Performance and operation of a rotating biological contactor in a tilapia recirculating aquaculture system

This paper describes the performance characteristics of an industrial-scale air-driven rotating biological contactor (RBC) installed in a recirculating aquaculture system (RAS) rearing tilapia at 28 °C. This three-staged RBC system was configured with stages 1 and 2 possessing approximately the same total surface area and stage 3 having approximately 25% smaller. The total surface area provided by the RBC equaled 13,380 m². Ammonia removal efficiency averaged 31.5% per pass for all systems examined, which equated to an average (± standard deviation) total ammonia nitrogen (TAN) areal removal rate of 0.43 ± 0.16 g/m²/day. First-order ammonia removal rate (K₁) constants for stages 1–3 were 2.4, 1.5, and 3.0 h⁻¹, respectively. The nitrite first-order rate constants (K₂) were higher, averaging 16.2 h⁻¹ for stage 1, 7.7 h⁻¹ for stage 2, and 9.0 h⁻¹ stage 3. Dissolved organic carbon (DOC) levels decreased an averaged 6.6% per pass across the RBC. Concurrently, increasing influent DOC concentrations decreased ammonia removal efficiency. With respect to dissolved gas conditioning, the RBC system reduced carbon dioxide concentrations approximately 39% as the water flowed through the vessel. The cumulative feed burden – describes the mass of food delivered to the system per unit volume of freshwater added to the system daily – ranged between 5.5 and 7.3 kg feed/m³ of freshwater; however, there was no detectable relationship between the feed loading rate and ammonia oxidation performance.     

Design and performance of a recirculating aquaculture system for oyster larval culture

The major objective of this study was to introduce a newly designed recirculating aquaculture system (RAS) for oyster (Crassostrea angulata) larval culture. The system includes a culture tank, a suspended circular inlet‐pipe, an upwelling aeration pipe, combined “banjo” sieves and a bioreactor chamber containing microalgae life keeping installation. The system was designed to resolve three problems: (i) stranding of larvae caused by water level changes and aeration, (ii) physical clogging of the screens and also (iii) deterioration of diet microalgae. The culture tank, “banjo” sieve size, water flow rate and light intensity for maintaining microalgae activity were all designed according to the pattern of larval movement and feeding behaviour. Results of this study showed the best average SGR for larval length was 6.36%/d (9.5 μm/d) and survival rate was 80%, with initial rearing density of 50 larvae/ml, indicating the problems above were fully resolved. Consequently, the system is fit for larval culture in mass production of oysters.     

Use of an internal fibrous biofilter for intermittent nitrification and denitrification treatments in a zero-discharge shrimp culture tank

To achieve water reuse in recirculating aquaculture systems, intermittent nitrification and denitrification processes using internal fibrous media was proposed. A pre-acclimated Biocord biofilter, with an initial nitrification rate of 17.1 ± 12.4 mg total ammonia nitrogen-N/m²/d was applied in a marine whiteleg shrimp (Litopenaeus vannamei) culture tank. Throughout the experiment, the aerobic nitrification activity of the biofilter was sufficient to control the ammonia and nitrite levels below 0.2 mg-N/L with an accumulation of nitrate up to 50 mg-N/L. The remaining nitrate was successfully removed after shrimp harvest with the same biofilter through anoxic denitrification in conjunction with a methanol supplement at a chemical oxygen demand: nitrate-N ratio of 5:1. With complete nitrogen removal, the water was re-aerated and the next crop of shrimp culture was initiated. In this study, a two-crop shrimp cultivation was performed in sequence in the same tank without water exchange. The microbial diversity was monitored using high-throughput sequencing on Illumina MiSeq, which demonstrated that Proteobacteria (45.3 %), Chloroflexi (18.4 %), and Bacteroidetes (17.1 %) were the most abundant phyla. With an emphasis on nitrogen removal, the family Nitrosomonadaceae and Nitrospiraceae were the dominant nitrifying bacteria during the aerobic nitrification, while a high relative abundance of the Methylophaga and Methylotenera genera was observed under the anoxic condition.     

