Solid waste management in recirculating aquaculture systems: A dietary approach in yellowtail kingfish Seriola lalandi

Summary

Between 1990 and 2020, aquaculture production was responsible to meet the increasing demand in fish and seafood consumption. To minimize negative effects of increasing aquaculture production, recirculating aquaculture systems (RAS) are seen as a way to reduce the impact on the environment. Effective solid waste management in RAS is essential for sustainable aquaculture growth, particularly concerning animal welfare and environmental impact. Solid waste primarily originates from undigested feed, thus faeces. This thesis investigated factors affecting faecal waste production and faecal integrity in yellowtail kingfish, a species with poor faecal integrity. It was shown that dietary interventions can alter faecal integrity, offering opportunities to reduce solid loads in RAS. Investigations into starch levels demonstrated significant effects on faecal waste production, removal efficiency and fish performance, indicating potential limitations with high starch diets in yellowtail kingfish. The findings of this thesis underscore the importance of feed formulation on waste management for yellowtail kingfish, especially in RAS.