Congratulations to Joanna Zhang recipient of the 2010 Ruth Patrick Science and Education Center Environmental Science Award at the 2010 Central Savannah River Area Science and Engineering Fair.
Joanna is an 11th grader at Lakeside High School.
Title of project
Archaeal community composition in the Yangtze River along the Three Gorges Dam
Joanna evaluating samples she obtained from Yangtze River.
Rivers are important in the movement of nutrients, minerals, and organic matter from land to oceans. However, dams can disrupt the natural flow of surface waters and can affect the nutrient or biological composition of the rivers, for example, due to the sedimentation of phosphate or silicate before the dam. The Three Gorges Dam is the largest dam in China, located on the Yangtze River in the Hubei Province. At present, its impact on the river ecosystem and water biogeochemistry is unknown. In this study, sediment particles were collected on filters (0.7 m diameter) from above and below the dam for the construction of archaeal clone libraries to evaluate whether the archaeal community structures change due to the stagnation of water above the dam. Total genomic DNA was extracted and the archaeal 16S ribosomal RNA genes were amplified and sequenced. The results revealed similar diversity of archaea (1.95-2.23) from above and below the dam. The composition of the archaeal community was primarily of group I.1a, I.1b and I.3b of crenarchaeota above and below the dam. Statistically, the overall archaeal community structure is indifferent. Analyses of phosphate, silicate, and nitrate in the river water were performed in a later sampling date and the results showed no significant difference above and below the dam. I plan to go back to China to sample again to further evaluate the stability of microbial community structure along the Three Gorges Dam.