I leave Fauchier's and wander through the dense maze of cabanes, a century of oyster shells crunching underfoot, until I reach the place where I'm staying, the Hôtel de la Plage. The hotel and its restaurant, Chez Magne, hark back to the creaky seaside boardinghouses and steamy seafood diners that were once everywhere on this coast but have become increasingly rare since the 1960s. The places of that kind that remain are wildly popular with everyone from blue-blooded Bordelais to Arcachon fishermen.

At Chez Magne, a meal begins with oysters, of course—raw, baked with butter, or served with grilled pork sausages, a classic combination in the region. After that, the fishermen's soup is a good choice. Chez Magne's version contains little more than fish and potatoes thickened with garlic paste and egg yolk and garnished with croutons and grated gruyère. Fish-belly gray and homely as oatmeal, it nonetheless evokes the fresh, mild scent and flavor of the catch of the day.

Chez Magne may be the landmark restaurant in L'Herbe, but the local culinary celebrity is chef Philippe Téchoire, who was born and raised in the oyster village of Le Canon—just up the beach from L'Herbe—and who currently presides over two restaurants in Bordeaux, Chez Philippe and Philippe Chez Dubern. Téchoire trained at his mother's now defunct restaurant in Le Canon, Chez Irène, and he obviously learned his lessons well. At a small gathering one afternoon at the home of one of his cousins in Le Canon, he expands my knowledge of regional delicacies. His stuffed oysters, flash-roasted with bread crumbs, butter, and garlic until they pop, leave me wiping my chin and asking for more. His oyster fritters are meltingly tender, their coating surprisingly airy. Noticing that he makes a point of tipping out the seawater as he opens each oyster, I gasp. Why would he want to get rid of that precious juice? "That's just the brine," he says, laughing. "You must pour that off. Then the oyster exudes its own juice. That is the best liquid. That you must preserve."

On the last evening of my stay in Arcachon, I stop by Fauchier's cabane for a glass of rosé and some more oyster talk. About ten oystermen are still based in L'Herbe and all seem to be doing well, Fauchier tells me, but things are changing. Cabanes are coveted real estate; if one is put up for sale and an oysterman doesn't buy it, by law it must go on the open market, and that is happening more often. Then there is the increasing number of environmental hazards. As the Saint-Tropez of western France, Cap Ferret grows more popular with the yacht set every year. In high season, the bay seethes with noisy and oily pleasure craft that often scrape their hulls on the racked oysters. And the 2002 oil spill from the tanker Prestige, which sank nearby, threatened to snuff out Arcachon's oyster industry altogether. Oyster sales were banned for two weeks until the waters were given a clean bill of health.

Despite these issues, not to mention the long, ever changing hours, there are many reasons Fauchier still loves his métier. "It's the sea, the surroundings," he says. "And it's the nurturing of baby oysters. You seed them, you raise them. We are gardeners. When you put a little plant into the ground, you get a beautiful flower. It's the same for us."

Fauchier does admit, however, that as he ages he dreams of scaling down to minimum production and having a simple oyster stand behind his cabane where he can serve passersby. "A glass of wine, a chunk of bread, butter, lemon, and a dozen oysters," he says. "That's what it's all about."