Aquaponics as a Sustainable Approach for Producing Mahogany (Swietenia macrophylla) Seedlings with Effluent from Tambaqui (Colossoma macropomum) Farming

Aquaculture in the Amazon region has considerable potential to promote the sustainable use of natural resources. The integration of fish farming and forest has emerged as a resource-efficient strategy for sustainable production. This study aimed to evaluate the growth of mahogany (Swietenia macrophylla) seedlings in integrated systems with tambaqui (Colossoma macropomum), using different spacings (5, 10, 15, 20 and 25 cm) between seedlings. After 56 days of cultivation, dissolved oxygen, conductivity, total ammonia, and nitrate were significantly affected in the systems (p < 0.05). Tambaqui growth performance differed significantly between the aquaponic systems (p < 0.05). Regarding mahogany seedlings, root fresh mass, collar diameter, and the Dickson quality index were also significantly affected by the treatments (p < 0.05). The results demonstrate that aquaculture–forestry integration, using tambaqui effluent as a nutrient source for mahogany seedlings, is a technically viable and environmentally promising production strategy. Among the treatments evaluated, the 25 cm spacing produced seedlings with superior quality attributes, suggesting that wider spacing may promote seedling development under aquaponic conditions. These findings highlight the potential of integrated aquaponic systems for the sustainable production of both forestry and aquatic resources in the Amazon region.