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Field trial evaluation of sensor-based aquaculture automation for improved biofloc shrimp culture
... Deb et al. primarily address the topic of water quality control inside biofloc systems [13]. Sasikumar, R., et al. measured the pH and oxygen quality of pond water in a biofloc system [14]. Podder, Saurov, et al. focus on temperature, dissolved oxygen, pH, water level, and turbidity. ...
Biofloc technology mitigates aquaculture’s environmental impact by using microbial flocs to convert organic waste into nutrient rich feed. To enhance water quality management, our research focuses on a GSM based monitoring system for real time data collection and analysis. The system integrates pH, temperature, and ultrasonic sensors with an Arduino Uno microcontroller, GSM module, servo, and pump motors to monitor and regulate water quality. The system measures timely and crucial data on water quality, including parameters such as temperature, pH levels, and the state of the feeding box. The pH and temperature sensors provide analog readings, while the ultrasonic sensor monitors feeding box levels. Food management is controlled by a servo motor that operates the feeding box, and a pump motor maintains water quality. The system uses temperature and pH sensors for rapid hazard detection, minimizing ammonia and nitrite buildup risks. The GSM module enables real time data connectivity, allowing users to track and control system operations remotely. This study empowers fish farmers and hobbyists with real time water quality data, promoting informed decision-making to enhance aquatic health and productivity. It offers valuable insights to the broader aquaculture community.
An aquaculture automation system (AcAS) is a user-friendly single-window unit. This allows end users to monitor and control the entire system easily through a built-in, customizable graphical user interface. AcAS was designed for simplicity, making it easy to configure and use. This system was integrated with highly efficient industrial-grade environmental sensors (pH, conductivity, oxidation-reduction potential, and dissolved oxygen) to ensure precise and error-free results in harsh environments. It can also store user and system data in an built-in memory device. It is equipped with built-in Wi-Fi, LoRa/ZigBee, and 4G/5G modules for data transfer, making it compatible with modern communication technologies. The program was programmed to be farmer-friendly and helped farmers maintain optimal shrimp growth conditions by monitoring various parameters. AcAS takes corrective measures as required, and provides updates to farmers through a graphical display unit. Farmers can also configure devices to receive alerts for important field parameters or alarm conditions. Therefore, AcAS enhances the efficiency and sustainability of aquaculture farming by enabling precise control of farming conditions and proactive management of aquaculture.
The development of nano-enabled fertilizers presents new opportunities to improve crop nutrient use efficiency and reduce environmental impacts of agriculture. Nanoparticles, nano capsules, and nano clays can be engineered to control the release rate of nutrients to better match crop demands over time. Slow-release nano fertilizers may enhance nutrient absorption by plants while mitigating nutrient losses to the environment. Additionally, nano fertilizers can facilitate co-delivery of nutrients, growth regulators, and pesticides, allowing for more precise crop management practices. This review synthesizes current research on synthesis techniques, characterization methods, and agronomic testing results for a range of nano fertilizer products. Key nutrient carriers reviewed include mesoporous silica nanoparticles, layered double hydroxides, cellulose nanocrystals, and halloysite nanotubes loaded with nitrogen, phosphorus, potassium, and micronutrients. Release kinetics depend on nano fertilizer composition, size, and shape, as well as environmental conditions. Field studies indicate positive impacts of nano fertilizers on crop yield, nutrient use efficiency, and pest resistance compared to conventional fertilizer formulations. However, questions remain regarding large-scale feasibility, economic viability, environmental fate, and biological impacts of nano-enabled fertilizers. Ongoing interdisciplinary research across the domains of materials science, agronomy, ecology, and economics is required to develop nano fertilizers that maximize production efficiency while minimizing risks.
Traditional commercial media are costly and not ideal for large-scale probiotic production in aquaculture. Choosing the right carbon source for probiotic growth and understanding how biomass production works can offer valuable insights for potential use in aquaculture. In this study, we tested 12 starchy extracts as potential cost-effective alternatives to supplement the culture media for the production of biofloc-based probiotic isolates. We cultured probiotic strains obtained from shrimp biofloc farms and assessed their growth density and cell viability. We isolated and identified probiotic strains that were likely to be Lactobacillus sp., Bacillus sp., Pseudomonas sp., and Saccharomyces sp. Of all the starchy extracts tested, the fermented rice extract proved to be an effective carbon source for boosting cell density, viability, and metabolic activity. We also experimented with fermented rice extracts in a lab-scale bioreactor for biomass production of these isolates. In this experiment, all the strains showed an increase in cell density over time. Pseudomonas sp. exhibited the fastest growth rate, followed by Saccharomyces sp., Lactobacillus sp., and Bacillus sp. The results of this study revealed that newly formulated culture medium not only reduced production costs but also boosted biomass production and cell viability of these isolates. This straightforward and practical process improves the biomass yield and probiotic effectiveness, which could potentially benefit the aquaculture industry.
Biofloc Technology (BFT) is proven to be the fulcrum of sustainable recirculating aquaculture system especially under zero water discharge condition. The efficiency of BFT system is reinforced by an unswerving microbial community in the system. Several researchers have made copious reports on the microorganisms in BFT and identified heterotrophic bacteria predominant in the microbial composition. A summary of these researches considers these microorganisms playing the role of chemo-photosynthetic autotrophs, organic detoxifiers, probiotic, decomposers/bioflocculants, bio-leachers and pathogens. Although these functional roles are well identified, the reports have failed to sufficiently illustrate the borderline at which these microbial communities fail to serve their beneficial roles in BFT system. This review paper firstly presents a snapshot of some indispensable water quality conditions and zootechnical variables aided by the microbial community in floc as well as the amphibolic process that synthesizes nutrient from the organic deposit in BFT. Furthermore, information on the microbial community in BFT is evaluated to have Bacillus sp., Lecane sp. and Pseudomonas sp. serving all-encompassing role in BFT while Vibrio sp. and Enterobacter sp. are pathogenic under unsuitable water quality conditions. Functional characterisation of the commonly reported microorganisms in BFT categorised 21.95 % as most critical, whose abundance indicates an efficient BFT.
Aquaculture is a crucial industry that can help meet the increasing demand for aquatic protein products and provide employment opportunities in coastal areas and beyond. If incorrectly manage, traditional aquaculture methods can have negative impacts on the environment and natural resources, including water pollution and overuse of wild fish stocks as aquafeed ingredients. Biofloc technology (BFT) may offer a promising solution to some of these challenges by promoting a cleaner and sustainable production system. BFT converts waste into bioflocs, which serve as a natural food source for fish and shrimp within the culture system, reducing the need for external inputs, such as feed and chemicals. Moreover, BFT has the potential to improve yields and economic performance while promoting efficient resource utilization, such as water and energy. Despite its numerous advantages, BFT presents several challenges, such as high energy demand, high initial/running costs, waste (effluent, suspended solids, and sludge) management, opportunistic pathogens (vibrio) spread, and a lack of understanding of operational/aquatic/microbial dynamics. However, with further training, research, and innovation, these challenges can be overcome, and BFT can become a more widely understood and adopted technique, acting as an effective method for sustainable aquaculture. In summary, BFT offers a cleaner production option that promotes circularity practices while enhancing performance and economic benefits. This technique has the potential to address several challenges faced by the aquaculture industry while ensuring its continued growth and protecting the environment. A more broad BFT adoption can contribute to meeting the increasing demand for aquaculture products while reducing the industry’s negative impact on the environment and natural resources. In this context, this review provides an overview of the advantages and challenges of BFT and highlights key technical, biological, and economic aspects to optimize its application, promote further adoption, and overcome the current challenges.
