Pearls of wisdom: Unhinging facts about oysters

V. Todd Miller

“He was a bold man that first ate an oyster,” said 18th-century Irish satirist Jonathan Swift. Whether enjoyed fried, grilled, in a seafood gumbo or, perhaps most opinion dividing, raw, there is no denying the oyster’s impact on both Louisiana’s culture and seafood industry.

Oysters have been consumed by humans for thousands of years. Wealthy Greeks and Romans thought of them as a delicacy and an aphrodisiac. While the former is still true in many cultures, the latter is more debatable.

Oysters are high in zinc, with six medium-sized ones providing 32 milligrams or 291% of the daily value, according to Healthline.com. Studies have shown that zinc is important to testosterone production in males, which would lend credence to the aphrodisiac theory, but it isn’t fully known if that is the actual reason for the long-held belief.

Another oyster claim is that they are alive until shucked. Megan La Peyre, a researcher in the LSU AgCenter School of Renewable Natural Resources, said this isn’t quite accurate.

“They are alive even after they are shucked,” she said. “If you eat them immediately after shucking, you are eating them live. And if you look carefully, you can see their heartbeat.”

One adage that many agree on is that oysters should not be consumed in months that don’t contain the letter “r” in their names. This idea likely dates back to 1599 when it appeared in an English cookbook, according to a New York Times article written in 2017 by science journalist Joanna Klein. There is merit to this, said AgCenter and Louisiana Sea Grant food safety specialist Evelyn Watts.

“We know that vibrio is more prevalent in warmer months,” Watts said. “But the fact is vibrio can occur at any time of the year, and eating raw or undercooked oysters always presents a foodborne risk.”

According to the Center for Disease Control and Prevention, vibrio is bacteria that lives in coastal waters and is present in higher concentrations between May and October when the water is warmer. It causes vibriosis, which the CDC estimates causes 80,000 illnesses and 100 deaths in the United States annually.

In addition to the greater risk of contracting vibrio, oysters are simply less appetizing in warmer months, which is when they spawn, La Peyre said.

“Oysters reproduce in the warmer months, so they are full of gametes,” she said, “while in the winter, they are ‘fat’ and growing and tend to be sweeter.”

Former oyster fisherman and current soft-shell crab producer Daniel Edgar, of Franklin, said refrigeration techniques have aided in oysters being consumed year-round in many coastal regions, where they don’t have to travel as far to market.

“Way back when, oyster harvesters didn’t have to keep a cooler on their boat,” Edgar said. “Today, any boat that spends the night offshore or the boats that fish far away, like south of Marsh Island, have to keep one on board. This was legislated to better protect the consumer.”

Edgar also said farm-raised oysters are easier to produce now than perhaps ever before with the right setup. Essentially all that is needed is enough brackish water and room to grow.

“There’s a guy in Grand Isle that sells oyster spats,” he said. “If you put 500 in a box when they’re young, in about a month they won’t fit in that box anymore, so you’ll have to divide them up into boxes of 250 and so on.”

Edgar and today’s oyster fishermen owe a lot to those credited with developing the commercial oyster industry in Louisiana: Croatian immigrants. LSU English professor Carolyn Ware, who specializes in folklife, wrote in Folklife in Louisiana about the history of Croatians in the state.

“Many of Louisiana’s Croatian men continue to fish oysters, and some are third- or fourth-generation oystermen,” Ware wrote. “Sons often start fishing with fathers on weekends and summers as children. As adults, they frequently still fish on the acres once leased by their fathers.”

Things have changed a great deal economically from those early days. AgCenter and Louisiana Sea Grant economist Rex Caffey said oysters are the third-most lucrative seafood crop in the state, behind only shrimp and menhaden, which generally aren’t fit for human consumption and are used primarily for fertilizer, animal food and as bait for blue crab.

“Recently, oysters and crabs have switched places from year to year in terms of total value,” Caffey said. “But in 2018, nearly $76 million worth of Gulf oysters were harvested in the state.”