Pacific salmon not affected by lice:study

[Sushihunter]

Pacific salmon not affected by lice:study​

Last Updated: Monday, December 13, 2010 | 3:01 PM ET ​

CBC News ​

The decline in wild Pacific salmon populations is not likely caused by sea lice acquired from farmed salmon, a study released Monday suggests.

The findings of the study headed by Gary Marty, a professor at the University of California, suggest that the number of wild salmon that return to spawn in the fall can predict the number of sea lice that will be found on farmed salmon the following spring, which, in turn, predicts the extent of sea lice infestations in young wild salmon.​

A new study concluded that other factors besides lice might have contributed to the drastic decline among spawning Pacific salmon in 2002. (Jonathan Hayward/Canadian Press)​

However, the survival of wild salmon populations appears unrelated to the number of lice found on farmed fish or to farm fish production.​

Some experts have argued that separating farmed and wild salmon would help wild populations rebound, but this latest study suggests that is not the case.​

"Separating farm salmon from wild salmon — proposed through co-ordinated fallowing or closed containment — will not increase wild salmon productivity and that medical analysis can improve our understanding of complex issues related to aquaculture sustainability," study researchers wrote in their report.​

They concluded that other factors, including environmental stress or bacterial and viral infections, might have contributed to the alarming decrease in salmon populations in 2002.​

"Productivity of wild salmon is not negatively associated with either farm lice numbers or farm fish production, and all published field and laboratory data support the conclusion that something other than sea lice caused the population decline in 2002," they wrote in the report.​

Exposure to sea lice from farmed Atlantic salmon was thought to be the cause of the decline among the spawning fish. Record high numbers of pink salmon returned to spawn in rivers of the Broughton Archipelago in 2000 and 2001, but the returns were followed by a population decline of 97 per cent in 2002 and 88 per cent in 2003.​

Fluctuating salmon populations has been a source of concern among politicians and researchers for years.​

Earlier this year, British Columbia launched a probe into the disappearance of almost 10 million fish from the 2009 Fraser River sockeye run. That year only about one million fish returned to spawn, prompting the federal government to order an investigation led by B.C. Supreme Court Justice Bruce Cohen.​

As part of their study, Marty, along with associates Sonja Saksida, from the British Columbia Centre for Aquatic Health Sciences in Campbell River, B.C., and Terrance Quinn, from the University of Alaska, analyzed 10 to 20 years of fish farm data and 60 years of pink salmon data.​

Data showed that the number of pink salmon returning to spawn in the fall predicts the number of female sea lice on farm fish the next spring. This, the researchers said, accounts for 98 per cent of the annual variability in the prevalence of sea lice on outmigrating wild juvenile salmon.​

The researchers suggested that "determination of the causes of salmon population decline requires investigation of other variables."​

They noted that in 2001, sick juvenile pink salmon frequently had "bleeding at the base of the fins," but, the lesions did not occur in pink salmon exposed to sea lice under controlled laboratory conditions.​

Instead, the reddening of the fins was "commonly associated with stressful environmental conditions or bacterial and viral infections." However, none of these differentials were studied in 2001 and "their potential role in fish mortality that year remains unknown."​

"Adding medical analysis to multidisciplinary investigations of fish population decline can increase our understanding of the cause and help government agencies develop cost-effective regulations to sustain healthy wild salmon populations," the researchers said in their report.​

Read more: http://www.cbc.ca/technology/story/2010/12/13/science-salmon-study.html#ixzz181dFxmrr​

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[cuttlefish]

Published online 13 December 2010 | Nature | doi:10.1038/news.2010.669

News
Fish-farm lice acquitted of killing wild fish

Sea lice from ocean pen farms might not be a menace to wild salmon.

Emma Marris
Spawning pink salmon (Oncorhynchus gorbuscha) and chum salmon (Oncorhynchus keta) in a shallow river at Kinak Bay at Katmai National Park, AlaskaWild salmon may be passing on sea lice to farmed salmon — not vice versa.Paul Souders/Corbis

One year, the pinks didn't come home. In 2002, 97% of the pink salmon (Oncorhynchus gorbuscha) that were expected to swim up rivers to spawn in British Columbia's Broughton Archipelago failed to appear. Something had killed them during their two-year sojourn at sea.

