The Arctic University of Norway (UiT) announced on its researchers have created a new type of feed that makes salmon less attractive to the lice.

Hans Christian Eilertsen from UiT and his colleagues Sten Siikavuopio and Ragnhild Whitaker from the Norwegian research institute Nofima tested different types of salmon feed to see if algae-based ingredients could reduce the lice spread in the cages.

Testing, testing

The research was conducted on roughly 100 salmon in four trial facilities. The fish were divided into groups and fed four different types of feed: plant-based feed, fish protein and oil, and other marine oils. The final group was fed with UiT and Nofima's algae-based feed.

"We then added the same amount of salmon lice to each vessel," Eilertsen said.

The theory, according to Eilertsen, is that the fatty acids like those found in the UiT and Nofima feed will oxidize into "a substance that lice stay away from."

The research has mostly involved diatoms, a common group of microalgae that have adapted to lighting conditions in the Arctic.

"We have grown them with (an aim) to finding a species that are well suited for mass production of marine fatty acids," said Eilertsen.

"To survive in the dark, these algae are very effective producers of so-called lipids, or fatty acids, according to the report.

Perfect 'environmental agents'

The diatom algae also have another positive characteristic.

“When it's light, they take up CO² very effectively," said Eilertsen.

"The effect is greater the colder it is in the water, making the Northern diatom algae perfect 'environmental agents.' They absorb CO² from the water, thus purifying the water for this harmful gas."

Eilertsen has been researching algae for over 40 years, and is now professor emeritus at UiT.

"We cannot continue to feed fish with fish," he said.

"Fish feed from algae, on the other hand, is both healthy and natural, because it provides the fish with the polyunsaturated fat it needs."