Table of Contents

• Coverage
• Dataset Description
  • Methods & Sampling
  • Data Processing Description
• Data Files
• Related Publications
• Parameters
• Instruments
• Deployments
• Project Information
• Program Information
• Funding

Bacteria Abundance, Biomass and Chlorophyll: Water Column Samplesa

BG 235 - Methods used for chlorophyll a (chla) analysis and bacteria biomass determination

Core Sampling techniques:

Sampling methods for recovery of chlorophyll a and bacteria from sea ice cores follows those described in 
Garrison and Buck (1986)

Recommendations for reporting were used as outlined by: Horner, R. et al.,(1992)

Analytic Techniques:

Chla (mg m^-3):

• determined fluorometrically (Turner Designs 10AU Fluorometer) following extraction in 90% acetone (Parsons et al., 1984)
• ice core chla corrected to account for chla in filtered sea water (FSW) added to core sections during melting

Bacteria cell abundance (cells m^-3) and biomass (mg C m^-3):

LMG 0106

• preserved (0.5% glutaraldehyde) samples stained with 4',6-diamidino-2-phenylindole (DAPI; 0.1 to 0.3% final concentration), filtered through 0.2 mm black, polycarbonate membrane filters, and mounted onto glass microscope slides on the ship (within 24 hours following collection)
• bacteria enumerated using epifluorescence microscopy and sized using digital images taken with Image Pro Plus
• bacteria biomass determined using cell abundance, cell biovolume (BV; mm³; as determined from mean length and width measurements), and an allometric conversion factor for bacterial carbon per volume specific for DAPI-stained bacteria (cellular carbon = 218 X BV^0.86; Loferer-Krossbacher et al., 1998).
• ice core samples corrected for FSW dilution

NBP 0104

• preserved (0.5% glutaraldehyde) samples stained with SYBR Gold (0.01% final concentration), filtered through 0.2 mm Anodisc filters (Whatman), and mounted onto glass microscope slides at home institution (~1-2 months following collection)
• bacteria enumerated using epifluorescence microscopy and sized using digital images taken with Image Pro Plus
• bacteria biomass determined using cell abundance, cell biovolume (BV; mm³), and an allometric conversion factor for bacterial carbon per volume specific for Acridine Orange-stained bacteria (cellular carbon = 89.9 X BV^0.59; Simon and Azam, 1989). Note: an AO-specific carbon per volume conversion factor was used in calculating biomass in SYBR Gold-stained samples because both AO and SYBR Gold stain bacteria cells similarly relative to DAPI (unpublished data).
• ice core samples corrected for FSW dilution

Data from LMG0106 (July-August, 2001) added in June 2002.

Updated: April 21, 2006

#  Bacteria data from Southern Ocean GLOBEC
#     C. Fritsen and F. Stewart
#            * BactAbun = bacterial abundance = cells m-3
#            * BactBio = bacterial biomass = mg C m-3 = ug C l-1
#            * chla = mg chla m-3 = ug chla l-1

Chla (mg m^-3):

• determined fluorometrically (Turner Designs 10AU Fluorometer) following extraction in 90% acetone (Parsons et al., 1984)
• ice core chla corrected to account for chla in filtered sea water (FSW) added to core sections during melting

Bacteria cell abundance (cells m^-3) and biomass (mg C m^-3):

LMG 0106

• preserved (0.5% glutaraldehyde) samples stained with 4',6-diamidino-2-phenylindole (DAPI; 0.1 to 0.3% final concentration), filtered through 0.2 mm black, polycarbonate membrane filters, and mounted onto glass microscope slides on the ship (within 24 hours following collection)
• bacteria enumerated using epifluorescence microscopy and sized using digital images taken with Image Pro Plus
• bacteria biomass determined using cell abundance, cell biovolume (BV; mm³; as determined from mean length and width measurements), and an allometric conversion factor for bacterial carbon per volume specific for DAPI-stained bacteria (cellular carbon = 218 X BV^0.86; Loferer-Krossbacher et al., 1998).
• ice core samples corrected for FSW dilution

The fundamental objectives of United States Global Ocean Ecosystems Dynamics (U.S. GLOBEC) Program are dependent upon the cooperation of scientists from several disciplines. Physicists, biologists, and chemists must make use of data collected during U.S. GLOBEC field programs to further our understanding of the interplay of physics, biology, and chemistry. Our objectives require quantitative analysis of interdisciplinary data sets and, therefore, data must be exchanged between researchers. To extract the full scientific value, data must be made available to the scientific community on a timely basis.

The U.S. Global Ocean Ecosystems Dynamics (U.S. GLOBEC) program has the goal of understanding and ultimately predicting how populations of marine animal species respond to natural and anthropogenic changes in climate. Research in the Southern Ocean (SO) indicates strong coupling between climatic processes and ecosystem dynamics via the annual formation and destruction of sea ice. The Southern Ocean GLOBEC Program (SO GLOBEC) will investigate the dynamic relationship between physical processes and ecosystem responses through identification of critical parameters that affect the distribution, abundance and population dynamics of target species. The overall goals of the SO GLOBEC program are to elucidate shelf circulation processes and their effect on sea ice formation and krill distribution, and to examine the factors which govern krill survivorship and availability to higher trophic levels, including penguins, seals and whales. The focus of the U.S. contribution to the international SO GLOBEC program will be on winter processes. This component will focus on the distribution and activities of sea ice microbial communities. This will be accomplished using an integrated combination of sampling (vertical profiles, horizontal surveys, and under-ice surveys) and observational protocols. Experiments will be designed to estimate microbial activity within the sea ice and at the ice-seawater interface. The research will be coordinated with components studying the water column productivity and the sea ice habitat. The result of the integrated SO GLOBEC program will be to improve the predictability of living marine resources, especially with respect to local and global climatic shifts.

U.S. GLOBEC (GLOBal ocean ECosystems dynamics) is a research program organized by oceanographers and fisheries scientists to address the question of how global climate change may affect the abundance and production of animals in the sea.

The U.S. GLOBEC Program currently had major research efforts underway in the Georges Bank / Northwest Atlantic Region, and the Northeast Pacific (with components in the California Current and in the Coastal Gulf of Alaska). U.S. GLOBEC was a major contributor to International GLOBEC efforts in the Southern Ocean and Western Antarctic Peninsula (WAP).

U.S. GLOBEC (GLOBal ocean ECosystems dynamics) is a research program organized by oceanographers and fisheries scientists to address the question of how global climate change may affect the abundance and production of animals in the sea.

The U.S. GLOBEC Program currently had major research efforts underway in the Georges Bank / Northwest Atlantic Region, and the Northeast Pacific (with components in the California Current and in the Coastal Gulf of Alaska). U.S. GLOBEC was a major contributor to International GLOBEC efforts in the Southern Ocean and Western Antarctic Peninsula (WAP).