N.S. fish farm rejected: risk to wild salmon.

[Birdsnest]

I've probably eaten IHN and likely some of my friends who are opposed to salmon farms have eaten IHN. None of us seamed to mind. Of course we know that it is a naturally occurring virus here on the west coast so what else can u say. Chances are if you have eaten any amount of sockeye you have eaten IHN. Its ok if you are not a biologist AP. Neither am I but to a salmon farmer this is very basic knowledge. Of course if you chose to gobble up the fear mongering have at'er. Your call, but If this is a concern to you its time for you to stop eating wild/hatchery salmon because they all or most carry viruses.

 

[ClayoquotKid]

Well, I am glad that at least we now know who we are talking to! It obviously does make a difference. I think it's great to be able to ask questions directly to Mainstream's Sustainability Officer...who better to ask really?!

So, last summer, when the Millar Channel Farm was emptied and the fish were turned into pet food:

Did Mainstream receive compensation for being 'forced' to take them to market? Or is that just for when you are forced to compost your diseased product?

http://www.hashilthsa.com/news/2012-08-10/latest-ihn-outbreak-forces-cull-millar-channel-fish-farm

I find it so interesting that 400 tonnes of fish could be diseased to the point of them having to be destroyed and that that farm site would no negative effect on passing mature and juvenile salmon passing by it. That's amazing.

Quite a sick joke that those diseased fish were then fed to 'man's best friend'; us humans are so nice.

When a virus like IHNv is found to be present on a farm, the immediate reaction is to remove those fish from the water.

Not all of the fish were positive for the virus, and only a small percentage of the population actually had the disease - the fact that it was confirmed to be present and had caused ANY mortality was enough to cause the company to cull the entire site.

This action not only protects other farms in the area from the potential spread of the virus, but serves to reduce the risk of it being transferred back to the wild from which it came.

IHN is endemic to BC and has been thoroughly studied for years in wild populations, particularly Sockeye.

In this instance the fish were rendered into usable products through a process which cooks everything down in order to separate elements and destroy any biological or viral components which may be present.

This was the most effective and responsible action available, and the fact that a safe and beneficial protein source was obtained isn't something I see as a bad thing.

I'm not sure what the financial situation is regarding compensation, but CFIA has a process in place which deals with the culling of stocks - from bees to chinchillas: http://laws-lois.justice.gc.ca/eng/regulations/SOR-2000-233/page-3.html#h-6

I'm not surprised someone eventually "outed" me here, I'll admit I didn't come on here with full disclosure, but then again I also used a handle I've used elsewhere and made no attempt to deceive or hide from anyone willing to do a little digging.

The fact that you think, "It obviously does make a difference." makes me wonder if you are actually willing to consider the information I bring forward, or if you will simply disregard it because of the nature of the source?

I am still standing behind my view that salmon farms have not been shown to harm wild stocks in any measurable way in their multiple decades of operation on the coast; and everything I have seen in my decade or so of employment has shown me that farms in operation today are acting in a way which serves to continually decrease their footprints environmentally, keep their stock healthy and subsequently pose little or no risk to wild salmon.

I wholeheartedly object to the view that a salmon farmer can't care about the environment and wild salmon and personally know a great number of people who act and feel the same way.

It is disappointing to hear the misinformed and incredibly positional views expressed here sometimes, I truly hope that in the years to come this issue will begin to take on a less hostile and untrusting feel when it comes to discussing the state of wild salmon in BC and the management of the aquaculture industry.

 

[Andrew P]

CK - It matter's who you are because knowing that you actually do work for Mainstream does make it a more credible source of information in my eyes.

It wasn't rocket surgery to figure out who you are....the first google search shows your name and twitter account, so obviously you are not trying to hide your identity, which is commendable, unlike others.

I am sure that the industry is more enviro friendly than ever before and will be more so in the future. But there has been a lot of shady things in the industry in the past and it scares the crap out of people when there is disease(and so it should). I think even more of the reason that people have a general distrust of the industry is because of the secrecy of both the industry and DFO.

Birdsnest - just because it is naturally occuring doesn't mean that it is safe to eat....and just because it is safe to eat now, doesn't mean it will be in the future because viruses evolve, that's just what they do. For the same reason it is not safe to eat bird flu chicken it is probably not a wise idea to eat fish flu salmon.

