I was in Miami Beach recently, eating a salad at an outdoor cafe on bustling Lincoln Road and half expecting Isaac Bashevis Singer to come strolling by on his way to Wolfie's. Of course, Singer died in 1991, and Wolfie's made way for condos 10 years ago, but we all have our ghosts. Mine happen to be pale Jewish men in cocoa-colored straw hats, and delis with heaping bowls of pickles on each table.

I'm not the only one who still finds it surprising that the once-vibrant Jewish culture of Miami Beach is as faded as a canvas beach umbrella. Marcia Zerivitz, founding executive director of the Jewish Museum of Florida, tells The New York Times that she still hears from filmmakers and writers who want to capture the Miami Beach of kosher hotels and Yiddish theaters and seaside kuchalayns.

"I get calls like that all the time, especially from California and up East," she says. "I say: 'Sorry, you're many, many years too late. There's nothing left.'"

Abby Goodnough's April 3 Times article doesn't so much report as remind the reader that the Orthodox synagogue Kneseth Israel is now a glitzy special-events space, that the beach's last kosher resort hotel (the Saxony) and oldest synagogue (Beth Jacob) both closed in 2005. Demographer Ira Sheskin tells her that the Jewish population is down to 16,500 from 60,000 in 1982. (The Fontainebleau and the Eden Roc still fill up at Passover, Goodnough writes, but both hotels are a few miles from what was the historic heart of Little Jerusalem.)

Jewish Miami Beach barely exists even in the city's archives, to the dismay of historians. Nor do I find a trace of it in A Living Lens, a new collection of photographs from the archives of the Forward. While the marvelous book portrays 20th-century American Jews in all their painful, celebratory, political, messy, engaged, oblivious, and contradictory glory, there's little sign of the Art Deco paradise that drew waves of Jews to the white sands and pink skies.

What's left of Jewish Miami Beach can be found in books and memoirs – in Singer's stories, of course, and in books by writers, now my age, who remember visits with elderly relatives in the 1960s and '70s. Daniel Mendelsohn's book The Lost opens with a funny and heartbreaking vignette about his visits to his Miami Beach relatives. Old Jews yell above the blare of black-and-white television sets, telling jokes that climax with incomprehensible Yiddish punch lines. The heartbreak comes from knowing what these Yiddish-speaking Jews survived, and remembering those who didn't make it out of the cellars and camps and haylofts to spend their final days in shuffling distance from Collins Avenue.

That's Mendelsohn's childhood, not mine. When my relatives moved to Florida they ended up many miles north, in Hollywood and Delray Beach and even Jacksonville. And yet I know why I'm drawn to the legend of Miami Beach: For most of my now 46 years it represented the way Jewish was done in America, a sort of platonic ideal whether you lived in an inner-city Jewish ghetto or out in the burgeoning suburbs. The whole vocabulary of secular Jewish culture – the delis, the Yiddishisms, the entertainers, the smells, the arguments – that's gone. It was already fading when I was a kid, when the baton was passed from Old World Jews to their leisure suit-wearing offspring to their bell-bottomed teenagers.

It wasn't just a shift in fashion but worldview – from a time when Jewish culture was inescapable – for good and bad – and when a combination of anti-Semitism from the outside and ethnic magnetism from the inside sustained a Jewish identity in the face of assimilation. Usually you didn't have to choose to be Jewish – that was chosen for you the day your parents brought you home to your Jewish neighborhood, took you on vacation where other Jews gathered, and stood you on line on Election Day and showed you how Jews voted. Jewish was the default. The option, difficult at first but easier as the decades rolled on, was to leave Judaism or assign it a cameo role in the drama that was your life.

Today Jewish survival favors those who choose Jewish. The future, demographically speaking anyway, belongs to those making proactive Jewish choices, from belonging to a synagogue to sending children to day school to attending a college with a sizable Jewish population. It's a wonderful thing, the growth of Jewish day schools, the thickly Jewish activism of the Ramah and Hillel kids, and the renaissance now under way within the Orthodox world. (The Times article on Miami Beach reports that "an Orthodox Jewish community is flourishing around 41st Street.")

But there is a bittersweet aspect to the decline of ethnic Judaism. A sense of what was lost is on display at the Museum of the City of New York, where an exhibit based on the Forward book and celebrating the newspaper's 110th anniversary went on display on Sunday. If nothing else, the exhibit and book, like the Yiddish Forverts and its English-language offspring, represent choices. The secular and the religious, socialists and Zionists, rabbis and union organizers, actresses and settlement house workers: The photographs depict diversity, and yet the certainty that no matter what the individuals were engaged in, they were "doing Jewish."

So let's celebrate the culture of Jewish learning and observance we are creating in our synagogues, day schools, and Jewish studies departments. But let's also remember the things we left behind, when the smell of the sea breeze could remind us of the diversity of American Judaism.