Research breathes new life into possible return of Cape Breton oyster industry

A Cape Breton University biologist says a local oyster industry could be viable again one day soon, a couple of decades after it was nearly wiped out by a parasite.

Rod Beresford has been doing research on ways to grow oysters that would not be killed off by the microscopic MSX parasite. He said after two years of research, the results are promising.

Oysters are traditionally grown in beds near the sea floor, but Beresford has been experimenting with floating cages and found there are productive areas in the Bras d'Or Lake.

"Not only are we seeing great survival with those oysters out of the surface cages, but there's also really significant growth," he told CBC's Information Morning Cape Breton. "Much more growth than we expected, to the point that in some locations where we had the oysters split among two cages, we've had to add a third cage."

The parasite is still present in the water near the surface, but it seems to be less prevalent.

It is unclear why that is, but Beresford has a couple of summer students and another field season this year to investigate and is working on some hypotheses.

"Temperature changes, salinity changes on a daily basis, or even an hourly basis for that matter, that's a pretty tough space to live in," Beresford said.

"So we think it's conducive for oyster growth and oyster survival, but not so good for the parasite."

Results so far have been site specific, though, he said, with oysters at some locations still dying in large numbers, even near the surface.

Still, mortality rates at other sites are equivalent to what would normally be expected through traditional farming methods, leading to excitement and the possibility of an industry renewal.

MSX not harmful to humans

"For the first time in about 20 years, there's actually oysters large enough in the Bras d'Or to sell," Beresford said.

MSX does not harm humans, but it kills oysters.

Oyster farming is a $4-billion global industry, Beresford said, and rural Cape Breton could use the economic boost.

Beresford and his team are now working with researchers at Dalhousie University in Halifax to develop a rapid test so growers can detect parasites in the field.

One would detect MSX and another would detect a parasite that is not currently in Canadian waters, but could easily migrate north from the U.S.

Tests currently require DNA samples that have to go to a laboratory and take a couple of days to process.

Growers or processors need a test they can administer themselves, quickly and easily, Beresford said.

"If all works well, within a matter of two to three hours, you could give them an answer, that you do have the parasite or the prevalence is high," he said.

"It's just another tool in the box that we'd have to help this industry get back on its feet."

Potlotek First Nation has an oyster processing facility on the Bras d'Or Lake and a rapid test would help them get their product to market much quicker.

An easy and inexpensive rapid test also means growers and processors can take control of the process, rather than relying on scientists with laboratories and equipment.

"This is done right out of the trunk of a car or the back of a pickup truck, so it's one of these things that once we have it working, we can hand this technology over to growers and then they can do it themselves," Beresford said.

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