Research On The Effect Of Nitrobenzene Pollution To The Plankton In Songhua River

Nitrobenzene is often detected in the large or medium sized rivers of China. It is harmful to the beings in nature. The reports about the effect of nitrobenzene to beings in the past commonly came from the researches in the laboratories with high effect concentration. The researches on the effect of nitrobenzene to the ecosystem in nature are few. During December 4, 2005 and December 19, 2005 the effects of the nitrobenzene pollution to the community structure of the phytoplankton and zooplankton was investigated through the methods of taking samples at the four sections in the Jiamusi reach of the Songhua River, identifying species and analyzing datum in this paper.The results indicate, 114 species of floating algae belong to 8 phyla, 54 genera, and 46 species of the zooplankton belong to 24 genera, which were identified altogether before and after the nitrobenzene water mass going through the Jiamusi reach. Because of the high cell density, dominant species were not changed by the pollution. Some species dismissed and the other appeared at the four sections after the contaminative water mass going through the Jiamusi reach, but the species in Sifengshan reservoir were not changed like that, so the pollution had some effect on the community structure of the plankton. After the pollution, the cell density of the plankton had a great decrease (p<0.05) in the Jiamusi reach. The effective degree of nitrobenzene to the decrease of the cell density was about 25%. The diversity of the plankton community also changed with the variety of the community structure.It is the first time the effect of low concentration nitrobenzene (about 0.165 mg/L ~0.343mg/L) to the community structure of phytoplankton and zooplankton was studied in our country. It may provide bases to the researches on the effect of nitrobenzene to the ecosystem and to the renovation of water quality in the Jiamusi reach.