The population of Irrawaddy dolphins in the Mekong River has risen for the first time in years, raising hope for the critically endangered species.
Wildlife activists from WWF and the Cambodian government broke the good news on Monday, saying a new dolphin was born last week and there has now been three newborns this year.
“Results from a WWF and Government of Cambodia census released today show that the population of critically endangered river dolphins in the Mekong has risen from 80 to 92 in the past two years – the first increase since records began more than 20 years ago,” a statement by WWF said.
“Effective river patrolling by teams of river guards and the strict confiscation of illegal gill-nets, which accidentally trap and drown dolphins, are the main reasons for this historic increase. Over the past two years 358km of illegal gill-nets – almost double the length of the dolphins’ remaining home range – have been confiscated from core dolphin habitat.”
Seng Teak, country director for WWF Cambodia, said: “The tour boat operators are the secret ingredient in this success story as they work closely with law enforcement to report poaching and help confiscate illegal gill-nets.”
The first official census in 1997 estimated that there were 200 Irrawaddy dolphins in the Mekong, but that figure fell steadily due to the river mammals getting caught in fishing nets plus habitat loss, and there only 80 left in 2015.
But the surveys have suggested “encouraging signs” for the dolphins with more of the animals reaching adulthood, plus an increase in the number of calves and a drop in overall deaths. Just two dolphins died last year compared to nine in 2015.
A graph showing the rise in Irrawaddy dolphins in the Mekong after the serious decline in numbers over recent years. Source: WWF
Eng Cheasan, head of the Cambodian Fisheries at the Ministry of Agriculture, said the Mekong dolphins are considering a national treasure and that latest news reflects many years of continuous work to protect the species.
The surveys undertaken by WWF and government officials cover 190km of the main channel of the Mekong from Kratie in Cambodia to the Khone Falls in southern Laos. Teams photographed the dolphins and compared distinctive marks on their backs and dorsal fins against a database of known dolphins, the wildlife group said.
Today’s statement is the first positive news for years about marine life in the Mekong, which has suffered severely from dams both in the upper reaches in China, plus several that companies have been building in the midstream in recent years just north of the area where these dolphins are found.
There is still enormous concern about the impact of dams being built in the midstream, such as the Xayaburi Dam near Luang Prabang and another in the Siphandon area in southern Laos. Fishermen on Cambodia’s huge Tonle Sap lake have suffered declining fish yields for years and farmers in the Mekong Delta in Vietnam have been hit hard by growing saltwater intrusion in an area that was once lauded as the country’s rice bowl.