Gregory Korte

USA TODAY

WASHINGTON — President Obama declared wide swaths of the Arctic Ocean and 31 Atlantic canyons off limits to oil and gas drilling on Tuesday, part of an 11th-hour conservation action to protect underwater habitats.

Obama's decision comes as Canadian Prime Minister Justin Trudeau announced similar measures Tuesday, as the two leaders called for an Arctic economy "free from the future risks of offshore oil and gas activity."

For Obama, the executive action burnishes an environmental legacy that includes protecting more ocean areas from development than any other president in history. "This withdrawal prevents consideration of this area for any future mineral leasing for purposes of exploration, development, or production," Obama said in a presidential memorandum, a directive similar in effect to an executive order.

But unlike other executive orders, it's unclear whether Obama's action could tie the hands of President-elect Donald Trump. Obama is relying on a provision of the Outer Continental Shelf Lands Act of 1953, which says: "The president of the United States may, from time to time, withdraw from disposition any of the unleased lands of the outer continental shelf."

Obama said the withdrawal was "for a time period without specific expiration." While the White House did not use the word "permanent" to describe the action, many environmental groups did.

But there's precedent for presidents reversing similar actions. In 1998, President Bill Clinton used the same law to renew a moratorium on offshore drilling until 2012. But in 2008, President George W. Bush reversed course, ending the moratorium four years early.

Republicans called the action "an abuse of power," and said it would lead to more reliance on foreign oil.

"The extremes to which this president will go to appease special interests never ceases to amaze," said Rep. Rob Bishop, R-Utah, chairman of the House Committee on Natural Resources. "It is nothing more than ideological chest-thumping from the president for the far left."

But Obama said in a statement that the drilling ban would have little short-term impact. While there are oil and gas reserves in the upper Arctic, most of them are cost prohibitive to extract unless oil prices triple.

Even then, Obama said, "it would take decades to fully develop the production infrastructure necessary for any large-scale oil and gas leasing production in the region — at a time when we need to continue to move decisively away from fossil fuels."

The Atlantic Ocean areas declared off limits to drilling encompass 5,990 square miles, in addition to 4.913 square miles set aside earlier this year as part of the Northeast Canyons and Seamounts Marine National Monument off Cape Cod. The canyons stretch from Heezen Canyon off New England to Norfolk Canyon off the Chesapeake Bay.

The Arctic zone that Obama has withdrawn from oil leasing includes most of the Chukchi Sea and Beaufort Sea, and now totals 125 million acres. But withdrawal would not affect existing leases in a 2.8 million-acre area in the Beaufort Sea.

Also Tuesday, the White House announced a series of Arctic Ocean conservation agreements with Canada that will identify sustainable shipping lanes, phase out the use of heavy fuel oil, ban the opening of unregulated fisheries, and consult with native peoples on future efforts.