As the high-speed ferry traffic has paused due to Covid in Hong Kong, threatened species of Indo-Pacific humpback dolphins has made a comeback and their numbers have increased.
Marine scientist Lindsay Porter of the University of St Andrews said, “The mammals, also known as Chinese white dolphins and pink dolphins, were moving back into parts of the Pearl River Delta that they typically avoided due to the ferries that connect Hong Kong and Macau.”
“Dolphin numbers in the area had jumped by up to 30% since March when the ferry traffic was suspended, allowing scientists a rare opportunity to study how underwater noise affected their behaviour,” she said.
“These waters, which were once one of the busiest thoroughfares in Hong Kong, have now become very quiet,” said Porter.
A research suggested that the dolphins adapted more rapidly than expected to the quiet environment and the population was likely to rebound when such stressors were removed, she said.
Scientists think there are about 2,000 dolphins in the entire Pearl River estuary. A Hong Kong government survey from 2019 found only about 52 dolphins entered the waters around the Asian financial hub, but Porter believes the real number may be slightly higher.
“I sometimes feel that we’re studying the slow demise of this population, which can be really sad,” she said.
