Fish Farms

[agentaqua]

ORIGINAL RESEARCH
Open Access
Transmission routes maintaining a viral pathogen of steelhead trout within a complex multi‐host assemblage
Rachel Breyta
Ilana Brito
Paige Ferguson
Gael Kurath
Kerry A. Naish
Maureen K. Purcell
Andrew R. Wargo
Shannon LaDeau
First published: 06 September 2017
https://sci-hub.tw/10.1002/ece3.3276

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Abstract
This is the first comprehensive region wide, spatially explicit epidemiologic analysis of surveillance data of the aquatic viral pathogen infectious hematopoietic necrosis virus (IHNV) infecting native salmonid fish. The pathogen has been documented in the freshwater ecosystem of the Pacific Northwest of North America since the 1950s, and the current report describes the disease ecology of IHNV during 2000–2012. Prevalence of IHNV infection in monitored salmonid host cohorts ranged from 8% to 30%, with the highest levels observed in juvenile steelhead trout. The spatial distribution of all IHNV‐infected cohorts was concentrated in two sub‐regions of the study area, where historic burden of the viral disease has been high. During the study period, prevalence levels fluctuated with a temporal peak in 2002. Virologic and genetic surveillance data were analyzed for evidence of three separate but not mutually exclusive transmission routes hypothesized to be maintaining IHNV in the freshwater ecosystem. Transmission between year classes of juvenile fish at individual sites (route 1) was supported at varying levels of certainty in 10%–55% of candidate cases, transmission between neighboring juvenile cohorts (route 2) was supported in 31%–78% of candidate cases, and transmission from adult fish returning to the same site as an infected juvenile cohort was supported in 26%–74% of candidate cases. The results of this study indicate that multiple specific transmission routes are acting to maintain IHNV in juvenile fish, providing concrete evidence that can be used to improve resource management. Furthermore, these results demonstrate that more sophisticated analysis of available spatio‐temporal and genetic data is likely to yield greater insight in future studies.

 

[agentaqua]

OPEN ACCESS
PEER-REVIEWED
RESEARCH ARTICLE

Phylogenetic Evidence of Long Distance Dispersal and Transmission of Piscine Reovirus (PRV) between Farmed and Wild Atlantic Salmon

• https://doi.org/10.1371/journal.pone.0082202

Abstract
The extent and effect of disease interaction and pathogen exchange between wild and farmed fish populations is an ongoing debate and an area of research that is difficult to explore. The objective of this study was to investigate pathogen transmission between farmed and wild Atlantic salmon (Salmo salarL.) populations in Norway by means of molecular epidemiology. Piscine reovirus (PRV) was selected as the model organism as it is widely distributed in both farmed and wild Atlantic salmon in Norway, and because infection not necessarily will lead to mortality through development of disease. A matrix comprised of PRV protein coding sequences S1, S2 and S4 from wild, hatchery-reared and farmed Atlantic salmon in addition to one sea-trout (Salmo truttaL.) was examined. Phylogenetic analyses based on maximum likelihood and Bayesian inference indicate long distance transport of PRV and exchange of virus between populations. The results are discussed in the context of Atlantic salmon ecology and the structure of the Norwegian salmon industry. We conclude that the lack of a geographical pattern in the phylogenetic trees is caused by extensive exchange of PRV. In addition, the detailed topography of the trees indicates long distance transportation of PRV. Through its size, structure and infection status, the Atlantic salmon farming industry has the capacity to play a central role in both long distance transportation and transmission of pathogens. Despite extensive migration, wild salmon probably play a minor role as they are fewer in numbers, appear at lower densities and are less likely to be infected. An open question is the relationship between the PRV sequences found in marine fish and those originating from salmon.

 

[agentaqua]

is the strain from farms different than the strain found here? I am thinking nature developed defences for the native strain...
our fish are getting smallpox equivalent.

