Ecological Safety of Coastal and Shelf Zones of Sea Ecological Safety of Coastal and Shelf Zones of Sea 2413-5577 20250106 Research Article Intensity of Coastal Upwellings of the Southern Coast of Crimea and their Impact on the Oxygen Regime of the Water Area Sovga E. E.
Russian Federation
science-mhi@mail.ru Khmara T. V.
Russian Federation
xmara@mhi-ras.ru Mezentseva I. V.
Russian Federation
mez-irina@mail.ru Marine Hydrophysical Institute of RAS Sevastopol Russia Sevastopol Branch of the Federal State Budgetary Institution N. N. Zubov State Oceanographic Institute Sevastopol Russia 31 03 2025 2025 1 96 111 18 06 2024 17 12 2024 03 09 2024 Copyright © 2025, E. E. Sovga, T. V. Khmara, I. V. Mezentseva 2025 E. E. Sovga, T. V. Khmara, I. V. Mezentseva https://creativecommons.org/licenses/by-nc/4.0/ https://ecological-safety.ru/en/repository/issues/2025/01/06/

The paper analyses long-term data of the MHI Oceanological Data Bank for spring-summer seasons (May-September) of 1986-2000 and 2007-2023 and assesses the conditions of upwelling occurrence, their duration, influence on the change of temperature and oxygen regimes and content of nutrients in the water area of Goluboy and Yalta Bays. Fourteen upwellings were detected during the mentioned periods. The volume of analysed data was 3288 values of depth, temperature, sigma-t, oxygen content and nutrients. Upwellings recorded in the first period (1986-2000) were observed only in the Yalta Bay water area. They are characterised by large temperature variations, significant changes in sigma-t and for May upwellings by very high values of oxygen content. An analysis of the current MHI database from 2007 to 2023 allowed us to identify upwellings in the waters of Goluboy Bay, including the area of the stationary oceanographic platform, in July 2007, May 2010, 2012 and 2013, June and September 2013 and June 2021. We compared the temperature, coastal sigma-t and oxygen content for May and June 2012, 2013 and June 2021 and concluded that the intensity of upwellings had significantly decreased, the reasons for which are still unclear and may require further research. The paper considers differences in the content of biogenic nitrogen and phosphorus in the coastal water areas of the Southern Coast of Crimea during upwellings. These differences were manifested in the increase in the content of mineral forms of phosphorus and insignificant change in the content of mineral complexes of nitrogen. The analysis of the used database for these periods showed the insufficiency of target measurements and the need to adjust the monitoring system, especially in the spring-summer period, when the probability of upwelling is maximum.

 coastal upwelling Southern Coast of Crimea temperature regime oxygen regime nutrients The work was performed under state assignment of MHI RAS on topic FNNN-2024-0016 "Studies of spatial and temporal variability of oceanological processes in the coastal, near-shore and shelf zones of the Black Sea influenced by natural and anthropogenic factors on the basis of in situ measurements and numerical modelling".

About the authors:

Elena E. Sovga, Leading Research Associate, Marine Hydrophysical Institute of RAS (2 Kapitanskaya St., Sevastopol, 299011, Russian Federation), DrSci (Geogr.), ORCID ID: 0000-0002-0670-4573, ResearcherID: A-9774-2018, science-mhi@mail.ru

Tatiyana V. Khmara, Research Associate, Marine Hydrophysical Institute of RAS (2 Kapitanskaya St., Sevastopol, 299011, Russian Federation), Scopus Author ID: 6506060413, ResearcherID: C-2358-2016, xmara@mhi-ras.ru

Irina V. Mezentseva, Senior Research Associate, Sevastopol Branch of the N. N. Zubov State Oceanographic Institute (61 Sovetskaya St., Sevastopol, 299011, Russian Federation), PhD (Geogr.), ORCID ID: 0000-0001-9771-0380, mez-irina@mail.ru

Contribution of the authors:

Elena E. Sovga – study task statement, database analysis, discussion of the results, article writing and editing

Tatiyana V. Khmara – preparation of graphic material, discussion of the results, article editing

Irina V. Mezentseva – provision and analysis of database on Yalta Bay, discussion of the results

All the authors have read and approved the final manuscript.

Article text not included.

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