Environmentalists suspected that sea lice (Lepeophtheirus salmonis) were responsible — and that the wild salmon had caught the lice from farm-raised Atlantic salmon (Salmo salar) living in mesh pens at sea. For instance, the Seafood Watch project at the Monterrey Bay Aquarium in California, whose 'pocket guides' help health- and eco-conscious consumers shop for fish, tells people to avoid all salmon farmed in ocean net pens, in part because of their role in incubating sea lice.

But a new study published today in Proceedings of the National Academy of Sciences acquits the lice of this charge1. After analysing over a decade's worth of statistics from fish farms, a team led by Gary Marty, a veterinary pathologist at the University of California, Davis, suggests that the farmed fish instead seem to pick up the lice from wild salmon — and, in any case, the lice don't seem to have been responsible for the 2002 population crash.

The pernicious effect of lice from fish farms became a generally accepted fact after studies seemed to connect them to declines in wild salmon populations. In 2007, a study2 led by Martin Krkošek, then at the University of Alberta, Edmonton, showed that the numbers of pink salmon in rivers exposed to farmed fish declined after 2001, when the lice were first noticed. "If outbreaks continue," Krkošek wrote, "then local extinction is certain." Other studies by the same team manipulated louse numbers and duration of exposure on baby pinks in experimental pens. More salmon tended to die if the population was exposed to many lice for an extended time3.
Reversing the link

Marty's team have now looked at existing data on pink salmon populations, along with new data from the fish farmers: annual estimates of sea lice and farm-fish numbers, dating back to 2000. Some of these data were pulled from handwritten logs ferreted out of the archives of farm companies by co-author Sonja Saksida, a fish veterinary surgeon at the British Columbia Centre for Aquatic Health Sciences in Campbell River, who has worked for the farms in the past.

In its modelling of the data, the team found that, year-to-year, high numbers of adult wild pink salmon are a predictor of high numbers of sea lice on farms. Therefore, farmed fish seem to catch the lice from wild populations. But high numbers of sea lice on farms are a predictor of high numbers of lice on juvenile pink salmon. So, as they travel past the farms, the wild babies might be catching the lice earlier than they otherwise would. Crucially, however, louse concentrations on young wild salmon do not predict the fishes' population numbers when they head back to their birth streams.

Although the juveniles that disappeared in the ill-fated 2002 group were exposed to many sea lice, the juveniles from the previous year were exposed to even more lice, and returned to their birth streams in huge numbers.

But what about the studies that showed that lice can kill juvenile fish? Marty and his team point out that pinks can also eat sea lice, so a lousy sea is also a buffet table for the salmon. Increased food may offset louse-related deaths.

Marty suggests that the 2002 crash was due to some unrelated cause, perhaps a virus or bacterium. He admits that it is possible that sea lice were part of a combination of factors that led to the declines; perhaps lice or viral infection alone aren't enough to kill that many fish, but if both occur in the same year, many juveniles die. However, he doesn't think that this is likely.
Lost in variation

Krkošek, now at the University of Otago in Dunedin, New Zealand, is not convinced. He finds the suggestion that farmed fish catch their lice from adult wild fish interesting. But he doesn't buy the idea that louse-related mortality does not affect wild salmon populations. "There are two interpretations," he says. "One is there really is no relationship. The other is that their methods of analysis were too weak to detect it."

Krkošek says that his own analysis controlled for random variation in the pink salmon's environment — factors such as ocean temperature, fluctuation in food supply and predator abundance. "It you don't control for that," he says, "you are just lost in that random variation."

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In response, Marty's co-author, Terrance Quinn, from the Juneau Center at the University of Alaska Fairbanks, says that their model does include "a residual term for other unexplained variability". "The relationship could indeed be there," he adds, "but if it is, it is swamped by other unexplained variation."

Krkošek worries that the new results will set back policies in Canada designed to limit the flow of lice from farms. Meanwhile, Marty suggests that the millions of dollars spent on enclosed tanks for farmed fish might have been wasted.

But Marty cautions that his results can't be extrapolated to the Atlantic Ocean, where sea lice are known to be more dangerous to salmon. Meanwhile, the Monterrey Bay Aquarium is unlikely to revisit its 'avoid' recommendation. The organization's warning is also based on the environmental impact of the food fed to farmed salmon, each one of which requires three times its weight in food — often, wild fish of other species.

