PRV virus

Salmon farmers embrace new PRV testing rules

New PRV testing policy will only apply to aquaculture industry for now as government begins consultation on the transfer of live fish into the ocean environment.

By Fabian Dawson

Fish farm hatcheries in British Columbia will have to test for two foreign strains of the piscine reovirus (PRV) under a new policy being implemented by Canada’s Department of Fisheries and Oceans (DFO).

But similar hatcheries under DFO’s Salmon Enhancement Program (“SEP”), which release millions of salmon smolts into the marine environment, do not have to do the new PRV tests, at least for now.

A DFO spokesperson told SeaWestNews that the new PRV testing rules announced this week will only apply to “B.C. salmon aquaculture industry hatcheries.”

“The Department will collect samples for screening and the costs to analyse the samples will be covered by the Department,” said the spokesperson in an emailed response to SeaWestNews.

“We are exploring options on where testing will be done. There are accredited labs in B.C. that can do this type of molecular analysis.” 

The spokesperson said DFO is currently consulting with experts, stakeholders and the public on an interim ‘Framework on the Transfer of Live Fish’ that when finalised “would apply to all fish movements.”

At any given time, there are about 60 to 70 ocean-based fish farms operating in B.C. The industry contributes over $1.5 billion annually into B.C.’s economy and occupies 0.05% of the entire B.C. coast.

There are also 132 SEP licences to grow Pacific salmon for release of which 18 are DFO operated hatcheries, 99 are community hatcheries and 15 are classroom facilities.

The new policy follows a federal court ruling earlier this year that ordered DFO to amend its rules on testing salmon for PRV before they are transferred to ocean pens.

Anti-fish farm activist Alexandra Morton and the Namgis First Nation claimed in court that salmon smolts being introduced to ocean fish farms needed to be screened for the PRV virus because it is linked to disease in salmon.

Despite overwhelming scientific evidence to the contrary, they had argued that farmed fish with the PRV virus would infect wild salmon passing by the farms and further threaten declining salmon populations.

And they said DFO failed to properly consult with the Namgis First Nation when developing the transfer policy, thereby infringing on their traditional territorial rights.

The court dismissed their science but agreed that DFO needed to consult with the Namgis over the policy and had given DFO four months to review its rules around transferring baby salmon to the ocean environment.

The deadline expired June 4.

PRV has long been present in wild salmon in Pacific Northwest waters and the common scientific consensus is that PRV does not have the same harmful effect on Atlantic salmon farmed in Pacific waters at it does in Norway.

All experimental exposures of the BC strain of PRV to Pacific and Atlantic salmon in B.C. have failed to induce disease or mortality. This suggests PRV in BC has a low ability to cause disease the DFO has concluded.

Fisheries officials also said in February that data shows PRV poses minimal risks to wild sockeye salmon stocks in B.C.’s Fraser River.

Shawn Hall, a spokesman for the B.C. Salmon Farmers Association said his members are reassured that government is following through on its commitment to make decisions in aquaculture regulation based on sound scientific principles.

“The science tells us there are different strains of PRV around the world, and that the one in BC is naturally here and benign. Requiring farmers to test for foreign strains of this virus is a responsible approach,” he said.

“Our farmers already take the precaution of testing for a number of known pathogens that can impact fish health before smolts move from hatcheries to the saltwater environment. Testing for this additional virus will now be part of an already rigorous process.”

In addition to the new PRV tests, DFO also announced that it will be requiring enhanced testing and reporting of any instances of heart and skeletal muscle inflammation (HSMI) and jaundice syndrome.

“The Department will be investing additional resources to undertake increased audits at farm sites to ensure proper monitoring and enhanced monitoring of farmed fish health,” DFO said in a statement.

Three new Technical Working Groups, focused on area based approaches to aquaculture management, aquaculture production technologies (including closed containment) and fish health will guide the formation of Canada’s first Aquaculture Act, said Jonathan Wilkinson Minister of Fisheries and Oceans and the Canadian Coast Guard.

The government also released two draft risk management documents aimed at enhancing the Department’s science-based decision-making processes on aquaculture:

  1. An interim Framework for Aquaculture Risk Management (FARM) to provide a consistent, predictable process for aquaculture risk management that ensures wild fish and their habitats are protected. This risk-management framework also explains how a precautionary approach for aquaculture decision-making is to be implemented; and
  2. An interim Framework on the Transfer of Live Fish that provides guidance on the authorization of the movement of fish in marine environments and what, if any, additional mitigation measures are needed to protect wild stocks. The interim framework sets out a process for assessing the impact of transfers on wild fish and determining if testing for pathogens is warranted.

The government will seek public feedback on these two documents over a 60-day period, starting on June 4, which includes consultation with the Namgis First Nation.

“Our government is committed to the protection and conservation of wild Pacific salmon,” said Wilkinson.

“The new safeguards announced today will protect wild salmon and enhance environmental sustainability of aquaculture in British Columbia,” he said.

(Seymour Hatchery image courtesy of DFO)

What is PRV?

Piscine reovirus is a virus that can infect Atlantic and Pacific salmonids. Reoviruses get their name because many are respiratory and enteric orphans. They are called “orphans” because many are viruses without an associated disease.

Is PRV found in British Columbia?

Yes. Research published in 2014 suggests PRV has long been present in wild salmon in Pacific Northwest waters.

What impact does PRV have on salmon?

PRV has been detected in healthy fish in healthy populations, showing that its presence does not mean disease occurs.

But isn’t a virus a disease?

No. Not all germ’s in our environment cause disease. There are millions of viruses in every drop of seawater. Viruses are carried by all living things and most never cause disease. Other reoviruses have been found for decades in wild fish and never associated with disease. In British Columbia, there is no link between the presence of PRV and any disease.

Do salmon farmers test for PRV?

Yes. BC salmon farmers provided samples for the 2014 scientific study that documents PRV in BC and Alaska salmon without associated disease. BC salmon farmers are providing samples for other scientific studies that are underway. This is being done even though Fisheries and Oceans Canada (DFO), and the Canadian Food Inspection Agency (CFIA), do not have PRV on the list of reportable diseases/pathogens.

What about the suggested link between PRV and heart and skeletal muscle inflammation (HSMI)?

That link refers only to Norwegian strains of PRV in farmed Atlantic salmon. HSMI is common in Norway, but HSMI has never been identified in any wild fish in the Pacific Northwest. Viruses with the same name often occur as different types in different parts of the world. Some types might cause disease whereas others do not. PRV is a good example.

Is there any human health risk associated with PRV?

No. Viruses found in salmon (including PRV) are not a risk to human health.


A new approach for aquaculture in B.C.

New studies reaffirm PRV is not a salmon killer

Virus poses minimal risk to Fraser River sockeye salmon

(Seymour Hatchery image courtesy of DFO)