The Aquaculture industry is a sector that faces difficulties in maintaining a high-quality production of food in a sustainable way due to the technological limitations of the commercial tools and the lack of integration of systems and sensors that can monitor the environmental variables and physiological characteristics of the animals. In most aquaculture farms, human operators are still responsible for collecting data manually and over long time intervals. In this way, management and decision-making depends on the operator's experience and can be negatively affected by human subjectivity. The application of Industry 4.0 concepts to collect and store data in real time using interconnected sensors and other automated equipment allows to increase the accuracy of the farm's operation and support faster and evidence-based decisions. This work presents an overview of some Industry 4.0-based approaches used to improve the quality, productivity and sustainability of the aquaculture industry. Initially, the Industry 4.0 definition and main concepts are presented as well as the consequences of its implementation for the improvement of general industrial processes. Following that, the current scenario of the aquaculture industry in terms of global food production and the main limitations of the sector that can be supported by intelligent systems to improve results are presented. In the next sections, specific technologies such as camera systems for animal and environmental monitoring, sensing networks and IoT to collect, transmit and store data, automated devices to support some activities and monitoring tasks, tools to support data interpretation and decision-making and modern sensing strategies for hard-to-monitor parameters are detailed. This review article shows the feasibility of using the aforementioned technologies to improve results of the aquaculture industry and, due to its advantages, it is believed that its widespread use can fill the existing gaps in this field of research in the next years.
Future agricultural systems should increase productivity and sustainability of food production and supply. For this, integrated and efficient capture, management, sharing, and use of agricultural and environmental data from multiple sources is essential. However, there are challenges to understand and efficiently use different types of agricultural and environmental data from multiple sources, which differ in format and time interval. In this regard, the role of emerging technologies is considered to be significant for integrated data gathering, analyses and efficient use. In this study, a concept was developed to facilitate the full integration of digital technologies to enhance future smart and sustainable agricultural systems. The concept has been developed based on the results of a literature review and diverse experiences and expertise which enabled the identification of stat-of-the-art smart technologies, challenges and knowledge gaps. The features of the proposed solution include: data collection methodologies using smart digital tools; platforms for data handling and sharing; application of Artificial Intelligent for data integration and analysis; edge and cloud computing; application of Blockchain, decision support system; and a governance and data security system. The study identified the potential positive implications i.e. the implementation of the concept could increase data value, farm productivity, effectiveness in monitoring of farm operations and decision making, and provide innovative farm business models. The concept could contribute to an overall increase in the competitiveness, sustainability, and resilience of the agricultural sector as well as digital transformation in agriculture and rural areas. This study also provided future research direction in relation to the proposed concept. The results will benefit researchers, practitioners, developers of smart tools, and policy makers supporting the transition to smarter and more sustainable agriculture systems.
Water management is one of the crucial topics discussed in most of the international forums. Water harvesting and recycling are the major requirements to meet the global upcoming demand of the water crisis, which is prevalent. To achieve this, we need more emphasis on water management techniques that are applied across various categories of the applications. Keeping in mind the population density index, there is a dire need to implement intelligent water management mechanisms for effective distribution, conservation and to maintain the water quality standards for various purposes. The prescribed work discusses about few major areas of applications that are required for efficient water management. Those are recent trends in wastewater recycle, water distribution, rainwater harvesting and irrigation management using various Artificial Intelligence (AI) models. The data acquired for these applications are purely unique and also differs by type. Hence, there is a dire need to use a model or algorithm that can be applied to provide solutions across all these applications. Artificial Intelligence (AI) and Deep Learning (DL) techniques along with the Internet of things (IoT) framework can facilitate in designing a smart water management system for sustainable water usage from natural resources. This work surveys various water management techniques and the use of AI/DL along with the IoT network and case studies, sample statistical analysis to develop an efficient water management framework.
Microorganisms (MOs) are an important member of any aquaculture system. The MOs in the BFT (Biofloc Technology) system are also crucial, diverse and therefore have different roles. This study reviews the importance of biofloc organisms (BFOs) in BFT, the factors affecting their population compositions, the impact of BFOs on water quality, and applications as food source for cultivated aquatic species. Common MOs in the BFT system often include photoautotrophic (e.g. microalgae), chemoautotrophic (e.g. nitrifying bacteria), and heterotrophic organisms, including fungi, ciliates, protozoans, and zooplankton (e.g. rotifers, copepods, and nematodes). Various factors such as salinity, type of carbon source, carbon to nitrogen ratio, aeration, light, stocking density, and total suspended solids affect the quality, density, and diversity of BFOs. Various MOs show different functional characteristics and perform three main functions: (i) help to improve the water quality by removing inorganic nitrogen compounds (bioaccumulation, bioassimilation, nitrification, and denitrification); (ii) act as a supplementary food source, and (iii) create probiotic properties; key roles for any aquatic farming system.
The aim of this study was to investigate the effect of different levels of wet biofloc on water quality and feeding, growth performance, survival, and body composition of banana shrimp Fenneropenaeus merguiensis. The experiment consisted of the control group (feeding 100% commercial feed and 50% water exchange per day without biofloc) and four treatments in which portions of the commercial feed were replaced by wet biofloc (T2: 25%, T3: 50%, T4: 75%, and T5: 100%) with limited water exchange. Postlarvae of banana shrimp (mean ± SD weight of 4.5 ± 0.68 mg, density of 5 postlarvae/L) were experimentally held in fiberglass tanks with 170 L of seawater with salinity of 28‰ for 30 d. An acceptable range of total ammonium nitrogen and nitrite nitrogen was maintained in rearing tanks with wet biofloc throughout the experiment despite minimal water exchanges, but total ammonium nitrogen and nitrite nitrogen were significantly higher in the control group. Postlarvae fed with 25% wet biofloc had significantly higher total biomass (222.36 g) and survival (76.27%) compared with the other treatments. A comparison of banana shrimp fed with 25% or 50% wet biofloc and those fed with 100% commercial feed did not show a significant difference in body composition. The highest levels of body ash (12.7% of dry weight) were obtained in banana shrimp fed with 100% wet biofloc. In general, it was found that up to 50% of commercial feed can be replaced with wet biofloc (developed under the conditions of this study) without compromising growth performance, survival, and carcass quality of banana shrimp postlarvae.
