Aquaculture Practices Research Articles

Nitrite Cycling in Freshwater Ecosystems: A Case Study of an Artificial Reservoir in Eastern China Using Nitrite Dual Isotopes Combined with a Geochemical Model

Reservoirs are hotspots for emissions of the greenhouse gas nitrous oxide; however, the nitrite cycling processes associated with nitrous oxide production therein remain poorly understood, limiting a better assessment of the potential for reservoirs to emit nitrous oxide. Accordingly, this study presents the application of the natural abundance isotope technique combined with a geochemical model to elucidate the nitrite cycling in the freshwater aquaculture and non-aquaculture zones of a large artificial reservoir in eastern China. We employed nitrite dual isotopes to identify nitrite transformation processes. Additionally, a steady-state model was used to estimate the rates of these processes as well as the residence time of nitrite. Our findings indicate that nitrite production in this reservoir may be primarily driven by ammonia oxidation. However, the pathways of nitrite removal differ notably between the aquaculture and non-aquaculture zones, suggesting a significant impact of the aquaculture activities. The steady-state model calculations revealed that nitrification may be more pronounced in the aquaculture zones compared to the non-aquaculture zones, which may be related to the altered balance of competition for substrates between phytoplankton and microbes induced by aquaculture activities. Moreover, we observed a latitude-dependent increase in the significance of nitrite oxidation in natural environments, highlighting potential implications for regional and global nitrogen cycling. Our study highlights the complexity of the nitrite cycle and emphasizes the roles of both natural and anthropogenic factors in shaping nitrogen dynamics within freshwater reservoirs. This understanding contributes to a more accurate assessment of the greenhouse gas emission potential of reservoirs, offering valuable implications for the adoption of sustainable aquaculture practices to mitigate climate impacts and support global sustainable development goals.

Inland Fisheries in Telangana, India: Current Status and Perspectives

Inland fisheries refer to the practice of harvesting fish from freshwater ecosystems such as lakes, rivers, and wetlands. These fisheries play a vital role in providing food security and livelihood opportunities for millions of people. The inland fisheries sector in Telangana is an essential component of the state's socio-economic framework, contributing to livelihoods, food security, and overall economic development. Telangana, blessed with vast inland water resources, holds considerable potential for enhancing fisheries production through reservoirs, tanks, and rivers. This research provides a comprehensive review of the current status of inland fisheries in Telangana, emphasizing its contribution to the state's Gross State Domestic Product (GSDP) and the well-being of fishing communities. The study explores government initiatives, fish production trends, and the challenges faced by the sector. The findings underscore the need for sustainable management and enhanced aquaculture practices to bridge the gap between supply and demand.

Epigenetic Resources: Gaps in Aquatic Animal Germplasm Research

ABSTRACTAquatic animal germplasm research plays a vital role in biodiversity conservation and sustainable aquaculture. The traditional view is that diversity of germplasm resources is commonly attributed to genetic variation. However, recent studies in transgenerational epigenetics have shown that epigenetic information can also be passed down to offspring, which is consistent with the definition of germplasm. Therefore, it is necessary to define epigenetic information, such as DNA methylation, histone modifications, and ncRNAs, which can be passed down through generations, as epigenetic resources and incorporate them into the concept of germplasm. Germplasm resources should include not only genetic resources but also epigenetic resources. Epigenetic variation can arise from genetic, environmental, or stochastic factors. Genetic and epigenetic variation co‐determine phenotypic traits. It has been demonstrated that epigenetic information can be inherited across generations in aquatic animals. DNA methylation, histone modification, and ncRNAs are involved in addressing environmental challenges, maintaining genetic diversity, improving breeding strategies, combating inbreeding decline, and age determination. Therefore, future research on epigenetic resources is important for germplasm conservation, development, and utilization. This review proposes a new theoretical framework to elucidate the place of epigenetic resources in germplasm research and collects articles from the past 8 years that explore the inheritance of epigenetic information in aquatic animals. Integrating epigenetic research into germplasm studies enhances our understanding of population dynamics, adaptation, and evolutionary processes, thereby informing conservation strategies and enhancing aquaculture practices. By considering both genetic and epigenetic resources, we can address the challenges facing germplasm diversity and sustainable aquaculture more comprehensively.

