In response, the\u00a0BC Salmon Farmers Association<\/a>\u00a0emailed Cortes Currents that while these studies reported the presence of viruses, they did not show they were causing disease in farmed or wild salmon.<\/p>\n Today\u2019s program largely consists of interviews with\u00a0Dr Andrew Bateman<\/a>\u00a0from the\u00a0Pacific Salmon Foundation<\/a>\u00a0(PSF)\u2019s\u00a0Strategic Salmon Health Initiative<\/a>\u00a0(SSHI), one of the scientists involved in these studies, and readings from the industry\u2019s response.<\/p>\n <\/p>\n The first of these studies was published last October, the month that Fisheries and Oceans Canada declared the results of its nine assessments.<\/p>\n \u00a0A University of Toronto led study<\/a>, \u201cfound that the probability of detecting pathogen environmental DNA was 2.72 times higher at active versus inactive salmon farm sites.\u201d<\/p>\n This study was conducted at 58 active and inactive farm sites, over a three year period.<\/p>\n In the paper\u2019s abstract it states, \u201cOur findings suggest that salmon farms serve as a potential reservoir for a number of infectious agents; thereby elevating the risk of exposure for wild salmon and other fish species that share the marine environment.\u201d<\/p>\n Lead author Dylan Shea and four of the twelve contributing scientists were from the\u00a0University of Toronto\u2019s Department of Ecology and Environmental Biology<\/a>, but there were also scientists from the\u00a0DFO\u2019s Pacific Biological Station<\/a>\u00a0in Nanaimo, the\u00a0DFO\u2019s Institute of Ocean Sciences<\/a>\u00a0in Sidney, the University of Victoria\u2019s\u00a0School of Environmental Studies<\/a>, UBC\u2019s\u00a0Department of Medicine<\/a>, and the University of Hawaii\u2019s\u00a0Department of Earth Sciences<\/a>.<\/p>\n One of the contributing scientists,\u00a0Dr Andrew Bateman<\/a>\u00a0from the\u00a0Pacific Salmon Foundation<\/a>\u00a0(PSF)\u2019s\u00a0Strategic Salmon Health Initiative<\/a>\u00a0(SSHI), explains, \u201cTechnically: We can\u2019t say whether it is the infectious agents themselves, or whether it is just fragments of the DNA that we are detecting that are elevated around farms, but most people would interpret the findings as being suggestive that active Atlantic salmon farms do elevate the infectious burden for certain infectious agents in the marine environment. It is sort of: where there is smoke, there is fire\u201d<\/p>\n Dr Andrew Bateman (on board a boat) \u2013 photo submitted by Dr Andrew Bateman<\/p><\/div>\n The BC Salmon Farmers Association (BCFA) emailed that viruses are among the most abundant natural biological agents in the world.<\/p>\n They reject any suggestion that salmon farms are responsible for these viruses, adding that farmed salmon are tested for a number of pathogens before being introduced to ocean pens.<\/p>\n \u201cThe recent papers do not explore evidence to show that the detected genetic material or viruses were causing disease either in farmed or wild fish. Further, the presence of genetic material of potential pathogens in the marine environment (as in Shea et al 2020) is not indicative of viable viruses. An important step in studying viruses is to determine whether they are causing disease. These studies did not move beyond detection. Therefore, these papers offer speculative conclusions that these viruses are viable and causing disease,\u201d wrote the industry spokesperson.<\/p>\n Dr Bateman described the studies as part of a body of work looking into infectious agents in farmed and wild salmon.<\/p>\n \u201cIt is very important to know what farmed salmon are infected with and what they may be spreading,\u201d he added.<\/p>\n One of the industry criticisms was that \u201cThe authors also do not include the measure of distance in proximity to farms from which their samples were taken.\u201d<\/p>\n To which Bateman responded, \u201cWe did, indeed, sample water from nearby active farms and away from active farms. The sites away from active farms\u00a0 \u2026 were a mix of fallow farms (farms where there is still a farm structure but no fish) combined with decommissioned sites (sites where there is no evidence, to the naked eye, of there having been a farm).\u201d<\/p>\n Figure 1 \u2013 Locations of the salmon farms and fish hatcheries used in Bateman et al,\u00a0Descriptive multi\u2010agent epidemiology via molecular screening on Atlantic salmon farms in the northeast Pacific Ocean<\/p><\/div><\/figure>\n Last Month, Dr Bateman was the lead author of the paper\u00a0Descriptive multi\u2010agent epidemiology via molecular screening on Atlantic salmon farms in the northeast Pacific Ocean<\/a>, published in Scientific Reports.