Bottom Bituminous Constructions and Biota Inhabiting Them According to Investigation of Lake Baikal with the Mir Submersible

The bottom and biota of Lake Baikal (near Gorevoi Utes cape) in the places of natural oil uploading were investigated in summer 2008. This study was carried out at a depth of 900 m by means of the Mir submers� ible (1). Bottom irregularities (bituminous construc� tions), places of gas ("torches") and oil ("droppers") uploading, and structures with the presence of gas hydrates were examined. These objects are densely inhabited by deepwater invertebrates. Microorgan� isms oxidizing hydrocarbons are obviously the basis of the food chains of these ecosystems. A brief survey of the literature on the appearance of oil in Baikal (2, 3) and data from investigation of oil gathered from water surface near Gorevoi Utes cape and bottom sediments lifted to the surface were pub� lished earlier (1, 3). The district was investigated by means of echolocation and with a lateral locator. In examining the data cited below, it is necessary to keep in mind that it was difficult to determine the location of the Mir apparatus. When it touched bottom, Mir stirred up the water with suspension, which compli� cated visibility around it. In an investigation of the bottom in 2007 near Gor� evoi Utes cape, a relief depression from 870 to 920 m deep was revealed. There was an isolated hill with a height of 10 m and diameter of 50 m in the center of the depression. The hill had "torches" on its margins