Dust Storms and their ecological impacts on Chlorophyll distributions over the Persian Gulf (1997-2007)

The Persian Gulf due to its position in subtropical belt is influenced by many intense dust storms during the year. The periodic dust events are expected to affect significantly the ecological condition of the Persian Gulf. The purpose of the present study was to investigate the impact of mineral dust on the primary production in phytoplankton communities of Persian Gulf. Satellite data from SeaWiFS sensor were used in order to analyze monthly mean aerosol optical thickness (AOT) and chlorophyll concentration (Chl_a) from 1998 to 2007. The results identified that the maximum of AOT is occurred in warm season with a peak in July. Annual changes in distribution of chlorophyll-a in almost in all areas were similar and were showed a decrease in chlorophyll content with increasing water temperature except in Southern regions. It showed that the presence of mineral dust in the warm seasons in the southern Persian Gulf plays a key role in phytoplankton growth according to the disadvantage of other physical factors. The numerous experiments were associated with an increase in the correlation coefficient between chlorophyll-a concentration and AOT when was considered a monthly delay, from 0.19 to 0.51. This behavior might be due to the time required for mineral dust deposition and its significant environmental effects.