President Barack Obama has declared much of U.S. waters in the Arctic Ocean and some areas in the Atlantic Ocean permanently unavailable to oil and gas drilling. The Obama administration announced the action as the government of Canada took similar measures. Canada is placing a temporary ban on new oil and gas leasing in parts of the Arctic Ocean that it controls. Obama is using part of a 1953 law to ban leases for oil and gas drilling. Offshore drilling involves recovering oil or gas below the bottom of the sea. The law the administration is using 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." The Continental Shelf is an area near land where the ocean is not very deep. Environmental groups hope the move will make it difficult for future presidents to change the ban.