LAUSR

Abstract As the demand for fish increases and limitations are placed on water use, intensification in closed aquaculture systems could help to increase its sustainable production. The Amazon region stands out for its stable warm climate with fast-growing and resilient fish. This study evaluated the efficacy of two aeration regimes on intensive rearing of tambaqui, Colossoma macropomum, in six 46.4-m3 concrete-wall earthen bottom ponds, with no water exchange. Two aeration regimes were tested: (1) emergency aeration (EA), in which the aeration system was activated with dissolved oxygen (DO) levels below 3 mg L−1; (2) supplemental aeration (SA), with 8 h of aeration every night, and also during days with low solar radiation. Water quality, fish performance and health (haematological and parasitological indicators), aeration use and cost were assessed. Juveniles (44.39 ± 9.72 g, mean weight ± SD) were stocked in six concrete-wall ponds with earthen bottoms at 32,300 ha −1 and fed commercial feed (36–32% crude protein) for 17 weeks (122 days). Mean values of the water quality parameters showed no difference between treatments, but occurrences of hypoxia were significantly higher in SA (31 hypoxias with DO