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The genus Jannaschia is one of the representatives of aerobic anoxygenic phototrophic (AAP) bacteria, which is a strictly aerobic bacterium, producing a photosynthetic pigment bacteriochlorophyll (BChl) a. However, a part of the genus Jannaschia members have not been confirmed the photosynthetic ability. The partly presence of the ability in the genus Jannaschia could suggest the complexity of evolutionary history for anoxygenic photosynthesis in the genus, which is expected as gene loss and/or horizontal gene transfer. Here a novel AAP bacterium designated as strain AI_62T (= DSM 115720 T = NBRC 115938 T), was isolated from coastal seawater around a fish farm in the Uwa Sea, Japan. Its closest relatives were identified as Jannaschia seohaensis SMK-146 T (95.6% identity) and J. formosa 12N15T (94.6% identity), which have been reported to produce BChl a. The genomic characteristic of strain AI_62T clearly showed the possession of the anoxygenic photosynthesis related gene sets. This could be a useful model organism to approach the evolutionary mystery of anoxygenic photosynthesis in the genus Jannaschia. Based on a comprehensive consideration of both phylogenetic and phenotypic characteristics, we propose the classification of a novel species within the genus Jannaschia, designated as Jannaschia pagri sp. nov. The type strain for this newly proposed species is AI_62T (= DSM 115720 T = NBRC 115938 T). [ABSTRACT FROM AUTHOR]

Clean energy captured by offshore wind turbines has been widely used for supporting onshore activities. In the near future, facilities such as offshore wind turbines can also play an important role in the energy transition of offshore activities. Offshore wind energy can be employed for electrifying operations in offshore fish farms, which are traditionally supplied by diesel-engine barges/generators. Based on this motivation, this study focuses on the design of a shared mooring system between a semi-submersible offshore fish cage and a spar-type floating wind turbine. A numerical model of the proposed shared mooring system is implemented in a global response analysis software SIMA for performing fully coupled time-domain simulations. The configuration of the shared mooring line is determined using an engineering approach, which comprises Irvine's formulation, system eigenvalue analysis, and cost estimation. Moreover, relevant case studies by altering the environmental conditions are performed. Extreme operational conditions that may give large relative motions are investigated thoroughly. The dynamic performance of the integrated system is compared with that of individual structures. The global motion of the floating wind turbine and its mooring line's tension behavior are obviously influenced by the existence of the shared line. In general, the present work investigates the feasibility of a shared mooring system for these types of offshore structures and further gives insights into the engineering design procedure. [ABSTRACT FROM AUTHOR]

This paper presents results of the research and developing of a modular floating aquaculture platform based on inland river cargo barge design to be exploited under biosecurity and sustainability conditions in the Lower Danube region, aligned with the current sustainable development strategies of the blue economy outlined by the European Union. The new design combines the capabilities of growing fish in modular tanks with the growing vegetables in recirculating systems in the greenhouse superstructure of the floating platform. The first step of this interdisciplinary and multidisciplinary research is a full naval architecture study, meaning both aerodynamically and strength calculation, as a starting point for the design and evaluation of the growing fish and cultivating vegetables systems.

Aquaculture has emerged as the most rapidly growing technology for food production on a global scale. The current growth trajectory of aquaculture production surpasses that of all other meat production types and is anticipated to persist in its ascent with the continuous expansion of the agriscience industry. The contribution of aquaculture to food security varies based on species and country, either directly through domestic consumption or indirectly through the stimulation of economic growth via exports. In Türkiye, the share of aquaculture in overall production has increased over the years and has become a significant contributor to the country's economic development through exports. Fish farms concentrated in the Eastern Black Sea and Southern Aegean regions also draw attention due to their proximity to sea areas with intense maritime activities. Potential marine pollution in these regions poses a serious risk to these economically important resources, making it crucial to predict the extent of this risk in advance and take preventive measures. This study aims to simulate, through a scenario, how a possible oil spill in the Southern Aegean region would spread in the sea, how quickly it would reach the fish farms in this region, and how long it would take to impact the fish population to a certain extent. The values derived from this simulation will shed light on intervention plans to be implemented by both local and central authorities, serving as exemplary models for formulating similar plans for all aquaculture resources. [ABSTRACT FROM AUTHOR]

Tambaqui production is commonly performed in fertilized ponds, considering that this species feeds from zooplankton throughout its life. This study evaluated plankton's participation in the production of tambaqui juveniles in ponds using different stocking densities. A total of 72,000 fish (1.9 ± 0.01 cm and 0.4 ± 0.1 g) were stocked in 12 ponds (600 m2), in the densities of 5, 10, or 15 fish.m−2, with four replicates in a completely randomized design. Fish were fed twice a day to the point of satiety, with a commercial diet containing 36% of crude protein for 56 days. Zootechnical performance parameters were evaluated, and limnological variables were monitored. With the aid of stable isotopes, both the diet and plankton participation were assessed in the produced biomass of fish. Turbidity and Secchi were the only limnological variables that varied due to stocking density, while final biomass and final average density were the only zootechnical indexes that presented differences. Plankton contributed to the formation of muscles throughout the production period, with an average participation of 22.75 ± 12.82%. [ABSTRACT FROM AUTHOR]

Background: Aeromonas species is one of the most important causes of diseases in Clarias gariepinus, a public health threat with significant economic losses. Objectives: In this research, the prevalence and variety of Aeromonas species isolated from C. gariepinus cultured in an earthen pond were investigated, as well as the antibiogram and multiple antibiotic resistance index Methods: Aeromonas species were isolated by culture and biochemical test and confirmed using a Microbact 24E kit. The antibiotic susceptibility to 10 antibiotics was determined using the Kirby-Bauer disk diffusion method. Results: Aeromonas species were isolated with a prevalence of 43.1% with 4 different phenospecies with the highest prevalence of 46(24 %) for Aeromonas hydrophila followed by 15(7.8%) for Aeromonas caviae, then 10(5.2%) for Aeromonas veronii sobria, and the least was observed for Aeromonas veronii veronii 6(3.1%). The Aeromonas species showed high resistance to amoxicillin, ampicillin, colistin sulfate, oxytetracycline, trimethoprim/sulfamethoxazole, and penicillin, with varying resistant patterns, and the multiple antibiotic resistance index values ranged between 0.20 and 0.80. Conclusion: There was a diversity of Aeromonas species associated with multiple antibioticresistant leading to the wide spread of antimicrobial resistance. Therefore, there is a need to control the use of antibiotics and ensure the effective use of biosecurity and preventive management measures in fish farms. [ABSTRACT FROM AUTHOR]

The growing interest in the fish farming industry is driven by the depletion of natural fish stocks in the market. However, intensive aquaculture systems, which involve raising fish in artificial tanks and cages, can lead to challenges such as low-quality fish and increased mortality rates, depending on the species being cultivated. To address these issues and maximize yield, this paper proposes a fish quality monitoring system with automatic correction. The system focuses on monitoring and maintaining critical water quality parameters essential for fish growth, including temperature, water level, and pH level. The system comprises an Arduino connected to sensors and a web-based application for data collection and monitoring. Correction devices such as an aquarium heater, a valve, and a water pump are integrated into the system to maintain these parameters at optimal levels for fish development. To assess the system's efficiency and reliability, two fish monitoring setups were compared: one using the proposed controlled system and the other using a traditional setup. Results indicate that the controlled system increased efficiency, reduced stress on fish farmers, decreased fish mortality rates, and improved product quality compared to the traditional setup.