Understanding Fish Immunity and Innovative Vaccination Approaches in Aquaculture

Fish possess a unique immune system that, while somewhat similar to mammals, exhibits distinct characteristics. This review paper explains the complexities of fish immunity, highlighting the innate and adaptive immune responses that protect against various pathogens, including bacteria (Aeromonas spp, Flavobacterium columnare, Mycobacterium marinum, Streptococcus iniae, Edwardsiella tarda, Pseudomonas aeruginosa etc), viruses (Infectious Hematopoietic Necrosis Virus (IHNV), Viral Hemorrhagic Septicemia Virus (VHSV) etc.), fungi and parasites (Dioctophyma renale etc). Host-pathogen interactions are dynamic and critical for understanding the immune evasion strategies employed by pathogens, such as antigenic variation, molecular mimicry and biofilm formation. Vaccination is crucial in aquaculture, enhancing fish immunity against diseases through various vaccines, including inactivated, live, subunit, and nucleic acid vaccines. Various delivery methods are employed to maximize immunogenic responses, such as injection, immersion, and oral administration. Additionally, advancements in science and technology have led to innovative techniques to increase vaccine efficacy, including nanoparticle delivery and microencapsulation. Successful vaccination strategies have been adapted to combat significant fish pathogens, demonstrating the potential for enhancing disease resistance in aquaculture. This comprehensive overview underscores the importance of understanding fish immune systems and developing effective vaccination strategies to ensure fish health and sustainability in aquaculture practices.

Immunomodulatory effect of shrimp by-products in diets for Nile tilapia (Oreochromis niloticus)

Aquaculture plays a critical role in food security, with Nile tilapia (Oreochromis niloticus) being one of the most widely farmed species due to its resilience and adaptability. However, the reliance on traditional feed ingredients poses sustainability challenges. This study aimed to investigate the immunomodulatory effects of incorporating shrimp cephalothorax lipid extract (SCLE) and shrimp cephalothorax meal (SCM) in Nile tilapia diets as sustainable feed alternatives. Two experiments were conducted using diets with varying levels of SCLE (0.4%, 0.8%, 1.2%, and 1.6%) and SCM (5%, 10%, 15%, and 20%). A total of 200 healthy, uniformly sized Nile tilapia fingerlings were selected for two trials with average weights of 4.38±0.13 g and 3.24±0.07 g, respectively. Fish were distributed across 20 tanks and fed ad libitum for 45 days. Hematological parameters were analyzed, revealing that diets with SCLE significantly increased leukocyte, thrombocyte, and hematocrit levels, particularly at 1.6% inclusion. SCM inclusion also led to higher leukocyte counts, especially at 20%. These findings suggest that SCLE and SCM positively impact the innate immune system of Nile tilapia, enhancing their ability to resist pathogens. Additionally, the use of shrimp by-products in aquafeeds presents a viable strategy for reducing environmental waste and promoting more sustainable practices in aquaculture.

Management of Broodstock for Pacific White Shrimp (Litopenaeus vannamei) at the Center for Superior Shrimp and Shellfish Broodstock Production (BPIU2K) Karangasem, Bali

Shrimp (Litopenaeus vannamei), as it directly impacts the quality and quantity of larvae produced for aquaculture. This study investigates the management practices at the Center for Superior Shrimp and Shellfish Broodstock Production (BPIU2K) in Karangasem, Bali, focusing on the broodstock selection, breeding, and maintenance processes. The research evaluates the performance of broodstock in terms of growth, reproductive health, and overall productivity, aiming to optimize practices for sustainable shrimp farming. Data was collected through direct observation, water quality analysis, and broodstock health assessments. The findings highlight the importance of proper environmental conditions, nutritional management, and genetic selection in enhancing the reproductive success of L. vannamei. The study also discusses challenges faced by the facility, including disease management and genetic diversity, offering recommendations for improving broodstock management to ensure consistent, high-quality shrimp production. The number of male broodstock in the maintenance tank was around 250, and female broodstock was around 200, with a survival rate of 70%. This research contributes to advancing sustainable aquaculture practices and improving the shrimp farming industry in Indonesia.

