The makeup of salmon fish feed has changed radically over the last decades. According to the Norwegian University of Life Sciences (NMBU), the diet composition from marine protein has shrunk from 65% in 1990 to just 18% in 2013, while the use of plant protein and oil has skyrocketed to make up more than half of all feed in Norwegian salmon farming. The majority of fish feed currently comes from soybeans and rapeseed. According to researchers that is not sustainable in the long-term.
COMPETITION FOR RESOURCES
The needs of a growing global population – particularly the middle class – will put pressure on the competition for food resources. In order for the aquaculture industry to grow, more alternative sustainable feed sources will need to be found. Norwegian farmed salmon production alone is predicted to more than triple from 1.3 million tons to 5 million by 2050.
“In order to produce more salmon, we will need to produce more fish feed – without using feed ingredients that could be used for human consumption,” said Aud Skrudland, HAVBRUK 2 board chairperson and special inspector at the Norwegian Food Safety Authority. “This will entail research on utilizing species at lower trophic levels such as macro- and microalgae and mollusks as well as marine species such as cod and cleaner fish.”
The Research Council of Norway has highlighted fish feed research as one of seven priority themes under its recently launched large-scale aquaculture program HAVBRUK 2. The ten-year follow-up program to HAVBRUK was the largest funding announcement for aquaculture research in the history of the Research Council of Norway. The greatest change under the new program included more efforts to produce aquatic biomass and new species.
One of the species most difficult to farm has been the Atlantic Bluefin tuna. Unlike salmon fry that thrive on dry feed, tuna requires live feed. Norwegian company C-Feed has developed a commercial copepod production system that has made it possible to supply eggs from the tiny crustacean Acartia tonsa (also known as sandhoppers) to feed juvenile tuna larvae on an industrial scale. It was one of the 34 research and innovation projects to receive the first round of NOK 190 million in funding at HAVBRUK 2 in December 2015.
C-Feed’s value proposition decreases mortality rates in very early stages, increases growth, and produces healthier fish. Fish farmers have tried raising tuna using live feed organisms such as Artemia (commonly known as brine shrimp), but found growth deformations in the jawbone, tail fin and vertical column. Studies at the Norwegian research center SINTEF found there were fewer abnormalities when using copepods.
“The tuna is very particular with what it eats and needs a lot of it,” Espen Müller, C-Feed chief executive, stated in an interview. “Tunas grow a lot in the first 40 days.”
C-Feed expects that tuna aquaculture will be an important market, particularly in Mediterranean countries such as Spain and Greece. Most of the tuna currently raised stem from wild catches of small juveniles bred to harvestable size.
In Norway the main markets are halibut and Ballan wrasse, a cleaner fish sought by salmon farmers because it eats salmon lice. Copepods have been found to increase the survivability rate of farmed halibut in the first month from 10% to 60% and improve the growth, survival rates and stress tolerance in ballan wrasse compared to being fry fed with traditional live feed.
“It’s been known for some time that the nutritional value is higher in copepods (than Artemia and rotifers),” Müller said. “The problem so far has been that there has been no supplier.”
C-Feed currently sells both eggs and live copepods in Norway and exports eggs to the Mediterranean market from SINTEF Sea lab in Trondheim. The company will dramatically expand production after it opens the world’s first commercial copepod plant in February 2016 in the county of Leksvik near Trondheim. The facility is expected to produce enough eggs to raise 50-60 million farmed fish.
TREES AS FISH FEED
Another recent initiative is Foods of Norway, a Center for Research-based Innovation at NMBU. Officially opened in September 2015, the center will develop new, innovative bio-refining techniques to convert natural bio-resources into high-quality feed ingredients for fish and farm animals over an eight-year project period (2015-2023) together with five international partners from Denmark, the U.S. and Australia, as well as 14 industry partners.
Margaret Øverland, Foods of Norway’s CEO, believes there are many exciting options for new types of fish feed that will provide for more sustainable fish farming. In her presentation at Marine Innovation Day in Oslo last October, she pointed to recent advances in microbial ingredients for fish feed, such as yeast from trees and bacteria meal from natural gas, as well as micro and macro algae.
Norwegian biochemical company Borregaard, one of Foods of Norway’s industry partners, will provide sugar from Norwegian spruce and yeast biomass for in vivo testing of fish and farm animals. The yeast will be fermented from the cellulose and hemicellulose found in coniferous trees.
“Over half of this country is forest,” Øverland said. “If we use our forests to produce fish feed we will be less dependent on imported raw products such as soya from Brazil.”
Previous research has demonstrated that yeast has several positive health effects compared with soy as a source of protein. According to Øverland a three-month study using three types of yeast in salmon feed at NMBU found that candida utilishad the same protein digestibility as fishmeal. It also proved better than soy for fish gut health.
Yeast produced from trees could replace up to 40% of the protein in fishmeal in diets for Atlantic salmon. However, a main challenge will be price as production costs are too high for yeast to be a competitive product as a new protein source. Another concern will be ensuring that trees are harvested sustainably.