Biological Evaluation Of Dalian Oil Spill Contaminated Area Using Double Fluorescence Labeling T-RFLP

In the years of 2010, an oil pipeline explosion occurred in Dalian, resulting in a 38-square-kilometers oil spill area and severe damages on local environments and marine biological resourses. Since the spilled oil was mainly crude oil, with features such as poor volatile, prolonged detain at sea and difficulty in degradation, so it would make a relative long-term impact on local ecological environments. Therefore, it is necessary to make a continuous evaluation on local biological damage.In this thesis, the community structure and diversity of the bacteria are used as biomarkers for pollution damage assessment. Seven sites were selected near Dalian new port and the sediment samples before and after the oil spill were analyzed, using an improved double fluorescence labeling T-RFLP technique, for a preliminary evaluation on biological damage in this area.Results obtained in this thesis included:1. A double fluorescence labeling T-RFLP technique was established and used in the analysis of microbial community structure for the first time. Compared with the conventional T-RFLP, the established double-labeled T-RFLP had advantages in good repeatability, double restriction fragment (T-RFs) information obtained in a single run, thus made the analysis more efficient and accurate.2. Analysis of the sediment samples before and after the oil spill demonstrated microbial community structure did change in the polluted marine area. Analysis on the numbers of T-RFs demonstrated three sites showed opposite change trends before and after the oil spill and might be related with the oil spill incident or their geographic location. Amogst them, Dalian Bay (s15) is the site that oil spill accident occurred; Changxing Island (s6) is located in Bohai Bay and the exchange capacity is relatively poor; Port Arthur Laotieshan (s3) is at the junction of yellow River and Bohai River and the exchange ability is relatively strong. Above results were further validated by the similarity and cluster analysis of the 7 selected sites. All of the 7 sites showed different degrees of changes in dominant bacteria strains and their percentages.