Research
Farmed salmon could be contaminated with synthetic flame retardants called polybrominated diphenyl ethers (PBDEs) if their feed is sourced from regions with little or no environmental regulations, suggests a new study, but is it a reason to avoid farmed salmon altogether?

A University of Pittsburgh study led by Dr Carla Ng, assistant professor of civil and environmental engineering at the Swanson School of Engineering, tracked the presence of PBDEs in farmed salmon.

Despite having been banned in the United States and much of Europe in 2004 because of environmental and public health concerns, PBDEs continue to be released into the environment from products manufactured before the ban of PBDEs, the study says.

“They enter the air and water and can accumulate in prey fish which are then used in the manufacture of feed ingredients,” Ng explains to Aquaculture North America (ANA).

If the exact location of the catch used as feed ingredients is unknown and/or the materials have not been tested for the presence of the pollutants, it can be difficult to tell ahead of time which animal-derived feed ingredients contain PBDEs, Ng acknowledges. But the study noted that PBDEs are particularly dense in areas such as China, Thailand, and Vietnam, countries that process a lot of electronic waste and lack rigorous regulation of their recycling industries.

Dr Neil Auchterlonie, Technical Director at IFFO, the marine ingredients organization, recognized the presence of these chemicals in “extremely small (amounts) and in generally declining concentrations.”

In deciding whether this means we should stop eating farmed salmon, Auchterlonie tells ANA: “One of the facets of the continual development of analytical technology is the identification of some of these compounds in ever-smaller concentrations. Those results are often so small that they are confusing when it comes to the interpretation of risk. That risk is important to bear in mind when taken into account with the noted benefits of consuming seafood.”

He adds that it is also important to recognize that these materials are found throughout the environment, not just in seafood. In fact, synthetic flame-retardants are everywhere. “As well as being present in the aquatic environment, PBDEs are present in the atmosphere, and in dust, which can also be sources of exposure,” he says.

Still, the risk to human health appears to be minute. A report from the Norwegian Scientific Committee for Food Safety, which covered an extensive overview of contaminants including PBDEs, concluded that the risk of adverse health effects due to PBDEs is low.

Animal nutrition specialists and fish feed manufacturers contacted for comment did not respond by our deadline.



A research project that explores the use of kelp perch and pile perch as means to control sea lice infestations in farmed Atlantic salmon in British Columbia has received additional funding from Sea Pact.
YouTube videos come in handy for professional development or for anyone simply interested about learning more about fish farming.

You want this person to listen to you. But you know that if he would, he might only give you very short time and, even then, there are other people lining up to talk to him as well.
This could very well be the same case whenever you upload an extension video on sharing sites such as YouTube.

So how do you seize the moment?

“Make sure that you have a quality opening and get into the meat of the material quickly,” Dr David Cline, an extension aquaculturist at Auburn University in Alabama, told Aquaculture North America (ANA).
Cline is behind Aquaculture Education and More channel on YouTube, which he started in 2013. His most popular video is on in-pond raceways, which has been viewed 120,000 times. Educational videos on YouTube have an average of 4,872 views.

“A good opening sequence is okay as long as it is visually compelling and high quality,” he continued.  “Use good visuals early.” Interesting photos, an interview, good graphics always help.
Thirty seconds is all it takes for viewers to decide if a video suits their needs. And even less if there are other videos available online on the topic. “I have seen topics that in some videos are covered in one minute and the same topic in another takes five minutes or more.  Which would you rather watch?,” he asked.

Pace is another important element. “Don’t stay on the same picture or  scene for more than 10 to 15 seconds,” he said.  “Try to think like a director. The next time you watch a TV show start counting each time the shot changes. You will be surprised how few times you get to 10.”

On top of the education component, the video must also be entertaining.  Otherwise, viewers would most likely move on to something else.  “A video is sort of an exchange. I give you my time to watch the video and I want something in return,” he said. “If the content is not what I want or is boring I feel like the video has stolen my time from me.”

Selecting topics depend on your passion, a topic you are currently working on, or a story that you want to tell. It could also be about a question you have been asked several times before or just simply taking advantage of an opportunity. Examples, he says, are the harvest of a big pond, or a feeding frenzy.  “It something that is interesting but is not necessarily a full-blown idea or story.”
Efforts to combat sea lice infestations through natural means have advanced with the first spawning of farmed ballan wrasse in captivity.

Wild ballan wrasse has been used in salmon farms in Scotland for years as a non-chemical way of controlling sea lice infestations, but reliance on wild catch is unsustainable.

The milestone in the culture of the so-called “cleaner fish” has been reached at a hatchery in Machrihanish, Scotland, which is a joint venture between Marine Harvest and Scottish Sea Farms.

Although the wrasse produced at the hatchery will go to the companies’ salmon farms, the industry will benefit from the research. “The research we have done here is for everybody. We have close links with Norway and other hatcheries in Scotland and the information can be disseminated all around the industry. It is a joint industry project and we welcome the opportunity, if need be, to supply larvae to hatcheries,” says hatchery manager Paul Featherstone.

