Bacteriological Study Of The Waters Of Bohai Bay In Tianjin

The investigation of the bacteria abundance in the water surface of costal Bohai Bay-Tianjin zone were carried out from July, 2003 to May, 2004. The results show that the bacterioplankton in seawater sample of the studied coastal area was obviously more abundant than that in outer sea and the sewage from Haihe river has made great effect on the quality of that waters. The maximum value of AODC(total bacteria), DVC(direct viable count) and HPC (heterotrophic plate count) reached 1.92×107cells/mL, 1.22×107 cells/mL and 4.95×104 cfu/mL during the four cruises. The maximum value of E.coli group bacteria and pathogenic vibrio, bacteria reached to >11000cells/L and 67cfu/mL during the winter and spring cruises. During the spring cruise, the abundance of petrolium degradating bacteria ranged from 4300 to 110000 cells/L. In addition, the distribution of bacteria was mostly determined by the distance to the shore and the estuary . Sites near the estuary had the largest bacteria number in winter due to the effect of the effluent of Haihe river. E.coli group bacteria and vibrio were detected in most sites. In addition, the abundance of petrolium degradating bacteria is increasing in recent years. Moreover, there were significant correlations between the value of AODC, DVC, HPC and E.coli group bacteria in a same sample.