Oysters are now being grown on land to ensure a safer and more hygienic product. A news article describes how an oyster bar owner in southern Japan has created a farm on land where oysters are grown in tanks of seawater pumped from 2000 feet down in the ocean. The oyster bar owner did this so he could vouch for the safety of the oysters he served, after a norovirus epidemic made people less likely to eat oysters.
As it notes,
Raw oysters can be a source of norovirus and pathogens such as E. coli, often through exposure to untreated sewage—so even when properly handled and stored, they can cause food poisoning. Most production today happens in shallow bays, with the oysters grown on the ocean floor or in cages, trays or floating bags. They’re then bathed in ultraviolet light or pumped full of microbubbles to dislodge impurities. But those methods aren’t 100% foolproof, so pathogens sometimes survive within the oyster’s flesh.
But by raising oysters on land, the farmer, Mr. Yoshida, is giving them a cleaner, more controlled environment. He’s feeding the oysters plankton and algae also grown on land. By doing this, the farmer is eliminating the risk of contamination during cultivation.” A company was created to raise the oysters, and after it announced that a pilot program had been successful, shares of stock in the company surged in value:
They’re up more than 60% this year as investors bet on strong demand from shellfish fans worried about food safety. The project “was a breakthrough,” says Yoshida, who forecasts annual sales of 450,000 land-farmed oysters within three years, still a relatively small share of the 10 million he currently sells. He aims to charge as much as 1,000 yen ($6.89) apiece in his restaurants, about 50% more than the price of conventionally farmed oysters today. “It was a new market waiting to happen,” he says. “One with the possibility of commanding a higher premium.”
Researchers say the move would help the global oyster industry, which analysts value at almost $10 billion a year, by offering an alternative cultivation method as the planet warms. “Water quality is really deteriorating,” says Jasper van Houcke, a professor of aquaculture at HZ University of Applied Sciences in the Netherlands, who’s worked with oyster farms on new cultivation methods. He predicts costs will come down as land-based producers develop better technologies. “I don’t think it will overtake natural farming,” he says, “but it will be an alternative.”
Yoshida’s main challenge has been securing feed cheaply enough to make the operation profitable. An oyster filters about 20 liters (5 gallons) of seawater per hour, sucking out microorganisms to grow, but the deep-sea water the facility uses lacks sufficient nourishment. Buying feed from elsewhere is too costly, he says, so the company produces it in separate tanks, re‑creating nutrients found in the sea—without the pollutants.
General Oyster has been experimenting with adding various nutrients at different stages of growth to see how this affects flavor. Yoshida says he can now cultivate oysters as sweet, creamy and briny as the highest-grade produce harvested from the sea—at less than 1% the cost of buying feed commercially. “We really struggled to bring down feed costs,” he says, “to not burn through too much money.”
Yoshida says he hopes land-based farming will help ensure oysters survive a changing climate. But his primary goal is to prove that those grown in his tanks are safe from food poisoning—and that people will pay extra for that security.
Raising oysters is tricky. Here’s a video on how a Virginia aquaculture farm raises four million oysters for market, at this link. “Ward Oyster Co. is one of the largest cage oyster farms on the East Coast, selling 4 million oysters and tens of millions of larvae each year. But it takes years for oysters to mature, and in that time, a lot can go wrong.”
