scholarly journals Occurrence of Cyanobacteria and microcystins in hydroelectric reservoirs used for fish farming

2020 ◽  
Vol 18 (6) ◽  
pp. 983-994
Author(s):  
Maria Fernanda Falcone-Dias ◽  
Marianna Vaz Rodrigues ◽  
Jeppe Lund Nielsen ◽  
Nadieh de Jonge ◽  
Niels O. G. Jørgensen ◽  
...  
Keyword(s):  
Negative Impact ◽  
Aquatic Organisms ◽  
Fish Farming ◽  
Fish Farms ◽  
Hydroelectric Reservoirs ◽  
Copy Numbers ◽  
Gene Copies ◽  
Mcye Gene ◽  
Microcystin Production ◽  
Aquaculture Production

Abstract Fish farming can have a negative impact on water quality and aquatic organisms due to emerging blooms of Cyanobacteria and the production of cyanotoxins. In this study, the effect of aquaculture in hydroelectric reservoirs in Brazil was evaluated in six fish farms and in upstream and downstream water through analysis of the microbiome, Cyanobacteria and microcystin concentrations. Synechococcus and Microcystis were observed at all six locations, while Limnothrix was also observed abundantly at two locations. An increase in the relative abundance of Cyanobacteria inside the fish farms was observed at two locations, while an increase of Cyanobacteria was observed in downstream at five of the six locations. Microcystins were detected in significant and high values in all locations, with concentrations up to 1.59 μg/L. The trend in microcystin concentrations was mirrored in copy numbers of the mcyE gene (encodes microcystin synthetase) and presence of Microcystis, but not in any of the other observed cyanobacterial groups. In summary, the study shows that aquaculture production influenced the water microbiome inside and downstream the fish farms, and a direct correlation was found between mcyE gene copies, microcystin production and abundance of Microcystis, but not for the total abundance of Cyanobacteria.

scholarly journals Medicinal and prophylactic measures against bacteriosis in fish farming

2021 ◽  
Author(s):  
L.N. Yukhimenko ◽  
S.B. Tokareva ◽  
M.S. Kukin ◽  
L.I. Bychkova
Keyword(s):  
Negative Impact ◽  
Morphological Changes ◽  
Morphological Characteristics ◽  
Fish Farming ◽  
Coliform Bacteria ◽  
Physiological Status ◽  
Forage Production ◽  
Fish Farms ◽  
Prophylactic Measures ◽  
Resistant Strains

The article reflects the negative impact on the microbiocenosis of water, fish and the environment of the uncontrolled use of antibacterial drugs, under the influence of which foci of late autumn aeromonosis (Moscow region) and summer pseudomonosis (Rostov region) are formed in fish farms, opportunistic microorganisms: Aeromonads, Pseudomonads, Acinetobacteria, Moraxella, coliform bacteria change their morphological characteristics (capsules are formed in coliform bacteria and Moraxella, the swarming phenomenon characteristic of Proteus - in Acinetobacteria) and increase their virulence. Along with this, there is a large number of resistant strains of bacteria, antibiotic-dependent mutants in those farms where several courses of antibacotherapy were conducted, the active substance of which is ciprofloxacin, morphological changes in the skeleton were noted in fish, the spine acquired an S-shaped shape, and pinpoint hemorrhages appeared on the liver, like from a needle prick. Resistant strains acquire not only epizootic, but also epidemiological significance, especially for people working in the field of fish farming and forage production, because resistant strains by conjugation can transfer their R-factor of multiple resistance to any strains, which has now become a worldwide problem, according to WHO. In such a situation, the main method of struggle is prevention, increasing the immune-physiological status of fish by using probiotics, high-quality compound feed, creating conditions for a comfortable fish keeping. If a course of antibiotic therapy was carried out during the outbreak, then it is imperative to carry out a 7-10-day course of feeding with a probiotic.

scholarly journals Fundamentals of commodity fishery for the cultivation of silver carp in polyculture with carp in the conditions of the LLC “Kovcheg” of the Kyiv

