Aquaculture Objects Research Articles

Monitoring of Coastal Aquaculture Sites in the Philippines through Automated Time Series Analysis of Sentinel-1 SAR Images

With the unprecedented expansion of aquaculture around the world, there is a critical need to monitor its progress. In Palawan, Philippines, coastal aquaculture is gaining momentum towards increasing fish production, a pressure that presents a challenge to the sustainability of these areas. In this paper, we explore the application of Earth observation methods to map coastal aquaculture development in Palawan and evaluate the extent of its change. The European Space Agency Sentinel-1 synthetic aperture radar and Sentinel-2 multispectral instrument sensor data were applied in fully automatic mode to build maps of Palawan coastal aquaculture. The maps were validated using Google Earth high-resolution optical images and in situ observations in Malampaya Sound, and demonstrated a successful detection rate of 72%, while the false alarm rate was less than 7.5%. Objects only 5 m across, four times smaller than the spatial resolution of the Sentinel-1 sensors, were successfully detected using the developed methodology, thus exceeding the capabilities of other published methods that are limited to detecting large groups of aquaculture structures. The maps revealed aquaculture structures in high quantities in Malampaya Sound, Taytay Bay, and other locations in the coastal waters of Palawan, Philippines. A significant change of aquaculture spatial distribution was identified by comparing aquaculture maps generated with an interval of three years. This new automated methodology was validated as robust for mapping aquaculture objects in Palawan, Philippines, and can be applied to aquaculture studies in other regions worldwide.

On the Development of Long-Range Water Quality Monitoring System for Outdoor Aquaculture Objects

Abstract The paper is dedicated to the development of hardware and software components for the autonomous water quality monitoring system (WQMS) for fishing farms. The system can measure main water quality parameters, storing and processing data on the remote server. The LoRaWAN technological solutions and infrastructure are utilized, providing the optimal tradeoff between data transmission range and adaptive power consumption. The main implementation and exploitation issues are described, and the proposed solutions are provided.

Taxifolin Modulates Transcriptomic Response to Heat Stress in Rainbow Trout, Oncorhynchus mykiss.

Simple SummaryCultivated rainbow trout face with multiple stressors that impact their viability, growth, and welfare. Heat stress provoked by summer temperature rise leads to increased mortality and accelerated transmission of bacterial and parasite pathogens in fish population. Feed supplements of plant-origin could alleviate stress in fish presumably via stimulation of their defense systems. To understand the mechanism of beneficial effects of taxifolin, an antioxidant extracted from larix wood, we compared transcriptomic responses to both temperature rise and flatworm infection in rainbow trout individuals fed either a standard ration or supplemented with taxifolin. Dietary taxifolin has been shown to mitigate some heat-induced responses in fish, such as biosynthesis of sterols, heat-shock proteins, and cell death regulators, while it does not interfere with temperature-dependent antioxidant induction. Interestingly, no transcriptomic response was induced due to Gyrodactylus infestation in trout, whereas parasite load was diminished due to heat treatment. Thus, the plant-origin supplementation of fish diet could be an easy way to improve the health of fish and promote their ability to tolerate stresses under intensive production.Taxifolin is a natural flavonoid known for its antioxidant, anti-inflammatory, and antiproliferative effects on animals. In this work, we have studied the effect of this compound on rainbow trout, Oncorhynchus mykiss, a major object of aquaculture, under slowly increasing ambient temperature and Gyrodactylus flatworm infection. Transcriptomic profiling of liver samples performed by using the Illumina HiSeq 2500 sequencing platform shows that a combined taxifolin/heat treatment, unlike heat treatment alone, downregulates the production of isopentenyl diphosphate, likely affecting the production of cholesterol and other sterols. Taxifolin treatment also modulates multiple apoptosis regulators and affects the expression of HSPs in response to increasing temperature. On the other hand, the expression of antioxidant enzymes in response to heat is not significantly affected by taxifolin. As for the Gyrodactylus infection, the parasite load is not affected by taxifolin treatment, although it was lower in the high-temperature group. Parasite load also did not induce a statistically significant transcriptomic response within the no heat/no taxifolin group.

