It’s a headline that reads like a punchline, or the setup to one: A synagogue on Manhattan’s Upper West side announced last week that it would no longer serve lox.

“Lox will be eliminated from the menu,” Rabbi Shuli Passow of B’nai Jeshurun wrote in a letter to the congregation, “so we can do our part to reduce the environmental impact of pollution and overfishing. We know that for some this is a heretical move! We are here to support you as you process this change.”

The Great Lox Elimination of 5782 caused an immediate uproar. The Jewish Chronicle posted the story just under news of Queen Elizabeth II’s death.

“PC nonsense!” wrote one Twitter user who identified herself as a former temple member.

Given how many of the old traditions are changing, one person tweeted, “Don’t change this one too.”

Many commenters pointed out that the vast majority of lox, especially in food service, is made from farmed salmon, the use of which does not deplete wild stocks.

Citing “feedback,” just two days after the rabbi’s declaration, the synagogue backpedaled a bit.

“Some felt that we implied that eating lox is immoral or that BJ is boycotting lox or lox providers,” Passow wrote in a follow-up “statement on lox at community Kiddush.” “This could not be farther from the truth.”

But the Upper West Side institution is not really backing down. Rabbi Passow, who acknowledged that most lox is produced from farmed salmon, added that the synagogue will not offer lox both because of increasing costs and “our desire to include more plant-based offerings at community meals.” (It noted, though, that anyone sponsoring a kiddush remains “welcome” to “add it to the menu.”)

I will say this about Rabbi Passow, whom I do not know: She is one brave rabbi for wading into these waters.

In a lot of synagogues, you could switch the Sabbath liturgy itself around, put the amidah where the barchu is and flip aleinu with adon olam and, believe me, you wouldn’t hear a peep.

But leave out the lox? What are you, an antisemite?

Years ago, I was at a Shabbat service in New Hampshire where the Torah reader didn’t know a word of Hebrew, mumbled bit, then rolled up the holy scroll and put it away. No one complained, and I think I know why: Afterwards, there was a really nice spread.

That’s no joke: Food, and its power to bring us together, sustain us and connect us to our traditions is as integral to the Shabbat experience as prayer. In taking on lox, Passow was indeed flipping the liturgy.

And she was entirely right to do so.

If we receive our ethics from Torah and tradition, we live them out at the table. Every meal presents choices on how seriously we take the commandment not to despoil the earth.

And lox, the apex of the appetizing smorgasbord, is an excellent place to start. Much of the farmed salmon production in the world harms the environment and human health: The fish are pumped full of antibiotics; their excrement creates oceanic dead zones; and escaping farmed fish breed with and infect wild stocks, among other problems.

This summer, I saw this impact firsthand on a trip to pristine Vancouver Island, where farmed salmon pens have created what University of British Columbia researchers call a “wicked problem” of sea lice infestation in wild salmon. Sustainably farmed salmon does exist, but it’s no simple task for consumers to suss it out. Take Acme Smoked Fish, the Brooklyn-based company whose silky lox all but blankets Manhattan on any given Sunday.Is Acme lox sustainable?

Answering that simple yes or no questions took me hours — hours — as several different organizations certify sustainability using different standards.

Rob Snyder, Acme’s culture and sustainability officer, acknowledged that it is “a complicated landscape for consumers.”

It doesn’t help that Acme packages don’t carry a sustainability certification label, as they do a kosher label. Snyder said that doing so would be too expensive. It’s about a half-cent a pound, but multiply that times many millions of pounds, and it begins to be real money.

You need a Ph.D. to figure this out, I told Snyder — who, it turns out, has one of those (in cultural anthropology).

Given this confusion, you can’t fault the synagogue for not doing its homework completely — and should credit it for quickly correcting its error.

But where B’nai Jeshurun really deserves praise is putting its ethics on the table. How many Jewish banquets have I been to where the speakers go on about healing the world as the guests dine on feedlot beef or cheaply farmed salmon? How many synagogues have taken steps, as B’nai Jeshurun has, to reduce food waste, introduce more vegan dishes and compost?

“What we eat and how we eat it should intentionally express our values,” wrote Passow.

She’s right — even if sometimes actually doing it requires swimming upstream.