IATROSCAN-MEASURED PARTICULATE AND DISSOLVED LIPIDS IN THE ALMERIA-ORAN FRONTAL SYSTEM (ALMOFRONT-1, MAY 1991)

The Chromarod-Iatroscan system was used to measure dissolved and parti culate lipids at six sites representative of the main hydrological zon es of the Almeria-Oran frontal system in May 1991. Concentrations rang ed from 9 to 113 mug l-1 and from 3 to 84 mug l-1 respectively. Partic ulate carbon was estimated on a CHN Leco analyzer. Dissolved lipid con centrations were highly variable with depth and exhibited clear signat ures of phytoplankton degradation throughout the profiles. In the 300- 400 m layer, particulate wax esters denoted the presence of deep zoopl ankton which may benefit from the downward fluxes of organic matter fr om the frontal zone. In surface water, high concentrations of dissolve d lipids and particulate carbon marked the presence of the jet front. Particulate lipid classes in samples were related to the presence of z ooplankton and to the physiological state of cells rather than to phyt oplankton biomass. Particulate triglyceride concentrations (storage li pids in phytoplankton) increased from the left to the right border of the jet core and further southwards, culminating in the Atlantic antic yclonic gyre. The distribution of particulate lipids to carbon and chl orophyllatios and the increasing level of triglycerides from the jet a nd southwards suggested a rapid removal of the frontal production by p hysical transports. The ability of anticyclonic structures to enhance accumulations of energetically rich compounds and thus to play a role as fertilizers of the oligotrophic waters of the Mediterranean Sea is discussed.