The number of Chinese white dolphins in Hong Kong waters has been decreasing, according to the latest official statistics, suggesting that government efforts to preserve the endangered species appear to be making little headway.
According to the 2016/17 Marine Mammals Monitoring Report published by the Agriculture, Fisheries and Conservation Department (AFCD), there were only 47 sightings of Chinese white dolphins in the waters off Lantau, where they tend to appear most often.
The number represented a 27 percent drop from the previous year and the lowest since 2002. There were no sightings for the second year in a row in the northeast waters of Lantau, where the main construction work for the Hong Kong-Zhuhai-Macau Bridge is taking place
In 1997, the Chinese white dolphin was chosen as the mascot to mark Hong Kong’s return to Chinese rule. It is listed among the wild animals under Grade 1 conservation according to Chinese law.
To prepare the report on marine mammals, researchers conducted a total of 178 line-transect vessel surveys in 10 survey areas in Hong Kong waters between April 2016 and March 2017.
Of the 1,233 dolphins sighted during the 12-month period, including Chinese white dolphins, only 17 were unspotted juveniles.
These young calves comprised only 1.4 percent of the total, compared with nearly 8 percent in 2003, suggesting the population of dolphins may dwindle in the future.
Dr. Samuel Hung Ka-yiu, chairman of the Hong Kong Dolphin Conservation Society and lead writer of the AFCD report, said the construction of the Hong Kong-Zhuhai-Macau Bridge has had a great impact on the habitat of the Chinese white dolphin, according to hk01.com.
Construction of the planned third runway and the high-speed ferries that regularly pass the waters are further threats to the animals’ survival, Hung said.
To help preserve the dolphins, Hung urged the government to establish a large marine protected area in West Lantau waters.
“Habitat destruction from expanding reclamation work in Lantau waters and the hi-speed marine traffic in the area have increased the stress on the dolphin population,” the World Wide Fund for Nature (WWF) said. “The underwater noise generated inhibits their echolocation capability.”
These disturbances threaten the survival of the remaining dolphins in Hong Kong waters, said Samantha Lee, WWF-Hong Kong conservation manager for oceans.
WWF-Hong Kong urges the government to establish the West Lantau Marine Park as soon as possible to protect the remaining dolphin habitats.