Algal Nitrogen Fixation In The Northwestern Part Of The Arabian Gulf

Abstract

Nitrogen fixation and cell counts of blue-green algae and diatoms in the northwestern area of the Arabian Gulf were assayed during the (period, 7-20 November, 1984. Spatial variations indicated that the maximum rate of nitrogen fixation and count of blue-green algae were found in Qatari water. The minimum values, on the other hand, were observed at the area of oil pipe lines off Saudi Arabian coast. Blue-green algae were represented mainly by Trichodesmium spp. and Anabaeaa spp.. In Kuwaiti water, where diatoms dominated the phytoplank-ton, nitrogen fixation was of moderate values. Experiments on diurnal variation of nitrogen fixation were conducted. Fixation in the dark was only up to 15% of that measured during the day light time.