Chlorophyll-a concentrations were measured as an indicator of primary productivity within the euphotic zone, covering standard sampling depths from the surface down to 200 m. In parallel, discrete water samples for phytoplankton community composition were collected at selected super-stations along extended environmental monitoring transects. During Leg 2.3, additional qualitative phytoplankton samples were obtained using a vertical net haul with a 10 µm mesh phytoplankton net deployed to a maximum depth of 30 m at selected stations. All net samples were preserved in 2% formaldehyde solution and stored in 250 mL polyethylene bottles for subsequent laboratory analysis.