BIOGEOCHEMISTRY OF HYDROTHERMAL ECOSYSTEMS OF THE MANUS AND LAU BASINS

The rates of the main biochemical processes of the carbon cycle (CO2 a ssimilation and CH4 oxidation) in the region of active hydrothermal fi elds of the Manus and Lau basins were determined quantitatively. The r ate of dark CO2 assimilation in the 350-meter layer of the seafloor wa ter on the testing grounds of the Manus and Lau Eastern basin varied f rom 1.2 to 2.5 mu g C/liter/day, while the intensity of methane oxidat ion was no more than 1.3 mu g C/liter/day. The results of these invest igations made it possible to calculate the C-org flow formed in bacter ial chemosynthesis. This flow in the region of the ''Viennese Wood'' i n the Manus basin measures 2.7 kg/day, which is comparable with the ma ss of the C-org flow from the photic zone (6.8 kg/day).