Purpose. Fisheries has a strategic importance for supplying the population with food, while the sectors of the national economy with raw materials, for strengthening the country’s position in the international arena, for preserving spatial and national integrity of Ukraine, plays an important role in the restoration of natural resources and in the increase in employment. In recent years, fisheries sector of Ukraine is in a severe, protracted economic crisis. Considering its socio-economic and strategic importance for the state, there is a task for developing an effective policy for fisheries development in Ukraine that defines the relevance of the research and practical importance of its results. Thus, a compilation and analysis of the existing information on the current state and development of fisheries sector in the crisis period will allow a deeper understanding of problems in the fisheries sector in Ukraine and finding quick solutions. The main goal of the state policy in the field of fisheries in Ukraine has to be meeting the needs of the population in fish and fish products by creating conditions for effective operations and development of aquaculture and fishing enterprises.
Findings. The article reviews the current state of the development of fisheries sector in Ukraine, consumption, catch, processing of fish and seafood, dynamics of fish product exports and imports, legislative and regulatory framework of fisheries sector, state of the implementation of WTO and EU requirements, as well as finding ways for the fisheries sector out from the crisis.
Originality. This work is a compilation of the information on the current state of fisheries sector development in Ukraine. The information is provided in the form of a coherent presentation of information on the current state of fisheries sector in Ukraine, both in the domestic and foreign markets.
Practical Value. The fact that the fisheries sector of Ukraine is still in a depressive state calls for further search of effective ways for creating and implementing the public policies for its development. This review of data and statistical information can be used in the planning and implementation of reforms to address such complex issues as finding ways for the fisheries sector of Ukraine out from the crisis and ensuring its further development in the coming years.
Keywords: fisheries sector of Ukraine, import, export, crisis, WTO, EU.
Purpose. To analyse the current state of fisheries in Dnipropetrovs’k region and elaborate a strategy of their development for the period of 2015–2019.
Methodology. We used the summarized results of hydrobiological, ichthyological and toxicological studies carried out during 2010–2014. Data were collected in the Zaporizhzhia reservoir and small water bodies with standard sampling gears. A set of control gears (gill nets with mesh size of 30–120 mm) was used to investigate the fish fauna. Juvenile fish were caught in the third decade of July – first decade of August with 10 m beach seine.
Findings. The analysis of fisheries in Dnipropetrovs’k region for the past five years showed that the disorder and absence of scientifically-based approach to fisheries processes as well as the low level of professional training of aquatic resource users resulted in low fish productivity in the majority of reservoirs, which ranged within 25–30 kg/ha that was several times less than the real potential fish productivity.
The proposed Conception of fisheries development provides a set of coordinated measures aimed at ensuring sustainable use, effective protection and restoration of aquatic biological resources, fisheries management based on natural, economic and environmental conditions of different types of water bodies. The developed practical measures allow increasing the amounts of fish product supply to the internal consumer market by at least 5 times without any environmental damage, expanding its assortment and reducing the costs by 25–30%.
Originality. For the first time, the Conceptual approaches to the regional management of aquatic biological resources in the conditions of specific human impact were introduced. They are aimed at implementing the scientific rationale of the measures for their rational use, artificial restoration, reclamation, etc.
Practical value. The proposed Conception is to provide the food requirements of the population of Dnipropetrovs’k region in fish products of domestic origin at scientifically based consumption norms.
Keywords: fisheries, Zaporozhzhia reservoir, water bodies of Dnipropetrovs’k region, hydroecological condition, fish productivity, artificial reproduction.
Purpose. To analyze the role of piscivorous birds of Podiceps genus in the ecology of Erysipelothrix rhusiopathiae bacteria.
Methodology. The serological examination of birds was performed using E. rhusiopathiae growth test reactions with blood on filter paper. The method of successive dilutions was used to prepare samples with 2.0 cm3 of nutrient medium containing serum concentrations of 10.0; 5.0; 2.5; 1.3; 0.6 and 0.3%. Each sample contained 0.05 cm3 of the daily culture of pathogenic bacteria E. rhusiopathiae as an antigen and was cultivated at 36.7±0.3°C. The results were recorded after 24 hours.
