Question Period Note: Oyster Disease

• Our Government understands the importance of protecting the health of Canada's aquatic resources and the multi-billion dollar export market for fish and seafood products.
• The oyster diseases, MSX and Dermo, pose no risks to human health or food safety, but can cause significant mortality of both wild and cultured oysters and therefore impacts both wild harvesters and oyster farmers.
• That is why the Department is collaborating with the Canadian Food Inspection Agency, which is the federal lead on food safety, as well as working with provinces and industry to mitigate the impacts of MSX and Dermo as well as to respond to industry priorities related to these diseases.

General
• Canada’s National Aquatic Animal Health Program, co-delivered by the Canadian Food Inspection Agency (CFIA) and Fisheries and Oceans Canada (DFO), is responsible for preventing the introduction and/or spread of significant diseases of finfish, mollusks, and crustaceans in both wild and farmed aquatic animals.
• CFIA is the lead agency with legislative authority under the federal Health of Animals Act. CFIA is responsible for enforcing regulations governing import and export, disease management, and surveillance activities. DFO provides diagnostic testing services, research support, and scientific advice.
• DFO conducted over 18,000 diagnostic tests for oysters since the confirmed case of Multinucleate sphere unknown (MSX) in Prince Edward Island (PEI) in July 2024 and the first detection of Dermo in Canada in New Brunswick (NB) in November 2024. These efforts supported the CFIA’s decision-making and containment strategies, and the overall response during the outbreak. As of September 2, 2025, the CFIA declared the waters of Eastern Canada (i.e., NB, Newfoundland and Labrador, Nova Scotia, PEI, and Quebec) as areas where both MSX and Dermo are present or very likely to be present. This means that the movement of oysters which are not yet ready for commercial sale for human consumption will be managed according to the CFIA’s Domestic Movement Control Program.
• On May 8, 2026, the Government of Canada announced measures to help PEI growers cover the cost of disease-resistant oyster seed; approved the import of broodstock to develop disease resistant oysters; supported a one time license buy-back for wild oyster harvesters; a plan to develop a comprehensive response strategy; and a Farm Credit Canada customer support program for the oyster sector.

Importing Disease Resistant Oysters
• On Canada’s east coast, DFO issues introductions and transfers (I&T) licenses under the Fishery (General) Regulations to authorize the intentional release and transfer of live aquatic organisms into fish-bearing waters or fish-rearing facilities when the proposed transfer poses low ecological, disease, and genetic risks.
• Risks associated with each movement, including shellfish for aquaculture purposes, are assessed by federal-provincial/territorial I&T Committees, which have representation from DFO and provincial/territorial governments.
• A large oyster aquaculture company based in PEI, with holdings in the Northeast United States (US), has requested to import various life stages of disease resistant oysters from the US given both diseases have been present along the east coast of the US since the 1950s. The company’s intent is to develop a breeding program that would produce MSX/Dermo resistant oysters and have them adapted to current conditions in Atlantic Canada. In line with their respective mandates, CFIA and DFO must each issue authorizations to allow the import and use of the organisms in Canada.
• CFIA completed a risk assessment for the potential diseases associated with such an import. On April 24, 2026, CFIA issued an import permit for broodstock oysters under import conditions including testing requirements and import quarantine procedures. The decision for the import of triploid seed is still pending.
• DFO and the Province of PEI have also assessed potential disease, genetic, and ecological (e.g., aquatic invasive species) risks associated with the proposed import of broodstock and triploid seeds. The PEI I&T Committee recently recommended the introduction of both broodstock and seed, and has outlined the testing and reporting requirements that must be met prior to any transfers.
• The NB I&T Committee has also received applications for use of US broodstock and seed in NB waters and will undertake its review, informed by the work completed in PEI but incorporating NB specific considerations.
• It is uncertain whether oysters adapted to MSX and Dermo in the US would adapt well to local conditions (e.g., temperatures).

MSX
• MSX is a disease in oysters caused by the parasite Haplosporidium nelsoni. It is a serious disease that can cause significant mortality of both cultured and wild oysters.
• In Canada, the disease was first detected in Bras d’Or Lake, Nova Scotia in 2001, and more recently found in the waters of PEI in June 2024, Since then, it has been found in Quebec, NB, Nova Scotia and Island of Newfoundland.
• Increasingly significant mortalities have been reported in farmed or wild populations at some infected sites in PEI. There are concerns mortalities may continue to expand into new areas, especially since MSX can be dormant or suppressed for long periods of time.

Dermo
• Dermo is a disease in oysters caused by the parasite Perkinsus marinus. It is a serious disease that can cause significant mortality of both cultured and wild oysters.
• Based on tests conducted at DFO’s aquatic animal health laboratory in Moncton, CFIA confirmed a detection of Dermo disease in NB on November 19, 2024. Since then, Dermo has been detected in PEI, Nova Scotia, Quebec, and the Island of Newfoundland.
• These were the first detections in Canada. Consequently CFIA notified the World Organization for Animal Health.

If pressed on measures being taken to limit the spread and impact of MSX and Dermo
• The Department is committed to continued collaboration with all parties to mitigate the evolving impacts of MSX and Dermo.
• Since the detections of MSX and Dermo in Atlantic Canada, the Department’s laboratories have conducted more than 18,000 tests to detect the diseases throughout the Atlantic provinces.
If pressed on what the Department is doing to support MSX research
• My Department announced approximately $1 million in funding for external experts in 2024, to support scientific research toward addressing knowledge gaps in our understanding of MSX. Also, my Department continues to undertake internal research.
• On November 13-14, 2024, my Department co-hosted a Science Summit on MSX with the Province of Prince Edward Island, which gathered national and international experts and partners to discuss what is known about MSX and define priority areas where additional research is needed.
If pressed on what resources are available to harvesters impacted by MSX and Dermo
• My department is dedicating up to $6 million for a one time license buy-back program to support wild oyster harvesters who choose to participate in this program.
Support for reskilling, innovation, product diversification, and business planning is also available, as is employment insurance.