 

[Birdsnest]

There is a big difference between a bird and a cold water fish AP. My basic understanding of viral transmission between species shows that it is unlikely for a human to get a fish flue. The primary reason is body the great difference in body temperature. Birds, I believe generally have body temperatures slightly higher than ours. For this reason virus sharing is posable but even that slight difference in temp reduces the possibility of a shared virus posable. Please, anyone out there that has sockeye in their freezers, it is very possibly infected with IHN. Let me know and I will come remove it safely from your freezer to mine until i can dispose of it safely down my throat.

 

[Dave]

Please, anyone out there that has sockeye in their freezers, it is very possibly infected with IHN. Let me know and I will come remove it safely from your freezer to mine until i can dispose of it safely down my throat.

I can help with that as well, lol! Fraser River FN have been eating IHN infected sockeye for someting like 10,000 years.

 

[Andrew P]

Good to see see how concerned you guys are about disease in your fish, people eating diseased fish and the spread to and from the wild populations. IHN may be naturally occuringbut then it is unnaturally magnified in you pens and then transmitted back to the wild population. Seems like a cycle that would only increase the disease for all wouldn't you say?


I hope that I don't catch diseased wild fish, but if I do, I know where to send them. Obviously most of diseases can't be detected just by looking, but if I see a fish coming out of the water with big open sores it's all yours.

 

[Aces]

This debate is getting so old and I for one am pretty much through with debating these industry people. It seems that the anti side is a bunch of regular citizens who care about wild fish and the wild ecosystem and the pro side is for the most part PAID to post on here as part of their job.

I'm sorry but it is hard to listen to you ClayoquotKid as being just regular joe fish farmer....because that is not the case. Talk about follow the money hey?!

ClayoquotKid AKA Sustainability Officer for Mainstream Canada AKA A Division of EWOS Canada AKA Wholy owned by Cermaq AKA publicly traded on the Norwegian Stock Exchange. I am sure that you as a person are a nice guy but your marching orders do not have Canada's best interest in mind but rather shareholders interests in mind.

It may be completely by coincidence that the sustainability officer for Mainstream also uses this nickname....but it seems unlikely.

I was wondering how long it would take you guys to figure out who he was.

 

[ClayoquotKid]

Here is a study on IHN done with wild and hatchery Chinook: http://escholarship.org/uc/item/4cq1g6gd#page-1

They basically concluded that horizontal transfer was a low ecological risk, having held uninfected/infected fish at ratios of 1:20 for up to 24hrs - most of the infections were asymptomatic and it was only in dense populations where mucus was transferred (ie. hatcheries or farms where fish may nip at each other) that infections were more widespread.

The general idea is that within a farm a virus may spread rapidly, hence the quick reaction needed by farmers to identify it and either treat or remove the fish depending on what pathogen it is.

Going the other direction it is less likely for a virus to be transmitted from farmed to wild due to the decreased densities and spatial movement of fish.

I see this as supporting the view that when a viral outbreak of any nature is found on a farm and that farm is treated or depopulated as quickly as possible, it poses little risk to wild populations that may be in the area.

Responsible actions taken by farmers to protect their fish also protect wild fish.

The concern that a piscene virus may infect humans, or any other warm-blooded animal is unfounded - they have evolved to target cold-blooded fish and are killed at temperatures found in a human body.

 

[agentaqua]

Good to see see how concerned you guys are about disease in your fish, people eating diseased fish and the spread to and from the wild populations. IHN may be naturally occuring but then it is unnaturally magnified in you pens and then transmitted back to the wild population. Seems like a cycle that would only increase the disease for all wouldn't you say?

Andrew hit the nail on the head. That's EXACTLY the issue w parasite and disease transfer to wild stocks that CANNOT be mitigated using open net-cage technology.

And as these recently-infected wild stocks swim off, they later die unnoticed or the cause for the die-off remains unknown – and then CK can later declare to anyone that will listen that no one has been able to quantify the impact to his personal satisfaction in any "measurable" way, and it is up to the antis to somehow generate the information to change his industry-indoctrinated mind. Ignorance works for CK and his industry. Both get paid that way. Nobody has to make the effort to change.

