BEIJING, June 18 (Xinhua) -- The expansion of sea reclamation and coastal aquaculture is the main cause of wetland degradation, according to the China Science Daily on Tuesday.

The China Geological Survey of Ministry of Natural Resources conducted investigation and research around Liaohe Delta wetland, Yellow River Delta wetland and Yancheng coastal wetland.

The coastal wetland, a transition zone between terrestrial and marine ecosystems, has an important ecological function. Abundant types of coastal wetland including estuaries, deltas, mud flats, salt marshes, mangroves, coral reefs and shallow waters are distributed along China's coastline, said the newspaper.

Constructing an ecological elements observation system covering water, land, atmosphere and biology, the researchers get the response mechanism between coastal wetland ecological and geological environment and climate change, sea level rise and human activities.

They also confirmed huge carbon storage ability of coastal wetlands.

Around Liaohe Delta wetland in northeast China, hydrological adjusting and micro geomorphic transformation increased the water area and vegetation, while water diversion canals were built to adjust water and sediment supply and improve biodiversity around the Yellow River Delta wetland.

The researchers also selected four reed genospecies worldwide with high resistance to salt and disease from 91 samples to apply in wetland restoration.