A unique valley network of river floodplains, islands, lakes and temporary water bodies (or "sors"), and an extended pseudodelta. Habitats include sedge-willow fens, associations of "sor" vegetation, swamp and peat meadows, shrubs and willows. The site, one of the richest waterbird habitat and nesting areas in the world, supports up to 500,000 waterbirds during migration. The site supports internationally important numbers of breeding and molting waterbirds, especially ducks and swans, and several threatened species. The wetlands provide important feeding areas for sturgeon and whitefish and support a rich mammal population. Human activities include cattle-grazing and haymaking, commercial fishing, fur trapping, timber harvesting, and conservation education.