Caspian Sea threatened by new predator

Scientists in Russia say the ecology of the Caspian Sea in Central Asia is under serious threat from a new predator -- a large jellyfish-like animal.

The Director of the Caspian Fishery Research Institute, Vladimir Ivanov, said the creatures -- known as Mnemiopsis -- were destroying flora in the Sea which sturgeon and other wildlife eat.

He told the Russian news agency Itar-TASS that the numbers of sturgeon, the source of caviar, had already been dramatically reduced. He said the creatures had first been sighted off the coasts of Turkmenistan and Kazakhstan last year, but have since appeared off the shores of Dagestan and in the northern Caspian. It's thought they were introduced to the Caspian in the ballast tanks of ocean-going ships plying the Volga River.

From the newsroom of the BBC World Service