Molecular pathways of osmoregulation in response to salinity stress in the gills of the scalloped spiny lobster (Panulirus homarus) within survival salinity

Scalloped spiny lobster (Panulirus homarus) aquaculture is the preferred strategy to resolve the conflict between supply and demand for lobster. Environmental conditions, such as salinity, are key to the success of lobster aquaculture. However, physiological responses of P. homarus to salinity stress have not been well studied. This study investigated the gill histology, osmoregulation and gill transcriptome of the early juvenile P. homarus (weight 19.04 ± 3.95 g) cultured at salinity 28 (control), 18, and 38 for 6 weeks. The results showed that the gill filaments of P. homarus exposed to low salinity showed severe separation of the cuticle and epithelial cells due to water absorption and swelling, as well as the dissolution and thinning of the cuticle and the rupture of the septum that separates the afferent and efferent channels. The serum osmolarity of P. homarus varied proportionately with external medium salinity and remained consistently above ambient osmolarity. The serum Na+, Cl−, K+, and Mg2+ concentrations P. homarus exhibited a pattern similar to that of serum osmolality, while the concentration of Ca2+ remained unaffected at salinity 18 but significantly increased at salinity 38. Gill Na+/K+-ATPase activity of P. homarus increased (p < 0.05) under the both salinity stress. Salinity 18 significantly increased Glutamate dehydrogenase (GDH) and Glutamicpyruvic transaminase (GPT) activity in the hepatopancreas of P. homarus (p < 0.05). According to transcriptome analysis, versus control group (salinity 28), 929 and 1095 differentially expressed genes (DEGs) were obtained in the gills of P. homarus at salinity 18 and 38, respectively, with these DEGs were mainly involved in energy metabolism, transmembrane transport and oxidative stress and substance metabolism. In addition, the expression patterns of 8 key DEGs mainly related to amino acid metabolism, transmembrane transport and oxidative stress were verified by quantitative real-time PCR (RT-qPCR). The present study suggests that salinity 18 has a greater impact on P. homarus than salinity 38, and P. homarus demonstrates effective osmoregulation and handle with salinity fluctuations (18 to 38) through physiological and functional adaptations. This study provides an improved understanding of the physiological response strategies of P. homarus facing salinity stress, which is crucial for optimizing aquaculture practices for this species.

Effects of aflatoxin B1 on subacute exposure of hybrid groupers (Epinephelus fuscoguttatus♀ × Epinephelus lanceolatus♂): Growth, liver histology, and integrated liver transcriptome and metabolome analysis

With the increasing incorporation of plant-based ingredients into the grouper diet, the issue of aflatoxin B1 (AFB1) contamination in the diet has become a significant concern. In this study, the negative effects of AFB1 on the growth and liver health of hybrid grouper (Epinephelus fuscoguttatus♀ × Epinephelus lanceolatus♂) were investigated in the context of growth, liver histology, serum biochemical indices, and integrated transcriptomic and metabolomic data. A total of 540 healthy hybrid groupers, initially weighing 11.59 ± 0.03 g, were randomly divided into six groups (three replicates of 30 fish each): the Control group was fed a basal diet, and the experimental groups were supplemented with 7 (AF7), 30 (AF30), 111 (AF111), 445 (AF445) and 2230 μg/kg AFB1 (AF2230) in the basal diet respectively, for 56 days. Groups Control, AF445, and AF2230 were selected for subsequent histological, muscle fatty acid, and transcriptomic and metabolomic analyses based on the results of hybrid grouper growth and serum biochemical indices. Compared to the Control group, both whole-body crude lipid and muscle crude lipid contents showed significant decreases in the AF2230 group (P < 0.05), while only muscle crude lipid content showed a significant decrease in the AF445 group (P = 0.001). Liver damage was seen in the histology of the liver of AF445 and AF2230 groups. Muscle fatty acid results showed that the addition of 445 and 2230 μg/kg AFB1 to the ration increased saturated fatty acids and monounsaturated fatty acids and decreased polyunsaturated fatty acids and highly unsaturated fatty acids in muscle (P < 0.05). Transcriptome analyses revealed multiple metabolic pathways associated with AFB1 metabolism, and metabolomics analyses further confirmed changes in the activity of these pathways. The results of the combined transcriptomic and metabolomic analyses indicated that AFB1 causes liver injury mainly by affecting liver retinol metabolism, metabolism of xenobiotics by cytochromes P450, drug metabolism-cytochromes P450 and biosynthesis of unsaturated fatty acids. In conclusion, dietary AFB1 levels above 445 μg/kg resulted in growth inhibition, liver injury, liver AFB1 accumulation, and reduced muscle polyunsaturated fatty acid content in grouper, thereby affecting muscle quality. This study provides novel insights into the detrimental effects of AFB1 on aquatic species and contributes to the scientific basis for the health and sustainability of aquaculture practices.