2021 ◽  
Vol 23 (95) ◽  
pp. 87-95
Author(s):  
V. Palamarchuk ◽  
G. Lyotka ◽  
V. Hlavatchuk
Keyword(s):  
Silver Carp ◽  
Aquatic Organisms ◽  
Fish Farming ◽  
Ecological Condition ◽  
Raw Material ◽  
Scientific Article ◽  
Material Base ◽  
Fish Farms ◽  
Fish Stocks ◽  
Artificial Reservoirs

This scientific article describes the technology and stages of designing a fishery for growing silver carp in polyculture with carp in conditions of the LLC “Kovcheg” of the Kyiv. In the conditions of this economy the project of cultivation of fish in polyculture was developed, where calculations of average monthly temperature of ponds, content of dissolved oxygen in water were carried out, indicators of a source of water supply of ponds were analyzed, economic efficiency of cultivation of silver carp in polyculture with carp was carried out. Fish farms have a number of significant problems today, that prevent full and easy development – these are financial difficulties in the state, namely: disruption of economic ties, deterioration of the ecological condition of inland waters, insufficient work on the reproduction of fish stocks. In order to get fish farming out of the crisis, ensure sustainable development of the industry, strengthen the country's food independence, it is necessary first of all to solve issues related to environmental and economic problems of fisheries development, improving the economic mechanism of fisheries management, intensification of investment processes and innovations aquatic living resources. The fisheries sector includes the extraction, processing, reproduction and increase of stocks of fish and other aquatic organisms in natural and artificial reservoirs. It provides valuable food, feed, medicine and technical products. Fisheries are aimed at preserving and improving fish stocks in natural reservoirs and breeding fish in artificial reservoirs. In order to ensure food security of Ukraine, it is necessary to work on the following areas: scientific substantiation of the raw material base and rational fishing, protection of aquatic ecosystems, technology of processing of aquatic fish resources.

Vaccines for aquaculture overview

2020 ◽  
pp. 42-43
Author(s):  
Andrey S. Khishov ◽  
◽  
Galina I. Burlakova ◽  
Keyword(s):  
Antimicrobial Agents ◽  
Aquatic Organisms ◽  
Animal Husbandry ◽  
Well Being ◽  
Pharmaceutical Drugs ◽  
Short Development Time ◽  
The Creation ◽  
Basic And Applied Research ◽  
North And South America ◽  
Aquaculture Production

Aquaculture production is a promising direction for the development of food production. Like traditional types of animal husbandry, it needs effective medicines for veterinary use, which would ensure not only the well-being of farmed aquatic organisms, but also increase the safety of the fish products and non-fish objects of fishing. The development of measures to control epizootic processes in aquatic organisms is impossible without the creation of new immunological preparations. The development and use of immunobiological drugs will reduce the use of antimicrobial agents. The corresponding set of pharmaceutical drugs was transferred from the traditional veterinary medicine, but due to the peculiarities of the biology of aquatic animals, their immunity and the characteristics of specific pathogens, this could not be done with biological products. The short development time in the aquaculture industry poses current challenges in the form of a lack of basic and applied research for relatively poorly understood groups of new pathogens. The immunological processes associated with the development and intensity of the immune response in aquatic organisms require a detailed study. For domestic aquaculture producers, the analysis and dissemination of the experience accumulated by mankind and the application of advanced developments in this area are even more relevant, since Russia is just beginning its path of intensifying aquaculture production. At the same time, it is clear that the prohibition of the use and monitoring of antimicrobial agents in food products and feed requires a change in the approach to the problem and will lead to the creation of new immunobiological drugs. The market for immunobiological preparations for aquaculture is the most promising for development. In the article, the authors provide data on the development and registration of vaccines for aquaculture in Europe, North and South America.