Findings. The extensiveness of Podiceps cristatus infection was 47.1%, whereas that of Podiceps grisegena was 22.2%. Young birds were less affected by E. rhusiopathiae than adults. The infection rate was 4.9 times higher in adult P. cristatus birds (70.0%) than in the young ones. All seropositive birds P. grisegena belonged to the adult age group. There was no relationship between the birds’ sex and the extensiveness of E. rhusiopathiae infection rate. P. cristatus feeding mainly on fish had a greater risk of getting infected with pathogenic bacteria E. rhusiopathiae than P. grisegena.
Originality. Serological studies of erysipelas in ichthyophagous birds of Podiceps genus have been conducted in Ukraine for the first time.
Practical value. Piscivorous birds of Podiceps genus play an important role in the ecology of pathogenic bacteria E. rhusiopathiae. Erysipelothrix bacteria can not only rapidly multiply in the body of a bird, but more importantly, they can be transferred long distances between reservoirs. Thus, trophic, topical and phoric relationships are formed between P. cristatus, P. grisegena and E. rhusiopathiae. The ability of piscivorous birds to transmit pathogenic bacteria from one reservoir to others should be considered when carrying out the activities aimed at preventing and eliminating erysipelas diseases in people and farm animals.
Keywords: Erysipelothrix rhusiopathiae, Podiceps cristatus, Podiceps grisegena, biocenotic relationships.
Purpose. To analyze major biological characteristics of pike (Esox lucius L., 1758) stock in the lower Dnieper River in the conditions of transformed flow.
Methodology. Collection of the ichthyological material was carried out in the lower Dnieper River from commercial fishing gears, including beach seines, drag seines, fyke-nets. Field, laboratory processing of samples and mathematical analysis of the obtained results were carried out according to generally accepted methods and guidelines with some assumptions regarding the duration of pike fattening directly in the lower Dnieper River.
Findings. Recent years, there is an increase in the specific weight of younger age groups in the pike stock in the lower Dnieper River. Analysis of linear growth indicates on satisfactory environmental conditions for pike. Current commercial contingent of pike is based on size classes of 46–50 cm versus 22–32 cm in the first half of the last century. Reproductive properties of pike, in particular fecundity, egg size and maturity coefficients did not virtually change compared to those of the last century. Depending on linear sizes, the absolute fecundity is 32.3–155.8 thousand eggs and the maturation coefficient is 11.1–15.7%. Morphologic variability of pike in the lower Dnieper River during the period from 1980s to the present time was observed for plastic features, which characterized fin sizes. Sexual dimorphism in current conditions was observed only for maximum body depth. No significant differences for other plastic features between males and females of pike in the lower Dnieper River.
Originality. The data on biological characteristics of pike stock from the lower Dnieper River have been updated. Current fecundity of females of different size groups recorded in commercial catches was been determined. An analysis of morphological variability of major plastic features of pike in the process of the transformation of the Dnieper River flow has been carried out.
Practical value. The determined peculiarities of pike linear growth will allow optimizing commercial harvest for preserving the most productive part of the stock. Such measures will contribute to an increase in the commercial stock of this valuable predatory fish of the Dnieper-Bug mouth system that in turn will ensure appropriate regulation of the number of coarse non-commercial fish. This is highly important for the balanced trophic strain for valuable commercial species at early stages of their development.
Key words: lower Dnieper River, Dnieper-Bug mouth system, predatory fish, pike, linear growth, size classes, fecundity, morphologic variability.
Purpose. To characterize the morphometric and morphologic peculiarities of peled grown in ponds of the aquaculture farms “Okonsk” and “Korop” for creating the initial brood stock for its further use for broadening species diversity in fish farms of Ukraine.
Methodology. The study materials were the young-of-the-year and yearlings of peled obtained from the eggs imported in March 2008 from Russian Federation. According to Pravdin’s method, 27 plastic features, which are used most frequently for biological and systematic analyses, have been examined. The analysis of plastic features was carried out in the system of absolute values and in the index system – as percentages of the body length by Smith. Based on the analysis of the features, we examined their mean values (M± m), deviation (δ), and coefficient of variation (Cv).
