The number of sturgeons and their distribution on feeding grounds in the Caspian Sea were assessed. Data were collected between 1991 and 1996 on environmental factors, species composition, and population sizes in the Northem, Middle and Southern Caspian Sea except for Iranian waters. The results show a drastic decline of the sturgeon populations on the feeding grounds at sea. In order to preserve the Caspian Sea sturgeon populations, efforts of all States surrounding the Caspian Sea must be increased and harmonised to serve a single system of fishery management, stock conservation and enhancement measures based on natural reproduction and artificial propagation.