The fish you ate for dinner has also eaten fish for its dinner; however, given the fact that our seas are being overfished, we need alternatives to using fish in feed. One new method is top produce fish feed from wood.
Recently, the world's first factory was ready to test protein production using natural gas. The protein will replace fishmeal, a protein source in fish feed. This new natural gas-based protein production process is only one of the alternatives being sought for the production of fish feed; wood is another. RISE researchers have been conducting studies into the possible use of forestry products for manufacturing fish feed for a number of years.
“Although manufacturing protein using natural gas is admittedly one alternative.the raw material is fossil based and therefore causes greenhouse gas emissions. Instead, what we have done at RISE is to develop fish feed from a fossil-free raw material, namely the forest,” explains Björn Alriksson, group manager for biotechnology at RISE Processum.
Fish are satisfied
The concept involves turning forest biomass into fish feed by growing a protein-rich microorganism on forestry byproducts. Researchers utilise byproducts from biorefineries or sawmills, for example branches and treetops. A number of projects are currently underway and the method has been tested at a biorefinery in Örnsköldsvik, northern Sweden. A demonstration facility is also planned in France. Even if work is still in the research phase, results are promising.
“Yes, in the tests we have conducted on tilapia, the fish grew just as well or, in certain cases, even better when eating the feed prepared by us. We have also conducted trials on salmon and trout. This study is no yet complete, but even here we are seeing very promising results,” says Björn Alriksson.
More food for us means more food for the fish
As our population grows, so does the need for food; according to a report from the Swedish Board of Agriculture, the consumption of fish has increased over the past 50 years. Increased consumption requires more fish farms and more fish feed, the protein content of which generally comes from plants and fishmeal. Fishmeal is produced from fish scraps deemed unsuitable for human consumption.
“In itself, fishmeal is good for making fish food; the problem is that 80% of the oceans have been exploited, overexploited or depleted of stock and we quite simply can’t increase fishing any more. The fishing industry has previously demonstrated a willingness to replace fishmeal with soya protein but this is not the optimal solution, as soya is often grown on rainforest land in South America,” explains Björn Alriksson.
Disrupting marine ecosystems
Overfishing impacts on marine ecosystems and can even lead to an increase in eutrophication. We need to replace fishmeal and soya protein and many companies have demonstrated an interest in the work of RISE Processum to develop a new protein from forestry products.
“We are collaborating on this issue with a number of companies, universities and institutes, as well as with RISE PFI in Norway. The collaboration with Norway has the advantage of utilising their large aquaculture industry and our own large forestry industry, meaning we can achieve a great deal together!”