Применение нейронных сетей в системе распознавания промысловых гидробионтов в условиях повышенной флуктуации

The article focuses on using artificial neural networks for the recognition of commercial hydrobionts in conditions of increased fluctuation. Research has not been conducted in the field of recognition of aquaculture objects for reasons of solving the applied problems and achieving the required indicators. There is described the development of software for recognition of aquaculture objects based on the YOLOv5 model, as well as the proper methodology for the semi-automatic formation of effective visual training samples. There has been analyzed the model operation scheme and substantiated the importance of the training sample and its influence on the quality of pattern recognition by a neural network. Effective identification of aquatic organisms requires the methods for dividing it into zones according to various distinctive features and separating the required objects not only from the background, but also taking into account fluctuations above the water surface. There has been developed a method for eliminating fluctuations in order to increase the efficiency of recognition of aquatic organisms by a neural network. There is described the process of testing software for the detection of commercial hydrobionts trained on a sample by the proposed method. 
 It has been inferred that the recognition rate directly depends not only on the quality of the training sample and the volume of images, but also on the technical characteristics of the electronic computer

The effectiveness of the use of astaxanthin in production feeds for promising aquaculture objects

When developing the composition of recipes for complete dry combined feeds in industrial aquaculture, in addition to their balance in terms of basic nutrients, it is necessary to pay attention to the presence of a number of irreplaceable biologically active feed components in them. Among them, along with vitamins and minerals, are carotenoids – natural pigments contained in the natural food of fish. Carotenoids – play a different role in the metabolism of fish and are also pronounced antioxidants that protect the body from the action of free radicals. The article discusses the experience of using the natural antioxidant astaxanthin in feeding tilapia. Astaxanthin is a powerful antioxidant that has a huge impact on the functioning of all systems and overall health. But this practice has not affected mass thermophilic aquaculture species like tilapia, their muscle tissues and caviar are not stained under the action of astaxanthin, and its effect on the physiological status of fish, as well as antioxidant properties have not been studied. It was found that the addition of astaxanthin – 20.0 and 40.0 mg/ kg to the composition of production feeds allowed to increase productivity by 22.0 and 39.2%, respectively, as well as to have a positive effect on the physiological state of fish.

Development of safety system in salmon fish farms of the Murmansk region

The study presents the development of a biosafety system in aquaculture activities on the territory of the Murmansk region, accounting for the existing scientific developments and recommendations. The authors’ scientific and practical experience in cultivating the hydrobionts in the conditions of the Polar region is the core of the study. The materials for the development of the regional biosafety program of salmon cages farms were the longstanding epizootic and ichthiopathological studies of the department of fish physiology and diseases, aquaculture objects of the Murmansk Regional Animal Disease Control Center (2013–2019). The most significant risks for salmon net farms of the Murmansk region are: carrying out activities in the zone of risky fish farming; lack (or scarcity) of high-quality nursery material of domestic origin, absence of the center for research and prevention of fish diseases; the absence of the specialized enterprise for aquaculture waste disposal. The developed system of practical safety of aquaculture enterprises in the region will allow managing the risks through certain efforts and events. The principles of biosafety system development in accordance with the environmental requirements and associated conditions for maintaining the epizootic and ichthyopathological safety in the commercial cultivation of fish are considered. Preventive measures to maintain epizootic safety in fish farms have been developed. Suggestions and recommendations are formulated to conduct safe aquaculture activities in the conditions of the Murmansk region. A integrated approach to biosafety through certain risk management activities is aimed at solving the problems of preserving the health of cultivated objects resulting in the maximal feasibility of the enterprise and maintaining the biodiversity of natural communities and environmental sustainability in the region.

