The hematological parameters of nelma (Stenodus leudehthys nelma), broad whitefish (chir, Coregonus nasus), muksun (Coregonus muksun), and peled (Coregonus peled) reared in a recir culating aquaculture system (RAS) are presented. A wide range of variation was observed in most parameters, indicating species-specific and individual characteristics of the cultured fish. High levels of total serum protein, hemoglobin concentration, and red blood cell count were detected in muksun and peled. The leukocyte profile ofpeled indicates a high immunophysiological status and broad adaptive capacity under industrial rearing conditions. Qualitative changes in the blood profile in nelma characterizing this species as more sensitive to rearing conditions. The obtained hematological value for chir and muksun may indicate moderate adaptive capacity when cultured under industrial conditions
Sterlet т the Severnaya Dvina river is not in demand by fishery due to the peculiarities of its distribution during the periods allowed for fishing. The development of the volumes of sterlet issued to users in 2012-2021 amounted to 19.5-43.4%, and the development of the total allowable catch is even less - 7.9-36.1%. The reason for the refusal to regulate fishing by establishing the total allowable catch is the development of TAC is the production area over the past three years less than 70% annually. Thus, the basis for the exclusion of sterlet from the list of species for which TAC is established in the Northern Fisheries Basin has existed for more than 10 years. However, measures to eliminate the administrative barrier of fisheries and the adaptation of fisheries legislation to modern conditions are not being taken.
A study of the growth and dynamics of the size and age structure of the population of the Gustera Blicca bjoerkna in the Uglich reservoir was conducted based on a comparison of two contrasting periods: active fishing (1972-1973) and its current absence (2012-2024). It was found that the modern population is characterized by a wide range (10.5-27.1 cm) and age (3+-14+) a range with a high proportion of older age groups (up to 32%). A significant increase in average length, body weight, and height parameters (Linf, K) according to the Bertalanffy equation has been revealed in the modern period. The use of the LBI (Length-Based Indicators) indicator method confirmed the stable and prosperous state of the population: the values of the indicators for the conservation of juveniles (L c /L mat , L 25 /L mat ) and large individuals (L 95 /L inf ) correspond to the targets, and the indicators L mean /L opt and L mean /L f =m are stable, which indicates the compliance of the population MSY concepts. Unlike bream, gustera did not show a density-dependent effect after the cessation of fishing, which is probably due to its trophic plasticity (euryphagia) and the possible positive effect of climatic changes on feeding conditions
Based on long-term data, the biological parameters and stock status of the Curonian Lagoon sabrefish were analyzed. In recent years, а decline in the size аnd weight of individuals in commercial catches has been observed. In 2022, abundance and biomass indices reached their highest values for the entire observation period, exceeding the long-term average by more than three times, which was due to the recruitment of several successful year-classes into the fishery. Using a cohort model, the stock status of the species was calculated and forecast for 2027. The current status of the sabrefish population is assessed as satisfactory.
Recreational fishing is аn integral part of life for people in the Fаг North. The research provides a qualitative and quantitative analysis of the development of recreational fishing in the Arkhangelsk region at the present stage. Several types of recreational fishing are developing in the region. Traditionally, unorganized fishing is the most widespread. A significant portion of fishermen catch fish all year round. Fishermen most often use hook fishing gear. Fish catches amount to up to 5 kg. Recreational fishing is actively developing in the areas. We consider it advisable to continue monitoring fisheries, аs well аs improve approaches to its regulation in order to balance thе interests of fishermen while unconditionally preserving stocks of valuable aquatic bioresources
The article provides information about the biology of the zander Alburnus alburnus (Linnaeus, 1758) in the Terek River basin in Kabardino-Balkaria. It provides a brief description of the zander’s habitat, which includes artificial reservoirs within the city of Nalchik. The article also discusses the distribution of the zander in the republic and its preferred habitats, as well as its relative abundance and its role in freshwater ecosystems. The article also focuses on the zander’s diet and parasitic infestations. It has been established that the basis of the bleak diet is zooplankton, in particular, the ciliated Bosmina longirostris Muller, 1776 and the cope pod Cyclops strenuus (Fischer, 1851). The role of aerial insects and benthic invertebrates (such as Endochironomus stackelbergi Goetghebuer, 1935) is also important
An expedition conducted in 2024-2026 in the marine waters of Northwest African countries may potentially increase the catch of commercial fish species that are practically new to Russia—John Dory, Pristipomu, Leerfish, Pagel, апа Trigla-lyra. These fish species have been found to be safe for human consumption in accordance with СU TR 021/2011 and EAEU TR 040/2016. These are primarily low-fat, high-protein species. John Dory and leerfish alone contain approximate- Iу 3.0% fat, placing them among е medium-fat fish. The fatty acid composition of the muscle lipids of the fish studied was found to be nearly 50% saturated, possibly due to the specific food sources. All studied fish species contain essential amino acids, phosphorus, potassium, and iron, and are valuable raw materials for both public catering апа the production of traditional products.
