Aquacultural Engineering最新文献

{"title":"Numerical study on the flow characteristics of an integrated fish cage based on the monopile offshore wind turbine foundation","authors":"Guo-Hai Dong ,&nbsp;Shou-An Guo ,&nbsp;Chun-Wei Bi","doi":"10.1016/j.aquaeng.2024.102458","DOIUrl":"10.1016/j.aquaeng.2024.102458","url":null,"abstract":"<div><p>The integration of net cages and offshore wind turbines can effectively develop and utilize marine resources and is one of the important ways of intensive use of the sea. The numerical simulation of the hydrodynamics of an integrated fish cage based on the monopile offshore wind turbine foundation in currents is carried out. The realizable <em>k-ε</em> model is adopted and the porous media model is used to simulate the net. To verify the validity of the numerical model, the numerical result is compared with the data of the corresponding literature. The results show that the numerical method is effective. On this basis, the flow field distribution results of the integrated structure at different velocities are calculated. At the center of the downstream zone of the integrated structure, the time-average velocity is lower than 80 % of the initial velocity. The effects of the net solidity and the cage draught on the flow field characteristics of the integrated structure are analyzed. The results show that the increase of net solidity will significantly reduce the velocity inside the net cage and in the downstream zone of the cage. As the net solidity increases from 0.14 to 0.32, the average velocity attenuation inside the net cage increased by 13.9 %. The change of cage draught will affect the velocity distribution in the horizontal and vertical directions. When the cage draught increases, the velocity on both sides in the downstream zone of the integrated structure increases more than 5 %. It is expected that the results of this study can provide data support for the design of integrated structure of net cages and offshore wind turbines.</p></div>","PeriodicalId":8120,"journal":{"name":"Aquacultural Engineering","volume":"107 ","pages":"Article 102458"},"PeriodicalIF":3.6,"publicationDate":"2024-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141997845","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":"Post-smolt Atlantic salmon can regulate buoyancy in submerged sea-cages by gulping air bubbles","authors":"Luke T. Barrett ,&nbsp;Lars-Thomas Unneland Larsen ,&nbsp;Samantha Bui ,&nbsp;Tone Vågseth ,&nbsp;Erlend Eide ,&nbsp;Tim Dempster ,&nbsp;Frode Oppedal ,&nbsp;Ole Folkedal","doi":"10.1016/j.aquaeng.2024.102455","DOIUrl":"10.1016/j.aquaeng.2024.102455","url":null,"abstract":"<div><p>Salmon lice (<em>Lepeophtheirus salmonis</em>) are the most severe health challenge facing Atlantic salmon (<em>Salmo salar</em>) aquaculture. Infestations threaten farmed and wild salmonids, drive up production costs, and limit industry growth. Submersible sea-cages can reduce infestation pressure by holding salmon below the surface layers where lice larvae are most abundant. However, submergence leads to loss of buoyancy over time, as salmonids must periodically refill their swim bladders by gulping air. Pockets of air held at depth within ‘air domes’ enable salmon to gulp air, but air domes are large and unwieldy structures. A more intuitive solution may be to deliver a stream of air bubbles at depth, as bubbling is commonly used in sea-cages to promote vertical mixing, and salmon interact with these bubbles. Here, we conducted a pilot study to test whether newly sea-transferred salmon would use bubbles for buoyancy regulation. We conducted 3 trials in sequence, each involving 15–19 days of continuous submergence, and recorded buoyancy-related behaviors in 1 cage with full surface access, 1 cage submerged without air, and 2 cages submerged with air bubbling. Bubbling was provided continuously in the first two trials, before being reduced to 90 min day⁻¹ in the third trial. Salmon submerged with bubbling maintained their swim bladder volume and swimming speed at similar levels to the cage with full surface access throughout all trials, indicating that they successfully refilled using bubbles. The same parameters deteriorated in salmon in the cage submerged without air. Acclimation to bubbles took ∼3 days whether at the surface or after submergence, indicating that several days of bubbling before submergence may be beneficial. Some fish accumulated fluid in the swim bladder during submergence (more severe in fish submerged without bubbling). Together, the results suggest that bubbling can improve outcomes for salmon undergoing prolonged submergence. Moreover, bubbling offers an alternative to air domes that is less technically demanding, provides a greater spatial distribution of air, and supports welfare through behavioral enrichment.