Fish farming in Denmark: environmental impact of regulative legislation

1995 ◽  
Vol 31 (10) ◽  
pp. 73-84 ◽  
Author(s):  
T. M. Iversen
Keyword(s):  
Organic Matter ◽  
Environmental Impact ◽  
Freshwater Fish ◽  
Aquatic Environment ◽  
Action Plan ◽  
Fish Farming ◽  
Fish Farms ◽  
Nitrogen And Phosphorus ◽  
Local Impact ◽  
The Impact

The main environmental problems associated with fish farming in Denmark are attributable to the dam, the “dead reach” and nutrient and organic matter discharge. The environmental regulation of fish farming in Denmark started with the Environmental Protection Act of 1974, the Statutory Order of 1985 forbidding wet feed, and the Action Plan on the Aquatic Environment of 1987. In the case of freshwater fish farms, the latter was implemented through the measures stipulated in the 1989 Statutory Order on Fish Farms. The impact of Danish legislative measures to reduce and regulate the environmental effects of freshwater fish farms can be summarized as follows: - the number of fish farms has been reduced from about 800 in 1974 to about 500 at present; - production has tripled since 1974 and has been stable since 1989; - a change from wet to dry feed has reduced the environmental impact of the farms; - the national goals of the Action Plan on the Aquatic Environment of 1987 for reducing fish farm discharges of organic matter, nitrogen and phosphorus have been fulfilled. The main remaining problems are that: - the local impact of fish farms on downstream stream quality is still much too high in about 15% of cases; - the problem of the passage of migrating invertebrates and fish is still unsolved at some farms; - the problems posed by “dead reaches” are still unsolved. It is concluded that sustainable fish farming is possible in Denmark, but with the present technology production will have to be significantly reduced.

Environmental impact of nutrients from nordic fish farming

1995 ◽  
Vol 31 (10) ◽  
pp. 61-71 ◽  
Author(s):  
M. Enell
Keyword(s):  
Major Part ◽  
Fish Farming ◽  
Fish Farms ◽  
Feed Composition ◽  
The North ◽  
Comprehensive Development ◽  
The Baltic ◽  
Inland Water Bodies ◽  
The Impact ◽  
Feed Coefficient

During the last 20 years there has been an interesting development of the Nordic fish farming, with regard to the feeding and farming technology and to the increase in production quantities. During the period 1974-1994 the production increased from 15,800 to about 250,000 tonnes/year. In 1974 the major part of the production was in Denmark, and in 1994 the major part was in Norway. The nutrient impact of fish farming on surrounding sea areas is mainly a function of the feed coefficient, the feed composition and metabolic processes in the fish. The comprehensive development of the feed composition and the feeding technology has resulted in reduced load of unmetabolized nutrients from fish farms, calculated per tonne fish produced. In 1974 the mean Nordic feed coefficient was 2.08 and in 1994 the coefficient was 1.25. Feed coefficients of 1.0-1.1 are now reported for Danish and Norwegian freshwater and marine fish farms. The nitrogen (N) and phosphorus (P) content of the feed has decreased, in addition the quality of the nutrient substances in the feed has changed, especially for N. The N content has decreased from 7.8 to 6.8% during the period 1974-1994 and the content of P has decreased from 1.7 to 0.7% during the same period. This development of the feed coefficient and the feed composition has resulted in a present load from a typical Nordic fish farm of 55 kg N and 4.8 kg P/t fish produced. The figures for 1974 were 132 kg N and 31 kg P/t fish produced. The Nordic fish farming production in 1994 resulted in a load of about 13,750 t N and about 1,200 t P on the actual recipients. The load from the Swedish, Finnish and Danish fish farming operations, with the Baltic Sea and the Skagerrak as the recipients, is negligible in comparison with other pollution sources. The quantities of N and P from the fish farming are equal to 0.5% of the atmospheric deposition on the sea surface and 3% of the atmospheric P load. Norwegian, Icelandic and the Faroe Islands fish farming operations are using the North Sea and the Norwegian Sea as the recipients. However, the nutrient load from single fish farms in certain coastal and inland water bodies can be significant and must be considered in the impact assessment together with other sources.

