Nitrogen budget in integrated aquaculture systems with Nile tilapia and Amazon River prawn

Abstract

The present work aims to describe the nitrogen (N) budget in integrated aquaculture systems with Nile tilapia (Oreochromis niloticus) and Amazon River prawn (Macrobrachium amazonicum) in earthen ponds, with and without the addition of different substrates. The experimental design was completely randomized, with three treatments (without a substrate, with a geotextile fabric substrate, and with a bamboo substrate) and four replications. Diet was the major input of N in the systems, ranging from~65 to 71% and followed by inlet water (~26-31%). The portion retained in reared animals and periphyton ranged from~21 to 25% (being~21-24% in fish and prawns). The outputs that contributed most to the accumulation and release of N were, respectively, sediment (~24-38%) and N2 (~30-36%) emitted to the atmosphere. The addition of substrates did not improve the accumulation of nitrogen in the biomass of the target species. This suggests that the periphyton had a minor role on feed availability. In general, the systems were not efficient in using nitrogen since only~22% of all available nitrogen was retained into prawn and tilapia biomass. On the other hand, the emission of N 2 (an inert gas) to the atmosphere almost compensated the nitrogen supplied in the diet that was not assimilated by the reared animals and periphyton. In addition, data suggest that the integrated aquaculture in stagnant ponds may sequester substantial amounts of nitrogen from nutrient-rich aquatic environments and could be used as a mitigation tool.

The budget of nitrogen in the grow‐out of the Amazon river prawn ( Macrobrachium amazonicum Heller) and tambaqui ( Colossoma macropomum Cuvier) farmed in monoculture and in integrated multitrophic aquaculture systems

“…The nitrogen of the harvested prawn biomass was similar between the monoculture (~30 kg N/ha) and the IMTA (~22 kg N/ha), but the nitrogen retained by the prawns in IMTA is a 100% gain since no feed was supplied to the prawns during the entire culture cycle. The Amazon river prawn stocking density of the IMTA (30 prawns/m 2 ) was an increase from the 21.5 prawns/m 2 used in prawn‐tilapia IMTA in David et al (), suggesting that intensification of this prawn species improved the nutrient recovery from all system compartments, from 12–15 kg N/ha in the prior study to ~22 kg N/ha of the present study.…”

“…Nevertheless, the total harvested biomass of both integrated grow‐outs showed a more favorable recovery of the feed nitrogen when compared to the monocultures. The IMTA also increased the recovery of feed nitrogen when compared to the prawn‐tilapia IMTA (~30%–36%) studied in David et al (), which suggested that intensification of the M. amazonicum in IMTA leads to the increased use of the feed nitrogen.…”

“…The inlet water accounted for the highest proportion of input nitrogen for the Amazon river prawn monoculture (~58%; ~199 mg N/m 2 day −1 ) and the second highest identified input for the tambaqui monoculture (~42% ~168 mg N/m 2 day −1 ) and the IMTA (~23%; ~114 mg N/m 2 day −1 ). Reported inlet‐water contributions at the same facility with the same water source were ~30% for the IMTA of the Amazon river prawn and Nile tilapia (David et al, ). The inlet‐water nitrogen for the IMTA of Indian Major Carp ( Labeo rohita ) and Giant river prawn ( M. rosenbergii ) contributed less than 0.5% of all nitrogen inputs (Sahu, Adhikari, Mahapatra, & Dey, ), and in Giant river prawn monoculture 0.5%–0.6% of all inputs (Adhikari, Sahu, Mahapatra, & Dey, ; Sahu, Adhikari, Mahapatra, & Dey, ), all experiments being carried out in earthen ponds and with the use of clean freshwater and fertilizers.…”

“…Feed nitrogen has accounted for ~95%–97% of all inputs for the semi‐intensive grow‐out of the Giant river prawn (Adhikari et al, ; Sahu et al, ), ~88% for Channel catfish ( Ictalurus punctatus ) monoculture (Gross et al, ), 91% for Nile tilapia monoculture (Acosta‐Nassar, Morell, & Corredor, ), and 97% for tambaqui monoculture (Jiménez‐Montealegre et al, ). In the IMTA of the Amazon river prawn and the Nile tilapia, feed accounted for ~ 65%–71% of all nitrogen inputs (David et al, ). In the present study, feed nitrogen represented ~29%–46% of all inputs for the two monocultures (~91–184 mg N/m 2 day ‐1 ) and the IMTA (~144 mg N/m 2 day ‐1 ).…”

“…The nitrogen concentration of the settleable solids (SS) was used to determine the nitrogen content of the TSS, which was then multiplied by the pond volume to determine the nitrogen accumulated as TSS. Tripton samplers were used to quantify settleable solids biweekly using a methodology modified from David, Proença, and Valenti (, ). Each tripton sampler consisted of six 1.876‐L PVC tubes, 9.7 cm in diameter and 25.4 cm long, with a total area of 0.045 m 2 .…”