This study aimed to investigate the growth performance of far eastern catfish (Silurus asotus) on outdoor fish farms to obtain basic data for the domestic eastern catfish aquaculture industry. An outdoor fish farm was directly monitored from June 2018 to October 2019 to determine the farming conditions, growth performance, and water quality. The growth performance in 2017 was analyzed using data from the same fish farm. Three years of monitoring showed that the fish farm required approximately 5–6 months between stocking, harvesting, and selling an S. asotus batch. The growth parameters, namely, the weight gain rate (WGR), specific growth rate (SGR) for culture periods, SGR for feeding periods, and feed coefficient rate (FCR), were 4,664.7%, 1.27%, 2.43%, and 1.25 in 2017; 6,452.0%, 1.52%, 2.79%, and 1.42 in 2018; and 3,270.0%, 1.11%, 2.12%, and 1.38 in 2019, respectively. Moreover, the WGR was two-fold higher in 2018 than 2019, whereas the FCR was more effective in 2019 than 2018, presumably because of the stocking density. No mass mortality was observed during the water quality analysis. The results of this study provide basic data for the development of the catfish industry.

Fish species distribution in Lake Lebedinoye is considered. The samples were collected by fry seine along entire coast of the lake. Ten species of fish were sampled in the coastal zone; juveniles of chum salmon Oncorhynhus keta, amur stickleback Pungitius sinensis, and japanese dace Tribolodon hakonensis were rather abundant, other species were few in number. Japanese huchen Parahucho perryi were noted among the latter species: both juveniles of different age and an adult specimen of ≈ 2 kg weight were caught.

Aquaculture is becoming a strategic sector for many national economies to supply the increasing demand for fish from consumers. Fish culture conditions and processing operations can lead to an increase in microbial contamination of farmed fish that may shorten the shelf-life of fish products and byproducts, and ready-to-eat fishery products. The objective of this study was to evaluate the hygienic-sanitary status of water, environment, and processing of fresh-farmed rainbow trout (Oncorhynchus mykiss) fillets produced in a local fish farm in Andalusia, Spain. To achieve this, a longitudinal study was carried out by collecting environmental (air and food-contact surfaces), water from fish ponds, and rainbow trout samples. Thereby, seven sampling visits were performed between February 2021 and July 2022, where foodborne pathogens and spoilage microorganisms, together with physicochemical parameters, were analysed in the collected samples. Further, microbial identification of microbiota was achieved through a culture-dependent technique using blast analysis of 16S RNA gene sequencing. The results showed that Listeria monocytogenes and Salmonella were not detected in the analysed samples. Regarding the hygienic-sanitary status of the fish farm, the slaughtering bath, the eviscerating machine and the outlet water from fish ponds presented the highest counts of coliforms, Enterobacteriaceae, and Aerobic Mesophilic Bacteria. Staphylococcus aureus and sulphite-reducing Clostridium were identified in the conveyor belts, fish flesh, and viscera. The 16S RNA identification confirmed the presence of viable spoilage bacteria such as Citrobacter gillenii, Macrococcus caseolyticus, Hafnia paralvei, Lactococcus lactis, Lactococcus cremoris, Klebsiella, Escherichia coli, Morganella morganii, and Shewanella. Three of these genera (Citrobacter, Hafnia, and Pseudomonas) were present in all types of samples analysed. The results evidenced potential transmission of microbial contamination from contaminated packaging belts and boxes, evisceration and filleting machines to flesh and viscera samples, thus the establishment of control measures should be implemented in fish farm facilities to extend the shelf-life of farmed fishery products. [ABSTRACT FROM AUTHOR]

This research work was conducted as well as the determination of the resistance to antibiotics of these isolated species of E. coli in Nineveh governorate to assess the incidence of Escherichia coli (E. coli) contamination in different fish farms and local fish markets. The total number of fish samples used in the present study was 153, including 75 samples from various fish farms and 78 samples from different local markets in Mosul. The current study showed that the percentage of E. coli isolated from fish farms was 24% (18/75) and 35.9% (28/78) from local markets. While it showed a positive result for E. coli with serotype (O157:H7) with a percentage was 9.3 and 14.1% from both farmed fish and market fish samples, respectively. Additionally, all E. coli positive isolates possess the specific uidA gene, which was detected using the PCR technique. The highest sensitivity of E. coli bacteria to the antibiotic’s ciprofloxacin, trimethoprim, and gentamicin was 96, 94, and 86%, respectively. At the same time, the highest percentage of resistance of E. coli to the antibiotics cephalothin, tetracycline, erythromycin, and amoxicillin was 100, 64, 64, and 62%, respectively. To reduce health risks to consumers, these results provide useful basic information for the proper management of these environments in order to prevent fecal contamination in fish farms and the fish sold in local markets.

The water quality of Sheshroodbar River in Savadkooh was studied with population indices of benthic macroinvertebrates through sampling in 12 intervals at five stations in three replications, along with measuring some physicochemical parameters during 2014-2015. Among the invertebrates of the river (16 families from seven orders and six classes, n = 5230), aquatic insects larvae had the highest diversity. Significant differences were found between EPT and EPT/CHIR indices at different stations (p ≤ 0.05), but Shannon and Hilsenhoff indices were not significantly different among stations (p ≥ 0.05). Diptera at stations 1 and 2 and Diptera, Ephemeroptera, and Trichoptera at station 3 (n = 202, 256, & 282, respectively) showed the highest annual mean abundance. Mean annual frequency of orders was maximum for Haplotaxida, Tubificida, Lmbricida, Lumbriculida, Oligochaeta and Ephemeroptera at station 4, and for Trichoptera at station 5. The highest (12.3 ± 0.11) and the lowest (1.66 ± 0.24) annual averages of the Shannon-Wiener index were estimated for stations 1 and 4, respectively. The annual water quality was found to be very good (3.99 ± 0.18) to moderate (5.21 ± 0.21) from station 1 to station 3 (upstream to middle stations). Annual water quality was relatively poor (6.11 ± 0.34) downstream of station 4 while it was fairly good (4.55 ± 0.39) at station 5 due to the river self-purification. With changes and stresses of the river, increased and relatively decreased frequencies were observed in resistant and susceptible groups of the macroinvertebrates, respectively.