Application of nitrification and denitrification processes in a direct water reuse system for pacific white shrimp farmed in biofloc system

The aim of the present study was to propose a low-cost nitrogen removal system through the nitrification / denitrification process in order to maintain the water quality required for the Pacific white shrimp superintensive cultivation in closed systems without water renewal. The increase in productivity consequently causes the accumulation of organic matter and nitrogenous compounds, especially ammonia nitrogen and nitrite, which in high concentrations can be lethal to aquatic organisms. In addition, the accumulation of solids in the system provides conditions for the emergence of opportunistic pathogens, microalgae booms, and increases the producer's cost of inputs to maintain the equilibrium physicochemical relationships required for shrimp farming. The experimental productive cycle lasted 36 days using Litopenaeus vannamei shrimps with 7.1 g ± 0.56 g and density of 350 shrimps m⁻³. The nitrogen removal efficiency observed during the study period was 71.3 ± 5.3 %, and the shrimp had a survival of 92.9 % and a final weight of 13.1 ± 1.4 g. Thus, we established a system (ammonia and nitrite), capable of managing solids without interaction with the sea, ensuring high biosecurity against exogenous diseases in marine shrimps farms.     

Practical applications of low-pressure hydrocyclone (LPH) for feed waste and fecal solid removal in a recirculating aquaculture system

In this work, the practical application of a low-pressure hydrocyclone was examined for feed waste and fecal solid removal for common carp (27 ± 3.1 g, average ± SD) and Nile tilapia (33 ± 3.4 g, average ± SD) in a recirculating aquaculture system. The dimensions of the low-pressure hydrocyclone included an inflow diameter of 30 mm, a cylinder length of 575 mm, an overflow diameter of 60 mm, an underflow diameter of 50 mm, a cylinder diameter of 335 mm and a cone angle of 68°. The different operating conditions tested were inflow rates of 400, 600, 800 and 1000 ml s⁻¹, and underflow rates of 25%, 25%, 20% and 10% of the inflow rates, respectively. Feed waste totals of 4.1 to 4.8% and 3.6 to 4.0% of the feed intake were produced by the common carp and Nile tilapia, respectively. The maximum separation efficiency (Et) for the feed waste from the common carp was 71% at an inflow rate of 600 ml s⁻¹ with an underflow rate of 25% of the inflow rate. The maximum separation efficiency for the feed waste from the tilapia was 59% at an inflow rate of 400 ml s⁻¹ with an underflow rate of 25% of the inflow rate. The fecal solid production estimated from the digestibility was 37.9% and 35.7% of the feed intake for the common carp and Nile tilapia, respectively. The maximum separation efficiency for the feces from the common carp was 60% for an inflow rate of 600 ml s⁻¹ and an underflow rate of 25% of the inflow rate. The maximum separation efficiency for the tilapia feces was 63% at an inflow of 400 ml s⁻¹ with an underflow rate of 25% of the inflow rate. The low-pressure hydrocyclone can be adopted for prefiltration and/or post-filtration for the removal of various sized solids. Furthermore, the solids separated from the underflow can be easily removed for further processing.     

Water quality and rainbow trout performance in a Danish Model Farm recirculating system: Comparison with a flow through system

The objective was to compare water quality and fish growth and mortality in a pilot scale recirculating system (RS) and a control tank in flow through system (FTS). The RS was designed after the Danish Model Trout Farm and operated with a make up water renewal rate of 9 m³ kg^-1 of fish produced. RS water quality did not decrease significantly with water flow rate decrease in the RS. During the experiment, the RS water treatment system presented solids removal efficiency of 59.6 ± 27.7% d⁻¹, ammonia oxidation of 45 ± 32 g m⁻³ d⁻¹, oxygenation yield of 392 ± 132 g of O₂ kWh⁻¹ and CO₂ degassing of 23.3 ± 11.9% pass⁻¹. In the RS, nitrite concentration was 0.15 ± 0.07 mg l⁻¹, close to the toxicity threshold; a N₂ supersaturation phenomenon was measured, probably due to the air injection depth. The biofilter and sedimentation area management has to be improved to avoid organic matter decomposition and release of dissolved elements. Even if no N₂ over-saturation apparent effect on fish performance and aspect were detected, the airlift depth has to be modified in the case of industrial development of the RS. Some improvements of the water treatment system, especially on the airlift and sedimentation area, are suggested.Concerning fish growth, no significant differences were observed between the RS and the FTS. No pathologies were detected and cumulative mortality rates (0.1%) were similar to the farm's usual data. There were no significant effects of water flow rate decrease in the RS on fish performance and energy savings were recorded to be 0.7 kWh kg⁻¹ of fish produced between RS₁ and RS₂. The global energy cost of the RS was 3.56 kWh kg⁻¹ of fish produced (0.107 € kg⁻¹ of fish produced). Even if the energy consumption of the water treatment system can be improved, the results confirm that recirculating system can be used for industrial trout on growing, without fish performance deterioration.     

