The article considers the system of management transformation in the fisheries complex of the Russian Federation from administrative and command management in the conditions of the USSR to the present day and reveals their cardinal difference. Firstly, there are no powers of the current management structure – the Federal Agency of Rosrybolovstvo in such activities as manufacturing, transportation, storage and trade, that is, the logistics chain «production – counter» is artificially broken. Secondly, industrial relations in these areas are regulated by different departments. It is proposed in the current conditions in the management system to introduce the functions of the chief coordinator of various departments on issues of the fisheries complex and assign them to the Federal Agency Rosrybolovstvo. The creation of a comprehensive system of coordination of all interested departments, responsibility and regulation of relations to achieve final results at the federal level will not require large costs, and the positive result is obvious. The authors propose, taking into account the ongoing transformation in the Russian fisheries complex, the formation of a new organizational and managerial structure – an industrial economic ecosystem, which is a kind of complex that is characterized by self-organization, self-regulation and self-development under the influence of various external factors and the environment. The lack of necessary and reliable information can become a brake on the development of digitalization of the fisheries complex. Currently, VNIRO is dynamically developing a digital information and analytical platform. Giving the platform the status of a project office in the future will make it possible to cover the entire array of necessary information and areas of analysis under the auspices of the Federal Agency Rosrybolovstvo in a unified manner with other interested management bodies, enterprises, unions, public organizations and regional authorities. The ecosystem is well synchronized with the modern digital economy, as a result of which the interaction of companies moves to a qualitatively new level, which will allow for more concentrated achievement of local at the enterprise level or strategic goals of Russia’s economic development. Thus, the introduction of new principles in the management system aimed at the final result affects the entire federal management structure of the fisheries complex.

In 2018–2019 the second Amur ichthyological expedition has been prepared and is being conducted since 2020. The impetus for its organization was a sharp drop in the catches of Pacific salmons in the basin of the Amur River in 2017 and 2018, when after the maximum catch in 2016 (65,2 thousand tons), their catch decreased to 26,9 and 21,6 thousand tons, respectively. This required the adoption of urgent management decisions to preserve their reserves, as well as the expansion of the study of the Amur aquatic biological resources. The expedition has a complex character; the research covers the channel and accessory system of the middle and lower Amur, as well as Khanka Lake. Totally completed: about 5 thousand stations, more than 1,1 thousand hydrobiological samples were taken, about 40 thousand fish were subjected to bioanalysis. New data on the biology of Pacific salmon, smelts, freshwater and sturgeon fish species have been obtained and partially published (70 papers). A number of modern innovative research methods have also been introduced (the use of UAVs and GIS systems to account for Pacific salmon spawners, microchemical analysis of otoliths to assess the effectiveness of their artificial reproduction). The results obtained are of wide practical importance: they are used in the development of measures to regulate the fishing of various aquatic biological resources, including when amending the Fishing Rules.

Based on research findings from 1963–2021 the analysis of size-age indicators, qualitative structure of populations and changes in the number of kaluga Huso dauricus and Amur sturgeon Acipenser schrenckii in the river was carried out. Amur. It is established that in the period from the 60s. last century to 2008–2011 in the kaluga and the Amur sturgeon in the Amur River, there was a reduction in the size range and number of age groups, the proportion of mature individuals, the level of replenishment of populations with juveniles and abundance. The main reason for these changes is INN fishing (illegal, unreported and unregulated). According to the results of research in 2021, it was revealed that the modern number of kaluga exceeded the figures of the 60s. last century. In the Amur sturgeon, the process of population growth has not yet reached the historical values noted in the 1960s–1970s, but exceeded the indicators of the 1980s and subsequent years. Despite the noted positive points, at present, the population of kaluga in the river. Amur is characterized by the smallest average size and age over 60 years of study. The situation is better for the Amur sturgeon, which is due to the lower interest of fishermen in this species and the large volume of release of its juveniles from sturgeon hatcheries (ORZ). The reason for the positive dynamics is the artificial reproduction that has been developing on the Amur over the past decade, as well as the introduced set of restrictions on the Pacific salmon fishery. To further increase the number of Kaluga and Amur sturgeon in the river. Amur, it is proposed to maintain the current volumes of artificial reproduction of sturgeons and extend the restrictive measures in the salmon fishery for at least the next 10 years.

The dependence of the number of progeny of the Amur fall chum salmon Oncorhynchys keta on the number of parents was analyzed. It is shown that the deviations of the actual number of offspring from the theoretical ones, calculated by the Ricker equation, depend on the belonging of the fish to a particular generation. An equation is proposed that describes the dependence of the number of progeny of the autumn chum salmon on the number of parents and reproduction conditions. The problem of the variability of the optimal number of parents due to the change in reproduction levels is discussed.

