Table of Contents

• Dataset Description
  • Methods & Sampling
  • Data Processing Description
• Parameters
• Instruments
• Deployments
• Project Information
• Program Information
• Funding

Microplankton abundance and biomass from CTD casts

See Platform deployments for cruise specific documentation

David Caron
WHOI

Methods for microplankton counts


Samples for the enumeration of microplankton were preserved with a 10%
final concentration of acid Lugols in 1L amber glass bottles and stored
in the dark (Stoecker et al., 1994a). Samples were presettled and
concentrated 10-fold before final settling in counting chambers for the
enumeration of 20-200 micrometer organisms using inverted microscopy.
Microplankton were grouped by major taxa (diatoms, dinoflagellates,
other algae, non-loricate ciliates, tintinnid ciliates, sarcodines,
nauplii).  The high concentration of Lugols solution used for
preservation (to minimize losses of ciliate protozoa) precluded
distinguishing phototrophs from heterotrophs by autofluorescence.

Microplankton biovolumes were determined from measurements of their
linear dimensions (using volume equations for appropriate geometric
shapes).  Volume determinations of all assemblages at 4 depths from
each station were extrapolated to the 0-160 m water column.  Biovolume
estimates were converted to carbon biomass for each of the plankton
categories using published conversion factors.


References

    Stoecker, D. K., D. J. Gifford and M. Putt  (1994a)  Preservation
    of marine planktonic ciliates: losses and cell shrinkage during
    fixation.  Marine Ecology Progress Series, 110, 293-299.

The U.S. Arabian Sea Expedition which began in September 1994 and ended in January 1996, had three major components: a U.S. JGOFS Process Study, supported by the National Science Foundation (NSF); Forced Upper Ocean Dynamics, an Office of Naval Research (ONR) initiative; and shipboard and aircraft measurements supported by the National Aeronautics and Space Administration (NASA). The Expedition consisted of 17 cruises aboard the R/V Thomas Thompson, year-long moored deployments of five instrumented surface buoys and five sediment-trap arrays, aircraft overflights and satellite observations. Of the seventeen ship cruises, six were allocated to repeat process survey cruises, four to SeaSoar mapping cruises, six to mooring and benthic work, and a single calibration cruise which was essentially conducted in transit to the Arabian Sea.

The United States Joint Global Ocean Flux Study was a national component of international JGOFS and an integral part of global climate change research.

The U.S. launched the Joint Global Ocean Flux Study (JGOFS) in the late 1980s to study the ocean carbon cycle. An ambitious goal was set to understand the controls on the concentrations and fluxes of carbon and associated nutrients in the ocean. A new field of ocean biogeochemistry emerged with an emphasis on quality measurements of carbon system parameters and interdisciplinary field studies of the biological, chemical and physical process which control the ocean carbon cycle. As we studied ocean biogeochemistry, we learned that our simple views of carbon uptake and transport were severely limited, and a new "wave" of ocean science was born. U.S. JGOFS has been supported primarily by the U.S. National Science Foundation in collaboration with the National Oceanic and Atmospheric Administration, the National Aeronautics and Space Administration, the Department of Energy and the Office of Naval Research. U.S. JGOFS, ended in 2005 with the conclusion of the Synthesis and Modeling Project (SMP).