the river. Electrofishing is officially banned throughout the country. Joint patrols, monitoring and work with local residents appear to have contributed to the absence of dolphin deaths in recent years and to the birth of new calves.
Officials and conservation organisations note that the birth of six calves is an encouraging signal. However, the population remains vulnerable, and without further reduction of threats, recovery may prove fragile.
Protecting these animals requires constant attention to illegal fishing and to the impact of infrastructure projects on the river.
