Maritime oyster mission hopes to crack open solution to devastating disease

HALIFAX – Eleven years after a fatal disease damaged Nova Scotia’s oyster industry, a maritime delegation is travelling to the United States to learn how New England’s aquaculture industry was so successfully revitalized.

The aquaculture associations of both Nova Scotia and Prince Edward Island are leading a group of about 16 researchers, industry delegates and government officials to Maine, Massachusetts and Rhode Island for a week-long visit to discuss technology and policy approaches to battle MSX disease.

“Basically it’s a mission to go down and see how the oyster farmers in New England are managing to operate what seems to be successful businesses in the presence of MSX disease,” said Bruce Hancock, executive director of the Nova Scotia Aquaculture Association.

MSX is caused by a microscopic parasite and stands for Multinucleate Sphere X, which the disease was called when first discovered in Chesapeake Bay American (or Eastern) oysters in the late 1950s.

It was not until 2002 that the disease was detected in the Maritimes, where it decimated the oyster industry in the Bras d’Or Lakes of Cape Breton, cutting the province’s oyster production in half in a single year.

“In Nova Scotia we lost probably about 50 per cent of our oyster industry,” said Hancock. “It’s been 11 years since (then) and what we’d like to do is to see if there’s a way that we could try to rebuild the industry.”

Hancock estimated the economic impact of MSX in Atlantic Canada to be about $1 million per year.

The disease itself is not fully understood, said Hancock, including the vector by which MSX is spread.

The parasite works its way through an oyster’s soft tissues, slowly weakening the animal over the course of a year or two until it dies.

But MSX is only a health problem for oysters and has no effect on human health, according to the Department of Fisheries and Oceans Canada.

“There are a lot of unknowns but what we do know is down in the States where they have had a history of MSX they’re finding ways of working around the disease,” said Hancock.

New England has developed methods of raising disease-resistant oyster strains from hatcheries and has put in place government regulations that have prevented MSX from spreading to unaffected areas.

The eastern American seaboard has also developed systems to grow their oysters more quickly in suspension, as well as triploid genetic varieties that are sterile and therefore channel energy into growth that would otherwise be spent on reproduction.

“It’s not that the oysters they’re producing would never get MSX, it’s just that they grow faster and they’re a little bit more resistant to it, so you can get them up to market size before MSX gets itself established and the oyster can’t live any longer,” he said.

There is also a role for rules and regulations, said Hancock.

“This isn’t necessarily about government assistance or anything like that,” he said. “This is about government learning about how they’re regulating in the States so they can both move the industry forward but at the same time make sure that there’s no further spread of the disease.”

Hancock said the delegation will include industry representatives from Nova Scotia and Prince Edward Island, as well as representatives from those provinces’ aquaculture associations.

“A couple people are going from the Canadian Food Inspection Agency,” said Hancock, “which is really nice to see.”

A representative from each of the maritime provinces will also be in attendence, though Nova Scotia is the only maritime province in which MSX has so far been detected.

“The ultimate (desired) result is that we can start rebuilding the oyster industry in MSX-positive areas,” said Hancock. “That’s what i want to see.”