Fish, Feed, and Food in the Fjords

Oct 12, 2017 | Food and Nutrition, Global Food and You | 0 comments

The Dirt:

D2D recently had the opportunity to visit salmon farms in Norway. We were able to experience the impressive undertaking of these aquacultures first hand. Unfortunately, the sustainability of farmed salmon continues to be misunderstood. So, we are thrilled to be able to share this experience with our readers and help educate on this important industry.

As consumers, we still have a lot to learn about salmon farming. For example, when searching for “farmed salmon” on the internet, consumers are quickly advised to choose wild salmon over farmed salmon. And while this recommendation may have been valid 20 years ago, salmon farming practices have changed significantly.

D2D touring the salmon pens!

The average consumer’s understanding of farmed fish has not kept up with the ever-improving salmon initiatives. For example, collaboration efforts amongst salmon farmers have drastically improved and the standards for salmon sustainability are now globally recognized. This communication is primarily facilitated by the Global Salmon Initiative (GSI). Specifically, the GSI fosters collaboration among salmon farmers in 8 different countries— nost notably Norway, Scotland, and Chile, the primary producers of farmed salmon.

As we discussed in Wild vs. Farmed Salmon, farmed salmon that has been raised sustainably, safely, and healthily will be labeled with the Aquaculture Stewardship Council (ASC) certification. But, the importance and insurance of this label is typically overlooked when consumers are purchasing salmon for their dinner. Farmed Atlantic salmon provides 50% of the total global salmon market! It is time to bring the accomplishments and advancements of salmon fisheries to life…

All Aboard!

Recently, D2D visited Norwegian salmon farms to learn about the technology that goes into producing healthy farmed fish. Let’s take a journey to the homeland of Norwegian farmed salmon. We will explore how the salmon are fed, how that affects their health, and the impressive technology that makes it all possible to bring this food to your plate.

Salmon farms are scattered along the Norwegian coast.

The beautiful Fijords. (Image source:

In 2016, Norway processed 1.1 million tonnes of salmon. Chile is a distant second producer of Atlantic salmon with approximately 450,000 tonnes harvested in 2016. The US imports about 18% of its salmon from Norway.

Norway is the top supplier of farmed salmon to the world. Every single day, Norwegian salmon is on the plate of 14 million consumers in 140 countries! The fisheries, feeders, processors, and distributors in Norway have set the highest standards for sustainable farmed salmon around the world.

Salmon farms are scattered along the Norwegian Fjords. They provide a perfect environment for salmon because of the cool water temperatures (ranging from 32°F to 68°F) and the strong current that flows through the farms. Salmon farm operations range from the smaller family-owned business, with roughly 8-10 farms, to larger corporate farms, with over 100 farms under their management. In Norway, the top 10 salmon farmers compromise 69% of the total volume of salmon produced.

Life of the Farmed Salmon

Your fresh salmon was probably caught and frozen within the past three weeks, but it took three years for the salmon farm to plan and produce that particular fish. In a salmon’s first year of life, the eggs are fertilized and the fish is grown to about 3.5 ounces in a fresh water environment. They are held in this fresh water habitat for roughly 10-16 months. After the first year, the fish are transferred to the open salt water cages where they will stay for about two years until they are harvested.

Fertilized Salmon eggs!

Baby salmon

In order to better understand the impressive undertaking of the salmon farmer, D2D traveled up a spectacularly beautiful fjord to visit a salmon farm near Bergen, Norway. Each individual salmon farm has about 6-8 ‘floating pods.’ These pods are netted pens that are 650 wide and 165 feet deep. Each pen holds about 200,000 salmon. The pens provide the fish with ample space to swim and grow. Norwegian law prevents overcrowding and insists upon a ratio of 2.5% fish to 97.5% fresh water. This leaves plenty of room for the salmon to swim and jump within the confines of the pen.

Salmon pens. The black lines send the feed to the fish in what looks like a spinkler.

Did you know? Salmon must jump to fill their swim bladders with air so they can manage their buoyancy.

During our visit to the pens, a small boat took us to the rubbery catwalk that surrounds the pod. The catwalk is just wide enough, about 3 feet, so that one has room to inspect the net, the fish (from above) and the food distribution. A large sprinkler-like device spins the food out to the fish. The salmon are fed approximately 60% of their diet in the morning and 40% in the afternoon.

The pens are specifically designed to protect the fish. The high nets over the pens keep out the birds and keep the fish from jumping out into the open water. The nets are also expanded underneath the water to keep the fish in and the sharks out!

Sea lice is a problem for both wild and farmed fish because they affect the salmon’s immune system. Norway’s law allows a maximum of .2 sea lice per fish. There are several methods to protect the salmon and combat sea lice. These include releasing Pilot fish into the pods where they eat the sea lice off the salmon; keeping a pod free of fish for three to six months after harvesting, and adding a treatment called SLICE to the feed which prevents the sea lice parasites from feeding on the fish. This is out of the salmon’s system well before harvest.

Monitoring the Fish

Each salmon farm has its own stationary barge anchored next to the farms, which doubles as a feed storage and fish monitoring site. Silos within each barge hold customer-specific feed that cater to the different life stages of a salmon. The barge also contains feed lines, which are thick hose-like structures that transfer the feed from the barge to each of the cages. Additionally, most barges have a control room with about six screens that watch the fish swim via underwater cameras. They constantly monitor the health and size of the fish, the water quality, feed distribution, and the seafloor bottom. This careful monitoring reduces the amount of fish waste and food to litter the bottom. Fish waste used to be seen as a deterrent of fish farming—but today, with better management and feeding practices, the nutrient waste cannot be detected outside a 100-yard perimeter of the site.

