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Fisheries Science of Ukraine, 2026; 2(76): 25-47
DOI: https://doi.org/10.61976/fsu2026.02.025
UDC 639.2:597.2/.5:504.45(262.5)

Received: 17.02.2026
Received in revised form: 13.03.2026
Published: 30.06.2026

Age structure of fish populations as a factor in forming commercial catches in the Shabolatskyi Estuary

M. Burhaz, This email address is being protected from spambots. You need JavaScript enabled to view it. , ORCID ID 0000-0003-1551-6002, I.I. Mechnikov Odesa National University, Odesa

Purpose. Establishing quantitative patterns of the relationship between the age structure of populations of main commercial fish species and the long-term dynamics of their catches as well as substantiating the feasibility of using demographic parameters as indicators for managing fish resources of the estuary Shabolatskyi.

Methodology. The study was based on the analysis of commercial fishery statistics for 2001–2025 and results of ichthyological observations for 2009–2025. The age structure of populations of the main commercial fish species was assessed by age groups 0+–5+. To identify patterns in the formation of stocks, the method of comparing time series and correlation analysis using the Pearson coefficient were used. Statistical significance of relationships was assessed at the p < 0.05 level.

Findings. The formation of commercial stocks of mullet (Mugilidae) is largely determined by the abundance of individuals of older age groups (r = 0.84–0.88), which indicates the inertial nature of the dynamics of their populations. Catches of silverside (Atherina spp.) and gobies (Gobiidae) demonstrate dependence on the abundance of younger age groups and the productivity of the current year’s generations (r = 0.42–0.66). It was found that the deterioration of the hydrological regime and restrictions on water exchange after 2022 caused a decrease in the proportion of younger age groups in populations, which was accompanied by a significant decline in fish productivity of the studied water body.

Originality. For the first time, a comprehensive quantitative assessment of the impact of the age structure of populations on the stability of commercial catches was conducted for the estuary Shabolatskyi and the use of demographic parameters as prognostic indicators of the state of the ichthyocenosis was substantiated.

Practical Value. The feasibility of using adaptive approaches to fisheries regulation is substantiated, in particular, establishing stable medium-term limits for mullet fish and flexible operational regulation for the catch of species with a short life cycle. The results obtained can be used in the development of measures to optimize the fisheries exploitation of estuarine ecosystems of the North-Western Black Sea Region. Scientific understanding of the role of age structure as a functional element in shaping the dynamics of fish resources, integrating the processes of recruitment, natural mortality, and commercial fishery has been expanded.

Keywords: ichtyopopulations, mullet, gobies, correlation analysis, recruitment, commercial stock, Black Sea estuaries.

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