Biomass and production characteristics of the first red tide noticed in Kuwait Bay, Arabian Gulf

Observations on the first red tide off Kuwait, Arabian Gulf, yielded high b iomass [55.4-262.7 mu g chlorophyll (Chl) a l(-1)] and primary production ( 507.9-571.2 mu g C h(-1) l(-1)), comparable with some of the highest values reported. There were contrasting changes in the carbon assimilation ratios , composition of the phytoplankton and the contribution of nanoplankton (<2 0 mu m) between 11 and 12 May. On 11 May, carbon assimilation by nanoplankt on was 2.2 mu g C (pg Chl a)(-1) h(-1), but increased to 9.2 mu g C (mu g C hl a)(-1) h(-1) the following day. Nanoplankton contributed 56 and 9% of Ch l a and production, respectively, on 11 May, while net plankton (>20 mu m) accounted for >65% of the biomass and primary production on 12 May. Picopla nkton (<3 mu m) contributed <8% of Chl a and <3% of production. Frequent sa mpling will be necessary to capture such dynamic changes and ephemeral even ts in these waters.