Woman sitting in a zodiac, examining contents of a small net net

70% of the fish farms sampled had PRV-1, study finds

A new study published by the Canadian Journal of Fisheries and Aquatic Sciences, states that 70% of the samples taken from 56 fish farms had PRV-1.

One of the co-authors is independent biologist Alexandra Morton, who explained, “The study was my concept and I funded a lot of the analysis and did a lot of the sampling myself. It was truly collaborative with Clayoquot Action sampling the Farms in Clayoquot Sound. An extraordinary man, Dr. Neil Fraser from Powell River got in his speed boat and went to the central coast. The Wild Fish Conservancy down in Washington State, sampled farms there. So it was  a sustained effort by a lot of people, and then Dr. Gideon Mordecai did the analysis of the relationship between the different strains that we picked up.”

Looking up Calm Channel towards Raza Island, the Mainland and Stuart Island, from a boat off the northern tip of Cortes Island – Photo by Roy L Hales

Cortes Currents reached out to Dr Mordecai, lead author of ‘Detection and phylogenetic assessment of PRV-1 via sampling of biological materials released from salmon farms in British Columbia‘ and a Research Associate with the Institute for the Oceans and Fisheries at UBC. He is currently on vacation but emailed that he will be ‘happy to chat’ after he returns. 

Brian Kingzett, Director of Science and Policy for the BC Salmon Farmers Association (BCSFA) emailed a few immediate responses. I will read some of these out after discussing findings from the new paper by Mordecai et al. Kingzett has also been invited to submit an Op-Ed to Cortes Currents.

Related: PRV spreads from salmon farms to wild Chinook, study says

Some of the Discovery Island sites where Morton and her colleagues took samples are also within our broadcast area. So I asked Morton for any details she had about Raza Island, which is off the Northern tip of Cortes Island, and the Okisollo Channel, between Quadra and Sonora Islands.  

Alexandra Morton: “A lot of this work was done while I was on the Sea Shepherd vessel, ‘Martin Sheen,’ because I now had a platform that moved up the coast and we could stop at any farm and didn’t have to go home for the night or due to weather.”

“We were able to go farm to farm to farm. When we arrived in Okisollo Channel at the Venture Point Farm owned by Cermaq, there were so many fish floating on the surface that I said to the captain, let’s just stay here for a while. That’s where the collection began. It was very concerning because this was in the summer, when the Sockeye were returning through that channel and around that channel.”

“I kept calling DFO’s Aquaculture Management Division, which is based right in Campbell River, and various other people. Chief George Quocksister Jr also made calls. Nobody would come out and sample around that farm. Clearly, the fish were in distress. They were dying. They were lying on the surface.”

Alexandra Morton: “When you look at those four red dots in Discovery Islands, in Okisollo, what you see is that we got PRV from all those farms, which really is not surprising. This is a highly contagious virus, travels well in the water. It’s very hard to kill, and yes, it infected all those farms as well as Raza.”

“The good news is that all those farms are gone. The only farm that is left in the Discovery Islands is the red dot, sort of under the letter J way up in Johnson Straits in the western edge of the study area. Shaw Point is not in the DFO map of Discovery Islands, so it escaped the decommissioning that the other farms are going through.”

Related: The BC Salmon Farmers Association’s new ‘independent’ sea lice report

“This risk to all the salmon in this area has been removed. I can see the sea lice data, because I’ve been down there in 2019, 2020, 2021 and 2022, counting sea lice on the juvenile salmon migrating through there. I can see the sea lice have vanished and I can’t see the virus. I’m hoping that with the removal of the farms, the exposure to this virus has been greatly reduced for all these populations in that area.” 

Summary of Findings

Morton:  “First of all, we had to figure out a way to sample viruses from salmon farms in the face of the obstruction that the industry puts around this kind of research. They don’t allow you to access their fish. I have done research in the past where I have accessed farm salmon from supermarkets in British Columbia, but you never know exactly what farm they’re coming from. So I figured out that if you take a small aquarium net, which is a very fine mesh, and you circle the farms slowly, you can find the bits of rotting flesh and scales and feces that are coming out of these farms. Literally tons are coming out, and so it’s not that hard to pick some of it up.” 

