Organic Matter in Waters of the Russian Sector of the Caspian Sea

L. V. Degtyareva1,*, O. I. Bakun2, M. A. Ocheretniy1

1 Caspian Marine Scientific Research Center, Astrakhan, Russia

2 LLC LUKOIL-Nizhnevolzsknev, Astrakhan, Russia

* e-mail: kaspmniz@mail.ru

Abstract

The paper aims to analyse the results of long-term studies of dissolved and suspended organic matter content in the waters of the Northern Caspian and Middle Caspian in the Russian sector of the Caspian Sea. The paper analyses the main sources of input of organic matter, its seasonal and inter-annual variability, features of its spatial distribution and causes (allochthonous organic matter flow, production and destruction, water temperature, sea level changes, etc.) determining the spatial and temporal dynamics of organic matter content. The paper is written on the results of production environmental monitoring conducted at the licensed areas of LLC LUKOIL-Nizhnevolzhskneft in 2017–2021. The organic matter amount was estimated by organic carbon. The dissolved organic carbon concentration was found to vary from 0.10 to 9.30 mg/dm3 in the surface water layer and from 0.10 to 9.60 mg/dm3 in the bottom layer. The maximum enrichment of waters with dissolved organic matter was noted in the northern part of the water area. The concentration of suspended organic carbon in the surface water layer varied within 0.10–23.40 mg/dm3, whereas in the bottom water layer it ranged within 0.05–19.40 mg/dm3. The spatial distribution of suspended organic matter was characterized by seasonal shifts of the area with maximum concentrations northwards. The main factors affecting the organic matter content in water were water temperature, suspended matter concentration in water and hydrogen ion concentration. The level of dissolved and suspended organic matter has not changed in the last 20 years of studies. The dependence of dissolved and suspended organic matter concentrations on environment pH indicates the natural origin of the organic matter in the waters of the monitored sea area.

Keywords

Caspian Sea, productivity, organic matter, dissolved organic matter, suspended organic matter, allochthonous organic matter, autochthonous organic matter

For citation

Degtyareva, L.V., Bakun, O.I. and Ocheretniy, M.A., 2025. Organic Matter in the Waters of the Russian Sector of the Caspian Sea. Ecological Safety of Coastal and Shelf Zones of Sea, (1), pp. 112–123.