For the first time, the «tumbleweeds» – consortia of the Amur estuary were studied. The determinants of consortia are fragments of brown algae-macrophytes thalli and colonies of hydroid polyps, rolled up into a ball by currents, and the consorts are amphipods inhabiting it. It was show that the reason for the emergence of consortative relationships is the hydrological conditions of the estuary and features of it bottom landscape, under which amphipods are forced to seek shelter. In the diet of the kaluga Huso dauricus and Amur sturgeon Acipenser schrenckii in the Amur Estuary, amphipods were found together with plant remains, which indicates the feeding of sturgeons by consortia. Kaluga, in comparison with the Amur sturgeon, consumes such type food much more often and in greater quantities. Animals associated with the aggregation of dead algae and polyps play a significant role in the formation of the food base for sturgeons in the Amur Estuary.

Structure, quantitative indicators, distribution features and main communities of macrozoobenthos of Sakhalin Bay (the Sea of Okhotsk) are described. Mollusks (mainly bivalves), crustaceans and sea urchins determined the total macrozoobenthos biomass. The main regularities of the macrozoobenthos distribution in the bay are given. Two zones are distinguished by hydrological characteristics, distribution of the composition and quantitative characteristics of macrozoobenthos, benthic communities, and according to the data of ordination analysis: the zone of localization of the runoff lens of the Amur River with a water salinity of less than 26 psu and the zone of distribution of typical marine waters. 9 benthic communities are described: the »estuarine-lagoonal» communities of Archaeomysis grebnitzkii + Haustorioides magnus + Potamocorbula amurensis, Potamocorbula amurensis, Macoma balthica + Cyrtodaria kurriana, Siliqua alta, the typically »marine» communities of Nephtys caeca, Serripes groenlandicus, Balanus crenatus and the communities of transitional type Saduria entomon and Echinarachnius parma, which are found in both hydrological zones. Predominantly filter feeders, with a significant role of detritus feeders and detritus feeders – filter feeders, form the trophic structure of macrozoobenthos. Trophic communities dominated by filter feeders - detritus feeders and detritus feeders are represented in the coastal area of the western part of the water area, the group of filter-feeders is localized seaward. Trophic communities with a predominance of filter feeders - detritus feeders and detritus feeders are represented in the entire depth range of the eastern part of the water area. Water salinity, soil type and depth are the main factors affecting the distribution and abundance of macrozoobenthos.

Comprehensive studies of aquatic biota were carried out in the 30s and 40s years of the 20th century. In this regard, it was necessary to collect updated data on different groups of aquatic animals. The purpose of this work was to conduct research on the collection of zoobenthos in the area from the Amur Estuary to the city of Blagoveshchensk. The work was carried out in 2018–2020 years using a GR-91 rod grab, a Levanidov bentometer (0,4×0,4 m), and a shellfish collection frame (0,5×0,5 m). According to our observations and literature data, the distribution of benthic animals in the channel part of the Amur and floodplain lakes is greatly influenced by the level regime of the water body. The highest values of biomass in collections were given by mollusks due to their large size. Insect larvae and oligochaetes had a high abundance but low biomass due to their small size. During the work, most of the samples turned out to be empty, which is associated with periodic rises and falls in the water level. The maximum values of biomass from 0,5 to 1,0 kg/m2 were noted in areas of mollusk concentrations, mainly Nodularia douglasiae. In other places, quantitative indicators were several orders of magnitude lower, from several mg to several g/m2.

Since 2022, the possibility of trawl fishing on Khanka Lake has been opened. In 2018 and 2020, accounting work was carried out using a beam trawl. Studies have shown that the highest biomass in trawl catches was far eastern freshwater shrimp (Palaemon modestus), noodle fish, sharpbelly, bagrid catfish and humpback. According to the trawl survey, the stocks of shrimp and small fish species amounted to 3,5–4,6 thousand tons. Taking into account the underestimation of these biological resources during the performance of work, the resource base can be at the level of 14,0–15,0 thousand tons.

Data on spawning migrations, biology and abundance of the spawning group of the pacific rainbow smelt Osmerus dentex of the Amur River in the period from 2014 to 2021 are presented. According to the data of mass labeling of producers, the smelt extracted in the Amur estuary and the Amur riverbed belongs to one unit of stock, the migration routes of producers and the spawning rate have been clarified, and a decrease in the number of spawning herds has been recorded. Analysis of the main biological indicators revealed a significantly significant (p<0.001) decrease in size and mass characteristics, a change in age structure, and a tendency to increase the proportion of females in the spawning herd. The analysis of fertility dynamics revealed a decrease in the indicators of individual and relative fertility of fish of the spawning herd in 2017 (p<0,001), however, in general, the observed changes fit into the range of average long-term fluctuations.

