Aquacultural Engineering最新文献

{"title":"Investigation of aeration process in rotating disk ceramic membranes for aquaculture wastewater purification","authors":"Jun Zhang ,&nbsp;Jingjing Yao ,&nbsp;Guofeng Cheng ,&nbsp;Fang Wang ,&nbsp;Shouqi Cao ,&nbsp;Xingguo Liu ,&nbsp;Qinsong Hu","doi":"10.1016/j.aquaeng.2025.102542","DOIUrl":"10.1016/j.aquaeng.2025.102542","url":null,"abstract":"<div><div>To enhance the separation efficiency of particles in the rotating ceramic membrane aeration process, this study employs the Eulerian two-fluid model and the Population Balance Model (PBM) to numerically simulate the gas-liquid two-phase flow within the reaction zone of the aeration device. The accuracy of the numerical calculation model is validated by comparing bubble diameters at different monitoring planes. The study investigates the impacts of different aeration rates, bubble diameters, and ceramic membrane rotational speeds on the characteristics of the two-phase flow field. The results are as follows: As the aeration rate increases, in the top part of the aeration tank, the water flow velocity and turbulence dissipation rate are relatively low, which is conducive to improving the flotation efficiency. When the aeration rate reaches 10 m³/h, the velocity and turbulent dissipation rate decreased significantly. When the bubble diameter is 20 μm, the velocity non-uniformity index inside the aeration tank is the lowest. When the bubble diameter increases to 100 μm, the water flow velocity and turbulence dissipation rate near the ceramic disc are at their minimum. As the rotational speed of the ceramic membrane increases from 30 r/min to 60 r/min, the flow field velocity and turbulence dissipation rate gradually decrease, while the gas content near the ceramic membrane increases significantly.</div></div>","PeriodicalId":8120,"journal":{"name":"Aquacultural Engineering","volume":"110 ","pages":"Article 102542"},"PeriodicalIF":3.6,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143815847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of a novel sterilized thin-film photobioreactor for efficient microalgae cultivation by mixotrophic mode","authors":"Bocheng Su ,&nbsp;Jianke Huang ,&nbsp;Jinzhe Zhang ,&nbsp;Le Cao ,&nbsp;Ruizeng Zhang ,&nbsp;Haolong Wang ,&nbsp;Xiwen Xue ,&nbsp;Xiaoyu Wang","doi":"10.1016/j.aquaeng.2025.102539","DOIUrl":"10.1016/j.aquaeng.2025.102539","url":null,"abstract":"<div><div>Microalgae-assisted aquaculture has recently garnered significant attention due to the potential of microalgae as feed additives, immunostimulants, and for water quality management in aquaculture systems. To achieve high productivity of algal biomass, there is an urgent need for efficient and cost-effective photobioreactors (PBRs) for microalgae cultivation. In the present study, a novel sterilized thin-film photo-bioreactor (STFPBR) was developed that allows for various trophic modes of microalgal culture. The gas distributor and operational conditions of the STFPBR were optimized accordingly. The results demonstrated that the biomass of <em>C. pyrenoidosa</em> achieved with a coarse sand gas distributor was 42.21 % higher than that obtained using a nano-ceramic gas distributor. The optimal light intensity provided to the STFPBR for microalgae growth was 120 μmol m⁻² s⁻¹, while increasing the light intensity to 160 μmol m⁻² s⁻¹ did not result in any significant difference in biomass concentration. The oxygen content of the air (∼21 %) was sufficient for <em>C. pyrenoidosa</em> growth under mixotrophic conditions. The increased oxygen content in the aeration gas negatively affected microalgae growth. In comparison to photoautotrophic cultivation, utilizing mixotrophic and heterotrophic modes resulted in an over two-fold increase in algal biomass yields. Nevertheless, heterotrophically grown microalgae exhibited the lowest protein content (39.72 %) and chlorophyll concentration (10.24 mg g⁻¹). Conversely, exposure to light during mixotrophic cultivation significantly enhanced both algal protein content (47.87 %) and chlorophyll concentration (16.10 mg g⁻¹). Overall, our findings highlight the pioneering development of STFPBR system designed for efficient and convenient cultivation of microalgae.