Carr, L. M. University of Southern California, liamcarr@usc.edu
Ouverney, C. M. University of Southern California, ouverney@usc.edu
Fuhrman, J. A. University of Southern California, fuhrman@usc.edu

 
COMPARISON OF BACTERIAL AND ARCHAEAL CONCENTRATIONS BETWEEN NEAR-SHORE AND OPEN-OCEAN DEPTH PROFILES OFF SOUTHERN CALIFORNIA
 
The use of 16S RNA epifluorescent oligonucleotide probes has become increasingly prevalent for in situ characterization of natural bacterioplankton samples as the protocol continues to be refined. We used this technique to count both near-shore and open-ocean bacterial and archaeal picoplankton, from surface to bottom waters off southern California. This study compares diversity of prokaryotes based on the percentages of cells labeled with probes compared to DAPI-stained cells. Water samples were collected along a complete vertical profile, labeled with a range of probes, treated with chloramphenicol, and then counted with a CCD camera and light intensifier. We observed a significant decrease in both Bacteria and Archaea counts and a visible increase in the marine alpha-Proteobacteria subgroup in the open-ocean profile compared with the near-shore profiles. The overall Bacteria and Archaea percentages showed a decrease with distance from shore, an indication of a drop in nutrient levels (not measured). Both Bacteria and Archaea showed a decrease in percentage with depth, although the near-shore profiles reported a slight return in bottom waters, a probable result of benthic activity. Within the near-shore profiles, we observed a significantly higher percentage of Archaea (25%) at 150 meters.
 
Day: Thursday, Feb. 4
Time: Poster
Location: Sweeney Center
 
Code: CS55TH0577S