Toxic Effects Of Crude Oil On The Amphipoda Crandidierella Japonica

Grandidierella japonica, being to Arthropoda, was selected to as the testing organism for analyzing the acute and chronic damages of spilled oil on sea and marine organisms. The effects of heavy and light oil Water-soluble fractions(WAF) on survival of G. japonica individual and activity of biomarkers Malondialdehyde(MDA), Reduced glutathione(GSH), Glutathione peroxidase(GSH-Px), and Glutathione S-transferase(GST) were studied. The results were analyzed and assessed basing on the integrated biomarker responses.The results of 96 h acute toxicity test: increasing concentration of heavy and light oil WSF versus increasing mortalities of G. japonica individual at 24, 48, 72, 96 testing hours. The half lethal concentration of heavy and light oil WSF are 1.74mg·L-1 and 2.09 mg·L-1, respectively.The results of 7d chronic toxicity test: different level effects of heavy and light oil WSF on 5 biomarkers of G. japonica in vivo.MDA content increased in accordance with the increase of heavy oil WSF concentrations. Compared with MDA content in the control group, there was no significant difference in the lowest concentration group(p>0.05), while there was a highly obvious difference in two high concentration group(p<0.01). Exposure to light oil WSF, MDA content showed a climb up and then decline u- typed trend. Maximum value of MDA content appeared in the group of 121μg·L-1, and there was a highly significant difference compared with the control group(p<0.01). MDA content began to descend from the group of 363μg·L-1 to 1087μg·L-1and there was a significant(p<0.05) and highly significant difference(p<0.01) compared with the control group. The highest concentration group, MDA content had no significant difference to the comparison.The contents of GSH of G. japonica, in four test groups, increased at first and then descended with the increasing concentration of heavy oil WSF, but had a less decrease as compared with the control group(p<0.05). Similarly, they have a same trend in all of light oil WSF test groups. The highest value of GSH content had a highly significant difference to the control in the group of 121μg·L-1(p<0.01). While had a significant difference and no significant difference in the group of 363μg·L-1(p<0.01) and in the group of 121μg·L-1(p>0.05), respectively.The activity of GST enzyme increased firstly and then descended with the increasing concentration of heavy oil WSF. Maximum was found in the group of 96μg·L-1. All of groups had a highly significant difference to the comparison(p<0.01). For the light oil exposed testing, The GST enzyme activity was significantly lower than the control in low-concentration group(p<0.01), was significantly higher in middle-concentration groups(p<0.05), was no difference in high-concentration group(p>0.05).The activity of GSH-Px enzyme shown a climb up then declined trend, and influenced by the increasing concentration of heavy oil WSF. Compared with the control group, the activity of GSH-Px enzyme was obviously low in group of 24μg·L-1 and 382μg·L-1, while there was obviously high between other groups. In the test of light oil WSF, GSH-Px activity opposite to the test of heavy oil WSF.In all of heavy oil WSF tests, DPC content all had obviously difference compared to the control(p<0.01). Maximum of DPC content was founded in the medium content group of 96 μg·L-1, which had a significant difference between others. In terms of light oil WSF test, DPC contents of all groups for the comparison had a obvious difference(p<0.01). In the group of 121 μg·L-1, the DPC content was the highest in all groups, and except there was no significant difference with the group of 3261 μg·L-1(p>0.05), significant difference with the rest of groups(p<0.05).The integrated biomarker responses(IBR) was utilized to analyze initially and evaluate quantificationally for the toxic effects of heavy and light oil WSF on G. japonica. The IBR values, in the all groups, were increased before decreased and then increased as increasing the heavy and light oil concentration. And had obviously differences to the comparison(p<0.01). More high concentration oil WSF compacted more seriously effect on G. japonica. In the five biomarkers, MDA and GSH made small contribution for the value of IBR, while GST、GSH-Px and DPC made big. So, GST、GSH-Px and DPC shown a high sensitivity in the chronic toxicity testing.