<\/p>\n He and his colleagues from the DFO\u2019s\u00a0Molecular Genetics Lab<\/a>\u00a0at Pacific Biological Station in Nanaimo, the Pacific Salmon Foundation in Vancouver, and UBC\u2019s Department of Medicine, studied 58 infectious agents found in farmed salmon.<\/p>\n Cutthroat trout virus (CTV-2) and the Atlantic Salmon Calicivirus (ASCV)<\/p>\n Bateman also cited a\u00a0recent study, whose lead author was Dr Gideon Mordecai from UBC, that dealt with viruses that had not previously been detected in BC<\/a>. Cutthroat trout virus (CTV-2) and the Atlantic Salmon Calicivirus (ASCV) were among them.<\/p>\n The BC Salmon farmers Association pointed out there had been no evidence on BC salmon farms, or in the wild, that either of these viruses causes disease.<\/p>\n Bateman concurred, \u201cWe don\u2019t know what these viruses do, or if they cause disease in wild or farmed salmon. That is one of the outstanding questions.\u201d<\/p>\n He added, \u201cThe concern is not that we have hard and fast evidence of a disease, it is that there is a virus and it is infecting fish whether they are farmed or wild. It may cause a problem and it may not.\u201d<\/p>\n One of the viruses they studied was\u00a0Piscine orthoreovirus (PRV)<\/a>, one of the nine pathogens the\u00a0DFO recently declared to be of minimal risk<\/a>. The strain found in BC (PRV-1) appears to have originated among Atlantic Salmon and arrived when fish farms were introduced during the 1980s.<\/p>\n \u201cThere is some debate about the exact timing, but there is pretty much agreement on the fact that PRV-1 arrived in BC from the Atlantic,\u201d said Batemen.<\/p>\n The BC Salmon Farmers Association disagree and, in their email claim that\u00a0PRV\u00a0is\u00a0endemic\u00a0in BC.<\/p>\n \u201cWhen and how PRV came to be present in BC are not clear. There have been confirmed detections at the molecular level of\u00a0PRV-1 in samples dating back to the mid-1980s in Pacific salmon, in 1993 in Washington state Coho salmon and recently in a historical review of data, a Steelhead Trout sample taken in BC in 1977,\u201d their spokesperson wrote.<\/p>\n The BC Salmon Farmer\u2019s Association\u00a0cited a recent study<\/a>, co-written by eight scientists, suggesting that while the strains of PVR-1 in Pacific and Atlantic Canada are related, they are genetically distinct. They share a common ancestor with strains from\u00a0 Iceland and Norway. The author does not know when this strain of PRV-1 reached BC waters.<\/p>\n \u201cIt could have arrived when more than 8 million wild Atlantic salmon were introduced to BC rivers and streams a century ago between 1905 and 1935, under a federal government program,\u201d they wrote.<\/p>\n Bateman responded, \u201cThese kind of studies always have a degree of uncertainty, but we in the Strategic Salmon Health Initiative are of the opinion that the more recent date is more accurate because it combines more of the available data more holistically.\u201d<\/p>\n He added, \u201cAll recent studies of which I am aware are in agreement that the PRV we have in BC appears to have come from the Atlantic Ocean.\u201d<\/p>\n In their email, the BC Salmon Farmers Association cites a study that \u201cfailed to induce disease or mortality when exposing Pacific (Sockeye and Chinook) and Atlantic Salmon to the BC strain of PRV in a lab-based study.\u201d They concluded,\u00a0 \u201cThis suggests PRV in BC has a low ability to cause disease for these species.\u201d<\/p>\n So far, Bateman and his colleagues are also finding that Sockeye is less susceptible to PRV-1 than other salmon.<\/p>\n He added, \u201cOur preliminary analysis indicates that PRV-1 infection in wild fish may be linked with poor ocean survival for wild Coho and wild Chinook salmon. For Chinook in particular, the patterns that we see in terms of spatial infection profile, indicate the levels of infection are higher around salmon farms.\u201d<\/p>\n One of the other examples Bateman gave was Tenacibaculum maritimum, a bacterium that affects fish around the world.