Biofloc technology (BFT), the new "blue revolution" in aquaculture, has the potential to increase aquaculture production's sustainability without sacrificing quality. The main challenge of biofloc technology is the recycling of waste nutrients, particularly nitrogen, into microbial biomass by controlling the water property. Much work has been published since the introduction of BioFloc Technology to evaluate this system in various contexts and under various nutritional situations. This paperwork is being done on the design and development of a water quality monitoring system of a Biofloc, with the objective of notifying the user through some LED’s and display. The pH value and temperature of water in Biofloc are sensed with a pH sensor and temperature sensor respectively and will notify through LED’s. Also, an automatic feeding system is added which is controlled by sending SMS through a GSM module that controls a servo motor to open and close the food gate accordingly.
Biofloc technology (BFT) is gaining traction as a strategic aquaculture tool for boosting feed conversions, biosecurity, and wastewater recycling. The significant aspect of BFT is aquaculture with highest stocking density and minimal water exchange. It not only improves the water quality of a system by removing inorganic nitrogen from wastewater but also serves as a suitable feed supplement and probiotic source for cultured species. This technology is commonly used for shrimp and tilapia culture and can be used for both semi-intensive and intensive culture systems. Biofloc, when combined with formulated diets, forms a balanced food chain that improves growth performance. Nutrients in this system are continuously recycled and reused and form an efficient alternative system in aquaculture. In addition to the reduction in water exchange, it is also considered as a bio-security measure, since it prevents entry of disease from outside sources. Aquamimicry is an innovative concept that simulates natural estuarine conditions by developing copepods that act as supplementary nutrition especially for shrimp culture. The review highlights the process, significance, and development of BFT, its microbial interactions, nutritional value, transition from biofloc to copefloc, and concept of aquamimicry to sustainably improve aquaculture production.
Biofloc technology (BFT) is one of the most promising technologies in global aquaculture for the purpose of improving water quality, waste treatment, and disease prevention in intensive aquaculture systems. However, characterization of the microbial species and antibiotic resistance potentially present in biofloc-based aquaculture environments is needed. In this study, we used high-throughput sequencing technology to comprehensively compare the bacterial communities in mariculture ponds of Penaeus monodon (P. monodon), by testing of water, biofloc, and intestine of P. monodon. Operational taxonomic units (OTUs) cluster analysis showed that the nine samples tested divided into 45 phyla and 457 genera. Proteobacteria was the dominant bacteria in water, biofloc and prawn intestine. In biofloc and intestine, the Ruegeria (2.23–6.31%) genus represented the largest proportion of bacteria, with Marivita (14.01–20.94%) the largest group in water. Microbial functional annotation revealed that in all the samples, genes encoding metabolism were predominant. The antibiotic resistance gene annotation showed the highest absolute abundance of patB, adeF, OXA-243, and Brucella_suis_mprF from Proteobacteria. PatB (11.33–15.01%), adeF (15.79–18.16%), OXA-243 (35.65%), and Brucella_suis_mprF (10.03%) showed the highest absolute abundance of antibiotic resistance genes in water, biofloc, and intestines, respectively. These findings may greatly increase our understanding of the characteristics of the microbiota of shrimp biofloc-based aquaculture systems and the complex interactions among shrimp, ambient microflora, and environmental variables. It provides a reference basis for policy on breeding, environmental safety, and maintaining food safety in the production of P. monodon.
Due to the depleting stocks of fish in the market, there have been an increased interest in aquaculture. However, raising fishes in an Intensive Aquaculture System results on a low-quality fish or even fish kills as fishes are being cultured in artificial tanks and cage systems, not on their natural habit. This paper presents a water quality monitoring system with automatic correction to monitor and maintain vital water quality parameters essential for fish growth, such as temperature, potential hydrogen (pH) level, oxidation-reduction potential, turbidity, salinity, and dissolved oxygen to achieve optimum yield using Arduino and Raspberry Pi 3B+ through LoRaWAN IoT Protocol. The system uses sensors, microcontrollers, and a web application for acquiring and monitoring data of six different water quality parameters and are maintained in a desired level optimal for fish growth using aquarium heater, motor for sodium bicarbonate distribution, solenoid valve and water pump that serves as correcting devices. The proponents measured the system’s efficiency and reliability through monitoring two intensive aquaculture setups – controlled and conventional setup. From the data gathered, the controlled setup greatly increased efficiency, reduced the work of fish farmers, avoided fish kills, and surpassed yield quality of the conventional setup.
Smart aquaculture is nowadays one of the sustainable development trends for the aquaculture industry in intelligence and automation. Modern intelligent technologies have brought huge benefits to many fields including aquaculture to reduce labor, enhance aquaculture production, and be friendly to the environment. Machine learning is a subdivision of artificial intelligence (AI) by using trained algorithm models to recognize and learn traits from the data it watches. To date, there are several studies about applications of machine learning for smart aquaculture including measuring size, weight, grading, disease detection, and species classification. This review provides and overview of the development of smart aquaculture and intelligent technology. We summarized and collected 100 articles about machine learning in smart aquaculture from nearly 10 years about the methodology, results as well as the recent technology that should be used for development of smart aquaculture. We hope that this review will give readers interested in this field useful information.
Aquaculture has been celebrated globally and believed to usher in a viable alternative to capture fisheries. It is most welcomed especially now that the world population explosion has pushed the demand on fisheries products to worrisome limits. Shrimp farming is an area of aquaculture that has witnessed significant growth in recent years, contributing substantially to the global aquaculture production. However, intensification of shrimp aquaculture has come with unintended consequences such as wastewater management and other problems emanating from environmental impact of the wastewater. This study identified excess feed and fertilizer application, metabolite wastes, shrimp mortalities, oil spillage from farm machines, drug and chemical abuse as some of the activities contributing to wastewater generation in shrimp aquaculture farming. The impact of shrimp effluent water discharged has been observed to be socio-economic with both positive and negative dimensions. In attempt to overcome the overwhelming problems associated with shrimp effluent water and bring reassurances to its sustainability, a good number of new technological approaches have been identified including caviation, high-rate algal pond system, use of nanomaterials, biofloc technology, nanoadsorbent and polymeric nanoadsorbents. Although all have been proven to be useful, none could boast of a complete and integrated approach that considers all the technological, legal, social, environmental, public health and institutional concerns.
Globally, the shrimp farming industry faces increasing challenges and pressure to reduce the broken shrimps and maintain a healthier pond environment. Shrimps lack an adaptive immune system to combat invading pathogens due to an imbalance in beneficial gut microbiota. The use of top-dressing agents like probiotics and pond optimizes is an alternative strategy to improve the innate immune system leading produce disease-free shrimp in international markets. The cost of top-dressing agents is accounted for 20% of the production cost and therefore, the development of top-dressing automation technology is important to maintain and improve the financial and environmental viability of shrimp sustainable farming. This perspective described several sensor-based aquaculture technologies for on-farm management systems but sustainability in the aquaculture industry is not yet achieved in practice. The present technology is a new invention to reduce labor and production costs required for reducing bacterial and organic loads in Biofloc shrimp cultures. Aquaculture automation system disperses the top-dressing agents to the shrimp ponds based on the signals received from microbial and environmental sensors. Continuous monitoring of shrimp growth, mortality, immune responses, diseases, and pond water quality parameters will fetch larger profits with additional savings on labor and production costs for sustainable shrimp aquaculture in India.
