Aquaculture International最新文献

As one of the fastest-growing sectors in global food production, aquaculture has raised increasing concerns about its environmental impacts. This study is the first to conduct a life cycle assessment (LCA) of the China’s Manila clam (Ruditapes philippinarum) supply chain, focusing on the stages of seed rearing, farming, and processing, and comparing the environmental impacts of south-north relay aquaculture and northern seed rearing-farming supply chains. The LCA results indicate that Marine Aquatic Ecotoxicity Potential (MAETP) accounts for the highest environmental burden among all impact categories. In order to the high electricity consumption, seed rearing stage has the highest environmental impacts. Moreover, the south-north relay aquaculture supply chain has an environmental burden due to long-distance transportation; therefore, the northern seed rearing-farming supply chain is a more sustainable strategy and local seed rearing in northern regions was recommended. Further analysis reveals that energy consumption is the main sources of environmental impact in the whole supply chain; two energy improvement scenarios are proposed: scenario 1 (photovoltaic power generation and diesel-powered transport vessels) and scenario 2 (wind power generation and diesel-powered transport vessels). The simulation results demonstrate that these scenarios could reduce the environmental impact potential of the supply chain by 80.51% and 82.32%, respectively. The application of renewable energy will significantly decrease the environmental burdens and provide useful measures to the sustainable development of the Manila clam supply chain in China.

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This study aims to explore the effects of adding different doses of allicin to the feed on the growth performance of snakehead fish (Channa argus) and its protective effect against lipopolysaccharide (LPS)-induced pathological damage. Allicin was added to the basal diet at levels of 0, 50, 100, 200, and 400 mg/kg, respectively. After 56 days of continuous feeding, the fish were treated with an LPS injection. The results indicated that an appropriate amount of allicin could significantly improve the growth performance of snakehead fish. Among them, the 200 mg/kg allicin group significantly enhanced the serum immune level after LPS treatment and alleviated the pathological damage of liver and intestinal tissues. Meanwhile, allicin can significantly reverse the mRNA expression of pro-apoptotic genes (such as caspase-3, caspase-8, etc.) and anti-apoptotic gene (bcl-2) in the intestine and liver induced by LPS. By inhibiting the NF-κB signaling pathway, allicin significantly reduced the mRNA expressions of pro-inflammatory factors (such as il-1β, tnf-α, etc.) and increased the levels of anti-inflammatory factors (il-10, tgf-β), thereby enhancing the immune ability. It alleviated the inflammatory response, down-regulated the mRNA expression levels of endoplasmic reticulum stress-related genes (such as perk, ire-1α, etc.), and up-regulated the expression of genes related to tight junction proteins, thus improving the intestinal barrier function. Through analysis, the optimal addition amount of allicin was 220.969 mg/kg, which could significantly improve the growth performance of C. argus. Dietary supplementation with 100 and 200 mg/kg allicin significantly improved final body weight (FBW), specific growth rate (SGR), and weight gain (WG) in C. argus compared to controls. In conclusion, an appropriate amount of allicin can effectively alleviate LPS-induced damage by regulating oxidative stress, endoplasmic reticulum stress, cell apoptosis, inflammatory response, and the health of the intestine and liver. This study provides a scientific basis for the application of allicin in aquaculture and contributes to the development of healthy snakehead fish farming technology.

Environmental pH is a key factor affecting the nutritional quality of crayfish; its underlying mechanism remains unclear. This study preliminarily revealed the potential regulatory pathways underlying the effect of pH on the nutrient metabolism of crayfish through multi-omics analysis. The results showed that the contents of crude protein (18.03% vs. 16.82%), TAA (13.25% vs. 12.67%), and PUFA (55.38% vs. 45.02%) in crayfish under a high pH environment were significantly higher than those in the low pH group. Transcriptome analysis identified 1622 differentially expressed genes, among which the key gene glna was significantly upregulated. Metabolomics further revealed 181 differential metabolites, such as 2-phospho-d-glycerate and threonine, which were significantly enriched and jointly promoted the synthesis of flavor substances and amino acids. In contrast, multiple lipid-related metabolites (such as glycerone phosphate) and fat synthesis genes, such as fasn and acsl, were significantly downregulated in the low pH group, leading to reduced fatty acid content. Intestinal microbiota analysis indicated that the ratio of Firmicutes/Bacteroidota increased, and the abundance of Proteobacteria increased in the high pH group. At the genus level, the abundance of Bacilloplasma increased significantly. Some unclassified microbial groups in Rhodobacteraceae also showed enrichment. PICRUSt2 functional prediction revealed that these microbial taxa were significantly enriched in amino acid metabolism and other nutrient-related pathways, and their structural changes collectively promoted the accumulation of nutrients in the host. This study quantitatively explored the potential regulatory pathways through which the high pH environment may improve the flavor and nutritional value of crayfish at the molecular level.

