Maryland's crab capital is built on oysters—literally.

Crisfield, now a crabbing town of 2,700 on the Chesapeake Bay in eastern Maryland, once caught and processed so many oysters that the sheer number of leftover shells thrown into the ocean created a ten-foot-thick layer of new land on which part of the town's center still sits.

It didn't take long for the fishery to inch to the brink of disappearing due to overfishing, and a disease that swept the bay in the 1970s put the nail in the coffin of Maryland's iconic oyster haul. The economy transformed. In Crisfield and other towns along Maryland's soggy Chesapeake shores, blue crab became king.

But these days, things are changing—again. Even as young people leave seeking new opportunities, and as the shoreline itself is claimed by erosion and rising sea levels, there are signs that the Chesapeake's native eastern oysters are coming back. Slowly, yes, but enough to spark a glimmer of hope in the traditional fishing communities trying to find a place in the modern, global seafood industry and, in some cases, still reeling from Hurricane Sandy.

"Oysters were important for these little small towns on the bay," said Casey Todd, who, with his brother, runs MeTompkin Seafood, the only seafood operation left in Crisfield that processes oysters. "And it's been missing."

But that changed in 2012 when the native eastern oyster staged a surprise comeback. Fishermen—locally called "watermen"—saw their oyster hauls triple, even quadruple. Watermen in Maryland brought in 345,621 bushels of oysters in the 2012-2013 season, up from 116,859 bushels the year before.

It was a welcome change after the dismal early 2000's, when hauls barely reached 20,000 bushels statewide.

And the haul grew even more, to more than 430,000 bushels in 2013-2014 season, and settled just shy of 400,000 last year. The 2013-2014 haul was the largest in Maryland since 1986—valued at around $14 million—and watermen are hoping the bay can keep up that momentum.

"With the comeback of oysters you've got income in the winter and income in the summer," Todd said, referencing that the oyster fishery is only open in the winter, when the blue crab fishery is closed. "Watermen have had income the past three years."

He added: "Every small town on the bay has been impacted by oysters, no question."

Virginia's Chesapeake Bay watermen saw the surge, too.

"Oysterin' has been outstanding, and super prices," said James "Ooker" Eskridge, a waterman and mayor of Tangier Island, Virginia. "It is the economy. When the watermen are doing good, everybody is doing good on the island."

Tangier's longtime watermen welcome the native oyster's comeback. Strickland Crockett, 87, remembers his early days as a waterman in the 1930s, when there were so many oysters that it was hard to turn a profit because the price was so low.

"Last three or four years I've noticed a lot of oysters is striking on these pots," Crockett said. "They were real plentiful last winter here."

Even though the numbers look good in the context of the last few years, the fishery will likely never be the same, researchers say. It's estimated that the eastern oyster fishery in the Chesapeake Bay is less than one-percent of what it was when European settlers first arrived. In the late 1800s, Maryland's watermen were bringing in more than a million bushels a year.

State agencies and universities have long lead the effort to rebuild—or at least stabilize—the Chesapeake's eastern oyster fishery. However, in recent years, the seafood industry and private landowners are stepping up as well. To date, around 1,500 waterfront property owners in Maryland have partnered with the state's Department of Natural Resources to grow millions of oysters off private piers.

The oyster fishery's growth can at least be partly attributed to that program, Stephan Abel of Maryland's Oyster Recovery Project wrote in an emailed statement.

"Because oysters are filter feeders, farm-raised oysters help clean the Bay's waters without adding harvest pressure on the wild population," he wrote.

Back in Crisfield, Casey Todd of MeTompkin Seafood is trying to raise his own oysters to help stabilize his operation's oyster haul.

Todd's operation has grown to six tanks. Oyster larvae are set on shells in the tanks for about a week, are dumped into the bay, and then Todd waits for them to grow and hopes they don't get stolen.

"We're just getting started," Todd said. "We're trying to get our beds up and running."

Virginia oyster growers have been picking up the pace, too. In 2013, growers sold around 31 million single oysters—around 200,000 bushels—up about 10 percent from the year before, according to The College of William & Mary.

The goal is for MeTompkin to have around 10,000 bushels come from tank-raised oysters, Todd said.

"I can see where it might be possible, [five to eight] years down the road," Todd, the eight generation of his family to make a living off the water. "I don't think aquaculture is a replacement to the public fishery, but I think it could help smooth out the bumps."

This report was made possible through a fellowship at the Institute for Journalism and Natural Resources.