Possible ecology hazards

What may happen to the ecology once the bridge is built

by Lam Kiu-wai, Q

"Twenty kilometers of coastline were destroyed when the Government built the Airport, North Lantau Highway, and Tung Chung New Town. At the time, they promised not to touch the rest of the [northern Lantau] coastline."

- Fabian Pedrazzini

The Pearl River Delta (PRD) region, with a sub-tropical climate, is rich in natural recourses and bio diversity. However, population growth, industrialization and urbanization in the region during the past two decades have contributed to the degradation of the region's ecosystems and environment.

The proposed construction of the bridge across the Pearl River Estuary posts yet another serious threat to the region's environment.

Air Quality

A 1996 case study* by the Hong Kong Polytechnic University says that ozone concentrations are higher at Lantau Island than at urban areas and eastern part of Hong Kong. The elevated ozone level is closely associated with the unique wind pattern on the western side of Hong Kong. Winds from the north and east transport photochemically "aged" urban plumes there from the Hong Kong-Shenzhen metropolitan area or from inland regions upstream of the Pearl River.

Once the bridge is built, it will bring in more cars to the area. The increased traffic will have a profound impact on the region's air quality which is already in trouble, says Fabian Pedrazzini of the Green Lantau Association.

*The chemical evolution and transport of ozone plumes in Hong Kong. T. Wang, Y.Y. Wu, Vincent T.F. Cheung and K.S. Lam; Regional Air Monitoring & Research Group, Department of Civil and Structural Engineering, The Hong Kong Polytechnic University

Water Quality and Marine Ecology


Sha Chau & Lung Kwu Chau Marine Park location and distribution of Chinese White dolphins in the Pearl River Delta region.

Since the detailed design and location of the bridge is yet to be confirmed, it is hard to estimate the possible effect on the water quality in the region. However, the bridge may have an impact on the instantaneous tidal flows and salinity patterns in the vicinity of the bridge. The possible reduction in tidal discharges across the line of the bridge may cause sediment build-up at the mouth of the Pearl River Estuary. It may also have an adverse impact on the already "under stress" Deep Bay and the Sha Chau and Lung Kwu Chau Marine Park.

Hong Kong's Mascot

Indo-Pacific Humpback dolphins, or better known locally as the Chinese White Dolphin or "pink" dolphin, is part of a global population known as Sousa chinensis. They live around shallow, coastal areas of the Atlantic, India and South Pacific Oceans and tropical seas of Southeast Asia. The population in the Pearl River Delta is unique because the calves are born gray and turn white or pink as they mature.

As the number of the animal decreases throughout Asia, the population in Hong Kong is now the only remaining, robust population in the region. However, it is feared that this resilient population will be unable to survive further worsening of the marine environment in the region due to increased human activities in the Pearl River Delta region.

Dredging and dumping during construction is one main concern. High levels of suspended solids around the reclamation, dredging and dumping sites will affect the ability of fish to breathe and choke them to death. Reclamation works will also bury and kill off any living organisms on the seabed.

The shallow, sheltered, estuarine waters of the PRD, in particular northern Lantau, is the feeding and resting ground for Chinese white dolphin or "pink" dolphin (see box). Any construction work will disturb the habitat of this rare marine mammal species, and the increase in boat traffic during construction may pose a threat to the dolphins too.

Terrestrial Ecology

Lantau has special ecological value with a diverse bio-network which includes mangroves, seagrass beds, and shrublands. It is home to some rare plant and animal species, like the Crested Kingfisher (Ceryle lugubris) at Yi O, the native Champion's Rhododendron (Rhododendron championae) from the peak to the seashore stretching from the slopes of Sha Lo Wan southwest to Tai O, and the tiny Romer's Tree Frog (Philautus romeri) which is found only in Hong Kong.

The proposed plan means massive development to the fishing village of Tai O and northern coast of Lantau. "Twenty kilometers of coastline were destroyed when the government built the airport, North Lantau Highway, and Tung Chung New Town. At the time, they promised not to touch the rest of the [northern Lantau] coastline," says Pedrazzini.

He says that if the bridge is to land in Tai O, the government will have to build a road connecting the landing site with the North Lantau Highway. The construction will undoubtedly destroy the rich coastal habitats and impose a serious impact on the ecosystems of the Lantau North Country Park and the wetland areas in Tai O.

#A Conservation Strategy For Lantau, July 1998. Green Lantau Association, the Conservancy Association, Friends of the Earth, Green Power, Hong Kong Marine Conservation Society, World Wide Fund for Nature HK.