Particulate matter dynamics and transformations in a recirculating aquaculture system: application of stable isotope tracers in seabass rearing

The control of adverse effects and the possibility of removing suspended solids from recirculating aquaculture systems (RAS) are the principal challenges facing aquaculture engineers. However, their dynamics and transformations are not yet well known. In this study, carbon and nitrogen stable isotopes values (δ¹³C and δ¹⁵N) were used as tracers of particulate matter in a seabass RAS. An isotopic mixing model was employed to estimate the contributions of particulate sources. Feed (−22.1‰ for δ¹³C and 11.9‰ for δ¹⁵N), feces (−24.0‰ for δ¹³C and 6.4‰ for δ¹⁵N) and biofilm (−25.1‰ for δ¹³C and 12.9‰ for δ¹⁵N) were identified as main sources of particulate matter. The particle traps collected a mixing of 29% of uneaten feed and 71% of feces, when drum filter eliminated all remaining uneaten feed, shifting the isotopic signatures of suspended solids from −23.8 and 7.9‰ to −24.9 and 8.3‰ for δ¹³C and δ¹⁵N, respectively. The fish muscle (−18.6‰ for δ¹³C and 15.4‰ for δ¹⁵N) could reflect the isotopic variability of feed ingredients accumulated over time. The isotopic shifts indicate that the contribution of three sources depends on: (1) fish metabolism; (2) water treatment devices; and (3) bacterial bio-fouling into biofilter.     

墨瑞鳕循环水养殖系统中不同生物膜反应器水处理效率及微生物群落对比分析

固定床生物膜反应器(fixed-bed biofilm bioreactor, FBBR)和移动床生物膜反应器(moving- bed biofilm reactor, MBBR)在养殖水体氨氮(NH4+-N)和亚硝酸氮(NO2–-N)污染控制中已有较为广泛的研究,然而相关研究大多是在实验室完成的,目前尚缺乏实际生产的循环水养殖系统(recirculating aquaculture system, RAS)中FBBR和MBBR水体净化效能的对比研究。因此,本研究将FBBR (弹性毛刷滤料)和MBBR (PVC多孔环滤料)并联接入实际生产的墨瑞鳕(Macculochella peeli) RAS中,实现二者的同步连续运行(35 d),考察了其出水水质变化和微生物群落结构。出水水质变化表明,FBBR和MBBR中氨氧化能力的形成快于亚硝氮氧化能力,硝化能力渐趋成熟,可以有效控制养殖水体中的NH4+-N和NO2–-N浓度,但会导致养殖水体中硝酸氮(NO3–-N)积累和pH下降;单因素方差分析表明,FBBR出水中NH4+-N、NO2–-N、NO3–-N浓度和pH与MBBR出水无显著差异,两反应器的硝化效率相似。FBBR和MBBR在微生物群落上的相同点在于：优势菌门为变形菌门(Proteobacteria) (相对丰度分别为69.42%和86.92%),优势菌纲为γ-变形菌纲(γ-Proteobacteria) (40.71%和63.36%)和α-变形菌纲(α-Proteobacteria) (26.58%和21.74%),优势菌属为不动杆菌属(Acinetobacter) (27.50%和53.29%);硝化菌由亚硝化单胞菌属(Nitrosomonas)和硝化螺菌属(Nitrospira)构成;硝化螺菌属的相对丰度远高于亚硝化单胞菌属,两反应器中可能存在完全氨氧化菌。两反应器在微生物群落上的不同点在于FBBR微生物群落的丰富度和多样性以及硝化菌的相对丰度均高于MBBR。本研究可以为RAS养殖水体净化提供技术支撑,助推循环水养殖模式的推广应用。     

Growth, stress tolerance and non-specific immune response of Japanese flounder Paralichthys olivaceus to probiotics in a closed recirculating system

ABSTRACT:   Effects of probiotics on growth, stress tolerance and non-specific immune response in Japanese flounder Paralichthys olivaceus were evaluated in a closed recirculating system. Survival and growth of flounder treated by supplying commercial probiotics either in the diet (the probiotic diet group), or into the rearing water (the water supply group), were higher compared to the untreated group (the control group). Water quality parameters, pH, NH₄-N, NO₂-N and PO₄-P showed lower concentration in the probiotic diet group compared with the control group and the supply group. Plasma lysozyme activity in the probiotic diet group and the water supply group was significantly higher ( P  < 0.05) than that in the control group. In heat shock stress tests, flounder in the probiotics-treated groups showed greater heat tolerance (measured by 50% lethal time, LT50) than the control group. Pathogen challenge tests with Vibrio anguillarum (2 × 10⁷ c.f.u./mL) resulted in significantly higher survival in the probiotics-treated groups than the control group. Results indicated that probiotics supplied in the rearing water and the diet of fish enhanced the stress tolerance and the non-specific immune system of Japanese flounder, providing them a higher resistance against stress conditions and pathogens.     

