It was the early 1980s, and a group of Canadian fish farmers was hoping to find a way for salmon to thrive in the region's frigid waters. So scientists in Newfoundland began experimenting with how to inject them with antifreeze proteins from an eel-like creature known as ocean pout.
Instead, they found a way to make the fish grow more quickly.
That work, more than 30 years ago, led to the controversial breakthroughs that allowed AquaBounty Technologies, a biotechnology company in Maynard, to produce a rapidly growing salmon, which the Food and Drug Administration last week declared the first genetically altered animal fit for consumption.
"We thought if we can enhance the growth rate, that's good for the industry, which can get fish to market faster," said Garth Fletcher, a researcher at Memorial University in Newfoundland, who did the initial experiments that led to the creation of salmon that can grow twice as fast as those in the wild.
Fletcher's technique of inserting growth hormone from Chinook salmon and a "promoter gene" from ocean pout is now considered antiquated technology. But scientists say its commercial application heralds a new era of genetic engineering.
New techniques have allowed scientists to more precisely alter animal genomes by editing DNA to include or exclude beneficial or harmful traits. Researchers are now experimenting with modifying the genes of chickens so they don't transfer avian flu, for example. They also want to develop pigs and cattle that are resistant to foot and mouth disease, and goats that produce a higher level of a microbial protein that may help treat diarrhea in people.
"We're absolutely on the cusp of really making leaps and bounds," said William Muir, a professor of genetics in the department of animal sciences at Purdue University in West Lafayette, Ind. "There's a whole floodgate of things waiting in the wings."
Environmental and consumer advocates have long raised concerns about genetically modified organisms, saying they could cause health and environmental problems.
But the Food and Drug Administration found AquaBounty's salmon to be "safe to eat by humans and animals" on Thursday and said they lack any "biologically relevant differences" with other farm-raised Atlantic salmon.
It was unclear when the company's salmon would be available for supermarkets or restaurants.
"It is too early to discuss commercialization plans, but there are several paths to market that are being considered," said Genevieve Nyren, a spokeswoman for AquaBounty.
The company, through a complex fertilization process, has already produced millions of genetically modified salmon eggs at a hatchery on Prince Edward Island in Canada. The company essentially reverses the sex of the female fish, so that they produce sperm. The so-called neomale fish are then matched with nongenetically engineered females to produce all-female sterile eggs, a safeguard to prevent them from mating with wild salmon.
When the eggs are ready, the company will transfer them to a land-based hatchery in Panama. The hatchery there has a number of safeguards to prevent the modified salmon from somehow entering local waters. But even if they did, the salmon wouldn't be able to survive or find mates in the warm waters of Central America.
Company officials said it takes between 16 and 18 months for their salmon to grow to maturity, half the period it takes conventional fish.
AquaBounty hasn't sought approval to raise its salmon in the United States. The company would need to go through a new, potentially lengthy application process before it could do that.
The company was started in 1991 as A/F Protein, Inc., by a Harvard College graduate, Elliot Entis, who was then working on how to preserve frozen fish. Over time, the company evolved to focus on fish and shrimp farming to address the world's seafood shortages.
After a number of reorganizations, the company took on its current name in 2004 and went public in 2006. Originally based in Waltham, AquaBounty later moved its headquarters to Maynard, but it has only a few employees there. All told, with its operations in Canada, the company has just 21 employees.
One of the company's cofounders, Boris Rubinsky, a professor of mechanical engineering at the University of California in Berkeley, said consumers shouldn't be concerned about the fish.
"I was one of the first people who ate the fish, and I'm alive and doing well," he said.
It may take time for the fish to win widespread public approval.
Legal Sea Foods president Roger Berkowitz, for example, says he is skeptical. "I would not serve it in our restaurants, as I'm personally not convinced of its impact on our bodies, either long- or short-term,'' he wrote in an e-mail last week.
Steve Linder, chief executive of a New York meal service company called Zone Manhattan, said he wouldn't sell the genetically modified salmon, either.
"I don't feel comfortable being a pioneer," he said. "We need to know more before passing it along to our customers."
Jack Bobo, a spokesman for Intrexon Corp., AquaBounty's parent company, said he hoped they would reconsider, especially as companies like Legal Sea Foods have promoted sustainable fisheries.
"We're doing the land-based aquaculture that most environmental groups are actually encouraging," Bobo said. "For the first time, people may be able to locally source salmon, versus flying it in from Chile or Norway."