</p></div>","PeriodicalId":8120,"journal":{"name":"Aquacultural Engineering","volume":"107 ","pages":"Article 102455"},"PeriodicalIF":3.6,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0144860924000669/pdfft?md5=48300a994a81cf330357c8cf51921459&pid=1-s2.0-S0144860924000669-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141991271","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":"Experimental investigation on the convey performance and control strategy of a special annular jet pump for deep sea feeding","authors":"Xiao Chen,&nbsp;Shengtong Wang,&nbsp;Xuwang Wang,&nbsp;Kai Chen,&nbsp;Huifeng Su,&nbsp;Musheng Chen","doi":"10.1016/j.aquaeng.2024.102454","DOIUrl":"10.1016/j.aquaeng.2024.102454","url":null,"abstract":"<div><p>This research conducted an experimental investigation on an annular jet pump (AJP), designed specifically for deep sea feeding used 0–30 m underwater, through building an experimental prototype of an underwater hydraulic conveying system. The experiment established relationships between the limit cavitation point, pressure ratio, flow rate ratio, pump efficiency, and secondary flow rate with the working water state and pump outlet pressure. Furthermore, the optimal efficiency control strategy and the optimal secondary flow control strategy of the AJP for the underwater hydraulic feeding system were formulated, and the respective characteristics were compared. The feed pellets two-phase conveying experiment was also conducted to investigate changes from conveying water only in the limit cavitation point and secondary flow rate. Both water only and feed pellet conveying in AJP will approach the limit cavitation state, and the flow rate ratio will stop changing when the pressure ratio of the AJP is less than a certain value. These results offer an experimental basis and control reference for the design and construction of an adaptive-water-depth hydraulic feeding system for deep sea aquaculture.</p></div>","PeriodicalId":8120,"journal":{"name":"Aquacultural Engineering","volume":"107 ","pages":"Article 102454"},"PeriodicalIF":3.6,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141953859","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 use of automatic belt feeders in a Penaeus vannamei pilot scale super-intensive nursery and grow-out with biofloc system","authors":"Dariano Krummenauer ,&nbsp;Otávio Augusto Lacerda Ferreira Pimentel ,&nbsp;Aline Bezerra ,&nbsp;Fernando Henrique Gonçalves ,&nbsp;Luís Henrique Poersch ,&nbsp;Wilson Wasielesky Jr.","doi":"10.1016/j.aquaeng.2024.102453","DOIUrl":"10.1016/j.aquaeng.2024.102453","url":null,"abstract":"<div><p>This study aimed to evaluate the effect of using automatic belt feeders (BF) on water quality, growth of <em>Penaeus vannamei</em>, and partial budget in super-intensive pilot scale systems with biofloc technology. A nursery phase (2300 shrimp m⁻²) and a grow-out phase (400 shrimp m⁻²) were carried out with the following feeding management strategies, all with three repetitions: T1: by hand, T2: by hand + BF12h; T3: BF24h. In the nursery, a spike in total ammonia concentration was observed in the first weeks of the trial in treatment T1, possibly due to nutrients from uneaten feed. Nitrite was higher in T1 treatment than in T2 and T3. Nitrate was lower in the treatment T1 than in T2 and T3. At the grow-out trial, nitrite was higher in treatment T1 than in T2 and T3. These results indicated a slower nitrification process in T1 and more efficient in treatments where automatic feeders were used since an accumulation of nitrate was observed throughout the trials and low concentrations of nitrite were observed both in the nursery and the grow-out. In the nursery and the grow-out, the T3 treatment had a higher final weight and a lower feed conversion ratio. Furthermore, the T3 treatment had a higher yield than the T1 treatment. Treatment T3 had the highest net benefit/cost, considering the entire production cycle (nursery and grow-out). Our results strongly indicate that using automatic belt feeders allows an improvement in water quality, promotes shrimp growth, improves yield, reduces feed use, and improves the net benefits in <em>P. vannamei</em> super-intensive nursery and grow-out with biofloc systems.