A wide variety of birds inhabit not only the vast expanse of the Tuman River estuary but also the coastal areas of Rason and islands off the sea.
The areas of large and small bays of the East Sea of Korea, including Rajin and Josan bays, about with fish, shellfish, shrimp, sea urchin and other aquatic resources, making islands in this region an ideal place for sea birds to live and breed.
Al Islet off Uam-ri in the Sonbong area in particular is so populated by tens of thousands of sea birds, including black-tailed gull, Temminck’s Cormorant and guillemot, that its rocks and cliffs are covered with their nests.
Over 290 Temminck’s Cormorant with mother birds and juveniles were observed in July 2016.
In May and June, a breeding season of the sea birds, the islet is shrouded by scores of kinds of them which build their nests to lay eggs and sit on them. Al (egg in English), the name of the islet, was derived from this fact.
It has been widely known as an islet for birds and thus designated as a sea bird reserve.
Sea in the waters off Uam is a famous habitat of spotted and northern fur seals.
Northern fur seals are seen in large flocks in the sea off the Uam area and on islets in the East Sea of Korea as they move to their breeding places in the North Pacific Ocean in spring.
There are also a lot of spotted seals in this area.
Seals spending leisure time in the sea and on islets constitute one of conspicuous features in the scenery of the area.
The sea off Uam is a seal reserve.
The ecosystem in the Rason area is getting more diversified and abundant thanks to the consistent policy of the state on protecting the ecological environment.