Norway to develop fish food from captured carbon dioxide

A project that turns captured carbon dioxide into food for farmed fish is to be tested in Norway.

It involves producing Omega-3 fatty acids from algae that will be grown in a stream of CO2 at a test facility.

At present the oil is produced for aquaculture from low value fish or krill caught in the waters of Antarctica

But the new technique could absorb the gases responsible for global warming while providing sustainable fish food.

Seafood is Norway's second largest export after oil and gas, valued at over $10b in 2013.

The fjords produce around 60% of all the farmed Atlantic salmon in the world.

Business is booming with the world's appetite for aquaculture showing little evidence of a slowdown. In fact, current predictions indicate that farming for fish will overtake the traditional wild fisheries in the next couple of years.

However, one of the big challenges for the continued growth of the industry is a ready supply of Omega-3 fatty acids. Fish normally accumulate these chemicals by ingesting algae, phytoplankton or prey fish as they grow.

Farmed fish, grown in large numbers in nets, aren't able to gather Omega-3, so have to be supplemented in their feed.

But the fish farming industry isn't the only one looking for Omega-3. It's also much in demand for human health supplements and in the pharmaceutical industry.

As a result, prices have risen and supplies have struggled to keep up. Krill, caught in the cold waters off Antarctica, have become the focus of intense interest for fishing boats in recent years, leading to concerns over the sustainability of the species.

Pure streams

Now a Norwegian consortium, formed by some of the biggest sea food companies in the country are developing the Omega-3 project, backed by $1m from the government.

The installation will be built at Technology Centre Mongstad, the world's largest test facility for carbon capture and storage technologies.

The Mongstad centre, built as a joint venture between the government and several oil companies, has had a chequered history.

It's made up of two CO2 capture plants that can remove 80,000 tonnes of the gas from a nearby refinery and 20,000 from a gas fired power plant.

Last year, the Norwegian government announced they were cancelling the installation of a full scale carbon capture and storage facility there, citing delays and increasing costs.

However the backers of the Omega-3 project believe Mongstad is the perfect location to test their technology.

"We have a tank collecting in CO2 and algal mass, mixed with sea water, at a temperature of about 25 degrees C," said Svein Nordvik, from CO2BIO, the company set up to run the project.

"There are other methods and techniques but at Mongstad we have the advantages of pure CO2, sea water and steam so the opportunity to develop this will be better there than other places."

The warm "soup" will see the algae grow rapidly. It will then be harvested, dried and processed for the oil it contains.

According to the backers, a tonne of CO2 will produce a tonne of algal mass from which they believe they can get 300-400kg of oil at present.

They hope to improve this over the five-year life of the test project. They will then be able to decide if the process is economic or not.

"The CO2 is a problem for the climate and we can use it to produce food," said Mr Nordvik.

"Today most of the Omega-3 oil is produced in Peru and other countries, and that is not sustainable.

"The need is approximately 100,000 tonnes, and that's a large scale. The reason for the test centre is to develop the techniques and optimise the production line so we can have a decision on large scale production."

The Omega-3 problem has also attracted the attention of British scientists.

Earlier this year they announced a plan to grow a genetically modified crop of camelina that would produce an oil rich in the fatty acids.

Follow Matt on Twitter @mattmcgrathbbc.