S1 strain - same as the FF fish...no surprise there...
https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0141475&type=printable

"PRV positive samples from fish derived from Alaska, British Columbia and Washington State share identical sequence types. Comparative analysis of the phylogenetic tree indicated that Canada/US Pacific Northwest sequences formed a subgroup with some Norwegian sequence types (group II), distinct from other Norwegian and Chilean sequences (groups I, III and IV)."

 

[agentaqua]

OPEN ACCESS
PEER-REVIEWED
RESEARCH ARTICLE

First Description of a New Disease in Rainbow Trout (Oncorhynchus mykiss(Walbaum)) Similar to Heart and Skeletal Muscle Inflammation (HSMI) and Detection of a Gene Sequence Related to Piscine Orthoreovirus (PRV)

• https://doi.org/10.1371/journal.pone.0131638

Abstract
In fall 2013, anorexia, lethargy and mortalities up to 10-12,000 dead fish per week were observed in rainbow troutOncorhynchus mykissin three fresh water hatcheries (salinity 0-1 ‰) on the west coast of Norway. The fish (25-100 g) showed signs of circulatory failure with haemorrhages, ascites and anaemia. The histopathological findings comprised inflammation of the heart and red muscle and liver necrosis. The affected fish had a common origin. Disease and mortalities were also observed up to four months after sea water transfer. Microbiological examination did not reveal presence of any known pathogens. Based on histopathological similarities to heart and skeletal inflammation (HSMI) in Atlantic salmon, associated with piscine orthoreovirus (PRV), extended investigations to detect a virus within the familyReoviridaewere conducted. By the use of primer sets targeting the PRV genome, a sequence with 85% identity to a part of segment S1 of PRV was obtained. Further analysis showed that the virus sequence could only be aligned with PRV and no other reoviruses both on amino acid and nucleotide level. Two PCR assays were developed for specific detection of the virus. High amounts of the virus were detected in diseased fish at all affected farms and low amounts were detected in low prevalence at the broodfish farms. Further investigations are needed to determine if the virus is associated with the new disease in rainbow trout and to further characterize the virus with respect to classification, relationship with PRV, virulence, pathology and epidemiology.

 

[agentaqua]

• https://doi.org/10.1139/facets-2018-0008
  The same strain ofPiscine orthoreovirus(PRV-1) is involved in the development of different, but related, diseases in Atlantic and Pacific Salmon in British Columbia
  Published Online
  18 June 2018
  | Views
  432
  • Emiliano Di Ciccoemiliano.dicicco@dfo-mpo.gc.ca
  • Hugh W. Ferguson
  • Karia H. Kaukinen
  • Angela D. Schulze
  • Shaorong Li
  • Amy Tabata
  • Oliver P. Günther
  • Gideon Mordecai
  • Curtis A. Suttle
  • Kristina M. MillerKristi.Saunders@dfo-mpo.gc.ca
  • PDF
  • Citation (RIS)
  • Citation (BibTeX)

Abstract

Piscine orthoreovirusStrain PRV-1 is the causative agent of heart and skeletal muscle inflammation (HSMI) in Atlantic salmon (Salmo salarLinnaeus, 1758). Given its high prevalence in net pen salmon, debate has arisen on whether PRV poses a risk to migratory salmon, especially in British Columbia (BC) where commercially important wild Pacific salmon are in decline. Various strains of PRV have been associated with diseases in Pacific salmon, including erythrocytic inclusion body syndrome (EIBS), HSMI-like disease, and jaundice/anemia in Japan, Norway, Chile and Canada. We examined the developmental pathway of HSMI and jaundice/anemia associated with PRV-1 in farmed Atlantic and chinook (Oncorhynchus tshawytscha(Walbaum, 1792)) salmon in BC, respectively. In situ hybridization localized PRV-1 within developing lesions in both diseases. The two diseases showed dissimilar pathological pathways, with inflammatory lesions in heart and skeletal muscle in Atlantic salmon and degenerative-necrotic lesions in kidney and liver in chinook salmon, plausibly explained by differences in PRV load tolerance in red blood cells. Viral genome sequencing revealed no consistent differences in PRV-1 variants intimately involved in the development of both diseases suggesting that migratory chinook salmon may be at more than a minimal risk of disease from exposure to the high levels of PRV occurring in salmon farms.

