February 2nd marks World Wetlands Day, and this year it's taking on special meaning. Poyang Lake, located in eastern China's Jiangxi province, used to get all the attention on this day with its remarkable ecological diversity.

The area is an important habitat for one of the largest concentrations of migratory birds in East Asia. It's also home to the world's only freshwater porpoise. But, as our reporter Wu Haojun finds out, all of this is now under threat.

China's largest freshwater lake no more. Poyang Lake once had a surface area of 3,500 square kilometers. And now this is all that's left.

Ge Gang, Professor of Wetlands Studies, Nanchang Univ., said, "When there's ample rainfall, the whole area's covered by water. Boats can sail through. But during such periods of drought, all this land emerges."

Once a favourite habitat for migratory birds, animals might now have to look elsewhere.

Jiangxi province has endured a prolonged drought that started last year. In September, water levels in Poyang Lake had fallen to less than 12 meters, as the drought period started 4 months earlier than normal.

Pan Hanming, Jiangxi Water Bureau, said, "Since 2003, water levels at Poyang have been about one to two grades lower than previous years. This indicates that the drought situation is getting more severe."

Professor Ge has conducted research on Poyang Lake for many years. He sees every day how the drought has impacted the area.

Ge said, "It used to be that vegetation here is about 70 centimeters tall. Sometimes it can be as tall as a person. But because of the drought, water covers the land for only 1 month a year. It used to be at least 3 to 4 months."

While animals who depend on the land may feel the pinch when it comes to food, for local residents, it's lost business.

According to the local bureau of fisheries and aquatic resources, the prolonged drought has reduced fish stocks by more than 60 percent.

Xiong Haibing, local resident, said, "I remember in the past, when there was a strong wind, the waves would carry fish on shore. All the villagers needed to do was pick them up."

Amid all the signs of distress at Poyang Lake, migratory birds seem to be the only stable factor. According to an investigation at the end of last year, migratory birds still numbered about 50,000. But whether they'll choose to stay as the drought lingers on, is still an open question.

China's Poyang Lake in distress