For almost 20 years, Houstonians have learned to depend on Robb Walsh’s articulate enthusiasm for food, particularly Texas food. We’re not talking fancy—Walsh writes about roadside barbecue, venerable Tex-Mex, sandwiches wrapped in greasy paper, the beautiful varieties of hot sauce and chile peppers. As the food writer for the Houston Press, Walsh surveys the wild array of Cajun, Asian, African, and Caribbean cafes that seem to pop up every other week.

Walsh is a natural storyteller when it comes to unearthing Texas delicacies, but his new book, devoted to his obsession with the many varieties of growing, harvesting and consuming of oysters, is more personal than his other work and takes him way outside Harris County. He begins his study of the bi-valve riding on a diesel-powered oyster boat in Galveston Bay, on a winter day when the water temperature is 60 degrees. He calls it perfect oyster weather. The boat belongs to Walsh’s friend, Misho Ivic, and is named the Trpanj after his home village in Croatia. As the diesel engine roars, the Trpanj‘s dredge scrapes the bay’s bottom. Detritus and smaller oysters are thrown back into the water.

Walsh eats an oyster just brought up (briny, a little metallic and surprisingly sweet) and addresses the bad reputation of Gulf oysters in general and Galveston Bay oysters in particular.

“East Coast and West Coast oystermen say that the waters of the Gulf of Mexico are filthy. And maybe they are. But oysters live in brackish water in freshwater estuaries, not in the Gulf of Mexico. And the scientists I interviewed said that Galveston Bay was in pretty good shape.”

Conscientious fishermen like Ivic have no interest in selling tainted oysters, and adhere to a fishing-zone system enforced by coastal game wardens. Reefs close to the shore are off limits because of wastewater and runoff from lawns and cow pastures. Do not, Walsh says, be alarmed by the muddy brown color of the water—fisherman say it is full of plankton and other goodies that make oysters and crabs thrive.

What makes the eater of raw oysters sick is the bacterium vibio cholorae, which grows in warm polluted water. If you have ever eaten a “bad oyster,” you know the symptoms that feel like food poisoning, only worse—it can even lead to cholera. Raw oysters are a seasonal food, especially in hot climates and anyone tempted to eat Galveston or Gulf oysters in August will not do so after reading Walsh.

The quality of Texas oysters is lost on much of the country. Walsh is robustly attacked for being an oyster writer from Houston when he visits New England and the West Coast, particularly San Francisco. There he meets an egomaniac oyster entrepreneur named Billy Martinelli, who greets Walsh by saying, “Gulf oysters are criminal.” Walsh manages to change the subject and in a few days accompanies Martinelli to an oyster picnic on Hog Island in Tomales Bay, on the coast west of Sonoma County.

Like this idyllic Northern California scene, much of Sex, Death, and Oysters is a travelogue punctuated with shellfish. Walsh goes to New Orleans, before and after Katrina, to visit famous eateries like the Acme Oyster House and Felix’s Oyster Bar in the French Quarter and Casamento’s on Magazine Street. On a trip with his wife and daughters, Walsh makes it onto the Acme’s wall of fame by eating 180 oysters in two hours. The only aftereffect he reports is an audible sloshing noise as he walks up Iberville Street.

Before the hurricane, Louisiana had by far the most productive oyster beds in the country. Katrina destroyed more than 50 percent of the oyster beds in the estuaries and most of the piers and oyster boats in places like Plaquemines Parish and Grand Isle. Walsh meets Cajun and Croatian oystermen on Grand Isle, who all pointed out that after major storms there is a frenzy of reproduction among oyster seedlings (this is part of the sex in the title). After three years or so, production is back up. It remains to be seen whether that happens in Galveston Bay after Hurricane Ike.

Not everyone loves oysters, a fact that’s reflected in Walsh’s trip to England, where he visits Colchester, in Essex County, northeast of London. Planning the English leg of his international oyster survey, Walsh had trouble finding out anything about the Colchester Oyster Festival, an annual event since 1618. When he arrives, he discovers why—no one in the town actually eats oysters from the beds that fed the ancient Romans. He learns that the famous oyster banquet, presided over by Colchester’s mayor, is an anachronistically formal event. The 200 or so guests are seated according to social rank inside a room that looks “like a cross between a ballroom at the Waldorf Astoria and the inside of a cathedral.” Walsh manages to get a cheap media seat. When he notices that more than half the guests don’t touch the delicious Colchester oysters, he grabs a couple of plates and some bread and butter. He joins two elderly nurses drinking tea at a first aid table. “When they noticed the oysters, they were horrified. One said she had never seen an oyster before, never mind eaten one. She looked at mine and declared them disgusting.”

After some successful oystering in London, Walsh describes Christmas in Paris with his wife, Kelly, on their honeymoon in 2005. They had planned this trip after their wedding six months earlier, Walsh knowing the holidays are the height of the oyster season in Paris—but what bride could refuse a wedding trip to the city of lights? The only hitch is that Kelly is now pregnant, has raging morning sickness, and an opened-up oyster makes her gorge rise. The trip also coincides with a serious snowstorm that becomes a blizzard. The intrepid shellfish journalist fulfills his mission in one famous oyster restaurant (Le Dome) and one hidden little place (Brasserie Flo), and finds Kelly the best puff pastry dessert in the city, demonstrating that he does have some common sense.

Back home, Robb and Kelly start serving big quantities of oysters at their Super Bowl parties. He gives instructions on how to shuck them without destroying your hands. We learn that some of his travels have paid off. Walsh reports that during the winter months, when it is too cold for Canadian oysters, Rodney’s Oyster House in Toronto, run by his friend Rodney Clark, runs a special on Galveston Bay oysters. Rodney’s is among the 25 eating places Walsh recommends, and the book is full of recipes for dishes like oyster and artichoke soup.

Sex, Death, and Oysters was a labor of love, written while Walsh was working on other projects, including his fine study of our native hybrid food, The Tex Mex Cookbook. He understands the reluctance of some eaters to ingest the mysterious fruits de mer that can kill you, and in explaining the attraction Walsh fully reveals himself to be a sensualist as well as a gourmand:

Eating raw oysters is at once perverse and spiritual. A freshly shucked oyster enters your mouth while it is still alive and dies while giving you pleasure. As I savored the wonderfully slick texture, delicate briny flavor, and marine aroma, it was easy to see how oysters came to be associated with the tenderest portion of the female anatomy.

Dick Holland teaches in the Liberal Arts Honors Program at the University of Texas at Austin. His Spring 2010 class is titled “The Texas State of Mind.”