New operative methods to study pelagic ecosystem

The study of the physical and trophic processes in marine ecosystems requires methods that consider time and space scale of the fluctuation of oceanographic phenomena. In order to answer to necessity of quasi-synoptic observations, during the last years, we have developed a number of towed vehicles. Particularly, the Sarago last version was tested in several oceanographic cruises and since 1996 its instrumental payload included a new double impulse fluorometer to estimate phytoplankton productivity (based on the approach pioneered by Falkowski & Kolberg, 1993). The vehicle was fully capable of investigating various phenomena at different time and space scale, from the cyclonic gyre to the river plumes. During 1998 we have developed a new undulating towed vehicle and till today a new modular vehicle is going to be assembled. Preliminary results of developed systems will be discussed in the present paper.