The U.S. Fish and Wildlife Service decided to remove the gray wolf from the list in March, saying the species had recovered from near-extermination in the region. That transferred wolf management to Idaho, Wyoming and Montana, which are planning what would be the first public hunts in decades.

The lawsuit filed last week by 12 environmental and animal rights groups seeks to block the hunts, but the three states that filed paperwork with the court Monday and Tuesday hope to fend off the litigation so the hunts can proceed.

Officials from the states said Tuesday that they can be trusted to sustain wolves without federal oversight. The hunts, they said, are needed in part to control wolf packs that have been killing an increasing number of livestock.

"People have supported wolf recovery on the belief that being successful would mean a return of state authority over the animal," said Bob Lane, chief legal counsel for Montana Fish Wildlife and Parks.

At least 39 wolves already have been killed in the region since federal protection was lifted. Those deaths came under more relaxed rules for ranchers responding to livestock conflicts and a shoot-on-site designation for the predator across most of Wyoming.

An estimated 1,500 wolves now roam the three states. Federal biologists say that is much more than needed to sustain the species, but critics say only a larger population could prevent inbreeding and offset the impact of hunting.

American anti-pollution campaigner Erin Brockovich has announced that at least two American law firms are prepared to pursue Alcoa in the United States on behalf of residents who live near its alumina refineries south of Perth, at Wagerup, Pinjarra and Kwinana.

The residents say their health has been adversely affected by emissions from the refineries. Simon Morrison from Shine Lawyers says the residents will not have to pay any money initially to join the claim.

"The US law firms involved in this claim do operate claims on what we call a contingent basis, which means no fee is payable to them unless the claim succeeds," he said.

"The next step for them is to obviously conduct some investigations of their own on the core issues surrounding the litigation.

"That would then follow what we call a forum application, in other words, bringing the matter in front of a judge in America, to test that issue of whether this is a case that can actually be brought in the United States."

Alcoa says any legal action will be vigorously defended.

The U.S. 9th Circuit Court of Appeals in San Francisco ruled that California's new regulation is preempted by federal law. The Clean Air Act allows California to set its own standards for various vehicles and engines if it receives waivers from the U.S. Environmental Protection Agency. The state argued that in this case it didn't technically need a waiver, but the judges disagreed.

Ships sailing into the ports of Long Beach and Los Angeles are considered a major source of particulates, nitrogen oxides and sulfur, pollutants that cause the region to frequently violate federal health standards.

Microscopic soot from diesel engines can lodge in lungs, triggering heart attacks, asthma and other cardiovascular and respiratory problems, scientists say. Diesel exhaust has also been linked to lung cancer.

The ruling is the second setback in two months to California's efforts to combat air pollution rather than wait for federal action.

For four decades, the state has adopted its own regulations for cars, trucks, factories, consumer products and other sources of air pollution, often prompting the federal government to set similar standards.

Microscopic soot from diesel engines can lodge in lungs, triggering heart attacks, asthma and other cardiovascular and respiratory problems, scientists say. Diesel exhaust has also been linked to lung cancer.

The ruling is the second setback in two months to California's efforts to combat air pollution rather than wait for federal action.

For four decades, the state has adopted its own regulations for cars, trucks, factories, consumer products and other sources of air pollution, often prompting the federal government to set similar standards.

A jury in Alaska said $5 billion. An appeals court said $2.5 billion. And Exxon's answer Wednesday was nothing at all, because the company said it already had paid plenty.

Justices explored just about every possible alternative through intense questioning during 1 ½ hours of arguments before a packed courtroom. By the end, it seemed several held the view that the company could be found liable for punitive damages, but perhaps not as much as even the appeals court had found.

There were several unusual aspects to Wednesday's arguments in a case that has bounced through the legal system for 14 years.

Justice Samuel Alito is recused because of his Exxon stockholdings, so even a 4-to-4 tie on the court would affirm the lower court's decisions that punitive damages are owed to nearly 33,000 fishermen, native Alaskans, businessmen and others consolidated into the single suit against Exxon.

