The future of large sections of the Pacific Ocean protected from commercial exploitation — areas designated as marine national monuments — has become more uncertain in recent days.

A draft memorandum from U.S. Interior Secretary Ryan Zinke, leaked to news media outlets, re- commends modifying or shrinking the boundaries of 10 national monuments, including the Rose Atoll and the Pacific Remote Islands marine monuments.

Zinke recommended that these marine monuments be opened to commercial fishing.

The memo is a preliminary one, lacking specifics. How it will be received by the White House is unknown.

Notably, it does not recommend any changes to one of the biggest marine sanctuaries of all — the Papahanaumokuakea Marine National Monument, created by President George W. Bush and vastly expanded by President Barack Obama in 2016 over the protests of Hawaii’s commercial fishing interests and the Western Pacific Regional Fishery Management Council.

But conservationists are worried, and rightly so. Zinke’s recommendations appears consistent with the Trump administration’s enthusiasm for opening up federal holdings to resource exploitation. The memo includes recommendations that would allow “traditional uses” now restricted, including grazing, logging and commercial fishing.

Fishing industry representatives have lobbied President Donald Trump to reopen the marine monuments to fishing, including the hundreds of square miles encompassed by the Pacific Remote Islands. It would be an unnecessary mistake.

Opening up vast expanses of relatively undisturbed ocean to commercial fishing vessels could cause significant long-term changes to ecosystems already under stress from other factors, including global warming and coral bleaching.

There is no compelling reason to choose short-term commercial gain over safeguarding the long-term health of the world’s oceans. At the very least, a careful balance should be maintained between the competing interests.

Conservationists and marine biologists argue that the life in the world’s vast oceans are inextricably connected and interdependent. The best and only way to ensure the long-term viability of the world’s oceans, including the future availability of seafood, is to protect as much as 10 and 30 percent from commercial exploitation, allowing marine life to replenish itself. At present, about 5 percent comes under some form of protection.

The fishing industry argues that those restrictions do more harm than good. A responsibly managed fishery like Hawaii’s longliners can sustain fish species while meeting the market demand for reasonably priced seafood, including the popular ahi. It’s a strong argument, but with the world’s insatiable appetite for seafood, it’s not a given.

The Rose Atoll monument, 13,451 square miles in or near American Samoa, was declared a monument by Bush in the waning days of his administration. It consists of a speck of land and miles of ocean, including reefs that support a diverse collection of terrestrial and marine species the monument status was intended to protect.

The Pacific Remote Islands monument was created by Bush in January 2009 and expanded by Obama in September 2014. It covers roughly 500,000 square miles around seven islands and atolls south and west of Hawaii, including Howland, Baker and Jarvis islands; Johnston, Wake and Palmyra atolls; and Kingman Reef.

The monument contains what the U.S. Fish and Wildlife Service describes as “the last refugia for fish and wildlife species rapidly vanishing from the remainder of the planet,” and noted that the largely pristine waters serve as “key stepping stones for the colonization and dispersal of species between the eastern and western, and the northern and southern Pacific Ocean.”

Both monuments, along with Papahanaumokuakea and other protected marine areas, demonstrate a commitment to careful and responsible stewardship. Maintaining healthy oceans will ensure that future generations inherit what we now enjoy.