Comparison of Assimilative Capacity and Trophic Index for Various Parts of the Sevastopol Bay Water Area

E. E. Sovga1*, I. V. Mezentseva2, K. A. Slepchuk1

1 Marine Hydrophysical Institute of RAS, Sevastopol, Russia

2 Sevastopol Branch of the N. N. Zubov State Oceanographic Institute, Sevastopol, Russia

e-mail: esovga@mhi-ras.ru

Abstract

The ecological state of the marine shallow water ecosystem (the case of the Sevastopol Bay) is analyzed by the ratio of assimilative capacity and E-TRIX index depending on the anthropogenic load level for the whole bay ecosystem. As part of analysis, the eastern, central, western parts of the bay were distinguished as well as the Yuzhnaya Bay (southern part). Calculations of the assimilative capacity and E-TRIX index for ecosystems of different parts of the Sevastopol Bay were performed using the in situ data of inorganic nitrogen for the period 1998–2012 obtained from the MHI RAS oceanographic data bank. The paper compares values of ecosystem assimilative capacity calculated for inorganic nitrogen as a prevailing pollutant in municipal and storm wastewaters and E-TRIX trophic index of the sea ecosystem, with the technogenic load and biological process seasonality (warm and cold periods) of nutrient income taken into account. This allowed to properly distinguish water areas, which are most vulnerable in terms of formation of negative ecological events, up to disasters. According to the obtained data, such an area is that of the Yuzhnaya Bay. The second vulnerable water area is the eastern apex part of the Sevastopol bay exposed to the Chernaya River discharge. As the results showed, the situation worsens during winter and spring freshets due to increase in content of inorganic nitrogen forms in the Chernaya River runoff. The ecosystem of the western bay part adjoining the open sea is the safest in terms of nitrate nitrogen assimilative capacity, whereas the central part ecosystem appears to be the cleanest in terms of E-TRIX. The ecosystem most exposed to ecological risks in terms of both indices (assimilative capacity and E-TRIX) is that of the Yuzhnaya Bay (the southern part of the Sevastopol Bay). The observed imbalance of distribution of the calculated trophic index E-TRIX and assimilative capacity in different parts of the Sevastopol Bay is due to various nature of these quantities. The assimilative capacity of an ecosystem is defined by physical, chemical and biological processes given a dynamic removal of pollutants from the ecosystem, whereas E-TRIX is determined, in general, by seasonal variability of nutrient income into the ecosystem.

Keywords

Sevastopol Bay, ecosystem, self-purification ability, assimilation capacity, inorganic nitrogen, trophic index Е-TRIX, Chernaya River

Acknowledgments

The research is performed under State Order on topic “Coastal studies” and funded by the RFBR grant and under Project no. 18-45-920002 “Self-purification ability of the Sevastopol Bay area ecosystems depending on the antropogenic load level”.

For citation

Sovga, E.E., Mezentseva, I.V. and Slepchuk, K.A., 2020. 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, (3), pp. 63–76. doi:10.22449/2413-5577-2020-3-63-76 (in Russian).