There are plans to expand the existing facility over the next few years, and the expansion could enable the hatchery to produce 1.5 to 2 million wrasse annually, says Featherstone.

“This is a total win-win situation,” says John Rea, director of Scottish Sea Farms, in a film about the role of wrasse in salmon aquaculture. “Our fish are better off by having this partner in their nets alongside them. It means we have a much lower environmental footprint than we’d otherwise have; the medicine bill is reduced. It makes salmon more suitable.”



Researcher suggests noise pollution could affect reproductive behavior and stress levels of fish
Massachusetts-based biotech company KnipBio has been awarded a grant to study how changes in diet can alleviate enteritis and other diseases in aquaculture.

The company is known for its fishmeal ingredient called KnipBio Meal (KBM), which is derived from microbes instead of wild-caught fish or agricultural crops.

Enteritis is a common diet-related disease in farm-raised carnivorous fish that can lead to slower growth and increased mortality. It is estimated this disease costs the aquaculture industry more than $1 billion per year.

Preliminary feed trials have consistently found that fish and shrimp fed KnipBio Meal experience improved gut health, lower rates of enteritis, and reduced mortality levels compared to populations raised on standard industry diets. The goal of the grant is to study the mechanism by which KBM acts as a prebiotic to affect gut health of rainbow trout and identify the specific components in KnipBio Meal responsible for this effect. It will be conducted over the course of one year and, if successful, may lead to additional funding to commercialize the findings.

The grant was from Phase I Small Business Innovation Research (SBIR) grant by the National Science Foundation.
Do wild salmon interact with farmed salmon? If so, how often?  These are just some of the questions that a new project hopes to answer to determine why wild salmon populations are declining.

The $500,000 study launched by New Brunswick’s Department of Fisheries and Oceans is in cooperation with the aquaculture industry. It involves establishing 24 receiver sites on Passamaquoddy Bay and the river system. Sixty young salmon were tagged in the river system and then released. Those tags trip a sensor in the receivers when the fish swim within range. That information will inform scientists whether wild salmon are in fact interacting with farmed salmon in open-net pens and how often.

“There are concerns about the potential transfer of disease from wild salmon to aquaculture, but also the potential for transfer of disease from aquaculture to wild salmon,” DFO researcher Marc Trudel told Global News.

With this being a pilot project, it’s not known how long it will take to gather the needed information, or how that data may shape future policies, Trudel added.
First wine, now whisky.

A startup that’s developing aquaculture feed made with byproducts from the whisky distilling process has attracted roughly $671,600 (£500,000) in investment.

The company, MiAlgae, uses by-products from the distilling process to grow Omega 3-rich algae for feeding farmed salmon.

 Douglas Martin founded the company while a masters student at the University of Edinburgh in 2015-16. He said he wanted to revolutionize the animal and fish feed industries with microalgae that come from whisky.

The investment, in equal shares from Equity Gap, the Scottish Investment Bank, the investment arm of Scotland’s enterprise agencies, and the University’s venture fund Old College Capital, will enable the company to expand its team and build a pilot plant for its technology at a whisky distillery.

"This investment will fund the initial scale-up steps and de-risk our commercial facility. It certainly sets us on track to achieve our ambitions," Martin said.

Earlier, in Australia, an aquaculture feed made with grape marc – skins, pulp, seeds, and stems left over after wine is made – has shown promising results in lab trials.
Both produce similar levels of off-flavor in catfish, study shows
Marine Harvest has applied for development licenses to test semi-closed technology concepts as it continues to seek new and innovative solutions for the aquaculture industry.
A new study on the effects of Piscine Reovirus (PRV) on wild salmon has met with criticism from experts.
Findings of three-year on-farm demonstration study entice Eastern seaboard oyster farms to begin adapting flip-bag technology


Oyster aquaculture in the United States has rapidly expanded in the past 20 years, and oyster cup shape, as well as taste, is critical to the consumer. Deeper cups are preferred because they suggest a higher volume of meat.

Cup shape can be manipulated through handling practices – the more an oyster is handled, the more new linear shell growth gets broken off, leading to the formation of a deeper cup. Some oyster farmers use a method of breaking off new growth by placing oysters in a “tumbling” device once in a while. A more convenient alternative is the relatively new “flip-bag” system, a conventional plastic mesh bag designed to rotate with the rise and fall of the tide, tumbling the oysters automatically.

While the flip bag method has been a big success on the West Coast, it has yet to make a big impact with growers on the East Coast. A small research project at Rogers Williams University in Rhode Island a few years ago showed that flip bags resulted in oysters of excellent quality, so the technology was further studied in a research project from 2014 to 2017 as part of a bigger plan to develop a Northeast Aquaculture Research Farm Network (NARF-Net) through on-farm demonstration projects. The use of NARF-Net “provided an excellent opportunity to evaluate the efficacy of using tide-tumbled flip bags to produce superior grade oysters on New England farms,” states the final study report, released in July 2017.

The study evaluated three styles of flip bags (Seapa, BST and ADPI bags) in terms of the grade and meat quality of the eastern oyster (Crassostrea virginica) compared to traditional rack and bag and floating culture systems.

