The West Sea Barrage (Nampo Dam) dammed an 8-kilometre sea section. The swamps, puddles and salt fields in the reserve designated around the West Sea Barrage are good habitats of birds and so many birds are gathering there. A lot of grass is growing there and acacia, pine and other trees are growing on low hills.
More than 90 kinds of water birds are living in the reserve. In summer warbler, water hen, coot, water-cock and others multiply and heron, Egreta garzetta and others inhabit the reserve.
In winter different kinds of duck live and large flocks of whooper swans and black swans winter in not far waters. Besides, the reserve is a stopover of white-fronted geese, brent geese, ospreys and snipes and a habitat of many migratory birds such as white-tailed and white-winged sea eagles and golden eagles.