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The present study was undertaken to evaluate the effect of market economy conditions on the economic results of fish farms. Data collected from 1992 to 1998 were analyzed. Sample sizes for various indices, separately for pond and lake farms, ranged from 69 to 123. Six indices were chosen for the analyses, including financial liquidity (current and rapid), cost level, return (on sales and total assets) and labor efficiency. The direction and statistical significance of trends were evaluated using correlation coefficients. No negative trends were observed for any index, while positive trends were found for the following: index of current financial liquidity; rapid liquidity index; labor efficiency for lake farms; return on total assets and labor efficiency for pond farms. The overall economic efficiency was higher for pond farms.
Background. Poland is one of the largest common carp producers in the European Union. By 2006, the annual production of carp and other cyprinid fish species had reached around 17 000 t. The economic efficiency of pond farms is not only significant for the performance of Poland’s traditional carp market, but it also supports the non-productive environmental functions of earthen carp ponds. The objective of this study was to determine the costs and revenues of carp ponds, and to identify the key conditions for improving the profitability of carp farming in Poland. Materials and Methods. Data from 2005–2007 were collected through a survey of 18 carp farms keeping full accounting records of a total pond area of 17 302 ha, accounting for around 34% of the total in Poland. Data was both biological and economic. The former consisted of survival rate of different age groups of fish. The latter included farm revenues (sales of carp and other species, angling fees, and other income sources) and annual production costs. The cost was separated into two main parts, variable- and fixed costs. The income was determined by subtracting the annual total cost from the total revenue. The profitability was defined as the cost-to-income ratio. The results were compared with available economic indicators of carp production in Germany and Hungary in 1999–2002. Results. The proceeds from the sale of market-size carp had a predominant share of total revenues of the investigated farms. The variable cost consisted of labour (37%) and feed (20%), while the share of the remaining cost components did not exceed 10% of total expenses of fish farms. Only in 2007 was pond fish production profitable (merely 3.95%) while in 2005 and 2006, the total costs of the farms were higher than their revenues (on average –7.42% and –2.42%, respectively). The average survival rates of stocking carp in the studied farms, including fry between 0 and 2 years of age, were very low at 36% and 38%, respectively. The survival rates of market-size carp were much higher, on average 67%. Conclusion. The economic situation of Polish carp farms, within the studied time period, was difficult. The low survival rates of stocking carp seemed to be one of the main causes for the low return on carp production. This may be a compound effect not only of epizootic diseases but also of piscivorous animals and environmental restrictions imposed on carp ponds. Farmers could find it difficult to reconcile fish production with the pond environmental functions and the need to maintain a healthy profit margin without external financial support.
The current study explores the possibility that multiple fish farms (FFs) containing sea bass (Dicentrarchus labrax) and sea bream (Sparus aurata) can be successfully integrated within a semi-enclosed bay in the Croatian Adriatic. The research focuses on determining principal environmental factors (EFs) that control the integration and attempts to estimate their individual and synergic ability to influence deposition and removal of organic matter (OM) and trace elements (TE) from the system. The complexity of the designated tasks demanded a comprehensive number of various datasets and samples to be used in the analysis. The ADCP data revealed strong wind induced currents forming within the research domain resulting in high system flushing efficiency (3.5—6 days). The sediment samples from all stations contained relatively inert minerals which contributed to overall low OM and TE concentrations and very limited variability found across the entire bathymetric range. The thermal advection effect recorded at two stations was attributed to specific seabed topography and the hydrodynamic response formed during Maestral wind episodes. The results indicate that a successful integra- tion of four FFs has taken place within the research site (semi enclosed bay), and that the key EFs responsible for its success are strong wind induced hydrodynamics, favorable seabed topography and sediment mineral composition. The synergy of the principal EFs that formed within the system was found to have an attenuating effect regarding FFs chemical influence (OM and TE) and an amplifying one regarding spatial footprint which extended to = 2000 m distance.
