President Obama announced that he will designate the world’s largest marine preserve in a large swath of the Pacific Ocean, making the area off-limits to fishing, energy exploration and other activities. The action expands upon and more than quadruples a protective measure that George W. Bush took during his presidency.

Details were still sketchy Wednesday morning about how exactly the rules would be implemented, but the Washington Post reported that the proposal would go into effect later this year after a comment period and would double the area of ocean globally that is fully protected.

The designation is expected to face objections from the U.S. tuna fleet that operates in the region. Fish caught in the area account for as much as 3 percent of the annual U.S. tuna catch in the western and central Pacific, according to the Pew Charitable Trusts.

When Bush created the Pacific Remote Islands Marine National Monument in 2009, he exempted sportfishing to address industry opposition.

Jeff Angers, of the Center for Coastal Conservation, said that although the group was still determining the implications of the measure, it will continue working to exempt sportfishing.

“The environmental footprint of recreational fishing and boating is de minimis,” Angers told Trade Only Today. “We will continue to explain to the administration that recreational fishing is a permissible use, even in the larger area.”

Antonio Fins, of the Guy Harvey Foundation, agreed that it was too early to comment specifically on the proposal, but said the conversation around ocean conservation is positive.

“This proposal sheds attention and light on the challenges facing our marine environments,” Fins told Trade Only. “But we hope the public’s attention isn’t limited to this project. There are a number of very important issues our leaders in Washington are wrestling with in regard to our oceans. One of these is the reauthorization of the critically important Magnuson-Stevens Act, which governs American fisheries.”

The group is also urging that the public give greater attention to the unsustainable rate at which sharks are being killed worldwide, Fins said.

“Our hope going forward is for the president’s proposal to spark broader interest in the many issues facing our seas and that it generates support and funding for organizations carrying out science research to better understand our oceans and bolsters smart regulation and governance of our seas,” Fins said.

A summer public comment period will allow the Commerce and Interior departments to “fully understand the commercial activity out there” and modify the plan, if necessary, White House counselor John Podesta told the Washington Post.

The newspaper said the plan is part of a broader push on maritime issues by an administration that has generally favored other environmental priorities.

The president also will direct federal agencies to develop a comprehensive program aimed at combating seafood fraud and the global black market fish trade. In addition, the administration finalized a rule last week allowing the public to nominate new marine sanctuaries off U.S. coasts and in the Great Lakes.

Under the new proposal, according to two independent analyses, the Pacific Remote Islands monument would be expanded from almost 87,000 square miles to nearly 782,000 — all of it adjacent to seven islands and atolls that the United States controls. The designation would include waters as much as 200 nautical miles offshore from the territories.