HONG KONG: Rare pink dolphins are returning to the waters between Hong Kong and Macau after the coronavirus pandemic halted ferries, but scientists remain deeply concerned about their long-term survival in one of the world’s busiest sea lanes.

The tell-tale flash of pink leaping from the waters alerts Naomi Brennan to the presence of a local Chinese white dolphin and she jots the animal’s location into a GPS device.

Conservationists like Brennan regularly board boats in the Pearl River Delta to document how the mammals, known for their eye-catching pink colouring, are faring.

“Today we encountered three different groups of dolphins — six adults and two sub-adults,” she explained.

“They were engaging in a range of behaviour, from feeding to travelling and socialising.” For years keeping tabs on the dolphins has been a disheartening task.

The population has fallen by 70-80 percent in the past 15 years in what is one of the world’s most industrialised estuaries.

But this year their numbers have bounced back — and they have the pandemic to thank.

Ferries between Hong Kong and Macau have been suspended since February, providing local marine scientists an opportunity to study how the mammals have adapted to the “unprecedented quiet”.

“We’re seeing much larger group sizes as well as much more socialising, mating behaviour, which we hadn’t really been seeing for the last five years or so,” said Dr Lindsay Porter, a Hong Kong-based marine scientist.

According to Porter’s research team, the number of pink dolphins has increased by roughly a third in those waters since March.

Published in Dawn, October 17th, 2020