A federal judge on Tuesday paused proceedings in a defamation lawsuit Maine lobstering groups brought against a California aquarium, staying the case until broad questions about how to interpret Maine libel law are answered by an appeals court.

U.S. District Judge John Woodcock had ruled in February that the suit — brought by the Maine Lobstermen’s Association, the Maine Coast Fishermen’s Association and a handful of lobstering businesses — could proceed after nearly two years in legal limbo.

The groups sued the Monterey Bay Aquarium Foundation “for making false and defamatory statements about Maine lobster fishing practices and for misleading consumers and commercial lobster buyers about the integrity of the Maine lobster harvest” after the aquarium’s Seafood Watch program downgraded its rating for Maine lobster. The aquarium claimed that the lobster industry threatens the North Atlantic right whale, and that U.S. and Canadian regulations failed to adequately protect the critically endangered species.

But in a new ruling Tuesday, Woodcock placed a stay on the case while the 1st U.S. Circuit Court of Appeals in Boston takes up questions regarding the proper interpretation of group libel issues and whether the aquarium’s decision to place Maine lobster on a list of foods to avoid constitutes a protected scientific opinion.

Woodcock also granted an interlocutory appeal, a relatively rare legal device used in situations where questions arise that are unrelated to the merits of the case itself, including “a controlling question of law” with substantial grounds for a difference in opinion that could “materially advance the ultimate termination of the litigation,” according to federal law.

The interlocutory appeal is focused on two points the aquarium raised in February.

The first is whether an exception to the group libel law should be granted in this case. The court in February ruled that the case could be exempted from the state’s traditional rules on libel of a broad group, as the plaintiffs were able to demonstrate that they were uniquely impacted by the sweeping declaration on Maine lobster.

Before the proceedings can resume, the appeals court must determine whether that exception “applies to defamation claims brought by a plaintiff group consisting of lobstermen who each suffered similar demonstrable economic harms as a consequence of defamatory statements made against the American lobster as a commercial product,” Woodcock wrote.

Second, the appeals court must determine whether the aquarium’s claims about the lobster industry are protected as a matter of differing scientific opinion.

In their complaint, the plaintiffs allege that the aquarium’s “scientific assertion is factually false and the speaker deliberately ignored and did not disclose the existence of contradictory evidence of which it was aware at the time it made the statements,” Woodcock wrote.

Depending on its findings, the appeals court could send the case back to the lower court for renewed deliberation, move to dismiss the complaint or otherwise terminate the proceedings.

A spokesperson for the aquarium said it “appreciates the District Court’s decision” to grant the appeal and stay proceedings.

“We seek to protect our ability to share critical information with the public and welcome the opportunity the decision presents,” the spokesperson said in a statement emailed Tuesday.

Kevin Lipson, one of the lawyers representing the plaintiffs, said they would brief the issues before the 1st Circuit “as it’s deemed necessary,” but he noted that the court could decline to take up the question of group libel applicability.

“We’re very confident in the trial judge’s determination below, and we are confident that we’ll prevail in the 1st Circuit,” Lispon said on Tuesday. “This is the nature of the judicial process. It is a cumbersome and tiresome thing, but at the end justice will prevail.”

In a brief filed last month, the New England First Amendment Coalition argued that siding with the plaintiffs would be an “unprecedented application of the group libel rule” and threaten news reporting. Doing so could also create a chilling effect related to scientific and public policy debate, the coalition said.