Designing circular food systems is seen as a promising way to reduce the pressure of food systems on ecosystems. In circular food systems, biomass from arable land and water bodies is prioritised for human food and other basic needs, rather than animal feed (Boer & Ittersum, 2018; Muscat et al., 2021; van Zanten et al., 2019). Along this paradigm, farm animals, including aquaculture species, should not consume human food, but instead convert by-products from crops, livestock, and fisheries that are inedible for humans into edible biomass.
Previous research on food system modelling has primarily focused on livestock, while aquaculture can also play an important role in circular food systems. In aquaculture, species from a wide range of trophic levels can be cultivated, opening various opportunities for upcycling of food system by-products.
Our aim is to determine the role of aquaculture in circular food systems in Europe. We will use circular food system modelling to gain insights into which aquaculture species could be produced, how much aquatic food can be produced when animals are fed exclusively with food system by-products and what by-products can be recycled as fish feed.
Materials and Methods
We used a resource allocation model to allocate by-products (including by-products from fisheries), food-waste (derived from the EAT-Lancet diet) and grass resources to livestock and aquaculture species (fig 1.) to maximise animal source protein (objective). Livestock systems included in the model were based on van Hal et al., (2020) and van Selm et al., (2022), whereas we developed individual growth models for four commonly produced species in Europe: Atlantic Salmon (Salmo salar), European seabass (Dicentrarchus labrax), gilthead seabream (Sparus aurata) and blue mussel (Mytilus edulis). To this end, we used DEB modelling to estimate the growth and energy requirement of each species for different water temperature conditions representing marine-producing areas in Europe. Preliminary results of the model on what by-products can be recycled as fish feed and which aquaculture species could be produced will be presented
Boer, I. J. M. de, & Ittersum, M. K. (2018). Circularity in agricultural production. https://edepot.wur.nl/470625
Muscat, A., de Olde, E. M., Ripoll-Bosch, R., Van Zanten, H. H. E., Metze, T. A. P., Termeer, C. J. A. M., van Ittersum, M. K., & de Boer, I. J. M. (2021). Principles, drivers and opportunities of a circular bioeconomy. Nature Food 2021 2:8, 2(8), 561–566. https://doi.org/10.1038/s43016-021-00340-7
Van Hal, O. (2020). Upcycling biomass in a circular food system – the role of livestock and fish –. PhD thesis, Wageningen University, The Netherlands.
van Selm, B., Frehner, A., de Boer, I. J. M., van Hal, O., Hijbeek, R., van Ittersum, M. K., Talsma, E. F., Lesschen, J. P., Hendriks, C. M. J., Herrero, M., & van Zanten, H. H. E. (2022). Circularity in animal production requires a change in the EAT-Lancet diet in Europe. Nature Food, 3(1), 66–73. https://doi.org/10.1038/s43016-021-00425-3
van Zanten, H. H. E., van Ittersum, M. K., & de Boer, I. J. M. (2019). The role of farm animals in a circular food system. Global Food Security, 21, 18–22. https://doi.org/10.1016/j.gfs.2019.06.003