Robert Bidigare
University of Hawaii

Notes on Sampling Methodology


The distribution of pigments in different size fractions was
investigated at the six long stations occupied during each cruise.
Seawater samples were collected from fours depths:  one in the mixed
layer, and the other three above, within and below the deep chlorophyll
maximum layer.  Size-fractionated pigment samples were prepared by
serially passing seawater (1-4 L) through 25 mm Gelman in-line filter
holders equipped with filters of decreasing porosity.  These included
18 and 2 micron Poretics polycarbonate filters, followed by a Whatman
GF/F glass fiber filter (nominal porosity of 0.7 micron).  Filters were
wrapped in aluminum foil, immediately frozen in liquid nitrogen,
shipped to Hawaii following each cruise, and stored at -80oC until HPLC
analysis.