Ecological Safety of Coastal and Shelf Zones of Sea Ecological Safety of Coastal and Shelf Zones of Sea 2413-5577 20230408 Research Article Self-Purification Capacity of Sevastopol Bay Ecosystems in Relation to Inorganic Forms of Nitrogen and Phosphorus from 2012 to 2020 Mezentseva I. V.
Russian Federation
mez-irina@mail.ru Sovga E. E.
Russian Federation
esovga@mhi-ras.ru Khmara T. V.
Russian Federation
xmara@mhi-ras.ru Sevastopol Branch of the N. N. Zubov State Oceanographic Institute Sevastopol Russian Federation Marine Hydrophysical Institute of RAS Sevastopol Russian Federation 20 12 2023 2023 4 101 115 21 08 2023 11 10 2023 15 09 2023 Copyright © 2023, I. V. Mezentseva, E. E. Sovga, T. V. Khmara 2023 I. V. Mezentseva, E. E. Sovga, T. V. Khmara https://creativecommons.org/licenses/by-nc/4.0/ https://ecological-safety.ru/en/repository/issues/2023/04/08/

The paper uses the 2012-2020 joint oceanographic database of MHI RAS and SB FSBI SOI to estimate the self-purification capacity of Sevastopol Bay ecosystems in relation to biogenic nitrogen and phosphorus. The assimilation capacity and its specific value were calculated using the balance method. The paper estimates the average and maximum concentrations of inorganic phosphorus (PO₄) and nitrogen (NO₂, NO₃, NH₄), as well as the average and maximum rates and time of removal of these nutrients from the bay ecosystems. The paper shows changes in the percentage of forms of inorganic nitrogen (NO₂, NO₃, NH₄) in the water area of all parts of Sevastopol Bay for two periods (1998-2012 and 2012-2020). These changes had a greater impact on the content of the reduced form of ammonium nitrogen which has increased in all ecosystems of the bay in recent years. Changes in the self-purification capacity of the bay ecosystems were manifested as a spread of data on the assimilation capacity of the study ecosystems in relation to nutrients. At the same time, the lowest self-purification capacity was observed for the ecosystem of the eastern part of the bay. The paper assesses possible causes of the observed situation, which are associated with changes in the wind regime over the bay water area in the last decade and the resulting formation of the system of surface currents. The surface currents in the bay under prevailing easterly winds were calculated using the computational modeling method. The paper shows that an increase in the frequency of such winds contributes to increased ventilation of the waters of Yuzhnaya Bay and a more intense input of pollutants in the westerly direction. The paper analyzes the reasons for deterioration in the self-purification ability of the eastern part of the bay in the last decade in relation to all inorganic forms of nitrogen and phosphates. It was shown that changes in the self-purification ability of ecosystems throughout the Sevastopol Bay waters were associated with an increase in the recreational load on the bay coast.

 Sevastopol Bay biogenic nitrogen biogenic phosphorus ecosystem self-purification ability assimilation capacity surface currents The study was performed under state assignment of MHI RAS on topic no. 0827-2020-0004 "Coastal research".

About the authors:

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: 0000-0001-9771-0380, mez-irina@mail.ru

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

Contribution of the authors:

Irina V. Mezentseva – calculation of the assimilation capacity for ecosystems of parts of Sevastopol Bay, analysis of calculation results

Elena E. Sovga – study task statement, analysis of methods for calculating the assimilation capacity, comparison of assimilation capacity values for ecosystems of different parts of Sevastopol Bay, formation of the article

Tatiyana V. Khmara – calculations, discussion of the study results, data presentation in the text, data analysis, manuscript revision

All the authors have read and approved the final manuscript.

Article text not included.