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This ex situ biofloc technology has high potential to be a strategy for climate change adaptation and mitigation, which is useful for improving shrimp farming practice in the Asia Pacific region and for enhancing food security with high quality of shrimp to serve consumers worldwide.
Abstract
Shrimp is an important food source consumed worldwide. An intensive aquaculture system with overuse of feed in combination with detrimental effects from climate change are serious problems leading to mass mortality of cultured shrimp. Biofloc technology is an approach to managing water quality and controlling the disease to counter the negative side of intensive culture system; however, most of the biofloc applications are naturally formed, which could be inconsistent. In this study, we employed an established optimal ratio of microbial consortium called “ex-situ biofloc (BF)” to be used as a feed supplement in shrimp cultured in a zero-water discharged system at low salinity conditions. Three feeding groups (100%commercial pellet (C), 95%C+BF, 90%C+BF) of shrimp were cultured for six weeks. The effect of an ex-situ biofloc supplement with commercial pellet reduction showed that levels of ammonium, nitrite, nitrate and phosphate were significantly decreased in water culture. Shrimp fed with ex-situ biofloc supplement with commercial pellet reduction exhibited significantly increased shrimp weight and survival, and significantly expressed growth-related genes involving lipolysis and energy metabolism higher than those fed with 100% commercial pellet. Nutritional analysis indicated a significant increase of docosahexaenoic acid (DHA) and eicosenoic acid (C20:1) concentrations in the ex-situ biofloc supplemented shrimp. This finding revealed the potential of ex-situ biofloc to manage water quality, improve shrimp growth performance and enhance shrimp nutritional value under intensive culture at low salinity conditions. The beneficial effects of the ex-situ biofloc in shrimp culture system make it a promising alternative strategy to mitigate climate change effects leading to the sustainable production of high-quality shrimp in the future.
A very effective removal of nitrate in batch and continuous experiments was achieved by a newly biofilm-formative isolated bacterium, identified by 16S rRNA as Acinetobacter EMY. The anoxic denitrifying capabilities of Acinetobacter EMY, attached to plastic biocarriers in batch and continuous moving bed bioreactors, demonstrated up to 1.75 times higher nitrate removal compared with a bacterial suspension. The denitrification rates of nitrate (200 mg/l) in the continuous operation mode were 0.39, 0.65, 1.23, and 1.14 kg-N/m³/d, with hydraulic retention times (HRTs) of 12, 8, 4, and 2 h, respectively, whereas the batch reactor removal performance showed up to 1.49 kg-N/m³/d. To the best of our knowledge, these findings are the highest values obtained for nitrate removal in comparison to previous studies focused on the characterization of denitrifying isolates. In addition, this bacterium is able to consume all of the organic matter provided in solution together with the nitrate, without leaving any residuals of organic matter in the water. This is advantageous since nitrate removal treatments by heterotrophic bacteria usually require addition of organic matter to the system, leading to secondary pollution. The isolated bacterium therefore provides a good solution for biological treatment of nitrogen in water, particularly in treatment systems that integrate immobilized biomass in the treatment process.
The consumption awareness of people in recent years has increased, with food safety becoming more and more important. While non-toxic products can be achieved by avoiding using too much antibiotics to control growth factors in a water environment, the measurement tools for dissolved oxygen on the market are very expensive and a great economic burden to fishermen. Thus, the purpose of this study is to design more economical measurement modules and algorithms for monitoring ponds. The research collected pond data through Oxidation-Reduction Potential (ORP), pH and temperature sensors, used regression analysis to infer Dissolved Oxygen (DO) by ORP and pH, and employed a real-time pond monitoring data map to figure out pond conditions. Compared with traditional equipment, findings show our approach reduces costs by about 20%, and increases production capacity and output value.
The present study assessed the effects of different types of foods and salinity levels on water quality, growth performance, survival rate and body composition of the Pacific white shrimp, Litopenaeus vannamei, juveniles in a biofloc system. Shrimp juveniles (2.56 ± 0.33 g) were cultured for 35 days in 300 L fiberglass tanks (water volume of 180 L) with a density of 1 g L-1 in six treatments. Three sources of food (100% formulated food, mixture of 66.6% formulated diet and 33.3% wet biofloc, and 100% wet biofloc) and two levels of salinity (10 and 32 ppt) were considered in two control groups and four biofloc treatments. Water quality parameters in the biofloc treatments were significantly better than control groups (P<0.05). The highest increase in growth performance and survival rate were obtained in salinity of 32 ppt and mixed food sources. Analyzing the proximate composition of body shrimp indicate an increase in lipid and ash levels in biofloc treatments, which was more evident in the salinity of 32 ppt. In addition, the proximate analysis of shrimp body showed significant differences between biofloc treatments and control groups (P<0.05). The highest FCR was found in the treatment with salinity level of 10 ppt and fed only with floc. Overall, it was found that the artificial diet supplemented with biofloc at the salinity of 32 showed better performance in the juvenile stage of Pacific white shrimp.
Aquaculture is presented as a sustainable alternative to the consumption of wild fish, for example, reducing inputs (such as feed), optimizing outputs, and reducing pollution. Extending to the agricultural framework, in this context, different technologies are being used to diminish those environmental hazards, giving rise to the precision agriculture/aquaculture being this a management concept based on observing, measuring, and responding space/temporal variability of productions. The scope of the precision aquaculture is to apply control-engineering principles to the production, to direct farmers to a better monitoring, control, and documentation of biological processes in fish farms. The aim of this review is to show an overview (enriched by a terms mapping analysis) of the precision aquaculture engineering innovations, with some examples of commercial systems, even if most of them are not specifically addressed in the precision aquaculture framework, in terms of: computer vision for animal monitoring, environmental monitoring tools, and sensor network (i.e., wireless sensor network, and long-range), robotics, and finally data interpretation and decision tools (i.e., algorithms, Internet of Things, and Decision Support Systems). Over the Internet of Things, cyber-physical systems communicate and cooperate with each other and with humans in real-time both internally and across organizational services offered and used by participants of the value chain. To increase the production and ameliorate the fish product quality and animal welfare issues, it is becoming even more important to monitor and control the production process.
An environmental friendly technology known as Biofloc Technology (BFT) has been implemented to reduce environmental damages and to sustain production of Pacific Whiteleg shrimp, P. vannamei aquaculture industry. Since there was no intensive application of BFT being conducted in industrial scale, this study aimed to assess the impact of BFT to water quality and shrimp health. To achieve maximum growth of BFT in P. vannamei cultures, an isolated biofloc boost-up bacteria inoculum was added during each new stocking program of shrimp post-larvae (PL). Samples of water, shrimp and biofloc were collected in every ten days interval started from new stocking of shrimp PL up to harvesting periods (±100 days). Interestingly, biofloc was observed started to be formed as early as 10 days after shrimp cultivation periods, where the biofloc formation was speed up by the addition of the inoculum and thus effectively enhanced good water quality which resulted in the increasing shrimp biomass. By transferring the important knowledge of BFT to shrimp industrial scale, aggregation of microbial communities in biofloc were responsible in maintaining water quality and optimizing shrimp survival and production. Thus, knowledge on microbial composition in biofloc is deemed important for successful design and application of BFT for sustainable shrimp aquaculture industry.
