Kazakhstan’s Wetlands in the northern part of the Caspian Sea are crucial to preservation of the population of migrating waterfowl. Birds from the vast areas with Eurasia temperate climate migrate via Kazakhstan to wintering areas in the South Asia and Africa frequently with long-term stopovers for resting, molting and fattening. Twice a year over 280 migrating birds, including rare and endemic species, find a shelter here. Extensive reed beds serve as a shelter for nesting birds. Mute swans and many ducks use reed beds as a place for molting.
The whole eastern coast of the Caspian Sea is covered with reeds. The width of the reed belt in the Ural River coastal area ranges from 5 to 18 km. The reed belt plays multiple roles. It serves as a natural barrier against tidal surges and slows down the rate of water level rise. At the same time, the reed belt is a filter trapping to a great extent pollutants washed off the coast. Reed belt is a habitat for various fish and bird communities. Vegetation and invertebrates inhabiting it serve as a food stock both for migrating and nesting birds.
The Caspian Sea belongs to partially freezing seas with its shallow northern part freezing every year. Ice season in the North Caspian Sea lasts from November through March. The North-Eastern Caspian Sea is the area with a 100% probability of ice formation during the cold season of the year. The sea starts freezing in the north-east and then ice expands to the south. Ice along the sea coast forms quicker than in the open deeper part of the sea. The ice thickness reaches its maximum (75-96 cm) in the middle of February, and then it remains almost the same till the start of melting. The ice clearing process in the sea occurs in the reverse direction.