“We did that from Southern Puget Sound, to the central coast of British Columbia, including both sides of Vancouver Island. It was a highly collaborative effort with a number of groups and then we sent the viruses for analysis.”

“We screened for the Norwegian virus Piscine Orthoreovirus or PRV, and there were four big findings.” 

“One, most of the farms where we actually got samples are shedding the virus.” 

“This is a concern because as I was readying my net to dip these little pieces of flesh out of the water, there were many circumstances where juvenile, wild salmon or herring went after the same piece that I was going after and got it. This suggests that the virus is being carried beyond the tenure of the farm.”

“I don’t know what happens when a herring, for example, eats an infected piece of farm salmon. Does it actually begin to replicate or hurt the fish, or does it just become a carrier? We don’t know this, but we do know that it’s being eaten and that these fish are free to move beyond the pens.”

A man and a woman in a boat, examining a fish
Bonny Glambeck and Dan Lewis of Clayoquot Action collect fish farm samples. Photo by Jérémy Mathieu / Clayoquot Action

“The genetic analysis of all the virus samples suggest that this virus is originating in the hatcheries of the salmon farming companies. The reason is farm sites that were widely separated but owned by the same company had viral sequences that were very similar, and this suggests it came from the hatchery, not from the wild environment.” 

“Secondly, we found this virus is mutating. It’s from Norway, but it’s mutating in British Columbia, which is no surprise. Salmon farms are feed lots and feed lots give viruses an extraordinary opportunity to mutate because the hosts are so densely packed together. The virus jumps fish to fish, but also there’s no predators in the farms to remove the sickest, most contagious fish, the ones that are shedding the virus. The virus is shed from the moment of infection and replication in the fish to the actual moment that it dies, which can take a long time as the fish just waste away.”

“There was one more finding that’s disturbing, but we don’t know what it means. The PRV in the Chinook Farms in Tla-o-qui-aht territory off of Tofino matched the virus in Chinook hatcheries in the Columbia.  This raises a number of issues. One, it suggests the virus is mutating, to adapt to Chinook salmon.”

“We know from research in these farms into Tla-o-qui-aht territory, they’re owned by Creative Salmon. We know that the virus is getting into the red blood cells of Chinook Salmon, and as it replicates, it fills the cells and causes them to explode. Overwhelming the fish with hemoglobin and then causing jaundice so the fish actually turned yellow.”

“This is research that DFO scientist Dr. Kristi Miller has been working on for a long time, but through industry and DFO that research has been blocked from publication. So it’s a very sensitive issue, to find the same virus in a Chinook hatchery in the Columbia.This was not just our finding, we just verified research that has been done by others.”

“Either there’s communication between this hatchery in the Columbia River and the creative salmon farms: maybe they’re getting eggs from there; maybe genetic materials going back to the hatchery. We don’t really know. We know this does go on up in the Yukon. The Yukon Chinook were the first Chinook used to stock the Creative Salmon farms, and we know from news articles and from internal DFO documents that sperm from the Creative Salmon Chinook was sent back to the Yukon. Coincidentally, the Yukon Chinook are collapsing and nobody knows why. I’ve been trying to contact First Nations there to suggest they screen for PRV, but so far it’s a just too volatile subject.  The other potential is that Chinook migrating from the Columbia are somehow picking up this virus selectively. The Tla-o-qui-aht Farms have one strain, but the Ahousaht Atlantic salmon farms have a slightly different strain.  I don’t know why the Columbia are picking up the Tla-o-qui-aht strain versus the Ahousaht, but in any case, it’s a Norwegian virus and it’s up to no good.”  

Related: Testimonies before the Standing Committee on Fisheries and Oceans

Emailed Comments from BC Salmon Farmers Association

A spokesperson for the BC Salmon Farmers Association emailed Cortes Currents, “We have not had time to have fish health professionals review the paper.” 

She never-the-less provided some immediate responses from Brian Kingzett, their Director of Science and Policy.