REFERENCES SimonovA.I. RyabininA.I. Hydrometeorology and Hydrochemistry of Seas. Vol. 4. The Black Sea. Iss. 3. Modern State of the Black Sea Waters Pollution Sevastopol ECOSI-Gidrofizika 1996 230 (in Russian) LopukhinA.S. OvsyanyE.I. RomanovA.S. KovardakovS.A. SysoevaI.V. BraynzevaYu.V. RylkovaO.A. GavrilovaN.A. GubanovV.V. Seasonal Peculiarities of Hydrologic-Hydrochemical Structure of Sevastopol Bay Water, Microplankton and Distribution of its Biochemical Components (the Black Sea, Observations of 2004-2005) Ekologicheskaya Bezopasnost' Pribrezhnyi i Shel'fovoy Zon i Kompleksnoe Ispol'zovanie Resursov Shel'fa Sevastopol ECOSI-Gidrofizika 2007 15 74 109 (in Russian) IvanovV.A. OvsyanyE.I. RepetinL.N. RomanovA.S. IgnatyevaO.G. Hydrological and Hydrochemical Regime of the Sebastopol Bay and its Changing under Influence of Climatic and Anthropogenic Factors Sevastopol MHI NAS of Ukraine 2006 90 (in Russian) SovgaE.E. MezentsevaI.V. KotelyanetsE.A. Assimilation Capacity of the Marine Shallow Water Ecosystems with Various Anthropogenic Impacts as the Estimation Method of Its Self-Purification Ability Problems of Ecological Monitoring and Ecosystem Modelling 2017 28 4 38 51 10.21513/0207-2564-2017-4-38-51 (in Russian) SovgaE.E. MezentsevaI.V. KhmaraT.V. Natural-Climatic and Anthropogenic Factors Determining the Self-Purification Capacity of Shallow-Water Marine Ecosystems in Relation to Reduced Nitrogen Forms Ecological Safety of Coastal and Shelf Zones of Sea 2021 3 23 36 10.22449/2413-5577-2021-3-23-36 (in Russian) SovgaE.E. MezentsevaI.V. SlepchukK.A. Comparison of Assimilative Capacity and Trophic Index for Various Parts of the Sevastopol Bay Water Area Ecological Safety of Coastal and Shelf Zones of Sea 2020 3 63 76 10.22449/2413-5577-2020-3-63-76 (in Russian) SovgaE.E. MezentsevaI.V. KhmaraT.V. Simulation of Seasonal Hydrodynamic Regime in the Sevastopol Bay and of Assessment of the Self-Purification Capacity of its Ecosystem Fundamental and Applied Hydrophysics 2022 15 2 110 123 10.59887/fpg/92ge-ahz6-n2pt IvanovV.A. TuchkovenkoYu.S. Applied Mathematical Water-Quality Modeling of Shelf Marine Ecosystems Sevastopol ECOSI-Gidrofizika 2008 311 (in Russian) IzraelYu.A. TsybanA.V. Anthropogenic Ecology of the Ocean Moscow Gidrometeoizdat 1989 529 (in Russian) SovgaE. MezentsevaI. VerzhevskalaL. Assimilation Capacity of the Ecosystem of Sevastopol Bay OzhanE. Proceedings of the Twelfth International Conference on the Mediterranean Coastal Environment MEDCOAST 2015 Varna, Bulgaria 2015 1 317 326 RepetinL.N. BelokopytovV.N. LipchenkoM.M. Wind and Wave Perturbations in the Southwest Crimean Coast Ekologicheskaya Bezopasnost' Pribrezhny i Shel'fovoy Zon i Kompleksnoe Ispol'zovanie Resursov Shel'fa Sevastopol ECOSI-Gidrofizika 2003 9 13 28 (in Russian) SovgaE.E. KhmaraT.V. Influence of the Chernaya River Runoff during High and Low Water on the Ecological State of the Apex of the Sevastopol Bay Water Area Physical Oceanography 2020 27 1 28 36 10.22449/1573-160X-2020-1-28-36 KondratevS.I. VidnichukA.V. Local Seasonal Hypoxia and Hydrogen Sulphide Formation in the Bottom Waters of the Sevastopol Bay in 2009-2019 Ecological Safety of Coastal and Shelf Zones of Sea 2020 2 107 121 10.22449/2413-5577-2020-2-107-121 (in Russian)