Chinese black carp vs. zebra mussel.

A plan to use. imported mollusk-eating black carp from Asia to help solve North America's zebra mussel crisis is risky and lacks scientific basis, according to Ohio State University researchers. "Our experiments with exotic species have usually been failures. If black carp are introduced, we could be opening the ecosystem up to a whole host of risks," warns associate professor of zoology David A. Culver, who has been conducting research on zebra mussels since 1988. "Furthermore, we don't even know for sure that black carp will eat zebra mussels in a foreign environment."

Four fish farms in the southern U.S. have imported black carp from China and Taiwan and two have spawned the fish artificially. Next, the farms' aquaculturists will attempt to produce specially engineered, sterile young. Once these sterile fish are mature, the aquaculturists hope to sell them to utility companies and cities for use in zebra mussel-infested industrial and public drinking water systems. Ideally, the black carp will feast on the pesky bivalves.

There are many potential problems with this plan, Culver maintains. Perhaps the most compelling argument is past experience. Time and again, scientists...