Advisory council casts doubt on Hong Kong Airport Authority’s claim of minimum impact on dolphins from ferry diversion
Experts find data not solid enough, and urge more proof on next meeting
Environmental advisers have cast doubt on the Hong Kong Airport Authority’s claim that a rerouting of its high-speed ferry service had a minimum impact on the endangered Chinese white dolphin’s use of a key marine habitat.
In a presentation to the council of a 12-month monitoring study on the effectiveness of the plan on Monday, Airport Authority consultant Dr Thomas Jefferson said: “We haven’t seen any evidence of a decline in dolphin use in the speed control zone.”
He was referring to a management plan implemented in December 2015 to divert all Zhuhai and Macau-bound ferries north and northwest from Lantau Island and through a narrow corridor between north Sha Chau and Lung Kwu Chau Marine Park and the Urmston Road anchorage area.
Council members at the time had expressed concerns that the diversion would be worse as the new route cut through a core dolphin habitat.
The original route was a corridor between the south of the marine park and the airport.
A cap of 99 was also placed on the average number of ferries, with a 15-knot speed limit enforced in a zone within the passage.
But council members at Monday’s presentation were not convinced.
Dr Billy Hau Chi-hang said he was unable to see any conclusive correlation between occurrences of high-speed ferries and dolphin presence in the speed control zone.
“You can’t make this conclusion based on the data and say there is no impact on the dolphins,” he said.
Jefferson had said: “All the data that we have suggests… that the area around the marine park and in particular, around Lung Kwu Chau, as in the past, remains an area that dolphins use, especially for foraging.”
The survey results found that the total estimate of the dolphin population in Lantau’s west, southwest, northwest and northeast waters was 63, which was similar to the government’s tally in 2015.
Professor Nora Tam Fung-yee questioned the authority’s premise given that rerouted high-speed ferries only made up 5 per cent of the marine traffic through the corridor.
“You didn’t take into account the fact that the other 95 per cent [of traffic] was beyond your control,” she said.
Council chairman Stanley Wong Yuen-fai urged the authority to return with more solid proof in the next meeting.
Authority executive director Kevin Poole said they would do their best to fine-tune the data.
An Agriculture, Fisheries and Conservation Department report – conducted between April 2015 and March 2016 – estimated that the total number of white dolphins in Hong Kong waters had dropped by a quarter from 87 to 65.