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Nutrient stoichiometry is a pivotal yet underexplored driver of ecosystem function in Apostichopus japonicus pond mariculture during summer heat. A survey of seven ponds in Dalian (July 2022) combined multivariate ordination, hierarchical partitioning (HP), and structural equation modeling (SEM) to assess how nitrogen–phosphorus (N/P) dynamics regulate phytoplankton. Nutrient concentrations differed significantly among ponds (P < 0.05), with culture ponds exhibiting nitrogen enrichment (e.g., NH₄⁺-N 0.04 ± 0.03 mg/L in pond #7 vs 0.01 ± 0.01 mg/L in pond #3), while the control pond had higher phosphorus levels. Phytoplankton consisted of 18 species across two phyla, predominantly diatoms (95.5%), with dinoflagellates (4.5%) present only in ponds with balanced stoichiometry. Diversity indices varied widely (Simpson 0.1859–0.7189; Shannon 0.3884–1.4480), with lower values in high N/P ponds. Principal Coordinates Analysis (PCoA) indicated strong separation along N–P gradients (first two axes 87.49%). HP analysis showed that community variation was primarily driven by total nitrogen (TN) (57.91%), followed by N/P ratio (36.60%) and TN/TP ratio (5.29%). SEM analysis revealed TN as a central node (TN–TP  –0.60; TN–NH₄⁺-N  –0.25; TN–NO₂⁻-N 0.28; TP–PO₄³⁻-P 0.55). Together, nitrogen enrichment, phosphorus limitation, and bioturbation by sea cucumbers led to diatom-dominated, low-diversity states. Actionable N/P management strategies—optimized water quality biological regulation to reduce nitrogen loading, targeted phosphorus supplementation, and real-time stoichiometric monitoring—are proposed to stabilize communities and mitigate bloom risks.

Recognition of fish feeding intensity enables precision feeding, which is beneficial for enhancing economic returns and protecting the aquatic environment. Vision-based methods are often hindered by water turbidity and surface disturbances, while existing acoustic approaches face high cost, model complexity, and noise sensitivity. To address low-cost, lightweight, and robust requirements, we propose FTPG-CNN6, an improved Convolutional Neural Network (CNN) with Frequency-Time Attention (FT-Attention), Frequency-Prioritized convolution (FP-Conv), and GhostConv. Raw audio signals collected by low-cost hydrophones are processed to generate Mel-frequency cepstral coefficient (MFCC) feature maps, reducing data dimensionality while preserving key acoustic information. These feature maps are then input into the FTPG-CNN6 network, which incorporates the three modifications to enhance recognition: GhostConv to reduce computational cost, FP-Conv to capture critical frequency features and adapt to the uneven frequency distribution of signals collected by low-cost hydrophones, the FT-Attention mechanism to emphasize important regions and mitigate the impact of environmental noise. The resulting lightweight model is deployed on embedded devices, enabling real-time recognition of fish feeding intensity. On a self-built dataset, the method achieved 97.30% accuracy, outperforming EfficientNet and ResNet18 by 5.37% and 3.35%, respectively, while reducing memory use by 32.16% and 71.17%. These results demonstrate a low-cost, lightweight, and robust solution suitable for real-time fish feeding recognition, providing practical support for precision feeding.

The objective of this study was to evaluate the productive performance and expression levels of growth-related (IGF1, mTOR), lipid metabolism-related (FAS), and oxidative stress-related (hsp70) genes in Nile tilapia (Oreochromis niloticus) subjected to different feed restriction regimes in a biofloc-aquaponics system. The experiment included a restriction phase of 84 days with different feeding schedules (Control: daily; T1: 5 days of feeding/2 days of restriction; T2: 3 days of feeding/4 days of restriction; T3: 1 day of feeding/6 days of restriction), followed by a 28-day refeeding period. T1 showed the highest weight gain, and Specific Growth Rate (SGR), indicating complete compensatory growth. More severe restrictions resulted in lower Feed Conversion Ratio (FCR) values. Short-term restrictions did not significantly alter IGF1, mTOR, or hsp70 expression; however, long-term restrictions resulted in a marked downregulation of mTOR and an upregulation of hsp70 in treatments T2 and T3. Notably, FAS expression appeared responsive to moderate restriction. In basil plants (Ocimum basilicum), no significant differences were found in biometric variables or total phenolic content among treatments. Overall, the results indicate that moderate feed restriction can be applied in integrated biofloc–aquaponic systems without compromising fish survival or plant performance, while inducing distinct metabolic and physiological responses in Nile tilapia.

