Modern planktology is the science, which is comprehensively assessing the biological diversity, structure, and functioning of pelagic communities in various water bodies, as well as their roles in ensuring fish productivity and supporting the sustainable development of aquatic ecosystems. A detailed analysis of topical planktology issues at the current scientific level, identifying the most complex challenges, and assessing the prospects for the development of this science are essential not only for the successful fundamental research in aquatic ecology but also for addressing critical issues in fisheries and applied hydrobiology, environmental protection, and maintaining the health of aquatic ecosystems. In this regard, in September 2025, Russian planktologists and their colleagues from the Republic of Belarus gathered for the fifth time on the Baltic coast to participate in the scientific conference “Current Issues in Planktology”. The conference presented the latest advances in the studies of biodiversity and trophic interactions in plankton, taxonomy and identification of major groups of planktonic organisms, research results on invasive species and their roles in pelagic communities, and new information on harmful phytoplankton blooms in marine, brackish, and freshwater ecosystems. Furthermore, a taxonomic training course for young scientists was held during the conference.

A brief forecast of the status of the main commercial resources of the Barents Sea in 20302035 is presented, along with the availability of key production assets for fishing and crab extraction.

This article examines cluster policy as a systemic tool for enhancing the competitiveness of the fisheries sector (FSS) through technological independence, structural cooperation, and export orientation. The theoretical foundations of clustering and the requirements for a fisheries cluster are analyzed. The definition of cluster policy in the fisheries sector is clarified. The benefits of import substitution through localization of production and service chains, reduced dependence on imported components, logistics optimization, and the unification of quality standards (HACCP/ISO 22000) with the implementation of digital inventory planning and control platforms are analyzed.

Based on the materials collected in May-July 2025, the main biological indicators of the yellowfin sole (Limanda aspera) in the coastal waters of the northern and northwestern parts of the North Okhotsk Sea subzone are considered. A brief description of the size-weight indicators and sex ratio is provided. The data on the intensity of flounder fishing by amateur fishing gear in this water area is presented.

This article presents the data of Greenland halibut population catch and stock dynamics in the Norwegian-Barents Sea. It is noted that unregulated halibut fishing in the 1970s led to record catches and then depletion of this species. Since 1978, the Joint Russian-Norwegian Fisheries Commission (JRNFC) has been controlled transboundary species of the Barents Sea. Due to the regulation of fisheries, halibut stocks have gradually recovered. In the last decade there was set TAC at the rage of 25,000-27,000 tons, although recently biomass of the stock has again decreased. That’s why it was recommended to reduction of fishing pressure. There is considerable uncertainty in the stock assessment of halibut, including of inconsistencies in the reading techniques of recording structures. The article shows possibility of using Russian methods in Greenland halibut stock assessment.

Since 2009, the harp seal (HS) trade in Russia has ceased; however, pup production in the White Sea population remains low. Published data on HS nutrition, the energy expenditure on reproduction, and the state of the food supply are reviewed to identify the causes of low pup production. It has been shown that GT females, like all representatives of the pinniped order, have high costs for offspring. To successfully reproduce, females must gain over 85% of their body weight. The high costs of HS reproduction place high demands on the provision of food resources for breeding females. A critical factor for HS females, ensuring successful pup production, is the abundant generations of spawning capelin. Intense food competition for capelin with abundant generations of Atlantic cod reduces the ability of HS females to successfully prepare for reproduction. It was also shown that the cessation of the GT fishery caused a change in the intrapopulation structure, population aging, and an increase in the proportion of K-strategists, which also reduces the population’s reproductive potential.

The hydrochemical parameters of natural seawater quality in the coastal waters of the Sea of Japan during the spring-summer period of 2024 were investigated. An assessment of the influence of the studied parameters on the commercial characteristics of the gray sea urchin Strongylocentrotus intermedius was carried out. In Dunai Bay, an exceedance of the maximum allowable concentration (MAC) for chloride ions was recorded, indicating probable pollution by wastewater. No exceedances of heavy metals in bottom sediments were detected. Individuals in Dunai Bay were noted to have a greater body weight and a significantly higher gonadosomatic index, indicating a significant influence of environmental conditions on reproductive function. The obtained data are necessary for the science-based management of the fishery and reproduction of this aquatic organism.

Based on ichthyological materials collected in 2022-2024 on the Samur coast of the Caspian Sea, the biological indicators of silver carp, red and perch are considered.

It is shown that in the years under consideration, the average indicators of length, mass, and age consistently decreased in silver carp and perch. In 2023, compared to 2022, these indicators increased for the red, but decreased in 2024, becoming lower than in 2022.

