Researcher warns that development projects increasingly pose threat to mammals' habitats
The government should expand marine parks and scrap the idea of building a third airport runway if the Chinese white dolphin's diminishing habitat is to be protected, a leading dolphin researcher says.
The advice came after six years of research into the distribution and habitat of dolphins within Hong Kong waters, which will offer infrastructure planners a better idea about the location of no-go areas.
These include waters from Tai O to Fan Lau, Lung Kwu Chau and Sha Chau Marine Park, and Sham Shui Kok near The Brothers islands, where the highest densities of dolphins were recorded during the research.
Dolphins favoured these sites because they experienced less disturbance there by humans, better environment and richer food supplies.
To preserve these sites better, they should be designated as quickly as possible as marine parks or reserves with enhanced management measures such as closed areas for sea traffic, before they were destroyed by new development, said the report by Samuel Hung Ka-yiu, who did the research for his doctorate at the University of Hong Kong.
According to the research, about 200 to 220 white dolphins were regularly found within Hong Kong waters over the past decade, part of a 1,300-strong population living in the Pearl River estuary.
This group of resident dolphins probably survived construction of Chek Lap Kok airport in the 1990s, which left them a much smaller habitat in the waters of north Lantau because of massive reclamation.
'I will not say they are doing well,' Mr Hung said. 'They are just doing OK and surviving.'
He warned that further environmental degradation might seriously disrupt the sustainability of the species or push them out of Hong Kong waters, especially in light of the large infrastructure developments planned for Lantau.
Among the projects planned in the area is the Hong Kong-Zhuhai- Macau Bridge, to run from 100 hectares of reclaimed land northeast of the airport, the Chek Lap Kok-Tuen Mun link, a logistics park and a new town development set for Tung Chung.
'The proposed third runway will also have huge impact.'
While it remained uncertain when these projects would start and the amount of land reclamation involved, Mr Hung said it was the government's responsibility to assess their effects and formulate clear guidelines.
He suggested that habitat loss from these projects could be compensated for by setting up new reserves or marine parks 10 times the size of lost areas.
Mr Hung said increasing vessel traffic off Lantau, marine pollution and even dolphin-watching activities also posed immediate and long-term threats to dolphins.
Over the past decade, about eight to 10 dolphins have been found dead each year and researchers have reported that fewer calves have been seen in Tai O, a dolphin-sighting hot spot, in recent years.
A spokesman for the Agriculture, Fisheries and Conservation Department said all designated works projects must undergo environmental impact assessment that might require mitigation measures during and after construction.
He said the department would continue with plans to designate the Sokos islands and southwest Lantau waters as marine parks.