XINING, Sept. 24 (Xinhua) -- Qinghai Lake, China's largest inland saltwater lake, has seen an increasing number of migratory water birds, according to nature reserve authorities.

During the migratory bird monitoring and patrol operations conducted from Sept. 16 to 21, the monitoring staff spotted 39 species of water birds totaling over 233,000 in number, increasing nearly 32 percent from the same period last year, said Sun Jianqing, an official with the Qinghai Lake National Nature Reserve Administration.

These birds included 60 black-necked cranes, a species under first-class national protection, and 27 whooper swans, a species under second-class national protection, Sun added.

"In recent years, with the continuous improvement of the ecological environment of Qinghai Lake, the number of water birds here has continued to increase," said Sun. "Years of standardized monitoring and patrol, as well as research work on the behavior and habits of the water birds, have enabled us to understand their migration pattern and better protect them."

Located in northwest China's Qinghai Province, Qinghai Lake is an important ecological barrier in northern China and a key stopover site for migrant birds.