Stemming the Tide

Killer technologies target invading stowaways

Zebra mussels. Green crabs. Sea lampreys. Ruffe and round gobies. These are just a few of the troubles that have swum forth from the bellies of oceangoing ships. Those species and scores of other once-foreign aquatic organisms now besiege U.S. ports and waterways. These unwanted immigrants have found passage to the New World by stowing away in ships’ ballast tanks, each a potential Pandora’s box of ecological perils.