JUNEAU, Alaska — One researcher has withdrawn and another has been excused from participation in the upcoming review of studies released by the group behind a massive mine project in southwest Alaska.

Both David Montgomery’s withdrawal and Daniel Schindler’s dismissal came last month, just weeks before the start of what has been touted as an independent, objective look at the science put forth by the Pebble Limited Partnership.

The Keystone Center assembled the panels on behalf of the Pebble, which is looking to develop a huge gold-and-copper prospect near the headwaters of a world premier salmon fishery. Pebble earlier this year released tens of thousands of pages of data, meant to provide an in-depth look at the environmental and social conditions in southwest Alaska’s Bristol Bay region. Critics consider the data incomplete and the review process more about scoring points in the court of public opinion than accomplishing anything substantive.

“My concern is, they’re checking off a box,” to show decision-makers that they consulted with researchers and scientists, said Lindsey Bloom, a critic of the proposed Pebble Mine who is with Trout Unlimited.

Pebble is funding Keystone’s work, but the panel members are not being compensated, said Todd Bryan, a senior associate at the center. The panel discussions begin Tuesday in Anchorage.

Montgomery, a professor of earth and space sciences at the University of Washington and a MacArthur Fellow who’s written about salmon runs, said he initially agreed to participate partly because he felt it important that a project like the proposed mine undergo scientific review and scrutiny.

He said he considered this an important process but eventually came to believe it was flawed and that he couldn’t evaluate the adequacy of the Pebble studies without a mine plan scenario — “without knowing what the impact or risk would be,” he said.

In his resignation letter, dated Sept. 15, he said he “cannot in good faith participate in the process.”

Bryan said in an interview that he didn’t understand where Montgomery was coming from. He said the studies looked at baseline conditions in the region and that one doesn’t need a mine plan for that. He said the baseline studies inform the decisions around mine planning, and the panels are to look at how well those studies were done.

He said Keystone envisions a future review of any mine plan Pebble puts forth.

Schindler, a professor of aquatic and fishery sciences at the University of Washington who’s known for his expertise on Bristol Bay salmon, was dismissed for alleged bias.

That action apparently centered around a piece he co-wrote, which was published in June on a Seattle news website, crosscut.com. It said there was “clear evidence” that mining activities and related infrastructure would pose “significant long-term risks to productive salmon ecosystems.” It also urged the U.S. Environmental Protection Agency to move forward to protect the region.

EPA has drafted its own assessment of the region, looking at the impacts of large-scale mining. Critics of the agency’s work, including Pebble, have derided it as premature and an overreach. A peer-reviewed analysis is expected soon.

Bryan called Schindler’s dismissal “extremely traumatic,” because he said Schindler has done a lot of sound research in the region. Bryan said he thinks Schindler could be an objective reviewer. However, Bryan said there’s a lot of scrutiny — by people on both sides of the debate — on who serves on the panels. With that article, he “kind of became an activist,” and it was thought that Schindler would automatically lose half his audience for perceived bias, he said.

Schindler said he would have provided an objective review, “absolutely.” He said he felt he had the expertise and experience to contribute substantially. His past commentaries “were motivated by what I saw as scientifically false assertions by proponents of the mine,” he said in an email. The piece on the EPA review was motivated, he said, by efforts to discredit EPA’s science.

“If scientists don’t step up to challenge scientifically incorrect statements (by either side of the debate), then who will?” he said. “Keystone incorrectly and unjustifiably defined my previous contributions as acts of advocacy. This is a convenient ploy when science fails to support your political position: write off the scientists as advocates.”

Bryan defended the integrity of Keystone’s review process. He said about 20 panelists are participating.