Our Bay: Ballast invaders

BALTIMORE - A key battle in the war against invasive species is being waged in the bowels of a 700-foot freighter docked in the Middle Branch of the Patapsco River in south Baltimore.

Far below the deck, Dr. Mario Tamburri oversees a team of scientists testing a private company's device that's supposed to kill critters in the ballast water of the MV Cape Washington. The hope is that this system - or some other system - can kill invasive critters that stow away on ships that circle the globe.

Large ships like the MV Cape Washington draw up water to hold in special tanks to keep balanced while at sea. The trouble is that...