<\/p>\n \u201cWe see quite high levels of infection on Atlantic Salmon farms in BC. And we are also beginning to see preliminary evidence that for Chinook and Sockeye Salmon in particular, infection in the wild may be tied to poor survival. Unfortunately, Sockeye salmon, as they are heading north out of the Fraser River, seem to pick up Tenacibaculum around salmon farms in the Discovery Islands,\u201d he said.<\/p>\n This prompted the BC Salmon Farmers Association to cite two studies suggesting that \u201cthe disease noted in Atlantic salmon caused by\u00a0T. maritimum\u00a0<\/em>has never been detected in any species of wild Pacific salmon, even though the wild fish may carry the bacterium.\u201d<\/p>\n They pointed out that in addition to being found on salmon, this bacterium has also been identified and isolated from sediment, the surface of tanks, and water cultures.<\/p>\n To which Bateman replied, \u201cSpecifically, in Atlantic Salmon farms in British Columbia, Tenacibaculum maritimum causes a disease called mouth rot. That disease, to my knowledge, has not been observed anywhere else.\u201d<\/p>\n Figure 3 \u2013\u00a0depicting the Agent intensity of four viruses, three of which are discussed in this article \u2013 from\u00a0Bateman et al, Descriptive multi\u2010agent epidemiology via molecular screening on Atlantic salmon farms in the northeast Pacific Ocean<\/p><\/div><\/figure>\n Salmon farms are not the only sources of infectious agents and infectious agents are not the only threat to wild salmon.<\/p>\n \u201cOcean conditions generally: things like food availability, or competition with other species are directly linked to salmon survival. Ocean temperatures in particular, are one thing that predicts the performance of salmon stocks. With warmer temperatures tending to be worse for salmon and all else being equal, this tends to be cause for concern as we move forward and temperatures are warming,\u201d said Bateman<\/p>\n He added, \u201cIn any science, there is always room for uncertainty. That is part of the nature of the beast and how we deal with that is part of the process.\u201d<\/p>\n By Roy L Hales Three recent academic papers suggest that salmon farms may pose more than a minimal risk to wild salmon migrating through the\u00a0Discovery Islands. In response, the\u00a0BC Salmon Farmers Association\u00a0emailed Cortes Currents that while these studies reported the presence of viruses, they did not show they were causing disease in farmed or wild…<\/p>\n","protected":false},"author":34,"featured_media":49409,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[217,222],"tags":[7670,7671,5280,7155],"radio":[252],"origine":[280,266,231],"acf":[],"_links":{"self":[{"href":"https:\/\/canada-info.ca\/en\/wp-json\/wp\/v2\/posts\/49407"}],"collection":[{"href":"https:\/\/canada-info.ca\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/canada-info.ca\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/canada-info.ca\/en\/wp-json\/wp\/v2\/users\/34"}],"replies":[{"embeddable":true,"href":"https:\/\/canada-info.ca\/en\/wp-json\/wp\/v2\/comments?post=49407"}],"version-history":[{"count":0,"href":"https:\/\/canada-info.ca\/en\/wp-json\/wp\/v2\/posts\/49407\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/canada-info.ca\/en\/wp-json\/wp\/v2\/media\/49409"}],"wp:attachment":[{"href":"https:\/\/canada-info.ca\/en\/wp-json\/wp\/v2\/media?parent=49407"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/canada-info.ca\/en\/wp-json\/wp\/v2\/categories?post=49407"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/canada-info.ca\/en\/wp-json\/wp\/v2\/tags?post=49407"},{"taxonomy":"radio","embeddable":true,"href":"https:\/\/canada-info.ca\/en\/wp-json\/wp\/v2\/radio?post=49407"},{"taxonomy":"origine","embeddable":true,"href":"https:\/\/canada-info.ca\/en\/wp-json\/wp\/v2\/origine?post=49407"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}Reservoir for infectious agents<\/h2>\n
![\"Dr](\"https:\/\/cortescurrents.ca\/wp-content\/uploads\/2021\/03\/boat-headshot-682x600.jpg\")
Fish farm response<\/h2>\n<\/div>\n
Looking at infectious agents<\/h2>\n
Proximity to farms<\/h2>\n
![\"Locations](\"https:\/\/cortescurrents.ca\/wp-content\/uploads\/2021\/03\/41598_2020_78978_Fig1_HTML-800x519.png\")
Studying 58 infectious agents<\/h2>\n
Where did BC\u2019s PRV virus originate?<\/h2>\n
Is PRV a serious threat?<\/h2>\n
Tenacibaculum maritimum<\/h2>\n
![\"](\"https:\/\/cortescurrents.ca\/wp-content\/uploads\/2021\/03\/41598_2020_78978_Fig3_HTML-596x600.png\")
Not the only threat to salmon survival<\/h2>\n
Links of interest:<\/h2>\n
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