 

[bones]

That thing on the back of fish is called a tail, bones. Fish swim. Fish swim and intermingle with other fish that swim. Would've thought you would have had the background and experience with fish to easily recognize those realities. I am confident most other posters on this forum would not have need of being reminded of these realities.

From page 78 of the thesis: "An adult Rivers Inlet sockeye salmon testing positive for PRV in 2014 yielded a sequence for genome segment S1 which was a 99% sequence match to GenBank sequence KC473452 (E = 0) isolated from an Atlantic salmon from BC’s Discovery Islands, indicating an epidemiological link to PRV outside this system."

But.... But can you answer the question?
How does a fish contract a virus that isn't near them? Are you suggesting that dolly varden migrate past fish farms?
Rainbow trout? Do they even migrate? I thought trout were freshwater species. The more fish species you post here that have prv the easier it is to believe that prv is a natural virus....... What's next? Westslope cutthroat?

 

[bones]

O.... And AA I just looked at the list of fish that rockdog plugged and dolly and rainbow trout weren't there. Weird all the fish that swim into the net pens to feed on plankton and none are trout.

 

[california]

But.... But can you answer the question?
How does a fish contract a virus that isn't near them? Are you suggesting that dolly varden migrate past fish farms?
Rainbow trout? Do they even migrate? I thought trout were freshwater species. The more fish species you post here that have prv the easier it is to believe that prv is a natural virus....... What's next? Westslope cutthroat?

Eulachon are anadromous, so all go to salt water and could be in contact with fish farms directly. While Some Dolly Varden go to sea for varying times, a more plausible route of infection for them would be contact with or eating the eggs of infected returning pacific salmon

 

[rockdog]

But.... But can you answer the question?
How does a fish contract a virus that isn't near them? Are you suggesting that dolly varden migrate past fish farms?
Rainbow trout? Do they even migrate? I thought trout were freshwater species. The more fish species you post here that have prv the easier it is to believe that prv is a natural virus....... What's next? Westslope cutthroat?

Wow Fabian, how about just read the articles rather than trying to run around in a circle all the time. The information is all there. There is a lot of information in there and you should find your answers.

 

[bones]

Eulachon are anadromous, so all go to salt water and could be in contact with fish farms directly. While Some Dolly Varden go to sea for varying times, a more plausible route of infection for them would be contact with or eating the eggs of infected returning pacific salmon

Thank you and I know what Eulachon are other than great bait. How do rainbow get infected? And isn't this just theoretical science? In other words, this is all in a lab isn't it? If its not were are the samples taken from?s

 

[bones]

Wow Fabian, how about just read the articles rather than trying to run around in a circle all the time. The information is all there. There is a lot of information in there and you should find your answers.

Still cant answer one question..eh? So you feel the need to call people names and throw sand? It's not helping your cause. Good thing the as you call us "fish farm supporters" dont lower themselves to your level.

 

[agentaqua]

bones has inadvertently let the cat out of the bag - this isn't "theoretical" science. It is results from a multi-year field project. The implications of these findings should make us all sit and think about this for a moment:

1/ An introduced Norwegian disease has been released into wild fish and their freshwater ecosystems many kilometers away from fish farms - and the only plausible culprit are the open net-cage operations stocked with farmed fish. Siting criteria are a sham.
2/ This has been proven despite the best efforts to hide fish farm health data from the public and independent researchers. The regulators and an inadequate system of pandering to industry have failed us time and time again.
3/ We ain't getting rid of this one folks! This disease vector (and others) are here to stay. The barn door is open and those horses fled long ago - along with their associated horse-puckies.
4/ It is long past time to assume either the regulators or spokespersons from the industry they protect tell the truth or can be trusted.
5/ What now? Closed containment?

