Produção de “baby” tambaqui (Colossoma macropomum) e microverdes de rúcula (Eruca sativa) em sistemas de aquaponia: desempenho e viabilidade econômica

Abstract

Aquaponics is a sustainable activity that has grown worldwide in recent years as a social alternative to promote food security among the economically disadvantaged population. The objective of this study was to develop micro-scale aquaponics with a native Brazilian species, the tambaqui (Colossoma macropomum), associated with the cultivation of microgreens, an agro-food trend, with arugula (Eruca sativa), aiming at the viability of subsistence family production. For 70 days, the growth performance of 80 tambaqui juveniles (average initial weight = 61.88g ± 8.31g) was monitored to obtain “baby fish” (≥ 300g). Two treatments with two hydroponics structures, Nutrient Film Technique (NFT) and Floating Raft Technology (FRT), in four replications were tested. Survival of tambaquis was 100% in both treatments and some changes in water quality were observed throughout the experiment. The final weight of tambaquis (NFT = 136.38g ± 35.67g; FRT = 116.5g ± 24.63g) was below the expected average, possibly due to factors associated with water quality. The microgreens performed better in the NFT structures (157.38g ± 21.74g; 6.68cm ± 0.17cm) compared to the FRT (41g ± 6.18g; 4.46cm ± 0.58cm), defining the best hydroponic unit for the cultivation of E. sativa microgreens. Finally, the economic feasibility study was carried out considering the expenses with structure, electricity and inputs, and a monthly family income equivalent to a wage of US$ 239.37, but in none of the scenarios considered was it possible to consider aquaponics as an activity viable in combating food insecurity for those families.