Inhibition Effect Of Four Oil Dispersants On Primary Productivity In Qatar Water (Ararian Gulf)

Abstract

Four major oil dispersant mixtures in seawater wore used to depict their in—situ inhibition ratio to productivity rate of natural phytophanklon populations in Qatar water — Arabian Gulf — during the spring season of 1986. Results revealed that the highest gross production rate was attained in March (82 mg C m h ), while the highest net production rate Was in February (56 ing C in"3 h~'). The ratios between the net and gross production-rates were 83.60%. 57.30% and 38.95% for the monlhs of February, March and April respectively. The 50% relative inhibition in gross production rate due to dispersant mixtures ranged between 73-450 ppm and their threshold inhibition effect appeared between 2—57 ppm indicating their adverse effect on the marine ecosystem if misused or misplaced away from the slick area.