Effect of peracetic acid on levels of geosmin, 2-methylisoborneol,and their potential producers in a recirculating aquaculture system for rearing rainbow trout (Oncorhynchus mykiss)

In recirculating aquaculture systems (RAS)s, off-flavors and odors, mainly caused by geosmin (GSM) and 2-methylisoborneol (MIB), can accumulate in the flesh of fish from RAS water, reducing the profitability of production. In this study, peracetic acid (PAA) was applied in three application intervals to pump sumps of rainbow trout (Oncorhynchus mykiss) reared in RAS. Using a real-time polymerase chain reaction (qPCR), the potential off-flavor producers were quantified using geoA and MIB synthase genes. Streptomyces was identified as the major GSM producer, and biofilters showed the highest number of potential off-flavor producers. Concentrations of GSM and MIB were analyzed in the circulating water and in the lateral part of the fish fillet. In water, concentrations up to 51 ng L⁻¹ (GSM) and 60.3 ng L⁻¹ (MIB) were found, while in the fillet, these were up to 9.8 ng g⁻¹ (GSM) and 10.2 ng g⁻¹ (MIB), decreasing with increasing number of PAA applications. PAA applications reduced the levels of off-flavor compounds, although this was insufficient to fully prevent the accumulation of GSM and MIB.     

Effects of water exchange regimes on growth, survival and shell normality of the hatchery reared juvenile spotted babylon (Babylonia areolata Link 1807) in a recirculating seawater system

Growth, survival and shell normality of hatchery reared juvenile Babylonia areolata were examined at four water exchange regimes of 0, 15, 30 and 60 day intervals in a recirculating seawater system over a 120 day experimental period. Higher body weight gains and shell length increments were observed in snails held at water exchange of 15 day intervals, especially when compared with those held at water exchange of 60 and 0 day intervals (P < 0.05). Water exchange affected the final survival of B. areolata. At the end of the experiment, final survival rates were 65.47 ± 0.66%, 87.48 ± 0.67%, 86.34 ± 0.92% and 78.50 ± 3.26% for snails held in the water exchange treatments of 0, 15, 30, and 60 day intervals, respectively, and those of shell abnormality were 97.65 ± 1.04%, 93.09 ± 2.34%, 97.08 ± 1.18% and 96.71 ± 1.84%, respectively. The present study concluded that water exchange regimes of the recirculating system influenced growth, survival, shell normality and water quality of the recirculating culture system for this species.     

Rearing cuttings of the soft coral Sarcophyton glaucum (Octocorallia,Alcyonacea): towards mass production in a closed seawater system

The octcoral Sarcophyton glaucum has a wide Indo‐Pacific distribution and is known for its diverse content of natural products. The aim of the current study was to establish a protocol for rearing miniature cuttings of S. glaucum in a closed seawater system. In order to determine the optimal conditions for rearing, the survival, average dry weight, percentage of organic weight and development of the cuttings were monitored under different temperature, light, salinity and feeding regimes. At 26 °C, the highest dry weight was obtained, and at 20 °C, the highest percentage of organic weight. The dry weight of the cuttings increased with the light intensity, while under 35–130 μE m^?2 s^?1, survival was high. Salinity did not affect any of the colonies' features. Feeding intervals of 7 and 30 days yielded a better result than of 2 days. A comparison of the colonies derived from the closed system with the colonies reared in a flow‐through system, those reared in the sea and with field‐collected colonies revealed the importance of environmental conditions in determining the features of the colonies. The study emphasizes the advantages of a closed seawater system in controlling the conditions needed for rearing cuttings of S. glaucum for targeted farming.     