Assessment of ecological conditions for growing the market-size fish in the Kantivka fattening pond (Khmelnychchyna, Ukraine)

Abiotic (water quality) and biotic (Phyto-, zooplankton and benthos) factors in the Kantivka fattening pond the Khmelnitskrybhosp Private Joint-Stock Company were studied during the vegetation seasons in 2020. The aquaculture objects in the pond are cyprinid fish species (carp, grass carp, silver carp, pike). The ecological conditions of the pond were evaluated as good enough for the fish fattening purpose. The critical water quality parameters were following traditional values accepted for fish farming in Ukraine. The taxonomic composition of plankton and benthos was represented by widespread and Ubiquiti species mainly. The 124 species and intraspecies taxa of microalgae and the 34 species of zooplankton were identified in the Kantivka fattening pond. The mean abundance and biomass for the phytoplankton were 183.8 million cells/dm3 and 35.61 mg/dm3, respectively; for zooplankton, those were as 336600 ind/m3 and 14.83 g/m3, and for zoobenthos, those values were as 309.6 ind/m2, and biomass as 5.84 g/m2. Such parameters of natural forage base correspond to the optimal values for natural fish food according to fish farming standards in Ukraine. In the late summer, the free-living copepod stages and mature adult females of the parasitic copepod crustacean Ergasilus sieboldi Nordmann were registered in plankton. This copepod causes the invasion of fish diseases like infection and destruction of gill arches, which leads to a severe disturbance in fish respiration, emaciation, delaying in growth, and the potential death of commercial fish even. The development of natural fish food in the Kantivka fattening pond is shown an intensive level of biomass and abundance of phytoplankton, zooplankton, and zoobenthos. It is considered sufficient to meet the natural nutritional needs (in combination with artificial feeding) for older age groups of the cultivated cyprinid fish species.

Высокотехнологичные приемы переработки рыбного сырья, выращенного в Астраханской области

The modern level of development of fish processing technology is analyzed. A number of high-tech processes related to deep processing of aquaculture objects (paddlefish, clary catfish and tilapia), grown in the Astrakhan 
 region, in closed water supply installations, have been proposed for implementation. The chemical composition of fish muscle tissue has been studied. A method has been developed to reduce the microbial contamination of raw materials using a low-frequency electromagnetic field. Methods of electrophysical and gas-liquid processing of raw materials have been adapted to real production conditions. Methods for processing secondary fish resources into edible fish meal and fish oil have been tested using gas-liquid technologies. Methods for processing water and muscle tissue of fish raw materials by electromagnetic and gas-liquid methods are proposed. The chemical composition of fish pates enriched with CO2-extracts was investigated.

Обґрунтування використання гуматів в аквакультурі (огляд)

Purpose. To prepare a justification for the use of sodium and potassium salts of humic and fulvic acids (humates) as substances with biologically active properties in fish feeds based on the analysis of sources of scientific and technical information and own experimental materials, Findings. A complex general characteristic of humic substances was provided, the mechanism of biologically active action of humates on living organisms was described. Examples of the use of humates in crop production, medicine, animal husbandry and aquaculture were given. The results of our own studies on the use of humates as a feed additive for valuable objects of aquaculture were presented. Prospects for the inclusion of micro-additives of sodium and potassium humates in the composition of fish feed in order to increase fish survival and digestibility of feed were outlined. Originality. To date, the introduction of humates into fish feed as micronutrients was experimental. The analysis of scientific sources and materials of own studies gave the basis for the conclusion about the need of complex detailed studying of mechanisms of effects of humates on fish. In particular, it is of interest to study the protective properties of humates from the accumulation of heavy metals in the body of fish for the use of micronutrients of these substances in fish feeds. Practical value. The use of humate feed additives in aquaculture will help to solve such urgent problems as the prevention of excessive losses of biological material of cultivated objects, reduction of feed costs, improvement of consumer characteristics of food products. Humates, as substances of natural origin with protective and immunomodulatory action, can become substitutes for some synthetic therapeutic and prophylactic drugs. Key words: aquaculture, humates, compound feed, feed additive, growth rate, survival, feed assimilation.

Перспективы культивирования белоногой креветки Penaeus vannamei (Boone, 1931) в различных регионах России с учетом гидрохимических характеристик водоемов и сезонной динамики температурных показателей

Whiteleg shrimp Penaeus vannamei (Boone, 1931) is one of the most popular and promising objects of world aquaculture. In this article possibilities and prospects of cultivating this species in Russia, the results of studies of temperature and salinity effects on the survival rate, growth, activity and food intake of white-footed shrimp were discussed. The critical values of temperature and salinity for this species have been determined. The most progressive for whiteleg shrimp cultivation are the southern regions of Russia, which have an extended sea coastline or a lot of hyperhaline or brackish waterbodies. Technologies combining commercial pond rearing with preliminary rearing of juveniles in RAS are recommended to use to increase the efficiency of cultivation.