</div></div>","PeriodicalId":8120,"journal":{"name":"Aquacultural Engineering","volume":"110 ","pages":"Article 102539"},"PeriodicalIF":3.6,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143792822","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental and numerical investigations on hydrodynamic response of vessel-shaped semi-submersible aquacultural platform","authors":"Xiaodong Bai ,&nbsp;Zhuang Lu ,&nbsp;Hanbing Luo ,&nbsp;Mingren Guo ,&nbsp;Can Yang","doi":"10.1016/j.aquaeng.2025.102540","DOIUrl":"10.1016/j.aquaeng.2025.102540","url":null,"abstract":"<div><div>The vessel-shaped semi-submersible aquacultural platform gains increasing attention in the aquacultural industry due to the high biomass production and structural strength. Understanding the dynamic characteristics is essential for structural optimization and operational efficiency. This study presents numerical and experimental analyses of the hydrodynamic responses of the vessel-shaped semi-submersible aquacultural platform under wave actions. In the experiments, the vessel-shaped semi-submersible aquacultural platform was modeled with a scale ratio of 1:32. Both regular and random wave tests are carried out in head seas and beam seas. The numerical simulation model of the vessel-shaped semi-submersible aquacultural platform is developed to investigate motion and mooring load characteristics. The time-domain model is formulated based on the potential theory for floating structures, the screen model for nets and the lumped-mass point for mooring lines. The aquacultural platform motions and mooring forces are numerically simulated and compared with the experimental results. The response time-series, spectra, and the statistics are compared, indicating that the proposed numerical model successfully predicts motions and mooring forces. Experimental and numerical results from both regular and random wave tests suggest that the platform experiences slight rotation motions. Different nets with different solidities are utilized to analyze the effect of the nets. The nets have limited influence on the motions of the aquacultural platform.</div></div>","PeriodicalId":8120,"journal":{"name":"Aquacultural Engineering","volume":"110 ","pages":"Article 102540"},"PeriodicalIF":3.6,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143792819","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of feed pellet buoyancy and stocking ratio of tilapia on fish and natural food in carp-tilapia polyculture ponds","authors":"Morgina Akter ,&nbsp;Johan W. Schrama ,&nbsp;Mohammad Mamun Ur Rashid ,&nbsp;Marc Verdegem","doi":"10.1016/j.aquaeng.2025.102537","DOIUrl":"10.1016/j.aquaeng.2025.102537","url":null,"abstract":"<div><div>Enhancing the growth of high value fish species in pond polyculture can benefit farmers economically, but tools to feed species in ponds differently are still not available. A factorial design with three types of pellet buoyancy (100 % floating pellets, 50 %–50 % mixture of floating and sinking pellets (on weight basis) and 100 % sinking pellets) and two stocking ratios of tilapia (SRT) ( equal (rohu:catla:silver carp:tilapia ratio = 1:1:1:1) and low (rohu:catla:silver carp:tilapia ratio = 3:3:3:1) were applied. Results show that pellet buoyancy influences fish biomass gain and survival (P &lt; 0.01) by influencing inter- and intra-specific competition. Feeding a 50 %–50 % mixture of floating and sinking pellets proved to be the best strategy benefitting survival and biomass gain of all fish species. Fish performance was significantly less when feeding 100 % sinking pellets and intermediate at feeding 100 % floating pellets. A low stocking ratio of tilapia improved carp production but decreased total fish production (P &lt; 0.05). Pellet buoyancy did not alter the natural food availability in the ponds while stocking ratio of tilapia negatively influenced plankton and benthos availability (P &lt; 0.05). Thus a low stocking ratio of tilapia and feeding a 50 %–50 % mixture of floating and sinking pellets are the best strategies to enhance carp production in carp-tilapia polyculture ponds. Depending on farmers intention, tilapia production can be enhanced by increasing its stocking density and further by feeding a mix of floating and sinking pellets to carp-tilapia polyculture systems.</div></div>","PeriodicalId":8120,"journal":{"name":"Aquacultural Engineering","volume":"110 ","pages":"Article 102537"},"PeriodicalIF":3.6,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143760981","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pesticide residues in aquatic products: sources, advances in detection technologies, and risk management","authors":"Zhen Liang ,&nbsp;Zhimei Liu ,&nbsp;Shiqi Fang ,&nbsp;Xiangfeng Shen ,&nbsp;Wenjuan Wang ,&nbsp;Shuming Wang","doi":"10.1016/j.aquaeng.2025.102536","DOIUrl":"10.1016/j.aquaeng.2025.102536","url":null,"abstract":"<div><div>Pesticide residues in aquatic products are a growing food safety issue worldwide, originating from aquaculture practices, agricultural runoff with legacy pesticides, and industrial effluents with new contaminants. This review examines gaps in understanding the combined effects of multiple pesticides and the challenges in detecting emerging contaminants like neonicotinoids and fungicides in aquatic samples. It covers the sources of pesticide contamination, bioaccumulation of organochlorines, organophosphates, and pyrethroids in aquatic organisms, and their harmful effects on ecosystems (e.g., toxicity, reproduction issues, neurological damage, and biodiversity loss) and human health (e.g., poisoning, endocrine