The 24h LC50 values of Penaeus monodon Fabricius, Xiphophorus helleri, Macrobrachium rosenbergii and Ctenogobius gymnachen are respectively 14. 9, 1 725. 0,2 238. 0 and 5 861. 0 mg' L-1, and their sensitivities to oil dispersant are from high to low in the order of Penaeus monodon Fabricius, Xiphophorus helleri, Macrobrachium rosendergii and Ctenogobius gymnachen.
The results showed that 96h LC 50 values of bore mud were over 10 5 mg/L, and that of three types of oil dispersants were 1 047 mg/L, 5 011 mg/L and 2 630 mg/L respectively.
The results show that 96hLC 50 values of three kinds of oil drilling mud are over 10 5 mg/L and that of three brands of oil dispersants are 1 258mg/L, 4 469mg/L and 2 545mg/L respectively.
Now the oil platform W12-1A is implement Oil Overflow Meet An Emergency Plan of Weizhou Oilfield which written in 1998. The on watch boat Nanhai 203 never equiped Oil Spill Chemical Dispersants GMS-2 for 20 barrels and never equiped 9-meters long Oil Spill Chemical Dispersants insufflation pipe.
Chemically dispersed fuel oil was only slightly more toxic than mechanically dispersed fuel oil; an additive, rather than synergistic, effect of oil/dispersant mixture was found.