Tag Archives: research

“Yellow fish” issue in farmed Chinook salmon not linked to PRV, new study shows

Three heavy hitters in BC’s fisheries and aquaculture science community have published a new study after a laboratory challenge of several different species of salmon.

The study investigated the phenomenon of yellow (jaundiced) fish from a Chinook farming operation in Clayoquot Sound; the level of Piscene Reovirus (PRV) in these fish compared to other species; and any disease associated with jaundiced fish and PRV infection.

 

Activists have made much of finding yellow salmon but research shows there's no connection with PRV or a disease only observed in Europe.
Activists have made much of finding yellow salmon but research shows there’s no connection with PRV or a disease only observed in Europe.

In our controlled laboratory exposure study, we demonstrated that PRV persisted in each of the Chinook Salmon, Sockeye Salmon and Atlantic Salmon for 5 months after ip challenge without resulting in microscopic evidence of HSMI or any other disease.

Our study supports the hypothesis that exposure to PRV is not solely responsible for the development of Jaundice Syndrome. It may be possible that the presence of PRV is not contributory towards jaundice in Chinook but rather that its association is merely a reflection of the ubiquitous presence of PRV in wild and farmed salmon species of BC.

The research supports the conclusion that in Pacific waters, PRV is not connected to the Heart and Skeletal Muscular Inflammation (HSMI) disease, and that there is no connection between PRV and the jaundice phenomenon in farmed Chinook salmon.

 

Recycling your old iPhones… with salmon semen

This story was too weird to pass up:

“Japanese scientists have discovered that salmon semen from industrial fish farms could help to recycle rare earth metals.

Researchers led by Yoshio Takahashi from the University of Tokyo, found that salmon semen, known as milt, can be used in a process to extract certain rare earth elements that are used in products such as catalysts, alloys, magnets, optics, lasers and notably mobile phones.”

Only from Japan: salmon semen can help recycle electronics. Apparently.
Only from Japan: salmon semen can help recycle electronics. Apparently.

Apparently the semen, known as milt, “has the capacity to bind to positively charged ion material” making it a potential replacement for many caustic and dangerous chemicals currently used in the electronics recycling process.

The craziest part about this story is that there is a huge source of material available.

According to the paper, “More than 10,000 tonnes per year of milt from salmon, trout and others have been discarded as industrial wastes from fishery industries in Hokkaido, Japan.”

Again that’s

10,000 TONNES OF SALMON SEMEN.

BC salmon farms only raise about 70,000 tonnes of fish per year. There’s no way that there’s that much milt being used, let alone discarded, in BC. Japan doesn’t farm salmon on any significant scale, certainly not enough to produce that much milt.

This milt must be leftover from Japan’s massive “salmon ranching” aquaculture enhancement projects, which release more than 1 billion Pacific salmon from Hokkaido Island (referred to in this study) each year.

Aquaculture antibiotics study needs more context

A new study about antibiotics in aquaculture was recently published in the Journal of Hazardous Materials, and although it provides some good, useful data, it doesn’t mean much without more information.

Study highlights

  • 5 out of 47 antibiotics were detected in shrimp, salmon, tilapia and trout.
  • Oxytetracycline is the most commonly detected antibiotic compound.
  • Antibiotic resistant bacteria in seafood increase >8-fold in the last 3 decades.
  • We report a low risk of drug exposure from consumption of U.S. seafoods.
  • We recommend vigilance toward stemming microbial risks.

Sounds pretty innocuous, but as usual, the data is already being used by third parties to suggest that antibiotic usage in seafood farming is high and a potential problem.

Not true.

Let’s clarify one thing. Seafood farming and aquaculture have different meanings. Aquaculture is a far more general term, which includes farming as well as enhancement projects.

Wild salmon DO do drugs

Let’s use the definition supplied by the American Fisheries Society.

Aquaculture is an established and growing industry in the U.S., and an increasingly important supplier of foods for U.S. consumers.

The industry also produces baitfish for sport-fishing and ornamental fish for the pet trade.

In addition, federal and state fish hatcheries raise millions of fish for stocking in U.S. waters to support commercial and recreational fisheries and species restoration efforts.

Aquaculture is an important contributor to U.S. agriculture and a cornerstone of aquatic natural resources management.

All aquaculture operations will have a demand for drugs, biologics, and other chemicals, collectively referred to as “regulated products”.

