Purpose: analysis of the species diversity and quantitative composition of fish eggs and larvae, as well as the features of the spatial distribution of the most abundant representatives of spring ichthyoplankton in Kronotsky Bay.

Methods: standard methodology for conducting ichthyoplankton surveys with subsequent office processing of the material.

Novelty: new information on the species composition and spatial distribution of the most frequently occurring species in the ichthyoplankton of Kronotsky Bay is presented for the period 2004-2022.

Result: the eggs and larvae of 36 fish species were recorded in ichthyoplankton samples. The dominant components were the eggs of the pollock Gadus chalcogrammus and the lemon sole Pleuronectes quadrituberculatus, as well as the larvae of the sculpines of the genus Gymnocanthus. Their spatial distribution is shown depending on the classification of years («warm», «cold», and «normal»).

Practical significance: information on the spatial distribution of commercial fish species during the early ontogenesis period will improve the reliability of forecasting their stocks.

The objective of this study was to conduct regional genetic identification of juvenile chum salmon (Oncorhynchus keta) within mixed aggregations in the Okhotsk Sea based on materials from the autumn trawl survey of 2021, in order to estimate stock abundance and forecast returns of the 2020 year-class.

The research methods included analysis of polymorphism at eight microsatellite loci (Ssa20.19, One101, Oke3, Oki1b, Oki23, Ogo2G, Oke11, Ots102), as well as statistical analysis and genetic identification using a reference database of allele frequencies for chum salmon populations from the Okhotsk Sea basin and the software packages Cervus, GDA, ONCOR, and GenClass2.

The results of genetic identification made it possible to determine the proportions of juvenile chum salmon originating from the main spawning regions of the Okhotsk Sea basin, with a predominance of individuals from Sakhalin Island (31 %), followed by the Amur River basin (27 %), Iturup Island (22 %), and Western Kamchatka together with the northern mainland coast of the Okhotsk Sea (19 %). Based on the identification results, the expected number of returning adult chum salmon from the 2020 year-class of Western Kamchatka origin was estimated. These estimates correspond to the already observed returns of age group 3+ and the preliminary evaluations for group 4+. This indicates a positive consistency between genetically derived estimates and the actual data at the current stage of research, while final conclusions regarding the reliability of the approach will require accumulation of multi-year observations.

The practical significance of the study lies in improving the accuracy of chum salmon stock monitoring and refining the predictive assessments of spawning returns, thereby contributing to the development of more scientifically grounded recommendations for the sustainable management of salmon resources in the Far Eastern fisheries basin.

The goal of this study is to assess a method for identifying salmon of the genus. Oncorhynchus using microsatellite markers developed by a team led by L. A. Zhivotovsky. This method was applied to fish products intended for commercial sale.

Materials and Methods: The study utilized samples of processed salmon products available at retail outlets on Sakhalin Island. To verify microsatellite analysis, the species identity of the samples was confirmed using DNA barcoding.

Novelty: The studies conducted have shown that the method is effective in determining the species origin of various salmon products, including salted, smoked, dried, highly processed items (such as canned salmon) and caviar. Additionally, this method can identify the species composition of unstructured mixtures, such as minced meat and its semi-finished products.                                                               

Results: we successfully identified the species of all commercially produced Pacific salmon products analyzed in this study, including highly processed items and mixed minced meat from multiple fish species. However, we encountered difficulties with mislabeled rainbow trout products. We found several cases where the fish products did not match the species indicated by the sellers. This discrepancy was most notable among the valuable Pacific salmon species: sockeye salmon, masu salmon, coho salmon, and chinook salmon. It is important to highlight that all the chinook salmon products tested were found to be rainbow trout, and the triploidy detected in these samples suggests their origin is from aquaculture.

Practical significance: unlike the commonly used DNA barcoding method, microsatellite analysis can be applied to a wide range of products from Pacific salmon of the genus Oncorhynchus. This approach is particularly advantageous because it can detect samples with highly fragmented DNA as well as mixtures of DNA from different species. Therefore, microsatellite analysis shows promise for use in genetic laboratories that are analyzing fish products.

The aim of the work: to clarify the distribution and status of endemic kelp stocks in the coastal areas of the Kuril Islands.

Methods used: the analysis was based on literature sources and information obtained in 2019 according to the recommended methods of fishery research.

Novelty: An array of data on the distribution of endemic species was analyzed, the current state of rare species resources was determined, and recommendations for the exploitation of kelp algae of the Kuril Islands were developed.