The integrated culture of seaweed, abalone, fish and clams in modular intensive land-based systems: II. Performance and nitrogen partitioning within an abalone (Haliotis tuberculata) and macroalgae culture system

A pilot-scale system for the intensive land-based culture of abalone was established using an integrated design aimed at eliminating the dependence on external food sources, whilst reducing water requirements and nutrient discharge levels. The system was the first and simplest trial in a series of progressive complexity of the concept of integrated culture of seaweed, abalone, fish and clams in modular and intensive land-based facilities. Relative sizes of the modules, their stocking densities and the rate of nutrient supply were determined based on earlier results to be optimal. Effluents from two abalone (Haliotis tuberculata) culture tanks drained into macroalgae (Ulva lactuca or Gracilaria conferta) culture and biofilter tanks, where nitrogenous waste products contributed to the nutrition of the algae; net algal production from each algal tank was harvested and used to provide a mixed diet for the abalone. Excess algal yield was used elsewhere. The system was monitored to assess productivity and nitrogen partitioning over a year, while improvements were made based on the accumulating results. Total annual N-budgets were combined with mean production figures to determine a suitable ratio of abalone biomass to algal culture vessel productivity, towards commercial application of the concept. The abalone grew on average 0.26% and 0.25% body weight/d in the two culture tanks; reduced growth and increased food conversion ratios (food eaten/biomass gain; w/w) were associated with high summer water temperatures (max. 26.9°C). U. lactuca showed reliable growth and filtration performance (mean production of 230 g fresh weight/m²/d, removing on average 58% of nitrogen supplied). Conversely, G. conferta growth was highly erratic and was deemed unsuitable for the current application. It is estimated that 1 kg of abalone biomass would require food supplied by 0.3 m² of U. lactuca culture, reducing N inputs required by 20% and N in effluent by 34% when compared to the two organisms grown in monoculture.     

The performance and impact of a bubble-wash bead filter in a recirculating green water larval culture system for delta smelt (Hypomesus transpacificus)

Delta smelt are cultured at the UC Davis Fish Conservation and Culture Lab (FCCL) for research purposes. The culture systems used are based on recirculation technology to ensure optimum water quality for the fish at each life stage. Larval culture takes place in recirculation systems with green water to which a Nannochloropsis algal concentrate is added to maintain a turbidity of approximately 9 NTU. A bubble-wash bead filter is used to remove total suspended solids (TSS) from the recirculation system. The performance of the bubble-wash bead filter has been evaluated by testing the TSS and particle size distribution in two parallel systems operated in the same way. The need for bubble-wash bead filter backwashing and the impact of the backwash method were evaluated also.The results show that the bubble-wash bead filter removed a great deal of the TSS, including the algae added to maintain the turbidity. An improper backwash method could result in a short term but significantly high TSS peak in the system immediately after the backwash event. Testing over an extended filtration period with a prolonged backwash interval showed that the TSS in the system remained stable up to 150 h post backwash, at which time it increased rapidly. The TSS accumulation in the system with a bubble-wash bead filter that was not backwashed was greater than that in a parallel system without a bubble-wash bead filter. No significant mortality increase was found in the system without a bubble-wash bead filter for 34 days, which provides a possible alternative in order to lower the rearing cost. Nevertheless, there are benefits of using a bead filter, and these are discussed in the paper.     

Performance characteristics of fluidised bed biofilters in a novel laboratory-scale recirculation system for rainbow trout: nitrification rates, oxygen consumption and sludge collection

A laboratory-scale recirculating aquaculture system for fluidised bed biofilter evaluation was engineered. The design included all components found in typical full-scale commercial production systems. The system included two identical units each with oxygenation, UV treatment, cooling, biofiltration and a particulates separation device. Water from the two systems was mixed in a degassing unit. A 1 month test period after biofilter maturation revealed stable concentrations of total ammonia nitrogen (TAN), nitrite and nitrate within the system. Mean nitrification rate was 0.27 and 0.21 g TAN m⁻² day⁻¹. Oxygen consumption in the biofilters ranged between 56 and 64% due to nitrifying activity. Mass balances on nitrogen indicated that 48%, added via the feed, was converted to nitrate within the system, with 6% of the added nitrogen being found in the sludge. The remaining 43% was either used during fish growth, left the system, as organic nitrogenous compounds (or unidentified nitrogenous compounds), via the outlet, or was lost to the atmosphere. At least 61% of the nitrate produced was generated by the biofilters. The system proved to be an exceptional set-up for evaluation of the performance of fluidised bed biofilters, allowing both pre- and post-filter measurements of various water quality criteria.     