Findings. Based on the obtained data and available literature data, we carried out a comparative analysis of morphometric features of young-of-the-year peled grown in pond conditions of Polissya and Prykarpattya. An analysis of plastic and meristic features of yearlings with young-of-the-years has been conducted. A comparative analysis of the morphometric features of the yearlings reared in the conditions of Polissya with those of native water bodies from literature data has been carried out.With an increase in the body length in experimental fish, there is a decrease in the highest and lowest body depth values, anterodorsal distance, head and eye lengths, an increase in the values of pectoventral, postdorsal, anteanal distance and the dorsal fin height. Compared to fish from native water bodies, the examined fish are characterized by an increase in the snout length, eye diameter, head length, caudal peduncle length; a decrease in the anteanal, anteroventral, ventral distances, length of the base and height of the dorsal and abdominal fins.
Originality. For the first time we carried out works on the study of the peculiarities of peled growth based on morphometric features in the conditions of their combined rearing in the Polissya and Prykarpattya zones. The obtained results will allow widening our knowledge on the topics of peled culture in pond farms in Ukraine.
Practical value. The obtained results showed the plasticity of peled in the conditions of their combined rearing in the Polissya and Prykarpattya zones of Ukraine that will contribute to the creation of local brood stocks of peled.
Keywords: peled, young-of-the-year, yearlings, morphometric features, morphologic features.
Purpose. To assess the developmental stability and cytogenetic homeostasis of fish populations in the Sluch River in the watercourse areas subjected to anthropogenic stress of different intensities.
Methodology. Studies of fish populations in the Sluch River were carried out within Berezne district of Rivne region. The condition of individual fish in the populations were evaluated integrally using morphological (evaluation of the stability of development based on the level of fluctuating asymmetry (FA)) and cytogenetic (micronucleus (MN) test of peripheral blood erythrocytes of fish) methods. The methods used allowed identifying the destabilization level of organism development, even in the cases when there is no direct disturbance of population homeostasis.
Findings. The found FA levels reflect minor (initial) deviations from the normal developmental processes of fish populations in in the studied watercourse areas. Especially significantly this is reflected in a high proportion of individuals with FA in the samples of roach, bleak, bream and perch. An excess in the frequency of MN erythrocyte cells in roach and pike blood relatively the level of spontaneous mutagenesis was observed in the cross section #2, which is exposed to sewage waters. The observed manifestation of degenerative processes in fish organisms at this stage can be evaluated as an increased reactivity of sensitive species to the presence of mutagenic agents in the composition of river pollution. The functioning of spawning populations gives reason to believe that the current level of human impact is not critical for the hydroecosystem.
Originality. For the first time we obtained data on the stability of development and cytogenetic homeostasis of fish populations in the hydroecosystem of Rivne region in current conditions of anthropogenic stress.
Practical value. The obtained results can be used for assessment and prognoses of wild fish stocks of the investigated hydroecosystem and can be taken into account when planning water protection activities within the river basin.
Keywords: fish populations, fluctuating asymmetry, cytogenetic homeostasis, developmental stability.
Purpose: To determine the size composition of anglers’ catches in major fishing gears in the Kakhovka reservoir.
Methodology: The work is based on ichthyological material obtained from anglers’ catches and commercial catches in gill nets with mesh size 36–120 mm during 2011–2013 in the upper and middle parts of the Kakhovka reservoir. Data collection and processing have been carried out based on generally accepted methods. In total, 7775 fish from 455 day anglers’ catches as well as 18165 fish from commercial catches for 6435 net-days have been analyzed during the study period. Statistical data processing was carried out in MS Excel.
