Norway’s Bellona and Leroy Seafood are working on an integrated aquaculture system called Ocean Forest that can simultaneously grow fish and plant species to create bioenergy, sustainable food, and absorb C02.
Norway is the world’s second largest farmed fish exporter, despite the fact that it still farms only one species at a time. The law prohibiting multi-trophic aquaculture dates back to a time when there was lack of understanding about the ecosystem, says Anne Lise Leonczek, leader of the innovation project Ocean Forest.
The Norwegian marine biologist at Bellona is currently spearheading an effort to see how the seafood industry can utilize the naturally growing mussels and algae around salmon farms to create a sustainable and environmentally friendly solution to fish farming. Blue mussels would be grown en masse to filter water and reduce salmon sea lice instead of chemicals, while cultivated algae would absorb CO2, produce fish food and boost fish health.
“Research around the world shows that integrated aquaculture production has a great potential,” said Frederic Hauge, Bellona leader, in its 2013 report entitled Traditional and Integrated Aquaculture. “One’s waste becomes the other’s resource and the result is fewer diseases and faster algae growth.”
The concept of producing several species in fish farming, also known as Integrated Multi-Trophic Aquaculture (IMTA), is common practice in other countries. Asia has come farthest in it use, according to the Bellona report. The Chinese for example have a project in Sungo Bay, east of the Shandong islands, where they simultaneously culture scallops, oysters, abalone, and seaweed over an eight-kilometre area.
In the western world, Canada and the US have also come far in commercial production. The Canadian Integrated Multi-Trophic Aquaculture Network has recently established a project in Vancouver Island growing fish, seaweed, mussels, scallops and sea cucumbers. In the US, a skin care company has partnered with the University in Washington to grow red algae for their products using shared seawater from halibut and cod farming.
Norway, Denmark and Sweden are still in the pilot stages of integrated multi-trophic aquaculture. Research organization SINTEF and the Norwegian University of Science and Technology NTNU completed a three-year project in 2012 on IMTA called INTEGRATE, which has been followed up by a new project EXPLOIT. Bellona, SINTEF (project leader), NTNU, and the Institute of Marine Research are part of the new three-year project studying the possibilities of combining mussels, scallops and algae with salmon farming.
Other Norwegian research projects include DYMALYS (Farming of Macro Algae in Lysefjorden) in the fjord offshore Stavanger, together with Lerøy Seafood, Bicotec, Lysefjorden Research Station, EWOS Innovation, Bellona, Sylter, Algenfarm, Blue Planet (project leader) and Norwegian water treatment company IVAR. The participants have grown high-quality macro algae that can be used for fish feed, human consumption, bioenergy, fertilizer, and absorbing CO2.
The Ocean Forest project started in September 2013 with the placement of mussels near Lerøy Seafood’s fish farm in Sotra, an island west of Bergen. The site is home to 1.6 million salmon divided among eight fish cages. Ocean Forest will also cultivate seaweed from the sea surface and grow a new ecosystem in the artificial reefs underneath on the seabed.
Algae are rich in Omega 3, necessary for fish immune support, and could spare the seafood industry the dilemma of having to use more fish to feed fish. In the future, the project may even grow small worms called polychaetes to see if they can be used as fish feed on a large scale, test the possibility of running the fish farming facilities on wave power, and place wind farms alongside the sustainable aquaculture system.
Ocean Forest will be a pioneer in many areas. Studies from Canada have shown that mussels filter bacteria and viruses and found that early stage salmon sea lice – also known as the copopodic stage – can be food for fish, much like shrimp are in the food chain, says Leonczek. Ocean Forest will be the first project of its kind to test these theories in a field study, and not just the lab.
Ocean Forest will also be the first in the world to place a large artificial reef underneath a fish farming facility. Three tons of tubing extending in spokes around a four-metre wide cylinder hub will sit on the seabed, providing an excellent environment for a biodiversity of fish and flora to grow. Algae thrive on the nitrogen and phospherous compounds that come from fish waste products. If produced on a large scale, algae could reduce CO2 and build bio-mass.
“Artificial reefs will be used to see what type of species that will settle and whether we can use them for fish food and grow other species in large scale,” saysLeonczek. “This will build biodiversity. This has never been tested before.”
The greater ambition is to make the project not just sustainable, but also carbon negative. The simultaneous cultivation of algae and shellfish will help mitigate climate change by absorbing and storing CO2. The oceans naturally absorb 20 million tonnes of CO2 every day, leading to ocean acidification. By growing one hector microalgae, the industry could remove up to 66 tons of CO2, according to Bellona.
“The world is three quarters ocean, and the sea holds the key to solving our challenges,” said Hauge. “The sea can produce bio mass for food, fish feed, materials, fuel, and pure bioenergy. Algae attracts CO2 and combats acid seas, and removes CO2 from the atmosphere.”
“If you combine production of bio energy with carbon capture and storage, the result is carbon negative, which means that the more energy you produce, the more CO2 you can remove from the atmosphere,” he added.
Caption:Ocean Forest Project
Credit: The Dude
Caption:Integrated Multi-Trophic Aquaculture with salmon, mussels, algae and invertebrates.
Credit: Minsk & Bellona