The U.S. House has approved a bill that would set a national policy for cleansing ship ballast water to kill invasive species while prohibiting states from imposing tougher requirements.
The measure that passed the Republican-controlled chamber Tuesday would adopt an international standard limiting the number of live organisms in ballast water. Vessel operators would have to install technology to comply.
The shipping industry says an existing patchwork of more than two dozen state and tribal policies is unworkable because vessels move constantly from one jurisdiction to another. New York rules scheduled to take effect in 2013 would be 100 times tougher than the House standards.
Environmentalists say the House measure isn't strong enough to prevent more invasive species from reaching the Great Lakes. They say they hope to derail it in the Democratic-controlled Senate.