Darnley Basin is 5th P.E.I. waterway to test positive for oyster disease, says CFIA
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This article was written by Stephen Brun and originally published by CBC News on August 13, 2024 at 7:13PM ADT. We are sharing the full text here for reference. All rights remain with the original publisher.
Presumptive positive test result for MSX also found in Percival River

Primary control zones have been put in place in five P.E.I. waterways to date. (Julien Lecacheur/Radio-Canada)
Another waterway on Prince Edward Island has now tested positive for the presence of a disease that affects oysters, the Canadian Food Inspection Agency says.
In an interview with CBC’s Steve Bruce on Tuesday, the CFIA’s incident commander Kathy Brewer-Dalton said a primary control zone has been put in place in Darnley Basin, on P.E.I.’s North Shore.
It’s the fifth area on the Island to yield positive test results for the presence multinuclear sphere X, or MSX, in the past six weeks.
Brewer-Dalton said one other river near Alaska, in western P.E.I., has also returned a presumptive positive test result for MSX that will need to be confirmed through DNA sequencing in the coming days.
“We do have presumptive positives in the Percival River area, so those have been sent off for sequencing and we’re awaiting those results,” she said. “So depending on the results of that sequencing there may be an additional PCZ, or primary control zone, put in place.”
MSX was first detected in Bedeque Bay on July 11, but it has since been confirmed in several areas throughout the province.
While harmless to humans, MSX can cause mortality of 80 to 90 per cent when it strikes a new population of oysters.
The CFIA puts primary control zones in place to control the movement of oysters and equipment in and out of the affected areas. Oysters can still be harvested and sent to market with a permit from the agency.
The disease comes with a lot of uncertainty for P.E.I.’s multimillion-dollar oyster industry.
MSX wiped out oyster stocks in Chesapeake Bay, between Maryland and Delaware, in the 1950s. It had never been spotted north of Maine until 2002 when it was detected in Cape Breton — where it has affected the industry ever since.

The parasite can stunt the growth of oysters and kill many of them. (Julien Lecacheur/Radio-Canada)
“I cannot say enough about the industry members — the wild harvesters, the aquaculture producers and the processors. They have been committed to this response right off the get-go with the CFIA and that has made a huge difference in the strides that we’ve made over the last six weeks, so I really want to give them a lot of credit,” Brewer-Dalton said.
She said the CFIA has issued around 120 permits for the movement of oysters to and from primary control zones to date.
Tusday, the federal government announced it would contribute up to $1 million over the next two years to “to support scientific research towards addressing knowledge gaps in our understanding of MSX.”
Ottawa also announced that a science summit will happen this fall, which will gather experts and partners to discuss what is known about the disease, as well as identify priority areas for additional research.
Going forward, the agency will complete sampling and testing from P.E.I. waterways to determine the extent of the infection in the province. Depending on the results, the primary control zones could remain, or the CFIA may declare “infected zones,” similar to what’s currently in place in Cape Breton.
Brewer-Dalton understands that people who rely on the oysters for their livelihood are hungry for answers, but assured the industry that the CFIA has regional and national crisis teams dedicated solely to the MSX issue.
“Once we get through the sampling and understand the extent of the infection, then we’re on to the next step to say OK, now that we know where the infection is, where do we go from here? How do we manage this disease from the ground, how do we manage within it?”
Source: CBC News. Original article available here.
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