Result: Of the five endemic kelp algae of the Kuril Islands, only one, Saccharina fibrosa, forms a significant reserve in the coastal area of Iturup Island. Potentially commercial species of laminarian algae include species with limited distribution and endemics of the Hokkaido–South Kuril region: S. kurilensis, S. angustata, Arthrothamnus kurilensis. Their total reserve near the southern Kuril Islands reaches 470 thousand tons. The coastal zone of the middle Kuril Islands is characterized by the greatest species diversity of kelp algae, which confirms the presence of a center of morphogenesis in this area. The total stock of laminarian algae in the coastal zone of the southern Kuril Islands exceeds 1,381 thousand tons. The least productive should be considered the coastal zone of the northern Kuril Islands, the stock of laminarian algae amounts to only 257.9 thousand tons. The productivity of the middle Kuril Islands reaches 1,795 thousand tons.

Practical significance: developed recommendations for the rational use of resources of the laminarian algae of the Kuril Islands.

Purpose of the study: determination of the area of applicability of commercial return coefficients in fisheries research using the example of whitefish of the Ob basin.

Research methods: The calculated values of the coefficients for the period 1970-2015, as well as materials on artificial reproduction for 1986-2011, were used for the analysis. The number of fish was calculated using the restored stock method. The coefficients were checked according to the following criteria: the survival rate of juveniles; the return of producers from the number of larvae; the number of descendants of a pair of producers reaching puberty.

Results: The analysis of various indicators confirmed the validity of replacing the previously valid coefficients with new ones. The relationship of coefficients with survival and the level of reserve utilization is shown. It is noted that this relationship is contained in the equation of the coefficient. Various aspects of the application of coefficients are considered. Special attention is paid to the analysis of changes in the intensity of fishing and natural reproduction, as well as the determination of the volume of IUU fishing. An increase in the level of use of generation by fishing has been established with a decrease in its number.

Practical significance: The previously unused possibilities of using coefficients to determine the effectiveness of artificial reproduction, determine the volume of IUU fishing, predict the yield of generations and regulate fishing are disclosed.

Objective: to verify the principles of best aquaculture practices in cage fish farming to identify constraints to sustainable development and develop ways to reduce their effects

Methods: comparative-a nalytical methods are used. The information basis for analysis was compiled from the responses of farmers to a questionnaire developed in accordance with principles of the best practices.

Novelty: the assessment showed a high degree of compliance of various aspects of cage farming activities with the principles of the best aquaculture practices/

Results: The highest degree of compliance is established for areas that are strictly regulated, and this is facilitated by the control of executive and regulatory authorities. A slightly lower degree of compliance was identified in the groups of criteria related to the fish health and the farm management, which have less strict regulation, but reflect the responsibility of farmers for the safety and productivity of fish, the efficient work of personnel and the economic results of their activities. Areas of activity in the field of reducing environmental impact and interaction with the scientific and educational community were least consistent with the principles of the best aquaculture practices. This may be due to insufficiently developed regulatory framework and due to underestimation by farmers of the importance of these fields for the future. Despite the wide coverage of farms in the survey, relatively few farms responded to the questionnaires, and they also showed a high degree of compliance with the principles of best practices. Most farmers who did not respond to the questionnaire probably have certain difficulties in various fields of their work, which do not allow them to work effectively, to develop sustainably and openly answer the survey questions.

Practical significance: This study is a step in the development of a set of guidelines for the best practices of aquaculture in Russia. The widespread use of this set of rules by farmers can be considered as a methodological basis for the sustainable development of aquaculture in our country.

Aim: To evaluate the effects of 17α-methyltestosterone treatments on growth performance, morphological and biochemical blood parameters, condition of internal organs, and sex reversal in juvenile rainbow trout.

Methods: Experiments were conducted on larvae and juveniles that received feed supplemented with 17α-methyltestosterone for 3, 4, and 8 weeks after the onset of exogenous feeding. The influence of the hormone was assessed based on hematological and biochemical blood indicators, as well as histological examinations of internal organs.

Novelty: A comprehensive assessment of the long-term consequences of hormonal sex reversal in rainbow trout was performed 15 months after 17α-methyltestosterone application. The study revealed that treatment duration significantly affected hematological and biochemical blood parameters, while no adverse effect on internal organs was detected, except for the reproductive system.

Results: The inclusion of the hormone in feed for 4 weeks resulted in up to 90 % males. Extending the treatment to 8 weeks led to the formation of up to 90 % sterile individuals. Long-term effects were manifested as a minor nonlinear decrease in hemoglobin, hematocrit, and erythrocyte counts, accompanied by an increase in leukocyte and platelet proportions. Significant reductions in albumin, total protein, and creatinine concentrations were recorded, along with slight decreases in AST activity, blood urea nitrogen, and triglycerides. However, all variations remained within reference ranges. Histological examination of the liver, intestine, heart, and spleen of trout aged 5 and 15 months demonstrated normal ontogenetic changes without pronounced structural alterations attributable to the treatment.

