(Bloomberg) -- More than half the registered voters in Republican-controlled South Carolina supported Donald Trump in a poll last month, but there’s at least one area where state leaders are ditching the president to join rival Democrats: a fight against oil exploration off the Atlantic coast.

While no new drilling has been approved in U.S. Atlantic waters, the Interior Department said in 2014 the region may contain 90 billion barrels of oil and 300 trillion cubic feet of gas. The Trump administration, eager to promote new sources of domestic energy, cleared the way in November for an essential first step to future drilling: geologic surveys using sound waves to pinpoint potential oil deposits. Permits could be issued as soon as next month.

That’s sparked a legal challenge by South Carolina and nine other Atlantic states, some coastal cities and environmental groups, to block a survey method companies have used for decades to scout petroleum reserves all over the world. The plaintiffs say the sound waves are unsafe for marine life, but their goal is broader -- to prevent a new energy province off the East Coast that could threaten local tourism and fishing industries.

South Carolina Attorney General Alan Wilson, a Republican, is taking “any and all actions necessary to ensure that we will never see any seismic testing or drilling” in the state’s coastal waters, Henry McMaster, the Republican governor and one of Trump’s early supporters, said in a statement. McMaster took office in 2017 when Nikki Haley was appointed by Trump to be the U.S. ambassador to the United Nations.

Last month, Wilson joined a lawsuit with states run by Democratic governors and attorneys general, including Maine, Virginia, North Carolina, Massachusetts, Delaware, Connecticut, New Jersey and New York. Maryland’s Republican governor also is part of the opposition to seismic surveys. The suit was originally filed in December by several environmental groups, including the Sierra Club and Natural Resources Defense Council, and dozens of coastal cities, such as Beaufort, South Carolina.

‘Nonpartisan’

“I’ve never seen an issue be as bipartisan or nonpartisan as this one,” said Jim Watkins, who lives on a tidal creek on Pawleys Island, South Carolina, and is a chairman of a local group called Stop Offshore Drilling in the Atlantic. “Republican or Democrat, makes no difference.”

On Wednesday, the coalition asked a federal judge in Charleston to block the issuance of any permits by the Interior Department’s Bureau of Ocean Energy Management. On Nov. 30, the National Marine Fisheries Service cleared the way for issuing those permits by granting waivers -- to TGS-NOPEC Geophysical Co. Asa, Schlumberger Ltd., ION Geophysical Corp., CGG Services US Inc. and Spectrum Geo Inc. -- from laws against disturbing marine life. The companies declined to comment.

Seismic surveys involve firing air guns to create acoustic pulses that penetrate the sea floor. Sound waves bounce off geologic formations in different ways, and the data can be used to compile maps that help identify areas likely to have petroleum reserves -- or that may have none at all.

Seismic data makes exploration more efficient and cheaper, and helps governments around the world decide when and where to extract their natural resources, said Gail Adams-Jackson, a spokeswoman with the International Association of Geophysical Contractors, an industry group. Without the data, “countries are making decisions blindly,” she said.

Too Noisy

Spokesmen for the Interior Department and Department of Justice declined to comment on the pending litigation.

Conservationists say the surveys would send acoustic pulses into the sea floor every 10 seconds for months at a time. The blasts are so loud they could damage the hearing of whales, dolphins and other marine species that depend on sound to find mates, avoid predators, navigate and communicate, according to the lawsuit. Of particular concern is the endangered North Atlantic Right Whale, the coalition said.

Government scientists concluded the impact of the sound waves would likely be negligible on animal populations, though some individuals may be affected, Ben Laws, a senior biologist at the National Oceanic and Atmospheric Administration, said during a press call.

Still, then-President Barack Obama denied the seismic-survey applications in January 2017. Two years earlier, more than 70 scientists wrote Obama to say that the impact of the air guns would affect all marine life, and that the Interior Department’s assertion of negligible impacts wasn’t supported by the best-available evidence. By April 2017, Trump had issued an executive order to streamline government permitting, though he’s pledged to ban new offshore drilling in Florida.

“While oil and gas exploration could bring in billions of dollars, doing it without adequate study and precautions could end up costing billions of dollars and cause irreversible damage to our economy and coast,” said Wilson, South Carolina’s attorney general.

Coastal Opposition

“Every East Coast governor and over 90 percent of coastal municipalities in the blast zone are opposed to opening our coast to drilling,” said Diane Hoskins, campaign director at Oceana, one of the environmental groups in the lawsuit. “This is the states versus President Trump.”

Seismic surveys haven’t been used on the Atlantic’s outer continental shelf in about three decades, but the technology is employed in parts of the U.S. already producing oil and gas, such as the offshore waters in the Gulf of Mexico, the inland Permian Basin in Texas, and the Arctic region in northern Alaska.

Opponents say the U.S. doesn’t need to tap into the Atlantic because domestic oil production has surged to a record over the past decade, and renewable sources such as wind and solar power have become a bigger share of the American energy menu. The U.S. produced about 9.4 million barrels of oil a day in 2017 compared to 5.5 million in 2010 and is expected to export more energy than it imports by 2020, according to the U.S. Energy Information Administration.

The Atlantic states, communities and environmental groups said in their lawsuit that the seismic surveys would “irreparably harm marine life” and the communities and businesses that “rely on it for their economic livelihoods.”

As of 2016, South Carolina valued coastal tourism at $8.96 billion a year, with commercial fisheries generating $42.4 million. A report from the American Petroleum Institute says opening the Atlantic to oil and gas exploration could bring more than $1.5 billion in state and local tax revenues over 20 years.

Rick Baumann, who has run a seafood store in Murrells Inlet, South Carolina, for five decades, said he and other business owners who rely on the Atlantic catch are worried about what the seismic tests and, eventually, oil exploration off the coast would mean for their livelihoods. Fisherman already are coping with restrictions on how much they can catch, and when and where they fish, he said.

“Why is it that it’s only on the fishing industry to look after the resources for oil that we don’t even need?” Baumann said. “We have enough to be concerned about with hurricane season, climate change and rising sea levels.”

--With assistance from Jennifer A. Dlouhy.

To contact the reporter on this story: Carlyann Edwards in Washington at cedwards136@bloomberg.net

To contact the editor responsible for this story: Steve Stroth at sstroth@bloomberg.net

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