Dataset: microplankton
Deployment: TT045

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.

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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.
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