V. I. Ryabushko*, S. V. Shchurov, N. P. Kovrigina, M. A. Popov
A.O. Kovalevsky Institute of Biology of the Southern Seas of RAS, Sevastopol, Russia
* e-mail: rabushko2006@yandex.ru
Abstract
The ecosystem of unique Lake Donuzlav has been under significant anthropogenic pressure over a long period. Therefore, to assess the long-term changes occurring in the lake, regular monitoring studies are required. In June and October 2018, complex hydrological, hydrochemical and hydrobiological studies were carried out in the lake water area. Temperature, salinity, pH, dissolved oxygen content, biochemical oxygen demand on the fifth day (BOD5), permanganate oxidizability, concentration of silicon, mineral and organic forms of nitrogen and phosphorus, abundance and biomass of phytoplankton were determined by standard methods. It is shown that the thermohaline structure of waters directly affects the distribution of hydrochemical and hydrobiological indicators. In shallow water, a low oxygen content was recorded due to significant heating and poor water exchange, but no oxygen deficiency was found. Mussel and oyster farms and sewage have a significant impact on the ecological state of the lake. Especially high values of BOD5, oxidizability, maximum concentrations of organic forms of nitrogen and phosphorus were noted in these places. It was found that the biomass of phytoplankton increases and the species diversity decreases with distance from the sea to the apex part of the lake. Potentially toxic alga Dinophisis sacculus is found in small quantities, which does not affect the nutritional value of the molluscs. To assess the long-term changes in the phytoplankton community and its food reserves, regular monitoring studies of Lake Donuzlav are required in different seasons.
Keywords
hydrological and hydrochemical structure, biogenic elements, phytoplankton, Lake Donuzlav, Crimea, Black Sea
Acknowledgments
The work was funded under state order AAAA-18-118021350003-6 of IBSS RAS “Research of control mechanisms for production processes in biotechnological complexes with the aim of developing scientific foundations for obtaining biologically active substances and technical products of marine genesis”.
For citation
Ryabushko, V.I., Shchurov, S.V., Kovrigina, N.P., and Popov, М.А., 2021. Hydrological, Hydrochemical and Hydrobiological Studies of Lake Donuzlav (Western Crimea, Black Sea) based on the Results of Expeditions in 2018. Ecological Safety of Coastal and Shelf Zones of Sea, (2), pp. 80–93. doi:10.22449/2413-5577-2021-2-80-93 (in Russian).
DOI
10.22449/2413-5577-2021-2-80-93
References
- Shulgina, E.F., 1966. [Changes in the Hydrochemical Regime of Lake Donuzlav after Connecting it to the Sea]. In: BHO, 1966. [Collection of Works of the Basin Hydrometeorological Observatory of the Black and Azov Seas]. Leningrad: Gidrometeoizdat, pp. 11–19 (in Russian).
- Nemirovsky, M.S. and Kovrigina, N.P., 2000. Dynamics of the Lake Donuzlav Waters. In: IBSS, 2000. Ekologiya Morya. Sevastopol: IBSS. Iss. 51, pp. 10–13 (in Russian).
- Kovrigina, N.P. and Nemirovsky, M.S., 1999. Hydrochemical Characteristic of the Lake Donuzlav Waters based on Data of 1990–1997. In: IBSS, 1999. Ekologiya Morya. Sevastopol: IBSS. Iss. 48, рр. 10–14 (in Russian).
- Zuev, G.V. and Boltachev, A.R., 1999. Influence of Underwater Quarrying of Sand on the Donuzlav Estuary Ecosystem. In: IBSS, 1999. Ekologiya Morya. Sevastopol: IBSS. Iss. 48, рр. 5–9 (in Russian).
- Sebakh, L.К., Petrenko, О.А., Zhugaylo, S.S. and Tsyntaryuk, Е.А., 2006. Influence of Industrial Exploitation of the Sand Deposits on the State of the Lake Donuzlav Ecosystem. In: B. N. Panov, ed., 2006. Current Problems of the Azov-Black Sea Basin Ecology. Proceedings of II International Conference. Kerch, YugNIRO, 26–27 June 2006. Kerch: YugNIRO Publishers, pp. 71–79 (in Russian).
- Kochergin, A.T., Zagayny, N.A. and Kriskevich, L.V., 2017. Variability of Hydro-meteorological Conditions in Donuzlav Lake (Crimea) in 2016. Trudy VNIRO, 166, рр. 151–158 (in Russian).
- Dyakov, N.N., Korshenko, A.N., Malchenko, Yu.A., Lipchenko, A.E., Zhilyaev, D.P. and Bobrova, S.A., 2018. Hydrological and Hydrochemical Conditions of the Crimean and Caucasus Shelf Zones in 2016–2017. In: I. M. Kabatchenko, ed., 2018. SOI Proceedings. Moscow: SOI. Iss. 219, рр. 66–87 (in Russian).
- Zhugaylo, S.S., Avdeeva, T.M., Pugach, M.N. and Adzhiumerov, E.N., 2018. Current State of Water Quality and Bottom Sediments in Lake Donuzlav. Aquatic Bioresources and Environment, 1(1), рр. 32–38. https://doi.org/10.47921/2619-1024_2018_1_1_32 (in Russian).
- Ivanyutin, N.M., 2019. Current Ecological State of Lake Donuzlav. Water and Ecology, (3), pp. 47–58. https://doi.org/10.23968/2305-3488.2019.24.3.47-58 (in Russian).
- Lyakh, A.M. and Bryantseva, Yu.V., 2001. Computer’s Program for the Calculation of Basic Phytoplankton Parameters. Ekologiya Morya, 58, pp. 87–90 (in Russian).
- Kholodov, V.I., Grintsov, V.A., Pirkova, A.V., Lisitskaia, E.V., Popov, M.A., Murina, V.V. and Bogdanova, T.A., 2009. Biodiversity and Environmental Aspects of the Development of Conkhioculture in Lake Donuzlav (based on Materials from the Expedition June 4–7, 2008). Fisheries of Ukraine, (5), pp. 36–37 (in Russian).