Primary productivity and nitrogen fixation by Trichodesmium spp. in the Arabian Sea

►This is a first study on the seasonal variation of Trichodesmium spp. in the Arabian Sea.►Trichodesmium thiebautii blooms at low temperature whereas Trichodesmium erythraeum at high temperature. ►T. spp. blooms synthesize 0.263 TgCyear− 1 and fix 0.2976 TgNyear− 1.