DOI

10.22449/2413-5577-2020-3-63-76

References

  1. Simonov, A.I. and Ryabinin, A.I., eds., 1996. [Hydrometeorology and Hydrochemistry of Seas. Vol. 4. The Black Sea. Iss. 3. Modern State of the Black Sea Waters Pollution]. Sevastopol: ECOSI-Gidrofizika, 230 p. (in Russian).
  2. Lopukhin, A.S., Ovsyany, E.I., Romanov, A.S., Kovardakov, S.A., Bryanzeva, Yu., Rylkova, O.A., Gavrilova, N.A., Gubanov, V.V., Lopukhin, S.A. [et al.], 2007. Seasonal Peculiarities of Hydrologic-Hydrochemical Structure of Sevastopol Bay Water, Microplankton and Distribution of its Biochemical Components (the Black Sea, Observations of 2004 – 2005). In: MHI, 2007. Ekologicheskaya Bezopasnost' Pribrezhnykh i Shel'fovykh Zon i Kompleksnoe Ispol'zovanie Resursov Shel'fa [Ecological Safety of Coastal and Shelf Zones and Comprehensive Use of Shelf Resources]. Sevastopol: ECOSI-Gidrofizika. Iss. 15, pp. 74–109 (in Russian).
  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. Sovga, E.E., Mezentseva, I.V., Khmara, T.V. and Slepchuk, K.A., 2014. [On Prospects and Possibilities of Assessment of Self-Purification Ability of the Sevastopol Bay Water Area] In: MHI, 2014. Ekologicheskaya Bezopasnost' Pribrezhnykh i Shel'fovykh Zon i Kompleksnoe Ispol'zovanie Resursov Shel'fa [Ecological Safety of Coastal and Shelf Zones and Comprehensive Use of Shelf Resources]. Sevastopol: ECOSI-Gidrofizika. Iss. 28, pp. 153–164 (in Russian).
  5. Ovsyany, E.J., Romanov, A.S., Min'kovskaya, R.Ya., Krasnovid, I.I., Ozyumenko, B.A. and Zymbal, I.M., 2001. The Most Important Sources of Pollution for the Marine Environment of the Coastal Zone of Sevastopol. In: MHI, 2001. Ekologicheskaya Bezopasnost' Pribrezhnykh i Shel'fovykh Zon i Kompleksnoe Ispol'zovanie Resursov Shel'fa [Ecological Safety of Coastal and Shelf Zones and Comprehensive Use of Shelf Resources]. Sevastopol, ECOSI-Gidrofizika. Iss. 2, pp. 138–152 (in Russian).
  6. Ivanov, V.A., Mezentceva, I.V., Sovga, E.E., Slepchuk, K.A. and Khmara, T.V., 2015. Assessment Self-Purification Ability of the Sevastopol Bay Ecosystem in Relation to Inorganic Forms of Nitrogen. Processes in GeoMedia, (2), pp. 55–65 (in Russian).
  7. Sovga, E.E., Mezentseva, I.V. and Kotelyanets, E.A., 2017. 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, 28(4), pp. 38–51 (in Russian).
  8. Sovga, E.E., Mezentseva, I.V. and Kotelyanets, E.A., 2017. [Assessment of the Ecological State of the Sevastopol Bay Water Area in the Zone of Influence of the River Chernaya]. In: Sevastopol Branch of MSU, 2017. [Proceedings of the 1st International Ecological Forum in Crimea “Crimea is Ecological and Economical Region. Zone of Nospheric Development” 2017]. Sevastopol: Sevastopol Branch of MSU, pp. 236–240.
  9. Mezentsevа, I.V. and Sovga, E.E., 2019. Self-Purification Ability of the Ecosystem of the East Part of the Sevastopol Bay with Respect to Inorganic Nitrogen. Ecological Safety of Coastal and Shelf Zones of Sea, (1), pp. 71–77. doi:10.22449/2413-5577-2019-1-71-77 (in Russian).
  10. Sovga, E.E. and Mezentseva, I.V., 2019. Ecological Condition of the Central Paer of Secastopol Bay depending on the Anthropogenic Load Level. Ecological Safety of Coastal and Shelf Zones of Sea, (3), pp. 52–60. doi:10.22449/2413-5577-2019-3-52-60 (in Russian)
  11. Izrael, Yu.A. and Tsyban, A.V., 1989. Anthropogenic Ecology of the Ocean. Moscow: Gidrometeoizdat, 528 p. (in Russian)
  12. Vollenweider, R.A., Giovanardi, F., Montanari, G. and Rinaldi, A., 1998. Characterization of the Trophic Conditions of Marine Coastal Waters with Special Reference to the NW Adriatic Sea: Proposal for a Trophic Scale, Turbidity and Generalized Water Quality Index. Environmetrics, 9(3), pp. 329–357. doi:10.1002/(SICI)1099-095X(199805/06)9:3<329::AID-ENV308>3.0.CO;2-9
  13. Ivanov, V.A., Mikhailova, É.N., Repetin, L.N. and Shapiro, N.B., 2003. A Model of the Sevastopol'skaya Bay. Reproduction of the Vertical Structure of Temperature and Salinity Fields in 1997–1999. Physical Oceanography, (4), pp. 201–222. https://doi.org/10.1023/A:1025850016768
  14. Ivanov, V.A. and Tuchkovenko, Yu.S., 2006. Applied Mathematical Modelling of Water Quallity of Shelf Marine Ecosystems. Sevastopol: MHI, NAS of Ukraine, 368 p.
  15. Slepchuk, K.A., 2014. Modelling of Annual Phytoplankton and Biogenic Element Dynamics in the Sevastopol Bay Water Area Using an Optimization Method for Biogeochemical Model Calibration. In: MHI, 2014. Ekologicheskaya Bezopasnost' Pribrezhnykh i Shel'fovykh Zon i Kompleksnoe Ispol'zovanie Resursov Shel'fa [Ecological Safety of Coastal and Shelf Zones and Comprehensive Use of Shelf Resources]. Sevastopol, ECOSI-Gidrofizika. Iss. 28, pp. 231–236 (in Russian).
  16. Slepchuk, K.A., 2019. Estimation of Eutrophication Level of the Sevastopol Bay Areas Based on the Results of E-Trix Index Numerical Modelling. Processes in GeoMedia, (1), pp. 91–96 (in Russian).
  17. Slepchuk, K.A., Khmara, T.V. and Man’kovskaya E.V., 2017. Comparative Assessment of the Trophic Level of the Sevastopol and Yuzhnaya Bays Using E-TRIX Index. Physical Oceanography, (5), pp. 60–70. doi:10.22449/1573-160X-2017-5-60-70

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