Growing commodity tilapia in various experimental conditions

2020 ◽  
pp. 26-36
Author(s):  
F. A. Altayeva
Keyword(s):  
Fish Farming ◽  
Biological Indicators ◽  
Fish Farms ◽  
Experimental Conditions ◽  
Fish Breeding ◽  
Closed Water ◽  
The Republic ◽  
Short Time ◽  
High Fish ◽  
Experimental Ponds

The article presents the results of growing tilapia to marketable weight in experimental sites (Chilikskoye pond pond farms LLP, KATU named after S. Seifullin JSC and Kapshagai spawning farm — 1973 LLP). In the process of carrying out research works, the methods generally accepted in fish farming, hydrochemistry, hydrobiology, hydrology, ichthyology, as well as foreign normative and technical guidelines and methodological instructions on the technology of growing commercial tilapia in industrial conditions were used. Monitoring of hydrochemical analyses of water in ponds, swimming pools, and closed water supply installations is given. Fish-breeding and biological indicators of tilapia grown in various experimental conditions are presented. The results of the studies have shown the real possibility of growing tilapia in various conditions of fish farms in Kazakhstan. Based on the results of the work, the following conclusions were made: — satisfactory fish-breeding indicators were obtained with various cultivation technologies (as when growing tilapia in polyculture and monoculture in ponds, in pools, as well as cultivation in the recirculation system); — the cultivation of tilapia in the experimental ponds of the fish farm of the Almaty region of the Republic of Kazakhstan has shown the possibility of obtaining high fish-breeding biological indicators of tilapia and the ability to grow to marketable mass in a short time; — as a result of experimental cultivation in various conditions, it was found that the survival rate was not lower than 97%; — as a result of the analysis of the profitability indices of the developed technologies, it was found that the most profitable was the technology of growing marketable tilapia products in monoculture ponds on water with a natural thermal regime in Chilik Pond Economy LLP.

PREVENTIVE MEASURES IN BREEDING FISHING FARMS: ECOLOGICAL AND VETERINARY ADDITIONS

2018 ◽  
Vol 1 (1) ◽  
pp. 84-89
Author(s):  
A. M. Naumova ◽  
◽  
L. A. Rozumnaya ◽  
A. Yu. Naumova ◽  
L. S. Loginov ◽  
...  
Keyword(s):  
Preventive Measures ◽  
Fish Farming ◽  
Fish Health ◽  
Fish Farms ◽  
Scientific Publications ◽  
Commercial Fish ◽  
Fish Products ◽  
Contagious Diseases ◽  
Veterinary Research ◽  
Significant Damage

The influence of ecological, epizootological and technological factors on fish health was studied. It is shown that disregard of environmental, technological and veterinary-sanitary requirements in the reproduction and cultivation of fish leads to the emergence of contagious and non-contagious diseases and causes significant damage to fish farming. The analysis of previously approved veterinary and sanitary rules, instructions, recommendations for breeding and commercial fish farms, as well as patent documentation and scientific publications in the field of ecological and veterinary research in fish farming is carried out. The possibility of using modern ecological and veterinary-sanitary achievements for the protection of fish health is shown. The complex system of preventive measures (organizational, environmental-technological and veterinary-sanitary), supplemented by modern ecological and veterinary achievements, in its implementation will allow to reduce losses of fish products and increase efficiency of production.

scholarly journals Economics of ornamental fish farming industry in Madurai District, Tamil Nadu

2017 ◽  
Vol 64 ◽  
Author(s):  
T. Umamaheswari ◽  
M. Rajakumar ◽  
P. Chidambaram
Keyword(s):  
Tamil Nadu ◽  
Sampling Technique ◽  
Fish Farming ◽  
Ornamental Fish ◽  
Expected Profit ◽  
Profit Margin ◽  
Fish Farms ◽  
The Cost ◽  
Farming Industry ◽  
Ranking Technique

India has enormous potential for the development of ornamental fish business. Although the country has conducive environmental conditions for breeding and culture of ornamental fishes, its share in export of ornamental fishes is less than 1%. The present study was undertaken to address the constraints prevailing in ornamental fish farming. Study was carried out among 44 ornamental fish farms in Madurai District, Tamil Nadu by adopting random sampling technique. The selected farms were classified into small (<0.5 ha) and medium farms (0.5-2 ha) and the data were collected by personally interviewing the fish farmers. The study attempted to analyse the socio-economic characteristics of respondents, existing supply chain, constraints involved in ornamental fish farming, annual revenue loss due to major constraints, treatment cost and expected profit margin. Various constraints were classified as production, marketing and others and were ranked using Garrett ranking technique. Tabular and percentage analyses were used to estimate the cost of treatment, revenue loss and expected profit margin. Four types of marketing channels were observed in the study area. Disease outbreak was found to be the major constraint faced by the farmers and hence, the revenue loss was estimated for the same. The annual revenue loss was found to be higher for the small ornamental units when compared to medium farms, which showed higher profit margin than small ornamental fish farms.

