Globally, wetlands are among the most endangered ecosystems. Their value is not seen as marketable so it is tempting to eliminate them in order to provide spaces that more readily turn a profit. Wetlands furnish shelter for birds and many aquatic species that live in the open water. Populations of birds find vital refuges for their migration and reproduction. The exceptional primary productivity of wetlands provides abundant food for fish.
Reeds help purify water.
These few examples merely hint at the many functions of these ecosystems that are absolutely vital to the balance of fauna and flora, of hydrological resources and humans. This immense corridor, centered on the Volga delta, is unique in Europe. To over-simplify, it is an huge water treatment plant that covers more than 600 miles, and that can also shelter and feed diverse and numerous populations. Quite simply it is one of the main life-insurance policies for life in the Caspian Sea. Russia recognized this when, in 1919, it established its first national preserve in the Volga delta.