The continuity of antimicrobial resistance development in bacteria changes the type and dose of effective antibiotic treatments and makes routine monitoring studies necessary for successful control of bacterial diseases. This study was aimed to determine the current antibiotic susceptibility of Lactococcus garvieae, which causes significant economic losses in rainbow trout (Oncorhynchus mykiss) farms. In the study, two consecutive visits were made to three farms operating on the banks of a stream during a disease outbreak in the fall of 2018. At each visit, 10 fish showing the signs of disease from each farm (60 fish in total) were sampled and L. garvieae was isolated from 16 fish. All isolates were identified using conventional and molecular methods. Then, they were examined for 5 different antibiotic resistance genes and their antibiotic susceptibility profiles were determined using the Kirby Bauer disc diffusion technique. Results of the disc diffusion test revealed that all 16 isolates had a different antibiotic susceptibility profile and the isolates with different antibiotic susceptibility profile could exist within and between farms, using the same water source. Furthermore, they revealed that highly resistant isolates that showed no susceptibility up to 82 to 100% of the 33 antibiotics at the doses evaluated exist in all farms. All isolates carried either tetA or tetB genes or both and the majority of isolates carried tetA gene. Together with this, 25% of the isolates which carried both or one of the resistance genes showed susceptibility to all 4 tetracycline class antibiotics at the doses evaluated. Results of the study and their comparison with previous studies in the same production area or in different regions of the country revealed the dynamic nature of antibiotic resistance development in L. garvieae. Additionally, it showed that monitoring studies with a limited number of isolates may not give an accurate picture of the current status of antibiotic resistance from a production area. These results of the study were also discussed in terms of the treatment strategies that trout farmers should follow when treating lactococcosis.

Acanthocephalosis is caused by the endoparasite Neoechynorhyncus buttnerae and affects fish farmed in the Amazon. This study assessed the efficacy of therapeutic levamisole hydrochloride (LVC) baths against N. buttnerae and its effects on juvenile tambaqui blood parameters. In vitro and in vivo tests were carried out, the latter employing two experimental therapeutic LVC bath protocols. Concerning in vitro efficacy, the T75 (75 mg.L−1 LVC) and T100 (mg.L−1 LVC) treatments were 100% effective in 15 min, while the T50 (50 mg.L−1 LVC) and T25 (25 mg.L−1 LVC) treatments required parasite exposure for 45 and 60 min, respectively. During exposure, the parasites displayed reduced motility, proboscis retraction, coiling into a spiral shape, body rigidity and swelling. The LVC LC50–72h for juvenile tambaqui was 115 mg.L−1. Regarding in vivo efficacy for Protocol I (8‐h bath), the T125 resulted in 82% effectiveness, while in Protocol II (two 8‐h baths with a 24‐h interval), the T115 treatment (115 mg.L−1 LVC) achieved 95.6% effectiveness without clinical intoxication signs, despite behavioural changes. No significant changes were observed in fish blood parameters. LVC was, therefore, highly effective both in vitro and in vivo in controlling the acanthocephalan N. buttnerae without compromising tambaqui juvenile homeostasis. [ABSTRACT FROM AUTHOR]

A methodology for aquaculture site selection is presented using a combined hydrodynamic/nutritional model to predict fish farm wastes and dispersion, using the indirect fish waste estimation method, and the numerical model MIKE 21. This method can be used as a basis for assessment of the environmental impact of fish farms. The models were applied for a virtual inland fish farm to harvest 450 tons of sea bass in the west coast of Algeria. The results show that the fish farm effluents quantities and dispersion depends on the production cycle and size, the hydrodynamic parameters, as well as the food quantity and composition. The suspended waste, nitrogen and phosphorus are respectively the main contributors to the fish farm pollution. The current speed varies from 0.005 to 0.045 m/s, while the nitrogen and phosphorus concentrations reached 2.1 mg/L, and 0.03 mg/L respectively. This study allows the Algerian authorities to decide upon delivering fish farming permissions in the studied area, by identifying the suitability of the area for aquaculture, and predicting potential fish farm pollution. The use of numerical models in aquaculture could help reducing installation, water treatment costs and the environmental impact of fish farms by contributing to the sustainability of the activity. [ABSTRACT FROM AUTHOR]

“Enhancing the Wild” in itself is a contradiction. Our ocean is filled with ecosystems delicately balanced by a global interconnection that any outside intervention is bound to alter.Enhancement programs aim to target the impacts of natural and anthropogenic influences on wild fish stocks in hopes of increasing recreationally and commercially important species. However, many are lacking in adequate research and have the potential of throwing these ecosystems off-balance. Management by collaborating stakeholders taking a precautionary approach to minimize adverse effects on the environment and economy while also working with the best available science is how these programs will be most effective.The Hubbs-Seaworld Research Institute (HSWRI) Ocean Resources Enhancement and Hatchery Program (OREHP) located in Carlsbad, California is on the cutting edge of such initiatives. Though despite 30 years of valuable research and experience as well as 40 million dollars worth of funding to date, less than one percent of OREHP white sea bass has contributed to the wild population. Now, with stakeholders finally able to express their opinions across the same platform, a conversation about not only how we can effectively spawn, rear, and release white seabass into the wild, but if we can may take place

This study investigated fish production in Egypt. Under Fish Macroeconomics in Egypt, fish production has expanded to about 418,600 tonnes in 2020 from natural fisheries. But fish farming reached 1.59 million tonnes in 2020 (compared to 1.64 million tonnes in 2019, decreasing by 3%). Based on the fish microeconomics production function in fish farming, the independent variables can be arranged according to the relative importance of their impact on the fish mixture (mullet and tilapia). The variable feed quantity occupies the first place, followed by organic fertilisation, the number of fingerlings, the number of employees, the duration of the production cycle, the amount of oil and fuel, and finally the farm manager's experience. Based on the cost structure, fixed and variable expenses made up 13.2% and 86.8% of total operating costs, respectively. Based on the fish microeconomics profitability function, the findings revealed how successfully tilapia and mullet fish were produced per acre in sample farms in Fayoum Governorate: The ratio of total revenues to total expenses was roughly 1.9. The quantitative break-even threshold was 0.34, which means the production process is in the farm owners' interest. Therefore, fish farm profitability analysis is favourable. Encourage farm owners to maintain and grow production initiatives and handle producer difficulties.

For industrial water use planning, water usage and drainage per unit product standards must be established. This would allow for the conservation of fresh water resources without limiting irrigation in the face of the world’s ever-increasing drinking water deficit. Because fish farms use a lot of water, businesses that raise fish in artificial ponds usually dig deep wells to get to the valuable subsurface water they need. Because they lack a reusable water system equipped with treatment technologies, they typically discharge water into the environment after a single use, resulting in marshes, soil salinization, or transportation with surface water flow to the brackish water ecosystem. In recent years, the use of groundwater for fishing has spread in Armenia’s Ararat plain, one of the country’s most important agricultural regions. The Ararat plain has a water shortage for irrigation, which is mostly addressed by increasing water intake volumes from Lake Sean, a critical source of drinking water. In the absence of a multi-use hydrosystem with cleaning technologies, a method of utilizing fish farm wastewater for irrigation purposes is proposed as a water-saving and environmental-protection approach.

The continuity of antimicrobial resistance development in bacteria changes the type and dose of effective antibiotic treatments and makes routine monitoring studies necessary for successful control of bacterial diseases. This study was aimed to determine the current antibiotic susceptibility of Lactococcus garvieae, which causes significant economic losses in rainbow trout (Oncorhynchus mykiss) farms. In the study, two consecutive visits were made to three farms operating on the banks of a stream during a disease outbreak in the fall of 2018. At each visit, 10 fish showing the signs of disease from each farm (60 fish in total) were sampled and L. garvieae was isolated from 16 fish. All isolates were identified using conventional and molecular methods. Then, they were examined for 5 different antibiotic resistance genes and their antibiotic susceptibility profiles were determined using the Kirby Bauer disc diffusion technique. Results of the disc diffusion test revealed that all 16 isolates had a different antibiotic susceptibility profile and the isolates with different antibiotic susceptibility profile could exist within and between farms, using the same water source. Furthermore, they revealed that highly resistant isolates that showed no susceptibility up to 82 to 100% of the 33 antibiotics at the doses evaluated exist in all farms. All isolates carried either tetA or tetB genes or both and the majority of isolates carried tetA gene. Together with this, 25% of the isolates which carried both or one of the resistance genes showed susceptibility to all 4 tetracycline class antibiotics at the doses evaluated. Results of the study and their comparison with previous studies in the same production area or in different regions of the country revealed the dynamic nature of antibiotic resistance development in L. garvieae. Additionally, it showed that monitoring studies with a limited number of isolates may not give an accurate picture of the current status of antibiotic resistance from a production area. These results of the study were also discussed in terms of the treatment strategies that trout farmers should follow when treating lactococcosis. [ABSTRACT FROM AUTHOR]

The objective of the developed system is to encourage efficient water management practices that optimize the usage of water by keeping crop health and yield intact through the implementation of an automated irrigation system. The study aimed to determine the impact of irrigation by fish farming on growth rates and concentrations of macro- and micronutrients in tomatoes. Results indicated that irrigation with fish farm effluent significantly increased and effluent water, depending on its composition to feed the fish, can supply nutrients and increase the concentrations of these elements in tomatoes irrigated with this water with a refractive index = 1.3391 and a calorie value of 19.927 Calorie in the first sampling and 16.696 calories in the second sampling for 100 g for the year 2021 and for the year 2022 we have a refractive index = 1.3495 and a calorie value of 20.66 Calorie for 100 g. Here we show for the first time that is more than the standard norm (Cotte.2000) which is 18 Calories. Also, after carrying out microbiological analyzes, there is a total absence of pathogenic bacteria, as well as the organoleptic parameters are heading in the right direction where tomatoes irrigated by fish farming water is concentrated compared to the tomatoes irrigated by normal fresh water with Light red of 53 %, Cooked acid of 47 %, spherical form of 94 % and a pleasant smell of 88 %. Therefore, using fish farm effluent in irrigation provides water requirements for plants and also can improve the availability of nutrient elements for tomatoes.

The study determined the following heavy metals: cadmium (Cd), chromium (Cr), copper (Cu), manganese (Mn), lead (Pb) and zinc (Zn) concentrations in surface water and in fish pond (water, sediments and farmed fish (Clarias gariepinus)) from a fish farm cluster with the view of assessing its pollution level and associated human health exposure risk to these heavy metals through fish consumption. Samples were digested with aqua regia and metal concentrations were determined with an atomic absorption spectrophotometer equipped with an air acetylene flame. Mean concentrations of the heavy metals (ppm) in surface and pond water ranged as follows: cadmium (below detection limit (bdl): 0.298); chromium (bdl: 0.257); copper (bdl: 0.067); manganese (bdl: 0.163); lead (bdl: 0.736) and zinc (bdl: 0.078) while in sediment, the ranges (mg/kg dry weight) were as follows: cadmium (1.156–3.329); chromium (9.439–14.373); copper (26.710–121.819); manganese (3.143–37.202); lead (0.340–1.537) and zinc (87.681–371.060). The mean concentrations of the metals in surface water were significantly different (p < 0.05) from those in sediment in all the sampling sites. The mean metal concentrations (mg/kg dry weight) in C. gariepnus were in the following ranges: cadmium (0.733–1.405); chromium (0.593–1.692); copper (175.882–245.321); manganese (bdl: 3.326); lead (0.221–0.263) and zinc (248.191–292.333). Some of the heavy metal concentrations obtained in water, sediment and catfish analyzed were above the permissible limit set by some National (DPR) and International organisations (WHO, FEPA and FAO). The pollution studies showed that lead, cadmium and chromium contaminated the surface water samples. Sediment from all sites showed low to considerable contamination by the heavy metals. The human exposure risk assessment of the metals showed that the total hazard index was less than one which indicates no probable adverse health effect from the consumption of fish from the ponds, although this case is different for Pb since there is no estimation of oral reference dose (RfDo) for lead according to EPA. HIGHLIGHTS The levels of heavy metals in the fish and water were established.; Health risk associated with the consumption of the fish in the region was also established.; Sediment is the major uptake route and ultimate sink of heavy metal pollution and played a crucial role in heavy metal uptake by fish.; Consumption of farmed catfish from the ponds is safe for a normal consumer.;

In the Mediterranean, anthropogenic pressures (specifically those involving nutrient loads) have been progressively moved to deeper off-shore areas to meet current policies dealing with the protection of marine biodiversity (e.g., European Directives). However, conservation efforts devoted to protecting Posidonia oceanica and other vulnerable marine habitats against anthropogenic pressures have dedicated very little attention to the deepest areas of these habitats. We studied the remote influence of off-shore nutrient discharge on the physiology and structure of deep P. oceanica meadows located nearest to an urban sewage outfall (WW; 1 km) and an aquaculture facility (FF; 2.5 km). Light reduction and elevated external nutrient availability (as indicated by high δ15N, total N and P content and N uptake rates of seagrass tissues) were consistent with physiological responses to light and nutrient stress. This was particularly evident in the sites located up to 2.5 km from the WW source, where carbon budget imbalances and structural alterations were more evident. These results provide evidence that anthropogenic nutrient inputs can surpass critical thresholds for the species, even in off-shore waters at distances within the km scale. Therefore, the critical distances between this priority habitat and nutrient discharge points have been underestimated and should be corrected to achieve a good conservation status. [ABSTRACT FROM AUTHOR]

The expected bioremediation effect, driven by the conversion of an inshore mariculture plant into an Integrated Multi-Trophic Aquaculture (IMTA) system, which could mitigate the fish farm impact, related to the accumulation of organic matter on the seabed, has been studied. The ecological quality status was studied following a Before-After-Control-Impact (BACI) design and variation measured through M-AMBI and compared with the results of univariate and multivariate analyses of variance, to evaluate the sensitivity of the two methodologies. Results from M-AMBI indicated a sharp change in the ecological quality status, just after one year of the conversion of the plant. By contrast, although changes were detected also utilizing univariate and multivariate statistical analysis, the natural temporal variability characterizing the area partially masked evidence of environmental amelioration. [ABSTRACT FROM AUTHOR]

Effectiveness of the salmon juveniles feeding was examined during six cycles of fish breeding for pink salmon Oncorhynhus gorbuscha, chum salmon O. keta, cherry salmon O. masou, and coho salmon O. kisutsh at 12 fish hatcheries belonged to the Sakhalin branch of FBSI Glavrybvod with using of different starter feeds produced by Aller Aqua (Denmark) and Aquatech (Russia). All hatcheries worked in the coldwater regime of rearing. Both feeds were rather effective for all species that was evidenced by low feeding coefficients, usually 0.6–0.8. Anyway, average value of the feeding coefficient was lower for the starter feed Aquatech at all factories. Beyond a high quality of this feed, its availability in two variants of flotation was important, as the slowly sinking and floating forms. The floating food was found to be more suitable for the growing juvenile pink salmon at all farms. On the other hand, both starter feeds were suitable for chum salmon, their priority for this species depended on fish farm and obviously was determined by combination of many factors, such as temperature conditions, configuration of canals and ponds, their hydrodynamics, feed dispensers, etc.

The increasing trend of antimicrobial resistance (AMR) pathogens in aquaculture makes it is imperative to find control measures for AMR pathogens causing high economic losses in aquaculture. In the present study, a multidrug resistance (MDR) Aeromonas hydrophila bacterium was isolated from kidney samples of diseased carp originating from a fish farm in Awankot, Rupnagar, Punjab, India. Moribund-infected fish exhibited large irregular hemorrhages on the external body surfaces, exophthalmia and fin-rot-like lesions. Phenotypic characterization using Rimler-Shotts (RS) media showed characteristic yellow color colonies and beta hemolysis on sheep blood agar. Genotyping using species-specific primers for the rpoB and gyrB genes characterized the isolate as A. hydrophila. The Multiple Antibiotic Resistance (MAR) index analysis showed that the isolated A. hydrophila had an MAR score of 0.29 signifying its resistance to more than three antibiotics, which underscores the need of finding treatment methods for MDR A. hydrophila isolates causing disease in aquaculture. Bacteriophages are considered a better eco-friendly alternative to antibiotics because of their inherent properties of not causing drug residues and resistance. Of the 13 phages tested, the Aeromonas veronii phage designated as AVP3, initially isolated against Aeromonas veronii , showed lytic activity against the MDR A. hydrophila isolated from diseased carp in this study. In addition, it also showed the lytic activity against Aeromonas spp. And A. caviae indicating that it had lytic properties against a wide host range within the Aeromonas species. This finding points to the potential efficacy of bacteriophages in mitigating pathogenic infections in aquaculture. • Three-tier method identified causative agent (A. hydrophila) for disease outbreak. • MAR index of multi drug resistant (MDR) A. hydrophila pathogen was 0.29 • Phage- AVP3 effective against the A. hydrophila (MDR), A. veronii and A. caviae. [ABSTRACT FROM AUTHOR]

Worldwide, aquaculture is the fastest growing agri-industry. Globally, opportunities exist to introduce or explore alternative species, new strains or highly selected stocks that represent substantial appeal to aquaculture. Movement of these products and organisms presents challenges to resolve potential interactions with the native ecology, the transfer of diseases to either freshwater fish culture or wild stocks and the potential transfer of contaminants or pathogens of concern for human food safety. The actual biosecurity culture at the majority Romanian fish farm facilities is one of indifference, denial and avoidance; a true “it won’t happen to me” mentality. The formation and changes of attitudes and behaviors within the environment at a place of business has to be done top-down, from managers to laborers. There are numerous potential sources of entry for an infectious agent into an aquaculture facility. These include additions of new stocks as: embryoned eggs, larvae, fry, juvenile and broodstock. Contaminated water or feed, humans, animals or equipment, and sub clinical (asymptomatic) carriers within the existing stock (production fish or broodstock) might be other sources. General biosecurity measures need to be established for each facility to help support the activities of both disease prevention and disease control. A manual of standard operating procedures should be assembled to provide a set of standard rules for biosecurity measures and disease monitoring. The implementation of a specific biosecurity protocol might change the culture to better suit the aquaculture business and its goals.

Analysis of turnover involves the causal relationships between different factors (quantity, quality and structure) and changes in economic and financial phenomenon. Such a study is required arguments for a set of management measures geared towards improving work farms analyzed. The evolution over time in turnover was based on known statistical models. The period considered in the study farm is 2007-2008, and turnover analysis refers to the business of delivering fresh and frozen fish. Following the study found that modification of fish production during the two years the level of the average price of delivery and, ultimately, turnover of the holding. Thus in 2007, fresh fish represented 56% of the total quantity of fish delivered, in 2008 the share of fresh fish delivered was only 45.5% of the total production of fish delivered. This change in structure has helped to increase overall turnover resulting from the fish market in the year 2008 consisted of turnover from the sales of fresh fish 43.7%, 56.3% difference is that of fish delivered frozen.

Aquaculture is becoming a strategic sector for many national economies to supply the increasing demand for fish from consumers. Fish culture conditions and processing operations can lead to an increase in microbial contamination of farmed fish that may shorten the shelf-life of fish products and byproducts, and ready-to-eat fishery products. The objective of this study was to evaluate the hygienic-sanitary status of water, environment, and processing of fresh-farmed rainbow trout (Oncorhynchus mykiss) fillets produced in a local fish farm in Andalusia, Spain. To achieve this, a longitudinal study was carried out by collecting environmental (air and food-contact surfaces), water from fish ponds, and rainbow trout samples. Thereby, seven sampling visits were performed between February 2021 and July 2022, where foodborne pathogens and spoilage microorganisms, together with physicochemical parameters, were analysed in the collected samples. Further, microbial identification of microbiota was achieved through a culture-dependent technique using blast analysis of 16S RNA gene sequencing. The results showed that Listeria monocytogenes and Salmonella were not detected in the analysed samples. Regarding the hygienic-sanitary status of the fish farm, the slaughtering bath, the eviscerating machine and the outlet water from fish ponds presented the highest counts of coliforms, Enterobacteriaceae, and Aerobic Mesophilic Bacteria. Staphylococcus aureus and sulphite-reducing Clostridium were identified in the conveyor belts, fish flesh, and viscera. The 16S RNA identification confirmed the presence of viable spoilage bacteria such as Citrobacter gillenii, Macrococcus caseolyticus, Hafnia paralvei, Lactococcus lactis, Lactococcus cremoris, Klebsiella, Escherichia coli, Morganella morganii, and Shewanella. Three of these genera (Citrobacter, Hafnia, and Pseudomonas) were present in all types of samples analysed. The results evidenced potential transmission of microbial contamination from contaminated packaging belts and boxes, evisceration and filleting machines to flesh and viscera samples, thus the establishment of control measures should be implemented in fish farm facilities to extend the shelf-life of farmed fishery products.

Austropotamobius torrentium (Schrank, 1803) lives in two watercourses, namely Subotica (Sana) and Toplik (Tilava). The influence of the ecological conditions of these rivers on individuals of this species is analyzed based on 22 morphometric parameters. The assessment of abiotic conditions was done through the measurement of physical and chemical water parameters and the analysis of the composition of phytobenthos and macrozoobenthos. Sampling was carried out in June, September, and October 2021. Water quality at the investigated localities (on the basis of abiotic and biotic parameters) is oligo to betamesosaprobic. A total of 37 crayfish were analyzed (20 from Subotica and 17 from Toplik). Female crayfish have shown significant differences in the head width (HEW) and abdominal thickness (ABH). Males differed significantly in a number of parameters, including the weight (W), head shape (HEL and HEW), rostrum length (ROL), carapace width (CPW), and abdominal shape (ABH and ABL). Higher values of the indicated parameters have been found in the males from the Subotica River. The obtained results are influenced by different ecological conditions of their habitats. The Subotica River is a larger watercourse in the lowland belt with a large number of microhabitats, and the Toplik is a small river in the mountain belt, with uniform sediment and a small number of ecological niches of the analyzed species. The general ecological conditions in the water of both watercourses are also affected by aquaculture facilities, where wastewater has a direct influence on the distribution of Austropotamobius torrentium individuals in the watercourses of the Subotica and Toplik Rivers. For more detailed and complete data, it is necessary to analyze a larger number of individuals in both populations, and to include additional morphometric-meristic parameters and molecular-genetic analyses.

Serbian aquaculture is practiced in warmwater (carp) farms, coldwater (trout) farms, cage systems, recirculating aquaculture systems (RAS) and fish tanks. The total area under carp farms (ponds) registered by the Statistical Office of the Republic of Serbia (SORS) in the last fourteen years has varied between 6,192 and 8,940 ha, while under the area under trout farms was between 33,255 m2 and 81,411 m2. Total fish production over the last fourteen years varied between 5,070 tons, recorded in 2017 and 8,195 tons of market fish, recorded in 2010. Fish production is dominated by common carp and rainbow trout (about 90% of total production). In addition to these two species, several other species are cultured at carp farms, such as catfish, pikeperch, pike, silver carp, bighead carp, grass carp, Prussian carp and tench. In trout farms, additional cultured species are usually brook trout, huchen and grayling, while cultured fish species in RAS systems are sterlet and Russian sturgeon.

Vibrio species are widely distributed and can be potentially pathogenic to aquatic organisms. In this study, we isolated Vibrio spp. from environmental samples (seawater, sediment, and fish swabs) collected over a three-year period from a fish farm in Mali Ston Bay in the Adriatic Sea, Croatia, and assess their distribution. A total of 48 seawater samples and 12 sediment samples, as well as gill and skin swabs from 110 farmed European seabass, were analysed for the presence of Vibrio. Vibrio strains were identified to the species level by MALDI TOF MS. The analysis revealed that V. alginolyticus was the predominant species in European seabass, followed by V. anguillarum. V. alginolyticus was isolated from the sediments, along with V. gigantis and V. pomeroyi, while V. chagasii, V. cyclitrophicus, V. fortis, V. gigantis, V. harveyi, V. pelagius, and V. pomeroyi were isolated from seawater. V. anguillarum was isolated only twice during two different spring seasons, once from a diseased sea bass and the second time from a healthy sea bass. We analysed these two isolates and found that they differ both genetically and in terms of resistance to antibiotics. Our results confirm the seasonality of vibriosis incidence and the presence of the pathogenic V. anguillarum, which increases the risk of vibriosis. [ABSTRACT FROM AUTHOR]

World aquaculture is increasingly diversified and intensive, due to the use of new technologies, having grown a lot in recent decades and contributed significantly to improving food security and reducing poverty in the world, with fish farming being a promising activity for the production of protein with high nutritional value. The large aquaculture companies that recognize the potential of this important modality have invested in the study and production of various productive segments of the most diverse species of fish. This review article aims to provide information on the world panorama of marine fish farming, with the main systems and production stages of the most important organisms with commercial potential, aiming to achieve a highly sustainable production, with high nutritional content and benefits for human health. The production of live feed in the larval stage should be highlighted, in order to optimize survival and weight gain. In addition, trends in the cultivation of estuarine and saltwater fish will be detailed in this review, such as the use of biotechnology and technological innovations, cultivations integration, and biosecurity. Thus, innovative methods to optimize the farming system need to be more ecosustainable, reducing the negative impacts on the environmental level. [ABSTRACT FROM AUTHOR]

There are increasing concerns over the possible effects of aquaculture pens on the local abundance and residency of sharks, and its associated risk for shark bites at nearby beaches and surf breaks. We used acoustic tracking and a before–during–after–control–impact design to assess the residency and local abundance of 117 bronze whalers and 843 white sharks around a 45-m-diameter aquaculture pen installed in South Australia for tourism purposes. Only 14 bronze whalers (12.0% of individuals tagged) and nine white sharks (1.1% of individuals tagged) were detected throughout the 5-year monitoring period and there was no evidence of the pen affecting these sharks, in either the number of sharks detected or number of detections (proxy for length of time detected). The low amount of interactions with the pen was likely to be due to a combination of low fish biomass, pen installed in a shallow location, local shark species being migratory species, and good husbandry practices. Adequate planning and management, and good husbandry practices, such as removal of dead fish from pens and avoiding over-feeding to ensure the feed is entirely consumed, are key to reducing shark interactions with cage fish and associated infrastructure. Sharks are often observed interacting with caged fish and aquaculture industries. We tracked ∼900 bronze whalers and white sharks to determine whether local shark populations are affected by an aquaculture pen installed for tourism purposes. We found no evidence that sharks were attracted by the pen or stayed in the region for extended periods because of the pen. Good husbandry practices, shallow location, and shark species being migratory likely contributed to the low number of interactions with the pen. [ABSTRACT FROM AUTHOR]

The objective of this study is to assess the physico-chemical quality and the trophic state of the waters of a fish farm in ponds located in Abengourou in the east of the Côte d'Ivoire. The physicochemical parameters were determined in water samples collected on the farm from September to October 2020 according to the NF T90-105 standard of AFNOR (1997). The monthly values of temperature, hydrogen potential, dissolved oxygen, conductivity, total dissolved solids, transparency and suspended matter are respectively between 28.28 - 30.87 °C; 6.2 - 8.18; 5.28 - 6.92 mg/L; 32 - 101 µS/cm; 21 - 42 mg/L; 25 - 43.6 cm and 101.69 - 149.58 mg/L. Monthly concentrations of nitrite, nitrate, ammonium, phosphate and chlorophyll-a in farm water respectively ranged from 0.009 to 0.028 mg/; from 3.7 to 16.6 mg/L; 1.04 to 2.69 mg/L, 2.2 to 4.3 mg/L and 2.6 to 6.6 µg/L. The values of the measured parameters were compared with the standards recommended for the breeding of tilapia Oreochromis niloticus. The comparative analysis revealed that most of the water quality parameters are suitable for the breeding of the fish Oreochromis niloticus. However, the transparency, the conductivity and the recorded phosphate results were not compliant with the standard values, which are respectively between 30 - 80 cm, 150-450 µS/cm and 0.5 mg/L. The values of the TDS / EC ratios (0.48 - 0.78) and the pollution indices (2.00 - 2.66) showed a strong mineralization of the water and a high level of organic pollution in all the structures of the farm which indicate a eutrophic state of the water of the dam and the ponds. So this eutrophication phenomenon can lead to long-term stress and mortality of fish if adequate measures are not taken. [ABSTRACT FROM AUTHOR]

State of blood cells is examined for juveniles of pink and chum salmon sampled from Lesnoy Pugachevsky, Taranaisky and Okhotsky hatcheries in Sakhalin in May-June of 2018 and 2019 and caught in the Ochepukha, Pugachevka and Taranay Rivers during their catadromous migration to the sea. Both hatchery and wild juveniles of both species were characterized by high adaptive capabilities evidenced with high content of young forms of erythrocytes in the blood (17.0–31.0 %), significant portion of lymphocytes (60.8–92.0 %), and small number of neutrophils. The high adaptive capabilities were confirmed in the experiment, when juveniles of pink salmon were placed in the seawater without preliminary acclimation, but noticeable changes in the state of blood cells were not revealed both for wild and hatchery-reared specimens. Proportion of different blood cells was highly variable for juveniles of both artificial and natural origin but was more similar between the fry hatched at the same hatcheries or in the same rivers. A case of increased number of neutrophils was noted in 2019 for certain groups of juveniles, with total increasing of platelets in the blood that was explained by an external influence on the juveniles.

Abstract Monogenean infestations can cause high mortality in farmed fish and therefore significant economic losses. The present study investigated the efficacy of albendazole in therapeutic baths against monogeneans of Piaractus brachypomus Cuvier, 1818 and Megaleporinus macrocephalus (Garavello & Britski, 1988). For both fish, a 24 hours therapeutic bath with albendazole concentrations of 150, 300 and 500 mg/L were tested against monogeneans from the gills. The baths had an efficacy from 61.4 ± 32.9 (95%CI=64.5) against monogeneans of P. brachypomus, and from 95.4 ± 5.6 (95%CI=10.9) against monogeneans of M. macrocephalus. In P. brachypomus, the hepatosomatic index (HSI) in fish exposed to 150 mg/L of albendazole was higher than in fish exposed to 300 mg/L. The splenosomatic index (SSI) values in fish exposed to 150 mg/L of albendazole were lower than in fish exposed to 300 mg/L. In M. macrocephalus, the HSI and SSI values decreased in treatments with 150, 300 and 500 mg/L of albendazole to control and treat infestations by monogeneans. For M. macrocephalus, 150 mg/L of albendazole can be used to control and treat infestations by monogeneans, while for P. brachypomus 500 mg/L of albendazole can be used in a 24 hours bath.

The study determined the following heavy metals: cadmium (Cd), chromium (Cr), copper (Cu), manganese (Mn), lead (Pb) and zinc (Zn) concentrations in surface water and in fish pond (water, sediments and farmed fish (Clarias gariepinus)) from a fish farm cluster with the view of assessing its pollution level and associated human health exposure risk to these heavy metals through fish consumption. Samples were digested with aqua regia and metal concentrations were determined with an atomic absorption spectrophotometer equipped with an air acetylene flame. Mean concentrations of the heavy metals (ppm) in surface and pond water ranged as follows: cadmium (below detection limit (bdl): 0.298); chromium (bdl: 0.257); copper (bdl: 0.067); manganese (bdl: 0.163); lead (bdl: 0.736) and zinc (bdl: 0.078) while in sediment, the ranges (mg/kg dry weight) were as follows: cadmium (1.156-3.329); chromium (9.439-14.373); copper (26.710-121.819); manganese (3.143-37.202); lead (0.340-1.537) and zinc (87.681-371.060). The mean concentrations of the metals in surface water were significantly different (p, 0.05) from those in sediment in all the sampling sites. The mean metal concentrations (mg/kg dry weight) in C. gariepnus were in the following ranges: cadmium (0.733-1.405); chromium (0.593-1.692); copper (175.882-245.321); manganese (bdl: 3.326); lead (0.221-0.263) and zinc (248.191-292.333). Some of the heavy metal concentrations obtained in water, sediment and catfish analyzed were above the permissible limit set by some National (DPR) and International organisations (WHO, FEPA and FAO). The pollution studies showed that lead, cadmium and chromium contaminated the surface water samples. Sediment from all sites showed low to considerable contamination by the heavy metals. The human exposure risk assessment of the metals showed that the total hazard index was less than one which indicates no probable adverse health effect from the consumption of fish from the ponds, although this case is different for Pb since there is no estimation of oral reference dose (RfDo) for lead according to EPA. [ABSTRACT FROM AUTHOR]

The rapid development and intensive production of aquaculture have brought to light various environmental problems. In particular, fish farming adversely affects the benthic environments through the accumulation of organic matter (OM), which leads to the degradation of aquatic sediments and associated biotic communities. To prevent environmental degradation, proper site selection for fish farming is a prerequisite for sustainable aquaculture practices. An important physical factor in selecting a site for fish farming is sediment structure. Coarser sediments are preferred, while their mineral composition is rarely discussed. To investigate relationships between sediment characteristics and the content of OM, sediments were collected from three different sites with different aquaculture practices under different climatic and environmental conditions and analyzed during the one-year monitoring period. Grain size distribution, mineral composition, carbonate content, and organic matter content were determined for three fish farm sites (Ilova, River, Krka River, and Pelješac) and their reference sites. Preliminary results from all studied sites showed that sediment texture in combination with natural mineral composition is one of the key factors for the accumulation of OM in the sediment. In particular, the mineral composition of the fine-grained sediment should be known when conducting an environmental impact assessment of fish farms. [ABSTRACT FROM AUTHOR]

The global population is increasing and technical efforts have to be put in place to assure food security especially for the much needed animal protein for the growing human population. Several efforts are focused on fish production to cope with the demand. Research has been done in aquatic ecosystems by installing fish production infrastructures as well as floating cages. This review aims to examine the information available on floating cages in terms of density, feeding mode, economic profitability, socio-economic impact and load capacity determination model. Some keywords related to the topic were considered when using the scientific databases such as Google Scholar, Web of Science, Scopus and in the Researchgate database as well as Agora. A total of 65 important scientific manuscripts as material were used. From the review, it appears that the loading density in a floating cage depends on the species, the loading weight and on the water body. Feeding is based on food intake, while the optimization of natural food would significantly reduce the cost of production. Caged aquaculture contributes to food security and reduces youth unemployment. Economic profitability is a function of production factors, water quality and is strongly influenced by feed costs. It should be noted that any ecosystems awaiting exploitation for cage aquaculture must be subjected to carrying capacity determination and the best model for this determination is Dillon and Rigler (Dillon & Rigler, 1974). Therefore, studies on each species in a given ecosystem and research on the rate of ration and the appropriate frequency of feeding (due to the contribution of the natural food) are necessary to optimize fish yield at the level of each country.

Mooring lines and aquaculture nets are important components in fish farm systems. During the design stage of the fish farm systems, a numerical method of high computational performance to calculate the structural responses of the mooring lines and aquaculture nets is required. The present study aims to explore the applications of an extended position-based dynamics (XPBD) algorithm to the structural modelling of the mooring lines and aquaculture nets and verify the XPBD by comparing the performances with the mass-spring model and FEM of Code_Aster. Three typical cases about the mooring lines and aquaculture nets, including the twelve mooring lines of a floating dock, the flexible net with three sinkers and the lifting operation of a fish cage are discussed. In these cases, the sensitivity studies on the time-step, number of elements and damping ratio are performed to determine the proper settings of these approaches. The accuracy of the original XPBD is improved by adding correction forces to the nodes associated to the spring constraints. Among all the cases, the present modified XPBD can yield results including the static positions, tensions, lifting forces and dynamic deformations of the mooring lines or aquaculture nets that are comparable in accuracy with the mass-spring method and FEM of Code_Aster. The modified XPBD and mass-spring model require much less computational resources than the FEM of Code_Aster for the cases of the twelve mooring lines of a floating dock and the lifting operation of a fish cage. The present modified XPBD can be effectively applied to lifting operations of fish cages involving current loads. Therefore, the proposed modified XPBD can be a new alternative for the structural modelling of the mooring lines and aquaculture nets. • The present study will explore a new efficient method named extended position-based dynamics (XPBD) method in simulations of the structural responses of the mooring lines and aquaculture nets. • The original XPBD is not accurate and needs to be corrected. It can be improved by using small time step, but the computational cost thereby increases. The modified XPBD is proposed by adding correction forces to the nodes associated to the constraints. • The performances of three approaches, including mass-spring method, extended position-based dynamics method and finite element method, are evaluated in this study. [ABSTRACT FROM AUTHOR]

This study aimed to identify anatomopathological injuries in sick, moribund, or recently dead fish from an experimental fish farm in the Peruvian Amazonia with a necropsy, direct microscopic, and histopathological examination. The study was carried out at the migratory fish production unit where cachama (Colossoma macropomum), pacus (Piaractus brachypomus), black prochilodus (Prochilodus nigricans), and spotted tiger shovelnose catfish (Pseudoplatystoma punctifer) are bred. Furthermore, from the non-migratory fish unit where arapaima (Arapaima gigas) and Nile tilapia (Oreochromis niloticus) are bred at the fish farm within the Experimental Station of the IVITA Research Center in Ucayali, Peru. Thirty clinical cases distributed in thirteen incidents of diseases observed between January 2013 and June 2014 were evaluated. The tissue macroscopic and microscopic evaluations were performed through necropsies to determine the injuries and the possible causes of mortality. Samples of the skin and gills mucous membrane were collected to identify parasites by direct microscopy, and liver, kidney, and spleen imprints stained with Gram were made to observe the presence of bacteria. Histopathological analyzes of the affected tissues were also performed in some of the evaluated cases. Parasites, mainly trematodes, were found in cachama, protozoa in arapaima, and bacteria suggestive of Flavobacterium sp. in spotted tiger shovelnose catfish. Digestive (14/30), respiratory (9/30), and traumatic (3/30) injuries were identified. [ABSTRACT FROM AUTHOR]

Hyphessobrycon eques has a great prominence in fishkeeping and scientific research. In this context, a systematic literature review was performed to assist in the improvement of captive breeding of this species and to identify knowledge gaps. Notably, of the 966 articles published between 1997 and 2020 found in an initial screening of the digital libraries of Google Scholar, PubMed, SciELO, Science Direct, and Scopus, only 56 represented research on the species according to the established criteria. Considering aspects pertinent to captive reproduction, 25 studies were selected. These studies addressed information regarding reproduction; embryonic, larval, and juvenile development of the species; parasitic fauna; limiting concentrations of prophylactic agents; food preferences; and dietary supplements already used for these fish. Only seven studies reported information on the physicochemical characteristics of water in natural habitats, with great variations in several parameters, mainly those related to temperature. In 5 of the 25 selected studies, information related to reproductive characteristics and/or embryonic, larval, and juvenile development was addressed. However, only two studies developed experimental studies with information relevant to the captive breeding of the species. Studies to identify parasitic fauna and to analyze the use of prophylactic agents were also found. As for the information gaps on the cultivation of the species, there are no studies related to nutrition seeking to determine the species nutritional needs, including feeding frequencies, feeding durations, and specific amounts of food. Therefore, this review offers a great support for the breeding of H. eques by highlighting opportunities for new scientific studies that could enrich and collaborate in the breeding of this ornamental fish.

In the aquaculture industry, an efficient and safe water purification system is important to prevent mass mortality by virulent pathogens. As extensive use of traditional methods (e.g.: povidone-iodine, ozone, ultraviolet irradiation, formalin, and chlorine dioxide) have adverse effects on cultured fish, an appropriate and alternative water purification method is vital for the sustainability of the industry. Non-thermal plasma technology has been successfully used for various biomedical purposes (e.g: food sterilization, medical device disinfection, wound healing, cancer therapy, etc.) and has great potential to be used as a sterilizing system. However, few studies have been conducted on its usefulness in the aquaculture industry. In this study, we investigated the bactericidal efficacy of plasma-activated water induced by non-thermal plasma and its histopathological as well as immunological adverse effects on koi. A highly virulent Aeromonas hydrophila SNU HS7, which caused massive mortality of koi, was used for this study. Non-thermal plasma was applied for 10 min to the fish tanks with 1.2 × 109 CFU/mL SNU HS7 using PLMB-20 system to confirm the sterilization efficacy and to observe the survival and immunological reaction of koi for 14 days. As a result, gross pathological, histopathological, and immunological investigations did not reveal any significant adverse effects in fish as compared to the control groups. To the best of our knowledge, this is the first study showing that non-thermal plasma can be used for sterilization of rearing water without giving significant physiological damage to the fish, even under the assumption of extreme situations. As plasma can effectively sterilize not only bacteria but also other unknown pathogens, the results of this study are showing a promising future in purifying water in aquaculture practice. • Highly virulent A. hydrophila SNU HS7, toxic to koi, was isolated and identified. • Non-thermal plasma treatment shows excellent bactericidal efficacy. • First study to show–sterilization is possible without significant physiological damage to fish. • Applying plasma to aquaculture can prevent diseases caused by unknown pathogens. [ABSTRACT FROM AUTHOR]

A data acquisition and monitoring system was developed for an automated system of a smart fish farm. The fish farm is located in Jang Hang, South Korea, and was designed as circulation filtration system. Information of every aquaculture pool was automatically measured by pH sensors, dissolved oxygen sensors, and water temperature sensors and the data were stored in the database in a remoted server. Modbus protocol was used for gathering the data which were further used to optimize the pool water quality to predict the rate of growth and death of fish, and to deliver food automatically as planned by the fish farmer. By using JSON protocol, the collected data was delivered to the user's PC and mobile phone for analysis and easy monitoring. The developed monitoring system allowed the fish farmers to improve fish productivity and maximize profits. [ABSTRACT FROM AUTHOR]

Abstract This study aimed to assess the impact of effluent discharge from a medium-scale aquaculture fish farm on the water quality of a nearby receiving stream, Odo-Owa stream, near Ijebu-Ode (06° 49′ N, 003° 56′ E) in Ogun State, Southwest Nigeria. Some physicochemical water quality parameters of the effluent receiving stream were determined at seven selected sites, above and below the effluent discharge point into the stream to assess the effluent impact on the water body. The seven sampling stations comprised three stations (A–C) located upstream of the effluent discharge point (Station D), two stations (E and F) located downstream of Station D, while the seventh station (Station G) was a close-by reference groundwater source. The water quality parameters investigated include five physical parameters (water temperature, apparent color, true color, turbidity and transparency), seven general chemical parameters (pH, conductivity, TDS, total alkalinity, total hardness, ammonia and DO), seven major ions (Ca2+, Mg2+, Na+, K+, Cl−, SO4 2− and HCO3ˉ), three nutrient compounds (PO4 3−, NO3 − and NO2 −) and five heavy metals (Hg2+, Mn2+, Fe2+, Cu2+ and Zn2+). Water samples were collected from each sampling station twice per season: dry season (December 2013 and February 2014) and rainy season (April and July 2014), and analyzed in the laboratory using standard analytical methods. The result showed a significant difference (P