The sophisticated barges that monitor growing salmon.

Salmon are monitored constantly from aboard the barges.

The boats also use scuba divers to make sure the nets surrounding the cages are clean of debris and secure any holes that may allow the fish to escape. Salmon escapees can be an issue if they breed with the wild fish as they can adversely affect the wild salmon’s natural navigation systems. Because of this, allowing salmon to escape from the pen is illegal under Norwegian law. Salmon escapees must be reported, counted, and recaptured.

What is in the Fish Food?

The primary objective of creating the ‘perfect’ fish food for the salmon is to ensure high muscle growth, keep a strong immune system, and to be able to have at least a 1:1 conversion rate from feed to salmon protein— all within three years.

It takes approximately 1 pound of fish feed to grow 1 pound of salmon protein, although this can vary slightly depending on the feed mix. Salmon, like most fish, are some of the most efficient converters from feed to protein. Feed innovation continues and some formulas have shown an even lower conversion rate, meaning .90 pounds of food converts to 1 pound of salmon which might not seem like a lot of change but it is significant.

Each fish grows to about 14 pounds by the time they are harvested. After slicing the meat, each salmon yields about 9-10 pounds of fish for your dinner.

Source: Marine Harvest

Source: Marine Harvest

Fish are carnivores and rely on fish oil and fish meal for their feed. However, using wild fish in order to help feed farmed fish is not sustainable. 20 years ago, 70% of the fish oil and meal came from wild-caught fish, today that number has dropped to approximately 30%. Of the fish used in the fish feed, 90% comes from regulated fisheries and are fish that are not on the World Conservation Union’s list of endangered species. Additionally, the fish used in the fish feed are not targeted for human consumption.

Salmon feed is a nutritious source of vitamins and minerals. Image source: EWOS


The salmon feed industry’s innovations replicate the fish oil and fish meal found in regular fish with alternatives to still give the salmon the healthy high omega-3 fatty acid, EPA, and DHA found in fish oil. The fish meal also contains minerals and vitamins. Finally, vegetable ingredients such as algae, non-GMO soybeans, peas, sunflowers, or canola are used to help supplement the fish oil. The rest of the feed consists of vitamins, minerals, and amino acids. The feed is all compressed, using starch as a glue, into salmon bite sized pellets. It is important to get the consistency correct as the pellets can break apart in the loading and unloading or during the feeding process.

The three largest feed producers in Norway are BioMar, Skretting, and EWOS: comprising 84% of the market. Each have their own innovation centers which work closely with suppliers to verify sustainability and develop optimum feed for the growth phases of the salmon.

Contrary to what is read on the internet, antibiotics are not allowed to be used in Norwegian farmed salmon. Instead, the fish are vaccinated as babies – which prevents the need for antibiotics as adults.


 Delivering the Feed

In addition to our time spent touring the pods, we also spent a day north of the Arctic Circle in Botnhamn, Norway delivering feed to one of the salmon farms. As we motored along in one of the large ships, we were lucky to have calm seas and sunny skies. The water was so clear you could see jelly fish floating well below the surface. As the sun sparkled over the water, we were told that this weather is very rare. Many days there is high wind and seas and the days are cold and wet. It can be a harrowing trip, with waves so high that they splash up on the bridge window. Regardless of the weather, however, the fish must be fed. So the ships travel from the farm to the processing plant two or three times a week.

There are 26 vessels that supply the entire salmon market. The combined feed loading capacity is 34,000 tons. The ships lengths range from 150 – 200 feet. They carry anywhere from 600 to 1800 tons of fish feed and go about 10 knots an hour. Every year each ship will do at least 100 voyages— feeding about 30 farms. Image: EWOS

Life of a crew on a feed delivery ship: The crew are divided into two teams where they have three weeks on board and two weeks at home. There are six to eight crew on each ship. It is not a fast-paced job, and when the weather is calm, can be even be fairly relaxed during the two-hour feed transfer to the barges. The crew are mostly men, but sometimes they bring along their wives. Often the crew will fish for dinner – on the opposite side of the salmon pens. There is a chef and some boats have a jacuzzi. The ages range from 18 years old to the 60s. While most of the deliveries are in the summer – salmon do not eat as much in cold weather – the weather can still be rough and cold.

Regardless of the weather that faces these shipments, the ship picks up feed from the fish feed processing plant and delivers it to the barges all along the Norwegian coast. It is a long coast – each single voyage is equivalent to traveling from Minneapolis to Miami, roughly 1,800 miles! Imagine, each year, circling the earth two times around the equator. That is how many miles the salmon feed ships log each year.

When grown sustainably, farmed raised salmon are a great and delicious choice for any meal!

The Bottom Line: 

Farmed fish, raised sustainably, is a great source of protein and a necessary part of the world’s protein diet. The World Bank projects farmed fish to be 60% of the fish on your fork by 2030. Next time you are at the grocery store, know that farmed Norwegian salmon is made with healthy ingredients and grown in sustainable waters.  


    1. FAO Fisheries & Aquaculture Salmo salar, 1 Jan. 2004,
    2. “Homepage.” Global Salmon Initiative,
    3. “Seafood Watch – Official Site of the Monterey Bay Aquarium’s Sustainable Seafood Program.” Seafood Watch – Official Site of the Monterey Bay Aquarium’s Sustainable Seafood Program,
    4. “Start page.” Start page,
    5. “Welcome to EWOS Group.” EWOS | Welcome to EWOS,