Abstract A study of three feeding trials was conducted to investigate the dietary protein requirements of Pacific white shrimp (Litopenaeus vannamei) at three different growth stages. Six experimental diets were formulated to include increasing protein levels of 25, 30, 35, 40, 45, and 50% (designated as P25, P30, P35, P40, P45, and P50, respectively) for three feeding trials. The three feeding trials were conducted in different-sized shrimp at 0.65 g (trial 1), 4.80 g (trial 2), and 10.5 g (trial 3). Triplicate groups of shrimp were fed one of the experimental diets for 36, 42, and 48 days in trials 1, 2, and 3, respectively. In trial 1, the growth performance was not affected by the dietary protein levels. However, protein efficiency ratio was significantly higher in P30 diet compared to P40, P45, and P50 diets. In trial 2, growth rate was significantly higher in P35 diet than in P25 diet. In trial 3, the lowest growth performance was obtained in P25 diet which significantly differed from that of other experimental diets. Broken line analysis of growth data indicates that the optimal dietary level of crude protein is 34.5, 35.6, and 32.2% for small-, medium-, and large-sized (juvenile, sub-adult, and adult stages) Pacific white shrimp, respectively.
The shrimp sector has been one of the fastest growing agri-food systems in the last decades, but its growth has entailed negative social and environmental impacts. Sustainable intensification will require innovation in multiple elements of the shrimp production system and its value chain. We use the case of the shrimp sector in the Mekong Delta in Vietnam to explore the constraints in the transition to sustainable intensification in shrimp farming, using an analytical framework based on innovation systems thinking, i.e., an aquaculture innovation systems framework. Using this framework, we conduct a systemic diagnostic of blocking mechanisms, interrelated sets of constraints within the aquaculture sector that hinder a transition toward sustainable intensification. Our findings show that the major constraints are institutional, with limited enforcement of the regulatory framework for input quality control, disease control, and wastewater management, and a lack of coordination between government bodies to design and enforce this framework. At farm level, limited access to capital favors pond mismanagement and the use of low-quality inputs. The absence of multi-stakeholder initiatives to foster dialog between actors in the value chain constrains the response to new regulations dictated by international market demand. Because of shrimp farming’s connectivity with the wider ecosystem, sustainable intensification in shrimp farming will require collective management of water resources at the landscape level for disease and water pollution control. Ecological principles for pond management need to be promoted to farmers in order to reduce farmers’ inefficient practices and build their capacity to understand new techniques and inputs available in the Vietnamese market. Our paper demonstrates for the utility of a multi-level, multi-dimension, and multi-stakeholder aquaculture innovation systems approach to analyze and address these blocking mechanisms in the transition to sustainable intensification in shrimp farming and aquaculture more broadly.
Surface waters are likely to be contaminated by both pesticides and fertilizers. Such contamination can result in changes in community composition if there is differential toxicity to individual taxa. We conducted a fully factorial mesocosm experiment that examined the single and interactive effects of environmentally realistic concentrations of nitrate and malathion on zooplankton communities and phytoplankton productivity. Malathion significantly decreased the abundance of total zooplankton, cyclopoid copepods, copepod nauplii, and Ceriodaphnia, and increased the abundance of rotifers. Nitrate addition generally had no effect on zooplankton; however, Ceriodaphnia abundance was higher in control mesocosms than in nitrate-treated mesocosms. There was only one significant interaction between malathion and nitrate treatments: For Ceriodaphnia, the no malathion, no nitrate mesocosms had much higher abundances than all other combinations of treatments. Without nitrate addition, chl a levels were uniformly low across all malathion treatments, whereas in the presence of nitrate, there were differences among the malathion treatments. In conclusion, our results demonstrate that malathion contamination of aquatic ecosystems can result in changes in the abundance and composition of zooplankton communities. In contrast, nitrate contamination appeared to have much less potential impact on zooplankton communities, either on its own or in interaction with malathion. Our results reinforce the notion that the effects of contaminants on aquatic ecosystems can be complex and further research examining the single and interactive effects of chemical stressors is needed to more fully understand their effects.
Microalgae play a key role in the dynamics of biofloc technology aquaculture systems. Some phytoplankton groups, such as diatoms, are desired for their high nutritional value and contribution to water quality. Other groups, such as cyanobacteria, are undesired because of their low nutritional value and capacity of producing toxins. So, monitoring the phytoplankton community structure and succession is key for managing biofloc systems. However, research on phytoplankton in these systems is scarce and mostly done by microscopy. The primary objective of this research was to estimate phytoplankton community structure in shrimp biofloc system water samples, using high-performance liquid chromatography methods and CHEMTAX software. The major groups present in our system were diatoms, euglenophytes, cyanobacteria and chlorophytes, while dinoflagellates were only remarkable at the initial period. We observed a clear dominance of diatoms all along the 5 months that comprised a complete biofloc system culture. The characteristic succession of autotrophic processes by heterotrophs of the biofloc systems was observed by the reduction of net primary production. Light intensity played a key role in determining the phytoplankton composition and abundance. Algal pigment analyses using high-performance liquid chromatography and subsequent CHEMTAX analysis in water samples were useful for estimating the phytoplankton community structure in the biofloc systems. However, we found some limitations when the biofloc system was in heterotrophic mode. Under these conditions, some dinoflagellates and cyanobacteria behaved as heterotrophs and lost or decreased their biomarker pigments. So, further research is needed to increase knowledge on the accuracy of high-performance liquid chromatography/CHEMTAX under these conditions.
The Pacific whiteleg shrimp, Litopenaeus vannamei, is the most farmed aquaculture species worldwide with global production exceeding 3 million tonnes annually. Litopenaeus vannamei has been the focus of many selective breeding programs aiming to improve growth and disease resistance. However, these have been based primarily on phenotypic measurements and omit potential gains by integrating genetic selection into existing breeding programs. Such integration of genetic information has been hindered by the limited available genomic resources, background genetic parameters and knowledge on the genetic architecture of commercial traits for L. vannamei. This study describes the development of a comprehensive set of genomic gene-based resources including the identification and validation of 234,452 putative single nucleotide polymorphisms in-silico, of which 8,967 high value SNPs were incorporated into a commercially available Illumina Infinium ShrimpLD-24 v1.0 genotyping array. A framework genetic linkage map was constructed and combined with locus ordering by disequilibrium methodology to generate an integrated genetic map containing 4,817 SNPs, which spanned a total of 4552.5 cM and covered an estimated 98.12% of the genome. These gene-based genomic resources will not only be valuable for identifying regions underlying important L. vannamei traits, but also as a foundational resource in comparative and genome assembly activities.
