Changing nutrient cycling in Lake Baikal, the world’s oldest lake

Swann, George E. A.; Panizzo, Virginia N.; Piccolroaz, Sebastiano; Pashley, Vanessa; Horstwood, Matthew; Roberts, Sarah; Vologina, Elena; Piotrowska, Natalia; Sturm, Michael; Zhdanov, Andre; Granin, Nikolay; Norman, Charlotte; McGowan, Suzanne; Mackay, Anson W.

Abstract

Copyright © 2020 the Author(s). Published by PNAS. Lake Baikal, lying in a rift zone in southeastern Siberia, is the world's oldest, deepest, and most voluminous lake that began to form over 30 million years ago. Cited as the "most outstanding example of a freshwater ecosystem" and designated a World Heritage Site in 1996 due to its high level of endemicity, the lake and its ecosystem have become increasingly threatened by both climate change and anthropogenic disturbance. Here, we present a record of nutrient cycling in the lake, derived from the silicon isotope composition of diatoms, which dominate aquatic primary productivity. Using historical records from the region, we assess the extent to which natural and anthropogenic factors have altered biogeochemical cycling in the lake over the last 2,000 y. We show that rates of nutrient supply from deep waters to the photic zone have dramatically increased since the mid-19th century in response to changing wind dynamics, reduced ice cover, and their associated impact on limnological processes in the lake. With stressors linked to untreated sewage and catchment development also now impacting the near-shore region of Lake Baikal, the resilience of the lake's highly endemic ecosystem to ongoing and future disturbance is increasingly uncertain.

Citation

Swann, G. E. A., Panizzo, V. N., Piccolroaz, S., Pashley, V., Horstwood, M., Roberts, S., Vologina, E., Piotrowska, N., Sturm, M., Zhdanov, A., Granin, N., Norman, C., McGowan, S., & Mackay, A. W. (2020). Changing nutrient cycling in Lake Baikal, the world’s oldest lake. Proceedings of the National Academy of Sciences, 117(44), 27211-27217. https://doi.org/10.1073/pnas.2013181117

• Journal Article Type: Article
• Acceptance Date: Sep 14, 2020
• Online Publication Date: Oct 19, 2020
• Publication Date: Nov 3, 2020
• Deposit Date: Sep 14, 2020
• Publicly Available Date: Apr 20, 2021
• Journal: Proceedings of the National Academy of Sciences
• Print ISSN: 0027-8424
• Electronic ISSN: 1091-6490
• Publisher: National Academy of Sciences
• Peer Reviewed: Peer Reviewed
• Volume: 117
• Issue: 44
• Pages: 27211-27217
• DOI: https://doi.org/10.1073/pnas.2013181117
• Keywords: Multidisciplinary
• Public URL: https://nottingham-repository.worktribe.com/output/4903721
• Publisher URL: https://www.pnas.org/content/early/2020/10/13/2013181117