Dissolved Organic Carbon Dynamics in the Ligurian Sea

This chapter summarizes the present knowledge of dissolved organic carbon (DOC) dynamics in the Ligurian Sea, including a re-assessment of its stocks and fluxes on a basin scale. The DOC data, collected monthly at the DYFAMED station in the years 1991–1994, represent a unique opportunity to investigate DOC seasonal cycles in the Ligurian Sea. Focusing on the surface layer (5 m), the horizontal distribution of DOC shows high spatial variability in both May and September 2003, and was clearly affected by the upwelling and chlorophyll distribution. Daily variation in DOC concentration and composition was also investigated at the DYFAMED station in March and June 2003. No changes in DOC concentration were observed between day and night, whereas chromophoric dissolved organic matter absorbance increased during the day and biogenic dissolved lipids accumulated at night, suggesting a change in dissolved organic matter composition.