June 30, 2017

Nova Scotia makes progress in reviving oyster farming

A professor-researcher at Canada's Dalhousie University Faculty of Agriculture is leading a team of researchers in helping to revive Cape Breton's oyster sector, which used to be thriving until 2002, when a pathogen was found in oysters at the Bras D'Ors Lake. Cape Breton is an island at the eastern end of Nova Scotia province in Canada.

The disease, known as the Haplosporidium nelsonii parasite (MSX), causes high mortality in oyster populations but has no impact on humans, according to a news feature posted on Dalhousie University's website.

"This parasite impacted Cape Breton's wild oyster fishery, oyster aquaculture, and First Nations access to the oyster populations that they have been connected with throughout their history," said Dr. Sarah Stewart-Clark, an assistant professor at the agriculture faculty's department of animal science and aquaculture who is determined to rebuild what is recognized as a "100-year-old economic and cultural activity".

Dr. Stewart-Clark and her team have been responsible for leading a component of a project started three years ago by the Aquaculture Association of Nova Scotia to help fix the damage the disease outbreak had caused, prevent the disease from spreading, and eventually make the oyster sector in Nova Scotia successful in the long term.

Dr. Stewart-Clark and her team have so far discovered genetic markers from the oysters that have survived the outbreak in the Bras D'Ors Lake. They hope to use the genetic markers discovered to generate oysters that are resistant to the MSX parasite.

"There is always the possibility that the MSX parasite will eventually spread across Atlantic Canada, and if that occurs, having a resistant strain of oysters would save these sectors from collapse," Dr. Stewart-Clark said.

Her group has also developed hatchery and nursery SOPs so that the industry can have science-based data to optimise the production and survival of oyster larvae in hatchery settings.