Environmental advocacy groups are cheering what they say is the end of a controversial attempt to market genetically engineered salmon, following a yearslong regulatory and legal battle.

A coalition of environmental, recreation and consumer groups sued the Food and Drug Administration for approving the world’s first genetically engineered food animal nearly a decade ago.

The fish — a salmon designed by AquaBounty Technologies, Inc., to grow quickly — was made with the DNA from several other fish, including the Atlantic salmon.

But advocacy groups argued the new fish could further threaten the endangered Atlantic salmon, especially if they were to escape and mingle with the natural gene pool, and charged that the FDA violated procedural law by failing to consult scientists with relevant expertise, Friends of Merrymeeting Bay said in a written statement Monday. The group was among those that sued, as was Maine and Massachusetts-based Kennebec Reborn.

AquaBounty announced this month that it would be ceasing all fish farming operations, months after the FDA released an updated environmental assessment in response to the coalition’s concerns.

The FDA reaffirmed in September its original finding that the modified fish and production plan “would not individually or cumulatively have a significant effect on the quality of the human environment in the U.S.” and consequently chose not to prepare an environmental impact statement.

Though the company’s statement did not specifically mention the engineered salmon, plaintiffs cited the announcement as a signal that the engineered fish is officially out of production. The company is based in Massachusetts and planned to operate a hatchery in Prince Edward Island, Canada.

“AquaBounty will immediately begin to wind down its Bay Fortune operation, its only remaining operating farm, including the culling of all remaining fish and a reduction of substantially all personnel over the course of the next several weeks,” David Frank, the company’s interim CEO, said in a written statement Dec. 1.

Frank added that the company’s former chief executive, Dave Melbourne, resigned the week prior, and its chief people officer and chief operator officer positions were both eliminated.

John Curtis, a spokesperson for AquaBounty, could not be reached by phone Monday evening and did not immediately return emailed questions about the fate of the genetically engineered salmon.

Still, some opponents of the effort to market genetically modified salmon celebrated the announcement as a victory.

“This is great news!” Ed Friedman, chairman of the Friends of Merrymeeting Bay, said in a written statement Monday. “Atlantic salmon populations including our endangered Gulf of Maine fish are hanging on by a thread — they can’t afford additional threats posed by (genetically engineered) salmon.”

The fate of the company’s research, and genetically engineered fish and food overall, remain uncertain.