On the issue of Australian crayfish cultivation in ponds to ensure sustainable aquaculture development

The authors of this article describe the experience of biotechnology for growing Australian crayfish in conditions of pond cultivation in a group of ponds, operating in an intensive mode, used in an isolated area close by a natural water source in the Astrakhan region. In the presented article, research is aimed to clarify the main biotechnological indicators that increase the efficiency of cultivation in pond conditions. The conditions of transportation, the duration of transportation, and the density of crayfish in ponds with an area of 1 hectare have been clarified. The presented food recipe with the specification of the percentage of nutrients as additional feeding, organized when growing in ponds according to the food recipe itself, increases not only the growth rate but also the hemolymph protein concentration, which indirectly proves the satisfactory conditions for keeping aquaculture objects. Monitoring for the biotechnology of growing Australian crayfish in pond conditions: own developed food recipe, biological and physiological testing of key indicators such as hydrochemical indicators of water, hydrobiological indicators of the concentration of, and physiological indicators for determining the so-called biotechnological norm, which will add additional missing information on this aquaculture object.

STUDY OF THE EFFECT OF FEED ADDITIVE OF SODIUM HUMATE FOR STERLET BY THE CAGE METHOD OF GROWING

The article presents the results of an experiment to assess the effect of feed additive of humates on the growth rate and survival of different age groups of sterlet (Acipenser ruthenus L., 1758) and the conversion of fish feed for keeping in aquaculture. Based on the analysis of sources of scientific and technical information, it was found that humic drugs have long been used in crop production as growth stimulants and microfertilizers, and in animal husbandry - to normalize metabolism, treatment of digestive diseases and general stimulating effect on the body as a whole. Analysis of data on the use of humates in aquaculture indicated the presence of a positive effect of these compounds on individual cultivation objects. The small amount of information on the use of humates in fish farming has led to the conclusion that this direction of fish farming intensification is still insufficiently studied, and that studies of the impact of humic substances on aquaculture objects are not comprehensive and mainly concern the assessment of individual effects of biologically active action of the compounds on fish. The available information gave grounds to speculate about the prospects for the use of humates in sturgeon farming. To test this assumption, a series of experiments was conducted on the feeding of sterlet feed with the addition of sodium humate. The research was conducted in 2018, 2020 and 2021, in the production conditions of the cage fishery, located on the Kaniv Reservoir. The effect of different concentrations of sodium humate feed additives on one- and two year old sterlet was evaluated. It was found that the addition of sodium humate to fish feed in concentrations of 60, 100, 120 and 200 mg / kg of feed did not significantly affect the growth rate of sterlet. Thus, the advantage of experimental variants over the control for this indicator was insignificant, in the range of 1.0-1.6%. The effect of sodium humate on the survival of this year sterlet, for their cultivation in gardens. At the same time, the best, by 6.7-17.4%, feed conversion with the addition of humates by one- and two-year-old sterlet was noted. According to the results of the experiments, the best result was obtained in the variant using a feed additive of humates at a concentration of 200 mg / kg of feed. It is considered promising to continue the study of the impact of feed additives of humates on the growth and survival of valuable aquaculture objects under different housing conditions, in particular in closed recirculation aquasystems (RAS), as well as finding the optimal concentration of these additives in feed for different species and age groups of fish.

