Microplankton, Nanoplankton and Picoplankton Measurements from the U.S. JGOFS Arabian Sea Process Study

A component of U.S. Joint Global Ocean Flux Study (JGOFS) is the
Arabian Sea Process Study. Eleven cruises took place aboard the R/V
Thomas G. Thompson for about sixteen months from October 1994 until
January 1996. These cruises provided seasonal coverage of the annual
monsoon and inter-monsoon cycles in the area southeast of Oman - from
where the cruises were staged. The monsoons of the Arabian Sea drive
a uniquely intense carbon cycling system, and it is the goal of JGOFS
to better understand the role of the oceans in global carbon cycling.

Measurements of microplankton, nanoplankton and picoplankton were made
on six of the eleven cruises. The measurements include abundance,
biomass, biovolume, and zooplankton grazing (herbivory). The
measurements were made on preserved water samples, collected for
various depths using the rosette bottle sampler.

Microplankton (PI: David Caron)
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Microplankton measurements include vertical profiles of abundance,
biomass and grazing. These values are available for cruises TTN-043
and TTN-045. Microplankton were grouped by major taxa: diatoms,
dinoflagellates, other phytoplanktonic algae, non-loricate ciliates,
tintinnid ciliates, sarcodines, nauplii.

Profiles of microplankton abundance are available in cells per liter
for each taxon. Microplankton biovolumes were determined from
measurements of their linear dimensions (using volume equations for
appropriate geometric shapes). Biovolume estimates were converted to
carbon biomass (micrograms carbon per liter) for each taxon.

For microplankton grazing, shallow (5-10 m) and deep (35-80 m) water
samples were used. The dataset provides profiles of microzooplankton
grazing on phytoplankton per day and profiles of net phytoplankton
growth rate per day.

Nanoplankton (PI: David Caron)
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Profiles of nanoplankton abundance (cells per milliliter) and
biovolume (cubic micrometers per liter) are available for phototrophic
nanoplankton and heterotrophic nanoplankton on cruises TTN-043 and
TTN-045.

Picoplankton (PIs: Lisa Campbell and Michael Landry; Robert Olson)
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Profiles of picoplankton abundances were measured on cruises TTN-043,
TTN-045, TTN-050, and TTN-054 by Lisa Campbell and Michael Landry, and
on cruises TTN-049 and TTN-053 by Robert Olson. Abundance was
measured by flow cytometry. The following types of picoplankton were
enumerated: synechococcus, prochlorococcus, eukaryotic phytoplankton,
and heterotrophic bacteria (cells per milliliter).

The data is public domain and can be retrieved on-line at
"http://usjgofs.whoi.edu/jg/dir/jgofs/"

[This information was obtained from U.S. JGOFS website at WHOI.]