Next steps critical in P.E.I. oyster industry's fight against MSX, says CFIA

With a parasite deadly to oysters highly likely to be present in most P.E.I. waterways soon if it isn't already, the Canadian Food Inspection Agency says deciding what to do next about the crisis is crucial.

CFIA officials gave provincial politicians an update on the ongoing battle against multinuclear sphere X, or MSX, during a legislative standing committee meeting on Thursday. 

The first discovery of the parasite was confirmed in July, after analysis of samples from Bedeque Bay, but the agency officials said they can't pinpoint the outbreak to just one area. 

"We're finding it in places with no link to Bedeque at all. Actually, our latest suspect positive is in an area where there's only a few people that actually fish," said Dr. Danielle Williams, the CFIA's Atlantic region veterinary officer. 

"It's kind of telling, when you have these areas that have no direct link to the first outbreak, that we're not dealing with something that came into one particular spot and spread out.

"We're dealing with something that either came in multiple ways or has been in the water for a while and just needed to circulate around."

MSX will have no impact on a person who eats an oyster containing it, but the parasite tends to kill oysters before they are ready to harvest, dramatically reducing yields in a waterway.

Following the Bedeque Bay discovery, the parasite was also found in Boughton River and a stretch of the North Shore west of Malpeque Bay, and then in Darnley Bay in August.  

There were new detections in late September in East River, Malpeque Bay and Rustico.

The areas with confirmed positive tests for MSX are now what the CFIA calls primary control zones, or PCZs. You can't move oysters and equipment from within those zones to another waterway, and you can't harvest oysters from the zones without a permit from the CFIA. 

The question now becomes what to do next. 

More PCZs could be created, but the permitting process and red tape required for that plan could be difficult for the oyster industry to manage on a day-to-day basis.

The other option would be to declare the entire Island an infected zone in what the CFIA calls a domestic movement control program. 

Kathy Brewer-Dalton, the agency's director general of Atlantic operations, told the legislative committee that this option could actually make it easier for harvesters. 

In that case, fishers would need a permit only if they want to move oysters out of declared areas, and there would be no need for the rigorous sanitation measures for boats and equipment that are currently in place. 

"It is very difficult for us to be on the ground, on the water 24/7," Brewer-Dalton said. "There's a lot of activity, particularly with the wild harvest being open mid-September."

Hope for some MSX resistance

This time of year is a crucial stage for the harvest as it relates to MSX. 

Oyster populations build up resistance to the parasite over time, and that process can be accelerated by importing and farming oyster spat from areas where it has become endemic. Maine had success with this strategy when MSX arrived off its shores in 2002.

Williams said the CFIA hasn't seen a spike in mortality yet, but the parasite often "flips the switch" late in the year as the oysters grow to maturity.   

"This is the time of year when we hold our breath because it's usually October-November where you really start to see increases in mortality numbers due to MSX," she said. 

"Once we get a little bit further along in this, then we'll see if there's some resistance in the oysters that are present there. Maybe there is; I'm hopeful there is."