Karner, M. B. University of Hawai'i, mkarner@soest.hawaii.edu
Taylor, T. B. Monterey Bay Aquarium Research Institute, taylor@mbari.org
DeLong, E. F. Monterey Bay Aquarium Research Institute, delong@wave.mbari.org
Karl, D. M. University of Hawai'i, dkarl@soest.hawaii.edu

 
BACTERIAL AND ARCHAEAL DISTRIBUTIONS AT THE HAWAI'I OCEAN TIME-SERIES STATION, ALOHA, IN THE NORTH PACIFIC OCEAN
 
Abundance of major microbial groups was assessed in the North Pacific subtropical gyre using fluorescently labeled polynucleotide probes (>100 bp) for ribosomal RNA in situ hybridization. Monthly cruises to the US-JGOFS station, ALOHA, part of the Hawai'i Ocean Time-series program, revealed relative abundances of Marine Group I Archaea, Marine Group II Archaea, and Bacteria, as compared to total cell counts using DAPI staining. Group I Archaea relative abundance was found to increase in the 250-1000 m depth range while low or nil at shallow depths. Group II Archaea generally peaked in the surface layer but their relative abundance stayed below 10 %. Group I Archaea relative abundance was up to one third of total cells at 1000 m, sometimes equaling Bacterial numbers at this depth. Bacteria were dominant at shallow depths, with abundance between 80 and 90 % of the DAPI count. Archaeal and Bacterial numbers when summed were sufficient to account for the independent DAPI count. Relative Archaeal abundances showed marked differences between the monthly cruises. At greater depths, cell to cell comparison revealed that DAPI does not always stain probe positive cells, indicating a possible underestimation of microbial numbers by up to 25 %.
 
Day: Tuesday, Feb. 2
Time: Poster
Location: Sweeney Center
 
Code: SS41TU0515S