This scenario is IN SPITE of the fact that it is up to the industry to prove they are NOT having an impact.

This is IN SPITE of the fact that the fish farming industry hides what inadequate fish health data they do generate.

This is IN SPITE of the fact that the government colludes with the industry to silence and intimidate independent scientists who wish to learn the truth.

 

[agentaqua]

IHN is of a lesser concern since it is a disease vector that Pacific salmon have co-evolved with and those species would develop some level of natural immunity against.

The same rationale for guarding against sea lice transfer would still apply though – as some stocks or species would have limited exposure to this specific disease vector at certain life history stages and specific sites. There is a succession of life history stages and species occupying specific sites in both freshwater and marine waters, and by holding disease vectors in one place year round, and by magnifying the release of those disease vector propagules – you could infect new, naive wild stocks.

For me, the greater risk is the introduction of a new disease vector (like ISA) where it would be expected that Pacific salmon would have a compromised immune response because there would be no “natural” immunity already developed.

 

[ClayoquotKid]

Andrew hit the nail on the head. That's EXACTLY the issue w parasite and disease transfer to wild stocks that CANNOT be mitigated using open net-cage technology.

And as these recently-infected wild stocks swim off, they later die unnoticed or the cause for the die-off remains unknown – and then CK can later declare to anyone that will listen that no one has been able to quantify the impact to his personal satisfaction in any "measurable" way, and it is up to the antis to somehow generate the information to change his industry-indoctrinated mind. Ignorance works for CK and his industry. Both get paid that way. Nobody has to make the effort to change.

This scenario is IN SPITE of the fact that it is up to the industry to prove they are NOT having an impact.

This is IN SPITE of the fact that the fish farming industry hides what inadequate fish health data they do generate.

This is IN SPITE of the fact that the government colludes with the industry to silence and intimidate independent scientists who wish to learn the truth.

Those are far from "facts" Aqua.

You can't prove a negative, and although you may feel that way - it simply isn't the way it works.

Our fish health data is far from inadequate, as Cohen noted, "the quality and quantity (in terms of breadth of data collected) of the fish health database are impressive, especially when compared with monitoring programs in other sectors."

He also stated, "the public has never had access to the kind of information that was made available during this Inquiry." and "DFO recognizes that transparency is an issue that needs to be addressed, and it has taken steps to provide more information to the public than has been available previously."

I do agree with his statement that, "The privilege of being allowed to conduct a business that poses risk to wild stocks should carry a concomitant requirement to provide access to government scientists for research purposes beyond the scope of routine monitoring. It is through such research that new discoveries are made which can lead to better monitoring and the implementation of better precautionary measures to protect wild stocks. Diseases and pathogens are dynamic; they evolve and adapt to their environment. Researchers and managers alike must be equipped to look for and deal with the unexpected in order to manage new risks to Fraser River sockeye proactively as soon as they develop."

This does not mean that people like Morton, Orr, Volpe, or the likes Staniford are entitled to get everything they ask for in their apparent crusade to end salmon farming - but professional fish pathologists, virologists and geneticists who have the capability to understand and utilize the data (I know you're going to bring up Miller here, I will try to find the info that shows why she did not end up getting samples for that particular project, pretty sure it was posted somewhere)

Lastly, proposing a collusion between industry and government is an easy out for opponents to fall back on when they don't get their way - if "independent scientists" wish to "learn the truth" they should work a little harder at following scientific protocols and less time making up scary stories that rehash what has already been scrutinized by professionals and dismissed as false.

 

[tincan]

Those are far from "facts" Aqua.

Lastly, proposing a collusion between industry and government is an easy out for opponents to fall back on when they don't get their way - if "independent scientists" wish to "learn the truth" they should work a little harder at following scientific protocols and less time making up scary stories that rehash what has already been scrutinized by professionals and dismissed as false.

CK, will you admit that collusion between industry and government has and is occurring? Do you think that anyone who suggests collusion is occurring is a 'radical' as Joe Oliver would like to label them?

Would you agree that the cigarette industry was/is in collusion with gov't for decades despite the deadly consequences of these actions?

