Aquacultural Engineering最新文献

{"title":"Influence of raceway based biofloc system on the growth and physiological responses of Penaeus vannamei and GIF tilapia in a polyculture model – BFT aquaculture system","authors":"M Joshna ,&nbsp;Ahilan B ,&nbsp;Cheryl Antony ,&nbsp;Ravaneswaran K ,&nbsp;Chidambaram P ,&nbsp;Uma A ,&nbsp;Ruby P ,&nbsp;Prabu E ,&nbsp;Somu Sunder Lingam R","doi":"10.1016/j.aquaeng.2024.102463","DOIUrl":"10.1016/j.aquaeng.2024.102463","url":null,"abstract":"<div><p>The present study investigates the efficiency of raceway-based biofloc technology for the production of <em>Penaeus vannamei</em> and Genetically Improved Farmed tilapia in a polyculture model. Six raceway tanks were used to explore the growth performance, digestive enzyme activities, bacterial count and histology of <em>P. vannamei</em> reared with GIF tilapia using raceway-based biofloc and clear water raceway culture systems. Each raceway (6.8 m x 2.2 m x 3 m) was stocked with 60 shrimp/m³ of <em>P. vannamei</em> (0.93±0.09 g), and 5 fish/m³ of GIF tilapia (0.42±0.01 g) and reared for 90 days. Biofloc, with a carbon: nitrogen ratio of 15:1, is developed and maintained using soyahull pellet powder as organic carbon source, with continuous aeration was provided. The present study found significantly higher weight gain of <em>P. vannamei</em> (16.09±0.26 g) and GIF tilapia (11.71±0.35 g) in raceway-based biofloc culture system. Survival of <em>P. vannamei</em> and GIF tilapia did not exhibit any significant variations between raceway-based biofloc and clear water raceway systems. Significantly higher digestive enzymes activities of protease (0.25±0.01 and 0.14±0.02 U/ mg protein/min), lipase (0.88±0.04 and 0.37±0.01 U/ mg protein/min) and amylase (0.008±0.00 and 0.0016±0.00 U/ mg protein/min) are recorded in <em>P. vannamei</em> and GIF tilapia in raceway-based biofloc culture system, respectively. Higher values of total heterotrophic bacteria (52.25±0.88×10⁴ CFU/ml, 49.63±1.10 ×10⁷ CFU/g and 53.12±0.44×10⁷ CFU/g) and bacillus counts (76.50±0.46×10² CFU/ml, 155.62±0.89×10² CFU/g and 238.75±0.82×10² CFU/g) are recorded in culture water, <em>P.vannamei</em> gut and GIF tilapia gut in raceway based biofloc culture system, respectively. No histopathological changes are observed in the GIF tilapia (gut), <em>P. vannamei</em> (gut and hepatopancreas), but deformities such as congestion of the tips of few secondary lamellae are noticed in the GIF tilapia (gill) reared in the clear water raceway system. Therefore, the study suggests that polyculture of <em>P. vannamei</em> and GIF tilapia in a raceway-based biofloc system is advantageous over the clear water raceway system in terms of production augmentation with improved physiological conditions.</p></div>","PeriodicalId":8120,"journal":{"name":"Aquacultural Engineering","volume":"107 ","pages":"Article 102463"},"PeriodicalIF":3.6,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142229627","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":"Insights into different marine aquaculture infrastructures from a life cycle perspective","authors":"Lorenzo Rossi ,&nbsp;Michele Zoli ,&nbsp;Fabrizio Capoccioni ,&nbsp;Domitilla Pulcini ,&nbsp;Arianna Martini ,&nbsp;Jacopo Bacenetti","doi":"10.1016/j.aquaeng.2024.102462","DOIUrl":"10.1016/j.aquaeng.2024.102462","url":null,"abstract":"<div><p>Aquaculture facilities represent an often-neglected process in environmental impact studies. This study focus on the environmental impact assessment of alternative net materials in Mediterranean marine aquaculture. A Life Cycle Assessment was conducted using primary and secondary data from specific databases and literature. Three baseline scenarios were compared: copper alloy net cages with 100 % of recycled material (CAN100), 75 % of recycled material (CAN75), and polyethylene net (PEN) System boundaries include manufacturing and disposal of cages, nets, and mooring system. The use and emissions of antifouling paints and CAN were considered. Sensitivity analysis of the most impacting sub-processes and Uncertainty analysis were also conducted. The use of CAN is advantageous in terms of environmental impact, but only considering a complete recyclability of the net at the end of its service life. Moreover, when considering a reduced service life of the PEN due to the detrimental effect of biofouling, the advantage of the CAN is even more evident. To counteract the negative effect of biofouling, copper-based antifouling paints are generally used in marine aquaculture. These products are a main environmental hotspot in PEN systems. Therefore, a higher consumption of such products could determine an environmental burden shifting from CAN to PEN ones. So far, CAN are not widespread in the aquaculture industry, mainly due to the high cost of initial investment compared to traditional PEN. Considering operational and environmental advantages, CAN cages could represent an affordable and resilient solution for aquaculture enhancing environmental, economic, and social performances of this industry.