Towards an impact assessment of bauxite red mud waste on the knowledge of the structure and functions of bathyal ecosystems: The example of the Cassidaigne canyon (north-western Mediterranean Sea)

摘要: Since 1967, the alumina plants in Marseilles area (Barasse and Gardanne) have been discharging mineral residue (i.e., red mud) resulting from alkaline processing of bauxite into submarine Cassidaigne canyon (north-western Mediterranean Sea) through pipes situated at 320-330 m depth. The Barasse pipe stopped being used 1988. From 1987 to 1996, many decrees regulations were promulgated by French State rule conditions under which Gardanne refinery was authorized dispose sea. required: (i) study hydrodynamic circulation evaluate potential dispersion transport fine elements discharged water mass their impact on pelagic ecosystem; (ii) survey marine environment every five years control expansion thickness mud deposit compare evolution benthic macrofauna representative sampling sites affected discharge with that reference outside plume; (iii) effect fishing activities; (iv) investigate toxicity mud, particularly its persistence, accumulation, interaction ecosystem, paying special attention bio-accumulation chromium vanadium. A Scientific Committee created insure an independent evaluation studies promised manufacturer response State's regulations. beginning 1960s, data accumulating structure long-term functioning bathyal ecosystem. This paper presents collaborative efforts State-Manufacturer-Committee triplet summarizes main results obtained during last period's sea campaigns (1991-2007). also illustrates how national concerning manufacturers, such as refinery, provided new knowledge about a ecosystem north-western Sea.