Interior Department land managers have been ordered to review hunting and fishing regulations on department lands to determine how they conflict with state regulations.

In a memo Monday, Interior Secretary Ryan Zinke ordered the review with an eye toward deferring to state management unless it conflicts with federal law.

"The Department recognizes States as the first-line authorities for fish and wildlife management and hereby expresses its commitment to defer to the States in this regard except as otherwise required by Federal law," Zinke wrote in the memo to heads of bureaus and offices.

The memo was condemned by Public Employees for Environmental Responsibility, a nonprofit group that advocates for the environment and protects federal whistleblowers.

The group distributed Zinke's memo Tuesday in a news release and called it a stunning abdication of federal primacy for wildlife management on federal lands. Many state wildlife agencies are funded by hunting and fishing license fees and pursue practices, such as predator control, that maximize that revenue, executive director Jeff Ruch said.

"Federal parks, preserves, and refuges have a mission to protect biodiversity and should not be reduced to game farms," Ruch said.

Interior Department spokeswoman Heather Swift did not respond Tuesday to an email seeking comment on the memo.

In Alaska, state and federal wildlife authorities have clashed over whether state "intensive management" would be extended to federal lands. State officials have conducted extensive predator control, exterminating wolves, black bears and grizzly bears, to increase populations of moose, caribou and deer.

Managers of federal refuges in Alaska have rejected state attempts to extend predator control measures as well as liberalized state hunting regulations that would have allowed what they consider an over-harvest of grizzly bears.

Federal law that created wildlife refuges say they are to be managed for biodiversity, according to federal managers.

The U.S. Fish and Wildlife Service under the Obama administration in 2016 adopted a blanket policy to ban predator control on federal wildlife reserves in Alaska. That blanket rule was overturned in the early months of the Trump administration, meaning state proposals for predator control returned to a case-by-case review.

Zinke in his memo cited a 1983 codified policy stating that state authority for fish and game management remains the "comprehensive backdrop" applicable in the absence of overriding federal law.

State wildlife and fishery agencies, he said, practice sound conservation and management based on sustainable practices.

With that in mind, Zinke called for Interior Department offices within 45 days to prepare a review of federal regulations that are more restrictive than state policies.

Within 90 days, each office was ordered to provide Zinke's deputy secretary with detailed recommendations for better aligning federal rules with state rules.

After receiving the recommendations, the deputy secretary will have 120 days to deliver an implementation plan to Zinke.

Geoff Haskett, director of the National Wildlife Refuge Association, and former Alaska regional director for the U.S. Fish and Wildlife Service, said he was glad Zinke noted that federal law can override state authority.