</p></div>","PeriodicalId":8120,"journal":{"name":"Aquacultural Engineering","volume":"107 ","pages":"Article 102462"},"PeriodicalIF":3.6,"publicationDate":"2024-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0144860924000736/pdfft?md5=722130f4d2e1dbac3c28ff9c5f689ecc&pid=1-s2.0-S0144860924000736-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142095078","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":"Evaluating the suitability of nitrate-nitrogen levels for post-smolt Atlantic salmon Salmo salar production in RAS with assistance from heart rate bio-loggers","authors":"John Davidson,&nbsp;Curtis Crouse,&nbsp;Christine Lepine,&nbsp;Christopher Good","doi":"10.1016/j.aquaeng.2024.102461","DOIUrl":"10.1016/j.aquaeng.2024.102461","url":null,"abstract":"<div><p>Previous onsite research determined that post-smolt Atlantic salmon <em>Salmo salar</em> growth, health, and welfare were unaffected by exposure to 99 mg/L nitrate-nitrogen (NO₃-N) in freshwater recirculating aquaculture systems (RAS). A subsequent study was conducted to determine if higher concentrations negatively impact Atlantic salmon within a similar size range. Salmon production metrics were compared in triplicate RAS with NO₃-N levels increasing from 100 to 250 mg/L (“high”) vs. 50–100 mg/L NO₃-N (“low”). An average feed loading rate of 2.53 kg feed/m³ makeup water/day was maintained to facilitate natural NO₃-N accumulation up to 75–100 mg/L, and sodium nitrate was continuously dosed to achieve higher concentrations. All-female diploid and all-female triploid Atlantic salmon were comingled in six replicated RAS, resulting in 227 fish/tank with an initial mean weight of 0.35 kg. Six diploid salmon with surgically implanted heart rate bio-loggers were included in each RAS. Continuously logged heart rates were matched with frequently measured NO₃-N levels to determine the onset of a physiological response. At the end of the 6-month study, salmon exposed to the high and low NO₃-N conditions weighed 1.84 ± 0.05 and 1.91 ± 0.02 kg, respectively (<em>p</em> &gt; 0.05). Diploid and triploid salmon growth rates, feed conversion ratios, maturation prevalence, survival, fin condition, and cataract scores were unaffected (<em>p</em> &gt; 0.05). However, salmon heart rates were generally higher in the high NO₃-N treatment after concentrations exceeded 150 mg/L NO₃-N. Higher plasma chloride, hematocrit, and hemoglobin levels (<em>p</em> &lt; 0.05) consistent with an adaptive response to a stressor were also measured in salmon from the high NO₃-N RAS during this period. These findings suggest that NO₃-N concentrations &lt; 150 mg/L do not affect post-smolt Atlantic salmon under similar operating conditions, including freshwater RAS without denitrification technologies and water hardness &gt;300 mg/L as CaCO₃. Additional research is required to determine if higher NO₃-N concentrations are suitable for Atlantic salmon production over longer exposure periods and with naturally produced NO₃-N levels imparted by reduced water exchange. Feed- and nitrogen-loading rates conducive to maintaining the tested NO₃-N levels are reported.</p></div>","PeriodicalId":8120,"journal":{"name":"Aquacultural Engineering","volume":"107 ","pages":"Article 102461"},"PeriodicalIF":3.6,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0144860924000724/pdfft?md5=6d9027fb4f30b4a5cbb38f7925426706&pid=1-s2.0-S0144860924000724-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142077500","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":"The impact of shade net use on total nitrogen removal by duckweed (Lemna perpusilla) at different levels of catfish farming effluent","authors":"Agus Waluyo ,&nbsp;Awalina Satya ,&nbsp;Kukuh Nirmala ,&nbsp;Yuni Puji Hastuti ,&nbsp;Tjandra Chrismadha ,&nbsp;Evi Susanti ,&nbsp;Wardah Wardah","doi":"10.1016/j.aquaeng.2024.102456","DOIUrl":"10.1016/j.aquaeng.2024.102456","url":null,"abstract":"<div><p>Duckweed (Lemna perpusilla) has been shown to reduce nutrient levels in aquaculture effluent, particularly total nitrogen, which can be caused by a variety of organic contaminants in water. Duckweed biomass is an important source of bioenergy and phytoremediation in aquaculture. This aspect makes it a viable solution for sustainable integrated aquaculture, although appropriate