This paper presents a versatile solution in an effort of improving the accuracy in monitoring the environmental conditions and reducing manpower for industrial households shrimp farming. A ZigBee-based wireless sensor network (WSN) was used to monitor the critical environmental conditions and all the control processes are done with the help of a series of low-power embedded MSP430 microcontrollers from Texas Instruments. This system is capable of collecting, analyzing and presenting data on a Graphical User Interface (GUI), programmed with LabVIEW. It also allows the user to get the updated sensor information online based on Google Spreadsheets application, via Internet connectivity, or at any time through the SMS gateway service and sends alert message promptly enabling user interventions when needed. Thereby the system minimizes the effects of environmental fluctuations caused by sudden changes and reduces the expended labor power of farms. Because of that, the proposed system saves the cost of hiring labor as well as the electricity usage. The design promotes a versatile, low-cost, and commercial version which will function best for small to medium sized farming operations as it does not require any refitting or reconstruction of the pond.
Background
Biofloc technology (BFT), a rearing method with little or no water exchange, is gaining popularity in aquaculture. In the water column, such systems develop conglomerates of microbes, algae and protozoa, together with detritus and dead organic particles. The intensive microbial community presents in these systems can be used as a pond water quality treatment system, and the microbial protein can serve as a feed additive. The current problem with BFT is the difficulty of controlling its bacterial community composition for both optimal water quality and optimal shrimp health. The main objective of the present study was to investigate microbial diversity of samples obtained from different culture environments (Biofloc technology and clear seawater) as well as from the intestines of shrimp reared in both environments through high-throughput sequencing technology.
Results
Analyses of the bacterial community identified in water from BFT and “clear seawater” (CW) systems (control) containing the shrimp Litopenaeus stylirostris revealed large differences in the frequency distribution of operational taxonomic units (OTUs). Four out of the five most dominant bacterial communities were different in both culture methods. Bacteria found in great abundance in BFT have two principal characteristics: the need for an organic substrate or nitrogen sources to grow and the capacity to attach to surfaces and co-aggregate. A correlation was found between bacteria groups and physicochemical and biological parameters measured in rearing tanks. Moreover, rearing-water bacterial communities influenced the microbiota of shrimp. Indeed, the biofloc environment modified the shrimp intestine microbiota, as the low level (27 %) of similarity between intestinal bacterial communities from the two treatments.
Conclusion
This study provides the first information describing the complex biofloc microbial community, which can help to understand the environment-microbiota-host relationship in this rearing system.
Study on the microscopic composition of biofloc in closed hatchery culture system was carried out to determine the interaction between the aggregation flocs in the bioremediation process for the decomposition and degradation of organic matter loaded in the shrimp culture tanks. The study was done for 105 days of culture period in zero water exchange. All of the organic loaded in the culture tanks identified comes from the shrimp feces, uneaten fed, and the decomposed macro- and microorganisms died in the culture tanks. All of the microscopic organisms in the biofloc were identified using Advance microscopes Nikon 80i. From the present study, there were abundances and high varieties of phytoplankton, zooplankton, protozoa, nematodes and algae species identified as aggregates together in the flocs accumulation. All of these microscopic organisms identified implemented the symbiotic process together for food supply, become the algae grazer, act as natural water stabilizer in regulating the nutrients in culture tank and serve as decomposer for dead organic matter in the water environment. Heterotrophic bacteria identified from Pseudomonas and Aeromonas family consumed the organic matter loaded at the bottom of culture tank and converted items through chemical process as useful protein food to be consumed back by the shrimp. Overall it can be concluded that the biofloc organisms identified really contributed as natural bioremediation agents in zero water exchange culture system to ensure the water quality in the optimal condition until the end of culture period.
This study evaluated the effects of different aeration types on water quality, shrimp growth and biofloc composition in a Litopenaeus vannamei culture. The study was conducted with three treatments: (1) PR—propeller aspirator pump aerator; (2) VP—vertical pump aerator; and (3) BL—diffused air blower. The study was performed in a greenhouse with nine 35,000-L rectangular tanks. Water quality parameters (temperature, salinity, dissolved oxygen, pH, ammonia, nitrite, nitrate, settleable and suspended solids) were measured along the 33 experimental days. Moreover, samples were collected to quantify the microorganisms present in the tanks. At the end of the study, samples of the biofloc of each tank were collected to proximal analysis. Throughout the experiment, the temperature, pH, salinity and alkalinity were maintained within the recommended levels for L. vannamei. The propeller treatment showed a concentration of total ammonia above the recommended levels and lower densities of ciliates and flagellates, most likely because of inadequate biofloc formation in this treatment. The final weight was higher in the blower and propeller treatments. However, survival was lower in the propeller treatment compared to the other treatments. The results of this study suggest that diffused air systems (air blower) improve the formation of biofloc and growth performance of L. vannamei.
Chitin is one of the natural biopolymer found abundantly in the shells of crustaceans, insects and in cell walls of fungi. In this study, we determined the effect of dietary administration of 0.5, 0.75 and 1% chitin on the immune response and disease resistance in freshwater prawn, challenged against Macrobrachium rosenbergii nodavirus (MrNV) and extra small virus (XSV). We observed a significantly enhanced immune response, indicated as higher prophenoloxidase activity and respiratory burst of hemocytes, in 0.75% chitin-diet fed prawns compared to the chitin-free-diet fed prawns. Importantly, the relative percent survival (RPS) following challenge with white muscle disease (WTD) viruses was found relatively high in M. rosenbergii fed with diet containing 0.75% chitin (63.16%), suggesting an increased resistance to disease susceptibility. These results indicate that the incorporation of chitin in prawn diet would be beneficial in stimulating the immune response and thereby developing resistance against diseases.
We have designed and presented a wireless sensor network monitoring and control system for aquaculture. The system can detect and control water quality parameters of temperature, dissolved oxygen content, pH value, and water level in real-time. The sensor nodes collect the water quality parameters and transmit them to the base station host computer through ZigBee wireless communication standard. The host computer is used for data analysis, processing and presentation using LabVIEW software platform. The water quality parameters will be sent to owners through short messages from the base station via the Global System for Mobile (GSM) module for notification. The experimental evaluation of the network performance metrics of quality of communication link, battery performance and data aggregation was presented. The experimental results show that the system has great prospect and can be used to operate in real world environment for optimum control of aquaculture environment.
According to its definition, artificial intelligence (AI) is "the future built from fragments of the past." These are applications that acquire novel solutions with practice. Artificial intelligence has been used in various disciplines, from agriculture to full industry automation. Thanks to AI, aquaculture has become a less labor-intensive industry, enabling the fisheries sector to grow quickly and triple production quickly. It can appear as any laborer at work, such as feeders, water quality monitors, harvesters, processors, etc. AI can even be employed to protect aquatic life types from extinction. AI monitors fishing activity worldwide and promotes open sea fisheries' sustainability. AI plays a significant role in combating IUU fishing. Artificial intelligence (AI) can be used in aquaculture to limit input waste and cut costs by up to 30%. As a result, AI offers total control over fish production systems at a lower maintenance and input cost. AI's integration into aquaculture has transformed the industry, enabled sustainable growth, increased productivity and cost savings while minimizing environmental impact and labor requirements. Through the application of AI technologies, aquaculture can meet the growing demand for seafood while addressing challenges such as overfishing, environmental degradation, and resource scarcity.
