How is caviar related to European arid regions?

Caviar is related to European arid regions through the production of sturgeon, the fish whose roe is used to make caviar. Sturgeon are primarily found in the Caspian and Black Seas, which border arid regions such as the steppes of Eastern Europe and Western Asia. The arid climate of these regions contributes to the unique ecosystem in which sturgeon thrive, making them a key source of caviar production in Europe.