According to France Agrimer, in 2018, the volumes of by-products generated in France on the fisheries and fish farming sectors were 152,561 tons/year, including 15,000 tons in the Atlantic region. Among the species, salmonids (excluding salmon) were produced to the tune of 34,564 tons at the national level, 96% of which were rainbow trout. Their processing generates 15,392 tons of by-products, representing about 50% / production whose main ways of valorization are currently those of animal feed and petfood. This species was chosen as a study model to propose, thanks to the Sea2Land project, a joint valorization of proteins in the form of bio-based fertilizers (BBF) and lipids for higher value-added applications. This double valorization is made possible through the use of a thermomechanochemical transformation process (TMC) by twinscrew
extrusion. It would be extendable to any species of fish, produced on the Atlantic coast.

According to the France Agrimer 2018 report, the estimated ratio on the main salmonid byproducts (excluding salmon) is 53/32/15 viscera/bones+flesh/heads. In this case of study, the ratio of by-products from the Ispeguy fish farm is 38/28/34. The determination of the chemical composition of the 3 types of by-products (n=3) validates the development of a joint protein/ lipid valorization process.

Fig 1: Chemical composition of Steelhead trout’s by-productsBiorefininery scheme
Fig 2: Fish Farming by-products (Steelhead trout)

Further information: Evaluation des ressources en biomasse aquatique disponibles en France – co-produits et sousproduits – Volumes 1&2 – 2021- France Agrimer.
Ahuja, I. et al, Fish and fish waste-based fertilizers in organing farming – With status in Norway: A review. Waste Management 115 (2020) 95-112.
Authors: Candy Laure & Raynaud Christine / CATAR
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