There you have it: wild salmon DO do drugs!

Unfortunately, while this new study looked at five common species, including farmed American catfish, it did not look at any aquaculture-raised American salmonids. This is a glaring oversight, considering that billions of them are raised in aquaculture facilities and released every year on the Pacific coast.

It would be very interesting to see what sort of amounts of antibiotics are used in Pacific salmonid enhancement facilities in Canada and the USA.

Antibiotic resistance predates antibiotics!

Research published in 2011 adds even more interesting context to this study.

It suggests that making judgements about antibiotic resistance in aquaculture may be difficult: DNA from 30,000 year old microbes recovered from permafrost show antibiotic resistant traits similar to their modern counterparts.

Related stories

Antibiotics in aquaculture: getting the facts straight

Alexandra Morton’s furunculosis fable

What’s better than debunking Morton myths? Seeing a real salmon scientist get international recognition!

We were going to write about the contradictions, lies and half-truths which characterized activist Alexandra Morton’s hour-long radio love-in with Ian Jessop on CFAX yesterday.

But we didn’t really want to.

The official seal of the Pseudoscience Labelling Initiative, which may soon be required by law to preface any publication by Alexandra Morton.
The official seal of the Pseudoscience Labelling Initiative, which may soon be required by law to preface any publication by Alexandra Morton.

It’s just too painful to debunk the same points over and over again. We’ve already addressed them many times on this blog, particularly her claim that the ISA virus is in BC (even though she contradicted herself on the show by admitting her results were not confirmed).

We’ve also talked about another point she raised about Piscine Reovirus, which recent research shows has been in wild fish since at least the late 1970s. This physical evidence, of course, makes her claims based on computer modelling that it must have been introduced by salmon farms in the mid-2000s moot.

A great scientist’s career recognized

So we were thrilled to read today that one BC scientist, who has been a cornerstone of fisheries science and who has published hundreds of papers crucial to understanding wild salmon, was recognized by the prestigious International Council for Exploration of the Seas.

Carl Walters
Dr. Carl Walters

Yesterday, UBC’s Dr. Carl Walters was awarded ICES’ Prix D’Excellence, an award recognizing scientists who “have contributed to the sustained use and conservation of marine ecosystems through their research, scientific leadership and/or leadership in the objective application of science to policy. Innovation, teamwork, mentoring, and objective communication with the public exemplify the career of the recipient of this award.”

Congratulations to Carl on this well-deserved award! His work over the past decade has been crucial in helping us better understand wild salmon dynamics, as well as interactions between wild and farmed salmon.

As the press release from ICES states:

“Over his career, Dr. Walters has been the most innovative scientist working in marine ecosystems and fisheries management,” remarked ICES Awards Committee Chair Pierre Petitgas at the awards ceremony during the ASC opening session. “He has also been a well-known advocate for co-operation between scientists and fishermen and has promoted cooperative arrangements between governments and fishing industries to provide improved information for stock assessment and management via methods such as industry-based surveys.”

Here is the full press release from ICES.

 

Why does farmed salmon flesh sometimes go soft? Study offers new insights

Kudoa in Atlantic salmon fillet
Soft and separated flesh in a salmon fillet caused by Kudoa

When customers open a box of fresh, farmed salmon only to find the flesh has gone soft after being in storage for a few days, that’s a huge problem for both the customer and the seller.  No one wants that to happen.

Most of the fish produced in BC is premium quality.  But sometimes soft flesh problems arise.

BC salmon farmers have worked for years to prevent this from happening — after all, premium quality fish command premium quality prices.

Years of research have pinpointed one common culprit behind soft flesh: a fish parasite known as kudoa, which sometimes affects BC farmed salmon but has also affected wild-caught BC fish used in fish sticks and surimi for 40 years.

But sometimes soft flesh in farmed salmon happens without the presence of kudoa, and a 2014 study brings us closer to understanding why.

The study’s findings suggest that soft flesh is linked to how much glycogen (stored sugar) the fish has in its cells:

“We report for the first time an association between soft flesh of Atlantic salmon and massive intracellular glycogen accumulation coinciding with swollen and degenerated mitochondria, myocyte detachment and altered extracellular matrix protein distribution. The results are important for further understanding the etiology of soft salmon.”

The study authors caution that they are not sure if the accumulation of glycogen is a symptom or cause of soft flesh, but the new findings will definitely help researchers better understand what is happening with soft salmon flesh and get closer to finding a solution.