Would you agree that oil & gas industry was/is in collusion with gov't in working to derail any sort of advancement in tech or science that didn't/doesn't work in it's favour?

Would you agree that the chemical/pesticide industry was/is in collusion with gov't despite the scientific evidence to suggest that CFC's and agent orange and toxic pesticides are really, really bad for us?

Would you agree that each of these industries worked very hard to suppress science and pay-off (through direct and indirect means) gov't to allow the status quo to remain so?

Do you not see any similarities with the above examples and what the open-net pen fish farming industry is doing now? Why did the fish farming industry feel the need to hire Hill & Knowlton to 'help' them out? This is the same company that was hired to deal with 'inconveniences' such as the exxon valdez spill, the backlash against the cigarette industry, the 'global warming hoax', that little thing at Tianamen sq .... the list goes on.

I realize that you are not here to answer these questions in a meaningful manner but rather to use the same strategies that Hill & Knowlton are paid millions of dollars to do by industry, which is to delay, deflect, and spin the argument in any way so long as it takes the attention away from the actual issues. Like many on this forum, I am well aware of these tactics that have worked well for the industries listed above... at least until the public consensus finally was reached only after untold devastation, death and financial messes to be paid for by the public. I am not an 'anti-industry' person by any stretch of the imagination. I want industry in BC and throughout the world that is sustainable and accountable for its actions. The current model used by your industry does NOT meet my criteria in it's current form.

 

[GLG]

IHN is of a lesser concern since it is a disease vector that Pacific salmon have co-evolved with and those species would develop some level of natural immunity against.

I'm not so sure I would agree with you on that one. IHN virus life cycle has evolved over millions of years. That said man has inserted the fish feedlot into this life cycle and has given this virus a clear advantage over the native wild salmon. It should be noted that IHN affects herring as well and we all know that springs do like to eat herring.

 

[agentaqua]

You can't prove a negative, and although you may feel that way - it simply isn't the way it works.

I agree that it hasn't been the way it has worked with the fish farms for over 30 years now – that they have had a free ride and have avoided performing a full environmental assessment for the past 30 years now due to the interference of the Commissioner for Aquaculture Development, and collusion within DFO. Haven't you been reading the past 10 pages of postings, or so wrt siting criteria and fish health?

Our fish health data is far from inadequate..

TOTAL BS CK. Haven't you been reading the past 10 pages or so? I reiterate and detail the gaps in the fish health monitoring:

1/ Farm data is not publicly available,
2/ Farm data is not publicly-available on a site-specific basis,
3/ Farm data on fish health goes through the filter of the provincial fish vet who gets to decide whether or not to test for certain diseases. There is no third party monitoring or public oversight,
4/ The office of the provincial fish vet protects the farms by withholding farm-specific fish health data from the public,
5/ The fish farms, their association and their lawyers have been successful in obstructing inspectors and in the release of fish health records,
6/ There is a unnecessary and irresponsible time delay between noticing, reporting and investigation of symptoms and between initiation of control procedures of days to weeks while transfer of disease vectors continues between cultured and wild stocks. Response time is critical when dealing with highly migratory stocks,
7/ The testing for “confirmation” of disease vectors like ISA as dictated by CFIA testing protocols (i.e. The PCR method) requires a testing protocol that can only test for known strains of known diseases. This testing protocol is ineffective in recognizing introduced and emerging diseases like ISA,
8/ There is no public notification system for outbreaks,
9/ Adjacent wild stocks are not concurrently tested in association with a disease outbreak,
10/ Wild stocks have not been adequately tested as part of an ongoing monitoring program,
11/ There is no way for public input to be systematically utilized in the development of disease response plans and CFIA wants the public to know as little as possible about diseases on fish farms,
12/ There is no scientifically-defensible disease response plans because proper siting criteria has NOT been utilized in the aquaculture tenure applications,
13/ We do not know enough about infection dynamics, epidemiology, persistence and life cycles of both known and emerging diseases in order to complete proper risk assessments and to initiate risk reduction measures for protection of wild stocks,
14/ Risk assessments for each disease have not been performed,
15/ Risk assessments for each farm site have not been performed,
16/ Other fish health response procedures not yet identified, consulted and completed include: Environmental Impact Policy, cost-benefit analysis of alternative control/eradication strategies, predictive modeling, retrospective analysis, contingency planning, risk of disease transmissions, establishing incident plans, monitoring effectiveness of control measures, resource planning, and incident response training,
17/ Other fish health responses not identified to the public include: procedure for notifying and consulting First Nations and the public about a disease affecting cultured stocks after a veterinary inspector has been notified, follow-up actions such as biocontainment and movement controls, quarantine orders, setting the limits of the disease Control Area, and disposal and disinfection activities.

