Seismic blasts could echo under water and core samples could be drilled offshore as companies search for oil and natural gas, under permits the federal government is considering granting to nine companies.

But exploration isn’t likely to happen any time soon.

Federal public input meetings on the environmental impact of granting the permits takes place today in North Charleston, a preliminary part of the permitting process.

The issue has been a volatile low burner for years, with the off-and-on progress of exploration plans and back-and-forth federal policy.

Conservationists say the potential harm oil and natural gas drilling could do to wildlife, an $18 billion tourism industry, fishing and other interests outweighs any economic or energy benefits.

Experts generally agree that not a whole lot of oil lies off South Carolina. They disagree over how much natural gas might be out there, and whether it can be found in the type of field that can be commercially drilled.

But industry representatives say the bottom line is, nobody knows.

“No one has looked in probably 20, 25 years,” said Randall Luthi, president of the National Ocean Industries Association trade group. In that time the testing has become much more sophisticated. Four or five times more oil and natural gas have been found in the Gulf of Mexico than were thought to exist in the 1980s, he said.

Meanwhile, for the moment, the whole permitting procedure might be moot.

The nine companies applied for the permits before the Atlantic waters were temporarily closed to exploration after the Gulf oil well leak disaster in 2010.

Leases are granted for five-year periods. None have been granted in the Atlantic for the next five years.

The exploration companies are paid by oil company clients with immediate interest in the data they collect, Luthi said.

“There’s no client who’s going to buy data that’s of no use to them,” Luthi said. “It’s not even putting the cart before the horse. It’s putting the cart out without the horse.”

Seismic exploration involves firing off air guns dragged by ships to create a series of blasts to read the “echo” beneath the sea floor.

Exploration companies plan to focus on the Continental Shelf some 50 to 60 miles out, but leases could allow them closer in. Conservationists worry for the threat to wildlife such as the critically endangered right whale, which is sensitive to noise.

The Coastal Conservation League is formally opposing the permits for two reasons:

The permitting decisions are being made before an overall analysis whether oil and gas development is ever going to be appropriate off the Southeast coast in light of potential damage to the environment, coastal tourism and other industry.

The exploration data collected will not be made public, so there’s no way for the public to weigh in on whether oil and natural gas drilling is justified.

“It’s the government working behind the scenes” with the oil and gas industry, said Hamilton Davis of the conservation league.

The public input meeting “is standard operating procedure for them, to answer a few questions, make a few comments, then go ahead with what they were planning to do anyway,” he said.

Reach Bo Petersen at 937-5744, @bopete on Twitter or Bo Petersen Reporting on Facebook.

Science and environment reporter. Author of Washing Our Hands in the Clouds.