Hard clam (Meretrix taiwanica) aquaculture is one of the most important shellfish farming sectors in Taiwan, covering approximately 16,000 hectares and accounting for 40% of the nation’s aquaculture area. Pond management practices, including the use of animal manure and sediment tilling, strongly influence nutrient cycling and microbial processes during cultivation. Although clam shell formation involves calcium carbonate precipitation that releases CO₂, the net greenhouse gas balance of clam ponds remains poorly understood. This study monitored three brackish-water clam ponds in Taizi Village, Yunlin County, Taiwan, throughout 2024, measuring monthly fluxes of carbon dioxide (CO₂), methane (CH₄), nitrous oxide (N₂O) and related environmental parameters during both non-culture and culture periods. The ponds functioned as CO₂ sinks before stocking and after harvesting but became CO₂ sources during the culture stage. The ponds consistently acted as a CH₄ sink, but an N₂O source. The average fluxes were 1,126.88 ± 5,735.56 mg m⁻² day⁻¹ for CO₂, − 0.52 ± 1.06 mg m⁻² day⁻¹ for CH₄, and 0.88 ± 0.90 mg m⁻² day⁻¹ for N₂O. When expressed as CO₂-equivalents (GWP₁₀₀), CO₂ contributed 90% of total emissions, followed by N₂O (10%). These patterns likely reflect complex interactions among biological activity, microbial processes, alkalinity, and oxygen levels within the pond ecosystem. Overall, this study demonstrates that clam aquaculture can contribute to greenhouse gas emissions, underscoring the need for improved management strategies to mitigate environmental impacts.

Pond aquaculture is the predominant mode of freshwater aquaculture, where accurate assessment and early warning of future water quality are essential for effective management and the healthy growth of cultured species. Most current studies focus on water quality prediction but face challenges, including the limitations of single-factor models, the high cost of multi-factor models, and insufficient attention to dynamic early warning. This study proposes a dynamic early warning approach combining a parallel CNN-GRU fusion model with an Improved Comprehensive Water Quality Identification Index (ICWQII). The method utilizes the parallel CNN-GRU model to simultaneously predict multiple water quality parameters. A game theory-based algorithm optimizes empirical, objective, and prediction-error weights to derive dynamic comprehensive weights, which are then integrated with the ICWQII to evaluate future water quality levels. Notably, the model features a lightweight architecture containing only 0.15 million parameters, with a single-sample forward inference computational cost of approximately 0.23 MFLOPs. The proposed method achieved an accuracy of 0.8241 and a missing alarm rate (MAR) of 0.1104 on the constructed dataset. The results demonstrate that the proposed method balances lightweight characteristics with accuracy, enabling proactive water quality warning. This lays a foundation for extension to diverse aquaculture environments and species, providing technical support for intelligent water quality regulation.

The Chinese mitten crab Eriocheir sinensis, mainly farmed in ponds, often uses snails as natural bait. The accumulation of feces, bait remnants, and nitrogenous organic matter at the pond bottom can result in elevated ammonia nitrogen concentrations in E. sinensis ponds. To evaluate the effects of ammonia nitrogen stress on the foraging behavior and metabolic physiology of crabs, we implemented three experimental treatments with distinct ammonia nitrogen concentrations (0, 5, and 10 mg·L⁻¹) in the laboratory. The foraging behavior of E. sinensis was monitored using a crab behavior monitoring setup, and physiological indices were measured at the end of the experimental period. The results indicate that as the concentration of ammonia nitrogen increases in the water of aquaculture pond, the predation rate of crabs is significantly reduced. Consistent patterns were observed in three main behavioral components: handling time proportion, the probability of capture upon encounter, and consumption upon capture. These findings highlight the critical role of these behaviors in mediating the adverse effects of ammonia nitrogen on the predation efficiency of E. sinensis. The crustacean hyperglycemic hormone and glucose levels in the hemolymph and the oxygen consumption rate of crabs increased significantly, while hemocyanin decreased with the elevated ammonia nitrogen. Elevated concentrations of ammonia nitrogen in water result in increased energy expenditure for E. sinensis, while simultaneously reducing their predation rate. Consequently, the physiological and biochemical alterations induced by high ammonia nitrogen levels, combined with the decline in predation efficiency, represent one of the primary factors contributing to reduced pond aquaculture productivity of E. sinensis. This study not only provides a theoretical basis for understanding the behavioral and physiological regulatory mechanisms of crustaceans under ammonia nitrogen stress, but also offers important references for water quality management practices in the healthy cultivation of E. sinensis.