B.C.’s heat wave may be to blame for rising number of shellfish poisonings

B.C.'s heat wave may be to blame for rising number of shellfish poisonings
WatchAn oyster impervious to climate change? Scientists are trying to breed one, meanwhile solo shellfish harvesters see spike in sicknesses.

Health officials say they’ve seen a concerning rise in the number of people becoming ill after harvesting their own shellfish and say the recent heatwave is likely to blame.

“In the last 10 days we’ve had 10 illnesses,” said Lorraine McIntyre, food and safety specialist with Environmental Health.

The unprecedented, deadly heatwave killed likely billions of shellfish. The heat, cooking them right in their shells.

But now, there’s another consequence of the heat,

A bacteria called vibrio, which multiplies in warmer weather, is causing people who are harvesting their own shellfish to get sick.

“No one wants diarrhea. You don’t want to start off your camping weekend with that,” said McIntyre.

Vibrio illness kicks in 12-24 hours after eating affected shellfish and causes diarrhea, nausea, cramps, and vomiting.

As a result of the spike in illnesses, the BCCDC is warning solo harvesters to take precautions.

If you are harvesting on your own shellfish, health experts suggest doing your research on the current health and ocean warnings in the area, and only harvest in a receding tide.

“Shellfish that are on a dry beach, the bacterial numbers have probably gone up quite a bit,” said McIntyre.

Then, once you have your haul, experts say to put it on ice right away. Eating self harvest anything is not suggested. Instead, making sure to cook thoroughly (90 seconds at 90 Celcius, or boiling for 5 minutes is a good rule of thumb)

For crab, the BCCDC sugggests not to cook them whole.

“If they have toxins in their gut and you boil them whole, the toxins can leach out into the water and also contaminate the flesh,” said McIntyre.

Raw oysters in restaurants, however, are safe.

“The commercial folks, they have a lot of controls in place. They’ve all been inspected, tested and the commercial industry works really hard to make sure their shellfish is safe for consumption,” said McIntyre.

But even sourcing commercial oysters this year has been a problem.

“Getting oysters consistently can be difficult in the best of times, but obviously what’s happened in the past few weeks it’s been more so,” said Jess James, owner of The Wandering Mollusk, which does pop up shops at Whistlebouy Brewery in Market Square and Sea Cidery in Sidney.

The Wandering Mollusk had their order cut in half for this weekend, with many farmers holding back stock to make sure they’re safe.

James says he got lucky and is likely one of the only shops on the South Island with raw oysters this weekend.

Meanwhile, scientists say, that summer scarcity is the new norm.

“If you go back 20 years, farmers will tell you the average level of mortality was 10 percent, whereas now, farmers are experiencing half their crop dying every year,” said Dr. Tim Green, the Canada research chair with Shellfish Health and Genomics.

Green is leading a team trying to create an impervious oyster — one that can withstand ocean acidification and heatwaves of the future.

“We really think it’s going to take 5-10 years for the industry to receive the benefits of our breeding program,” said Green.

His message to shellfish farmers, for now, is to hang in there.

“Hopefully not too many of them exit the industry. That’s our big fear, that the culture, that stewardship of the environment, that they disappear,” said Green.

For everyone else harvesting shellfish on their own, the BCCDC is reminding everyone to be safe.

If you think you have vibrio illness call 811 or the poison control line at 1-800-567-8911.

Kori SidawayKori Sidaway

Recent Stories

Send us your news tips and videos!