Findings: In the Kahovka reservoir, 76.96% in the anglers’ catches is by-catch of juvenile fish and this exceeds the respective value in commercial fisheries (5.97%). Catches from boats are characterized by the largest mean size of fish – 19.27 cm as well as the maximum body length – 74 cm, however, the by-catch of juvenile fish is the highest among the examined angling techniques – 77.26%. The largest amounts of juvenile fish are caught during winter period. Among popular hook and line gears, leger rigs catch the lowest percentage of juvenile by-catch (58.61%) compared to float fishing (96.79%). The degree of the relationship between the fish caught and hook size is small and characterized by a correlation coefficient from 0.33 (for summer fishing) to 0.56 (for ice fishing).
Originality: A complex assessment of size characteristics of major targets of recreational fishing with the most common techniques and fishing gears has been carried out for the first time for a Ukrainian water body.
Practical value: It was found that the anglers’ catches consist mainly of fish, which did not reach the minimum legal sizes set by Fishing rules and allowed for angling. Measures for conservation of fish juveniles when practicing recreational fishing have been proposed.
Keywords: Kakhovka reservoir, recreational fishing, commercial fishing, fishing gears, catch size structure.
Purpose. To study fish culture parameters of young-of-the-year carp in the conditions of industrial fish-growing ponds when applying experimental repeated fertilization with distiller’s grain.
Methodology. The study was conducted in industrial fish-growing ponds. The wastes of alcohol industry – the distiller’s grain as organic fertilizer was gradually introduced into ponds at following amounts: first application – 1,0 t/ha, second application in 10 days – 0,5 t/ha, third application in 12 days – 0,5 t/ha. The control ponds were fertilized with humus (2 t/ha). Young-of-the-year carp were grown in monoculture at stocking density of 30 000 fish/ha. In addition, 100 kg/ha of lime were applied during the culture season in the experiment and control. Fertilization with humus and application of lime in ponds, hydrochemical studies, sampling and processing of hydrobiological samples, fish culturing and statistical studies were carried out according to standard methods.
Findings. Gradual fertilizing with distiller’s grain (to the total 2 t/ha) gave the possibility to create favorable hydrochemical and hydrobiological regimes. An average daily growth in the experimental fish groups of 0,44 ± 0,09 g/day that was similar to in the control (0,45 ± 0,11 g/day) with positive significant correlation between them (r = 0,97; p <0,001) was achieved. The performed measures gave a possibility to obtain fish productivity in the experimental variant 10.7% more than in the control. An economic effect of 14.3% cost reduction for fertilizing ponds was achieved.
Originality. For the first time we presented the results of fish culture and biological parameters of young-of-the-year carp in industrial ponds when applying 3-time fertilization with distiller’s grain.
Practical Value. The obtained results are the basis for the broad use of non-traditional organic fertilizer – distiller’s grain in industrial ponds, when growing young-of-the-year carp in monoculture.
Keywords: carp, young-of-the-years, distiller’s grain, natural food base, fish-growing ponds, fish productivity.
Purpose. To conduct the approbation of the previously developed dehydration-vitrification method on the sperm of brown trout with a rough estimate of component stages and process steps in the cryopreservation of the biological object: temperature adaptation, cryoprotector selection, of freezing-thawing mode, and cryopreservation method in general.
Methodology. We developed and worked out the dehydration-vitrification method for freezing sperm of different fish species. Data collection and processing were performed by standard fish breeding techniques. Preparing and dilution of sperm by cryoprotective medium were carried out according to approved instructions.
Findigs. We examined the possibility of brown trout sperm cryopreservation with the aid of the developed dehydration-vitrification method. The following conditions for cryopreservation of the biological object were determined: media and cryoprotectors, freezing-thawing modes. The effect of the technological steps of sperm cryopreservation process in brown trout on the reduction in preservation (S) and efficiency (W) was analyzed. The preservation of thawed sexual cells in brown trout with 90% initial activity of native sperm was 25%. The total efficiency of cryopreservation process was 28%. Duration of thawed sperm storage with its capacity for active translational movement after activation in water in different samples was about 15–30 seconds. It was noticed that the cause of decline in the efficiency of the cryopreservation process are complex factors such as various pH values, osmotic pressure of water and ejaculate dilution medium. These factors determine individual characteristics of biological objects and cryoprotective medium composition.
Originality. The previously developed dehydration-vitrification method allowed obtaining the reliable result for sperm cryopreservation in browm trout for the first time.
