Lake Van: The World’s Largest Soda Lake and Its Surrounding Lakes
Lake Van (Figs 1-2), located at an average altitude of 1,646 meters in the highlands of Eastern Anatolia, Turkey, is the world’s largest soda lake. Approximately 600,000 years ago, lava flows from Mount Nemrut blocked the path of the Murat River, forming this enclosed basin. Today, Lake Van covers an area of 3,764 square kilometres and has a volume of 607 km³, with a unique chemical composition. Shaded by the surrounding high mountains, the lake has an average depth of 171 meters, with its deepest known point reaching 451 meters. Due to its high sodium carbonate content and other alkaline, the lake’s water has exceptionally high alkalinity, with an average pH level between 8.5 and 9.5. This characteristic makes Lake Van extremely rich in microbial life, particularly in diatom diversity.
Despite the importance of this vast ecosystem, Lake Van’s diatom flora remains relatively unexplored. Approximately 80 years ago, Legler & Krasske (1940) conducted pioneering research on the lake, describing 24 diatom taxa. Building on this foundational work, I began studying Lake Van for my doctoral thesis four years ago, during which time we identified four species from the genera Navicula, Halamphora, and Craticula. Navicula vanseea (Fig. 3) has already been published (Yilmaz et al. 2024). Our research is based on single-cell isolation studies, allowing us to closely examine the diverse diatoms present in this highly alkaline environment. Currently, under a new project, we are expanding our work to include Lake Van and other nearby lakes. One of these lakes, the largest second crater lake in the world – Lake Nemrut (Fig. 4), adds significant value to our comparative studies.
Our central hypothesis is as follows: Were Lake Van and the surrounding lakes once part of the same body of water, or did they form as separate ecosystems over time? In line with this hypothesis, we collected diatom samples in September 2024 and began single-cell studies. These efforts focus on analyzing the genetic and morphological characteristics of diatoms from Lake Van and the surrounding lakes. Based on these taxonomic and molecular studies, we aim to determine whether these lakes once shared a common aquatic environment or developed as distinct ecosystems. We believe that this research will provide valuable insights into the evolutionary processes that shape life in extreme habitats, contributing to a deeper understanding of diatom biodiversity and the geological history of the region.
Figure 1. Lake Van
Figure 2. Lake Van
Figure 3. Navicula vanseea Yilmaz, Gastineau, Solak & Witkowski 2024
Figure 4. Lake Nemrut
REFERENCES
Legler, F., & Krasske, G. (1940). Diatomeen aus dem Vansee (Armenien). Beiträge zur ökologie der brackwasserdiatomeen I. Beihefte zum Botanischen Centralblatt, 60, 335-345.
Yılmaz, E., Mann, D. G., Gastineau, R., Trobajo, R., Solak, C. N., Górecka, E., Turmel, M., Lemieux, C., Ertorun, N. & Witkowski, A. (2024). Description of Navicula vanseea sp. nov. (Naviculales, Naviculaceae), a new species of diatom from the highly alkaline Lake Van (Republic of Türkiye) with complete characterisation of its organellar genomes and multigene phylogeny. PhytoKeys, 241, 27. Doi: 10.3897/phytokeys.241.118903
I am Elif Yılmaz, a PhD candidate with a deep admiration for diatoms and their remarkable adaptations to extreme environments from the University of Szczecin. My supervisors are Prof. David G. Mann, and Dr. Romain Gastineau. My academic journey has centred around the taxonomy, ecology, and molecular biology of diatoms, allowing me to focus on the unique ecosystem of Lake Van and its surrounding lakes. My research explores the biodiversity of diatom communities in this highly alkaline environment. Having recently completed and submitted my thesis, I am eagerly looking forward to the next stage of my career and am actively seeking postdoctoral opportunities to continue advancing my expertise in diatom research and expand into new areas of ecological and molecular studies.