A Multitude of Oysters? Looks Can Be Deceiving Watching a professional shuck oysters is hypnotic. With thick-gloved hands, he steadies the mollusk on a cushion of cloth stained with gray juice and grit. Next he drives a stubby blade into the valve that separates the two shells, wiggling it to slice through the muscle that clamps them shut. Then he jerks the oyster open, and the scent of salt and sea wafts through the air. Finally, with a flick of his wrist, the shucker flings away the flat side of the shell and inspects the meat encased in the remaining half. If it's good, it is added to a tray that will be hurried out to hungry customers. They may add a dash of lemon and hot sauce before gulping down each glistening blob. It's an industry that ticks along like a metronome in New Orleans, where I recently spent a long weekend. Restaurants in the French Quarter were full every night of my stay, and part of the draw was the oyster harvest, which began in early October. With roughly two million acres of public and private oyster beds and annual revenue of $350 million, Louisiana's oyster industry is the largest in the United States. New Orleans prides itself on being the "oyster capital" and has devised endless ways to prepare the delicacy -- pannéed, broiled or baked; in sandwiches, stews or pies; or most traditionally, raw on the half shell. Still, the industry has yet to bounce back from recent calamities that took a heavy toll on the state's coastal estuaries, where freshwater meets seawater and oysters form part of the ecosystem's bedrock. "The word I would use for recovery is that it's 'beginning,' " said John Supan, an oyster specialist at Louisiana State University who is the director of the Sea Grant Grand Isle oyster hatchery. In 2005, Hurricane Katrina upended vast networks of reefs along the Gulf Coast. Then came the Deepwater Horizon spill of 2010, which sent oil coursing through the marshes. Oyster beds were disrupted again in late August of this year by the gales and pounding rains of Hurricane Isaac, which sowed muck that impeded the seasonal start of production. Sal Sunseri, sales manager at the P&J Oyster Company in New Orleans, the oldest shucking operation in the United States, said that while business has gradually been improving since the 2010 spill, the company is still at only 35 percent of its normal production - and the company has yet to resume shucking its own oysters. Still, it's hard to fully quantify the impacts of storms and spills because the estuarine oyster beds go through natural dips and surges of their own. Louisiana's seem to be undergoing a natural recession at the moment, so "it's hard to say what the man-made impact is, superimposed over the tremendous variation that exists naturally," said Thomas Soniat, a biology professor at the University of New Orleans. It's particularly difficult to measure the impact of the oil that sullied the estuaries in 2010 and the tar balls that return during major storms in the gulf region. One ecological shock that scientists target with more confidence is the freshwater diversion of 2010, when Gov. Bobby Jindall ordered the opening of giant valves to pump freshwater into the Mississippi in an effort to force out some of the oil that was seeping in. The diversion severely damaged the oyster beds, which thrive only in a delicate balance of saltwater and fresh. Mr. Sunseri of P&J Oyster said there was no question that the torrents of freshwater damaged his business. "The approach of an oysterman is to create smaller diversions that replicate the way it used to be -- not these big major diversions that change the environment," he said. Dr. Soniat said the mortality rate was 98 percent in some oyster beds. Adding to the challenge of recovery, the waves unleashed by Hurricane Isaac churned up marshlands, causing them to release what is known as overburden, an influx of loosened marsh grasses that is then cast atop the reefs. Uprooted, the vegetation rots and bacteria then thrive, sapping the estuarine water of oxygen and effectively suffocating the oysters. The only solution is dredging. "The challenge is to get out there and clean the reef as well as you can," said Dr. Supan, the Louisiana State researcher. By "raking" the reefs, the dredgers free oysters from this toxic soup by turning them over "like you're plowing a field," he said. Ultimately, the most prudent strategy is active reef management, Dr. Supan said. Traditionally, oyster production in the gulf allowed nature to take its course. But other avenues have recently proved attractive. Really, when you're managing oyster resources, there are two words: 'plant cultch,' he said. Cultch is a mass of shells, pebbles and gravel; by spreading it on the estuary floor, workers can create a substrate for the oysters to latch onto so they can then cluster to form underwater fortresses. The Louisiana Department of Wildlife and Fisheries has its own Oyster Cultch Project under way in six estuarine environments across the state, from Sister Lake to Three Mile Bay. By simultaneously building hatcheries where oyster larvae are cultivated, the state hopes to seed the new reefs with generations of oysters that will build new fortresses. Back in the restaurant in New Orleans where I was lulled by the shucking routine, the piles of oysters teetering atop trays make it hard to absorb the reality that gulf oysters are not yet thriving the way they used to. The shucker tapped his knife in front of me, sending a tiny round object rolling my way. "A pearl for the girl," he joked. Its shape was rather irregular and it was not exactly lustrous, but to me it was a remarkable thing. Maybe the enduring oyster itself, which slips so smoothly down millions of throats, ought to be regarded as a kind of treasure, too.