And, as Justice David Souter noted, the court for a decade has struggled with determining whether punitive damages awarded by state courts were excessive. Now, he suggested, it is the Supreme Court's turn to "come up with a number."

Exxon has acknowledged that the captain of the Exxon Valdez, Joseph Hazelwood, was drunk at the time of the March 24, 1989, accident, and the corporation has paid about $3.4 billion in fines, compensation and cleanup costs.

Maritime law has shielded ship owners from being punished for damage caused by their vessels. This made sense during the era of sailing ships, Souter said. "In those days, when a ship put to sea, the ship was sort of a floating world by itself," he said.

Walter Dellinger, representing Exxon, cited this principle of maritime law and urged the court to throw out the entire punitive verdict. He cited the case of the Amiable Nancy in 1818 as having a historic precedent shielding ship owners.

But his argument quickly ran aground. "It's rather, I think, an exaggeration to call it a long line of settled decisions in maritime law," Justice Ruth Bader Ginsburg said.

As a fallback, Dellinger argued that the $2.5 billion verdict was too high. He cited several federal laws that, for example, fine those who pollute the environment. Typically, these legal fines may total millions of dollars but not billions, he said.

But mostly, people in Cordova talk about the discouraging wait for legal retribution for the worst oil spill in U.S. history.

It's been almost 19 years since the tanker Exxon Valdez ran aground at Alaska's Bligh Reef, spurting 11 million gallons of crude into the rich fishing waters of Prince William Sound. In 1994, an Anchorage jury awarded victims $5 billion in punitive damages. That amount has since been cut in half by other courts on appeals by Exxon Mobil Corp.

Now the town of 2,200 looks anxiously to the U.S. Supreme Court, which will hear arguments Wednesday from Exxon on why the company should not have to pay punitive damages at all.

Scores of Cordova residents are among almost 33,000 plaintiffs — including commercial fishermen, Alaska Natives, landowners, businesses and local governments — who could see the $2.5 billion judgment taken away by the high court.

Investors showed immediate enthusiasm for Pittsburgh-based Calgon Carbon Corp., an industry leader in mercury-removal technology. Stocks were up the day of the ruling and continued to rise in the following days.

"We think that long-term it is going to be quite positive for us," said Calgon spokesperson Gail Gerono.

In its Feb. 8 ruling, the U.S. Court of Appeals for the District of Columbia Circuit struck down the Environmental Protection Agency's Clean Air Mercury Rule (CAMR).

The court agreed with opponents that the EPA, in adopting the CAMR for the control of mercury, had violated the Clean Air Act.

Mercury is a neurotoxin, a powerful poison that causes nerve and brain damage. It enters waterways and accumulates in fish and is especially harmful to children.

The 2005 CAMR aimed to cap U.S. power plant mercury emissions, which stand at about 48 tons a year. It would have reduced them by about 20 percent by 2010 and 70 percent by 2018.

Environmental groups and 17 states sued the agency, arguing that the Clean Air Act requires cuts as steep as 90 percent because existing mercury-removal technology can achieve those levels.

Last week's court action leaves the nation with no regulatory control over power plant mercury emissions while the EPA establishes a new rule based on available technology.

"It's sort of ironic," said American Electric Power spokesman Pat D. Hemlepp. "The environmentalists' challenge actually eliminates some of the reductions that would have taken place by 2010."

Some reductions will take place even without regulation.

"The majority of the mercury emissions reductions that we would achieve by 2010 will happen even without that rule (as) a co-benefit of other equipment that we are installing for sulfur dioxide and nitrogen oxides control," Hemlepp explained.

But, he added, "We would have had to also put some activated carbon systems in place on some plants to do some mercury capture--and those are the systems that we will likely end up delaying until we get some clarity on what's going to be required."

Activated carbon, the current industry standard for mercury removal, is injected in powdered form into the flue of a coal-fired plant.

"The activated carbon comes into contact with the mercury and (bonds to it by chemical attraction)," Calgon's Gerono explained. "The activated carbon that holds the mercury is taken to a landfill."

The technology can remove 90 percent of the mercury from the flue stream, she said.