In "Silent Spring," the book that helped launch the environmental movement in the United States four decades ago, author Rachel Carson evokes a spring season in which birds had been killed by pesticide abuse and their songs could no longer be heard.

Now, the silent spring is not far away in many places in China, and birds are vanishing, not because of pesticides, but because their habitats are shrinking.

China's largest desert freshwater lake -- Hongjiannao, home of some 20 rare species of birds -- may dry up in a few decades, experts warned at an international seminar on wetland preservation in Shaanxi Province, northwest China, last month. The shrinking lake and the vanishing birds are the very epitome of the quandary that faces China nowadays: rapid economic growth at the expense of the natural environment.

Sandwiched between the Muus Desert in Shaanxi Province and the Erdos Plateau in north China's Inner Mongolia Autonomous Region, Hongjiannao has shrunk by at least 30 percent in the past two decades. Its lake area, which measured more than 6,600 hectares in the 1990s, has shrunk to 4,600 hectares, and its water level is declining by 20 centimeters a year, says the Xinhua news agency. The lake is about 8.2 meters deep on average.

Dams, industrial pollution and climate change are all threatening Hongjiannao. Dams have been built since 2006 on two of the seven rivers that flow into the lake, reducing water supplies to it.

Besides a shortage of water, Hongjiannao suffers from industrial pollution from coal-fired power plants and coal mines, the nearest less than 3 kilometers away, says Xinhua news agency.

In the face of pollution across China, Hongjiannao is not the only wetland that is weeping, though before long, it may have no tears to shed.

Poyang Lake in Jiangxi Province, the largest freshwater lake in China, has also been shrinking and is heavily polluted. Dongting Lake has shrunk 40 percent from 70 years ago. And 50 percent of China's coastal wetlands have disappeared since the 1950s, the online edition of People's Daily reported in 2003. Guangming Daily reported in February this year that 30 percent of the remaining wetlands in China today might be erased for "economic development."

People fear that more and more wetlands are likely to follow in the miserable footsteps of Lop Nur in Xinjiang Uygur Autonomous Region. It was the largest lake in northwestern China before it dried up in the 1970s as a result of desertification and environmental degradation, says Xinhua news agency.

Often referred to as the world's "kidney," wetlands include lakes, bogs and swamps, and are essential ecological features in any landscape. They reduce the impact of flooding, prevent soil erosion, balance ecological diversity and slow the onset of global warning.

China's wetland reaches some 65 million hectares, which ranks first in Asia and fourth in the world. Since the 1980s, the Chinese government has come to understand the importance of wetland preservation and has built wetland natural reserves.

Then why are wetlands still diminishing? One reason could be a lack of coordination among local governments as such a huge lake as Hongjiannao often extends across many regions.

As for the law, China does have a number of laws which touch on wetland and resource protection. However, laws are useless if local governments and investors bend them in their blind pursuit of growth and profits.

(Shanghai Daily August 6, 2009)