Modern features of aquaculture of cyprinids in the republic of Iraq

2020 ◽  
pp. 6-14
Author(s):  
Farhan Yasin Hamed ◽  
Adelia Zakirovna Anokhina ◽  
Natalia Viktorovna Sudakova ◽  
Damelya Kazhigalievna Magzanova
Keyword(s):  
Silver Carp ◽  
Stocking Density ◽  
Fish Farming ◽  
Pond Water ◽  
Government Support ◽  
Bighead Carp ◽  
Ctenopharyngodon Idella ◽  
Natural Food ◽  
Hypophthalmichthys Molitrix ◽  
Fish Farms

It is shown that the leading role in the aquaculture of Iraq belongs to Cyprinids, which account for over 80 % of all fish farming production. The most widespread in the country are four main world species of carp aquaculture: common carp (Cyprinus carpio), grass carp (Ctenopharyngodon idella), silver carp (Hypophthalmichthys molitrix) and bighead carp (Aristichthys nobilis). Basically, the traditional technology of growing Cyprinids in ponds is used, which includes the main fish farming processes: care of broodstock to prepare them for spawning, collecting eggs and milt, eggs fertilization and incubation of embryos, raising juveniles and marketable fish. Currently, there are about 2 thousand private fish farms, which have ponds of various sizes from 4 to 100 hectares. Cultivation of Cyprinids in Iraq is carried out mainly by extensive methods: the use of the natural food base of reservoirs with low fish stocking density in polyculture. The fish productivity of ponds varies greatly in different fish farms from 1,5 to 6 t/ha, which is due to economic reasons. The data on changes in the temperature of pond water during the year and hydrochemical indicators are given, which shows favorable conditions for Cyprinids rearing. Information on the use of compound feeds for growing carp in ponds is provided, and data on the composition and nutritional value of the feed used. The fish culture indicators for the main biotechnical processes of the rearing of four Cyprinid species in Iraq are described in detail. In the conclusion, it is indicated that for the effective development of aquaculture in Iraq, government support is needed in the form of a developed long-term program and legislative acts.

Polyculture in fish farming as a method of preventing fish diseases

2021 ◽  
pp. 30-40
Author(s):  
Grigory Emelyanovich Servetnik
Keyword(s):  
Fish Species ◽  
Fish Habitat ◽  
Fish Farming ◽  
Natural Food ◽  
Total Biomass ◽  
Fish Farms ◽  
Fish Diseases ◽  
Host Body ◽  
Contagious Diseases

Methods of prevention of fish diseases are aimed at destroying parasites in the host body and in the fish habitat — in the reservoir (chemoprophylaxis, increasing fish resistance), at preventing parasites from entering the reservoir (limiting the import of fish, import of healthy fish, quarantine measures, etc.), as well as preventing their spread and entry into the host body. It is shown that polyculture is not only the most effective method of using the natural forage base of the reservoir and, as a result, increasing fish productivity, but also a means of preventing mass infectious and other fish diseases. To prevent mass infectious diseases of fish and death from them both in safe and unfavorable ponds of carp fish farms, it is advisable to grow other fish species together with carp that do not suffer from diseases peculiar to carp. As a result, so-called sparse species plantings of fish are created in the ponds, while the total biomass remains high. At the same time, the natural food supply of ponds is most fully used and a kind of biological buffer is created that prevents the emergence and spread of contagious diseases. Polyculture can play a particularly important role in pond farms that already have certain problems with rubella, filometroidosis, botryocephalosis, carp pox, etc. Long-term studies of breeding herds in pond farms have shown that most of them have single foci of diseases, which, if there are optimal conditions for the pathogen, are ready to immediately respond with an outbreak of the disease or are generally quarantined for a particular fish disease. When determining the objects of polyculture, it is necessary to reduce the proportion of fish species that have a significant number of common diseases.

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