disruption, developmental problems, and possible cancer risks). The review highlights gas chromatography-mass spectrometry (GC-MS) for detecting volatile compounds and liquid chromatography-tandem mass spectrometry (LC-MS/MS) for analyzing a broad range of pesticides as key methods. It also discusses faster, cost-effective options like immunoassays and biosensors for field testing. Risk management strategies focus on reducing pesticide use in agriculture and aquaculture, improving process controls, and monitoring residues against Maximum Residue Limits (MRLs), alongside consumer education for better awareness. The review points out unresolved issues, such as the long-term impacts of new pesticides and their combined effects, and suggests future research on multi-residue detection, risk assessment combining ecological and health factors, portable testing tools, and sustainable aquaculture practices to ensure safe aquatic food supplies.</div></div>","PeriodicalId":8120,"journal":{"name":"Aquacultural Engineering","volume":"110 ","pages":"Article 102536"},"PeriodicalIF":3.6,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143768676","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The influence of length–width ratio of an unconventional mobile finfish structure on the drag force and dissolved oxygen: Laboratory experimentation and Computational Fluid Dynamics (CFD)","authors":"Duc Nguyen ,&nbsp;Si Thu Paing ,&nbsp;Sarah Wakes ,&nbsp;Ross Vennell ,&nbsp;Scott Rhone ,&nbsp;Louise Kregting ,&nbsp;Suzy Black","doi":"10.1016/j.aquaeng.2025.102538","DOIUrl":"10.1016/j.aquaeng.2025.102538","url":null,"abstract":"<div><div>Open ocean aquaculture (OOA) offers a number of benefits from inshore aquaculture, such as stronger currents and waves enhancing the water quality. However, conventional static aquaculture systems deployed in the open ocean do not resolve environmental issues such as the effects of heatwaves, or physical challenges such as extreme wave action. Farming fish in a mobile or semi-mobile system would have the advantage of being able to move fish to the best conditions for the fish year-round. The current study proposes an unconventional fin fish structure that could be deployed in the open ocean on either a single-point mooring (fixed), or as a fully mobile (mobile) system. The body of the structure is a square cross-section cylinder shape, covered by water-proof woven fabric cloth, and nets placed at the front and back of the body. This study considers how adjusting the length–width ratio, influences drag forces (important for a mobile scenario) as well as the dissolved oxygen (DO) inside the structure (important for a fixed scenario). This was achieved using flume experiments and Computational Fluid Dynamics (CFD). The volume of the structure is kept at 10,000 m³, current speed at 0.1 m/s and fish stocking density is 30 kg/m³ with the length–width ratio varying from 1 to 6. We found that when the length–width ratio increased, this resulted in the decrease of drag force and an increase of the unhealthy volume fraction (i.e. DO &lt; 70 % of ambient DO) inside the structure, and vice versa. We also found that speed reduction caused by bio-fouling results in an increase of drag force and unhealthy volume fraction. Therefore, it is recommended that the design of mobile structures should balance the demands of the fish as well as the fish farmers which will be dependent on the operation (fixed or mobile).</div></div>","PeriodicalId":8120,"journal":{"name":"Aquacultural Engineering","volume":"110 ","pages":"Article 102538"},"PeriodicalIF":3.6,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143734814","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fish mass estimation method based on adaptive parameter tuning and disparity map restoration under binocular vision","authors":"Lu Zhang ,&nbsp;Yapeng Zheng ,&nbsp;Zunxu Liu","doi":"10.1016/j.aquaeng.2025.102535","DOIUrl":"10.1016/j.aquaeng.2025.102535","url":null,"abstract":"&lt;div&gt;&lt;div&gt;Accurately estimating fish mass is crucial for evaluating fish growth status, enabling precise feeding, and improving aquaculture efficiency. In current aquaculture, invasive measurements may cause certain damage to fish and affect their healthy growth, non-invasive measurements mostly use stereo cameras to capture fish images and extract two-dimensional and three-dimensional features for mass estimation. The calculation of three-dimensional fish features relies on the acquisition of accurate disparity maps. Most current disparity maps are obtained through manual tuning of algorithmic parameters, which not only increases labor and time costs but also introduces a degree of randomness. To address the above problems, a fish mass estimation method based on Adaptive Parameter Tuning-Disparity Map Restoration (APT-DMR) and Multiple Linear Regression (MLR) under binocular vision technology is proposed. Firstly, fish images