Fisheries play an important role in the world economy, and it contributes to the nations’ income, exports, food, nutritional security, and employment opportunities. In recent years, the capture fisheries decline due to over exploitation and illegal fishing. Aquaculture is one of the lucrative foods producing industries due to its delicious taste and high-income generation in the international market; thus, aquaculture production has increased lately with various culturing methods of culture practices. Unfortunately, in the past two decades, the aquaculture industry faces serious infectious disease problems, and it affects the production level. The traditional practices are also not effective and create so many environmental hazards for disease control. Considering the potential threat and environmental issues, it should be focused on developing alternative applications for the solution of the problems. The alternative practices have versatile characteristics like safety, efficiency, and affordability and are highly recommended in aquaculture practices to achieve higher production. In the present review, we have discussed the alternative approaches for shrimp health management for improving food production, including antimicrobial and non-specific immune-stimulating herbal and algal compounds; in silico approach for designing suitable antimicrobial drugs; antimicrobial biosurfactants from microbial sources; pre and probiotics; different generation of vaccines and its production in different expression system; chicken edible antibody production and its influences in shrimp aquaculture system; Specific Pathogen Free (SPF) shrimp; RNA interference (RNAi); Phage Therapy and Gene editing technology (CRISPR). The above-said approaches help to improve the aquatic cultivable shrimps’ health leading to improve food production.
In the present era marine biotechnologies are dominating the world of scientific research assisted by great advances in molecular biology techniques, and microbial community analysis provides useful tool to investigate their diversity and their potential for biotechnological applications. In fact, several marine organisms harbor diverse microbial associated communities, which play key roles for their host functioning and are rich sources of bioactive natural compounds. Here, we describe the fundamental steps of metataxonomic analysis of microbial communities associated with marine organisms.
The present study approaches towards the feasibility of prediction and forecasting of dissolved oxygen (DO) and biofloc amount using the state of art machine learning algorithms in a shrimp culture system. The study was carried out considering; average DO and biofloc amount as target parameters in a shrimp culture system. There were seventeen numbers of culture and meteorological parameters considered and three different feature selection techniques used to create twelve different data subsets for model development. The model development was carried out using three popular machine learning algorithms viz., Random Forest, Adaboost and Deep neural network. The totals of thirty-six different models were obtained and their accuracies were evaluated with seven model validation tests and results were obtained and discussed. Out of thirty-six models, Random Forest technique applied model for prediction of dissolved oxygen with combined culture and meteorological parameters (R²value – 0.709, prediction accuracy – 98.26%, score – 0.7381) was found to be the best one for predictive model development. Moreover, exploratory data analysis was carried out for prediction and a framework for prediction of DO and biofloc amount in a shrimp based biofloc culture system was developed. The dissolved oxygen was found to be more robust in the predictive model development. The Intelligent Framework was developed based on the study conducted to understand and carryout prediction in farming system in a scientific manner. The developed framework can help the literate farmers and new entrants of shrimp farming to devise their own prediction models suitable for the farming conditions.
Increasing availability of automated systems and technological solutions have been one of the most important trends in aquaculture nutrition for the past few decades as the industry focuses on improving feeding strategies through highly efficient automatic feeding technologies. Monitoring of aquatic animals is not a new practice but for the last few decades aquaculture has used feeding behavior monitoring as a tool to develop efficient demand feeders. While there are many devices available for the fish production sector, many rely on visual monitoring of individuals or populations, which disable its application in most shrimp production systems. However, production of sound by the mandibular occlusion has led to the study of passive acoustic monitoring of feeding behavior in shrimp and the development of passive acoustic demand feeding systems. While this technology has been available for less than a decade it has already been validated and adopted by the shrimp production industry. It is expected to continue being improved as more data is collected on both acoustic profiling and feeding algorithms. The objective of this publication is to present a detailed review of the information available so far about acoustic profiling of shrimp, the results of the application of this acoustic feeding system in production systems, discussing the limitations of this technology and what components could be improved in the future.
The continued success of shrimp farming will rely on improved feed management and reductions in labor costs. Shrimp are omnivorous, eating many small meals with limited stomach capacity for food storage. Hence, increased performance may be obtained by spreading feed through multiple meals. Initial work has demonstrated that moving from two feeding per day into multiple feeding systems increases growth rate and production. Further advances have been made with on-demand (satiation) feeding systems. The goal of this work was to continue the development of standard feeding protocol's (SFP) for automatic feeding systems to maximize growth rates in semi-intensive pond production of shrimp, Litopenaeus vannamei. For this work a 13-week pond production trial was performed in 16, 0.1 ha outdoors ponds, stocked at a 26 shrimp/m², and fed 1.5-mm 40% crude protein for the first four weeks, and 2.4-mm protein soy optimized feed (35% crude protein) for last nine weeks, both produced by Zeigler Inc. Four treatments including: three fixed feeding treatments of 130, 145 and 160% of a SFP (SFP + 30%, SFP + 45%, SFP + 60%, respectively) were offered using automatic timer-feeders, and a fourth treatment utilized on-demand AQ1 acoustic feeding system. No statistical differences were found between treatments for survival (ranging 75.2–81.4%) and FCR (ranging 0.96–1.11). In general, increased feed inputs resulted in higher production. The best response was with the AQ1 system which adjusted feed inputs in real time and ended up offered higher feed inputs resulting in larger shrimp and yields. Based on results of this work and previous trials, standard feeding protocols for automated systems can be developed but to date, automated feedback systems which operate in real time out perform the standardized practices.
Biofloc systems are microbial mature environments that are potentially less conducive disease outbreaks. We hypothesized that the way in which biofloc microbial communities are managed determines the level of disease protection. To investigate such hypothesis, Litopenaeus vannamei post-larvae were cultured for 21 days in biofloc environments created by different water management procedures. Five different types of bioflocs were created: autotrophic bioflocs without probiotics, autotrophic bioflocs with probiotics, heterotrophic bioflocs without probiotics, heterotrophic bioflocs with probiotics, and a flow-through system as a control. Heterotrophic bioflocs were obtained by daily addition of carbon (glucose) at an estimated C/N ratio of 18 throughout the experiment. For autotrophic bioflocs this input of carbon was applied only to start up the system and upon appearance of bioflocs (TSS > 100 mg L ⁻¹ ) and a drop in total ammonium nitrogen concentration below 0.05 mg L ⁻¹ , carbon dosing was stopped. Bioflocs cultured with addition of probiotics received a 0.5 ppm dose every 48 hours. After 21-d culture period, a 96 h challenge test was performed with a Vibrio parahaemolyticus strain known to cause AHPND. For each biofloc type, this challenge was performed in three different approaches: 1- Shrimp were taken out of their biofloc tanks and challenged by applying new seawater; 2-Shrimp from biofloc tanks were challenged in their respective biofloc suspensions; and 3- Non-experimental shrimp, randomly selected from a recirculation (RAS) system were challenged in the types of biofloc suspensions. Mortality was high when shrimp were challenged in new seawater, independent of treatment. When challenged in their respective biofloc suspensions shrimp survival was the highest in heterotrophic bioflocs with and without probiotic supplementation and the autotrophic bioflocs with probiotics, whereas shrimp survival in autotrophic bioflocs without probiotics was 50%. These results were similar when non-experimental shrimp originating from a RAS system were challenged in these biofloc suspensions. Taken together, results suggest that bioflocs as such can decrease the impact of a Vibrio parahaemolyticus challenge and that this protection depends on the operational parameters of the biofloc system. Moreover, probiotics can be used to complement the protective effect of bioflocs. This information reinforces the importance of microbial community management as a tool to reduce the risk of disease and establish highly biosecure systems.