The feeding spectrum of the Amur pike Esox reichertii Dybowski, 1869 in the reservoirs of the middle and lower reaches of the Amur River was determined. The absence of significant differences in the nutrition of pike of different sexes is shown. The nutrition of pike of different size groups is considered, the comparison of the size and weight indicators of food objects in adjacent size groups of the predator is carried out. The selectivity of pike feeding was assessed. The values of ENG in different size groups of the predator are determined. The nutrition of pike in various areas, conditionally divided into biotopes, is considered. The comparison of pike feeding in winter and summer is carried out.

This paper informs about characteristic of linear and weight growth of Amur silver crucian carp on the basis of the L. von Bertalanffy and I. I. Schmalhausen’s growth equations. For this description, the material collected in the period from 1997 to 2022 on the territory of two districts of the Amur River – in the watercourses of the Sredneamurskaya floodplain system and in the lower part of the Lower Amur was used. The main characteristics of the growth of the silver crucian carp is sexual dimorphism and compensatory growth. The maximum observed body length (Ad) of the Amur River silver crucian carp is 40 cm, body weight 2,1 kg. Differences were found in the indicators of linear, weight growth and growth rate of silver crucian carp living in the watercourses of the Middle Amur Lowland and in the lower part of the Lower Amur. Based on the coefficients of the growth equations, the coefficients of natural mortality for each year of life of females and males of silver crucian carp are calculated. The age of sexual maturity of females is 6 years. The commercial length of female silver crucian carp of the Middle Amur lowland, consistent with the age of mass maturation and the maximum biomass of generations should be equal to 20 cm, in the lower part of the Lower Amur – 23 cm.

Studies of the species composition and relative biomass of freshwater commercial fish of the Amur River in different districts of Khabarovsk Krai, Jewish Autonomous Region, and Amur Oblast in the period from 2018 to 2020 were conducted. A comparative analysis of research net catches for the period 2018–2020 with research net catches for the period 2000–2017 is provided. An assessment of fishing pressure in different fishing areas over the past 10 years is given. There has been a significant decrease in the biomass of the commercial stock in areas with high fishing pressure. It presents promising targets for freshwater fish species that, for various reasons, are not used by the fishery today.

Yellowcheck Elopichthys bambusa (Richardson, 1845) is a valuable commercial species. In 2020, after more than twenty years of a ban on fishing, the yellowcheck removed from the list of fish in the Red Book of Russia. Based on the data of scientific research surveys by nets (2437 catches) of 2010–2021, an increase in its number in recent years in the Russian part of the Amur River basin, compared with the end of the XX century, is shown. This is confirmed by the expansion of the species’ range both up and down the Amur, as well as by the occurrence of yellowcheck migrants in the coastal waters of northwestern Sakhalin. At the same time, in absolute terms, the number of this predator is small. In order to solve the issue of introducing yellowcheck into the fishery, it is necessary to conduct studies to research many aspects of its biology, and, above all, growth, age structure, age of mass maturation, as well as to research the influence of Chinese fishing the current state of its biological resources. The obtained preliminary estimates of the commercial stock’s biomass of yellowcheck (9,2 tons) and its minimal possible catch (1,7 tons) allows starting these works.

The results of a comparative analysis of the number of myotomes and fin rays in the dorsal and anal fins of Amur fall chum salmon fry of artificial and natural origin are presented. Juveniles of natural origin were distinguished by large values of the analyzed morphological features. The results can be used for the determination of juvenile chum salmon of natural and artificial origin at the intra-basin level for large tributaries of the Amur River.

Materials are presented on the study of the technology of harvesting Pacific salmon, using fixed seines of the «zaezdok» type in the Amur estuary and the river. Amur, in order to ensure the passage of spawners of Pacific salmon during passing days without dismantling the wings and the trap, but only by closing the inlet device of the reservoir. The results of the conducted studies showed that the design of a fixed seine of the «zaezdok» type does not prevent the passage of fish to spawning grounds, does not allow it to be bound and does not cause damage to the prey object. During periods of skipping spawners («passing days»), it is sufficient to close the entrance to the seine trap and raise its netting. This ensures the unhindered exit of fish from the fishing area of the prey tool. Installation of additional structural elements (windows, etc.) is not required to ensure the passage of fish.