State natural reserve "Sea-Yu" is located in the Murmansk region Nenets Autonomous district. The creation of the sanctuary took place on 1 November 1999 in accordance with the order of administration of the NAO. The objective of the reserve was not only preservation, but also a detailed study of the fauna and flora of the Bolshezemelskaya tundra and spruce relict woodlands and unique archaeological sites. The total area of the reserve is 54, 765 hectares, without isolation of the protected area.

One of the main attractions of the natural reserve "Sea-u" was the largest island relict spruce forest, located beyond the Arctic circle on the territory of the tundra.

Species characterized by social and economic significance, are breeding bean geese, which are characterized by an unusually high density. In addition, the reserve carries great scientific importance as a model facility intended for the monitoring of the dynamics and status of forest and tundra ecosystems due to the coming climate change.

With regard to historical cultural sites, plays an important role Chabadabada or sinful and Holy forest – forest island, Nenets has the title of Holy.

Important ecosystems and landscapes are the main value of the state natural reserve "Sea-u". Island relict spruce forest is located in the tundra zone and somewhat isolated from the predominant habitat of the Siberian spruce is formed in the sub-boreal period of the so-called Holocene, which refers to the more than 4, 5 thousand years ago. Forest plot character has a long and largely prevails in the valley of the river Sea-Yu. In the direction from East to West forest has a length of about 12 km, from North to South – about 2, 5 km. The growth of spruce trees in this area are carried out in separate groups and characterized by a greater prevalence in warm slopes of the shores of the new and the old river channel. Existing forest island carries a unique interest in the issue of studying and formation fauna as well as the phenomenon of the existence of a small fragment of dark coniferous taiga outside of the range.

The natural diversity of flora and fauna of the refuge is not yet sufficiently studied and on this issue there is insufficient material. Today within the distribution reserve discovered 246 species of plants found in the Sea area of the island-Yu

Very diverse presents the avifauna, which has about 60 species of birds. It is established that in the spruce woodlands bred nest about 12 varieties of the Siberian taiga ornithological complex: 1 species: Arctic – 2 views – European deciduous forests. For the territory of the reserve is characterized by high population and a great variety of geese, swans, waders and some other waterfowl, and upland Buzzard, Merlin and several predators.

In the lists of the red book included a large number of representatives that live in the reserve. For example, it contains 14 species of lichens, which are blackish, architecrure, rough Cladonia harsh, hypogymnia trichoid Bryoria, rising fascia and others. As for vascular plants in the Red data book listed: blunt the plant, two-coloured sedge, rotate lomatogonium, Alpine Zyryanka, blackish skarda and some other species.

Under special protection in the area of distribution of reserve "Sea-u" are: the lesser white-fronted goose, ordinary grey Shrike, Golden eagle, Bewick's Swan, peregrine Falcon, white-tailed eagle, grouse and Merlin. In total, under guard 39 representatives of flora and fauna, of which 29 species are protected in the mode of state control.

The reserve "Sea-u" is strictly prohibited the allotment of land and plots for construction, erection of structures and buildings, laying of roads and all types of communications, storage and use of pesticides and fertilizers, and mining and exploration activities.