Practical significance: The study confirmed that early-life administration of 17α-methyltestosterone does not negatively affect the functional state of juvenile organs and is an effective approach for producing up to 90 % males when applied for a 4-week feeding period.

Goal: To verify a low-pass sequencing method (lpWGS) with subsequent genotype imputation in rainbow trout.

Materials and Methods: DNA extraction was performed by a customized protocol in plate format (4 × 96 samples), sample preparation and sequencing were performed using the MGI AgriHigh Low-pass WGS Package, reference database creation, and imputation were performed using the VNIRO Bioinformatics Group computing cluster.

Novelty: low-pass sequencing was conducted on rainbow trout for genomic selection purposes for the first time in Russia.

Result: Analysis of 260 rainbow trout individuals using this method demonstrated high genotyping reliability; on average, approximately 90 % of the 12 million loci in the genomic marker panel were reliably identified for each fish. High genetic differentiation was demonstrated among the four studied rainbow trout breeding lines.

Practical significance: The verified low-pass sequencing genotyping method can be used as a cheaper and more informative alternative to traditional DNA microarrays. This method enables both GWAS analysis and breeding value estimation for forming a trout breeding nucleus at the genomic selection Center.

The goal of the study is to develop a method for knocking out the common carp two paralogous copies of the myostatin gene using the CRISPR/Cas9 system with delivery of the editing complex into zygote by microinjection.

Materials and Methods: fertilization of common carp eggs was carried out in vitro, sgRNA was synthesized by PCR with overlapping oligonucleotides and subsequent transcription, the editing complex consisting of sgRNA and the Cas9 endonuclease was delivered to the carp zygote by microinjection before the first cleavage. The region contained the editing site was amplified by nested PCR, editing events were detected by Sanger sequencing and confirmed by NGS.

Novelty: For the first time in Russia, a knockout system for the common carp myostatin gene has been developed, allowing both paralogous copies of the gene to be modified simultaneously.

Result: 12 F0 common carp individuals with knockout of the myostatin gene were obtained.

Practical significance: A methodological approach has been tested that allows for the rapid and controlled production of common carp with programmed mutations. Myostatin gene-deficient fish exhibit increased muscle growth due to hypertrophy and hyperplasia of muscle fibers, resulting in improved fish fillet quality. Fast-growing fish populations are more suitable for aquaculture than populations with standard growth rates.

The aim of this work is to analyze the long-term changes of atmospheric circulation parameters over the Black Sea in 2000-2021 and compare them with the long-term dynamics of the anchovy stock in the Sea of Azov and the catch of Black Sea anchovy off the coast of Crimea.

Materials and methods: the data of August surveys of anchovy in the Sea of Azov, fishery statistics on the catch of Black Sea anchovy, data of Copernicus Marine Service information system on satellite altimetry in the north-e astern part of the sea in April and near the western shores of the Crimean Peninsula in November, indices of regional atmospheric circulation, graphical and statistical methods of analyzing these data were used in the work.

Scientific novelty: the element of novelty in the work is the use of annual and long-term variability of atmospheric circulation indices in the study of anchovy migration in the Black Sea.

Result: it is shown that in the north-e astern part of the Black Sea in April the strengthening of eastern atmospheric transports favorably influences the formation of high summer stocks of anchovy in the Sea of Azov, and the strengthening of western transports in the north-w estern part of the sea in October promotes on the formation of high commercial winter stocks of Black Sea anchovy near the coast of Crimea. The reason for these changes in atmospheric circulation is the annual variability of vorticity of zonal atmospheric transports over the sea.

Practical significance: the obtained results can be used in predictive assessments of the Azov and Black Sea anchovy reserves in the waters of the Russian Federations with seasonal advancement.

Purpose: assessment of climatic factors influencing the dynamics of Amur pink salmon catch and determination of the mechanisms of this influence during periods of high and low salmon runs to the Amur estuary.

Research Material: salmon catch data from the Amur estuary, water temperature observations from the ESIMO electronic database, air temperature and precipitation data on coastal GMS were obtained from the archives of the VNIIGMI MDC and the archives of the Reanalysis (NCEP/NCAR Reanalysis Monthly Mean and Other Derived Variables) of atmospheric pressure P₀, geopotential H₅₀₀.

Methods used: to identify critical levels of salmon catches, an interval recognition algorithm was used, previously developed by a team of authors and demonstrated its effectiveness in solving fisheries problems.

Results: the possibility of determining in two years whether the conditions for the survival of pink salmon during the incubation period will be favorable or not, as well as a forecast for a year of favorable conditions for the survival of pink salmon based on an estimate of the water temperature during the slope, which depends on the characteristics of atmospheric circulation.

The purpose of the work: assessment of the quality indicators of roach (Rutilus rutilus caspicus) to determine its nutritional and biological value.