are obtained using a binocular camera, followed by camera calibration and image correction. Secondly, image processing technologies are used to segment the corrected image to obtain the fish target, and the two-dimensional features of the fish target are extracted. On this basis, the method based on APT-DMR is adopted to obtain the fish disparity map, extract the corresponding key matching points of the left and right images of the fish, and calculate the coordinates of the three-dimensional spatial feature points using the triangular transformation principle, achieving the extraction of the three-dimensional features of the fish target. Finally, fish mass is predicted using the MLR method. Based on the binocular vision technology, the APT-DMR method is employed to obtain the fish disparity map, which realizes the extraction and calculation of the three-dimensional features of the fish. The proposed method effectively addresses the problem that the traditional algorithm needs to constantly tune the parameters to obtain an accurate disparity map. Additionally, a new feature, the fish depth ratio, is introduced to enrich the model representation, and finally, the fish mass is successfully predicted. In addition to saving time and labor costs, the proposed method also effectively eliminates the stress and potential damage to the fish caused by invasive mass measurements. The crucian carp were taken as the experimental object and the proposed method was tested on the real dataset. The results show that the mean absolute error (MAE) is 0.0061, the root mean square error (RMSE) is 0.0084, and the coefficient of determination (R&lt;sup&gt;2&lt;/sup&gt;) is 0.9338. Compared with Polynomial Regression (PR)-Weight, Decision Tree Regression (DTR)-Weight, Random Forest Regression (RFR)-Weight, Back-Propagation Neural Network (BPNN)-Weight, and Support Vector Regression (SVR)-Weight mass estimation methods, the performance of each evaluation metric of the proposed method has been greatly improved, predicting the fish mass more accurately.&lt;/div&gt;&lt;/di","PeriodicalId":8120,"journal":{"name":"Aquacultural Engineering","volume":"110 ","pages":"Article 102535"},"PeriodicalIF":3.6,"publicationDate":"2025-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143679974","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Group activity amount estimation for fish using multi-object tracking","authors":"Yiran Liu ,&nbsp;Beibei Li ,&nbsp;Liegang Si ,&nbsp;Chunhong Liu ,&nbsp;Daoliang Li ,&nbsp;Qingling Duan","doi":"10.1016/j.aquaeng.2025.102534","DOIUrl":"10.1016/j.aquaeng.2025.102534","url":null,"abstract":"<div><div>The activity amount of fish can directly indicate its level of health. Quantitative indexes of fish activities provide valuable data for water quality control, disease warning, and fish behavior research, which can enhance factory breeding technology and fish welfare. To address the issue of a lack of indicators for the amount of activity in fish groups and individuals, a group activity amount estimation method based on fish multi-object tracking is proposed in this paper. The FasterNet network is improved by incorporating a branch that learns the features from the previous frame. This method is referred to as Improved FasterNet Fish Tracking (IFFT), and is capable of fast and accurate identification, location, and estimation of the offset of fishes between the two frames in a joint way. Subsequently, a method of activity amount estimation based on grid step is proposed to get the activity index from the trajectories. Moreover, a visualization method is proposed to illustrate the spatial distribution of fish groups. This method utilizes elliptic fitting to calculate the spatial distribution characteristics such as radius, dispersion, cohesion, and polarization. Experiments conducted on the established fish tracking dataset demonstrate that the proposed IFFT achieved a high-order tracking accuracy (HOTA) of 67.54 % and a multi-object tracking accuracy (MOTA) of 92.4 %, surpassing other existing mainstream methods. Furthermore, the average tracking speed reached 20.6 frames per second (FPS). The mean absolute percentage error (MAPE) of the activity amount estimation of fish groups based on the grid step is 0.15 % per frame, indicating a highly accurate estimation of fish activity. The results demonstrate that the proposed activity estimation method of fish groups based on multi-object tracking effectively eliminates the interference caused by water movement. It also achieves a balance between speed and accuracy, enabling real-time quantitative and visual analysis of fish group movement and providing decision support for improving the factory farming process.