Concentrations of Nutrients in the Pore Waters of the Sevastopol Bay Bottom Sediments

K. I. Gurov*, A. V. Varenik, M. A. Myslina

Marine Hydrophysical Institute of RAS, Sevastopol, Russia

* e-mail: gurovki@gmail.com

Abstract

The paper aims to assess features of the spatio-temporal distribution of nutrient concentrations in the pore waters of the upper sediment layer based on modern in situ data. Samples were collected using a DCh-0.025 bottom grab sampler. Pore water was extracted by centrifugation (Elmi CM-6MT centrifuge). Concentrations of inorganic nutrients were determined photometrically using a KFK-3KM spectrophotometer and a Skalar San++ continuous flow autoanalyser (the Netherlands) after filtration (0.45 µm membrane), except for ammonium samples. Ammonium nitrogen was measured by a modified Sagi–Solorzano method. Correlation coefficients and their significance were calculated using the Statistica software. Qualitative and quantitative characteristics of the spatial distribution of nutrient concentrations in pore waters from the upper sediment layer were obtained for samples collected in Sevastopol Bay in 2024. Seasonal variability was revealed, and relationships with station location, sediment type and geochemical properties of the solid phase were established. In the upper sediment layer of Sevastopol Bay, a weakly alkaline reducing environment predominated: pH and Eh values ranged from 7.1 to 7.8 and from 0 to −270 mV, respectively. Over the year, mean concentrations varied within the following ranges: nitrites were 0.23–0.37 µM; nitrates were 0.71–3.61 µM; phosphates were 11.91–25.84 µM; silicic acid was 21.14–297.30 µM; and ammonium was 139.64–543.76 µM. A negative correlation was found between ammonium and phosphate concentrations and Eh (r = −0.8 and −0.7, respectively), while phosphates and silicic acid showed positive correlations with pH (r = 0.7 and 0.6, respectively). The weakly alkaline reducing conditions observed in the sediments of Sevastopol Bay are the main factor controlling elevated ammonium and phosphate concentrations and low nitrate levels. Intra-annual dynamics of nutrient concentrations in pore waters are influenced by hydrological parameters (water temperature), hydrodynamic conditions in different parts of the bay (autumn–winter mixing), as well as by additional local inputs of nutrients with stormwater and sewage discharges.

Keywords

Sevastopol Bay, bottom sediments, redox conditions, pore waters, nutrients, nitrates, nitrites, phosphorus, silicon, ammonium

Acknowledgments

The work was carried out under the state assignment of MHI RAS on topic No. FNNN-2024-0001 “Fundamental studies of the processes that determine fluxes of matter and energy in the marine environment and at its boundaries, the state and evolution of the physical and biogeochemical structure of marine systems in modern conditions”.

About the authors

Konstantin I. Gurov, Researcher, Marine Hydrophysical Institute of RAS (299011, Russia, Sevastopol, Kapitanskaya St., 2), PhD (Geogr.), ORCID ID: 0000-0003-3460-9650, Scopus Author ID: 57200248245, ResearcherID: L-7895-2017, gurovki@gmail.com

Alla V. Varenik, Senior Researcher, Marine Hydrophysical Institute of RAS (299011, Russia, Sevastopol, Kapitanskaya St., 2), PhD (Geogr.), ORCID ID: 0000-0001-5033-4576, ResearcherID: H-1880-2014, Scopus Author ID: 56960448000, alla.varenik@mhi-ras.ru

Mariya A. Myslina, Junior Researcher, Marine Hydrophysical Institute of RAS (299011, Russia, Sevastopol, Kapitanskaya St., 2), ORCID ID: 0000-0002-0054-0379, myslina@mhi-ras.ru

For citation

Gurov, K.I., Varenik, A.V. and Myslina, M.A., 2026. Concentrations of Nutrients in the Pore Waters of the Sevastopol Bay Bottom Sediments. Ecological Safety of Coastal and Shelf Zones of Sea, (3), pp. 76–92.

