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Our Revolutionary Approach to Feeding Farmed Salmon

A picture of Scott E. Nichols

By Scott E. Nichols

September 13, 2012

Our Revolutionary Approach to Feeding Farmed Salmon

Verlasso was founded with the goal of farming salmon in a way that provides us salmon in perpetuity.  A shorthand I frequently use is, “Salmon in Seven Generations,” to refer to how we need to farm to guarantee salmon beyond the near future.  One of the most important questions is how we feed salmon without adverse effects on other fish populations.

On Salmon Nutrition

All salmon get their essential omega-3s from their diets.  In the wild, salmon eat small oily fish such as herring, anchovies and sardines that are high in omega-3 oils.  Farmed salmon are fed a diet that contains fish oil rendered from these fish. 

The problem is that it takes about four pounds of captured wild feeder fish to provide the fish oil required to raise one pound of salmon.  A shorthand for this is to say the fish in/fish out ratio for fish oil in raising salmon is about 4:1.  This means that for every ton of increase in our worldwide production of salmon, we need to increase our capture of feeder fish by four tons. Can this happen?

In short, no. The Food and Agriculture Organization of the United Nations finds that the world’s feeder fish are harvested at the limits of their sustainability. Feeder fish are a crucial part of the ocean food chain.  Removing more of them would have bad effects on the fish and birds that eat them and on the ecosystem in general.  As a result, the world’s supply of fish oil cannot increase meaningfully. 

Some salmon farmers reduce the fish oil and hence, the amount of omega-3s in salmon diets.  This reduces the pressure on feeder fish, but also lowers the nutritional quality of salmon diets as well as the healthfulness of salmon as food for us. 

Verlasso has found a solution that retains omega-3 levels in salmon diets while simultaneously reducing the dependence on wild feeder fish by 75%. To put this in perspective, 24 million pounds of feeder fish could be left in the ocean if the population of New York City were to enjoy a 6oz portion of Verlasso salmon as a meal instead of traditionally farmed salmon.  This is a revolutionary step in solving the fish in/fish out conundrum for salmon aquaculture and moves us far closer to the goal of having plentiful salmon now and into the future.

The Verlasso Solution-What is it and how is it done?

In the ocean, algae produce omega-3s. The algae are consumed by small animals, which are then consumed by small fish. In this way, the omega-3s make their way up the food chain all the way to the feeder fish on which the salmon feed. 

We have taken the genetic omega-3-producing capability of the algae and transferred it to yeast. This process is a genetic modification and we call the yeast a genetically modified microbe.  The process for growing the yeast microbes is a lot like the process of brewing beer. Our yeast is grown in stainless steel tanks and is fermented to produce a mixture rich in omega-3-abundant yeast. By growing them in these tanks, our yeast are grown in closed-containment systems and do not interact with the environment.

The result is that our yeast makes the omega-3s exactly as the algae do. To make the feed for our salmon, we then mix other ingredients such as proteins, oils and vitamins with the yeast; the yeast is less than 10% of the diet. With this menu, we ensure that the salmon continue to get the omega-3 oils that are crucial for them (and good for us).  At the same time, we are dramatically reducing our dependency on catching wild feeder fish. 

Ensuring Environmental Safety

After the yeast are grown in the closed-containment fermentation process, they are killed at the site where they are fermented so they never have the chance to interact with the environment.  We believe it is important that non-native organisms like genetically modified microbes are not released into the environment as part of this process.

To ensure that they aren’t, they receive three separate heat treatments and each is at a temperature higher than they can survive. One last thing: our yeast won’t grow without being fed vitamin B1, which it cannot get from the natural environment.

As we planned our new approach to salmon farming, we sought feedback from NGOs including Pew Charitable Trusts, World Wildlife Fund (WWF), the Environmental Defense Fund, Physicians for Social Responsibility, and others. Their recommendations were incorporated into our practices, not only for feeding, but also for other aspects of salmon aquaculture as well. We have long-standing relationships with these and other groups and continue to engage with them.

A last note

Recent media stories about genetically modified salmon have added another degree of complexity to the salmon aquaculture story. It’s important to know that Verlasso’s use of omega-3-producing yeast does not make our salmon genetically modified.  The fish currently under review by the FDA have been altered with growth-hormone genes, changing the actual DNA makeup of the fish. The DNA of Verlasso salmon has not been altered in any way; our fish have the same genes as their ancestors. We do not favor the use of genetically modified salmon in aquaculture.

At Verlasso, our goal is to not only raise the best farmed salmon, but also to be the best salmon farmers in the world. We are proud of the significant progress we’ve made in reducing the quantity of fish needed for salmon farming, as well as other steps we’ve taken to balance our needs with the needs of the natural environment.

Please use the space below for your comments or contact us directly.

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