YET you claim this is all “adequate” enough for you and your industry, CK. I guess it is adequate enough for you. Not for me, however. Not for the rest of the public, either. And not enough for protection of our wild stocks, irrespective of the claims of the industry hacks.

 

[ClayoquotKid]

I agree that it hasn't been the way it has worked with the fish farms for over 30 years now – that they have had a free ride and have avoided performing a full environmental assessment for the past 30 years now due to the interference of the Commissioner for Aquaculture Development, and collusion within DFO. Haven't you been reading the past 10 pages of postings, or so wrt siting criteria and fish health?TOTAL BS CK. Haven't you been reading the past 10 pages or so? I reiterate and detail the gaps in the fish health monitoring:

1/ Farm data is not publicly available,
2/ Farm data is not publicly-available on a site-specific basis,
3/ Farm data on fish health goes through the filter of the provincial fish vet who gets to decide whether or not to test for certain diseases. There is no third party monitoring or public oversight,
4/ The office of the provincial fish vet protects the farms by withholding farm-specific fish health data from the public,
5/ The fish farms, their association and their lawyers have been successful in obstructing inspectors and in the release of fish health records,
6/ There is a unnecessary and irresponsible time delay between noticing, reporting and investigation of symptoms and between initiation of control procedures of days to weeks while transfer of disease vectors continues between cultured and wild stocks. Response time is critical when dealing with highly migratory stocks,
7/ The testing for “confirmation” of disease vectors like ISA as dictated by CFIA testing protocols (i.e. The PCR method) requires a testing protocol that can only test for known strains of known diseases. This testing protocol is ineffective in recognizing introduced and emerging diseases like ISA,
8/ There is no public notification system for outbreaks,
9/ Adjacent wild stocks are not concurrently tested in association with a disease outbreak,
10/ Wild stocks have not been adequately tested as part of an ongoing monitoring program,
11/ There is no way for public input to be systematically utilized in the development of disease response plans and CFIA wants the public to know as little as possible about diseases on fish farms,
12/ There is no scientifically-defensible disease response plans because proper siting criteria has NOT been utilized in the aquaculture tenure applications,
13/ We do not know enough about infection dynamics, epidemiology, persistence and life cycles of both known and emerging diseases in order to complete proper risk assessments and to initiate risk reduction measures for protection of wild stocks,
14/ Risk assessments for each disease have not been performed,
15/ Risk assessments for each farm site have not been performed,
16/ Other fish health response procedures not yet identified, consulted and completed include: Environmental Impact Policy, cost-benefit analysis of alternative control/eradication strategies, predictive modeling, retrospective analysis, contingency planning, risk of disease transmissions, establishing incident plans, monitoring effectiveness of control measures, resource planning, and incident response training,
17/ Other fish health responses not identified to the public include: procedure for notifying and consulting First Nations and the public about a disease affecting cultured stocks after a veterinary inspector has been notified, follow-up actions such as biocontainment and movement controls, quarantine orders, setting the limits of the disease Control Area, and disposal and disinfection activities.

YET you claim this is all “adequate” enough for you and your industry, CK. I guess it is adequate enough for you. Not for me, however. Not for the rest of the public, either. And not enough for protection of our wild stocks, irrespective of the claims of the industry hacks.

Maybe if you'd stop with the name calling, I might take more time to address your 17 points in all their inaccuracy, absurdity and over-the-top expectations.

Much of what you state there is ( in your words) total BS, or is happening despite your claims otherwise and after more than 30 years of operations without any measurable impacts on wild salmon being shown, much of what you propose is purely the pipe-dream of an opponent who would engage a perverse vision of the precautionary principle to ensure absolutely nothing happens anywhere - except of course the killing of wild salmon for sport and money, which is perfectly acceptable and has zero impact...

