Claims about salmon viruses simply incorrect
Gary Marty, Nanaimo Daily News, August 24, 2012
Re: ‘Government testing of salmon a flawed process’ ( Your Letters, Aug. 21)
As the fish pathologist for the B.C. Ministry of Agriculture, I am disappointed to see Alexandra Morton continue to mislead readers with inaccurate statements about salmon diseases in British Columbia.
She says that the farmed Atlantic salmon virus “infectious salmon anemia virus (ISAV) is one of these farm animal influenzas and it has spread everywhere large numbers of Atlantic salmon are raised in ocean pens.” This statement has two errors.
First, ISAV is not an influenza virus; instead, it is an isavirus. And second, B.C. has millions of Atlantic salmon raised in ocean pens but no confirmed evidence of ISAV. This conclusion is supported by thousands of tests, including all results reported by Alexandra Morton.
Morton said that “I found (ISAV) in B.C.”
This is not correct. It has now been 10 months since Morton first reported positive PCR test results for ISAV in fish that had no evidence of the disease ISA, but her test results have not confirmed either the ISA virus or the ISA disease.
Unconfirmed PCR test results that are not related to disease are usually false positives. False positive test results are not a threat to either wild or farm salmon.
Morton also said that “during the (Cohen) inquiry we learned DFO found 100% of the Cultus Lake sockeye . . . had tested positive for this virus.”
This is not correct. Researcher Molly Kibenge sequenced her PCR product and reported that “The sockeye clones do not resemble any ISAV isolate” and, they “show homology to short sequences of human, mouse, rat and zebrafish clones” (Cohen Commission Exhibit 2140).
These results are called “nonspecific amplification.” It means that the test did not work properly and needs to be redone. Tests that do not work properly are not a threat to wild or farm salmon.
Finally, Morton says that “CFIA will not be testing the millions of farm salmon being raised among the wild salmon” and, “The status of these viruses in salmon farms will be left to the industry to report.” The first statement is misleading; the second is not correct.
DFO’s website “Fish Health Management in the Pacific Region” clearly describes their extensive fish health program that tests for ISAV in fish that die on the farms. CFIA sees these results, and the B.C. Ministry of Agriculture runs these tests for DFO. So far this year, ISAV test results on all 341 farm salmon analysed as part of this program have been negative — no virus.
For early detection of disease, I estimate that testing fish that die on the farms is 400 times more sensitive than random testing of live fish or harvested fish. This means that this year, DFO has tested the equivalent of 136,400 of the supermarket fish tested by Morton.
Alexandra Morton is a great story teller, but much of what she says is just that: a story.
For the best information about salmon diseases and their control, I depend on CFIA, DFO, and the fish farm veterinarians.
Gary Marty B.C. Ministry of Agriculture
Here is the letter Dr. Gary Marty responded to:
Government testing of salmon a flawed process
By Alexandra Morton, The Daily News August 21, 2012
Re: 'CFIA committed to disease control process' (Your Letters, Aug. 16)
While I appreciate the concept that the CFIA is committed to the health of wild salmon, I cannot understand how they can fulfill this role if they refuse to examine Atlantic salmon.
When Dr. Ian Alexander, executive director of the Animal Health Directorate Canadian Food Inspection Agency, says he is working to "determine the status of three diseases in B.C. - infectious haematopoietic necrosis, infectious pancreatic necrosis and infectious salmon anaemia" he fails to say CFIA will not be testing the millions of farm salmon being raised among the wild salmon.
The status of these viruses in salmon farms will be left to the industry to report.
Influenza viruses in farm animals are well-known, that is why wild birds, deer and Bison are strictly keep out of contact with feedlot chickens, pigs, cattle, etc.
Infectious salmon anemia virus is one of these farm animal influenzas and it has spread everywhere large numbers of Atlantic salmon are raised in ocean pens. Viruses are not at all contained in salmon farms, government scientists report 650 billion viral particles can flow out of an infected salmon farm per hour.
This virus is internationally reportable and the Inquiry into the decline of the Fraser sockeye re-opened last winter when my colleagues and I found it in B.C., despite assurances from government and industry that is not here. Dr. Kim Klotins of the CFIA testified that if ISA virus is confirmed in B.C., some countries might refuse to buy B.C. farm salmon.
B.C.'s Minister of Agriculture, Don McRae told the Legislature that following the positive tests for this virus, U.S. and Asian lawmakers were pushing to close their borders to B.C. farm salmon.
Also during the inquiry we learned DFO found 100% of the Cultus Lake sockeye (the most endangered Fraser sockeye stock) had tested positive for this virus and they never revealed this information to the inquiry nor the Stó: l Nation.
The international response to salmon influenza is to kill the infected fish. If the CFIA is going to test wild salmon, they must also test farmed salmon otherwise we could find ourselves in a situation where the wild salmon are being culled to protect the farm salmon. In fact there is a DFO website suggesting this: "Under some circumstances, under the Health of Animals Act, the Canadian Food Inspection Agency may need to treat wild fish populations to control fish pathogens that may have been introduced into Canadian waters."
There is no "treatment," other than culling.
There is something wrong when the virus is easily found in farmed salmon in supermarkets, but there is no government followup to track it to source, nor any testing of the Norwegian industry fish at all, and the only government admission that fish pathogens may have been introduced to B.C. is culling wild salmon.
Alexandra Morton Echo Bay
Link to CFIA Letter: CFIA committed to disease control process
