Black Sea Threatened
With New Jellyfish
Creatures' Mass: A Billion Tons
Source: The Detroit Free Press
CONSTANTA, Romania (AP) -- The intruder arrived sometime in 1982.
It rode from the Atlantic in the ballast water of a cargo ship and was flushed into the Black Sea, experts believe.
Then it began to eat and multiply at a frightening rate -- a fist-sized wrecking ball.
By 1990, the total mass in the Black Sea of all the jellyfish-like creatures, known as Mnemiopsis leidyi, was estimated at 1 billion tons -- equal to the total wet weight of all the fish caught in the world that year.
The tale of mnemiopsis -- pronounced ne-me-op-sis -- reflects the devastation that a single alien species can cause in an almost closed ecosystem like the Black Sea.
Free from its predators in the western Atlantic, the animal devoured fish larvae, eggs and the plankton needed by small fish. Anchovies and the Azov Sea kilka, two commercially important fish, were among the hardest hit.
Mnemiopsis, a hermaphrodite that is able to reproduce independently, has declined a bit in the Black Sea. Scientists are not entirely sure why.
``What is certain, though, is that mnemiopsis altered the Black Sea as perhaps no other alien species ever had anywhere,'' said Richard Harbison, a biologist at the Woods Hole Oceanographic Institute in Massachusetts.
Harbison's proposal: Maybe another voracious alien could come to the rescue.
Harbison has been studying the possible introduction of the butterfish to attack the Black Sea mnemiopsis. The fish, which averages about 5 1/4 ounces and lives off the coast of North America, can eat its weight in jellyfish every hour.
But he said ``many more experiments'' are needed to see if the fish can reproduce in the Black Sea.
There is also the biological risk.
``The intentional introduction of yet another exotic species into the Black Sea poses serious ethical questions,'' Harbison told marine researchers during a recent tour of the sea. ``We must face the possibility that something could go terribly wrong.''

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