When we talk about food security we tend to think about livestock or land production. However, many people around the world, especially those in coastal areas, also heavily rely on fish and seafood. In some countries, fish accounts for more than 25% of animal protein intake and some low-income countries depend on fish as a staple food even more.
Fish farming – or aquaculture is probably the fastest growing food-producing sector and is practised both by multinational companies and smallholders. You might consume more fish from aquaculture than you think – whether you are a fan of sushi or prefer fish and chips, most likely, every other fish on your plate was produced on a fish farm. Today, almost half of the world’s fish comes from aquaculture. This fact looks even more impressive when we put it into perspective – back in the 1970s, aquaculture produced only 6% of all food fish. Moreover, the demand for farmed fish is predicted to rise further because of an emerging global middle class alongside increasing population.
I am a big fan of sushi myself and that in combination with the rising global demand for fish got me interested in looking at fish farming more closely. I had an opportunity during my bachelor’s studies in environmental science when I participated in an experimental research study for my thesis. One of my teachers, Prof. Håkan Olsén at Södertörn University was looking for two students who would continue his research work on sustainable fish feed. So I, together with another equally enthusiastic student, whom I was lucky to get to know thanks to the project, carried out this exciting experiment.
Coming into the project we believed, as many people do, that increased fish farming although not free of ecological impacts, relieved pressure from ocean fisheries. However, we soon came to learn that some aquaculture systems put even more pressure on wild fish stocks. This is greatly due to the high demand on carnivorous species such as tuna and salmon, that require large inputs of wild fish for feed. At the same time, 53% of the world’s fisheries are already fully exploited due to overfishing. So, to contribute to a more sustainable future, our experiment set out to examine if fish can be brought up on a diet consisting of mussel meal instead of fishmeal and fish oil.