Bioindicators of homeostasis’ constants of growing conditions of warm-water aquaculture objects in the context of obtaining marketable products

To create recommendations regarding the technological process of growing objects of warm-water aquaculture, the health of individuals in the created conditions of maintain is a necessary study. Taking into account the similarity of the necessary conditions for the organization of growing warm-water aquaculture objects, it is important to monitor the indicators that are bioindicators of homeostasis constants with a projection on the conditions of maintain, for subsequent adjustment of satisfactory conditions of maintain. First of all, these are hematological and biochemical bioindicators that determine the general characteristics of blood in the case of fish objects of sterlet and hemolymph in the case of crustacean objects of Australian freshwater crayfish and the concentration index of total serum protein that determines the “physiological norm”. When growing sterlet, a high level of total blood protein was established at 40.14±1.73 g/l and the hemolymph of the Australian freshwater crayfish was determined to have a protein concentration of 40.8±4.5 g/l. The presented analysis of bioindicators complements the missing information for monitoring the data of representatives of warm-water aquaculture, which will be valuable for specialists engaged in breeding these objects.

Potency and Strategy of Aquaculture Development in Rokan Hilir Regency, Province of Riau, Indonesia

Rokan Hilir Regency is situated east coast of Sumatera in Riau Province. Fish production of the area dominated by capture fisheries (80.67%) compared to aquaculture production (19.33%), however, there is a demand for strengthening the role of aquacuture. This study aimed to analyze the prospects and strategies for developing aquaculture in this area. Primary data was obtained by measuring of water quality, observations of aquaculture objects and other supporting facilities. Interviews and discussion were conducted with fish farmers, community leaders, the fishing industry, local government officials and other stakeholders. Secondary data were obtained from government and private institutions. This area has the potential for freshwater aquaculture of 102.80 ha, brackishwater aquaculture of 3,049.25 ha, and marine aquaculture of 118.330 ha. In 2019, aquaculture only utilized an area of around 2,879,107 ha, including 47,107 ha of freshwater (ponds), 10 ha of brackish, and 2,822 ha of shellfish ponds. Aquaculture production in 2019 was 15,006.34 tons consisting of fish production from ponds (blood clams and shrimp) 9,009.34 tons which was the main production, followed by fish production from ponds of 5,997 tons. In coastal waters, it is recommended to cultivate blood cockles and Pacific white shrimp (Litopenaeus vannamei). While in inland waters, the recommended fish culture included tilapia (Oreochromis niloticus), striped catfish (Pangasianodon sp), kissing gouramy (Osphronemus sp), and African catfish (Clarias gariepenus), both in ponds and floating net cages. The recommended development strategies include; training on aquaculture human resources, training on making their own feed, building seed and brood centers, and providing business stimulants in the form of seeds, making ponds and floating net cages as well as sustainable guidance from the fisheries industry and the government.

Legal regulation of introduction in Ukraine

The article considers the peculiarities of the legal regulation of introduction. The basis for research in this area is that among the anthropogenic factors that negatively affect the structural elements of the ecological network, biological and landscape diversity in general, at the present stage should be noted scientifically unsubstantiated introduction of individual flora and fauna. That is why the legal regulation of these relations and the consolidation of both a clear terminological apparatus and a proper legal mechanism for their implementation, which will allow the national legislation to regulate the introduction of all kinds, is becoming relevant. This article outlines the provisions of national and international legislation in this area, as well as the meaning of the terms "introduced species" and "invasive species" and their relationship in terms of law. The legal classification of introduction is given, its value for legal standardization of ecological relations is revealed. The author substantiates the need to develop a single categorical-conceptual apparatus for regulating relations in the field of implementation of all natural objects. This work becomes especially relevant given that today among scientists there is no single approach to the relationship we are considering, moreover, there is no independent research in this area. It is established that relations in the field of introduction occupy a special place in environmental legislation, as they can be considered in the context of the use and reproduction of natural resources, as well as the protection of biological diversity and the environment as a whole. Equally important, the legal regulation of the introduction depends not only on the introduced objects, but also on the purpose and method of introduction (for example, to regulate the number of objects of fauna, flora, aquaculture or introduction to reproduce forests, etc.).

