After more than 30 years, genetically engineered salmon may be coming to a store near you. Is that good or bad news for the planet?
One day in 1992, a technology entrepreneur sat down for a meeting with a pair of biologists who were studying the genes of fish. The scientists, Choy Hew and Garth Fletcher, were working on a method of purifying “antifreeze proteins” that would help Atlantic salmon (Salmo salar) survive so-called superchill events in the North Atlantic. Normally these salmon migrate out of the subzero ice-laden seawater of the far North Atlantic to overwinter in less frigid waters. Increasingly, though, such fish were being farmed, penned year-round in offshore cages, in near-Arctic waters to which they were not adapted. Fish farmers were looking for a way to keep the fish alive through the winter, and the antifreeze protein seemed like a possible solution.
As the meeting drew to a close, Fletcher and Hew showed Elliot Entis, the entrepreneur, a photo of two fish of equal age. One dwarfed the other. “I sat back down,” Entis recalled recently.
Fletcher and Hew, it turned out, had not just been putting antifreeze proteins into Atlantic salmon. They had also figured out a way to add a growth hormone from Chinook salmon (Oncorhynchus tshawytscha), plus a fragment of DNA from the ocean pout (Zoarces americanus), an eel-like creature that inhabits the chilly depths off the coast of New England and eastern Canada. This genetic code acts like an “on” switch to activate the growth hormone. The result was a genetically engineered superfish that grew nearly twice as fast, on less food, than conventional salmon. Read the article.
This story originally appeared in bioGraphic, an online magazine about nature and sustainability powered by the California Academy of Sciences.