Mariculture in Croatia: A Spatial Perspective

Croatia has a highly indented coastline, favourable ecological conditions, proximity to the markets, and potential for further mariculture development. This research aims to determine the status of Croatian mariculture considering: distribution of fish and bivalve farms, total mariculture area, buffer zone, Internal Waters Utilization, nominal intensity, number of registered operators, and employees in the industry. The spatial database was created using manual vectorization from recent (2022/2024) Google Earth satellite imagery. The results show that marine farms in Croatia occupy 0.056% of the area of internal marine waters. Out of this, 53 % of the surface is dedicated to bivalve and 47% to fish farming. Croatia’s total nominal intensity is 3.3 t/km of coastline in 2022. Farms are located in all coastal counties, with the largest occupied area in Zadar County (38.1%) and Dubrovnik-Neretva County (37.5%). Most of the national fish farming area is located in Zadar County (71%), while the largest area of bivalve farming (68%) is found in Dubrovnik-Neretva County. In Primorje-Gorski Kotar County, despite having the largest area of internal marine waters, only 4.3% of the total mariculture area is present. The analysis indicates that mariculture currently occurs in a tiny portion of internal marine waters and has generally lower nominal intensity than other Mediterranean countries. Although mariculture is present in all coastal counties, the distribution and productivity of farms is uneven. For future development, we suggest focusing on optimizing current production capacities and exploring innovative aquaculture practices to enhance sustainability and economic viability.

Demand Forecasting for Aqua Tech Technical Textiles

Demand forecasting plays a significant role in the Aquatech industry, where innovation integration with aquacultural practices drives efficiency and effectiveness. This abstract outline the importance, challenges, techniques, and implications of demand forecasting in the sector. Demand forecasting is essential for businesses to anticipate trends, optimize resource allocation, and enhance operational efficiency. By accurately predicting future demand for aquacultural products, services, and technological outcomes, companies can make informed decisions regarding production, operations, and marketing strategies. However, demand forecasting in this industry faces several challenges, including seasonal variations, data availability, technological complexity, and uncertainties. Aquaculture demand is influenced by factors such as precipitation patterns, regulatory policies, and consumer preferences, making it difficult to develop precise forecasting models. Various techniques are used for demand forecasting, including statistical methods, data analytics, and machine learning algorithms. Time series analysis, regression analysis, and hybrid forecasting approaches are commonly employed to analyze historical data and predict future demand patterns. Accurate demand forecasting has significant implications for businesses, including improved resource planning, supply chain management, and customer satisfaction. By aligning production capacities with anticipated demand and optimizing supply levels, companies can minimize costs, reduce waste, and enhance competitiveness in the market. Demand forecasting is a critical aspect of strategic planning and decision-making in the specialized industry. By utilizing advanced techniques and effectively addressing challenges, businesses can enhance their ability to anticipate trends, meet customer demands, and drive sustainable growth in an increasingly dynamic and competitive environment

Shrimp Counting Algorithm Using a Small-Scale Labeling Model

This study presents an algorithm for shrimp counting using a small-scale labeling model. The aim is to enhance shrimp farming efficiency, reduce biosecurity risks, and minimize manual counting errors. Experimental evaluations were conducted using Litopenaeus vannamei samples divided into four growth stages. A comparison was made between the classical threshold segmentation method, small-scale labeling density estimation based on FamNet, and our proposed small-scale labeling density estimation based on FamNet-S models. The results showed that the proposed FamNet-S-based small-scale labeling density estimation method achieved a better level of accuracy than the classical FamNet model across different growth stages. In the first stage, it reduced the mean absolute error (MAE) by 8.7% and the mean squared error (MSE) by 9.6%. In the fourth stage, MAE and MSE further decreased by 18.9% and 21.6%, respectively. The research findings demonstrate that the small-scale labeling density estimation approach based on FamNet-S exhibits robust adaptability and accuracy across diverse growth stages, rendering it suitable for scenarios with limited annotated samples. It effectively tackles challenges associated with shrimp overlap and occlusion while mitigating interference from feed and excrement, thus enhancing the precision and efficiency of shrimp counting. This algorithm for small-scale labeling density estimation significantly reduces annotation workloads while facilitating rapid deployment, making it an ideal solution for counting and marking in practical aquaculture environments. The study provides a high-precision yet efficient methodology for shrimp counting and marking tasks, thus reducing labor intensity while improving farming management accuracy, thereby supporting intelligent control in shrimp farming.

