Shrinking Shenzhen mangrove forests poses threat to migratory birds

The reduction in a large area of wetlands poses a threat to the many migratory birds that visit the nearby Mai Po Nature Reserve, experts say

PUBLISHED : Wednesday, 28 November, 2012, 12:00am
UPDATED : Wednesday, 28 November, 2012, 4:04am

The dramatic shrinking of Shenzhen's mangrove forests over the past three decades poses a threat to the many migratory birds that visit Hong Kong's Mai Po Nature Reserve each autumn, winter and spring, experts in both cities warn.

Shenzhen had more than 530 hectares of mangrove forest in the early 1980s, forming one of China's most important wetland conservation zones. It now has less than a quarter of that left - just 130 hectares - experts said in a report published in Shenzhen's Daily Sunshine newspaper.

More than half of the endangered species that were living in Shenzhen's mangrove wetlands have disappeared, including birds, plants and fish, the report said.

It said shorebirds had suffered the most. In the early 1990s, more than 70,000 birds lived in the wetlands between Shenzhen's Futian and Nanshan districts. Today, less than a third remain.

The mangrove wetlands straddling Shenzhen and the Mai Po Nature Reserve are considered an important habitat for nearly 200 bird species, especially migratory ones that use the East Asian-Australasian Flyway every year to travel to and from breeding grounds in northern China, Mongolia and Siberia.

"The size of Shenzhen's mangroves is shrinking drastically and is now less than 130 hectares, according to an ongoing survey that I and other NGOs are doing," Wang Yongjun, a former head of Shenzhen's Futian Mangrove Nature Reserve, told the Daily Sunshine in the report published last month.

Xu Meng, director of the Shenzhen Bird Watching Society, said the extent of the mangrove forests and the number of rare bird species seen had been dropping every year.

"For example, the last time that someone reported seeing Pelecanus crispus [Dalmatian pelican] - a beautiful, big, white aquatic bird - was the spring of 2003," Xu said. "Since then, it's disappeared from the skies of our city."

Experts in Shenzhen blamed the mangrove forests' decline on reckless urbanisation and industrial pollution. But few expected such a massive loss of forest area, especially after Shenzhen's city government released a blueprint in 2007 pledging to triple the size of the city's mangrove forests to more than 500 hectares by 2015.

The authorities have not released a general survey of the state of the city's wetlands and mangroves since 2006.

Most of Shenzhen's remaining mangroves are now threatened by infrastructure projects and commercial property development.

The mangroves of the Dapeng subdistrict in east Shenzhen are being nibbled away by the government-supported Shenzhen Strategic Emerging Industry base.

Those in the Xixiang, Fuyong and Shajing subdistricts in west Shenzhen are making way for two state-run projects - China's second West-East Gas Pipeline and the Guangzhou-Shenzhen Coastal Expressway, which is expected to open next year and reroute a third of the vehicles using the existing Guangzhou-Shenzhen Expressway.

Xiong Yang, from the Green River NGO, who has been studying Shenzhen's mangrove forests for years, said the Nanshan district's Qiaocheng wetland, upstream of the Mai Po marshes, was under threat from property projects.

"The wetland park in Overseas Chinese Town's Happy Coast, a commercial reclamation project in the Qiaocheng wetlands, is actually becoming a new threat to the nearby Mai Po reserve, even though the developers and authorities have hailed the project's new villas, artificial lake and yacht docks as a haven to protect birds," Xiong said.

"To make the wetland park attractive for property buyers and tourists, the developers are trying to launch projects to clean up the wetland's silt and also introduce seawater to clean up the wetland. It will make the park look beautiful and clean but will be a disaster for the fragile ecosystem.

"I have been writing letters to ask government to release information about the projects. It's very ironic that the municipal Human Settlements and Environment Commission asked me to approach the developers."

Repeated calls to Futian mangrove reserve authorities went unanswered.

A spokesman for the Happy Coast project said the local government had praised the project as a "successful, eco-friendly business model."

"It was severely polluted and just wasteland seven years ago before we spent huge sums to reclaim land there. Now, the wetlands there look much more beautiful and have recovered after we cleaned up waste and overgrown vegetation," he said.

Dr Wen Xianji, a mangrove specialist at the global conservation body WWF, which manages the Mai Po Nature Reserve, said he was concerned about the commercial projects.

"The authorities should be very careful when approving such projects. They might change the salinity of the coastal-estuarine wetland," he said. "It would be a big blow to species that have been living there for centuries.

"I don't know if the Hong Kong government has been informed about this plan or not. But I do know that WWF knows little about it, even though any change on the Shenzhen side would affect the general environment in Deep Bay. Although the size of the mangrove forest on the Hong Kong side has expanded in recent years, various infrastructure projects and water pollution across the Pearl River Delta are continuing to affect the Hong Kong side."