A Massachusetts-based company earlier this month cleared the last regulatory hurdle from the Food and Drug Administration to sell genetically engineered salmon in the U.S. Animal genomics expert Alison Van Eenennaam, who served on an advisory committee to the FDA to evaluate the AquAdvantage salmon, explains the significance of the FDA’s move and why some have criticized its decision.

1. How is AquaBounty’s salmon different from a conventional salmon?

The main difference is that AquaBounty’s AquAdvantage salmon grows faster than conventional salmon, and therefore gets to market weight in less time. This is desirable for fish farmers because it means the fish require less feed, which is one of the main costs in aquaculture.

Fast growth is a commonly selected characteristic in food animal breeding programs. The growth rate of chickens, for example, has increased dramatically over the past 50 years thanks to conventional breeding based on the naturally occurring variation in growth rate that exists between individual chickens.

To produce the AquAdvantage salmon, Canadian researchers introduced DNA from the King salmon, Oncorhynchus tshawytscha, a fast-growing Pacific species, into an Atlantic salmon genome 30 years ago. The AquAdvantage salmon are several generations removed from that original fast-growing founder fish. These fish inherited the King salmon fast-growth gene from their parents in the normal way, passed down through sexual reproduction.  Read the article.