This study is dedicated to evaluating the effectiveness of artificial reproduction of sterlet (Acipenser ruthenus) and common carp (Cyprinus carpio) in the Upper Volga reservoirs: Ivan’kovskoye and Uglichskoye. Based on long-term data (2012–2024), an analysis of the dynamics of juvenile release, survival rates, and the formation of commercial stocks was conducted. The results revealed low effectiveness of the measures: despite substantial stocking volumes (up to 858 thousand sterlet and 703 thousand common carp specimens annually), individuals in catches were encountered sporadically. The projected commercial stocks by 2031 are estimated at 85.99 t for sterlet and 407.07 t for common carp; however, based on the results of previous releases, the actual stocks are forecast to be significantly lower. Key issues identified include: the lack of an economic analysis on the cost-effectiveness of releasing juveniles of different size/weight classes, low values of the exploitation rate/recapture rate, and a deficiency in long-term monitoring. It is proposed that specialized studies be conducted to develop science-based measures for enhancing the effectiveness of artificial reproduction activities.

An assessment of the hydrochemical parameters of the environment at the location of the operating fish farm was carried out using the absolute and relative content of dissolved oxygen, permanganate oxidizability, bichromate oxidizability, nitrites, ammonium nitrogen, and phosphate phosphorus using generally accepted chemical methods. Water sampling was carried out at three points in spring summer and autumn in 2023-2024. Based on the results of the conducted research, the hydrochemical parameters are estimated by season. It was determined that the flow velocity did not meet the requirements in the autumn period, the oxygen regime in the area under consideration was satisfactory, the total amount of organic substances exceeded the standard, increased organic pollution of the watercourse was noted in the summer, the accumulation of mineral phosphorus was observed in the summer and autumn periods without noticeable eutrophication of the water body. The parameters for assessing the impact of cage-type fish farming on a flowing water body are highlighted. The results make it possible to assess the impact of cage farming on a water body and can be used to optimize fish growing conditions and preserve the ecological well-being of the reservoir. 

The content of Fe, Zn, Cu, Ni, Cd, Pb, and Mn in fertilized caviar, pink salmon and chum salmon larvae and larvae from three fish hatcheries in the Sakhalin region before feeding, as well as in chum salmon larvae from spawning mounds from natural spawning grounds, was studied; the microelement composition of zygotes was compared with the gametes of producers. An increase in the concentration of trace elements after fertilization of eggs was not observed for all metals. After hatching, a sharp drop in metal levels was observed due to the loss of the shell and perivithelline fluid.; In the subsequent stages of early ontogenesis, the metal content in the fish body increased. The maximum fluctuations in the concentrations of trace elements occur during the early ontogenesis of salmon, while the change in concentration is due not so much to external factors as to the transition to the next stage of development.

In the context of the growing shortage of water and land resources, aquaponics technologies represent a promising alternative for highly productive food production. Through the use of nutrient waste from aquaculture, hydroponics receives organic fertilizer, which eliminates the use of (synthetic) nutrients and neutralizer conditioners for water purification. One of the most important tasks for producers is to optimize the use of water resources. This study shows the effect of the aquaponic system on the content of hydrobiont metabolism products in water – phosphates, nitrites, and nitrates. A comparative analysis of the growth and average daily growth of microgreens with control plants was also carried out.

One of the key objectives faced by enterprises in the food industry is the production of high-quality and safe food products. An essential condition for achieving this goal is the development of relevant regulatory documentation for food production that complies with the requirements of the Technical Regulations of the Eurasian Economic Union (EAEU). This study presents an analysis of the current technological instructions for the production of salted edible fish products using the spiced salting method, in accordance with the modern regulatory framework. These technological instructions were developed over 30 years ago and require revision under present-day conditions. Based on the conducted analysis, it is proposed to develop a unified technological instruction for the production of salted edible fish products (spiced salting method).

This study is devoted to the investigation of chitinolytic enzymes from the hepatopancreas of two commercially exploited crabs in the North-West region: the Red King crab (Paralitho- des camtschaticus) and the snow crab (Chionoecetes opilio). The results of the study demonstrate the presence of endo- and exochitinase activity in enzyme preparations, allowing for various types of chitin biotransformation. Using these enzymes, it is possible to depolymerize chitin into low-molecular-weight chitin and chitin oligomers, as well as to obtain the monomer N-acetylglucosamine. The authors have shown that crab hepatopancreas can be used as a raw material for obtaining chitinolytic enzymes, which allow for the enzymatic transformation of natural chitin into low-molecular-weight oligosaccharides and N-acetylglucosamine.