The death of ten Irrawaddy dolphins in the Mekong River in Cambodia is raising serious concerns about the survival of this already critically endangered population, warns WWF.
The global conservation organization estimates that there are only 80–100 Irrawaddy dolphins left in the Mekong, and they are restricted to a 190km stretch of the river between the Cambodia-Laos border and the Cambodian town of Kratie.
"This is terrible news, making a serious situation even more critical," said Robert Mather, Senior Programme Manager at WWF's Greater Mekong Programme.
"This time of year commonly sees a peak in dolphin deaths, however ten in the last two months is particularly high and disappointing since none have been reported since May 2005."
Eight out of ten of the dead dolphins were calves, continuing the worrying trend of high mortality in baby dolphins in the Mekong. This trend has been seen for a number of years and is suspected to be due to some form of environmental pollution. However, ongoing tissue samples and chemical analysis have yet to reveal the cause.
"River dolphins like the Irrawaddy are the waters' watchdogs," said Jamie Pittock, Director of WWF's Global Freshwater Programme. "When high levels of toxic pollutants accumulate in their bodies this is a stark warning of poor water quality for dolphins and the people who live from the river."
At least one of the dead dolphins was killed by entanglement in fishing gillnets, probably the single greatest known threat to the Mekong population. Fisheries bycatch – the accidental capture of non-targeted species – is one of the greatest threats to freshwater dolphin species.