Nestled in the heart of Southern Siberia, Lake Baikal holds the title as the world's oldest and deepest freshwater lake. Its unique biodiversity is now under threat from climate warming.
Lake Baikal in Southern Siberia, one of the world's oldest and deepest freshwater lakes.
Image Wikimedia
Home to 20% of the planet's liquid freshwater, Lake Baikal stands as a colossus among lakes. Its ability to withstand changes has been called into question following recent analyses. Studies have illustrated a warming of the lake, leading to a reduced annual freeze duration. This phenomenon directly and indirectly impacts the living organisms within the lake, altering their interactions.
An increase in the biomass of algae and the count of some zooplankton species, favored by higher temperatures, contrasts with the stability or slight decline of cold-preferential endemic species. These variations affect the nutrient cycle within the lake, bearing significant ecological consequences.
An international team has also observed, through sediment analysis, that nutrient influx has significantly increased since the mid-19th century. This rise is linked to stronger winds, enhancing water mixing—a phenomenon likely caused by the decrease in ice cover and temperature rise.
Using a mathematical model has allowed the simulation of biological interactions and environmental modifications. This model reveals that the reduction in ice cover could eliminate the winter algae production peaks, traditionally seen beneath the lake's clear ice.
The concept of "regime shift" emerges from this study, suggesting an abrupt transition in the lake's ecological state to a new configuration. This notion underscores the possibility of sudden and difficult-to-reverse changes in ecosystems under the effect of global warming.
Lake Baikal is vast, containing 20% of the planet's liquid freshwater.
Image Wikimedia
Lake Baikal, with its rich endemic fauna, including the freshwater seal nerpa, reflects the direct and indirect effects of climate warming on its physical and biological systems. This ancient and biodiverse gem faces a potential ecological regime change, an alarm signal for all the ecosystems on our planet.