DEEP MICROBIAL REMINERALIZATION IN THE ROSS SEA: EVIDENCE FOR POC SOURCE AS MAIN ORGANIC FUEL OF BIOLOGICAL PUMP.

Carbon dioxide production rates (CDPR) of micro-organisms were monitored through their electron transport system (ETS) activity in thedeep Ross Sea. The depth-integrated CDPR amounted to 28,2 mg C m-2d-1in the depth range 100-1000 m. Comparing CDPR determinedin this study with that obtained by sediment traps in the Ross Sea resulted that about 63% of organic carbon remineralized by respirationderived from POC pool. Such evidence highlighted POC source as main organic fuel of biological pump in the Ross Sea.