The loss of marine habitat to a new airport runway will probably displace the population of Chinese white dolphins from north Lantau - but they will come back eventually, airport officials and their consultants say.
The main draw would be a new 2,400-hectare marine park connecting the existing Sha Chau and Lung Kwu Chau Marine Park with a planned Brothers Islands marine park.
The plans were confirmed in the Airport Authority's environmental impact assessment for a third runway, released yesterday.
However, the report drew scorn from one dolphin conservationist, who described it as contradictory.
One of the airport's consultants, Dr Thomas Jefferson, told a media briefing yesterday that some decrease in dolphins was to be expected during construction. "But the plan and hope is that the large marine park will provide an attractive habitat for the dolphins to move back to," he said.
Jefferson noted that dolphin numbers declined when the airport at Chek Lap Kok was built in the 1990s but quickly rebounded after the Sha Chau marine park was designated. No projection was made in the report as to where the dolphins would go while the runway was being built.
"Dolphins are very complex animals … they have the ability to move around," Jefferson said.
Dolphin Conservation Society chairman Dr Samuel Hung Ka-yiu dismissed the report as "contradictory".
"Imagine someone goes to your home, destroys it completely, and then tells you, 'Don't worry it will be fine in seven years', and where you go in the seven years is not their problem," he said. "Where is the logic in this?"
The report also concluded that the project would result in no adverse residual impact on air quality. But green groups said it was "flawed" and "selective".
The report, for instance, claims the project would deliver better air to Tung Chung in the form of reduced ozone pollution. It explained that simulations showed nitric oxides emitted from the airport could consume the ozone.
"They are just playing a game of numbers," Friends of the Earth officer Melonie Chau Yuet-cheung said.
The authority says nitrogen oxide emissions are forecast to increase 53 per cent to 9,500 tonnes from 2011 to 2031. But fine particles will be cut by 40 per cent as pollution reduction technology improves.
Watch: SCMP took a look at Hong Kong's pink dolphin habitat