Effect of dietary protein level on growth, survival and ammonia efflux rate of Litopenaeus vannamei (Boone) raised in a zero water exchange culture system

Litopenaeus vannamei postlarvae (1.96±0.07 g) were reared in a zero water exchange system for 25 days at 28°C. They were fed four commercial diets containing 25%, 30%, 35% or 40% crude protein in three replicate aquaria per dietary treatment. Total ammonia, nitrite, nitrate and pH were monitored weekly and total ammonia levels were additionally measured every 3 days using the flow injection analysis method. Total ammonia efflux rates were measured at days 0, 14 and 21, and survival and growth rates were recorded at the end of the experiment. No significant differences between water quality parameters such as temperature, salinity, dissolved oxygen and pH were found. Nitrite concentration remained low in all dietary treatments up to the second week increasing considerably from day 14 onwards suggesting the initiation of the nitrification process. Water total ammonia of all experimental groups exhibited a gradual increase up to day 13; however, following this time ammonia levels of all experimental groups decreased, probably due to either the action of bacterial nitrification or ammonia‐N uptake by the animals. High ammonia efflux rates were recorded at day 14, especially after the first hour of immersion in the 25% protein group, but no significant changes occurred in any experimental group after 3 h. No significant differences in weight gain, final weight or survival of shrimp were observed under these experimental conditions. The importance of zero water exchange systems and their effects on the nitrogen metabolism of crustaceans are discussed.     

Performance of plastic biofilter media with different configuration in a water recirculation system for the culture of Nile tilapia (Oreochromis niloticus)

Three kinds of locally available plastic biofilter media with different configurations (plastic rolls, PVC pipes and scrub pads) were evaluated for their efficiency in organic waste removal from the effluents of an intensive recirculating tilapia culture system. A set of three types of solid-removing filters consisting of screened sedimentation; upflow sand as well as plastic bead filtration accomplished the mechanical filtration. Values of critical metabolic wastes like total ammonia nitrogen (TAN) (0.92 ppm) and nitrite-nitrogen (NO₂-N) (0.22 ppm) were found to be well within the acceptable limits, while other water quality parameters in the culture water were also maintained within the normal range by the filtration system. Removal rates of 3.46 g TAN/m³ per day and 0.77 g NO₂-N/m³ per day, as well as TAN and NO₂-N removal efficiencies of 29.37 and 27.3% respectively, were established to be the best for the plastic-roll biofilter medium as compared to PVC-pipe and scrub-pad media. Percent removal of TAN and NO₂-N per pass of the biofilter (25.49 and 26.3% respectively) and the specific TAN and NO₂-N removal rates (43 and 9.6 mg/m² per day) of plastic rolls were also found to be superior to the other two biofilter media. Pieces of PVC pipes as biofilter medium is recommended to be used in the biofilters in view of their cheaper cost.     

Performance of a photo‐heterotrophic,hypersaline system for intensive cultivation of white leg shrimp (Litopenaeus vannamei) with minimal water replacement in lined ponds using a stochastic approach

The aim of the study was to evaluate the performance of Litopenaeus vannamei in an intensive photo‐heterotrophic hypersaline system with minimal seawater replacement, and establish relationships between parameters of a stochastic production model and relevant water quality variables. Six experimental 1000 m² lined ponds were stocked at a density of 120 shrimp m^?2 for a 105‐day trial. Salinity increased from 37 to 45 ± 2 g/L, and the water level was maintained with the weekly addition of filtered seawater, equivalent to 1.6% per day. The stochastic model predicted that, at harvest, there is 95% confidence that the system produces between 12.1 and 14.7 t/ha with a mean final individual weight of 13.1 g and a mean survival of 84.2%. Sensitivity analyses showed that dissolved oxygen and individual final weight of shrimp were the main variables influencing yield variance. Nitrogenous compounds were maintained between optimal cultivation levels (NH₃–NH₄⁺ = 0.73 ± 0.43 mg/L, N–NO₂^? = 0.09 ± 0.05 mg/L, N–NO₃^? = 3.22 ± 0.11 mg/L). Heterotrophic bacteria (6.6 ± 3.4 × 10⁵ CFU/ml) and chlorophyll‐α concentration (108.5 ± 80.2 μg/L) showed a similar development pattern, indicating a strong relationship between bacteria and microalgae during cultivation. Vibrio spp. concentrations were low (1.24 ± 1.42 × 10³ CFU/ml). It was shown that the photo‐heterotrophic system could be used in hypersaline conditions, typical of semi‐arid regions, to consistently produce between 12.1 and 14.7 t/ha in 15 weeks.