There are vast oil reserves under the Caspian and swimming in its waters are giant caviar-bearing beluga sturgeon.

There are vast oil reserves under the Caspian and swimming in its waters are giant caviar-bearing beluga sturgeon. Both riches have been the subject of disputes between the nations that claim a share of the Caspian and some of these disagreements centre on just how one defines these waters - as international ocean waters or inland sea or lake?