Leticia Félix-Cuencas

The present study evaluated the suitability of black soldier fly ( Hermetia illucens ) larvae (BSFL) as a fishmeal substitute in the diets of tilapia fingerlings ( Oreochromis sp.) reared in a recirculating aquaculture system, with particular emphasis on growth performance, water quality, and...

This study evaluated productive performance, nutrient use efficiency, and nitrogen and phosphorus mass balance in an intensive aquaponic polyculture system combining Nile tilapia (Oreochromis niloticus), channel catfish (Ictalurus punctatus), lettuce (Lactuca sativa), and spinach (Spinacia oleracea) under high biomass density (40 kg m⁻³). Nine treatments were established through a 3 × 3 factorial combination of fish (tilapia:catfish = 75:25, 50:50, 25:75) and plant (lettuce:spinach = 75:25, 50:50, 25:75) species ratios and evaluated over three consecutive 60-day production cycles. Nitrogen and phosphorus use efficiencies differed significantly among treatments, reaching maximum values above 50% for NUE and 47% for PUE in catfish-dominant systems with higher spinach proportions, indicating improved nutrient recovery and reduced losses. These treatments also produced greater fish biomass, whereas lettuce-dominant combinations favored plant yield. Water quality remained within acceptable ranges, although higher catfish proportions were associated with lower dissolved oxygen and increased nitrogen availability. Overall, results demonstrate that optimizing fish–plant species ratios enhances nutrient retention and sustainable productivity in intensive aquaponic systems. Future research should explore adaptive species ratio management and economic feasibility to support large-scale implementation of polyculture aquaponics.

Accelerated population growth has driven the search for efficient food production systems such as aquaponics, which integrates aquaculture and hydroponics in a closed-loop configuration. In conventional aquaculture and hydroponic systems, intensification often causes physiological stress, nutrient imbalances, and resource inefficiencies. This study tested the hypothesis that, in an intensive aquaponic configuration, the synergy between aquaculture and hydroponic modules helps mitigate stress, improve nutrient and water use efficiency, and sustain overall performance compared to stand-alone hydroponic and aquaculture systems. The experiment was conducted under greenhouse conditions over three consecutive 180-day cycles, comparing an intensive aquaponic system with aquaculture and hydroponic modules. Tilapia in aquaponics showed 30% lower cortisol and 22% lower glucose (p < 0.05) than in aquaculture, indicating reduced stress. Tomatoes showed 25% higher catalase activity and 18% higher phenolic content (p < 0.05), reflecting moderate oxidative stress. Tilapia productivity reached 38.4 kg m⁻³ (+11.7%), tomato yield was 22.7% lower than in hydroponic conditions, and N–P use efficiencies were 23.3% and 20.7% (p < 0.05). Water use efficiency improved by 17.4%. Despite reduced plant growth, aquaponics decreased fish stress and enhanced nutrient recovery, supporting its potential as a sustainable, resource-efficient alternative for integrated food production under intensive conditions.