The first large freshwater lake in Gannan is an important wetland in the eastern part of the Qinghai-Tibet Plateau, known as a pearl on the plateau, and was named a provincial migratory bird nature reserve in 1982. The area where Bohai Lake is located, Tibetans call it "Cuoning" is "the place where yak walks around". Bohai Lake has lush water grass, and many rare birds that migrate south and north have settled and reproduced here. Black-necked cranes, gray cranes, swans and other rare birds are scattered on the grass beaches by the lake.