This lake was expected to be among those most resistant to climate change, due to its huge volume and unique water circulation, but long-term data collection reveals that warming is taking place.
In their paper, the scientists detail the effects of climate change on Lake Baikal - from warming of its vast waters to reorganization of its microscopic food web - drawing on 60 years of research.
The scientific research effort survived the reign of Stalin, the fall of the Soviet Union, and other more regional social and financial upheavals.
Data collection continued through every season, in an environment where winter temperatures drop to minus 50 degrees Fahrenheit.
Lake Baikal in Russia's northern region of Siberia (Photo by
The data on Lake Baikal reveal "significant warming of surface waters and long-term changes in the food web of the world's largest, most ancient lake," write the researchers in their paper.
"The conclusions shown here for this enormous body of freshwater result from careful and repeated sampling over six decades," said Henry Gholz, program director for the National Science Foundation's National Center for Ecological Analysis and Synthesis based at the University of California, Santa Barbara.
He said, "Thanks to the dedication of local scientists, who were also keen observers, coupled with modern synthetic approaches, we can now visualize and appreciate the far-reaching changes occurring in this lake."
"Warming of this isolated but enormous lake is a clear signal that climate change has affected even the most remote corners of our planet," said study co-author ecologist Stephanie Hampton, who serves as deputy director of the National Center for Ecological Analysis and Synthesis.
Lake Baikal contains 20 percent of the world's fresh water, and it is large enough to hold all the water in North America's Great Lakes.
It is the world's deepest lake as well as its oldest. At 25 million years old, it predates the emergence of humans.
In 1996, the United Nations Educational, Scientific and Cultural Organization, UNESCO, declared Lake Baikal a World Heritage site because of its biological diversity.
At least 2,500 plant and animal species inhabit the lake. Most of these species, including the freshwater seal, are found nowhere else in the world.
"Our research relies on a 60 year data set, collected in Lake Baikal by three generations of a single family of Siberian scientists," said study co-author Marianne Moore, a biologist at Wellesley College in Massachusetts.
"In the 1940s, Mikhail Kozhov began collecting and analyzing water samples in anticipation that this lake could reveal much about how lakes in general function," said Moore.
"Ultimately, his daughter Olga Kozhova continued the program, followed by her daughter, who is also a co-author of today's paper, Lyubov Izmest'eva."
Ice on Lake Baikal (Photo by Lyubov Izmest'eva)
Moore, Hampton and Izmest'eva, along with three other scientists, report their results online today in the journal "Global Change Biology."
"Increases in water temperature (1.21°C since 1946), chlorophyll a (300 percent since 1979), and an influential group of zooplankton grazers (335 percent since 1946) have important implications for nutrient cycling and food web dynamics," they write.
The scientists conclude that the lake now joins other large lakes, including Lake Superior, Lake Tanganyika and Lake Tahoe, in showing warming trends. "But," they note, "temperature changes in Lake Baikal are particularly significant as a signal of long-term regional warming."
The research paper is the result of a collaboration involving six Siberian and American scientists, who were assisted by student translators from Wellesley College.
The paper's Russian contributors are Izmest'eva, director of the Scientific Research Institute of Biology, Irkutsk State University, Irkutsk, Russia, and Eugene Silow of the Scientific Research Institute of Biology at Irkutsk State University.
Other U.S. contributers are Stephen L. Katz, recently of the Northwest Fisheries Science Center, NOAA Fisheries, Seattle, Washington, and Brian Dennis of the departments of statistics and fish and wildlife resources, University of Idaho, Moscow, Idaho.
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