This study aimed to evaluate the effect of temperature-salinity interaction on physico-chemical parameters, plankton composition, performance growth, and survival of shrimp Penaeus vannamei raised in intensive nursery production with biofloc system and zero-water exchange, by means of the response surfaces analysis. A 3 × 3 factorial experiment was conducted to determine the effects of temperature (24, 28, and 32 °C) and salinity (10, 20, and 30 g L⁻¹) on water quality, performance, growth, and survival of Penaeus vannamei with the initial wet body weight of 0.004 ± 0.001 g. The experiment lasted for 4 weeks. The temperature and salinity, independent and their interaction, had a differential effect on the studied parameters. At higher temperatures, there was a significant tendency to increase the concentration of total ammonia‑nitrogen, nitrite, nitrate, total suspended solid and sedimentable solid, and lower dissolved oxygen concentration was found. Chlorophyta and rotifers were the most dominant groups of phytoplankton and zooplankton in the studied biofloc, respectively. The results showed that all shrimp had survivals above 84.5% at temperatures of 24–28 °C. The survival decreased with increasing the temperature from 28 to 32 °C. All growth parameters increased with the increase of salinity in the 24–28 °C temperature range, reaching a maximum value at 32 °C and 20 g L⁻¹. In contrast, FCR decreased in response to increasing temperature within the tested salinity. The results of the response surface methodology demonstrated the effects of temperature-salinity interaction on the growth and survival of the postlarvae and early juveniles of shrimp P. vannamei in the biofloc system. The optimum conditions to obtain the maximum specific surface area of final weight, feed conversion ratio, specific growth rate, weekly growth gain, productivity, and survival were temperature of 27.25 °C and salinity of 25.5 g L⁻¹, which were derived from the optimization approach. The results of this study help illustrate the range of temperatures-salinity options of shrimp raised for intensive nursery production in commercial-scale biofloc systems.
A 16‐week indoor culture trial was conducted to evaluate the effect of varying C:N ratio on growth performance, physico‐chemical parameters, microbial dynamics, feed utilization, and immunological parameters. The experiment comprised of five biofloc treatment groups (with varying C:N ratio 5:1, 10:1, 15:1, 20:1) and a control with three replicates each, having 100 nos/m3 as stocking density in 500 L tanks with constant aeration. The C:N ratios of the treatments were manipulated using molasses as an organic carbon source whereas there was no carbon source added in control. The water quality parameters monitored throughout the experiment were found to be within permissible limits in shrimp culture. At the end of the experiment, it was observed that there were significant differences between the treatment groups and the control regarding absolute growth, SGR, FCR, PER, and FER. Furthermore, a considerable difference in immunological parameters, namely, THC, phagocytosis, and PO activity (17.5 × 106 cells per ml, 43.5%, 0.112 Units min−1 mg min−1), was recorded among the treatments compared to that of the control groups (6.2 × 106 cells per ml, 31.5%, 0.051 Units min−1 mg min−1) respectively. Enhanced growth and survival with substantial disease resistance were recorded in C15 treatment. The results indicate that the CN15 ratio coupled with minimal water exchange is optimal for improved survival, growth, and immune activity.
Minimal-exchange, intensive biofloc aquaculture systems offer a viable means of culturing marine animals at inland locations due to very low rates of water use. Fresh, never-frozen shrimp can be provided to metropolitan markets; however, the cost of artificial salt can be substantial. The purpose of this project was to examine commercial-scale biofloc shrimp production at three different salinities. Nine raceways were randomly assigned to three salinity treatments: 10, 20, and 30‰ (LS, MS, and HS), each treatment contained three raceways operated at 50 m³. The raceways were operated as heterotrophic biofloc systems, with daily additions of sucrose to raise the C:N ratio. Temperature, dissolved oxygen, pH, and salinity were all maintained at consistent levels. Spikes of ammonia and nitrite occurred in all tanks but nitrate remained low, with a peak value of 8.7 mg NO3-N L− 1. There were no significant differences in any shrimp production metric. Mean shrimp growth rate was 1.8, 2.0, and 2.0 g week− 1 in the LS, MS, and HS treatments respectively. Mean feed conversion rate was 1.6, 1.2, and 1.2 in the LS, MS, and HS treatments respectively, and mean final weight ranged from 17.8 to 19.3 g. The only time water was removed from the systems was when settling chambers were emptied, resulting in a total mean water replacement of 5.2% or less per raceway. The mean volume of full strength seawater used to produce shrimp was 104, 159, and 235 L kg− 1 of shrimp in the LS, MS, and HS treatments respectively. Although there were no significant differences in shrimp production metrics between treatments, these values were noticeably lower in the LS treatment due to human error. Operating at the low salinity of 10‰ reduces salt use by about 50% over the MS treatment which implies substantial cost savings for production facilities. This study helps to illustrate the range of salinity options for shrimp production in commercial-scale biofloc systems.
The objective of this study was to document the immunological effects of growing shrimp in biofloc systems. The experiment consisted of four types of biofloc systems in which bioflocs were produced by daily supplementation of four different carbon sources, i.e. molasses, tapioca, tapioca-by-product, and rice bran, at an estimated C/N ratio of 15 and a control system without any organic carbon addition. Each biofloc system was stocked with Pacific white shrimp (Litopenaeus vannamei) juveniles that were reared for 49 days. The use of tapioca-by-product resulted in a higher survival (93%) of the shrimp as compared to the other carbon sources and the control. The highest yield and protein assimilation was observed when tapioca was used as the carbon source. After 49 days, phenoloxidase (PO) activity of the shrimp grown in all biofloc systems was higher than that of the shrimp from the control system. Following a challenge test by injection with infectious myonecrosis virus (IMNV), the levels of PO and respiratory burst (RB) activity in the shrimp of all biofloc treatments were higher than that of the challenged shrimp from the control treatment. An increased immunity was also suggested by the survival of the challenged shrimp from the experimental biofloc groups that was significantly higher as compared to the challenged shrimp from the control treatment, regardless of the organic carbon source used to grow the bioflocs. Overall, this study demonstrated that the application of biofloc technology may contribute to the robustness of cultured shrimp by immunostimulation and that this effect is independent of the type of carbon source used to grow the flocs.