Rare pink dolphins have returned to the waters between Hong Kong and Macau after coronavirus halted ferries, but scientists remain deeply concerned about their long-term survival in one of the world’s busiest sea lanes.
“Today we encountered three different groups of dolphins — six adults and two sub-adults,” Naomi Brennan a conservationists said.
“They were engaging in a range of behaviour, from feeding to travelling and socialising.”
Over the past 15 years the population of dolphins have fallen by 70-80 percent. But amid the pandemic their numbers have bounced back.
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.
“These areas seem to be important for feeding and socialising. So it’s great that there’s this refuge for them,” added Brennan, a member of Porter’s team.
The Pearl River Delta is one of the most industrialised coastal areas on Earth. As well as Hong Kong and Macao, it includes Chinese mainland megacities like Shenzhen, Guangzhou and Dongguan, and is home to some 22 million people.
And aside from heavy shipping traffic, the dolphins’ key habitat has been subjected to a host of large-scale developments, including the construction of Hong Kong’s airport on reclaimed land and the world’s longest sea bridge connecting the financial hub to Macau and Zhuhai.
According to the WWF, there are only an estimated 2,000 pink dolphins left in the Pearl River Delta, the minimum number that conservationists believe are needed to sustain the species’.