Fish farming by-products have the potential to increase the sustainability of aquaculture and contribute to other sectors such as food, diet supplements, animal feed and cosmetics, according to a new study.
Researchers from the University of Stirling’s Institute of Aquaculture found by-products, such as fish heads, frames, trimmings, skin and organs, are an underused resource that could be used in cosmetics, pharmaceuticals and even clothing.
As part of the Green Aquaculture Intensification in Europe project, Stirling PhD researcher, Wesley Malcorps, found that commonly farmed species like Atlantic salmon, European seabass, gilthead seabream, common carp and turbot were being routinely wasted in industrial and household processing.
“Although fish by-products don’t sound appetising, they are full of goodness and can be used for many purposes – including in food supply and diet supplements. Our results show a substantially higher total flesh yield (64-77%) can be achieved if fish are fully processed, compared to fillet only (30-56%), as is often the case,” said Mr Malcorps.
By-products can be used in soups or processed foods such as fish fingers, as well as pet food, protein powders, fish oil and collagen supplements. The study also found uses in the cosmetic, pharmaceutical, packaging and clothing industry, where fish skin can be used as an alternative to leather.
Importantly, one third of marine ingredients used in feed for farmed fish originates from by-product. This amount could be increased, greatly reducing the environmental impact of aquaculture, finds the study.
