Project II.2.3j: Characterizing communities - Drifter studies: Short term variation in bacterioplankton community composition an
Project Name: II.2.3j Characterizing communities - Drifter studies: Short term variation in bacterioplankton community composition and gene expression in the Columbia River plume and coastal ocean.
Project Lead: Byron Crump
Project Description
Our goal is to describe diel variability in total bacterioplankton community composition, active bacterioplankton composition, and bacterioplankton gene expression in the Columbia River plume and adjacent coastal ocean. The relative abundance and activity of bacterial populations within these communities change with time in all environments, but observations of these changes have focused on long time scales (monthly, seasonally) and we know very little about short-term variability in these communities. Bacterioplankton growth in coastal waters is rapid, but the doubling time of these communities is generally longer than 12 hours, suggesting that the taxonomic composition of these communities cannot change significantly on a diel cycle. However, cellular production/degradation of rRNA and mRNA can occur on much shorter time scales in response to environmental conditions. For example, organisms that use light energy may produce rRNA and mRNA for protein synthesis during the day but not at night. Describing hourly to daily variability in bacterioplankton community composition and gene expression will provide insight into community dynamics at the scale of the bacterial reproduction cycle.
Fit in program
We need to understand the scales of variability of bacterioplankton community composition in our study region, as foundation to begin addressing CMOP framing hypothesis and to consider modeling strategies.
Outcomes
We conducted four sampling series during the Wecoma cruise in July, 2008. Two were conducted in the Columbia River plume, during which the patch of water moved offshore and mixed with coastal ocean water. Two others were conducted at offshore locations on the Gray’s Harbor Line and Newport Hydroline, during which the patches of water remained relatively unchanged for the full 24 hours.
