Biological characterization and spatial distribution of roach Rutilus rutilus heckelii and common bream Abramis brama juveniles in the Don River in 2020
The data collected during the scientific monitoring of the spawning run of roach Rutilus rutilus heckelii and common bream Abramis brama in the Don River have been analyzed. Investigation of the biological characteristics, spatial distribution and specific features of the downward migration of fish juveniles was carried out in the Lower Don area stretching from Romanovskaya Settlement to the Don River Delta in May–October, 2020. The obtained results show significant gain in average length and weight of roach and bream juveniles in the spring – summer season of 2020 and its absence in the summer – autumn season, which was caused by the downward migration of the partially grown juveniles in the Taganrog Bay. Hauls of fry drag nets showed that the juveniles in the investigated water bodies kept to the shallow coastal waters. Quantitative assessment of the spatial distribution of juveniles indicates spatial heterogeneity of their aggregations and moderately productive spawning run in the context of low water content in 2020. Based on the outcomes of the scientific monitoring, the abundance of roach juveniles was assessed to be 49.3 million ind., and for bream juveniles it equaled 30.4 million ind. In the future, the research results factoring in statistical processing will make it possible to analyze the long-term dynamics of the biological characteristics of roach and bream juveniles.
| Main Authors: | , , , |
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| Format: | Journal Contribution biblioteca |
| Language: | Russian |
| Published: |
2021
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| Subjects: | Biomass, Abundance, Rutilus rutilus, Abramis brama, Biological properties, Length, Weight, Численность, Биомасса, Биологические характеристики, Тарань, Лещ, Мальковая волокуша, ASFA_2015::J::Juveniles, ASFA_2015::G::Geographical distribution, ASFA_2015::S::Spawning migrations, |
| Online Access: | http://hdl.handle.net/1834/41443 |
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| Summary: | The data collected during the scientific monitoring of the spawning run of roach Rutilus rutilus heckelii and common bream Abramis brama in the Don River have been analyzed. Investigation of the biological characteristics, spatial distribution and specific features of the downward migration of fish juveniles was carried out in the Lower Don area stretching from Romanovskaya Settlement to the Don River Delta in May–October, 2020. The obtained results show significant gain in average length and weight of roach and bream juveniles in the spring – summer season of 2020 and its absence in the summer – autumn season, which was caused by the downward migration of the partially grown juveniles in the Taganrog Bay. Hauls of fry drag nets showed that the juveniles in the investigated water bodies kept to the shallow coastal waters. Quantitative assessment of the spatial distribution of juveniles indicates spatial heterogeneity of their aggregations and moderately productive spawning run in the context of low water content in 2020. Based on the outcomes of the scientific monitoring, the abundance of roach juveniles was assessed to be 49.3 million ind., and for bream juveniles it equaled 30.4 million ind. In the future, the research results factoring in statistical processing will make it possible to analyze the long-term dynamics of the biological characteristics of roach and bream juveniles. |
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