Application of Photocatalytic Ozonation for the Remediation of Aquaculture Effluents: A Review

The growing global population and limitations in fish catch production have led to a surge in the demand for aquaculture. Contaminants of emerging concern (CEC) are frequently being detected at low levels in surface water. These CECs, which include previously unidentified or unregulated pollutants, pose potential risks to health and the environment, though their impacts are not yet fully understood. Extensive research studies have been proposed and undertaken to address the issue of aquaculture wastewater, aiming to minimize its impact and implement effective treatment methods. This review provides an analysis of various technologies used for treating aquaculture wastewater using advanced oxidation processes (AOPs) focusing on photocatalysis and ozonation. It examines their advantages and disadvantages, as well as their respective treatment efficacies, and discusses their potential applications in sustainable aquaculture practices complying with the Sustainable Development Goals of 1, 2, and 6 as well as being in line with the Environmental Social and Governance (ESG) framework.

Advancing Seaweed Cultivation: Integrating Physics Constraint in Machine Learning for Enhanced Biomass Forecasting in IMTA Systems

Monitoring seaweed growth rates and biomass is crucial for optimizing harvest strategies in aquaculture systems. While such a task can be managed manually on a small farm with a few seaweed tanks, it is not feasible on a commercial farm with 1000s of tanks. To this end, an Internet of Things (IoT) based seaweed growth monitoring system is being developed at Harbor Branch Oceanographic Institute (HBOI) at Florida Atlantic University (FAU). Using the Integrated Multi-Trophic Aquaculture (IMTA) system at HBOI as the test site, the project aims to develop a solution that allows farm managers to monitor seaweed growth remotely using automated sensors. An important component of this IoT solution is the machine learning-based prediction model. This study introduces an advanced Long Short-Term Memory (LSTM)-based approach for forecasting seaweed growth and biomass. In particular, an algae growth mathematical model driven by readily available environmental and aquaculture conditions has been integrated as a physical constraint in the LSTM model. This design addresses a principal challenge in this study—the lack of continuous ground truth measurements, as the biomass is recorded only at discrete intervals (e.g., initial, weekly partial harvests, and final harvest). The LSTM models are trained and evaluated for their predictive performance using experimental and synthetic data. Compared with the LSTM models with MSE loss function alone, the results showed that the model with a loss function under physics constraint achieved a significantly lower error in predicting seaweed growth. The rationale behind choosing LSTM over other state-of-the-art models is presented in the paper. This study highlights the potential of integrating machine learning with physical models to optimize seaweed cultivation and support sustainable aquaculture practices. The proposed methodology can seamlessly extend to the remote sensing data in other aquaculture settings.

Molecular insights into oocyte development and sperm storage in black rockfish (Sebastes schlegelii): Proteomic changes across reproductive stages

Sperm storage in females is widespread among vertebrates and insects, and the expression of proteins in the female reproductive tract is influenced by the presence of sperm, allowing for adaptation to this phenomenon. Through histological observation, we confirmed that sperm were stored in the isthmic fossa outside the oocyte during the post-mating (POM) stage, and closer to the epithelial cells during the pre-fertilization (PRF) stage. In addition, we observed asynchronous ovarian development in black rockfish, where oocytes at various stages could be identified during the PRF phase. This study investigated the ovarian protein expression changes in black rockfish (Sebastes schlegelii) during key reproductive stages: pre-mating (PRM), POM, unmated control (POM-CT), and PRF. A total of 5012 proteins were identified, with notable fluctuations in protein expression observed at the PRF stage. Specifically, 140 proteins were upregulated and 615 downregulated when compared to the PRM stage, while 101 proteins were upregulated and 531 downregulated in comparison to the POM stage. The functional enrichment analysis of differentially expressed proteins (DEPs) revealed distinct pathways: POM vs. PRM showed involvement in vesicle sorting and hormone signaling; PRF vs. POM indicated pathways related to chromatin remodeling and gene expression regulation; and POM vs. POM-CT highlighted pathways associated with immune response. These findings suggested that these signaling pathways may play a crucial role in oocyte development and sperm storage. The majority of DEPs were localized in the nucleus, with key interactions involving proteins such as GSK3B and MED1. These findings enhance our understanding of the molecular mechanisms underlying oocyte maturation and sperm storage, providing insights relevant to reproductive biology and aquaculture practices.