Bioindicators of the constants of homeostasis of the internal environment of crustaceans, cultured in different environmental conditions for the purpose of obtaining commodity products

The study of the composition and properties of the internal environment (hemolymph) of crustaceans grown in various conditions has an important ecological and physiological aspect, since a number of characteristics of the physiological status of objects can be used to assess the state of the environment, thus, they can be included in the number of bioindicators. However, the nature of the observed differences between objects grown under different conditions, the features of homeostatic regulatory mechanisms and the limits of the reference values of individual homeostasis constants are often not known. To formulate recommendations regarding the technological process of growing objects of warm-water aquaculture, taking into account the assessment of environmental conditions in dynamics through the analysis of indicators of the state of individuals — bioindicators — it is necessary to compare the state of individuals kept in different conditions. The object of the study was the Australian red claw crayfish Cherax quadricarinatus (Von Martens, 1868), cultivated under various conditions of intensive and semi-intensive cultivation. The studies have revealed that throughout the entire period of cultivation, individuals grown in ponds retained a high level of total protein, cholesterol and β-lipoproteins, in contrast to crayfish cultivated in pools. The values of these indicators as bioindicators indicate a high degree of compliance of the growing conditions with the needs of the studied object. Comparative assessment of fluctuations in the ratio of hemolymph shaped elements in the hemocyte composition between cancers grown under different conditions did not reveal significant differences. It was found that significantly higher growth rates are characteristic of crayfish grown in ponds, in contrast to the group of individuals cultivated in pools. The comparative analysis of bioindicators in different growing conditions presented by the authors of the article supplements information that is of significant interest for monitoring the growing conditions of this representative of warm water aquaculture, which will be valuable for specialists engaged in crustacean breeding.

Особливості застосування гіпохлориту натрію для регенерації високопористих наповнювачів після їх використання у біофільтраційних системах установок замкнутого водопостачання

Purpose. Development of a method for the regeneration of highly porous fillers for biofilters after slagging of their pores with biofilm residues in the process of growing aquaculture objects in recirculating aquaculture systems (RAS). Methodology. Regeneration of fillers was performed with solutions of sodium hypochlorite of different concentrations (2.5%, 1%, 0.5% of active chlorine) after their exploitation for 6 months. The cleaning efficiency was monitored by the difference in fillers weights after cleaning. Findings. According to the study, the use of sodium hypochlorite for cleaning highly porous fillers for biofilters (using an example of porous ceramic filler and foamed glass «JBL Micromec») is efficient and cost-effective. A reduction in the weight of the test samples averaged 12.95% for porous ceramics and 15.01% for foamed glass. Based on the obtained data, aqueous solutions with different concentrations of sodium hypochlorite do not have a pronounced difference in efficiency, respectively; the optimal for use is a 0.5% solution. Originality. The use of highly porous fillers for biofilters has long been unprofitable in fish farming due to the rapid loss of their main advantages - a high specific area per unit volume as a result of micropore slagging with biofilm residues. As a result, complete regeneration of these filter materials was required annually, which, given the significantly higher cost compared to polymeric fillers, made their use unprofitable. The described technique allows the use of porous ceramics and foamed glass, after their restoration, for a long time, with replacement only after mechanical wear. Practical value. The described method allows using highly porous fillers for biofilters in the process of growing aquaculture objects without their main disadvantage - a rapid decrease in efficiency as a result of pore slagging with biofilm residues. Keywords: RAS, biofilter, filler, restoration, sodium hypochlorite.

JUSTIFICATION OF THE INNOVATIVE METHOD OF PRELIMINARY PROCESSING OF FISH RAW MATERIALS

The scientific article presents experimental data on the possibility of modification of the generally accepted traditional technology of pre-heat treatment of freshwater fish raw materials in the production of canned fish by developing an innovative method - dehydration with hydrochloric acid. Technological and rheological features of the muscle tissue of the object of study - silver carp, which is the most important object of aquaculture and commercial fish farming in Ukraine and in many other countries, require the use of pre-heat treatment. This technique is required to remove moisture from muscle tissue by denaturing sarcoplasmic proteins when the temperature rises above 95 C. Due to the high specific heat of fish muscle tissue, heat treatment is energy intensive and, consequently, not cost effective. In connection with the above promising direction of modification of preliminary heat treatment of raw materials of the fish industry in the production of canned fish should be the development and implementation of a new innovative energy-saving method of processing semi-finished products in the design of modern fish processing enterprises. The paper presents data on the effect of hydrochloric acid on the properties of muscle tissue of silver carp. This directional regulation of the moisture holding capacity in the direction of its reduction is possible by shifting the pH to the isoelectric point of muscle tissue proteins. The influence of such technological parameters as mass fraction of hydrochloric acid in the treatment solution, hydromodule (solution: raw material), temperature and duration of the process on the change of active acidity of muscle tissue of fish raw materials, and, accordingly, moisture binding capacity was established. Accordingly, the following technological parameters of the process were determined: mass fraction of hydrochloric acid - 0.1%, processing temperature 20–25°С, hydraulic module - 1:10, processing duration - 30 minutes. The introduction of the developed technological parameters of the innovative method of pre-treatment creates conditions in which the active acidity of muscle tissue is as close as possible to the isoelectric point of most fish proteins, which in turn provides minimum values of moisture binding capacity. Based on the obtained data, a technological method of pre-processing of fish raw materials in the production of canned fish has been developed, the use of which allows to completely eliminate energy-intensive thermal operation from the technological cycle, and accordingly significantly increase economic efficiency