Nothing can be said or done which will appease your position, so I'm going to cut this short and go have a beer instead of typing any more.

 

[Birdsnest]

YET you claim this is all “adequate” enough for you and your industry, CK. I guess it is adequate enough for you. Not for me, however. Not for the rest of the public, either. And not enough for protection of our wild stocks, irrespective of the claims of the industry hacks.

I'm sure you may speak for some here but just out of curiosity how is it that you feel you speak for the public? Do you do this for a living or is it just pure passion?

 

[Charlie]

Maybe if you'd stop with the name calling, I might take more time to address your 17 points in all their inaccuracy, absurdity and over-the-top expectations.Much of what you state there is ( in your words) total BS, or is happening despite your claims otherwise and after more than 30 years of operations without any measurable impacts on wild salmon being shown, much of what you propose is purely the pipe-dream of an opponent who would engage a perverse vision of the precautionary principle to ensure absolutely nothing happens anywhere - except of course the killing of wild salmon for sport and money, which is perfectly acceptable and has zero impact...Nothing can be said or done which will appease your position, so I'm going to cut this short and go have a beer instead of typing any more.

Yep… please go have a “beer”!Oh… btw it has been over a “week” and still haven’t seen any response to “ a week to point out all the wrongs in that post.”?

Whoo boy, Charlie.It's gonna take me a week to point out all the wrongs in that post.You've hit about every single fallacy and piece of misinformation used against aquaculture out there.

Would you mind pointing out how, “You've hit about every single fallacy and piece of misinformation used against aquaculture out there.”?

 

[Charlie]

Oh… BTW
Your reference is completely out of context and if YOU know anything about IHNv is completely BS!!

Here is a study on IHN done with wild and hatchery Chinook: http://escholarship.org/uc/item/4cq1g6gd#page-1

They basically concluded that horizontal transfer was a low ecological risk, having held uninfected/infected fish at ratios of 1:20 for up to 24hrs - most of the infections were asymptomatic and it was only in dense populations where mucus was transferred (ie. hatcheries or farms where fish may nip at each other) that infections were more widespread.

The general idea is that within a farm a virus may spread rapidly, hence the quick reaction needed by farmers to identify it and either treat or remove the fish depending on what pathogen it is.

Going the other direction it is less likely for a virus to be transmitted from farmed to wild due to the decreased densities and spatial movement of fish.

I see this as supporting the view that when a viral outbreak of any nature is found on a farm and that farm is treated or depopulated as quickly as possible, it poses little risk to wild populations that may be in the area.

Responsible actions taken by farmers to protect their fish also protect wild fish.

Do you know the difference between IHNv being “asymptomatic” versus “symptomatic”?
Do you know there are THREE different strains of IHNV we deal with here in the Pacific Northwest?
Do you realize that study you referenced only is dealing with the California strain of IHNv?

You might want to do some research on the “U clade” found in Alaska, British Columbia, Washington, Oregon and the “M clade” that is present in southern Idaho before claiming “Responsible actions taken by farmers to protect their fish also protect wild fish”?

In that report referenced, they are clear their study is on the “Sacramento River strain of IHNV” (emphasis added):

“Horizontal transmission of the Sacramento River strain of IHNV from infected juvenile hatchery fish to wild cohorts would appear to be a low ecological risk. The study results demonstrate key differences between IHNV infections as present in a hatchery and the natural environment. These differences should be considered during risk assessments of the impact of IHNV infections on wild salmon and trout populations.

“These studies showed that asymptomatic infections will occur when a salmon is exposed for as little as 1 min to >102 pfu mL-1, yet progression to clinical disease is infrequent unless the challenge dose is >104 pfu mL-1. Asymptomatic infections were detected up to 39 d post-challenge. No virus was detected by tissue culture in natural Chinook juveniles cohabitated with experimentally IHNV-infected hatchery Chinook at ratios of 1:1, 1:10, and 1:20 for either 5 min or 24 h. Horizontal transmission of the Sacramento River strain of IHNV from infected juvenile hatchery fish to wild cohorts would appear to be a low ecological risk. The study results demonstrate key differences between IHNV infections as present in a hatchery and the natural environment. These differences should be considered during risk assessments of the impact of IHNV infections on wild salmon and trout populations.

