The global human population faces big societal challenges: its growth demands for huge increases in food supply, which should be nutritious, healthy and accessible for all. Thanks to its strong innovative capacity and intensification, food production has kept pace with this growing demand. At the same time, global effects of climate change, loss of biodiversity, land and soil erosion, ocean acidification etc. demonstrate that the borders of our planetary resources are at reach. Therefore, our food production needs a paradigm shift, from production efficiency towards a focus on resource use efficiency.
The importance of aquatic foods for global food and nutrition security has received much attention in recent years (e.g., the CFS 2014 ; UN Nutrition Discussion paper on the role of Aquatic Foods 2021; The UN Food System Summit, the World Food Prize, Golden et al. 2021 ). As the extraction of natural populations from the oceans and inland waters has reached its limits, aquaculture is considered as the main source for future supplies of these aquatic foods. Just as for any other form of food production, the required paradigm shift counts also for the production of aquatic food through aquaculture. Circular approaches are considered as a possible solution to produce food within the context of the planetary borders, environmentally healthy and sustainable.
Circular systems are characterized by inputs which are derived from waste products from another resource, which can be terrestrial, aquatic or even abiotic. They are therefore ideal to connect the aquatic food system with the much larger green/terrestrial one. Examples are the traditional Asian fish-cum-animal integrated pond system or the modern fish-cum-hydroponic system (so-called aquaponics) and its marine equivalent IMTA (integrated multi-trophic aquaculture). The level of integration, or circularity, depends on the spatial scale of governance. The above examples are typical for the level of farm units, but at a regional or even national scale, other opportunities for developing circular systems can be found, by combining the operations of different farms, or organizing the collection, processing and distribution of waste products for their use in other commodities. A prominent role in this seems to be allocated to the feed industry, thereby relying on necessary inputs from fish nutritionists. Left-over stream products from the agro-food industry may be valorized as an ingredient for aquafeeds, provided that they are nutritionally safe and valuable. Intermediate steps might be required such as the use of insect meal derived from insects growing on these waste products.
In the presentation, the concept of circularity will be discussed at the different scales of governance, and examples presented with a particular reflection on their feasibility for Africa.
References
Golden, C.D., Koehn, J.Z., Shepon, A. et al. Aquatic foods to nourish nations.Nature 598, 315–320 (2021)
UN Nutrition, 2021. The role of aquatic foods in sustainable healthy diets. Discussion paper, 58pon the role of Aquatic Foods 2021;
Committee on World Food Security 2014 . Sustainable Fisheries and Aquaculture for F ood security and Nutrition. Policy Recommendations, based on CFS-41 Final Report.