Is a High Abundance of Spring Diatoms in the Photic Zone of Lake Baikal in July 2019 Due to an Upwelling Event?
Mikhail Grachev,
Yurij Bukin,
Vadim Blinov,
Oleg Khlystov,
Alena Firsova,
Maria Bashenkhaeva,
Oxana Kamshilo,
Lubov Titova,
Elvira Bairamova,
Yekaterina Bedoshvili,
Maria Sakirko,
Yulia Zakharova
Affiliations
Mikhail Grachev
Laboratories of Genosystematics and Hydrophysics, Department of Cell Ultrastructure, Limnological Institute, Siberian Branch of the Russian Academy of Sciences, 664033 Irkutsk, Russia
Yurij Bukin
Laboratories of Genosystematics and Hydrophysics, Department of Cell Ultrastructure, Limnological Institute, Siberian Branch of the Russian Academy of Sciences, 664033 Irkutsk, Russia
Vadim Blinov
Laboratories of Genosystematics and Hydrophysics, Department of Cell Ultrastructure, Limnological Institute, Siberian Branch of the Russian Academy of Sciences, 664033 Irkutsk, Russia
Oleg Khlystov
Laboratories of Genosystematics and Hydrophysics, Department of Cell Ultrastructure, Limnological Institute, Siberian Branch of the Russian Academy of Sciences, 664033 Irkutsk, Russia
Alena Firsova
Laboratories of Genosystematics and Hydrophysics, Department of Cell Ultrastructure, Limnological Institute, Siberian Branch of the Russian Academy of Sciences, 664033 Irkutsk, Russia
Maria Bashenkhaeva
Laboratories of Genosystematics and Hydrophysics, Department of Cell Ultrastructure, Limnological Institute, Siberian Branch of the Russian Academy of Sciences, 664033 Irkutsk, Russia
Oxana Kamshilo
Laboratories of Genosystematics and Hydrophysics, Department of Cell Ultrastructure, Limnological Institute, Siberian Branch of the Russian Academy of Sciences, 664033 Irkutsk, Russia
Lubov Titova
Laboratories of Genosystematics and Hydrophysics, Department of Cell Ultrastructure, Limnological Institute, Siberian Branch of the Russian Academy of Sciences, 664033 Irkutsk, Russia
Elvira Bairamova
Laboratories of Genosystematics and Hydrophysics, Department of Cell Ultrastructure, Limnological Institute, Siberian Branch of the Russian Academy of Sciences, 664033 Irkutsk, Russia
Yekaterina Bedoshvili
Laboratories of Genosystematics and Hydrophysics, Department of Cell Ultrastructure, Limnological Institute, Siberian Branch of the Russian Academy of Sciences, 664033 Irkutsk, Russia
Maria Sakirko
Laboratories of Genosystematics and Hydrophysics, Department of Cell Ultrastructure, Limnological Institute, Siberian Branch of the Russian Academy of Sciences, 664033 Irkutsk, Russia
Yulia Zakharova
Laboratories of Genosystematics and Hydrophysics, Department of Cell Ultrastructure, Limnological Institute, Siberian Branch of the Russian Academy of Sciences, 664033 Irkutsk, Russia
A high abundance of planktonic microalgae is typically thought to be related to their ‘bloom’, that is, to active population growth. Diatom blooms in the photic zone of Lake Baikal generally occur during hydrological spring (April–June); when the summer arrives and the surface water temperature increases, diatoms are replaced by other microalgae. In July 2019, we found a concentration of the diatom Fragilaria radians at a station in South Baikal that was extremely high for that season. This species generally blooms in spring, but in spring (May) of 2019, this alga was nearly absent from the phytoplankton population. Microscopic analysis of the sample taken in July 2019 revealed that the cells were in a dormant stage. The species composition of microalgae in phytoplankton samples from May 2018 and July 2019 was similar. According to the temperature profile analysis, a summer upwelling event from a depth of ca. 100 m occurred in 2019. We hypothesised that this event caused the resuspension of microalgae, including Fragilaria radians, which were deposited on the slopes of the lake in 2018. Hence, the high abundance is not always a ‘bloom’ or an active growth.
