THE jellyfish-like predator that wrecked fisheries in the Black Sea has now
invaded the Caspian, where it threatens to do even more harm.
The comb jelly Mnemiopsis leidyi reached the Caspian in 1999,
probably by stowing away in the ballast water of ships from the Black Sea, which
is linked to the Caspian by a canal. It is proliferating even faster than it did
in the Black Sea, Henri Dumont of Ghent University in Belgium and his colleagues
report in a forthcoming issue of The Journal of Biological Invasions.
The comb jelly not only eats the zooplankton on which many fish feed, it also
gobbles up fish eggs and fry. Dumont says local fisheries will collapse within
two or three years if nothing is done. He thinks this could also lead to the
extinction of the Caspian seal, Phoca caspica.
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Comb-eating predators鈥攕uch as milkfish or another comb jelly, Beroe
ovata鈥攕hould be introduced as soon as possible, the researchers say.
鈥淭here鈥檚 almost no time,鈥� says Dumont. 鈥淚鈥檓 terrified.鈥