Practical value. The study showed the positive effect of applying the developed method and selected modes of sperm cryopreservation in brown trout.
Keywords: сryopreservation, brown trout, sperm, survival.
Purpose. To determine the effect of temperature regime fluctuations on the development of silver carp embryos, as well as the activity of enzymatic reactions in fish eggs.
Methodology. The studies were conducted at the experimental station of the Institute of Hydrobiology of Bila Tserkov, Ukrainian National Academy of Sciences, from June to July. The biological materials were silver carp eggs, embryos and larvae. The dissolved oxygen content was determined using the Winkler method at four o’clock in the morning. Alkalinity phosphatase and LDG activity were determined using a set of reagents «Alkalinity phosphatase» and «LDG» (Phyllis diagnosis, Ukraine). SDH activity was determined by Vexy. The activity of Na, K-Mg-dependent-activated ATPase was determined as growth of inorganic phosphorus in the incubation medium by Kindratova M.N. et al. Protease activity was determined using immune enzymatic method of Tyurina et al. The obtained results were processed statistically in Statistica 5.5, Epaprobit analysis was used for calculating LC/EC values (Version 1.5).
Findings The results showed that a delay of embryonic stages of development occur, the number of abnormal embryos increases, and the reproduction efficiency of fish reduces with an increase in water temperature and decrease in the dissolved oxygen content in water. The temperature factor had a significant effect on the activity of key enzymes, in particular the energetic metabolism changed from aerobic to anaerobic.
Originality. It was found a negative effect of abiotic factors of water medium and drastic fluctuations in water temperature and gas regime of water bodies on the course of embryogenesis of silver carp that is especially important in the conditions of climate change.
Practical value. The obtained results showed that the level of optimum and unfavorable environmental factors during the change of embryonic stages in embryonic and larval fish can be established based on the activity of lactate dehydrogenase, succinate dehydrogenase, ATPase and protease.
Keywords: embryonic development, silver carp, fluctuations of temperature regime in water bodies, enzymatic activity.
Purpose. To study some morphometric parameters, protein and lysozyme content in organs and serum in several sturgeon species reared in aquiculture at the ages of 3, 8 and 18 months, and to investigate the specific and age distribution of lysozyme in fish organs.
Methodology. For the experiments we used sturgeon species of different age groups reared in the fish farm «Fortuna XXI» located in the Galerny Gulf of the Dnepr river. The study objects were: bester (Huso huso×Acipenser ruthenus), age of 3, 8 and 18 months; Russian sturgeon (Acipenser gueldenstaedtii), age of 3 months, Siberian sturgeon (A. baeri) and sterlet (A. ruthenus), age of 8 month. Following morphometric parameters were determined in the studied fish: weight (g), length (cm), absolute weight of liver, kidneys, spleen (mg), condition factor and relative weight (index, ‰) of organs. The lysozyme content was determined in serum and extracts of the tissues of fish organs by a diffusion method on the agar and protein content was determined by Louri's method.
Findings. We detected significant differences in morphometric parameters, protein and lysozyme content in organs and serum of 3-month bester and Russian sturgeon as well as specific differences of relative organ weight, protein and lysozyme levels in organs and serum of 8-month Siberian sturgeon, bester and sterlet. A comparison of the investigated parameters in 3, 8 and 18-month bester showed an increase in the condition factor with fish growth, significant changes of protein content in fish of different age groups, high level of lysozyme in kidneys and serum of 18-month fish, redistribution of lysozyme contents in fish organs depending on age.
Originality. First comparison of several morphophysiological parameters of 3, 8, 18-month sturgeon species (sterlet, Russian sturgeon, Siberian sturgeon, bester) reared in aquiculture.
Practical value. Taking into account the high commercial value of sturgeon species, the conducted studies showed that in the conditions of cage culture with the use of live and high quality granulated feeds, juveniles and age 2 commodity sturgeons maintain the high level of general nonspecific immunity inherent to sturgeon species living in natural conditions.
Keywords: sturgeons, fish age, morphometric parameters, protein, lysozyme, aquaculture.