(Irrawaddy dolphin; Credit: World Wildlife Fund)
The Irrawaddy dolphin, considered sacred to many people in Cambodia and Laos, has declined to just 85 individuals in Southeast Asia's Mekong River, according to a World Wildlife Fund assessment. Leading researchers now conclude that the population is at high risk of dying out altogether.
"This low number, combined with very low calf survival rates, means that these dolphins are frighteningly close to extinction," WWF spokesperson Caroline Behringer told Discovery News.
Li Lifeng, director of WWF's Freshwater Program, echoed the concern about calves in a press release statement.
He said, "Evidence is strong that very few young animals survive to adulthood, as older dolphins die off and are not replaced."
Li and his colleagues used a technique called "photographic mark-recapture" to count the dolphins. This involves identifying specific individual dolphins through unique markings on their dorsal fins. The method, adjusted to focus on other unique identifying features, has previously been used to estimate whale, tiger, horse, leopard and other animal populations.
Eighty-five is actually a higher amount than expected, but that's likely just due to improved surveying efforts.
"With a larger dataset and recent analytical advances, previously unidentifiable dolphins which had few marks on their dorsal fins have been included," Li explained.
Three populations of Irrawaddy dolphins exist: in the Mekong River, the Irrawaddy River in Myanmar, and the Mahakam River in Indonesia. This latest survey only covered the Mekong population, but all three populations are critically endangered. Gill net entanglement remains a constant threat.
"These dolphins are at high risk of extinction by their small population size alone," said Barney Long, WWF's Asian Species Expert. "With the added threats of gill net entanglement and high calf mortality, we are seriously concerned about their future."
A secondary problem affects people in the areas where the dolphins live. Because these marine mammals are sacred, many locals and tourists want to see them. Lucrative dolphin and whale-watching ecotourism therefore thrives in the area, with many using it as their primary source of employment and income.
No dolphins would mean few associated ecotourist dollars.
Since one part of the dolphin population surveyed - numbering just seven or so individuals - is located on the Cambodia/Laos border of the river, conservation efforts must involve at least these two countries working together to protect the animals.
"Our best chance of saving these dolphins from extinction in the Mekong River is through joint conservation action," said Rebecca Ng, head of WWF's Mekong program. "WWF is committed to working with the Fisheries Administration, the Dolphin Commission, and communities all along the river to reverse the decline and ensure the survival of this beautiful species."
The dolphin's beauty and playful nature is captured here: