Fish Ponds Research Articles

Growth Inhibition of Algae in Aquaculture Fishponds Using Banana Peel Powder: A Mesocosm Experiment

Cyanobacterial blooms and algal problems in aquaculture fish-ponds have become a significant concern for fish farmers due to the resultant decline in fish production. While numerous studies have been conducted globally on cyanobacterial blooms in oceans and lakes, relatively few have focused on the inhibition of algal biomass affecting aquaculture fish ponds. This study evaluated the potential of banana peel ashes and potassium sulphate to inhibit algal growth in fish ponds through a six-week mesocosm experiment using varying ash concentrations (i.e., 2, 4, 6, 8, 10 g·L−1). Differences among treatments in nutrient variables (nitrates, ammonium, and phosphates) were analyzed at the conclusion of the experiment. Factorial repeated measures ANOVA was employed to assess significant experimental differences in physicochemical variables across the study weeks (i.e., 1–6 weeks), treatments (three levels, including controls), and ash concentrations. Additionally, algal growth inhibition was assessed by measuring chlorophyll-a concentration over the six-week period. Banana peel ashes exhibited significantly greater efficacy in inhibiting algal growth compared to potassium sulphate, with the exception of the controls. However, no clear patterns were observed on nutrient dynamics throughout the experiment. The study demonstrated that banana peel ashes were more effective in inhibiting algal biomass compared to potassium sulphate, while physicochemical variables remained largely unchanged from the start to the end of the experiment. Given the efficacy of banana peel ashes as an inhibitor in this study, further research is recommended to investigate their potential impacts on fish within the ponds.

Pesticide Residues in Cabbage and Nile Tilapia and Implications on Human Health and Ecosystems: A Case of Fogera District in Ethiopia.

Pesticides have posed health risks to consumers and the ecosystems in different parts of the world, including Ethiopia, and researchers recommend continual assessments of pesticide residues in food items and ecosystems to know the level of risks. This study aimed to quantify the pesticide residues in samples of cabbage and fish and their risks to humans and the ecosystems. The cabbage samples were collected from April to May 2023 from 3 market centers, and the fish samples were collected in June 2023 from two fish ponds of Fogera District of Ethiopia using appropriate sampling procedures, extracted using the modified QuEChERS methods, and analyzed using a triple quadrupole GC/MS technique to quantify the pesticide residues and level the risks to humans and the ecosystems. The findings of the present study confirmed that all the samples of cabbage and fish were contaminated with pesticide residues. More than 44% and 37% of pesticide residues detected in both cabbage and fish samples were organochlorine and organophosphate pesticides, respectively. Furthermore, 92.86% of the pesticide residues and 96.43% of the maximum pesticide residues in cabbage exceeded the MRL and the TQ set by the Codex Alimentarius Commission. The sum total hazard indices of the pesticide residues in the cabbage (22.320) and fish (43.071) were much higher than the threshold value. Though Fogera District is a potential area for fish production in ponds, agricultural pesticides are a threat to the sector. Establishing an efficient system of monitoring for the pesticide supply chain and application procedures, choosing the appropriate pesticide types, timing in spraying, and establishing pesticide-free buffer zones are crucial steps in mitigating the negative effects of pesticides in the area.

The protein transition—environmental footprints of farmed fish, microalgae and chicken for food, a case study in Kenya

AbstractChallenges of land scarcity, climate change and water shortage are contributing to escalating the shortage of protein rich food in sub-Saharan Africa. In Kenya a total of 27.8% of the population was undernourished, and a total of 72.3% were categorised as moderately or severe food insecure in 2021–2022. The need to investigate alternative protein sources with less impacts on land, water and climate change, which potentially could replace, at least some of the current production of livestock as the main protein source, is getting increasingly urgent. The main aim of this study is therefore to conduct an environmental footprint analysis of favourable protein production systems in Kenya to evaluate environmental impacts on land, water, and climate. The methodological approach used in this study is referred to as environmental footprint analysis, which is applied to assess; (1) farmed fish in ponds, (2) farmed fish in solar based affordable recirculation aquaculture systems (A-RAS), (3) dried spirulina (Arthrospira Platensis), and (4) chicken from semi-intensive farms. The results show that the most promising alternatives to cattle production are dried spirulina produced in ponds, followed by fish produced in affordable recirculation systems (A-RAS) run on solar energy. Spirulina fully replacing beef production would reduce water usage with 34.7 billion m3/year, land/water surface area with 34.8 thousand km2/year, and GHG emission with 28.2 megaton CO2eq/year. For fish farmed in A-RAS, such replacement would reduce water, land and emissions with 30.7 billion m3/year, 32.0 thousand km2/ year and 23.0 megaton CO2eq/year, respectively. This study illustrates that it is possible to tackle urgent challenges of food and nutrition security for millions of people in sub-Saharan Africa and worldwide with a sustainable protein transition towards a more sustainable, inclusive production system of small-scale farmers, if making use of alternative protein sources, such as from solar based A-RAS and microalgae.

Automation System of Water Circulation and Fish Feeding in Tilapia Fish Pond with Solar Panel Source

Tilapia cultivation requires good management of water quality and proper feeding to ensure optimal fish growth. One of the main challenges in this process is maintaining the water pH level within ideal limits and providing feed according to the needs of the fish based on their size. In addition, limited access to electricity in some locations makes fish pond management less efficient. This study aims to design an automated water circulation system that is regulated based on the water pH level and automatic feeding according to the needs of the fish, by utilizing solar panels as a power source. This system uses a pH sensor to monitor water conditions in real time and regulate water circulation to maintain ideal pH levels. Feeding is regulated based on the size and number of fish to ensure optimal feed efficiency and fish growth. This system is powered by solar panel energy, so it can operate independently without relying on conventional electricity networks. Test results show that the system is able to maintain water pH stability and automate feeding with high accuracy, while utilizing renewable energy effectively. The use of solar panels not only reduces dependence on electricity, but also reduces operational costs and supports environmental sustainability. This system is expected to increase the efficiency and productivity of tilapia cultivation, especially in areas with limited access to electricity.

Preschoolers use probabilistic evidence to flexibly change or maintain expectations on an active search task.

This study investigated 3- to 5-year-olds' (N = 64, 37 girls, 62.5% White, data collected between 2021-2022) ability to use probabilistic information gleaned through active search to appropriately change or maintain expectations. In an online fishing game, children first learned that one of two ponds was good for catching fish. During a subsequent testing phase, children searched the ponds for fish. Half saw outcomes that were probabilistically consistent with training, and the other half saw outcomes that were probabilistically inconsistent. Children in the Inconsistent condition adapted their search strategies, showing evidence of changing their expectations. Those in the Consistent condition maintained their initial search strategy. Trial-by-trial analyses suggested that children used a combination of heuristic and information integration strategies to guide their search behavior.

Rancang Bangun Pakan Ikan Otomatis dan Kontroling Suhu Serta Monitoring pH Air Berbasis IoT

This research proposes the design of an automatic fish feeding system equipped withtemperature control and water pH monitoring based on the Internet of Things (IoT). Thissystem aims to increase efficiency in aquarium or fish pond management by integratingvarious control and monitoring functions in real-time. In this system, the automatic fishfeeder uses a programmable dispenser mechanism to provide feed in predeterminedamounts and times. Temperature control is carried out using temperature sensors andheating or cooling actuators, to maintain water temperature conditions within the optimalrange. In addition, water pH monitoring is carried out through a pH sensor connected tothe system to ensure the water quality remains ideal for fish health. Data from these sensorsis sent in real-time to the IoT platform, enabling remote monitoring and control via webbasedor mobile applications. The results of implementing this system show increasedefficiency in feeding, increasing operational efficiency, reducing human error, andproviding quality fish, as well as maintaining more stable and optimal environmentalconditions. The implementation of this system shows great potential in modern aquacultureapplications by utilizing IoT technology for better and responsive management.

The balance of carbon emissions versus burial in fish ponds: The role of primary producers and management practices

In the global carbon cycle, ponds can play a dual role: they have the capacity to store carbon through sedimentation, but also to be important greenhouse gas emitters. Of all the pond landscapes in Europe, many are managed by Humans for fish production and little is known today about their role as carbon sinks or sources. We monitored 20 fish ponds from the Dombes region (France) during a production season in 2022. We measured both sedimentation rates, the diffusion of CO2, CH4 and N2O and ebullition of CH4 over three different seasons (spring, summer and autumn) in order to provide an estimate of the carbon balance for each pond. Five were dried-out in 2023 as part of the management cycle, and were monitored for dry flux emissions during this period. On average, our measurements suggest that fish ponds were carbon sinks (6 fish ponds as sources and 14 as sinks). There was on average a net sequestration of 4.16 (+/- 10.00) tonnes of CO2e per hectare over 6 months. Measurements from the dry year, indicate that the ponds were carbon sources (mean value of 23.89 tonnes of CO2eq emitted). However, whilst the drying out phase directly increases emissions, it also encourages the development of macrophytes in the subsequent years which improves carbon storage through sedimentation, and appears to be an important driver of the observed balances. These data are consistent with the fact that fish ponds have the capacity to be either sources or sinks of carbon for the atmosphere. Moreover, by promoting good levels of primary productivity, the presence of aquatic plants and by improving carbon storage, management practices appear to have the capacity to turn fish ponds into carbon sinks. These agroecosystems could thus play an important role in the context of climate change mitigation.

Drying out fish ponds, for an entire growth season, as an agroecological practice: maintaining primary producers for fish production and biodiversity conservation.

Agroecology largely focusses on terrestrial agroecosystems, but it can also be applied to fish farming. Indeed, ponds are typically used for fish production in Europe, but are also important reservoirs of biodiversity. Numerous studies demonstrate that both fish production and biodiversity are strongly determined by human management. One key practice in extensive fish farming, although more rare in Europe, is to dry out ponds. They are left dry for a complete year after several years of fish production. However, the extent to which this practice affects the functioning of the ecosystem, its biodiversity and fish production remain unclear. We investigated data from 85 fish ponds in the Dombes region, France, sampled between 2007 and 2014. We related variation in key abiotic characteristics to the time since last dry out. The dataset included organic matter content in pond sediments and concentrations of inorganic nitrogen and phosphorus in the water column, and biotic components such as macrophytes cover and richness, phytoplankton concentration and richness, macroinvertebrates density, and fish yield. Our results show that drying out facilitates the mineralization of organic matter in sediments and results in higher concentrations of inorganic nitrogen in the water column. Macrophytes cover is highest during the first year after drying out, and gradually declines after at the expense of increasing phytoplankton concentration. The diversity of both is highest in the first year after drying out and declines rapidly, especially for macrophytes. Fish yield is at its maximum in the second year. Drying out fish ponds appears to be an important agroecological practice in extensive fish farming with an application every three to four years. By nutrient recycling, this practice has a positive impact on the balance between primary producers and indirectly on the whole food web during two years. It optimizes fish production and allows biodiversity conservation.

Land Use and Land Cover Change in East Java Indonesia from 1972 to 2021: Learning from Landsat

This study analyses land use and land cover (LULC) changes during the last five decades (1970–2021) in East Java Province, Indonesia. The changes are analysed by comparing four maps interpreted from Landsat images (MSS 1972, TM 1997, OLI 2013, and OLI 2021). The main research procedures consist of (1) data collection, (2) field survey, (3) image classification, and (4) LULC change interpretation. The classification uses the maximum likelihood algorithm, achieving an overall kappa accuracy of > 75%. The classification produces eight classes, i.e., built-up land (BU), heterogeneous agricultural land (HAL), bare soil (BS), paddy fields (PF), open water (OW), vegetation (VG), shrubland (SH), and wetlands (WL). The analysis shows a significant shift in land use from 1972 to 2021, with HAL declining by 46%, SH by 91%, and BS by 88%. In contrast, PF has increased by 105%, VG (forest and plantation) by 64%, and built-up areas by a remarkable 366%. These changes show a significant shift from dryland agriculture, shrublands, and barren lands to irrigated regions, vegetated areas, and urban growth. Furthermore, there are increases in water bodies due to the construction of several reservoirs to support water availability. In coastal regions, the development of inland aquaculture leads to a proliferation of wetlands (salt evaporation ponds, fish ponds, and rice-fish integrated farming).

Unraveling the pharmaceutical footprint and risks of combining different aquaculture modes and tailwater treatment systems

Aquatic environments serve as repositories for pharmaceuticals, and intensive aquaculture is becoming a significant contributor to the discharge of aquaculture wastewater. The cyclical footprint of pharmaceuticals between the aquatic environment and aquaculture has emerged as a global concern. The environmental occurrence and risk assessment of pharmaceuticals in the aquatic environment via various aquaculture modes, as well as the pharmaceutical removal efficiency in different tailwater treatment systems, have been studied through yearly investigations. Thirty-four pharmaceuticals were detected in the aquaculture environment, and the dominant pharmaceuticals were enrofloxacin, sulfamethoxazole, amantadine, and florfenicol. The highest concentration of pharmaceuticals was found in the fish pond (3826 ± 29.6 ng/L) under the greenhouse aquaculture mode, especially in the early and late aquaculture stages, and the same trend was observed in the pond aquaculture mode. The tailwater removal efficiency was greater in summer months than other months, and the treatment efficiency of the recirculating treatment system was more stable. During the aquaculture period, a low risk was observed for most pharmaceuticals, except for enrofloxacin, sulfamethoxazole, ciprofloxacin and ofloxacin, which had at medium to high risk. High-risk pharmaceuticals show a high potential to contaminate the surrounding aquatic environment and adversely affect associated biota. Reassuringly, the ecological risks of the detected pharmaceuticals can be effectively reduced after tailwater treatment. This study provides valuable data for the growing system to assess risk in aquaculture and serves as a reference to establish quality standards for aquatic products.

Student learning trajectories in finding the perimeter and area of a rectangular in the context of a fishing pond

Mathematics is a difficult subject for elementary school students. One of the causes is errors in mathematical concepts and principles made by students. For this reason, efforts need to be made to improve the concept and principles of quadrilaterals. The aim of this research is to design student learning trajectories in finding the perimeter and area of a rectangle in the context of a fishing pond. This is research with a design research approach. The subjects of this research were 50 students divided into two groups, 25 people each. Data collection techniques through observation, interviews and documentation. The data analysis technique used is qualitative and is developed through certain relationship patterns. The results of this research show that the mathematics learning trajectory design was implemented very well. It improves the ability of understanding about quadrilaterals. The learning path is activity-1: students create a representation of the context of a fishing pond and a rectangular image. Activity-2: students determine the perimeter of a rectangular image by placing match sticks around the rectangle in sequence, holding them tightly together. Activity-3: students determine the circumference of the fishing pond. Activity-4: students determine how to calculate the circumference of the pond by drawing a rectangle using matchsticks. Activity-5: students discover the principle of perimeter of a rectangle. The conclusion of this research is that the mathematics learning trajectory design is valid, practical, and increases the ability to understand concepts and principles from quadrilaterals.

Assessing Heavy Metal Contamination in Commonly Used Fertilizers for Polyculture Fish Ponds and Its Implications for Human Health: A Comprehensive Investigation.

Over-fertilizing fish ponds can cause pollution, introducing heavy metals into the food chain and posing health risks. The present study investigated the incidence of heavy metals (Pb, Cu, Cd, and Cr) in commonly applied fertilizers, including nitrogen, phosphorus and potassium (NPK), triple superphosphate (TSP), and di-ammonium phosphate (DAP), and their association with heavy metals in water, sediment, and cultured fish species (Catla catla, Labeo rohita, and Cyprinus carpio) in polyculture fish ponds. The study was conducted over 4months, with four groups in triplicates: control (no fertilizer), group 1 (NPK), group 2 (TSP), and group 3 (DAP). Heavy metal analysis was carried out using atomic absorption spectrophotometry before and after fertilizer application. Significantly (p < 0.05) higher levels of heavy metals were observed in water and sediment after applying fertilizers, with the most pronounced results in group 3 (DAP) followed by group 2 (TSP). The concentration of heavy metals was significantly (p < 0.05) higher in group 3 (DAP) fertilizers compared to other groups. Compared to the control, the concentration and bioaccumulation of heavy metals were significantly (p < 0.05) higher in the fertilizer-applied groups, with notably higher levels in group 3 (DAP). Cluster analysis and the correlation matrix did not show any significant association between the heavy metals and the fertilizers, indicating a complex interplay between the biotic and abiotic factors of the system. The health index (HI) value was < 1 in fish muscles of all studied groups, indicating the fish are safe for consumption. The study recommends monitoring and regulating fertilizer use, especially DAP, to prevent heavy metal contamination, and exploring sustainable alternatives to minimize environmental and health risks.

Spatial distribution of bacterial communities driven by environmental factors in the sediment of Lateolabrax japonicus ponds

Dynamic changes of bacterial communities in the sediment are very important for preventing diseases and water quality in aquaculture ponds. In this study, bacterial communities in the sediment of Sea perch Lateolabrax japonicus, an important farmed fish in China, ponds were studied using 16S rRNA Illumina sequencing and functional gene array. At the phylum level, Pseudomonadota, Actinomycetota and Chloroflexota were the dominant species. The bacterial community composition was different in spatial variation. Among the environmental factors, the concentration of nitrogen related factors (TN, NO3−-N NH3-N, NO2−N) and total organic carbon was the main impact on the composition of bacterial community, especially denitrifying bacterial community. Nitrifying and denitrifying bacteria accounted for 4.81 %, and bacteria related to nitrogen cycle accounted for 18.36 %. Higher diversity of bacteria in healthy fish pond than that of the diseased fish pond. In the diseased fish pond, lower abundance of Nitrosospira and higher abundance of Nitrobacter were found, and the contents of NH3-N, NO2−-N and total organic carbon were significantly higher. This study would help to reveal that microbial community structure could reflect the health of cultured animal and surroundings, and it could provide a theoretical reference for the healthy environments in the sediment of Sea perch ponds in South China.

Constructing recyclable SERS platform based on peroxidase-like Cu2O/g-C3N4/Ag composites for sensitive sensing of fungicides

In this work, we proposed a straightforward self-assembly and in-situ deposition protocol to construct Cu2O/g-C3N4/Ag composites, which demonstrated peroxidase-like attribute and exceptional SERS activity. These composites proved to be an effective SERS analysis tool for detecting organic fungicides like malachite green (MG) and crystal violet (CV). Remarkably, they achieved detection limits as low as 10−9 M in DI water as well as fish pond water, and exhibited a strong linear correlation between logarithmic concentrations and SERS intensities (R2 ≥ 0.97). Beyond that, with the aid of hydrogen peroxide (H2O2), the peroxidase-like Cu2O/g-C3N4/Ag composites rapidly degraded MG and CV molecules within just 5 min. Furthermore, their practical reusability based on the peroxidase-like reaction was proved by high SERS performance across 5 detection cycles. These results emphasize the immense potential of Cu2O/g-C3N4/Ag in SERS-based trace fungicide detection and suggest future applications in ecological restoration through peroxidase-like reactions.

Evaluation of the Physical and Chemical Properties of a Number of Aquarium Waters in Kirkuk Governorate and Determination of Bacterial Content of Pond Water

This study aimed to evaluate the fish ponds in the outskirts of Kirkuk, starting from the Hawija district, Daqouq, Lylan, Yayji and Taza, and the tests were conducted in the Department of Environment and Agriculture and included water samples of carb fish ponds. The physical, chemical and biological traits were measured for January 2024. The temperature recorded the highest value of 40 m in September in the first station. The highest value of electrical delivery was recorded in the September at the fifth station, as it amounted to 3.227 microscopes/cm and the lowest value of 0.477 microscopes/cm per month in the fourth station, and the results showed the high values of electrical conductivity at the fifth station in all study months. As for the values of the total soluble solid materials at the five study stations, the highest value of 1860 mg/l in November was recorded in the fourth station and the lowest value in the same station was recorded in August, the results showed the high values of the total solid materials in the fifth station in all months of the study. As for the values of Akkara, it ranged between 111-0.833 mg/l, and the highest value of 111 mg/l was recorded in the month of August in the fourth station and the lowest value of 0.833 mg/l in November in the first station, and it was noted through the table the high values The second in all months of the study, and the values of the pH in fish ponds ranged between 6.4-7.4, meaning that the water in the fish ponds tends to be a little alkaline, as the fifth station in the month of August was registered with the highest values of hydrogen, 7.4, and the value was recorded at the second station 6.4.

Water Quality Monitoring and Control System for Tilapia Cultivation Based on Internet of Things

This research analyzes the quality of water for tilapia habitat which is a type of brackish water fish that is currently widely cultivated by pond farmers. This fish is the choice because of its flexibility regarding habitat. However, despite having flexibility in terms of habitat, each harvest of tilapia that lives in a different habitat will produce tilapia with different quantity and quality. Currently, many tilapia farmers still carry out the cultivation process using traditional methods using ponds. Kuala Kerto Village, Lapang District, North Aceh is one of the locations where many tilapia fish farmers use ponds as a habitat for this fish. Not infrequently, changes in natural conditions such as rain and floods have an impact on tilapia fish ponds in this village. Thus, crop yields are very varied, often even resulting in losses. One of the reasons for this is that there is still minimal use of technology in tilapia cultivation in this village. The design of a water quality monitoring and control system for IoT-based tilapia cultivation in this research was carried out to help the problems of tilapia pond farmers. Through this research, a tool was produced in the form of a prototype IoT device that can be used to monitor and control water quality in tilapia fish ponds. This device utilizes several sensors such as turbidity sensors, ammonia sensors, salinity sensors, pH sensors, and several other sensors as data takers which will later be transmitted and displayed via a web application. Research and development of this device uses the RD method, namely research and development.

Soil carbon pools and microbial network stability depletion associated with wetland conversion into aquaculture ponds in Southeast China

Wetlands, which are ecosystems with the highest soil surface carbon density, have been severely degraded and replaced by artificial reclamation for fish and shrimp ponds in recent years. This transformation is causing intricate shifts in soil carbon pools and microbial stability. In this study, we examined natural wetlands and reclaimed aquaculture ponds in Southeast China to analyze the structure and network stability of soil microbial communities following the reclamation of estuarine wetlands and to elucidate the microbial-mediated mechanisms for regulating soil organic carbon (SOC). The aquaculture ponds presented significantly less average SOC content than the natural wetlands (p < 0.05). ACE, Chao1, and Shannon's indices of bacteria and fungi were decreased in aquaculture ponds. Less numbers of nodes and edge links in the co-occurrence network of soil fungi and bacteria in aquaculture ponds. This suggests reduced correlation and stability within the microbial network of aquaculture ponds. Decomposers in soil fungi (e.g. Dung Saprotroph) reduced. Reduced proportions of key phyla Ascomycota, Basidiomycota and Rozellomycota in the soil fungal network. Reduced proportions of key phyla Proteobacteria, Chloroflexi and Desulfobacterota in the soil bacterial network. In conclusion, our results suggest that converting wetland paddocks to intensive aquaculture ponds results in carbon pool loss and reduces soil microbial network stability. The results highlight the importance of protecting or moderately restoring mangrove wetlands along the coast of southeastern China. It is also predicted that such measures may enhance the storage capacity of soil carbon pools and improve the stability of carbon sequestration by soil microorganisms, thus offering a potential solution for mitigating global climate change.

Connection between the gut microbiota of largemouth bass (Micropterus salmoides) and microbiota of the aquaponics system environment.

The significant role played by the gut microbiota in fish growth, development, immunity, and overall health has been widely established. Nevertheless, there remains a lack of clarity regarding the interaction and origin between the environmental microbiota and the gut microbiota of aquaculture species within the aquaponics coupling system. Thus, we conducted an analysis of the gut microbiota of largemouth bass (Micropterus salmoides) obtained from an indoor enclosed circulating water aquaponics coupling system located in greenhouses in northern China. Additionally, we examined the microbiota of the fish pond water and tomato rhizosphere soil using high-throughput sequencing of the 16S rRNA gene. Our results demonstrated significant differences in the compositions of fish pond water, rhizosphere soil, and the gut microbiota of largemouth bass. Moreover, these compositions changed throughout the culture period. Approximately 11.99% of the bacterial composition in the gut microbiota of largemouth bass could be attributable to the rhizosphere soil microbiota, while 62.01% of the bacterial composition could be attributable to the fish pond water microbiota. However, the proportion of bacteria in the gut microbiota from the fish pond water microbiota remained respectively 40.90% and 56.15% in May and September, which increased markedly to 88.97% in July. Similarly, the proportion of bacteria in the pond water microbiota from the tomato rhizosphere soil microbiota were respectively 0% and 8.95% in samples collected in May and September, which increased markedly to 69.26% in July, and the proportion of bacteria in the gut microbiota from the tomato rhizosphere soil microbiota were respectively 0.07% and 0% in samples collected in May and September, which increased to 0.45% in July. The research results offer essential insights into the interactions and origins of environmental microbiota and gut microbiota in the aquaponics system of cultured fish. This knowledge could enhance green aquaponics practices for largemouth bass.

The impact of plant cryoextract on productivity and factors of innate immunity of pond fish against the background of stress in the experiment

The search for effective and environmentally friendly means to increase the productivity and natural resistance of animals, especially in aquaculture, remains an urgent socio-economic task. This article presents the results of the study of the effect of the cryobiological supplement ‘Immunolife-Fish’, based on medicinal plants, on the weight gain of juvenile common carp (Cyprinus carpio) and indicators of innate immunity of two-year-old common carp (Cyprinus carpio) and silver carp (Hypophthalmichthys molitrix) under the influence of thermal stress factor in aquarium conditions. It was found that the weight gain of juvenile carp treated with the cryobiological supplement ‘Immunolife-Fish’ was higher than that of the control group at all stages of the study. The increase was most pronounced during the first 42 days of feeding. A significant increase in the number of leukocytes was found in the blood of fish (common carp and silver carp) exposed to a heat stressor compared to control values. In fish that received a supplement of the herbal preparation during stress, this indicator only tended to increase. The effect of the stressor in fish of both species is manifested by a significant increase in the leukocyte content, a decrease in the indicators characterizing the functional state of cellular immunity — phagocytic activity and number of phagocytes, as well as a tendency to decrease the phagocytic index of neutrophils in the blood. The use of the cryobiological supplement ‘Immunolife-Fish’ in fish exposed to stress not only prevented the decrease in the phagocytic activity of neutrophils but also contributed to a slight increase in their activity in comparison with the control. A significant decrease in the activity of lysozyme and the level of circulating immune complexes, as well as an increase in the content of seromucoids, was found in the blood serum of common and silver carp under the influence of the stress factor. The use of the drug against the background of stress leveled the negative changes in the above indicators characterizing the state of the humoral link of innate immunity. In addition, a mild immune stimulating effect of the cryobiological supplement on fish of both species, which were kept in optimal conditions, was noted. The research is aimed at the development and testing of organic, environmentally friendly anti-stress and immunostimulant agents in commercial fish farming

Technological aspects of growing commercial trout on the basis of IP «Ak Balyk»

The materials for the preparation of the article were based on samples and observations taken at the stage of entering the IP "white fish".Research on this topic was carried out using hydrochemical methods, production technologies and evaluation of fish products.As a result of the study, it was found that:1. A fish pond with an area of 1.2 hectares, an average depth of about two meters with a fresh water supply of 16 liters/ sec.2. A basin area with a total water volume of 985.8 m3 and a water exchange rate of 46 l/sec, for commercial trout cultivation.There are no sources of anthropogenic impact and factors negatively affecting the ecology of the environment in the fish farming area of IP "Ak Balyk".According to hydrochemical indicators, the water on the farm meets the requirements for fish farming.