References

  1. Agatova, A.I., Lapina, N.M., Torgunova, N.I. and Kodryan, K.V., 2021. Organic Matter and its Transformation Rates in Different Barents Sea Ecosystems. In: A. P. Lisitsin, ed., 2021. The Barents Sea System. Moscow: Izdatelstvo GEOS, pp. 212–235. https://doi.org/10.29006/978-5-6045110-0-8 (in Russian).
  2. Gershanovich, D.E., Zinkovsky, A.B., Mordasova, N.V. and Sanina, L.V., 1990. [Suspended Matter, Phytoplankton, Chlorophyll in the Caspian Sea]. In: A. N. Kosarev, ed., 1990. [The Caspian Sea: The Structure and Dynamics of Waters]. Moscow: Nauka, pp. 49–61 (in Russian).
  3. Khachaturova, T.A., 1981. Suspended Matter of the Caspian Sea and its Biochemical Composition. Oceanology, 21(1), pp. 70–76.
  4. Salmanov, M.A., 1999. [Ecology and Biological Productivity of the Caspian Sea]. Baku: PITS Ismail, 398 p. (in Russian).
  5. Agatova, A.I., Kirpichev, K.B., Lapina, N.M., Luk'yanova, O.N., Sapozhnikov, V.V. and Torgunova, N.I., 2005. Organic Matter in the Caspian Sea. Oceanology, 45(6), pp. 795–804.
  6. Ohle, W., 1962. Der Stoffhaushalt der Seen als Grundlage einer Allgemeinen Stoffwechseldynamik der Gewässer. Kieler Meeresforschungen, 18(3), S. 107–120. URL: https://oceanrep.geomar.de/id/eprint/55674 [Zugriffsdatum: 22.01.2025].
  7. Agatova, A.I., Lapina, N.M. and Torgunova, N.I., 2008. Organic Matter of the North Atlantic. Oceanology. 48(2). pp. 182–195. https://doi.org/10.1134/S0001437008020045
  8. Lisitsyn, A.P., 1994. A Marginal Filter of the Oceans. Oceanology. 34(5), pp. 735–747 (in Russian).
  9. Lobkovskii, L.I., Levchenko, D.G., Leonov, A.V. and Ambrosimov, A.K., 2005. [Geoecological Portrait of the Caspian Sea Ecosystem]. In: C. C. Lappo, ed., 2005. Geoecological Monitoring of Marine Water Arias Containing Gas and Oil. Moscow: Nauka, 326 p. (in Russian).
  10. Agatova, A.I., Torgunova, N.I., Serebryanikova, E.A. and Dukhova, L.K., 2019. Space and Time Variations of Organic Matter in Caspian Sea Water. Water Resources, 46(1), pp. 76–86. https://doi.org/10.1134/S0097807819010020
  11. Abdusamadov, A.S., Abdurakhmanov, G.M., Dohtukaeva, A.M. and Dudurhanova, L.A., 2011. Contamination of the Shallow Coastal Zone and Desalinated Shelf West of the Caspian Sea and its Impact on Biota and Reproduction of Fish. The South of Russia: Ecology, Development. (2), pp. 37–62 (in Russian).
  12. Karygina, N.V., 2019. [On the Content, Distribution and Genesis of Hydrocarbons in the Waters of the Northern Caspian Sea]. In: D. V. Kashin, ed., 2019. [Problems of Preservation of the Caspian Ecosystem During Oil And Gas Fields Development: Proceedings of the 7th Scientific and Practical Conference with International Participation. Astrakhan, 18 October 2019]. Astrakhan, KaspNIRKH, pp. 83–88 (in Russian).
  13. Karygina, N.V., Popova, E.S., Lvova, O.A., Galley, E.V. and Yatsun, E.V., 2020. On Oil and Pesticide Pollution of the Lower Volga and the Northern Part of the Caspian Sea. In: IngSU, 2020. [Ecology and Nature Management: Proceedings of International Scientific and Practical Conference. Magas, 21–23 October 2020]. Nazran: OOO KEP, pp. 250–257 (in Russian).
  14. Ostrovskaya, E.V. and Umrikha, A.V., 2019. Oil Pollution of the North-Western Part of the Caspian Sea: Current State and Main Sources. In: V. M. Gruzinov, ed., 2019. Proceedings of N.N. Zubov State Oceanographic Institute. Moscow, pp. 209–220 (in Russian).
  15. Shipulin, S.V., 2021. [State of Aquatic Bioresources in the Volga-Caspian Basin and Measures for their Conservation under Oil Production Development]. In: D. V. Kashin, ed., 2019. [Problems of Preservation of the Caspian Ecosystem During Oil And Gas Fields Development: Proceedings of the 7th Scientific and Practical Conference with International Participation. Astrakhan, 22 October 2021]. Astrakhan, KaspNIRKH, pp. 306–309 (in Russian).
  16. Skopitsev, B.A. and Larionov, Yu.V., 1979. [Organic Matter in Suspensions of Some Lakes with Different Trophic Status]. Vodnye Resursy, (5), pp. 159–170 (in Russian).
  17. Ostrovskaya, O.V., Gavrilova, E.V. and Varnachkin, S.A., 2022. [Changes in the Hydrological and Hydrochemical Regime of the North Caspian Sea Under Changing Climate Conditions]. In: O. V. Ostrovskaya and L.V. Degtyareva, eds., 2022. [Proceedings of the International Scientific Conference “Climate Change in the Caspian Sea Area”. 27–28 October 2021]. Astrakhan: Izdatel Sorokin R.V., pp. 75–77 (in Russian).
  18. Agatova, A.I., Lapina, N.M., Torgunova, N.I. and Kirpichev, K.B., 2001. Biochemical Study of Brackish-Water Marine Ecosystems. Water Resources. 28(4). pp. 428–437. https://doi.org/10.1023/A:1010401907179
  19. Nemirovskaya, I.A. and Brekhovskikh, V.F., 2008. Origin of hydrocarbons in the particulate matter and bottom sediments of the northern shelf of the Caspian Sea. Oceanology, 48(1), pp. 43–53. https://doi.org/10.1134/S0001437008010062
  20. Zhirkov, I.A., 2010. [Biogeography and Bioecology of Benthos]. Moscow: T-vo Nauchnykh Izdaniy KMK, 453 p. (in Russian).
  21. Yablonskaya, E.A., 1975. [Long-Term Changes in the Biomass of Various Trophic Benthic Groups of the Northern Caspian]. Trudy VNIRO, CVIII, pp. 50–64 (in Russian).

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