부산대학교 도서관

Rates of carbon dioxide assimilation and methane oxidation were determined in various zones of the Rainbow Hydrothermal Field (36°N) of the Mid-Atlantic Ridge. In the plume above the hydrothermal field, anomalously high methane content was recorded, the microbial population density (up to 10 cells/ml) was an order of magnitude higher than the background values, and the CO2 assimilation rate varied from 0.01 to 1.1 μg C/(l day). Based on the data on CO2 assimilation, the production of organic carbon due to bacterial chemosynthesis in the plume was calculated to be 930 kg/day or 340 tons/year (about 29% of the organic carbon production in the photic zone). In the black smoke above active smokers, the microbial population density was as high as 10 cells/ml, the rate of CO2 assimilation made up 5–10 μg C/(l day), the methane oxidation rate varied from 0.15 to 12.7 μl/(l day), and the methane concentration ranged from 1.05 to 70.6 μl/l. In bottom sediments enriched with sulfides, the rate of CO2 assimilation was at least an order of magnitude higher than in oxidized metal-bearing sediments. At the base of an active construction, whitish sediment was found, which was characterized by a high methane content (92 μl/dm) and a high rate of methane oxidation (1.7 μl/(dm day)).