Aquaculture International最新文献

This study examines the potential of circular economy practices to enhance the environmental sustainability of aquaculture, focusing on rainbow trout farming. Utilising life cycle assessment (LCA), the research evaluates the environmental and energy performance of the production system of an aquaculture company situated in Italy and identifies its main hotspots. A functional unit of 1 ton of rainbow trout live weight is used, with data collected directly from the farm throughout the production cycle, from hatchery to on-growing phases, within a cradle-to-gate framework. Secondary data supplement missing information and background processes. The environmental impacts are calculated by applying the CML-IA baseline and Cumulative Energy Demand methods. The results indicate that environmental impacts are distributed between the pre-fattening and on-growing phases, with a lesser contribution from the hatchery phase. Key hotspots include feed and energy usage, prominently affecting global warming, eutrophication and acidification. Then, the effects of three circular actions are evaluated: recycling slurry as fertiliser, reducing pressure on wild fish stocks, shifting to insect-based feed and transitioning from non-renewable energy sources to photovoltaic energy to enhance sustainability further. The transition to insect-based feed could generate the highest benefits, reducing global warming potential by 14% and freshwater aquatic ecotoxicity by 15%, despite minor trade-offs in marine ecotoxicity. The findings underscore the transformative potential of CE in aligning aquaculture with sustainability goals and underline LCA as a crucial tool for identifying environmental challenges and validating strategies.

Stimulation of antioxidant systems with metabolic changes by signaling molecules such as ascorbic acid (AA) is a common stress tolerance strategy in plants and algae. The effect of AA on tolerance to long-term salinity of the green microalga Dunaliella salina was investigated by studying biochemical changes and enzymatic antioxidant responses. Algal cells adapted to three salinity levels of 1, 2, and 3 M NaCl were treated with or without 1 mM AA in exponential growth phase. AA-untreated suspensions at 3 M showed lower cell number and protein carbonylation but highly accumulated levels of pigments, soluble sugars, starch, hydrogen peroxide, proteins, proline, and free amino acid and enhanced the activity of antioxidant enzymes, proteolysis, and lipid peroxidation. AA-treated suspensions at 3 M increased cell number, while decreased the activities of proteolytic and antioxidant enzymes relative to untreated controls. Protein carbonylation showed a mutual correlation with lipid peroxidation levels in both AA-treated and untreated cultures, indicating a unique pattern of protein modification in D. salina. However, AA was ineffective in the accumulation of metabolites in 1 and 2 M suspensions and showed metabolite-reducing effects in algae grown in 3 M NaCl. These data suggest that exogenous AA can improve the tolerance of D. salina to 3 M salinity by regulating the activity of enzymes involved in the metabolism of carbon sources and diverting its metabolites to growth processes instead of the synthesis of osmoprotectant substances. Therefore, despite its prominent ecological role, AA is of little biotechnological importance due to its negative impact on accumulation of desired metabolites.

The green synthesis nanoparticles formulated in aquatic feed were commonly studied nowadays to improve aquatic product immunity and mitigate disease occurrence due to their effectiveness, safety, and lower cost. This study was assessed to investigate the effect of Melaleuca cajuputi-synthesized gold nanoparticles (MC-AuNPs) at various concentrations (i.e., 0%, 10%, 40%, and 70%) and feeding periods: short-term (4 days) and long-term (30 days) on immunity and histology of the whiteleg shrimp Litopenaeus vannamei. The selected concentrations used are based on our previous study on the antibacterial properties of MC-AuNP diets against Vibrio parahaemolyticus. Following feeding, shrimps were then challenged with Vibrio parahaemolyticus to assess their resistance and histological alterations. Results showed that the shrimp fed with 10% and 40% MC-AuNP diets for both short-term and long-term feeding periods increased the biochemical and hematological parameters of the shrimp. After the challenge with V. parahaemolyticus, abnormal lumens were seen, while the hepatopancreatic cells and tissue in the 10% and 40% MC-AuNP diets appeared normal. Improved survival rates were observed in all shrimp supplemented with MC-AuNP diets, particularly in 10% and 40%. The findings suggest that the inclusion of 10% and 40% MC-AuNP diets for short-term feeding periods was recommended to be further studied as shrimp immunostimulants due to their potential to improve shrimp immunity with minimal histopathological changes to the shrimp hepatopancreas.

The digital transformation of China’s traditional aquaculture industry has promoted the high-quality development of China’s aquaculture industry and helped China become one of the world’s largest aquaculture countries. In this paper, the current status of aquaculture digital transformation will be described from two perspectives: aquaculture process and aquaculture digital technology. The aquaculture process can be divided into eight steps by the eight-step intensive aquaculture method, and each aquaculture step and aquaculture digital intelligence technology are analyzed, revealing that technologies such as the Internet of Things (IoT), cloud computing, artificial intelligence, etc. promote high-speed growth of aquaculture productivity through the adjustment of aquaculture management decisions and the improvement of production factors, and that big data and blockchain technologies contribute to building a more trustworthy environment for online transactions and improving product traceability, offering potential steps toward integrated aquaculture. This review summarizes successful cases of digital transformation in Chinese aquaculture, providing a reference for the future development of digital aquaculture in the world. This review draws on the successful experience of China’s aquaculture transformation to help accelerate the adoption of digital intelligence in aquaculture plants around the world and to serve as a basis for the improvement of current and future digital intelligence technologies.