duckweed biomass development is critical to its success and long-term survival. Duckweed growth, as an autotroph, is controlled by two factors: nutrition and sunlight. The aquaculture production cycle changes nutrient content in medium culture based on feed, fish age, and density, while weather influences solar radiation. The study aims to investigate duckweed growth response and phytoremediation capacity by analyzing changes in catfish farming waste-water quality grouped by fish age (L1: 2 months, L2: 3 months, and L3: 4 months) and shade net treatment at 25 % sunlight blocking (N25), 50 % (N50), and no shade net (N0). The experiment was carried out in triplicate in a semi-outdoor growth system placed in a greenhouse. It comprised of three series of duckweed culture containers filled with catfish farming wastewater, each with a working volume of 50 L. A total of 48 duckweed culture containers were floated inside a series of Recirculating Aquaculture System (RAS) tanks. Biomass harvesting and water quality monitoring were done every three days for a period of 18 days. N25 had the highest biomass weight, productivity, and average TN elimination efficiency, with values of 225.21 ± 140.04 g, 50.05 ± 10.06 g/(m².d), and 61.94 ± 8.01 %, respectively (P &lt; 0.05). The N0 values were 190.80 ± 117.52 g, 42.40 ± 9.29 g/(m².d), and 55.61 ± 6.85 % (P &lt; 0.05). The lowest values observed in N50 were 72.27 ± 55.70 g, 16.06 ± 4.90 g/(m².d), and 51.67 ± 4.10 % (P &lt; 0.05). This study proved the optimal duckweed growth and TN removal effectiveness with N25 under varying light intensity, allowing for the long-term use of duckweed in waste management and integrated aquaculture.</p></div>","PeriodicalId":8120,"journal":{"name":"Aquacultural Engineering","volume":"107 ","pages":"Article 102456"},"PeriodicalIF":3.6,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142087320","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":"Settling velocity and effective density analysis for aquaculture floc particles: An approach through bivariate parametric copula","authors":"Boris Miguel López-Rebollar ,&nbsp;Ricardo Arévalo-Mejía ,&nbsp;Carlos Díaz-Delgado ,&nbsp;Shahid Latif ,&nbsp;Taha B.M.J. Ouarda","doi":"10.1016/j.aquaeng.2024.102459","DOIUrl":"10.1016/j.aquaeng.2024.102459","url":null,"abstract":"<div><p>The study of flocs' characteristics in aquaculture tanks remains challenging due to their complex composition. Nevertheless, the application of experimental methods, such as particle tracking velocimetry (PTV), has made it possible to measure particle diameters and settling velocities. With the experimental data, bivariate distribution functions through copula modelling were employed to provide a more accurate estimation of the effective density of flocs through the empirical model proposed by Lau and Krishnappan. It was observed that the primary particle density constituting the flocs varied between 1051 kg/m³ and 1426 kg/m³. Moreover, when considering a variable primary particle density, effective floc density values ranging from 980 kg/m³ to 1500 kg/m³ were obtained for floc diameters ranging from 0.068 mm to 1.9 mm, respectively. This variation confirms that the <em>b</em> and <em>c</em> parameters of the Lau-Krishnappan model change for each floc diameter range following the quantiles associated with the conditional probability of diameter and settling velocity. Thus, employing copula approximation, a more accurate fit of the Lau-Krishnappan model was achieved, considering a wide range of particle diameters at the tails. This approach offers better estimates of floc effective density and settling velocity, essential for enhancing the selection and design of aquaculture tanks and settlers to ensure efficient solids removal.</p></div>","PeriodicalId":8120,"journal":{"name":"Aquacultural Engineering","volume":"107 ","pages":"Article 102459"},"PeriodicalIF":3.6,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142040056","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":"CLIP-FSSC: A transferable visual model for fish and shrimp species classification based on natural language supervision","authors":"Kanyuan Dai ,&nbsp;Ji Shao ,&nbsp;Bo Gong ,&nbsp;Ling Jing ,&nbsp;Yingyi Chen","doi":"10.1016/j.aquaeng.2024.102460","DOIUrl":"10.1016/j.aquaeng.2024.102460","url":null,"abstract":"<div><p>Fish and shrimp species classification is a practical need in the field of aquaculture. Traditional classification method includes extracting modal features of the single image and training them on downstream datasets. However, this method has the disadvantage of requiring manual annotated image data and significant training time. To