The Trump administration on Nov. 30 gave five companies permission to conduct seismic airgun blasting off the coast of the Carolinas and other states, a major step toward offshore oil and gas drilling.

Here’s what that would look like, directly off the Carolinas’ coasts and extending over an area twice as large as California:

Ships crisscrossing the ocean dragging dozens of airguns. The guns fire off blasts that can be heard underwater 2,000 miles away up to every 10 seconds, 24 hours a day for months. The five companies would have up to 208 guns in the water at a time and would fire a combined five million blasts over the first year.

A coalition of environmental groups have filed suit in Charleston to prevent the blasts. For the sake of marine life as well as the Carolinas’ coastal beauty and economy, we hope they succeed.

The airguns are used to search for likely oil and gas deposits deep beneath the ocean floor. The deafening noise from the blasts poses a grave threat to dozens of species of marine life, from zooplankton to fish to dolphins and whales. Advocates say the North Atlantic right whale, in particular, is in danger. Only 400 remain, and the sound waves from the airguns would interfere with their mating, feeding and other needs, and possibly cause them to go extinct.

According to the ocean conservation group Oceana, the government has said seismic testing in the Atlantic could injure up to 138,000 marine mammals and disturb “vital activities of millions more.”

The testing would likely lead fairly quickly to offshore oil and gas drilling in the Atlantic, posing the risk of a spill that could damage the Carolinas tourism and fishing industries. The 2010 Deepwater Horizon spill in the Gulf of Mexico showed how bad a spill can be.

All of this risk comes with little upside, except for the oil companies. North Carolina is likely to see little benefit, and environmental groups say exploration would likely yield less than seven months’ worth of oil and six months’ worth of gas.

Legally, the case could boil down to what “negligible” and “small numbers” mean. Under federal law, actions like seismic testing that disturb or kill marine mammals are not allowed unless the National Marine Fisheries Service finds the action will affect “small numbers” of marine mammals and will have a “negligible impact” on any individual species.

“NMFS’s conclusions that the authorized seismic surveys in the Atlantic meet these requirements defy science, law, and common sense,” the suit filed Tuesday argues. Each of the five companies is allowed to harm up to 33 percent of each marine mammal population. That’s hardly a small number. The permission to do the seismic testing violated other laws protecting endangered species as well, the groups argue.

It is telling that most coastal governments and public officials, Republicans and Democrats alike, oppose offshore drilling. We hope the federal judges will take a close look at whether it was proper to issue these seismic testing permits.

— The Charlotte Observer