</div></div>","PeriodicalId":8120,"journal":{"name":"Aquacultural Engineering","volume":"110 ","pages":"Article 102534"},"PeriodicalIF":3.6,"publicationDate":"2025-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143679977","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multi-objective optimization of inlet and outlet in a circular culture fish tank using the GBDT-NSGAII algorithm and computational fluid dynamic","authors":"Shanhong Zhang ,&nbsp;Guanghui Yu ,&nbsp;Yu Guo ,&nbsp;Yang Wang ,&nbsp;Daoliang Li ,&nbsp;Xiaoli Zhao ,&nbsp;Dannie D. O'Brien ,&nbsp;Jui-Che Chiang","doi":"10.1016/j.aquaeng.2025.102532","DOIUrl":"10.1016/j.aquaeng.2025.102532","url":null,"abstract":"<div><div>In a circular culture tank, hydrodynamics plays an essential role for the growth and development of aquatic products in the recirculating aquaculture system (RAS). The challenge of maintaining the maximum effective energy utilization rate and achieving uniform velocity distributions remains a significant hurdle. To solve this problem, a novel multi-objective optimization approach was employed, utilizing the Gradient Boosting Decision Tree-Non-Dominated Sorting Genetic Algorithm II (GBDT-NSGAII) algorithm, to optimize the parameters of inlet and outlet of culture tanks as achieving suitable hydrodynamics. Specifically, the initial circular tank is regarded as the benchmark, four vital parameters of circular tank including nozzle quantities, nozzle diameters, outlet diameters, and inlet angles has been investigated by CFD model. The development of a GBDT-NSGA-II-based model and parameter optimization is conducted to obtain the Pareto front, with the objective of maximizing effective energy utilization rate while minimizing velocity STD. The main results show that: 1) At an inlet velocity of 0.5 m/s, the benchmark successfully establishes dynamic homogeneous velocity fields, while exhibiting a highly pressurized domain in the inlet pipe primarily influenced by the nozzle diameter. 2) The GBDT model demonstrates excellent predictive capability for the CFD database, with an RMSE of 0.002 m/s for average velocity and an RMSE of 0.304 % for velocity STD.3) The diameter of nozzles (12.76 mm) and the number of nozzles (7) have a highly significant influence on both average velocity and velocity uniformity compared to the benchmark model among the 63 groups of optimal Pareto fronts. 4) The optimal inlet-outlet parameter combination mainly includes an inlet velocity of 0.49 m/s and an outlet diameter of 22.26 mm, which improves the energy utilization rate up to 88 % compared to the benchmark model. The GBDT-NSGA-II model, driven by CFD simulation dataset, can effectively replace complex CFD calculations and save computer resources, exhibit commendable performance in accurately predicting the hydrodynamics of circular culture tanks in RAS.</div></div>","PeriodicalId":8120,"journal":{"name":"Aquacultural Engineering","volume":"110 ","pages":"Article 102532"},"PeriodicalIF":3.6,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143632176","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A high-precision and lightweight underwater fish detection and recognition approach based on the improved YOLOX-nano algorithm","authors":"Mengtian Li ,&nbsp;Xiaorun Li ,&nbsp;Shuhan Chen ,&nbsp;Hui Huang","doi":"10.1016/j.aquaeng.2025.102533","DOIUrl":"10.1016/j.aquaeng.2025.102533","url":null,"abstract":"<div><div>In the past few years, the aquaculture industry has experienced a growing demand for in-situ fish detection using live videos from underwater observatory platforms to autonomously monitor cultivated fish and assess their health and growth conditions. To achieve the ideal balance between model size and detection precision, this paper offers a lightweight YOLOX-based fish detection and recognition approach termed Foc_YOLOXn_ASFF. In this study, we introduce Focal loss as a substitute for the binary cross-entropy (BCE) loss utilized by the original YOLOX to train the objectiveness branch, aiming to alleviate the class imbalance between the background and foreground classes. Meanwhile, we focus on moderating the inconsistency across various feature scales by combining YOLOX-nano with the adaptively spatial feature fusion (ASFF) structure to better fuse multi-scale features. Foc_YOLOXn_ASFF remarkably boosts the AP by over 3.6 % from 0.846 to 0.877 compared with the original YOLOX-nano through the implementation of Focal loss and ASFF structure. Foc_YOLOXn_ASFF achieves superior performance with 0.877 AP but only 2.27 M parameters, outperforming the counterparts YOLOv5n and SE_YOLOv5s_DGhost by 1.2 % AP and 7.9 % AP respectively. Extensive experimental findings indicate that Foc_YOLOXn_ASFF for both model size and detection precision is capable of meeting the requirements of practical applications on embedded devices with limited computational resources.</div></div>","PeriodicalId":8120,"journal":{"name":"Aquacultural Engineering","volume":"110 ","pages":"Article 102533"},"PeriodicalIF":3.6,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143679975","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}