States would have new help — and new responsibilities — in the fight against foreign aquatic species under bills introduced Wednesday in Congress.

The National Aquatic Invasive Species Act of 2003 would require that states have plans for dealing with foreign species like the northern snakeheads found in a Crofton, Md., pond last summer and the zebra mussels discovered recently in Virginia.

The bills would also authorize $170 million a year to fight the pests and require that live aquatic organisms be screened before being imported — a provision that one sponsor said would apply to the Virginia Seafood Council's plan to test 1 million Asian oysters in the Chesapeake Bay.

"If someone wants to introduce a nonnative species, this screening process will try to determine if the species will be invasive or if it can live in its new environment in harmony with the other life forms," said Rep. Wayne Gilchrest, R-Md., a sponsor of the two House bills.

A companion bill was introduced Wednesday in the Senate.

Economic losses and the cost of fighting aquatic species are estimated at $137 billion a year, according to a report last year by the General Accounting Office.

Similar legislation died last year when Congress adjourned. But Gilchrest's legislative director, Jeri Finke, said supporters hope for action within 100 days on the latest bills, which have more than 60 co-sponsors in the House and no major opposition.

"By and large, we have no objections to the bill," said Cynthia Brown, president of the American Shipbuilding Association.

Foreign aquatic species are most often transported to new destinations in the ballast water of seagoing ships, which is carried in the holds of ships for stability. Among other things, the legislation would require that by 2011 ships begin treating this water before discharging it in foreign waters.

Such technology could cost millions to test and then more than $250,000 to install on each vessel, industry officials said. The ultimate cost will not be known until the government decides how clean it will require the discharge to be.

"There's too much hanging out there right now," said Kathy Metcalf, a spokeswoman for the Chamber of Shipping of America.

Metcalf also noted that, after 10 years of work, the United Nations' International Maritime Organization is getting close to passing its own requirements for ballast water.

"The international treaty and the U.S. regulations, in an ideal world, would be the same, but that won't happen," Metcalf said, adding that the U.S. rules "will be stricter, but livable."

Finke said requirements within the act will be used by U.S. representatives working with the international body.

Maryland also is working on its own invasive species legislation, including a bill that would allow state agencies access to personal property to investigate and eradicate the invasive species.