MICROBIAL ACTIVITY IN THE SEDIMENT OF THE SOGNEFJORD (NORWAY)

The activity of microorganisms was investigated in sediment samples of the Norwegian Sognefjord at a 1260 m depth. The enzymatic potential ( measured, using the cleavage of fluoresceindiacetate FDA) ranged betwe en 11 and 29 nmol FDA cm(-3) h(-1). Labeled Anacystis sp. (Cyanobacter ia) were degraded (measured as Liberation of C-14-labeled CO2) at a ra te of 0.67-1.24 % day(-1). The assays were run at 1 atm and at 126 atm pressure. In both cases, activity was higher when samples were incuba ted under 1 atm than under simulated in-situ conditions. This indicate s that the sediment community of the fjord is adapted only to a limite d extent to the elevated pressure at the bottom. The results are compa red and discussed with data from other deep marine environments.