scholarly journals ESTIMATING EFFICIENCY OF POND ELECTRIC SEINE NETS OPERATION

Author(s):  
Dmitriy Alekseevich Kostrykin ◽  
Yulia Nikolaevna Grozesku

The article considers the problem of low productivity of many fish farms, especially non-drainage ponds against the background of a growing increase in the volume of fish farming, which is typical for pond fish farming in Russia. It has been found that one of the main factors of low productivity (1–5 c/ha) is the imperfection of existing tools and methods of fishing. With significant costs of manual labor and time, the catch of farmed fish is no more than 50%. The remaining fish die mostly during winter fish kills. To reduce the proportion of manual labor and improve the efficiency of fishing in non-drainage ponds, many countries are looking for the methods to modernize existing or develop new fishing gear. The most promising in this respect are electric breeders for fishing in the non-drainage ponds, small lakes and water reservoirs. The advantages of this method are the coverage of a large fishing zone, the possibility of catching fish leaving ordi-nary seines, and work in silted and tied water bodies. Studying the regularities of the electric field impact on fish is necessary to explain and predict its behavior in electric fields, to develop technical means that provide the necessary control activity, to develop measures to protect ichthyofauna from the harmful effects of electric fields, etc.

Agro-Science ◽  
2020 ◽  
Vol 19 (2) ◽  
pp. 36-40 ◽  
Author(s):  
J.E. Omeje ◽  
A.M. Sule ◽  
E.O. Aguihe

The study assessed aquaculture table-size fish farmer’s activities in the Kainji Lake basin, Nigeria. Specifically, the study examined aquaculture  activities in the area, assessed market information, channels and support organizations, and identified the major constraints to aquaculture table- size fish farming in the area. A two-stage sampling technique was used to select 120 table-size fish farmers. Primary data were collected with a questionnaire and presented using descriptive statistics. The result shows that majority of the respondents were males (82.1%), with mean age of 36.7 years, 53.8% had tertiary educational qualification while 66.7% had more than six years’ experience in fish farming. Majority (92%) of the table-size fish farmers operate with less than two ponds, 51% practice earthen pond system, while 91% of the farmers engage in the business for the purpose of generating income. Majority (90%) of the farmers sell their farmed fish after six months, 80% of the sales take place at farm-gate level, 80% of the owners of the fish farms are contacted directly by fish buyers. Also, majority (53.8%) of the fish buyers are the middle men who buy and resell to other fish users (processors, consumers, farmers etc). The major constraints to table-size fish farming were inadequate capital (46.2%), poor water management (33.3%), high cost of feed (10.3%) and poor pricing (10.3%). It is therefore recommended that fish farmers should form  strong Farmer Associations to enable them combat the issues of accessing capital and poor pricing. This will aid in business expansion as the farmers will take advantage of economy of scale. Key words: aquaculture, table-size, fish, farmers


Author(s):  
Dmitriy Alekseevich Kostrykin ◽  
Yulia Nikolaevna Grozesku

The article describeы the fishing process as a final technological stage that completes the cycle of fish breeding in the fish ponds. Fishing in the ponds, regardless of their category, is a difficult and energy-intensive process. The safety of farmed fish and the overall results of fish farming depend on the process of fishing. The well-known fishing methods are based on filtering fish when discharging water through fish catchers or other artificial structures. When water is drained from the pond, the fish moves to a fish catcher with the water flow, which contradicts its biological tendency to breast the current and prevents from its getting into the fish catcher or another artificial structure. In addition, the separation of fish from water by a grated water separator leads to the mechanical damage of the fish scales and reduces the number of alive fish. The technology of fish catching in draining ponds used at the small innovative enterprise SRK Sharapovsky (Kamyzyaksky district, Astrakhan region) has been analyzed. The absence of a fish catcher is a specific feature of the technology. Fishing in the ponds is carried out by using a dragnet during the pond drainage, starting the catch when the pond’s area is lowered to 1/3 or 1/4. The disadvantages of this technology include excessive accumulation of fish in a small volume of water, which can cause fish death or severe injuries to the underyearlings reared with commercial fish species. Choosing the optimal fishing gear or a device will allow to clearly plan and coordinate the work of the enterprise, because the fishing period is short and depends on the time frames and the market demands.


1995 ◽  
Vol 31 (10) ◽  
pp. 73-84 ◽  
Author(s):  
T. M. Iversen

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.


1995 ◽  
Vol 31 (10) ◽  
pp. 61-71 ◽  
Author(s):  
M. Enell

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.


2021 ◽  
Vol 11 (6) ◽  
pp. 2534
Author(s):  
Henrike Rebl ◽  
Claudia Bergemann ◽  
Sebastian Rakers ◽  
Barbara Nebe ◽  
Alexander Rebl

The present study provides the fundamental results for the treatment of marine organisms with cold atmospheric pressure plasma. In farmed fish, skin lesions may occur as a result of intensive fish farming. Cold atmospheric plasma offers promising medical potential in wound healing processes. Since the underlying plasma-mediated mechanisms at the physical and cellular level are yet to be fully understood, we investigated the sensitivity of three fish cell lines to plasma treatment in comparison with mammalian cells. We varied (I) cell density, (II) culture medium, and (III) pyruvate concentration in the medium as experimental parameters. Depending on the experimental setup, the plasma treatment affected the viability of the different cell lines to varying degrees. We conclude that it is mandatory to use similar cell densities and an identical medium, or at least a medium with identical antioxidant capacity, when studying plasma effects on different cell lines. Altogether, fish cells showed a higher sensitivity towards plasma treatment than mammalian cells in most of our setups. These results should increase the understanding of the future treatment of fish.


Author(s):  
F. A. Altayeva

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.


Author(s):  
A. M. Naumova ◽  
◽  
L. A. Rozumnaya ◽  
A. Yu. Naumova ◽  
L. S. Loginov ◽  
...  

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.


Author(s):  
T. Umamaheswari ◽  
M. Rajakumar ◽  
P. Chidambaram

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.


Author(s):  
Farhan Yasin Hamed ◽  
Adelia Zakirovna Anokhina ◽  
Natalia Viktorovna Sudakova ◽  
Damelya Kazhigalievna Magzanova

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.


Author(s):  
Grigory Emelyanovich Servetnik

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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