Methods used: analytical research methods in the field of ensuring the quality, nutritional and biological value of products from hydrobionts in international and Russian databases. Physical and chemical research was conducted using standard methods. Instrumental research methods, including mass spectrometry, gas chromatography, and others, were used to determine the biochemical parameters of Caspian roach products.

Novelty: modern biochemical indicators of Caspian roach products have been determined, which characterize their biological value and usefulness.

Practical significance: collecting up-to-date data on the quality of Caspian roach products is essential for assessing their nutritional and biological value, despite the moratorium on Caspian roach harvesting in the Volga- Caspian region to restore its stocks. The results of these studies will form the basis for subsequent monitoring of the physiological and biochemical state of Caspian roach and assessing the nutritional value of Caspian roach products.

The purpose of the work: based on the results of expeditionary research conducted by VNIRO in 2019, to demonstrate the perspectives of expanding aquatic biological resources harvesting in the seas of the Arctic Zone of the Russian Federation. Expanding harvesting in the seas surrounding the Russian Arctic regions would have a multiple effect: it would provide the population with vital fish protein products in high-latitude conditions and also stimulate development of related industries and sectors, such as logistics, storage, ship repair, and shipbuilding.

Materials and methods: to assess the bioresource potential of the seas washing the regions of the Arctic Zone of the Russian Federation, a method of complex fisheries research was used within the framework of the expedition.

Novelty: options for expanding domestic fisheries in the seas of the Arctic Zone of the Russian Federation, based on the analysis of data obtained from comprehensive expeditions, have not previously been considered. No studies or forecasts for the production of key commercial fish in the Arctic seas have been published in the scientific literature.

Practical significance: the results of scientific research conducted by VNIRO scientists during the expedition of the R/V «Professor Levanidov» in 2019 formed the basis for the scientific recommendations to start pollock fishery in the Chukchi Sea and snow crab in the Kara Sea in 2021. Conducting large-s cale and regular research in the seas of the Arctic Zone of the Russian Federation will provide more information on their bioresource potential, which, in turn, will provide fishing organizations with the scientific advice for increasing the volume of aquatic biological resources harvested.

The purpose of the expedition research is to assess the biological status of commercial species crab in the western part of the Bering Sea.

Materials and methods. The data was collected from the catch of traps during the monitoring of the crab fishery on 29.04.-19.06.2025 at depths of 50-379 m. The following species were studied: blue king crab (Paralithodes platypus), snow crab (Chionoecetes opilio) and tanner crab (C. bairdi), as well as other species found in by-catch. The formation of a database with parameters of the biological state of crabs and its processing were carried out according to standard methods adopted in VNIRO.

Results. Biostatistical information on functional groups is given for three mass crabs. In the western part of the Bering Sea, the biological parameters of P. platypus and C. bairdi correspond to the spring period, and their older size and age groups dominated the catches. Due to the paucity of data, the biological parameters of C. opilio in the study areas are insufficient for an adequate assessment. The red king crab (P. camtschaticus) has become common in the West Bering Sea zone, and dense aggregations of this species are present in the Karaginsk subzone. Data on the filling of limbs with muscle fibers and the total protein content in crab hemolymph between molts were collected for all species.

Practical significance. The crab fishery monitoring results will be taken into account in the preparation of forecast materials to establish the total allowable catches of P. platypus, C. bairdi and C. opilio in the West Bering Sea zone and in the Karaginsk subzone.

The aim: the assessment of the current biological state, qualitative and quantitative composition of the commercial catch and catch per effort of Siberian sturgeon in the lower reaches of the Lena River.

Material: data of the biological analysis of the catch of Siberian sturgeon during the specialized fishery of Nelma and Sturgeon using fixed and drift nets in the second and third ten-day periods of June 2025.

Results: The water level in the Lena River was above the long-term average. The catch per effort was: with set nets –  on average 0.4 specimen/day, with drift nets –  1 specimen/drifting. The size range of Sturgeon varied in total (zoological) length ab from 64.5 cm to 210.5 cm, –  on average 92.2 cm; in length ac (fork length) –  from 56.0 to 160.0 cm, –  on average 82.4 cm. The weight of individuals varied from 1.0 to 31.6 kg. 98 % of the catch corresponded to the commercial measure of 62 cm (fork length) established for this fishery basin. Females and males were equally distributed in the catch. Females are generally larger than males. Females at the III-IV and IV stages of gonad maturity constituted 2/3 of the catch. The size of sexually mature individuals indicates their repeated participation in spawning. This indicates a healthy sturgeon population in the Lena River. The Clarke body condition index (BCI) of Sturgeon averaged 0.46, ranging from 0.36 to 0.69.

Practical value: the research results are applicable to assessing the status of the Siberian sturgeon population in the Lena River, as well as adjusting the total allowable catch of this species.