</p></div>","PeriodicalId":8120,"journal":{"name":"Aquacultural Engineering","volume":"107 ","pages":"Article 102453"},"PeriodicalIF":3.6,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141961830","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 method for counting fish based on improved YOLOv8","authors":"Zhenzuo Zhang ,&nbsp;Jiawei Li ,&nbsp;Cuiwen Su ,&nbsp;Zhiyong Wang ,&nbsp;Yachao Li ,&nbsp;Daoliang Li ,&nbsp;Yingyi Chen ,&nbsp;Chunhong Liu","doi":"10.1016/j.aquaeng.2024.102450","DOIUrl":"10.1016/j.aquaeng.2024.102450","url":null,"abstract":"<div><p>In industrial aquaculture, accurately counting fish in real-time is crucial for optimizing feeding strategies, preventing disease, and managing water quality. Current methods utilizing sensors, acoustics, machine learning, and density map regression face challenges such as high costs, invasiveness, and computational complexity. To address these limitations, we propose the YOLOv8n-MEMAGD method for accurate real-time fish counting. This method enhances YOLOv8 by incorporating the GELU activation function, MPDIoU for localization loss, and the C2f-FAM and C2f-MSCA modules into the backbone network. Additionally, the neck network is redesigned with a gather-and-distribution mechanism. Experimental results under land-based industrial aquaculture conditions demonstrate that YOLOv8n-MEMAGD achieved a mean absolute error (MAE) of 2.28 and a root mean square error (RMSE) of 2.84, even in challenging conditions such as fish overlap, aggregation, and background confounding. Compared to YOLOv8n, the proposed method increased average precision (AP50) for fish detection by 6.2 %, and significantly reduced MAE and RMSE by 61.4 % and 65.2 %, respectively, compared to CSRNet. Additionally, the method achieved a frame rate of 61 frames per second (FPS) when the number of fish ranged from 79 to 91, representing a 390.4 % increase over CSRNet. By comparing heatmaps, the proposed method demonstrates more effective detection of fish edge contours than current advanced algorithms. In conclusion, the proposed method shows promise for application in aquacultural scenarios with higher turbidity and larger number of fish.</p></div>","PeriodicalId":8120,"journal":{"name":"Aquacultural Engineering","volume":"107 ","pages":"Article 102450"},"PeriodicalIF":3.6,"publicationDate":"2024-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141961829","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":"Method for layout optimization of coastal cage aquaculture systems in Southeast Asia","authors":"Roberto Mayerle ,&nbsp;José M. Fernández Jaramillo ,&nbsp;Ketut Sugama ,&nbsp;Poerbandono ,&nbsp;Kadir Orhan","doi":"10.1016/j.aquaeng.2024.102438","DOIUrl":"10.1016/j.aquaeng.2024.102438","url":null,"abstract":"<div><p>This paper presents the development of a generally applicable method for the layout optimization of coastal cage aquaculture systems in Southeast Asia. The method combines data from the authors’ spatial-planning methodology with results of water quality modelling and an optimization technique based on genetic algorithms. This study successfully demonstrates the method's effectiveness for a target aquaculture site in northwest Bali, Indonesia. Optimum siting and sizes of fish farms to maximize fish production and promote fish growth while securing environmental sustainability are delivered for the site in Bali. The results of the application for several fish farming sizes show that by proper fish farming layout, environmentally sustainable fish production on the western channel of the site in Bali could rise tremendously with respect to the current operating conditions. Fish farm clusters with 256 cages are found to be best suited to the western channel. The method has broad applicability, can be upscaled to new sites, and can be used to assess, expand, and optimize currently operating sites.</p></div>","PeriodicalId":8120,"journal":{"name":"Aquacultural Engineering","volume":"106 ","pages":"Article 102438"},"PeriodicalIF":3.6,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0144860924000499/pdfft?md5=0c9e4b78e4e0739fa463517fa74acd87&pid=1-s2.0-S0144860924000499-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141688724","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":"Determination of early breeder in goldfish (Carassius auratus Linn.) with learning vector quantization, probabilistic and pattern recognition neural networks","authors":"Taşkın Değirmencioğlu ,&nbsp;Uğur Erkin Kocamaz","doi":"10.1016/j.aquaeng.2024.102441","DOIUrl":"10.1016/j.aquaeng.2024.102441","url":null,"abstract":"<div><p>It is common practice to categorize growing fish according to quality in fish farming centers. For