The research team found that the flip bag system produces an oyster with higher meat content than a conventionally farmed oyster. “The application of flip bag culture yields a slower-growing but higher grade oyster, compared to traditional culture methods, with a large volume of edible tissue, which may lend itself to a higher market value,” states the final report. It cautions, however, that “careful consideration of site selection and space utilization is critical in successful application of the flip bag system.”

As of July 2017, the researchers were aware of two East Coast oyster farms (that had participated in the study) using the flip-bag system “with numerous more farms considering it.”

The study also included evaluation of artificial media to grow quahogs. The research team found preliminary evaluations “promising from a technical standpoint, where clam growth and survival was equivalent between quahogs held in oyster bags versus those reared infaunally in native substrate. However, the team said the lack of a suitable artificial substrate in terms of handling weight “precludes the use of this technology in its current form on commercial farms.”





A Baltimore, Maryland startup has come up with a novel way of battling Viral Nervous Necrosis (VNN), a disease that affects over 40 aquaculture species worldwide.

Dr Ken Malone, CEO of startup VakSea Inc, says the aquaculture industry’s big problem has not been the absence of effective vaccine, rather, it is in the way those vaccines are delivered.

“Current methods of delivering vaccines to fish involves injecting fish with vaccine one by one, which is expensive, labor intensive, and stressful to the fish,” says Malone.

VakSea grows the vaccine inside insect larvae, grinds up the larvae, mixes it into fish feed, then feeds it directly to the fish. When the fish eats the feed, they become immune to the disease.

The startup’s proprietary vaccine technology was developed at the University of Maryland Baltimore County in the lab of Dr Vik Vakharia beginning in 2014. VakSea filed a provisional patent application in 2016. It is now developing a pellet-based vaccine aimed at protecting European seabass juveniles from VNN and hopes to get it to market over the next 12 to 18 months.

VNN “damages the central nervous system in susceptible fish species and typically affect younger stages of fish (larvae, fry, fingerlings), although older, market-size fish can be affected as well, with losses ranging from 15–100 percent,” according to University of Florida-IFAS Extension researcher Roy P. E. Yanong, in his paper Viral Nervous Necrosis (Betanodavirus) Infections in Fish.

“Infected larvae and juvenile stages often show abnormal swimming behaviour, including vertical positioning and spinning; flexing of the body,” he wrote.

Species susceptible to VNN include red drum, cobia, sea bass, barramundi, gilthead seabream, Pacific bluefin tuna, various grouper species, various flatfish species including halibut and Japanese flounder, and tilapia.

Malone is confident of the potential of VakSea’s proprietary vaccine technology in other species. “We’ve proven it out on the nervous necrosis virus and we know it’s going to work on a large number of species and a large number of other diseases,” he says.



There’s plenty of environmentally suitable areas around the world for marine aquaculture but factors other than space availability could limit its development, a study suggests.

The study, Global estimation of areas with suitable environmental conditions for mariculture species, defined “suitable areas” as those that can support the physiological needs of farmed species for sustainable mariculture production.

The study estimates that 72,000,000 km2 of ocean would be environmentally suitable to farm one or more species. About 92 percent of the predicted area or 66,000,000 km2 is environmentally suitable for farming finfish, 43 percent or 31,000,000 km2 for molluscs and 54 percent or 39,000,000 km2 for crustaceans.

The University of British Columbia study team, led by Muhammed A. Oyinlola, suggests that suitable mariculture areas along the Atlantic coast of South America and West Africa appear to be most under-utilized for farming.

“Our results suggest that factors other than environmental considerations are currently limiting the potential for mariculture expansion in many areas,” says the study.

The limiting factors include: the socio-economics of producing countries, including capacity and political instability; technology, its availability and cost effectiveness; trades; aqua feed availability; aquaculture development-related policies and competition for space within countries’ exclusive economic zones (EEZs), for instance — shipping, oil and gas, as well as tourism — all play major roles in the development of mariculture operations and their future expansion.

The results reflect those of an earlier study, Mapping the global potential for marine aquaculture, conducted by UC Santa Barbara researcher Rebecca Gentry, et al.

After 10 years of research Nofima scientists have finally “cracked the code” to produce sterile farmed salmon.

 Inducing sterility in farmed salmon will make them unable to interact genetically with wild salmon populations.

"In practice we don’t touch the genes, but affect a protein that is necessary to enable the fish to produce gametes,” said senior researcher Helge Tveiten.

They have not seen any indications that the fish will become sexually mature or develop the urge to migrate in order to spawn.

Paving the way for the research was a previous study carried out on zebra fish, which identified a few genes that are decisive in the development of gametes.

“The salmon we have researched do not develop gametes, and will never be sexually mature,” Tveiten added. “We see a tiny egg sac in the female fish, but no eggs are formed. The male fish develops what appears to be normal sexual organs, but they don’t have sperm cells.”

Tveiten’s work is part of the SalmoSterile research project financed by the Research Council of Norway. The project is a collaboration between the Norwegian Institute of Marine Research (NIMR) and several major industrial companies, including AquaGen.

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