 

[rockdog]

Still cant answer one question..eh? So you feel the need to call people names and throw sand? It's not helping your cause. Good thing the as you call us "fish farm supporters" dont lower themselves to your level.

Actually Fabian, you were the one that could not answer a simple question. The question as a refresher was "do you think the massive sea lice outbreak on the Clayoquot farms, which coincided with the out migration of smolts, had a negative impact on smolt survival?"
You never answered that question. A simple yes or no will do.

Do I think you are a fish farm supporter? I'm not sure. If you weren't hired by farms I doubt you would be advocating so strongly.

 

[rockdog]

For those that aren't sure what I'm talking about, that last sentence from Fabians (bones) website is the one that explains it...

 

[agentaqua]

Ya rockdog - there has been quite a few industry spokespersons & their associated PR consultants posting on this forum over the years - trying to mitigate the implications of the science critical of the status quo of maintaining the open net-pen industry as it currently is. That illogical defense also exposes the corruption and collusion from our regulators and the politicians in the defense of this industry. Once you did into this stuff - it's a rude awakening as to how the crooks actually run the show behind the scenes.

 

[agentaqua]

Will new fisheries minister respect salmon science?
http://policyoptions.irpp.org/magaz...ew-fisheries-minister-respect-salmon-science/

 

[agentaqua]

Pacific Salmon Foundation, 300 - 1682 West 7th Avenue, Vancouver, BC V6J 4S

Dr. Carmel Lowe,
Region Director of Science, Pacific Region Department of Fisheries and Oceans,
3190 Hammond Bay Road, Nanaimo, B.C. V9T 6N7

RE: Centre for Science Advice Pacific, report on PRV - jaundice study review, June 2018

July 30, 2018

Dear Dr. Lowe:

As a partner in the Strategic Salmon Health Initiative undertaken by Genome BC, DFO Science and the Pacific Salmon Foundation, I support having the best possible scientific review of our SSHI findings. However, I must address concerns over a recent internal report that presents DFO Science Advice in response to a request submitted by DFO Aquaculture Management Division. I am referring to an evaluation of the relevance of the Di Cicco et al. 20181 publication to the testing and management of PRV in British Columbia; signed by yourself on June 27, 2018. My concern for this process/report is not the request for regulatory advice, but for the review process and exclusion of the primary authors or any independent reviewers.

During my career within DFO, I don’t recall such a rapid response process, but the process is now clearly presented on the CSAS/SCCS website ((http://www.dfo‐mpo.gc.ca/csas-sccs/process‐processus/srp‐prs‐eng.htm). Unfortunately, the minimum standards described in these guidelines have not been adhered to in this example; and are at odds with government commitment to open, objective and transparent science. Further, in non‐government circles, this will again be criticized as contrary to a precautionary approach.

Most concerning to me, was that no advice on the relevance of the study findings to PRV testing and management in BC, was requested from the DFO‐affiliated researchers that authored the Di Cicco et al. 2018 study. The study authors were not informed of this review and they were not provided the opportunity to respond to criticisms of their study methods. This is more troubling since the CSA report is internal and does not receive peer review like the publication in question did. Since I received the CSA report for persons outside of DFO Science, I must assume the criticisms and recommendations in the report are now in the public. Certainly, the reports has now unfairly led to targeted comments in the media about the Di Cicco et al. paper and researchers involved.

1 Di Cicco, E., et al. 2018. The same strain of Piscine orthoreovirus (PRV) is involved with the development of different, but related, diseases in Atlantic and Pacific Salmon in British Columbia. FACETS 3: 599‐641

Consequently, I have asked the authors to comment on the review content and I provide a summary of their comments for your consideration (attached). Following the SSHI report on PRV/HSMI in Atlantic salmon in 2017, the logical next question for people was the risk of PRV to Pacific salmon. The Di Cicco et al. (2018) study of cultured Chinook salmon using audits samples already assessed by DFO, demonstrates the susceptibility of Chinook salmon to PRV and its expression as Jaundice/anemia. Given these observations and the potential risks to Pacific salmon, and the comments attached, I submit that the recommendations in the CSA review should not be accepted and that a more thorough scientific review is necessary and appropriate.