“The authors sampled biological material around salmon farms for an endemic virus we would expect to find everywhere in the ocean and then fail to mention that they had no control sampling locations to compare.”

It has been 18 months since Drs Mordecai, Kristi Miller from DFO’s Pacific Biological Station in Nanaimo, and a dozen other scientists from UBC, the Pacific Biological Station and Pacific Salmon Foundation  published a study suggesting that salmon farms could be transmitting PRV-1 to wild salmon populatins

At that time Mordecai told Cortes Currents, “Our findings show that salmon farms are, indeed, a source of infection for wild fish. Viruses leave a genetic fingerprint. The genetic fingerprint shows that the same viruses that are on the farms are in the wild fish. All the evidence suggests that the virus is being transmitted from the farm to wild fish. I haven’t seen any evidence that says that’s not happening.”

Kingzett claims the stain of PRV found in British Columbia has not been shown “to have a negative effects on wild or farmed salmon” and the authors of the present report are making ‘unfounded conclusions.’

“The work on whether the virus is mutating is new and poorly supported — but the authors jump to giant conclusions that this is the result of aquaculture,” he wrote. “Additionally, what the paper concludes and the claims that Morton is making on her social media about the paper do not line up.” 

A quick comparison of the main points from the paper and what Morton said during our interview suggests the alleged difference may be one of opinion rather than fact.  

For example, the paper states “We collected biological samples adjacent to 56 marine net pens from five different companies, and two farm salmon processing plants (n = 230), 70% of samples were positive for Piscine orthoreovirus-1 (PRV-1).”

Morton told Cortes Currents,”  We collected biological samples adjacent to 56 marine net pens from five different companies, So that’s Cermaq, MOWI, Grieg, Creative Salmon, and Cook Aquaculture in Washington State.  70% of these samples were positive for PRV-1.” 

Putting specimen collected beside a fish farm into a vial for genetic analysis- Photo courtesy Alexandra Morton’s Facebook Page

The paper also states, “We differentiated the sample types by buoyancy’; ‘unidentified biological material,’ ‘feces-lik,’ and ‘scales’ were suspended below the surface, while biological material floating on the surface was categorized as ‘lipid-like.’ Samples were typically <5 mm in any dimension, and hence material from each site was pooled within vials to provide a sufficient amount (approximately 0.1 g) of material for testing.”

Morton’s explanation is both more colourful and illuminating: 

“The vast majority of these farms are shedding the virus into the marine environment, but they’re doing it in these tasty packages of flesh, but also scales and feces. This is attracting wild fish and observations that I made during these collections was that the wild fish are darting after these bits of flesh. So are seagulls. So I don’t know what it’s doing in the seagull’s body. Seagulls have warm blood, so perhaps nothing, but is it sticking to the feathers as they move off and land? It means that the virus is finding ways to spread beyond what the currents are already doing.”

The following text also agrees with Morton: 

“Recent studies with access to farm salmon found that certain infectious agents (including PRV-1) are detected in freshwater hatcheries, and these are likely translocated to the marine environment via transfer of fish from infected hatcheries into marine farms (Bateman et al. 2021).” 

But the study goes on to state: 

“There is minimal sequence data available of PRV-1 from hatcheries, but genomic surveillance of PRV in BC salmon farms could help to determine the source of infection, as similar lineages of PRV would be expected in farms stocked from the same hatcheries. The alternative hypothesis is that PRV is transmitted from the marine environment (either via wild fish, or other nearby farms) to net pens, where the infection then spreads within the farm. This issue remains uncertain because there is little publicly available data on the infection rate in hatcheries.”

There is more room for alternate explanations in that statement. 

I look forward to interviewing lead author Dr Gideon Mordecai when he returns. 

 Related: Articles about Climate Change threatening the survival of Wild Salmon

Need to focus on Pathogens

  Morton: “It’s extraordinary to me that in the efforts to restore wild salmon, that there has not been more focus on pathogens. It just seems a natural thing to investigate, particularly when high water temperature is rising. It is a stressor, so it makes fish that are infected even weaker and more likely to succumb to the virus.”