*
References
1. Marty, G. D. et al. Proc. Natl Acad. Sci. USA doi:10.1073.pnas.1009573108 (2010).
2. Krkošek, M. et al. Science 318, 1772-1775 (2007).
3. Krkošek, M. et al. Proc. R. Soc. B 276, 2819-2828 (2009)
http://www.nature.com/news/2010/101213/full/news.2010.669.html

 

[cuttlefish]

Link to Journal article abstract;
http://www.pnas.org/content/early/2010/12/03/1009573108.abstract

 

[Lipripper]

Published online 13 December 2010 | Nature | doi:10.1038/news.2010.669

News
Fish-farm lice acquitted of killing wild fish

Sea lice from ocean pen farms might not be a menace to wild salmon.

Emma Marris
.........................
But Marty cautions that his results can't be extrapolated to the Atlantic Ocean, where sea lice are known to be more dangerous to salmon.

Then are they weaker fish or stronger lice on the other side?

Kinda funny that the lice are less harmful over here.

 

[Mi Chica]

Amazing. Lice harmful (read high mortality) in Atlantic but not in the Pacific. Bull!! It is the same species, there are well documented numbers showing very high lice numbers (year round) where they have net pens operating. Further, we have the history of this type of operation in other parts of the world. The depletion and extinction of once vibrant wild fish stocks elsewhere in the world where net pens have been located has been well documented. It has happened far too often to be accepted as coincidence by any rational being. Enough crap, closed containment or shut down are the only viable options if we wish to have wild stocks left. Period.

 

[Little Hawk]

Before we all go and start a 'group-hug' with the salmon farmers over this latest drivel from a dieing industry, take a second to read about (from Rafe Mair) who funded the study: ...
the provincial Ministry of Agriculture, and Lands, formerly Agriculture, Food and Fisheries, the former long time home of John "Three Fish" Van Dongen, The Federal Department of Fisheries and Oceans (DFO) which is now under close examination by the Cohen Commission and, are you ready for this? Aboriginal Aquaculture Association, Aquaculture Association of Canada, Canadian Aquaculture Industry Alliance, BC Salmon Farmers Association, BC Shellfish Growers Association, Sustainable Seafood Innovation Partnership, Northern Aquaculture Magazine

In addition, one of the researchers does regular contract work for the Fish Farmers

 

[Charlie]

I would have to second that!

“The findings of the study headed by Gary Marty, a professor at the University of California…” ???
“The study's lead author is Gary Marty, a veterinary pathologist and research associate at the UC Davis School of Veterinary Medicine.” ???

I think, what they really meant to say is, Gary Marty is an “Associate (WITH OUT SALARY) at the University of California Davis School of Veterinary Medicine. He works and gets paid by B.C. Ministry of Agriculture and Lands. And he indeed, DOES have a background and history consulting for aquaculture in the U.S..

E-mail: gdmarty@ucdavis.edu
Title RESEARCH ASSOCIATE(W/O SALARY)
Department VM: ANAT PHYSIO & CELL BIOLOGY

Gary Marty, D.V.M., Ph.D., Diplomate, A.C.V.P.
Research Associate
Email: gdmarty@ucdavis.edu
Department of Anatomy, Physiology and Cell Biology
1321 Haring Hall
School of Veterinary Medicine
University of California
Davis, CA 95616
Phone: (530) 752-1174
Fax: (530) 752-7690

Where does he really work?
Animal Health Centre
B.C. Ministry of Agriculture and Lands.
1767 Angus Campbell Road
Abbotsford, British Columbia
V3G 2M3
contact: Dr. G. Marty
phone 604-550-3003
fax 604-556-3010
e-mail: Gary Marty@gov.bc.ca
http://www.agf.gov.bc.ca/ahc/ahcfishlab.htm

He may have forgotten, he made this statement:
44. On the issue of the quality and availability of data, I note the evidence from the Province that it did not regulate the aquaculture industry until 2001, and that documents from prior to 2000 have been destroyed. In her affidavit, Ms. Sidhu deposed that she had been advised by Gary D. Marty, D.V.M., Ph.D., Diplomate, A.C.V.P. Fish Pathologist that:
1. ....:
(a) The Cases from 2000-2002 - … These records are stored electronically in an archived database. … We would be able to provide individual case reports, but these case reports would not be summarized on a spreadsheet …
(b) Note that many of these case reports will have no information about the farm of origin. …
(c) Cases before 2000 – we have no records from cases before 2000 (they have all been destroyed).
http://www.cohencommission.ca/en/pdf/Rule19Application.pdf#zoom=100

