It’s 5:30 p.m. and several tourist boats linger in the middle of the Mekong River. A blood-orange sun casts a warm glow across the milky brown water, making it the ideal time to photograph the rare Irrawaddy river dolphins that congregate in deep, swirling pools. Not that these dolphins are particularly willing photo subjects, as the tourists on this day are finding out.
While marine dolphins often jump fully out of the water while swimming on a continuous path, the snub-nosed—and indisputably adorable—Irrawaddy dolphins, which grow to be up to eight feet long, will only partially breach the surface before diving back below. They may briefly pop up in one place only to reappear the next time in a random spot a few hundred feet away. The clicking of tourist cameras following each glimpse inevitably comes too late.
It’s an impressive disappearing act. Yet the most remarkable feat these dolphins have pulled off may be that they have not disappeared.
For decades, Cambodia’s Mekong River population of Irrawaddy dolphins has verged on extinction. Once believed to have numbered in the thousands, the population began to plummet in the 1970s. During the violent reign of the Khmer Rouge and the years of war that followed, the dolphins were hunted for food. Indiscriminate net fishing, in which the dolphins sometimes end up as bycatch, took a further toll, and by the turn of the millennium, there were maybe fewer than 100 left.
Some conservation measures were finally implemented in the mid-2000s when the World Wildlife Fund (WWF) partnered with the Cambodian government to support law enforcement efforts combating unsustainable fishing practices, which include using poisons and dynamite. Around this time, the Cambodian government also began promoting the dolphins as a flagship species and tourist attraction. Yet it takes time to crack down on illegal activity, and in 2015, a population census showed only 80 individuals remaining.
Then, last year, came some good news. A new survey found 92 dolphins in the Mekong River, the highest number in more than 20 years. Researchers identified nine newborn calves. This year, three more have already been found. Eng Chea San, the director general of the Cambodian Fisheries Administration, says there may be a dozen or more previously unidentified dolphins living in the river.
No one is celebrating just yet, though. The dolphin population remains well below what is considered safe to ensure its future survival. A wide array of threats persists, most notably the planned construction of a new 2,600-megawatt dam in Sambor, Cambodia, which would eat into core dolphin habitat. High mortality among young dolphins also continues to mystify scientists. (Read why Southeast Asia may be building too many dams too fast.)
Read the full article at National Geographic: https://www.nationalgeographic.com/animals/2019/04/irawaddy-river-dolphin-population-biggest-20-years/