Interior Secretary Ryan Zinke is recommending that two marine national monuments in the Pacific and four other national monuments be reduced in size, according to a leaked memo.

But the Papahanaumokuakea monument surrounding the Northwestern Hawaiian Islands is not one of them, according to the Washington Post.

The memo from Zinke to President Donald Trump, which included changes to several other monuments, was first reported today by the Wall Street Journal and later obtained by the Associated Press.

The Post said the two Pacific monuments affected are the Pacific Remote Islands and Rose Atoll, both in the Western Pacific.

As provided by the Antiquities Act of 1906, national monument designations give added protections to lands revered for their natural beauty and historical significance with the goal of preserving them for future generations. Restrictions include limits on mining, timber cutting and recreational activities such as riding off-road vehicles.

In April, Trump issued an executive order calling for a review of 27 sites designated by former presidents George H.W. Bush, Bill Clinton, George W. Bush and Barack Obama. The list included all four Pacific monuments.

Conservationists and cultural practitioners have expressed concern that the department could target Papahanaumokuakea for reduction. The monument was established by George W. Bush in 2006 and dramatically expanded to its current 583,000-mile area by Obama in 2016. It is the second largest protected area on the planet.

The other monuments recommended for reduction include Utah’s Bears Ears and Grand Staircase Escalante, Nevada’s Gold Butte, Cascade-Siskiyou in Oregon.

Several are about the size of the state of Delaware, including Mojave Trails in California, Grand-Staircase Escalante in Utah and Bears Ears, which is on sacred tribal land.

No other president has tried to eliminate a monument, but some have trimmed and redrawn boundaries 18 times, according to the National Park Service.

The Associated Press contributed to this report.