With more than 200 reported cases of norovirus linked to British Columbia oysters — which account for roughly 60 per cent of the oysters consumed in Canada — Maritimes oyster producers are struggling to keep up with demand.

"There is a tremendous hunger for oysters across the world — from Asia and Europe to the United States and Canada," said Bay Enterprises owner Charles Purdy of Malagash, N.S.  

British Columbia has had a big share of the business in recent years, but "that changed last year, with a very big demand," Purdy said.

"We've been trying very hard to meet it."

Elaborate safety protocols

Problems with Pacific oysters have intensified efforts by producers in Nova Scotia, New Brunswick, and P.E.I. — where the oysters are different from those farmed on the West Coast — to ensure the product reaches consumers safely, Purdy said.

Usually, oysters become tainted with norovirus because of contact with untreated sewage, but the investigation has yet to prove the exact cause of the current outbreak.

At Bay Enterprises in Nova Scotia, "we have a lot of protocols in place," he said.

"Our harvest is more elaborate than some. We start the cooling process immediately as soon as the shellfish come out of the water."

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Oysters can become contaminated with norovirus as a result of raw sewage in the water. In Nova Scotia, the shellfish are cooled as soon as they leave the water. ((Ted S. Warren/Associated Press))

The shellfish are then moved quickly into the processing plant and cooled to 4 C or below, "which puts them into a hibernation state," Purdy said.

Once closed, "it takes a lot of pressure to open them," he said. "Then once they leave our plants, they are in sealed containers, so everything should be all right right down to the end user."

Purdy said systems for determining where an oyster originates are also becoming more sophisticated, and that could help contain problems more quickly in the future.

"Oysters can be tracked at the DNA level now," he said. "You can take a DNA sample from an oyster at a restaurant and trace it back to the body of water it came out of. But it's a lot of sampling and a lot of cost."

Nature's superfood — if safe

Increased interest in a local product is never a bad thing, Purdy said, and judging by the demand, more people are interested in eating the shellfish.

"People are very health-conscious now, and they like an experience. And an oyster gives you that, as well as the micro-nutrients and a boost to the system."

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Oysters are both delicious and one of nature's super-foods - as long as they're kept safe, points out Nova Scotia oyster farmer Charles Purdy. (Credit: iStock/Getty Images)

But outbreaks of contamination are bad news for the entire oyster industry — even when they occur on the opposite side of the country.

"We have to keep the product really safe, and that's what everyone's aim is to do," Purdy said. "Anytime someone eats an oyster and gets sick, that's news. That's something that no one who grows oysters anywhere wants to see."

With files from Information Morning Saint John