“Now, I have to say that prior to salmon farming on this coast, people were quite open about pathogens.  There was a Dr. Wolf that wrote about, for example, the spread of the IHN virus from enhancement hatcheries into the wild. It was openly talked about because people wanted to deal with it.

They wanted to stop this.” 

“Since the salmon farming industry has come on scene, literally,  salmon health in terms of pathogens has become a state secret. When I first started sampling for viruses, enhancement hatcheries related to DFO were instructed not to provide samples to me. And this is strange because I was testing for viruses.”

“I would provide them with the results. This is expensive work that I was willing to do for free for them,  so that they could move forward and respond to try to remove these pathogens from their facilities. But you can’t pick up a salmon anymore and put it in a hatchery and be confident that you’re not bringing PRV or the Tenacibaculum bacteria, or other pathogens that are being amplified from these farms.”

“To put it bluntly, the waters of British Columbia have been somewhat weaponized against wild salmon by this super loading of pathogens that they just have not evolved  to live with, to survive and. Salmon farming industry is vehemently against this sort of concept, but it doesn’t matter what they say.”

“We know that both native pathogens and foreign pathogens are in these farms and that these populations of Atlantic salmon do not exist on this coast. Number one, we don’t have Atlantics, but number two, salmon move and they are honed by predators every day of their life. From the moment the egg leaves the mother’s body, there’s a predator for any salmon that is weak and that just keeps the population healthy, and so the salmon farms don’t do that.”

“Some people have asked me about this mutation that we’re seeing arise in the PRV in British Columbia, and whether it is a more virulent strain, we don’t know that.”

“We don’t have the kind of research going on that, of course, was applied to COVID that tells you exactly what portion of the virus mutated and is it attached to the cells. What is that mutation doing? We don’t know that.  What we do know, from an enormous body of research, is that when you allow viruses to mutate in feed lot environments, you are selecting for higher virulence.”

“The reason is simple. In the farms, there is no long term potential prospects for any pathogen. All the fish are going to die in a certain day and that is picked by the company, not by the health of the fish.  The fish isn’t going to migrate, it isn’t going up a river, it isn’t going to spawn. It’s just going to grow to a certain size and it’s dead.”

“The whole ‘live lightly on your host’ strategy that wild pathogens use, doesn’t work in a salmon farm.  There’s so many other pathogens competing for that host that the better strategy is just come out hard, replicate as fast as you can. Which means higher virulence and try to spread in the short window of opportunity that they have on these fish.”

“So of course it’s concerning that the virus is mutating in British Columbia, which it has already done in Norway. We have an early model of PRV, a less virulent strain. It is causing disease, which DFO and the companies want to say it’s not, but the evidence is too great. It is causing heart damage in fish.”

“We are going to see virulence happen here because it’s so careless what’s going on in these farms.” 

Related: ‘Writing on the wall’ for West Coast fish farms, conservationists say

Morton: “There’s just this remarkable decision that has happened. Washington State has closed all their salmon farms, and those fish have to be out by the middle of December. And the First Nations in shíshálh (Sechelt) on the same day, interestingly, did the same thing.”  

“The Discovery Islands is now clear except for the one farm. Most of the farms are out of the Broughten Archipelago due to the enormous efforts of most of the First Nations in the Broughten Archipelago. That means salmon from the Fraser River, from Washington State and from east Vancouver Island rivers are migrating without exposure to salmon farm pathogens until they get to Port Hardy. Then there’s a bunch of farms, and in the central coast there’s another bunch of farms. 

The same thing is not happening on the west coast of Vancouver Island. All of the Nations there that have salmon farms, have had signed agreements with these companies and they’re going to allow the industry to continue.”

Morton suggested that a grand, but sad experiment appears to be unfolding.

“It’s a grand experiment. It’s sad that it has to be an experiment like this, but next summer will be the first generation of Fraser Sockeye that did not go past salmon farms in the Discovery Islands. They will unfortunately off Port Hardy, but they’ll be bigger then and it’s bigger water, so maybe it was less impact.”

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