A federal judge just ruled that, yes, the FDA can regulate a fish as a medicine. His written opinion is kind of a roller coaster for the mind.

Remember the GMO salmon? It was created by a company called AquaBounty back in 1989 and approved by the Food and Drug Administration in November 2015. It’s sold in Canada under the brand name AquAdvantage, and the first batch intended for the U.S. market is quietly growing in an indoor facility in Albany, Indiana. They’re expected to come to market in the U.S. sometime this year.

Or not. The fish, like most other genetically engineered plants and animals, faces adamant opposition in some quarters. Lisa Murkowski, the Republican senator from salmon country–Alaska–has slipped various riders into budget and other bills trying to throw obstacles in AquaBounty’s path. And there’s a longstanding lawsuit brought by a coalition of salmon industry folks and environmentalists that’s trying to completely overturn the approval.

That suit hit an important turning point just before Christmas, when Judge Vince Chhabria of U.S. District Court for the Northern District of California responded to requests for summary judgment in the case, threw out a bunch of claims by the plaintiffs, but let others stand, pending a separate court decision. It’s worth paying attention to, not just for the sake of knowing whether the AquAdvantage is going to find its way into your grocery store, but also because it shows how tricky it can be to get the legal system to do what you want it to.

You can read the opinion for yourself. (Chhabria is the rare judge who produces opinions you can actually read with pleasure.) But to simplify a bit, here’s how the judge responds to the plaintiffs’ main points:  Read the article.

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