Yours Truly,

Brian E Riddell, PhD.
CEO/President, Pacific Salmon Foundation, and Project Co‐Lead, Strategic Salmon Health Initiative

 

[wildmanyeah]

Pacific Salmon Foundation, 300 - 1682 West 7th Avenue, Vancouver, BC V6J 4S

Dr. Carmel Lowe,
Region Director of Science, Pacific Region Department of Fisheries and Oceans,
3190 Hammond Bay Road, Nanaimo, B.C. V9T 6N7

RE: Centre for Science Advice Pacific, report on PRV - jaundice study review, June 2018

July 30, 2018

Dear Dr. Lowe:

As a partner in the Strategic Salmon Health Initiative undertaken by Genome BC, DFO Science and the Pacific Salmon Foundation, I support having the best possible scientific review of our SSHI findings. However, I must address concerns over a recent internal report that presents DFO Science Advice in response to a request submitted by DFO Aquaculture Management Division. I am referring to an evaluation of the relevance of the Di Cicco et al. 20181 publication to the testing and management of PRV in British Columbia; signed by yourself on June 27, 2018. My concern for this process/report is not the request for regulatory advice, but for the review process and exclusion of the primary authors or any independent reviewers.

During my career within DFO, I don’t recall such a rapid response process, but the process is now clearly presented on the CSAS/SCCS website ((http://www.dfo‐mpo.gc.ca/csas-sccs/process‐processus/srp‐prs‐eng.htm). Unfortunately, the minimum standards described in these guidelines have not been adhered to in this example; and are at odds with government commitment to open, objective and transparent science. Further, in non‐government circles, this will again be criticized as contrary to a precautionary approach.

Most concerning to me, was that no advice on the relevance of the study findings to PRV testing and management in BC, was requested from the DFO‐affiliated researchers that authored the Di Cicco et al. 2018 study. The study authors were not informed of this review and they were not provided the opportunity to respond to criticisms of their study methods. This is more troubling since the CSA report is internal and does not receive peer review like the publication in question did. Since I received the CSA report for persons outside of DFO Science, I must assume the criticisms and recommendations in the report are now in the public. Certainly, the reports has now unfairly led to targeted comments in the media about the Di Cicco et al. paper and researchers involved.

1 Di Cicco, E., et al. 2018. The same strain of Piscine orthoreovirus (PRV) is involved with the development of different, but related, diseases in Atlantic and Pacific Salmon in British Columbia. FACETS 3: 599‐641

Consequently, I have asked the authors to comment on the review content and I provide a summary of their comments for your consideration (attached). Following the SSHI report on PRV/HSMI in Atlantic salmon in 2017, the logical next question for people was the risk of PRV to Pacific salmon. The Di Cicco et al. (2018) study of cultured Chinook salmon using audits samples already assessed by DFO, demonstrates the susceptibility of Chinook salmon to PRV and its expression as Jaundice/anemia. Given these observations and the potential risks to Pacific salmon, and the comments attached, I submit that the recommendations in the CSA review should not be accepted and that a more thorough scientific review is necessary and appropriate.

Yours Truly,

Brian E Riddell, PhD.
CEO/President, Pacific Salmon Foundation, and Project Co‐Lead, Strategic Salmon Health Initiative

Can we have the other side of the story please I know you have it

 

[fogged in]

Exactly what other side are you looking for?
I assume you are asking the Fish Farm guys to post...right????

 

[wildmanyeah]

Exactly what other side are you looking for?
I assume you are asking the Fish Farm guys to post...right????

The original letter and review to which Riddell is responding too.