The article examines the potential for increasing the harvest of underutilized aquatic biological resources (ABR), including zooplankton аnd mesopelagic fish, for the production оf marine-derived feed ingredients such as fishmeal and fish oil for use in aquaculture and livestock production. Despite the substantial biomass of these currently unexploited ABR, the prospects for expanding their catch volumes remain constrained by several factors: (i) limited knowledge of their spatiotemporal distribution; (ii) low daily catch volumes аnd short fishing seasons, which, in combination with current product price levels, render investments economically unviable; (iii) the absence оf specialized fishing methods and gear; (iv) overlap with the fishing periods of commercially valuable species; (v) specific features of their biochemical composition that complicate processing; (vi) and the high capital investment required to establish economically sustainable harvesting operations. Based on a comprehensive analysis of these constraints, the study concludes that a significant increase in the utilization of underexploited ABR for the production of marine feed ingredients is unlikely in the near term.
A factor analysis of the sturgeons of the Pont-Amur sector has been performed. Morphometric differences are clear, and based on the author’s expression, the period of the common usage of the Russian, Persian, and Adriatic sediments is determined based on the data of mitotypic analysis. The reference to glaciations and transgressions is given. The connection of Lake Baikal with the Ob and Amur is planned
The article examines the peculiarities of cost formation in the cultivation of juvenile rainbow trout in an experimental installation of a closed-loop water supply (RAS) on the basis of a specialized aquaculture center of an educational organization. The authors conducted a detailed analysis of the structure of transaction costs, including the volume and cost of resources consumed. The paper presents data on the growth dynamics of planting material while maintaining stable hydrochemical parameters of the aquatic environment. It has been established that with optimal use of highquality feed, the main share in the cost structure shifts towards energy consumption. This factor makes it possible to reconsider the approach to the purchase оf planting material, giving priority to its qualitative characteristics rather than the minimum cost. In conclusion, practical recommendations are formulated for optimizing technological solutions aimed at reducing production costs and increasing the profitability of fish farms using ULTRASOUND systems.
The paper provides materials on the history of the creation and operation of spawning farms in the Volga River delta. It is shown that during the period of falling Caspian Sea levels and worsening spawning conditions for semi-aquatic fish (roach, carp, bream and walleye), due to the low water content of all rivers flowing into the Caspian, attention should be paid and work оп their artificial reproduction based оп previously developed technologies should be expanded.
Based оп the results оf bottom trawl surveys conducted the summer апа autumn of 2019 and 2021 in the northern and northwestern parts of the Sea of Okhotsk, as well as on archival data, it was revealed that the yellowfin sole (Limanda aspera) forms its main concentrations in the coastal areas of high productivity, particularly in the northern part of the North Okhotsk Sea: in the area of the Tauiskaya Bay and the adjacent waters of the Pritauisky District, as well as in the area of the village of Ayan (especially dense concentrations were found in the area of the Feodota Bay). At the same time, most of the biomass of this species was confined to depths up to 100 meters.
