Just how friendly to the oil and gas industry will a Trump administration be? Consider the president-elect's key nominations so far.

His choice for secretary of state is Rex Tillerson, the chairman and CEO of Texas-based oil giant Exxon Mobil. His pick for energy secretary is former Texas Gov. Rick Perry, whose aborted 2016 presidential run's top contributor was the oil and gas industry and who sits on the board of Energy Transfer Partners, the Dallas-based company behind controversial oil pipeline projects in Louisiana, Texas and North Dakota. To run the Environmental Protection Agency, Trump has tapped Oklahoma Attorney General Scott Pruitt, a climate change skeptic who helped form what a New York Times investigation called an "unprecedented, secretive alliance" with the oil and gas industry.

Given those selections, it's no surprise that opponents of opening the Atlantic Ocean to oil and gas drilling are worried about the durability of President Obama's decision against doing so.

Back in March, the Obama administration dropped the Atlantic from its five-year offshore leasing plan covering the time period from 2017 to 2022. It had been considering offering drilling leases in the area that extends from Virginia to Georgia, but the proposal met with massive local opposition from environmental advocates, the fishing industry and coastal businesses dependent on tourism.

With Trump's inauguration looming, Atlantic drilling opponents are now pressing President Obama to use executive powers outside the normal rule-making process to permanently protect the region from oil and gas development.

Last month, the climate advocacy group NextGen launched a petition calling for a permanent ban on drilling in both the Atlantic and Arctic, while New Jersey's two U.S. senators joined with environmental advocates to ask for a permanent ban in the Atlantic. This week, more than five dozen businesses along the Atlantic Coast from South Carolina to Connecticut wrote a letter to the president urging prompt action:

For the sake of our beaches, coastal communities and the significant boon coastal tourism provides to our economy, we the undersigned local business leaders strongly urge you to ensure permanent protection of the Atlantic Ocean by withdrawing it from all future oil and gas development. The potential economic losses that offshore drilling would bring to our existing coastal economies and the potential for damage to treasured coasts and marine resources would be devastating. Nearly 1.4 million jobs and $95 billion in gross domestic product rely along the Atlantic coast rely on clean beaches and a healthy ocean environment. Our clean beaches, coasts and oceans are worth too much to risk to the dangers of offshore drilling.

He'd take such an action under Section 12(a) of the Outer Continental Shelf Lands Act (OCSLA), the federal law governing offshore drilling. The provision allows the president to "withdraw from disposition" any area of the Outer Continental Shelf that hasn't already been leased for oil or gas drilling. The law does not limit the size of the area that can be withdrawn, and allows it be withdrawn for any public purpose.

The provision has been used by six presidents over the past 65 years, with some of the withdrawals constituting several hundred million acres. The first withdrawal came in 1960, when President Eisenhower removed from play parts of Florida's Key Largo Coral Reef Reserve. In 1990, President George H.W. Bush withdrew another area off the Florida coast. There have also been withdrawals of areas off the coasts of Alaska, California, Massachusetts, Oregon and Washington. Some of the withdrawals have been time-limited, while others have been permanent.

The catch is that the law allows presidents to create protected areas but does not authorize them to reverse such protections, according to a briefing paper from the Natural Resources Defense Council and Earthjustice. The groups' analysis looks at the OCSLA alongside the federal Antiquities Act, which authorizes presidents to reserve parcels of land as part of national monuments:

While the text of Section 12(a) delegates to Presidents the power to create protected areas, like the Antiquities Act it does not authorize them to undo those designations. A legal opinion from the U.S. Attorney General found that such congressional delegations operate in one direction only: they do not imply a power to undo. "[I]f public lands are reserved by the President for a particular purpose under express authority of an act of Congress, the President is thereafter without authority to abolish such reservation." The opinion explained that "the reservation made by the President under the discretion vested in him by the statute was in effect a reservation by the Congress itself," and that, except where Congress expressly provided, "the President thereafter was without power to revoke or rescind the reservation." While the opinion referred to the Antiquities Act, the legal rationale applies equally to Section 12(a)'s withdrawal authority. As explained by a previous Attorney General's opinion it quoted, "unless it be within the terms of the power conferred by that statute, the Executive can no more destroy his own authorized work, without some other legislative sanction, than any other person can.

To reverse a permanent protection established by the president, Congress would either have to change the OCSLA or pass stand-alone legislation.

In a Republican-controlled Congress friendly to the oil and gas industry, there would undoubtedly be support for taking such drastic steps to undo protections imposed by President Obama. But there would also be opposition — even among other Republicans. GOP members of Congress who've come out against Atlantic drilling and/or seismic testing, the precursor to drilling, include Reps. Walter Jones of North Carolina, Mark Sanford of South Carolina, and Curt Clawson, Ron DeSantis and Ileana Ros-Lehtinen of Florida.

Earlier this month, Franz Matzner, director of NRDC's Beyond Oil program, told reporters that he's optimistic about the prospects for a permanent ban, saying his group has "pretty good indications" President Obama will take action. Such a move would be popular with the public, as a recent poll commissioned by the NRDC and League of Conservation Voters found that 59 percent of Americans support permanent protections for both the Atlantic and the Arctic.