A study of Peru's anchoveta closure finds the fish feeding the world's fish farms is not the one in your salad dressing, and almost nobody knew.
Peru has closed its anchoveta fishery after a super El Niño, cutting off the fish that feeds the world's fish farms. One scientist's study has found a bigger worry. Nobody at dinner parties knows it is a different anchovy from the one in caesar salad.
On Friday, a man at a dinner party learned that the anchovy in his caesar salad is not the anchovy that feeds the world's fish farms. He put his fork down. He has not picked it back up.
I watched this happen. It was part of my study. We ran it for nine months, across nine dinner parties, with nine bowls of salad.
The implications are, frankly, terrifying.
Some background first. Peru stopped all anchoveta fishing boats from going to sea on 10 June 2026. In mid-August, the pause became a total closure. A super El Niño warmed the sea, and decades of overfishing had already done the groundwork.
Since 1970, the anchoveta has made up about a tenth of the world's commercial fishing catch. That is more than any other fish. More than 90% of it becomes fishmeal and fish oil for fish farms, factory farms and supplement makers. So the food that feeds the food has stopped. That is the boring part. I am moving on.
Here is the real finding. The Peruvian fish is Engraulis ringens. The salty one in your puttanesca is Engraulis encrasicolus. Those are scientific names. They exist so scientists can be correct at dinner parties.
The control group did not help
We told our control group the difference before the starters. That is the group you leave alone, so you can compare. We did not leave them alone, which was a mistake. They still got it wrong.
"We expected some confusion," said my co-author, Dr Owen Marsh. "We did not expect a guest to cry into a breadstick." We are counting that as one data point. Reviewers may disagree.
The result is strong. That means it was unlikely to happen by chance. Chance rarely makes nine people afraid of salad.
Marguerite Vell, chair of the Mediterranean Anchovy Appreciation Society, called the study long overdue. "Our fish is smaller and tastier, and it is fine," she said. "Please stop sending us condolences about the Pacific."
The fishmeal industry declined to comment on the dinner parties. A spokesman said it had a larger problem. We asked if the problem involved croutons. He hung up.
Our next step is clear. We have asked for money to find out whether anyone knows what seaweed farms eat. Early signs are bad. Meanwhile, the boats stay in port and the sea off Peru stays warm. We will look into that if there is funding left over.
