‘A Lot of Uncertainty’: Spread of Deadly Disease in PEI Oysters Under Investigation

Oysters harvested from a farm are inspected by a worker in Brunswick, Maine, on June 12, 2022 (THE CANADIAN PRESS/AP, Robert F. Bukaty)

Oyster farmers in Prince Edward Island are facing uncertain times as three more areas of the island have tested positive for the presence of a deadly parasite that could threaten the industry.

P.E.I.’s oyster farming industry has been placed under restrictions to curb the spread of multinuclear sphere X, or MSX, a disease first detected in oyster samples earlier this month that increases mortality and stunts growth in the mollusks.

The parasite has now been detected in four areas of the island in total, and farmers are awaiting information from the Canadian Food Inspection Agency (CFIA) to determine the rate of spread and the safest way to continue production.

“There is a lot of uncertainty in terms of where the MSX has spread to,” Peter Warris, executive director of the P.E.I Aquaculture Alliance, told The Epoch Times. “Everyone’s been very careful and adapting to the new situation at the moment.”

Infected Areas

The first case of MSX in P.E.I was confirmed on July 13, 2024, when the CFIA detected the parasite in oyster samples in Bedeque Bay. Six days later, the area in and around the community was declared a primary control zone, authorities said in a July 20 press release, meaning that animals or objects at risk of contamination could only be moved in and out of the area with a permit from the CFIA.

On July 23, authorities confirmed the presence of the parasite in three more areas and declared them primary control zones. The new infected zones include an area in Boughton River, an area in Southwest River/New London Bay, and an area between Lennox Island and Black Banks.

This parasite was previously detected in Nova Scotia and British Columbia. This is the first case of MSX in P.E.I.

MSX can increase mortality rates in oysters by up to 95 percent. It also impedes new shell growth and makes oysters thin and watery. The disease does not pose a risk to human health, according to the CFIA.

The complete life cycle of the parasite is not known, nor how it spreads among mollusks. There are no treatment options available, says the CFIA, so spread control is based on measures such as cleaning and disinfection, monitoring the movements of infected animals, or humanely killing them.

Still Safe to Eat

The P.E.I oyster industry has an estimated landed value of over $24 million, according to a 2023 government report. The island accounts for 26 percent of Canadian oyster production and 74 percent of Atlantic Canada oyster production, according to estimates from P.E.I’s Department of Fisheries, Tourism, Sport and Culture.

In 2019, the island provided 31.7 percent ($54.24 million) of the economic value of oysters in Canada, according to provincial data, establishing itself as one of Canada’s top oyster producers, second only to B.C. and followed by New Brunswick.

Mr. Warris says he remains hopeful that the industry will not be negatively affected, adding that it is not uncommon to grow oysters in MSX-positive regions, as is done in places such as Maine in the U.S.

“I would like to highlight that the oysters themselves are perfectly safe to eat,” he said. “There is absolutely nothing wrong with P.E.I oysters just because of this unfortunate incident.”

He says one way the public can help islanders in these times of uncertainty is to “keep eating P.E.I oysters.”