such an application, experienced and estimating people are needed. By pre-selecting the right fish for the ornamental fish industry, it gets ahead of the competitors. This study deals with the classification of early breeder determination in goldfish using three different Artificial Neural Network (ANN) techniques. This classification model can help the fish industry assess classification risks and make the right decision. The used dataset was derived from the results of the classification section of 120 goldfish. It consisted of 7 input parameters (day, live weight, body length, head height, head width, body height, and current class). During trial, all goldfish fed by a diet contained 360 g crude protein and 4449.85 kcal metabolizable energy (kg / dry matter). The important types of classification ANNs, namely Learning Vector Quantization Neural Network (LVQNN), Probabilistic Neural Network (PNN), and Pattern Recognition Neural Network (PRNN) were employed for the machine learning scheme. The training and test performances of the ANN models were compared with the correct prediction ratio. They showed that all of the proposed ANN techniques were well at classification. However, the PRNN model was better than the LVQNN and PNN as a classifier for the breeder selection of goldfish. Therefore, the results of PRNN model such as histogram, Receiver Operating Characteristic (ROC) curve, regression, confusion matrix, accuracy, sensitivity, precision, and F₁ score were given and discussed. Furthermore, the classification of early breeder determination in goldfish were examined for days with the best PRNN.</p></div>","PeriodicalId":8120,"journal":{"name":"Aquacultural Engineering","volume":"106 ","pages":"Article 102441"},"PeriodicalIF":3.6,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141853006","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":"Appling machine learning for estimating total suspended solids in BFT aquaculture system","authors":"Érico Tadao Teramoto ,&nbsp;Wilson Wasielesky ,&nbsp;Dariano Krummenauer ,&nbsp;Guilherme Wolff Bueno ,&nbsp;Danilo Cintra Proença ,&nbsp;Carlos Augusto Prata Gaona","doi":"10.1016/j.aquaeng.2024.102439","DOIUrl":"10.1016/j.aquaeng.2024.102439","url":null,"abstract":"<div><p>Biofloc Technology (BFT) systems are used to improve water quality and the production of aquatic organisms, and they influence dissolved oxygen, alkalinity, and pH, directly affecting the efficiency and success of this production system. Measuring total suspended solids (TSS) in water demands substantial investments and involves a time-consuming process to obtain results. This delay in obtaining results poses a significant challenge to the operations of these farms. In this study, we applied Artificial Neural Networks (ANN) and Support Vector Machine (SVM) methods based on artificial intelligence and water quality parameters (easy to measure, low cost, and quick response) to identify the most accurate method for measuring TSS. The best TSS estimate was achieved with SVM using nitrite and turbidity as predictive variables, which tended to overestimate the real value by 19 %, presenting a potential for application in estimating TSS in the BFT aquaculture system.</p></div>","PeriodicalId":8120,"journal":{"name":"Aquacultural Engineering","volume":"106 ","pages":"Article 102439"},"PeriodicalIF":3.6,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141708233","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":"Chlorella vulgaris cold preservation (4∘C) as a means to stabilize biomass for bioreactor inoculation: A six-month study","authors":"Victor Pozzobon ,&nbsp;Wendie Levasseur ,&nbsp;Cristobal Camarena-Bernard","doi":"10.1016/j.aquaeng.2024.102449","DOIUrl":"10.1016/j.aquaeng.2024.102449","url":null,"abstract":"<div><p><em>Chlorella vulgaris</em> cells were maintained over six months (or tentatively) using three protocols: two-week subculturing (positive control), storage at 4^∘C, and simple abandonment (negative control). Cultures were monitored by their optical and cell densities over the trial period. Cells were characterized by their size, pigment profile, photosystem II status (OJIP test), electron transport rate assay (light curve), and lag phase duration when regrown. The abandoned cultures quickly showed cells deviating from their nominal state (increased size, a loss of their pigments, a negative alteration of their photosynthetic capacity, and an extended lag phase when inoculated into fresh medium). Frequent subculturing yielded reasonably stable performances. Yet, our experience showed that uncontrollable factors (human errors, lack of communication between teams) could expose the cultures to unfortunate incidents. 