ORGANIC INPUT AND TRANSFORMATION AT THE WATER-SEDIMENT INTERFACE OF THE NW MEDITERRANEAN SLOPE (GULF OF LIONS)

Near-bottom fluxes of organic matter were studied in the northwestern Mediterranean continental slope (sediment traps were deployed at a dep th of about 1000 m in two canyons and one open slope). We found that f luxes of organic matter increase from the east to the west and were su bjected to seasonal variations. Near-bottom organic material being dif ferent from that of the upper deposits, the geochemical and biological responses of sediment interfaces were studied at the same time and lo cations. The results emphasize the need for direct evaluations of the flux parameters at the SWI. For this purpose, an input of organic matt er was-simulated and followed over time in the different biotic and ab iotic compartments of the SWI.