Accurately identifying fish feeding behavior in complex environments is crucial for optimizing feed management, improving feed utilization efficiency, and reducing aquaculture costs. Complex real-world environments, such as variations in water quality, lighting conditions, and background interference, make it difficult to distinguish feeding states. To address this issue, based on the fusion of attention mechanism-enhanced ResNet and an improved ConvNeXt (ResNet–MoVIT–ConvNeXt), a fish feeding intensity recognition method is proposed. A multi-scenario data augmentation method is designed to simulate complex fish feeding environments replicating real-world complex scenarios. The dual-branch model, combining ResNet and improved ConvNeXt, extracts local features from fish school images. The MobileViT module is then used for multi-level feature fusion, effectively capturing feeding behavior features for accurate feeding recognition. Finally, a multi-factor dynamic feeding strategy is provided, which combines fish biomass, water quality, and feeding states to reduce feed waste. This method introduces the MobileViT module into each stage of the ResNet and improved ConvNeXt networks. The proposed method is evaluated on real-world fish school datasets, achieving an overall accuracy of 99.19% and 98.5% for the medium state, surpassing existing comparative methods.

Microplastic (MP) contamination in aquaculture feed presents an increasing threat to both the aquaculture industry and global public health. This study examines the occurrence, abundance, characteristics, and risk assessment of MPs in commercial tilapia (Oreochromis niloticus) feeds. MP contamination was found in all feed samples, with the highest levels observed in grower feeds (2150 ± 70.71 MPs/kg), followed by starter feeds (1650 ± 70.71 MPs/kg) and finisher feeds (1300 ± 141.42 MPs/kg). Fibers were the dominant morphotype (85%), and polymer analysis using FTIR identified polypropylene (38.74%) and polyethylene (33.61%) as the most common polymers. Additionally, 84.64% of the extracted MPs were in the 100–1500 µm size range, posing significant health risks to tilapia and potential exposure to consumers. The estimated polymer hazard index (PHI) value for the three feed categories was very high, signaling alarming health risks. The mean polymer load index (PLI) values across the feed categories ranged from 4.23 to 8.03, indicating minor contamination. The study attributes the sources of MPs to feed ingredients, packaging materials, and processing machinery. The high PHI value underscores the need for urgent action to mitigate MP pollution in tilapia farming.

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The red seaweed Solieria filiformis is a source of nutrients, active biomolecules, and the iota(ι)-carrageenan hydrocolloid. In Brazil, it is found in natural stock; however, the sustainable biomass production of this seaweed species in the sea has not been reported. The S. filiformis cultivation was evaluated at Flecheiras Beach, on the coast of Ceara State in Northeast Brazil, using Long-line with Vertical Rope Structures (LVRS) and Colonized Modules (CM) methods during the rainy and dry seasons. The environmental parameters of the cultivation site, the daily growth rates (DGR) at 30, 45, and 60 days after planting, the biomass density, and the ι-carrageenan extracted were assessed. Local environmental conditions supported seaweed growth in both seasons. However, the highest DGR (6.1%) was recorded 30 days after planting during the dry season using LVRS. The highest seaweed biomass density was 53 kg ws module⁻¹ using CM method. The highest ι-carrageenan yields (48.3% and 53.1%) were obtained from the biomasses produced in the dry season, using LVRS and CM methods, respectively. The mean sulfate content of the ι-carrageenan extracted was 26.8 ± 1.9%, a relevant feature of their physicochemical properties and biological activities.

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The nursery phase in autumn is an important strategy for scaling up tilapia farming in subtropical regions, which otherwise suffers from a lack of fingerlings in winter. Tilapia nursery is carried out in a semi-intensive system in ponds; however, the biofloc technology system (BFT) has productive, environmental, and health advantages. This study aimed to compare the production of Nile tilapia (Oreochromis niloticus) juveniles in two rearing systems during autumn through the evaluation of fish growth performance, environmental, and hematological parameters, as well as production costs. The 46-day experiment was conducted on a pilot scale, with four experimental units per system stocked with fingerlings averaging 1.95 ± 0.32 g. In the semi-intensive system, 25 m³ ponds were used, and each was stocked with 1100 fingerlings (44 fish m⁻³). In the super-intensive system, 4 m³ circular tanks were used, each stocked with 2200 fingerlings (550 fish m⁻³). The production of tilapia juveniles in BFT showed greater stability of water quality parameters throughout rearing in association with higher water temperature owing to the greenhouse. This allowed similar growth between fish in both systems, but with productivity 12.7-fold higher in BFT, while consuming 29.6 times less water. Hematological parameters among fish in the two systems were also similar. Moreover, the BFT system demonstrated a 6.2% reduction in total operating costs compared to the semi-intensive pond system, positioning it as a more cost-effective option for producing Nile tilapia juveniles in subtropical regions. These results highlight the BFT system’s potential as a viable alternative for rural fish farmers.

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Quantum dots (QDs), a modern nanotechnology, have emerged as a transformative tool in aquaculture, enhancing efficiency and sustainability. This review highlights QD applications in detecting waterborne pathogens and pollutants through fluorescence, monitoring water quality parameters in real-time, targeted delivery of vaccines and therapeutics, and improving nutrition through nano-encapsulated feed supplements. QD’s unique optical properties enable sensitive and selective detection, while their small size facilitates cellular uptake and targeted delivery. Benefits of quantum dots in aquaculture include disease management, enhanced water quality, increased feed efficiency, and reduced environmental impact. Furthermore, recent applications of nano-inspired genes, nano-sensors, DNA-based nano-vaccines, and medication delivery systems have positively impacted fish health, immune systems, and reproduction. However, toxicity concerns and regulatory frameworks must be addressed. This comprehensive review provides an overview of QD applications in aquaculture, highlighting opportunities, challenges, and future research directions, ultimately contributing to a more sustainable and efficient aquaculture industry.

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