Commercial fishing has been banned for nearly a decade in 490,534 square miles of water around several western Pacific islands and atolls. But that could change based on a recommendation issued Tuesday to President Donald Trump.

U.S. Interior Secretary Ryan Zinke is advising that his boss amend boundaries of the Pacific Remote Islands Marine National Monument — a zone that has been described as one of the largest protected areas on Earth.

As part of his recommendation, Zinke said a regional fishery management council should regulate commercial fishing in the area, which is south and west of Hawaii and surrounds three islands — Howland, Baker and Jarvis — as well as three atolls — Johnston, Wake and Palmyra — plus Kingman Reef.

The Western Pacific Regional Fishery Management Council, which managed commercial fishing in the area before it was protected as a monument by President George W. Bush in 2009 and then expanded by President Barack Obama in 2014, supports Zinke’s recommendation.

But environmental conservation groups, including Earthjustice, oppose any reduction in the monument’s size or easing of restrictions on commercial fishing within.

The U.S. Fish and Wildlife Service describes the monument area as “the last refugia for fish and wildlife species rapidly vanishing from the remainder of the planet,” including sea turtles, dolphins, whales, pearl oysters, giant clams, large groupers and sharks.

“From these protected waters, we can gain knowledge that can be applied elsewhere to improve coral reef management in more populated areas,” the agency states. “They are ideal ‘laboratories’ for assessing the effects of climate change without direct human impacts. And by protecting the Pacific Remote Islands Marine National Monument and the national wildlife refuges within it, future generations of Americans will still have the opportunity to sense the wonder of the world of nature in the midst of the Pacific.”

Zinke made his recommendation in a final report released Tuesday, a day after Trump shrunk the size of two national monuments in Utah via proclamation.

Trump asked in April for a review of several national monuments established by prior presidents under the Antiquities Act. One of those monuments, Papahanau­mokuakea, surrounding the Northwestern Hawaiian Islands, was reviewed by the Interior Department and resulted in no recommended change, according to the report summary.

Papahanaumokuakea was also established by Bush and expanded by Obama.

One other national marine monument, Rose Atoll, established by Bush in 2009 near American Samoa, received the same recommendation as the Pacific Remote Islands monument.

The Interior Department said it received 2.8 million public comments on its monument review, and Zinke said in his report that he met with local government officials and stakeholders as well as conservation advocates and others before making a decision.

Zinke’s memo to the president didn’t suggest specific boundary size changes for the two marine monuments, but recommended that the boundaries be revised. Zinke’s recommendation also said the regional fishery management council should make fishery-management decisions for fishing in the areas.

The Western Pacific council endorsed Zinke’s move, and said through spokeswoman Sylvia Spalding that the council had maintained the areas as pristine with high biodiversity since 1976 when it began managing the region.

“Management of fisheries should be done through the Regional Fishery Management Councils under the Magnuson-Stevens Fishery Conservation and Management Act and not through the Antiquities Act,” the council said in a statement.

The council, which includes fishing industry representatives, said the Pacific Remote Islands monument is mostly deep open ocean with highly migratory fish.

Paul Achitoff, an Earthjustice attorney in Honolulu, scoffed at the Western Pacific council’s claim of maintaining the area as a pristine ecosystem.

“Westpac is probably the single most anti-environmental organization operating in the Pacific,” he said. “Westpac has long been dominated by commercial fishermen. All they care about is maximizing their profits.”

Achitoff, who said Earthjustice attorneys have been engaged in a dozen or so lawsuits over council actions, also believes that the council has an objective to control the turf they were given in 1976.