4^∘C preservation allowed the cells to have a constant size and a slightly increased, yet stable, pigment profile associated to a dark acclimation (+12 % total chlorophyll). Finally, regrowth tests demonstrated that 4^∘C preservation induces slightly improved performance (lag phase duration reduced by 9.5 %) than frequent subculturing. Those findings advocate for the use of 4^∘C preservation to reduce cell maintenance work and conserve a pool of cells in a similar state to be used as repeatable inoculum for larger-scale experiments while nullifying otherwise batch-to-batch variation effects. Subculturing work can be reduced from once every two weeks to once every six months at least.</p></div>","PeriodicalId":8120,"journal":{"name":"Aquacultural Engineering","volume":"107 ","pages":"Article 102449"},"PeriodicalIF":3.6,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0144860924000608/pdfft?md5=bb28e93cac379baa6f50a4532b47fd0d&pid=1-s2.0-S0144860924000608-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141951792","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":"A descriptive study of carbon dioxide production and removal in full-scale RAS for Atlantic Salmon (Salmo salar L.) post-smolt: A comparison of two different measurement methods for CO2","authors":"Leila Jafari ,&nbsp;Sveinung Fivelstad ,&nbsp;Kari Attramadal ,&nbsp;Håkon Flataker ,&nbsp;Pernille Mjaatvedt ,&nbsp;Anne Berit Olsen ,&nbsp;Melissa Chierici ,&nbsp;Camilla Diesen Hosfeld","doi":"10.1016/j.aquaeng.2024.102442","DOIUrl":"10.1016/j.aquaeng.2024.102442","url":null,"abstract":"<div><p>Reliable data on metabolic rates and CO₂ removal efficiency are essential for fish welfare in intensive production and RAS design. This descriptive study at a commercial post-smolt production facility evaluates two full-scale land-based RAS with different salinity levels: Module1 (M1) (2.5 ± 0.46‰ salinity) and Module2 (M2) (13.6 ± 0.46‰ salinity, with two separate RAS units, M2-RAS1, and M2-RAS2). Over eight weeks, water quality parameters were monitored in different places in the systems. CO₂ concentrations were measured with an OxyGuard probe and calculated from total inorganic carbon (TIC). As fish biomass and feed load increased in both modules over time, CO₂ concentrations increased and pH decreased, despite bicarbonate addition. In M1, CO₂ levels increased from 6.2 to 16.4 mg L⁻¹, while in M2, levels remained between 3.5 and 7.2 mg L⁻¹. Apparent CO₂ production, calculated from TIC, averaged at 5.2 ± 0.93 mg CO₂ kg fish⁻¹ min⁻¹ in M1, and 3.2 ± 1.25 and 4.0 ± 1.45 mg CO₂ kg fish⁻¹ min⁻¹ in M2-RAS1 and M2-RAS2 respectively. At the same time, the theoretical CO₂ production rates showed a value of 4.4 ± 0.73, 4.2 ± 0.38, and 3.9 ± 0.71 mg CO₂ kg fish⁻¹ min⁻¹ in M1, M2-RAS1, and M2-RAS2 respectively. The theoretical feed-to-CO₂ conversion weight-to-weight ratio was estimated to be 0.345. However, M1 exhibited a higher measured feed-to-CO₂ conversion ratio of 0.418, while M2-RAS1 and M2-RAS2 displayed ratios of 0.261 and 0.346, respectively. Observed CO₂ (%) removal changed from 40% to 54% in M1, from 17% to 46% in M2-RAS1, and 26–44%, in M2-RAS2 over the observation period. This study suggests a significant role of the moving bed biofilter in CO₂ removal, however, the effect size varied during the study and between modules, warranting further investigation. On average, 38% of CO₂ removal before the degasser occurred within the biofilter in M1, and 49% in both RAS systems in M2. The total carbonate levels fluctuated over time, making it challenging to determine a clear increase or decrease, likely due to manual and varying bicarbonate additions. The two methods for assessing CO₂ generally revealed minor differences and need more assessment. The prevalence of nephrocalcinosis was significantly more pronounced in M1 (73%), than in M2 (11%), which could be related to the difference in the CO₂ level between the fish tanks. This study provides valuable insights into CO₂ dynamics that may be useful in RAS design and operation for optimizing water quality and fish welfare.</p></div>","PeriodicalId":8120,"journal":{"name":"Aquacultural Engineering","volume":"107 ","pages":"Article 102442"},"PeriodicalIF":3.6,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0144860924000530/pdfft?md5=a71a6f95b4574ded76d1a87c2b28469b&pid=1-s2.0-S0144860924000530-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141848946","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}