“Strains of IHNV found in the upper Sacramento River are related to a larger group of isolates, referred to as the L clade, obtained from the southern coastal areas of Oregon and anadromous fish waters of northern California (Kurath and others 2003). These viruses are one of three clades of IHNV. The U clade is found in Alaska, British Columbia, Washington, Oregon and the M clade is present in the southern Idaho commercial rainbow trout (O. mykiss) industry. Virus isolates in the L clade share similar electrophoretic profiles for their structural proteins and when grouped by this method are considered electropherotype 3 (Hsu and others 1986). Isolates in the L clade also demonstrate a degree of host specificity with a tendency to be more virulent for Chinook salmon then rainbow trout (G. Kelley, pers. comm.; LaPatra and others 1990). In California, IHNV is most commonly detected in sexually mature Chinook salmon and steelhead that show no clinical signs of disease but potentially contain high concentrations of virus in the ovarian fluid or semen at the time of spawning.

“We cannot accurately predict the outcome of these infections as both external tissues (gill and skin) and internal organs were pooled for viral samples. Given the low virulence observed in laboratory challenges, it is possible that epidermal infections may not always lead to systemic disease.

“Other researchers have documented that epiderma cells of the skin, gill, and esophagus are the initial sites of viral replication following waterborne challenges (Mulcahy and others 1983; Yamamoto and others 1992; Drolet and
others 1994; Helmick and others 1995). Laboratory trials by Yamamoto and others (1992) demonstrated an early involvement of gill and epidermal tissues following waterborne exposures of rainbow trout to higher dose challenges of IHNV. They concluded that virus may undergo some replication in these tissues as early as 1 dpe, then spread to internal organs which begin to show positive for the virus at 3 dpe and thereafter. LaPatra and others (1989) reported that virus concentrations in the mucus increased from 24 to 48 h post-challenge suggesting replication was occurring in the epidermis.

“In our studies, gill tissues were positive in fish up to 39 d, a time point well past the sampling dates in the studies by Yamamoto and others (1992). While the gills and skin were viewed as more initial and transient locations for virus replication in rainbow trout, we speculate that in Chinook salmon juveniles these tissues may remain infected for longer periods of time and perhaps support virus growth in the absence of an extended involvement of internal organs.

“There was a distinct difference between the mortality observed during hatchery epizootics and our experimental viral challenges. We demonstrated that environmentally relevant challenges (1 min at 102 and 103 pfu mL-1) incurred a high incidence of asymptomatic infections yet relatively low mortality (<9% in 19 dpe) Extended exposure at high virus concentrations (>104 pfu mL-1) and high densities of hosts may be required for disease amplification as the Sacramento River strain of IHNV shows relatively low virulence. In the 1997 laboratory challenge studies, we showed that 30 min static bath challenges with 5.7 x 103 pfu mL-1 produced only 10% cumulative mortality over 19 d. This challenge concentration of 1,000 pfu mL-1 may at times be environmentally relevant, particularly in high fish density situations, as this viral load was shown to be released into the water by clinically infected smolts.

The concern that a piscene virus may infect humans, or any other warm-blooded animal is unfounded - they have evolved to target cold-blooded fish and are killed at temperatures found in a human body.

That is a nice twist... "The concern that a piscine virus may infect humans" ???

 

[rockdog]

Zero point in debating any of these feed lot workers. They work in the industry, and are paid to never agree. Absolute waste of time responding to these guys.
All I can say is, I sure hope for all of our children's sake, and BC as a whole, that this brutally disgusting industry disappears........the sooner the better!
Done on this thread.
Out

 

[Birdsnest]

Whatever CK, you will never agree, as you are paid not to. Pay me, and I'll defend whatever you want me to. What a joke. Go back to throwing slice in the water!

Its obvious why you believe he is paid to post her for your clearly state you will defend anything for money yourself! peoples belief systems are a product of their own capabilities. Are you really willing to debate something you personally beleive is false regardless of the topic for money? I find this very interesting about you.