But in 2001 a scarcity of Caspian sea sturgeon forced caviar lovers to find other sources, and suddenly Sunburst was selling to dozens of high-end restaurants in New York.

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DC, which has been campaigning for several years for greater protection for sturgeon in the Caspian Sea a body of water that is the source of about 90% of the trade in caviar.

ECONOMIST: Fishing (II): Conserving caviar | The

As well as announcing the doctorate and the companies vying for the Saltire Prize, Ms Sturgeon also launched a junior Saltire Prize photography competition called The Power of the Sea, with renowned Scots photographer David Eustace among the judges.

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Sea turtles, elephant seals and many other fish, including eels, tuna and sturgeon, have a similar migratory strategy, he added.

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