The population of critically endangered dolphins in Cambodia’s Mekong River has increased for the first time after years of constant decline that pushed the species almost to the brink of extinction.
According to a new census by the Cambodian government and the World Wildlife Fund (WWF), the number of these dolphins were found to have increased to 92, 12 more than a study published in 2015.
Significance
This is the first increase in the number of the Irrawaddy dolphins (Orcaella brevirostris), ever since the first census was published in 1997 when their population was 200.
The census also revealed an improvement in the survival ratio of the species until adulthood, an increase in the number of offspring by 32 in the last three years and a decrease in deaths, which was just two in 2017, as compared to 9 in 2015.
Reasons for the dolphin population increase
The main reasons for the significant increase in the number of critically endangered dolphins include:
-Effective River patrolling by teams of river guards
-Strict confiscation of illegal gill-nets, which accidentally trap and drown dolphins
According to the WWF head in Cambodia, Seng Teak, after years of hard work they finally have reasons to believe that the dolphin population can be protected from extinction. The official also underlined the cooperation between the authorities, tourism industry and local communities as a major factor in the population rise.
Seng Teak further added that the rise in the dolphin population was an important indicator of the River’s health.
Background
• In 1997, when the first official census began, there were an estimated 200 Irrawaddy dolphins in the Mekong River.
• The figure gradually fell over the years, with only 80 left in 2015.
• The multiple threats faced by the river dolphins include:
- Habitat loss
- Bycatch or caught unintentionally
- Hydroelectric dam building
- Use for bait
- Use of illegal gillnets and poaching
• In the Mekong River, the Irrawaddy dolphins have been most affected by habitat loss and bycatch, which means getting caught unintentionally while catching certain target fish species or crabs.