Project II.2.3i: Characterizing communities - Microbiology in ETM
Project Name: II.2.3i Characterizing communities - Microbiology in ETM
Project Leads: Lydie Herfort and Peter Zuber
Project Description
Our goal is to describe temporal variations in microbial eukaryotic, bacterial and archaeal assemblages, and the gene expression therein, throughout a spring tide estuarine turbidity maxima (ETM) event in the South Channel of the Columbia river estuary. We also plan to compare spring tide ETM induced variations in bacterial assemblages in North and South channels as well as the year-to-year variability in the South channel. The ETM bacterial community will also be compared to that living in the surface sediments.
Fit in program
ETM is one of the most important events occurring in the estuary of the Columbia River because it is a site of terrestrial and marine organic matter accumulation and heightened microbial activity. These regions are populated by a unique bacterial community as measured with by sequence analysis of SSU DNA. To date, no detailed, molecular genetic-based characterization of the bacterial assemblage has been carried out on samples collected throughout an ETM re-suspension event. Similarly, no comparisons have been made between North and South Channel ETM bacterial assemblages, their activities and the composition of their populations. Our study will improve our understanding of the impact of ETM events on microbial communities in the estuary.
Outcomes
Bottom water was collected in the estuary before, during and after a spring tide ETM event in North and South channel in August 2007, and in South channel in July 2008. Surface sediments were also collected at 2 sites in North and South Channels in August 2007. Microbial eukaryotic, bacterial and archaeal assemblages will be characterized by SSU rRNA sequence analyses (cloning), microscope cell counts, and bacterial production rates. Gene expression will be determined by microarray analysis. Variation in assemblages and gene expression will be related to a suite of biological, physical and chemical parameters that were also measured.