address these issues, this paper introduces a method named CLIP-FSSC (Contrastive Language–Image Pre-training for Fish and Shrimp Species Classification) for zero-shot prediction using a pre-trained model. The proposed method aims to classify fish and shrimp species in the field of aquaculture using a multimodal pre-trained model that utilizes semantic text description as an image supervision signal for transfer learning. In the downstream fish dataset, we use natural language labels for three types of fish - grass carp, common carp, and silver carp. We extract text category features using a transformer and compare the results obtained from three different CLIP-based backbones for the image modality - vision transformer, Resnet50, and Resnet101. We compare the performance of these models with previous methods that performed well. After performing zero-shot predictions on samples of the three types of fish, we achieve similar or even better classification accuracy than models trained on downstream fish datasets. Our experiment results show an accuracy of 98.77 %, and no new training process is required. This proves that using the semantic text modality as the label for the image modality can effectively classify fish species. To demonstrate the effectiveness of this method on other species in the field of aquaculture, we collected two sets of shrimp data - prawn and cambarus. Through zero-shot prediction, we achieve the highest classification accuracy of 92.00 % for these two types of shrimp datasets. Overall, our results demonstrate that using a multimodal pre-trained model with semantic text description as an image supervision signal for transfer learning can effectively classify fish and shrimp species with high accuracy, while reducing the need for manual annotation and training time.</p></div>","PeriodicalId":8120,"journal":{"name":"Aquacultural Engineering","volume":"107 ","pages":"Article 102460"},"PeriodicalIF":3.6,"publicationDate":"2024-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142039948","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":"Environmental impact of different Mediterranean technological systems for European sea bass (Dicentrarchus labrax) and Gilthead sea bream (Sparus aurata) farming","authors":"Michele Zoli ,&nbsp;Lorenzo Rossi ,&nbsp;Baldassare Fronte ,&nbsp;Joël Aubin ,&nbsp;Christophe Jaeger ,&nbsp;Aurelie Wilfart ,&nbsp;Carlo Bibbiani ,&nbsp;Jacopo Bacenetti","doi":"10.1016/j.aquaeng.2024.102457","DOIUrl":"10.1016/j.aquaeng.2024.102457","url":null,"abstract":"<div><p>As at a global level, the aquaculture sector is growing in Italy too and, among the various species, European sea bass and Gilthead sea bream are becoming increasingly important. As a consequence, the environmental implications are an emerging issue and in-depth studies on the topic of farm sustainability are needed. This study compared the environmental performance of four specialised Sea bass and Sea bream farms in Italy, characterized by different technological system, using the Life Cycle Assessment approach. 1 tonne of fish biomass harvested and 1 kg of fish protein were chosen as functional units. The 'from cradle to gate' perspective was applied to define the system boundaries. The results revealed that land-based farms had higher environmental impacts compared to coastal farm with a Climate change of 9660 and 7250 kg CO₂ eq for the former and 2443 and 3308 for the latter. Despite the use of aquafeeds emerged as a significant contributor of environmental impacts across all farms (with a share of more than 80 % of the Climate change in the coastal farms), even energy and liquid oxygen consumption, particularly on land-based farms, played a crucial role (with impact shares of 25–40 % in climate change). A sensitivity analysis on energy sources revealed that the use of more renewable energy can reduce the Climate Change of land-based farms by an average of 5 %, while an all-biodiesel fleet has a beneficial effect on particulate matter (-7.5 %) and acidification (-6 %) on coastal farms. The study provided a comprehensive overview of the environmental impact of Italian ESB and GSB production. In addition, highlighted areas for further research, including biofouling mitigation, optimization of energy consumption, and exploration of alternative oxygenation methods in land-based farms.</p></div>","PeriodicalId":8120,"journal":{"name":"Aquacultural Engineering","volume":"107 ","pages":"Article 102457"},"PeriodicalIF":3.6,"publicationDate":"2024-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142049055","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":"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}