According to the issue of the giant freshwater prawn ((<i>Macrobrachium rosenbergii</i>)

Purpose: study the biotechnical features of rearing juvenile giant freshwater prawn (Macrobrachium rosenbergii) using recirculating aquaculture systems (RAS).Materials and methods. Two fish-farming modules RAS and aquarian complex were used for the work. One of them has a total volume of 6.5 m3, the second - 14.5 m3. Larvae were reared in gasite cages of 0.021 m3 in an aquarian complex of two 200-liter aquariums. Larvae of one female prawn were used in an amount of 8500 units. At each stage of prawns' development we used different versions of feed of both animal and plant origin: artemia, minced fish, boiled chicken eggs (protein + yolk), beef liver and oat flakes.Results. Brood fish were kept at an average planting density of 6.2 individuals/m2, with a sex ratio of 1:4.5 (males: females). The planting density of larvae in cages was 2,125 units/cage or 101.2 units/liter. The average weight of juveniles during rearing of postlarvae at 130 days was 3.19 g. Juvenile yield was 49.9%. Specific growth rate of biomass varied from 4.87 to 3.68 %. Planting density of juveniles varied from 1775,6 units/m2 to 660,9 units/m2. As a result, the feeding coefficient was 5.24 units. Growing productivity was 362.7 pcs/m2 or 1156.8 g/m2 in the RAS module.Conclusion. There were established biotechnical peculiarities and production possibilities of growing young giant freshwater prawn (Macrobrachium rosenbergii) using fish-breeding RAS and aquarian complex. Modernization of fish-feeding RAS and use of some recommendations on feeding suggest the possibility of their use for breeding and rearing of juvenile giant freshwater prawns in already existing warm-water enterprises, initially aimed at other objects of aquaculture.

ЭЛЕМЕНТЫ ЦИРКУЛЯРНЫХ ТЕХНОЛОГИЙ В АКВАКУЛЬТУРЕ

The elements of circular technologies in aquaculture on various types of energy are considered. The development of forms of aquaculture from pasture to industrial with an increase in the share of circular technologies is shown. It is noted that the use of cage fish farming on the waste warm waters of energy facilities is complicated by eutrophication at high fish planting densities and the peculiarities of temperature and hydrochemical regimes. The need to select new aquaculture objects with a fast growth rate, thermophilic and not demanding to the oxygen content in the water is noted: the African clarias catfish (Clarias gariepinus) is a promising object for growing in warm waters. The possibilities of including other representatives of catfish - shilbovye catfish (Pangasius) - are considered. It is shown that due to the expansion of biotechnologies for growing valuable objects in installations with a closed water supply cycle, thermophilic hydrobionts, for example, the Australian red-clawed crayfish Cherax quadricarinatus, can be used as elite delicatessen products. It is shown that the complex hydrobiocenosis of fouling is formed by a set of consults of different orders. A fish-breeding system with elements of circular technologies becomes similar in structure to a natural ecosystem. The results of experimental cultivation of spicy vegetable crops on the waste products of carp and clary catfish are presented. Aquaculture and aquaponics as specific components of the modern agricultural sector in development are focused on industrial production technologies with the use of circular technologies for the efficient use of resources.