But Max Fish is not more of the same; it comes with a respected downtown pedigree, not least because of Ms. Rimkus’s founding determination to make the bar a haven for artists, whose work lines the walls. It also drew celebrities when the neighborhood reached its last bohemian heyday of sorts, in the ’90s and early aughts, bringing in the likes of Jim Jarmusch, Chan Marshall, Nick Cave and Johnny Depp.

It remains to be seen whether the bar’s success can be replicated in Williamsburg, a neighborhood in the grips of the same rampant development that is chasing Ms. Rimkus now. The new site’s listing price earlier this year was $14,000 a month. A representative for the property manager said the place had been leased to Max Fish, but would not say at what price. Ms. Rimkus seems intent on moving much of the bar’s colorful contents, too. “We’ll take the spirit and everything with us,” she is quoted in an online petition to drum up support for the move.

Other downtown haunts have made the eastward leap. The Knitting Factory relocated to Williamsburg in 2009, and the little East Village taco joint, Snack Dragon, recently opened an outpost there, too. Mama’s, the comfort food restaurant formerly of the East Village, briefly opened in Williamsburg and did well until a crucial investor pulled out, said its owner, Jeremiah Clancy.

“There’s a lot of jumping over the river, which I think there should be because there’s tons of kids,” Mr. Clancy said. “And unlike when I was growing up in New York City, they have so much money. They have so much money to spend, it’s ridiculous.”

While Max Fish’s shuttering on Ludlow Street may have long been in the cards, the news was met grimly by proprietors of other Lower East Side stalwarts, who have bidden goodbye to a steady stream of local hangouts — among them Mars Bar, the Life Café, the Lakeside Lounge and the Pink Pony, which adjoined Max Fish. Also soon to go will be Motor City.

“I’m sad to see the whole neighborhood disintegrate,” said Jennifer Gilson, owner of the Living Room, also on Ludlow Street. Its lease is up in August, and Ms. Gilson is hoping to reopen a few blocks north. “I don’t want to be pushed out to Brooklyn.”

But workers and owners at even more whiskered Lower East Side landmarks — Katz’s Delicatessen, which has passed the century mark, and Russ & Daughters, which is nearing it — met the news with resignation bordering on nonchalance. The rapid gentrification of the neighborhood made the bar’s departure feel inevitable, they said.

“Everything else is gone,” said David Manheim, 38, a waiter at Katz’s. “Why shouldn’t Max Fish be gone too?”