When the comb jelly, mnemiopsis leidyi, was accidentally introduced into the black sea, what eventually happened to the black sea ecosystem?

With growing worldwide interest in the oil and gas
reserves of the Caspian region, the ecological prob-lems of the area are also receiving increased attention.Due to its position in the far southeast of Europe, littleinformation about the region was available in the Westuntil recently, and it was not until a few years ago thatthe public became aware of the potential disasterthreatening the unique ecosystem of the Caspian Seaand its immediate surroundings (Dumont 1995). Stone(2002) described most of the acute problems in thisarea: reduction of the river run-off reaching theCaspian Sea caused by damming the main tributary,the Volga river; the unstable water level; the varioussources of pollution; the over-utilisation of its livingresources (in particular the sturgeon species); and,finally, the threat to the entire system posed by a newinvader, the ctenophore Mnemiopsis leidyi.