ABC News April 24, 2018

Critically endangered river dolphins start to show signs of a comeback

World Wildlife Fund via AP
River dolphins in the Mekong river near Kratie province in the northeastern of Phnom Penh, Cambodia. The number of critically endangered Irrawaddy dolphins along a stretch of the Mekong River has increased for the first time in 20 years.

After decades of decline, critically endangered river dolphins in the Mekong have increased in population for the first time in a census released by the World Wildlife Fund (WWF) and the government of Cambodia.

World Wildlife Fund
A view of the Mekong river valley in Cambodia.

One of just a few species of river dolphins in the world, Irrawaddy dolphins had plummeted from 200 in 1997, the first year they were counted, to just 80 in 2015. Today the population is estimated at 97 with three dolphins born just this year.

Lor Kimsan/World Wildlife Fund
Irrawaddy dolphins surface in Cambodia's Mekong river.

Effective patrolling by teams of river guards and the strict confiscation of illegal gill nets which trap and drown the dolphins are the main reasons for the increase, according to experts.

Chakrey Un/World Wildlife Fund
River guards confiscate illegal fishing nets along a protected area of the Mekong river in Cambodia where Irrawaddy river dolphins are critically endangered.

Law enforcement efforts and increased ecotourism have helped draw attention to the dolphins while bringing economic opportunities beyond fishing.

Lee Poston/World Wildlife Fund
Researchers conduct a population survey from a boat in the Mekong river of Irrawaddy river dolphins in Cambodia.

Besides the Irrawaddy dolphins, there are only four species of freshwater dolphins in the world: the baiji in China’s Yangtze River, the boto or "pink river dolphin" in the Amazon, and the bhulan and susu dolphins in Asia’s Ganges and Indus River systems. Three other species live in both marine and freshwater habitats. All of the river dolphins in Asia are listed as critically endangered.

The Irrawaddy dolphins have been threatened for decades: hunted by Khmer Rouge in the 1970s, bombed during the U.S.-Vietnam war and subjected to destructive fishing practices after 1979.

The latest survey shows other encouraging signs, with improvements in survival rates, an increase in the number of calves and a drop in deaths.

World Wildlife Fund via AP
River dolphins in the Mekong river near Kratie province in the northeastern of Phnom Penh, Cambodia. The number of critically endangered Irrawaddy dolphins along a stretch of the Mekong River has increased for the first time in 20 years.

“River dolphins are indicators of the health of the Mekong River and their recovery is a hopeful sign for the river and the millions of people who depend on it,” said Seng Teak, country director of WWF Cambodia.

Lee Poston/World Wildlife Fund
Birds fly over the Mekong river in Cambodia at sunset.