Concerning that study, article, or what-ever you want to call it? Let’s see if I have this right? He works for the government of BC, who did NOT publish this? You take everyone tied within the “aquaculture business,” hire an individual (known to a friendly past consultant for the aquaculture industry in the U.S.), to prepare a study. That individual has just recently advised the Cohen Commission and stated "the information does NOT exist". Then less than a month states the aquaculture industry (fish farms) suddenly provided the information (that THEY want him to have). Then have an article published by “Davis,” in California - not by BC (for which he works and it is not peer revieved) then state the results are “proof” and “non-biased”? Yep, with enough money and deception, I will convince you the moon is made of “Green Cheese”! I do NOT believe this "article" carries, or has any merit - at all, and there do seem be a “few” that might just disagree? Some that tend to believe that non peer reviewed "article," might want to read a tad bit closer and paying close attention to who prepared it and who paid for it?

Then might want to read this:
Synthesis of Evidence from a Workshop on the
Decline of Fraser River Sockeye
June 15-17, 2010
Vancouver Island Conference Centre
Nanaimo, British Columbia

Prepared by:
Randall M. Peterman, Simon Fraser University (Chair), David Marmorek, ESSA Technologies Ltd., and (in alphabetical order); Brian Beckman, U.S. National Marine Fisheries Service, Michael Bradford, Fisheries and Oceans Canada, Michael Lapointe, Pacific Salmon Commission, Nate Mantua, University of Washington, Brian Riddell, Pacific Salmon Foundation, Mark Scheuerell, U.S. National Marine Fisheries Service, Michael Staley, IAS Ltd., Katherine Wieckowski, ESSA Technologies Ltd., Jim Winton, U.S. Geological Survey, Chris Wood, Fisheries and Oceans Canada

Prepared for:
Pacific Salmon Commission, Vancouver, British Columbia
31 August 2010

http://www.psc.org/pubs/FraserSockeyeDeclineWorkshopReport.pdf

 

[Cuba Libre]

Good Job Charlie

 

[sockeyefry2]

Don't forget Charlie there are biological prostitutes on both sides. This one you happen to not agree withwhat he says.

I don't know about pac salmon not being affected, but I do know that fewer lice on the atlantic coast cause much more damage than what I have seen on the Pacific side. Maybe they aren't exactly the same species

 

[Charlie]

Don't forget Charlie there are biological prostitutes on both sides. This one you happen to not agree with what he says.

I don't know about pac salmon not being affected, but I do know that fewer lice on the atlantic coast cause much more damage than what I have seen on the Pacific side. Maybe they aren't exactly the same species

J You are absolutely correct! That is why people need to really read those studies, reports, and in this case “paper”!

“He said he has never worked for any fish farm company in Canada; in the United States, he consulted for the industry in 2000 and 2001. Since 2004, he has analyzed fish-farm samples for the British Columbia provincial government.”
http://www.seafoodsource.com/newsarticledetail.aspx?id=8734&src=rss

The ”paper” written by the three is here:
http://faculty.vetmed.ucdavis.edu/faculty/gdmarty/2010PNAS-Marty-etalSeaLicePaper.pdf

Please note the “Conflict of interest statement”:
“Author contributions: G.D.M. designed research; G.D.M. and S.M.S. performed research; G.D.M. and T.J.Q. analyzed data; and G.D.M., S.M.S., and T.J.Q. wrote the paper. Conflict of interest statement: None of the authors received compensation from any source for this analysis. S.M.S., as part of her private veterinary practice over the past 15 y, has done contract work for all three fish farm companies that operate in the study area (these companies are cited in the acknowledgments, and this relationship was vital for obtaining all proprietary farm medical records for this study); S.M.S.’s spouse started working for closed-containment aquaculture operation in September 2010.”

So not just ONE, but all THREE of those individuals, who wrote this particular “paper?”, have ties with “FISH FARMS”!

And then just to add... Read the paper! If you really read this "paper," and that is why it is probably called a "paper," and not a study, it doen't really confirm anything - good or bad, just opinons!