Terms of Reference

Residual Infectious Pancreatic Necrosis (IPN) Transmission Risk due to Arctic Char Transfers into British Columbia

Science Response Process – Pacific Region

April 2017
Nanaimo, British Columbia

Chairperson: Mark Higgins

Context

Infectious pancreatic necrosis is a disease affecting some freshwater and saltwater finfish. It is caused by the infectious pancreatic necrosis virus (IPNV), which belongs to the family Birnaviridae. IPNV can be spread by moving infected live or dead finfish, contaminated equipment, or contaminated water. Infectious pancreatic necrosis can cause death in fry, fingerlings, and smolts; including smolts transferred to seawater.  There are no treatment options currently available in Canada for infectious pancreatic necrosis. A number of species of fish are susceptible to, or can carry IPNV including but not exclusive to:

• Cutthroat Trout (Oncorhynchus clarkii)
• Chum Salmon (Oncorhynchus keta)
• Rainbow Trout (Oncorhynchus mykiss)
• Atlantic Salmon (Salmo salar)

Because of the seriousness of the disease, it is a legal requirement to report known or suspected IPNV infections to the Canadian Food Inspection Agency (CFIA). Infectious pancreatic necrosis is considered endemic in New Brunswick and Nova Scotia, and is found in many regions of Canada; however, British Columbia is considered free from this disease.

Arctic Char (Salvelinus alpinus) among other aquatic species can be a carrier of IPNV long after infection, often without showing symptoms of disease.  Detection of the virus in fish that are not showing signs of the disease requires extreme test sensitivity; conventional diagnostic methods are not sensitive enough to detect infection. While Arctic Char are not indigenous to British Columbia, they are commercially cultured in the province on a small scale with most of the stock to date having been obtained from certified disease free sites in the Yukon   A recent request to transfer Arctic Char eggs from a certified disease free facility in New Brunswick, an IPN-positive area, to British Columbia, highlighted the need to review the risks of potentially introducing IPNV into wild and established cultured fish populations in BC. At the time of the request for science advice, the facility in New Brunswick (NB) held a valid Fisheries and Oceans Canada (DFO) Fish Health Protection Regulations fish health certificate (FHC); however there was uncertainty regarding whether the sensitivity of testing associated with this certification was sufficient to ensure an infection free status.  Consequently, DFO Aquaculture Management Branch is seeking advice from Science Branch to assess the risk associated with the introduction of Arctic Char to BC.

The assessment and advice arising from this Canadian Science Advisory Secretariat (CSAS) Science Response (SR), will be used to evaluate risks to wild and farmed BC fish as part of the review process for both aquaculture licence applications and Introductions and Transfers licence applications, as well as to inform decisions related to Arctic Char aquaculture conditions of licence.

Objectives

The specific objectives of this Science Response are to:

1. Document evidence of impacts in other regions where IPN has been introduced.
2. Document the likelihood of Arctic Char being infected with IPNV, and describe potential impact from an import if the Arctic Char were infected to BC wild and farmed fin fish.
3. Identify and describe variable infection risks associated with  importing different life stages to the introduction IPNV infection to BC. (e.g. eggs, milt, fry, juvenile, adult, brood stock etc.).
4. Determine the effectiveness of current testing and management practices in facilities within IPNV affected areas in assessing a true infective status.
5. Recommend management measures to mitigate the potential risks associated with transferring Arctic Char from facilities in IPNV positive areas.
6. Identify any knowledge gaps or uncertainties associated with the advice.

Expected Publication

• Science Response

Expected Participation

• DFO Science, Aquaculture Management Division
• Canadian Food Inspection Agency
• North West Indian Fisheries Commission, Washington State
• Province of British Columbia