Trichodesmium and other planktonic cyanobacteria in New Caledonian waters (SW tropical Pacific) during an El Niño episode

Contributions of filamentous and picoplanktonic cyanobacteria to the 26 phytoplankton community structure were examined in New Caledonian waters during the 2001-27 2003 El Nino period at three stations. Morphometric characteristics of diazotrophic filamentous 28 cyanobacteria are given as well as the seasonal and inter-annual variations of their surface areas 29 and integrated abundances. Trichodesmium tenue and T. thiebautii were the dominant species 30 followed by T. erythraeum, altogether accounting for more than 51-80 % of the biomass of the 31 free-living filamentous cyanobacteria. Katagnymene spp. accounted for a smaller percentage 32 (<13.8 % at ocean stations, <3.6 % in the lagoon). R. intracellularis biomass was relatively small 33 (<1 % of total surface area and volume of Trichodesmium trichomes) with the highest 34