Science in Iran - Attack of the killer jellies

A vicious alien is wreaking havoc in the Caspian Sea, but governments have notapproved deployment of the only weapon likely to stop it. The Caspian Sea hasbeen overrun by Mnemiopsis leidyi, when the Black sea was overrun the population was brought under control by the introduction of Beroe ovata. Beroe can survive in the brackish water of the Caspian but cannot breed. The sturgeon fishery has been hit by the jellyfish which has knock on effects to the Caspian Seal. No decision has been made about the introduction of Beroe to the Caspian but the sturgeon fisher has improved slightly.