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Science Frontiers ONLINE No. 72: Nov-Dec 1990 |
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Baikal's deep secrets
Lake Baikal, in Siberia, requires many superlatives in its description. It is the deepest lake, 1637 meters; the oldest lake, 20-25 million years; and home to the richest array of lake life, both in terms of biomass and recorded species. There are found here 1550 species and variants of animals plus 1085 plants. Over 1000 of these species of life are found nowhere else. The sediments de-posited on the lake floor are of astounding thickness. Bedrock lies 7 kilometers below the lake surface in some spots. With a maximum depth of 1637 meters, we find by subtraction places where more than 5 kilometers of sediment have collected.
The diversity of Baikal's life is remarkable in itself, but there are two aspects of it that approach the anomalous: (1) Baikal's seals are 1000 kilometers of so from salt water. How did they get there and when? (2) Hydrothermal-vent communities have been discovered at a depth of about 400 meters in the northern part of the lake. These communities contain sponges, bacterial mats, snails, transparent shrimp, and fish; some of which are new to science. Baikal's thermal vents are the only ones known in freshwater lakes. Their rela tion to saltwater vent communities has not yet been explored. (Stewart, John Massey; "Baikal's Hidden Depths," New Scientist, p. 42, June 23, 1990. Also: Monastersky, R.; "Life Blooms on Floor of Deep Siberian Lake," Science News, 138:103, 1990.)
Comment. Despite its inland position, the suspicion develops that Baikal was connected to the oceans in recent geological times.