References

  1. Gurova, Yu.S., Yakushev, E.V., Berezina, A.V., Novikov, M.O., Gurov, K.I. and Orekhova, N.A., 2023. Numerical Modelling of RedOx Condition Dynamics at the Water-Sediment Interface in Sevastopol Bay. Ecological Safety of Coastal and Shelf Zones of Sea, (2), pp. 71–90.
  2. Orekhova, N.A. and Varenik, A.V., 2018. Current Hydrochemical Regime of the Sevastopol Bay. Physical Oceanography, 25(2), pp. 124–135. https://doi.org/10.22449/1573-160X-2018-2-124-135
  3. Ivanov, V.A., Ovsyany, E.I., Repetin, L.N., Romanov, A.S. and Ignatyeva, O.G., 2006. Hydrological and Hydrochemical Regime of the Sebastopol Bay and its Changing under Influence of Climatic and Anthropogenic Factors. Sevastopol: MHI NAS of Ukraine, 90 p. (in Russian).
  4. Orekhova, N.A., Medvedev, E.V. and Ovsyany, E.I., 2018. Influence of the River Chernaya Water on Hydrochemical Regime of the Sevastopol Bay (the Black Sea). Ecological Safety of Coastal and Shelf Zones of Sea, (3), pp. 84–91. https://doi.org/10.22449/2413-5577-2018-3-84-91 (in Russian).
  5. Myslina, M.A., Varenik, A.V. and Tarasevich, D.V., 2024. Dynamics of Nutrients Concentration in the Chernaya River Waters (Crimean Peninsula) in 2015–2020. Physical Oceanography, 31(3), pp. 398–408.
  6. Egorov, V.N., Gulin, S.B., Malakhova, L.V., Mirzoeva, N.Y., Popovichev, V.N., Tereshchenko, N.N., Lazorenko, G.E., Plotitsina, O.V., Malakhova, T.V. et al., 2018. Rating Water Quality in Sevastopol Bay by the Fluxes of Pollutant Deposition in Bottom Sediments. Water Resources, 45(2), pp. 222–230. https://doi.org/10.1134/S0097807818020069
  7. Malakhova, L.V., Lobko, V.V., Malakhova, T.V. and Murashova, A.I., 2022. Comparative Assessment of Organochlorine Pollution of Bottom Sediments in Different Types of Water Bodies in the Sevastopol Region (Crimea). Chemistry for Sustainable Development, 30(2), pp. 169–181. https://doi.org/10.15372/CSD2022371
  8. Gurov, K.I. and Kotelyanets, E.A., 2022. Distribution of Trace Metals (Cr, Сu, Ni, Pb, Zn, Sr, Ti, Mn and Fе) in the Vertical Section of Bottom Sediments in the Sevastopol Bay (Black Sea). Physical Oceanography, 29(5), pp. 491–507.
  9. Soloveva, O.V. and Tikhonova, E.A., 2018. The Organic Matter Content Dynamics in the Sea Bottom Sediments of the Sevastopol Harbor Water Area. Scientific Notes of V.I. Vernadsky Crimean Federal University. Biology. Chemistry, 4(4), pp. 196–206 (in Russian).
  10. Paraskiv, A.A., Tereshchenko, N.N., Proskurnin, V.Yu. and Chuzhikova-Proskurnina, O.D., 2021. Change in Plutonium Sedimentation Fluxes into the Bottom Sediments of the Sevastopol Bay Before and After the Chernobyl NPP Accident. Marine Biological Journal, 6(2), pp. 69–82. https://doi.org/10.21072/mbj.2021.06.2.05
  11. Orekhova, N.A. and Konovalov, S.K., 2009. Oxygen and Sulfide in Bottom Sediments of the Sevastopol Bay. Ecological Safety of Coastal and Shelf Zones and Comprehensive Use of Shelf Resources, 18, pp. 48–56 (in Russian).
  12. Orekhova, N.A. and Konovalov, S.K., 2018. Oxygen and Sulfides in Bottom Sediments of the Coastal Sevastopol Region of Crimea. Oceanology, 58(5), pp. 679–688. https://doi.org/10.1134/S0001437018050107
  13. Middelburg, J.J. and Levin, L.A., 2009. Coastal Hypoxia and Sediment Biogeochemistry. Biogeosciences, 6(7), pp. 1273–1293. https://doi.org/10.5194/bg-6-1273-2009
  14. Seitzinger, S., Harrison, J.A., Böhlke, J.K., Bouwman, A.F., Drecht, G.V., Lowrance, R., Peterson, B. and Tobias, C., 2006. Denitrification Across Landscapes and Waterscapes: A Synthesis. Ecological Applications, 16(6), pp. 2064–2090. https://doi.org/10.1890/1051-0761(2006)016[2064:DALAWA]2.0.CO;2
  15. Sovga, Е.Е., Mezentseva, I.V. and Khmara, T.V., 2022. Simulation of Seasonal Hydrodynamic Regime in the Sevastopol Bay and of Assessment of the Self-Purification Capacity of Its Ecosystem. Fundamental and Applied Hydrophysics, 15(2), pp. 110–123. https://doi.org/10.48612/fpg/92ge-ahz6-n2pt (in Russian).
  16. Ovsyany, E.I., Artemenko, V.M., Romanov, A.S. and Orekhova, N.A., 2007. The Chernaya River Discharge as a Factor Affecting the Water-Salt Regime Forming and Ecological State of the Sevastopol Bay. Ecological Safety of Coastal and Shelf Zones and Comprehensive Use of Shelf Resources, 15, pp. 57–65 (in Russian).