EFFECT OF FREQUENCY OF FEEDING HI-PRO-VITE 781N-1 ON THE GROWTH OF GOLDEN FISH (Cyprinus carpio) IN THE GOLDEN FISH BREEDING CENTER OF TOMONAMO IN LETEFOHO VILLAGE SUB DISTRICT SAME, MUNCIPLAITY OF MAUNUFAHI, TIMOR-LESTE

The purpose of this study was to determine the effect of the frequency of artificial feeding Hi-Pro-Vite 781N-1 on the effective growth of goldfish (Cyprinus carpio) in Timor Leste, Timor. The study used a complete randomized design (CRD) with 3 treatments and 3 replications, in which the conditions of the test unit are carried out according to randomization for all test units. The results of the research conducted for eight weeks (56 days) regarding the frequency for artificial feeding hi-pro-vite 780N-1 were: water temperature, water oxygen, sin water, and total dissolved solids (TDS) of 42.4 ppm, and the results of water quality measurements once a week in the morning (08.00 WIB), on average (20.00 htl) and in the afternoon (05.00) for 8 weeks (58 days). The results obtained during the research week (65 days) fresh at water temperature with a value of 20.2 oC with water oxygen 2.89 pmm, water content 8.3 pmm and TDS 42.4 pmm are indeed a good tolerance for the growth of carp fry (Cyprinus caprio). The behavioral impact of feeding frequency on carp growth and health is explored to refine feeding practices that promote well-being alongside growth. The findings could benefit feed manufacturers and aquaculture stakeholders by informing product development and feeding strategies tailored to maximize growth in carp, contributing to sustainable aquaculture practices. This study offers practical guidance for optimizing feeding practices to enhance growth efficiency, which is crucial for improving fish yield and farm productivity.

Assessing the Feasibility of Sustainable Aquaculture for Common Snook Centropomus undecimalis

ABSTRACTCommon Snook (Centropomus undecimalis) is widely distributed across the tropical Atlantic Coasts and has a significant economic impact. This review aims to assess the knowledge status of common snook, contributing significantly to the development of sustainable aquacultural practices. The review was conducted using Web of Science and Google Scholar to identify scientific articles analysing the biology and ecology, the status of snook fisheries and developments in aquaculture production. Researchers in the USA, Mexico and Brazil have conducted 37.95%, 25.52% and 26.21% of published research, respectively, focusing mainly on reproduction in natural environments, status of fisheries and aquaculture production. From an environmental perspective, it is essential to understand the factors impacting C. undecimalis populations. Climate change effects and human alterations to river courses pose significant threats. In addition to fishing regulations, there is a promising potential for further fisheries research and to deepen the understanding of the life cycle to support the implementation of sound aquacultural practices to replenish exploited stocks and to develop commercial aquaculture. Currently, C. undecimalis populations in Mexico and the United States are overexploited, focusing on México, which now has a management plan. Advances in controlled reproduction and larval development have been made. However, many challenges remain unclear, such as larval conditions that continue to represent a bottleneck to block continuous and large‐scale aquaculture production, larval nutrition, disease management and culture systems. However, aquaculture holds the potential to enhance the sustainability of this species by reducing fishing pressure and aiding population recovery.

Carbon footprint assessment and reduction strategies for aquaculture: A review

AbstractAquaculture generates less greenhouse gas emissions compared to other agriculture practices due to its limited land‐use changes, improved feed conversion rates, and reduced methane emissions from animals' digestive systems. The aquaculture carbon emissions come from various production stages, including feed production, farm operations, processing, transportation, and so forth. This review illustrates the theories, calculation methods, and practical applications of the carbon footprint in fisheries and aquaculture, as well as the challenges and strategies for emission reduction. The factors influencing the carbon footprint of fishing and manufacturing aquaculture are also discussed. Further research should focus on refining carbon footprint assessment techniques, promoting green technologies and sustainable aquaculture practices. Managing aquaculture's carbon footprint though is crucial for mitigating environmental impacts and supporting sustainable development.

