President Barack Obama announced Tuesday that he has removed hundreds of millions of acres of federal land in the Atlantic and Arctic from potential offshore oil and gas drilling — a move that could further complicate pledges made by President-elect Donald Trump to increase domestic oil production. Obama used the Outer Continental Shelf Lands Act to protect 115 million acres of land in the Chukchi and Beaufort seas in the Arctic, and offshore acreage from Massachusetts to Virginia in the Atlantic.