This undated 2010 handout photo provided by AquaBounty Technologies shows two same-age salmon, a genetically modified salmon, rear, and a non-genetically modified salmon, foreground. Salmon that's genetically modified to grow twice as fast as normal could soon show up on your dinner plate — if the company that makes the fish can stay afloat. (AquaBounty Technologies /AP)

Salmon that has been genetically engineered to grow twice as fast as its natural counterpart inched a little closer toward the nation’s dinner tables on Friday.

The Food and Drug Administration released its findings that the fish do not pose a threat to the environment and are “as safe as food from conventional Atlantic salmon.”

That removed a key hurdle for a Massachusetts-based company seeking to market the modified salmon, which critics derisively have dubbed “Frankenfish.”

But the move also reignited a long-running debate over whether a nation that already grows and consumes genetically modified plants such as corn and soybeans is prepared to make a similar leap when it comes to animals.

Food-safety activists, environmental groups and traditional salmon fishing industries are staunchly opposed to such a step and are part of a broader global struggle over the use of genetically modified foods.

Countries in the European Union have banned some genetically modified foods outright and instituted tight labeling requirements on foods that contain modified ingredients. Countries such as Russia, Japan and Peru also have instituted restrictions on genetically altered foods.

AquAdvantage, the fast-growing fish at the center of the controversy in the United States, is an Atlantic salmon that contains a growth hormone from a Chinook salmon and has been given a gene from the ocean pout, an eel-like fish. The result is a fish that grows larger and faster than traditional salmon.

Under the company’s proposal, no modified salmon would actually be produced in America. The eggs would be produced at a facility on Prince Edward Island in Canada and shipped to another facility in Panama, where they would be harvested and processed. In its assessment, the FDA said the likelihood that the altered fish could escape containment and reproduce in the wild is “extremely remote.”

Friday’s assessment could pave the way for ultimate approval of the engineered fish. The FDA must first take comments from the public on its report for 60 days before finalizing it. After that, the agency will decide whether to give AquaBounty the green light to begin marketing its fish to Americans.

“We’re encouraged by this milestone, and we’re grateful that they’ve elected to continue a ­science-based process,” Ronald Stotish, president of AquaBounty Technologies, said in an interview. “We think this is progress.”

Friday’s determination echoes findings from two years ago, when the FDA held days of public hearings and convened panels of scientists, staff members and industry officials to consider potential impacts of the altered salmon.

Since then, the approval process for the fish has remained at a virtual standstill. But the public fight over it has churned on.

Some consumer and environmental conservation groups have claimed that the FDA has failed to fully scrutinize the product and its potential effects. Lawmakers on Capitol Hill, particularly those from the Northwest, have backed legislation that would ban the fish outright or require specific labeling about its origins.

“The notion that consuming Frankenfish is safe for the public and our oceans is a joke,” Sen. Mark Begich (D-Alaska) said in a statement Friday. “I will fight tooth and nail with my Alaska colleagues to make sure consumers have a clear choice when it comes to wild and sustainable versus lab-grown science projects. . . . Today’s report is by no means the final say on this issue.”

Rep. Don Young (R-Alaska) was more blunt.

“You keep those damn fish out of my waters. It will ruin what I think is one of the finest products in the world,” Young said in an interview, saying he fears that the spread of fish farms could eventually contaminate the wild salmon industry in Alaska. He wants to force delays in any FDA approval.

“If I can keep this up long enough, I can break that company,” he said, referring to AquaBounty, “and I admit that’s what I’m trying to do.”

So far, he appears to have had some success. Stotish said his company has cut back to about a dozen employees, down from more than 30, while awaiting the government’s approval.

The nonprofit Center for Food Safety also sharply criticized the FDA’s assessment, calling the decision “premature and misguided.”

“It is extremely disappointing that the Obama Administration continues to push approval of this dangerous and unnecessary product,” executive director Andrew Kimbrell said in a statement.

Meanwhile, industry executives and some agency scientists insist that there is no discernible difference between the altered salmon and wild salmon. Stotish has argued that his salmon would help bolster the world’s food supply, lower prices and require fewer resources — all in a safe and sustainable way.

Scientists at the FDA have generally seemed to agree, at least thus far. In a briefing document ahead of the public hearings in 2010, FDA staffers wrote, “We have found no biologically relevant difference between food from [AquaBounty salmon] and conventional Atlantic salmon.”

How long a final approval might take is anyone’s guess.

AquaBounty first applied for permission to sell its genetically altered fish in 1995, and even by FDA standards, its application has moved at a glacial pace in recent years.

“Because this is a first-of-kind application, FDA’s goal is to be as comprehensive as possible in its evaluation and anticipate all outcomes,” FDA spokeswoman Morgan Liscinsky said Friday.

Gregory Jaffe, director of biotechnology at the Center for Science in the Public Interest, said he understands the agency’s caution but believes the approval process has been excessively long.

“Applicants have a right to a timely, scientifically justified decision,” said Jaffe, who participated in the 2010 hearings about AquAdvantage and said he had no real safety concerns with the product.

He said the current fight is less about a relatively small company than about a critical concept — whether the United States should embrace genetically engineered animals for consumption and what the implications of that might be on a large scale.

For now, those answers will have to wait. Jaffe said that even if AquaBounty wins approval for its genetically modified fish, its limited production capacity means that it would make up only a tiny fraction of the U.S. market.

At least for now.

“This is not going to become the majority of our salmon overnight,” Jaffe said. “It won’t be as hard as winning the lottery, but it will be hard to find a modified salmon steak.”