Background. Fish farming has been developed due to decline of traditional fishing where tilapia culture is one of the principal sources for fish production. This study was aimed to investigate the prevalence and impact of helminth infection on the health of cultured hybrid tilapia, Oreochromis sp. Materials and Methods. Prevalence and intensity of helminth infection and histopathological response of infected organs were studied. Changes of biochemical composition, and protein electrophoritic pattern, and heavy metals levels of liver and muscle tissues were determined. Results. Helminth infection was restricted to the liver of 60% of the examined fish. Of this number 33% were infected by undifferentiated nematode larvae and heterophyid metacercariae while 67% showed the metacercarial infection only. Infection caused a noticeable alternation in histological architecture of the liver that was accompanied by depletion in hepatic glycogen, total lipids, and total protein. Moreover, biochemical components of the muscle tissues were significantly decreased along with intensity of infection. Protein fractions of the liver and muscle tissues were highly variable. Intensity of the parasitic infection was directly correlated with Fe and Mn levels in both liver and muscle. Conclusion. s. Cultured fish also suffered from helminth infection that significantly impaired the health and condition of fish as shown by histopathological, biochemical, and protein fractions changes recorded in this study. In additions, intensity of helminth infection might increase the capacity of infected organs in accumulation of heavy metals.
The aim of this study was to describe a case of skin lesions with haemorrhaging in a carp (Cyprinus carpio) hatchery farm and to determine effective antibiotic treatments. In the macroscopic examinations of nine carp with haemorrhagic skin lesions, brown or red spotted skin changes of a varying degree were found, along their bodies. No lesions were observed in the internal organs. Pure cultures of Aeromonas hydrophila were isolated from the skin, kidney, heart, and liver of the carp. All of the isolates were found to be susceptible to danofloxacin, enrofloxacin, gentamicin, ciprofloxacin, neomycin, and trimethoprim-sulphamethoxazole and resistant to ampicillin, amoxicillin, amoxicillin/clavulanic acid, oxytetracycline, and streptomycin. Treatment of A. hydrophila infection was carried out by applying trimethoprim-sulphamethoxazole for 3 d at 10 g/ton of pool water.
Induced gynogenesis as potential tool for detection of receive deleterious mutations carriers salmonids fishery . 8 rainbow trout females were tripped and the eggs were subjected to induced gynogenesis procedure. Approximately half of 3 female’s progeny showed type of malformations occasionally observed in rainbow trout stock kept in Rutki Station. The case study describes the potential usefulness of gynogenesis as breeding test to reveal carriers of harmful recessive alleles.
One hundred and twenty-six isolates of Yersinia ruckeri originating from different species of fish were collected: 122 from rainbow trout (Oncorhynchus mykiss; Walbaum), three from pike (Esox lucius L.), and one from carp (Cyprinus carpio L.). The O- serotyping of the isolates were carried out for the first time in Poland by microplate agglutination assays according to the Davies procedure. Three O-serotypes were determined: O1, O5, and O7. Serotypes O2 and O6 have not been recognised. Almost all isolates were represented by serotype O1, which originated only from rainbow trout showing classical clinical signs of enteric redmouth disease. The strains representing serotype O5 were only collected from pike and serotype O7 from carp and rainbow trout showing no clinical signs of the diseases.
Following the spread from its origins in China, Asian lineage highly pathogenic avian influenza H5N1 was first recorded in Europe in Turkish poultry and in poultry and wild birds in Romania in early October 2005. On 19 October 2005 Croatia became the second European country to record an outbreak in wild birds, involving Mute Swans Cygnus olor. Subsequent surveillance in Croatia revealed further instances of H5N1 in dead and sick Mute Swans in 2005, and in 2006 in more dead Mute Swans and in living, apparently healthy, Black-headed Gulls Larus ridibundus, but not in poultry. The observations presented here suggest that Croatia experienced two independent incursions of Asian lineage HPAI H5N1, but genetic confirmation is not available. Potential routes of introduction by wild birds, the poultry industry and fish-farming practices are discussed, but the evidence for all of these remains circumstantial
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