Risk assessment of Norwegian salmon farming offers some surprising points

Every year since 2011, the Norwegian Institute of Marine Research has published a risk assessment for ocean salmon farming in Norway.

The results, most recently published in July 2014, offer up some points that might surprise die-hard salmon farming critics.

The most concerning risks in Norway, according to the research, are:

  • Wild Atlantic salmon face a moderate to high risk for “genetic introgression” (cross-breeding) from escaped farmed Atlantic salmon.
  • About 27 of 109 farms investigated for sea lice infection indicate moderate to high risk of likelihood for passing wild salmon smolts, and 67 farms indicated moderate to high risk of mortality from sea lice for wild sea trout.

The interesting results are in what doesn’t appear to be a concern:

Despite “extensive release of virus in many areas,” screening of wild salmonids showed low to very low presence of the same viruses.

  • Only 2% of all farms displayed unacceptable levels of “organic loading” (fish poop and feed) below the farms; therefore the “risk of eutrophication and organic load beyond the production area of the farm is considered low.
  • It’s interesting that, in Norway at least, the two points that salmon farm critics seize on the most — viruses and fish poop — are of least concern.

It’s debatable how meaningful it would be to extrapolate these findings to BC, but they raise some interesting points. Here in BC, where we have strong populations of wild salmon, which are unable to interbreed with farmed Atlantic salmon, the issue of “genetic introgression” is moot.

More than a decade of sea lice research has also shown that sea lice from salmon farms are unlikely to have any measurable impact on wild salmon, as experts at the Cohen Commission agreed.

Also, as BC experts said, the risk to wild salmon from farm diseases might be possible, but is also probably low.

Lazy reporting, mean girls and plankton blooms

Linda Aylesworth of Global News took activist Alexandra Morton’s bait and ran a segment on TV about her recent attack on Grieg Seafood.

Unfortunately, Aylesworth didn’t make any effort to fact-check the claims of either Morton or the Grieg Seafood managing director quoted in the story.

“It’s a classic ‘he said, she said’ story,” Aylesworth states in the segment.

That’s a cheap cop-out and reinforces the cliche of the big company hiding something while the lone, plucky activist tries to uncover the truth. It’s also a lazy out for journalists who claim they are just presenting “both sides of the story” and letting viewers “make up their own minds.”

Ah, Lois Lane and classic investigative journalism, we miss you.
Ah, Lois Lane and classic investigative journalism, we miss you.

We don’t think that’s good enough, when a topic is being presented in a way that implies one party is lying, and that our precious wild salmon are threatened. The journalist needs to do better.

Why didn’t Aylesworth contact a real ocean biologist, say, someone at UBC or SFU, to ask for more information about plankton blooms so she can actually educate, instead of titillate, her viewers? Why didn’t she contact DFO, which regulates salmon farms, for information about the mass mortality incident, to fact-check the claims made by both interviewees? Why didn’t she contact CFIA, which regulates farmed animal health, and must be informed if any diseases of concern are found in a salmon farm?

No, what we got here is more of the same tired narrative Morton has been promoting for decades and Global TV thoughtlessly regurgitated it without question, and without any attempt to scratch the surface.

 Mean girl rabble-rousing

Some interesting information has trickled back to us about Morton’s activities while filming this farm in Nootka Sound.

Apparently, she and her three friends riled up the tourists who were there to fish, inspiring many of them to boat out to the farm and abuse the farmers over the VHF radio.

Afterwards, Morton got on the radio and tried to play “good cop” by telling the farmers that she’s got nothing against them, that they are just doing their jobs. As she wrote on her blog, “Thank you to the patience of the salmon farming crew at Concepcion Point. This must have been as stressful on you as it was on us.”

How thoughtful. She works to rile up the tourists against them, starts rumours in the media that imply they are thoughtless stooges killing wild salmon and hiding disease, and then she tries to play nice.

Like  the popular girl in high school spreading rumours about you, then pretending to be nice to you the next day.

All about plankton blooms

Plankton blooms are natural in BC and a common occurrence at salmon farms. A few years ago, this blog, which sadly now appears to be defunct, did an excellent post on the topic. It’s well worth a read.

As well, the Harmful Algae Monitoring Project is a great resource. Scientists have been working with salmon farmers since 1999 to monitor and better understand harmful algae (plankton) blooms.