  17. Mikhailova, E.N. and Shapiro, N.B., 2005. Simulation of the Circulation and Space Structure of Thermohaline Fields in the Sevastopol Bay with Regard for the Actual External Data (Winter, 1997). Physical Oceanography, 15(2), pp. 118–132. https://doi.org/10.1007/s11110-005-0035-0
  18. Morozov, A.N., Lemeshko, E.M., Shutov, S.A. and Zima, V.V., 2012. Currents in the Sevastopol Bay from ADCP-Observations (June, 2008). Morskoy Gidrofizicheskiy Zhurnal, (3), pp. 31–43 (in Russian).
  19. Lemeshko, E.M., Morozov, A.N., Shutov, S.A., Zima, V.V. and Chepyzhenko, A.A., 2014. [Currents in Sevastopol Bay Based on ADCP Observations, November 2014]. Ecological Safety of Coastal and Shelf Zones and Comprehensive Use of Shelf Resources, 28, pp. 25–30 (in Russian).
  20. Gruzinov, V.M., Dyakov, N.N., Mezenceva, I.V., Malchenko, Y.A., Zhohova, N.V. and Korshenko A.N., 2019. Sources of Coastal Water Pollution near Sevastopol. Oceanology, 59(4), pp. 523–532. https://doi.org/10.1134/S0001437019040076
  21. Sovga, E.E. and Khmara, T.V., 2020. 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, 27(1), pp. 28–36. https://doi.org/10.22449/1573-160X-2020-1-28-36
  22. Varenik, A.V., 2025. Nitrogen and Phosphorus Compounds in Atmospheric Deposition in Sevastopol, 2015–2023. Physical Oceanography, 32(1), pp. 84–98.
  23. Kondratev, S.I. and Vidnichuk, A.V., 2020. 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, (2), pp. 107–121. https://doi.org/10.22449/2413-5577-2020-2-107-121 (in Russian).
  24. Bagaev, A.V., Nikishin, V.V., Rauen, T.V., Verzhevskaya, L.V. and Scherbachenko, S.V., 2022. Local Changes of Physical and Biological Parameters of the Sevastopol Bay Surface Waters under the Influence of Rain Drainage. Physical Oceanography, 29(2), pp. 152–171.
  25. Mironov, O.G. and Alyomov, S.V., eds., 2018. Sanitary and Biological Studies of the South-Western Crimea Coastal Waters at the Beginning of XXI Century. Simferopol: ARIAL, 276 p. https://doi.org/10.21072/978-5-907118-89-8 (in Russian).
  26. Goryachkin, Yu.N. and Efremova, T.V., 2022. Anthropogenic Impact on the Lithodynamics of the Black Sea Coastal Zone of the Crimean Peninsula. Ecological Safety of Coastal and Shelf Zones of Sea, (1), pp. 6–30. https://doi.org/10.22449/2413-5577-2022-1-6-30
  27. Thamdrup, B. and Dalsgaard, T., 2002. Production of N₂ through Anaerobic Ammonium Oxidation Coupled to Nitrate Reduction in Marine Sediments. Applied and Environmental Microbiology, 68(3), pp. 1312–1318. https://doi.org/10.1128/AEM.68.3.1312-1318.2002
  28. Belkina, N.A., 2015. Phosphorus in the sediments of the Lake Onega. Izvestia: Herzen University Journal of Humanities & Sciences, 173, pp. 97–109. (in Russian).
  29. Belkina, N., Subetto, D., Efremenko, N., Potakhin, M. and Kulik, N., 2015. The Chemical Composition of Bottom Sediments in Northern Lake Ladoga as an Indicator of Long-Term Variations in the Lake Ecosystem. Transactions of KarRC RAS, (9), pp. 53–61. https://doi.org/10.17076/lim51
  30. Savenko, V.S. and Savenko, A.V., 2007. Geochemistry of Phosphorus in the Global Hydrological Cycle. Moscow: GEOS, 248 p. (in Russian).
  31. Boudreau, B.P. and Canfield, D.E., 1993. A Comparison of Closed- And Open-System Models for Porewater pH and Calcite-Saturation State. Geochimica et Cosmochimica Acta, 57(2), pp. 317–334. https://doi.org/10.1016/0016-7037(93)90434-x
  32. Van Cappellen, P. and Wang, Y., 1996. Cycling of Iron and Manganese in Surface Sediments; a General Theory for the Coupled Transport and Reaction of Carbon, Oxygen, Nitrogen, Sulfur, Iron, and Manganese. American Journal of Science, 296(3), pp. 197–243. https://doi.org/10.2475/ajs.296.3.197
  33. Jørgensen, B.B. and Kasten, S., 2006. Sulfur Cycling and Methane Oxidation. In: H.D. Schulz, M. Zabel, eds., 2006. Marine Geochemistry. Berlin, Heidelberg: Springer, pp. 271–309. https://doi.org/10.1007/3-540-32144-6_8
  34. Van Cappellen, P. and Qiu, L., 1997. Biogenic Silica Dissolution in Sediments of the Southern Ocean. II. Kinetics. Deep Sea Research Part II: Topical Studies in Oceanography, 44(5), pp. 1129–1149. https://doi.org/10.1016/s0967-0645(96)00112-9

Files

 Full text (English)

  JATS XML (English)

 Full text (Russian)

We use Yandex Metrics. Read more.

Мы используем Яндекс Метрику. Подробнее.