Kalman Filter-Based Data Stabilization for an Automated Water Quality Monitoring System in Macrobrachium Rosenbergii Larvae Culture

Manual monitoring and management of water quality parameters in Macrobrachium Rosenbergii (freshwater prawn) larval culture are labourintensive, time-consuming, and susceptible to human error. This research aims to develop and evaluate an automated water quality monitoring system for freshwater prawn larval culture, with a specific emphasis on data stabilization. An ESP32 microcontroller is implemented to allow remote communication using an internet connection. The system continuously monitors critical parameters using sensors such as temperature, pH, turbidity, and Total Dissolved Solids (TDS), facilitating remote real-time data acquisition. The Message Queuing Telemetry Transport (MQTT) publish-subscribe protocol is employed for seamless communication between the microcontroller and the monitoring dashboard. A Kalman filter is integrated into the system, enabling real-time sensor noise reduction and dynamic adaptation to changes. The filtered data are displayed remotely using a Node-RED dashboard with graphical representations. The implementation of the ESP32 microcontroller with the MQTT protocol and Node-RED has proven to be a robust platform for seamless data communication and presentation. Integration of the Kalman Filter significantly mitigates fluctuations in sensor readings. This is further proven by comparisons of the filtered data with known-good sensors, which have shown minimal to acceptable error percentages between 1% - 8.5%, where the error can mainly be attributed to environmental factors. Overall, this study has established a framework that can contribute to improving aquaculture practices and promoting environmental sustainability infreshwater prawn culture operations. The validated system provides valuable insights that assist farmers in facilitating a more efficient prawn culture operation.

Comparative Analysis of Growth Performance, Morphological Development, and Physiological Condition in Three Romanian Cyprinus carpio Varieties and Koi: Implications for Aquaculture.

This study investigates the influence of internal factors on growth dynamics in four Cyprinus carpio varieties, three Romanian strains (Frăsinet, Ineu, and Podu Iloaiei) and the Koi variety. Fish were measured for total length, maximum height, and weight at four ontogenic stages, namely 7 days post-hatch, 3 months (0+), 18 months old (1+), and 36 months (2+). Weight Gain (WG), Specific Growth Rate (SGR), Relative Growth Rate (RGR), Fulton's condition factor, and the profile index were calculated and analyzed. Results revealed significant intervariety differences in growth performance and physiological condition across life stages. At the 2+ stage, Podu Iloaiei exhibited the highest WG (849.73 ± 4.09 g), while Koi showed the lowest (403.99 ± 14.21 g). Koi demonstrated a unique growth pattern, with the highest SGR (0.18 ± 0.00% day-1) and RGR (0.98 ± 0.05 g day-1) at the 2+ stage. Fulton's condition factor varied markedly, with Frăsinet showing the highest value at 7 days post-hatch (149.57 ± 17.485) and Koi the lowest at the 1+ stage (0.63 ± 0.011). The profile index decreased with age in all varieties, with Podu Iloaiei showing the most dramatic change from 4.22 ± 0.149 at 7 days to 2.18 ± 0.004 at 2+. These findings highlight the complex interplay between genetic and developmental factors in carp varieties, offering new insights for tailored breeding programs and aquaculture practices.

Unveiling Emerging Opportunistic Fish Pathogens in Aquaculture: A Comprehensive Seasonal Study of Microbial Composition in Mediterranean Fish Hatcheries.

The importance of microbial communities in fish hatcheries for fish health and welfare has been recognized, with several studies mapping these communities during healthy rearing conditions and disease outbreaks. In this study, we analyzed the bacteriome of the live feeds, such as microalgae, rotifers, and Artemia, used in fish hatcheries that produce Mediterranean species. Our goal was to provide baseline information about their structure, emphasizing in environmental putative fish pathogenic bacteria. We conducted 16S rRNA amplicon Novaseq sequencing for our analysis, and we inferred 46,745 taxonomically annotated ASVs. Results showed that incoming environmental water plays a significant role in the presence of important taxa that constitute presumptive pathogens. Bio-statistical analyses revealed a relatively stable bacteriome among seasonal samplings for every hatchery but a diverse bacteriome between sampling stations and a distinct core bacteriome for each hatchery. Analysis of putative opportunistic fish pathogenic genera revealed some co-occurrence correlation events and a high average relative abundance of Vibrio, Tenacibaculum, and Photobacterium genera in live feeds, reaching a grand mean average of up to 7.3% for the hatchery of the Hellenic Center of Marine Research (HCMR), 12% for Hatchery A, and 11.5% for Hatchery B. Mapping the bacteriome in live feeds is pivotal for understanding the marine environment and distinct aquaculture practices and can guide improvements in hatchery management, enhancing fish health and sustainability in the Mediterranean region.