S. V. Shipulin’s research while affiliated with All-Russian Research Institute Fisheries and Oceanography and other places

The article presents an analysis of the boundaries of the Volga pre-estuarine forbidden space in retrospect and in the present period. The dynamics of the area of the Volga pre-estuary forbidden space is shown, which over the last century has decreased by more than 10 times. Most of the water area of the Volga pre-estuary forbidden space is currently located on land. Reason: drop in the level of the Caspian Sea and a decrease in the volume of Volga runoff. Using the example of a separate northwestern section of the delta and delta front of the river The Volga River clearly shows how the coastline of the Caspian Sea and, accordingly, the protective zone of the Volga pre-estuary forbidden space have changed. Taking into account the current water and fishery situation, the dynamics of the fall in the level of the Caspian Sea, proposals were made to update the northern boundary of the space, draw the coastline along the mark of 28.7 m BS and expand the protected areas.

The aim of the paper is an expert assessment of the quantitative, qualitative and species composition of IUU-fishing and their dynamics for 2017-2021. Analysis and synthesis of materials of ichthyologic examinations received from law enforcement agencies in the Volga-Caspian branch of “VNIRO” (“CaspNIRKh”). For the first time, an assessment of IUU fishing of sturgeon in the Caspian Sea for 2017-2021 was carried out. Quantitative and qualitative assessments of IUU-fishing, its species composition and their dynamics for 2017-2021 were obtained. The results of this study canbe used in predictive models of the dynamics of sturgeon stocks and in the analysis of the situation with the protection of these fish species in the Caspian Sea.

The aim: description of the subspecies of dinophyte algae Ceratium tripos var. balticum , first discovered in the Caspian Sea. Materials : Monitoring observations of the state of the Caspian ecosystem and the food supply of commercial pelagic fish species: collection of hydrobiological material in the Middle Caspian during a sprout survey in the summer of 2024 on the IS «Caspian Researcher» according to the standard grid of stations adopted by the Volga-Caspian branch of the State Scientific Center of the Russian Federation «VNIRO» («CaspNIRKH»). Phytoplankton samples were collected using a BSR bathometer (4 L), fixed with formalin and concentrated. During laboratory processing of the material, the species composition was determined, and the abundance and biomass of planktonic algae were calculated. Research results: when processing phytoplankton samples, a representative of the genus Ceratium , which was not found in the Caspian Sea, was discovered. Scientific novelty: for the first time, a description of a new species of dinophyte algae Ceratium tripos var. balticum (Dinoflagelta: Dinophyceae). Practical significance: due to the fact that the species is large in size, it is inaccessible to zooplankton phytophages, and since there are no species capable of consuming it as food and thereby limiting its development, its rapid development is possible, which may entail a restructuring of the main connections and energy flows in the ecosystem, as happened when the diatom Pseudosolenia calcar-avis invaded the Caspian Sea.

The aim of this research was to assess the current abundance of the Caspian seal population on ice in the Russian part of the North Caspian using instrumental methods of aerial survey in the infrared and optical ranges using a manned aircraft and UAV. The main method of the research was a multispectral aerial survey, the essence of which is to survey seal haulouts synchronously in the infrared and optical ranges. In winter, 90% of all mature individuals gather on the ice substrate of the Northern Caspian for reproduction, lactation and mating and spend a significant part of their time outside the water, which greatly facilitates their detection and counting. The aerial survey was carried out in parallel from two types of aircraft — the La‑8 manned amphibious aircraft and unmanned aerial vehicles equipped with high-resolution cameras in optical and infrared modes, which ensure reliable registration of seals on ice. Novelty: the advantage of joint use of a manned aircraft and a UAV equipped with special photo and infrared equipment is noted. As a result of the research, the flights were carried out from February 20 to March 5, 2023 in the daytime in good visibility conditions at an altitude of 200 to 300 m. amounted to 19704 individuals, including 4062 puppies. The animals were located in the southeastern part of the ice cover near the air demarcation line between the Russian Federation and the Republic of Kazakhstan on the ice edge. An increase in the number of seals was recorded due to migrating individuals from Kazakhstan. Breeding of the Caspian seal in winter 2022/2023 proceeded in a satisfactory manner. During the flight, it was found that there were no fresh releases of seals on the coast of Dagestan. Separate old carcasses, partially torn to pieces, were registered only on the shores of the Agrakhan Peninsula. Practical value : the obtained data are needed to assess the current abundance of the Caspian seal population in the Caspian Sea.

Based on research materials from 2003–2022, a review of the dynamics of stocks of aquatic biological resources for an unregulated section of the Volga River below the Volga hydroelectric dam within the Astrakhan region was carried out. The reasons, mainly of anthropogenic nature, causing changes in stocks are shown. The multidirectional nature of changes in the state of populations of aquatic biological resources depending on the sensitivity of species to environmental factors and their consumer value is demonstrated. The steps aimed at improving the situation are proposed.

The aim of the work: characterization of juveniles released from sturgeon hatcheries into the natural habitat with individual identification of individuals. Methods: Ichthyological researches in the Volga River and its watercourses were surveyed using a 4.5 m fry trawl; in the western part of the Northern Caspian, a trawl survey was carried out using a 9 m trawl and the developed grid of stations, adjusted to take into account the sea level decrease. The trophological material was processed by the quantitative-weight method, followed by the calculation of private and general indices of the filling of the digestive tracts. Molecular genetic methods for the analysis of microsatellite loci and sequencing of a fragment of the control region of mitochondrial DNA were used. Novelty: the origin of the Russian sturgeon and the contribution of artificial reproduction from Russian sturgeon hatcheries to the Volga- Caspian fishery basin were determined by molecular genetic methods. Results: The composition of food organisms and the degree of fattening of Russian sturgeon juveniles after their migration to the sea were determined. The contribution of artificial reproduction from Russian sturgeon hatcheries to the replenishment of the Russian sturgeon population of the Volga- Caspian basin in the period 2016–2021 for fingerlings was averaged 80 %. Practical significance: The intensity of downstream migration in the Volga River and its watercourses of juveniles released from sturgeon hatcheries was studied. The presented data was made it possible to determine the main localization sites of Russian sturgeon juveniles depending on the species composition and abundance of food organisms in the northwestern part of the Caspian Sea. Based on the results of genotyping of spawners at sturgeon hatcheries and juveniles caught in the Northern Caspian, an assessment was made of the effectiveness of the work of the sturgeon hatcheries in 2016–2021.

За 125 лет КаспНИРХ прошёл путь от одной из первых в России ихтиологической лаборатории до современного научно-исследовательского учреждения — флагмана рыбохозяйственной науки на Каспии.

In recent years, the state of the Caspian roach reserves has been repeatedly discussed at different levels and sites. The number of this species is declining, catches are falling. Based on the instructions of the Volga-Caspian Scientific and Commercial Council of the Volga-Caspian Fisheries Basin, a draft comprehensive program for the conservation and restoration of roach stocks is being developed, in which it is planned to consider the imposed restrictions on fishing, the possibility of artificial reproduction, the need for in-depth monitoring of the population. Observing negative trends for a number of years, understanding the social significance of the species, immediate emergency measures are needed to preserve and restore the Caspian roach in order to avoid its loss.