METHODS

       

       Phytoplankton were collected, preserved, concentrated, and, if possible, counted on ship
board in order to retain fragile species, using a preservation and epifluorescence enumeration p
rocedure adapted from Murphy and Haugen (1985) and Shapiro et al. (1989).  Samples were collecte
d with water bottles or buckets (surface), preserved immediately with 0.5 % glutaraldehyde (fina
l concentration), and placed in a refrigerator for at least 1 hr and no more than 24.  An aliquo
t of this samples was filtered first through a 3 5m polycarbonate filter and collected on a 0.2 
5m polycarbonate filter.  This latter filter was mounted with immersion oil on a slide, refriger
ated, and always counted within 24 hr.  Another aliquot was stained with 0.03 % proflavine hemis
ulfate (final concentration) and filtered sequentially through 8 and 3 5m polycarbonate filters.
  Both filters were mounted on slides with immersion oil.  The 3 5m slides were refrigerated and
 counted within 48 hr; the 8 5m slides were frozen immediately and counted later back in the lab
.

       

       Phytoplankton were counted on an Olympus epifluorescence microscope with green and blue 
excitation.  Phytoplankton were counted to the most specific taxon possible.  In the 0.2 and 3 5
m fractions, these refer only to very broad categories.  In the 8 5m fraction more specific iden
tification was possible.  In cases where an identification could not be made, but an organism wa
s distinct and numerous, a name was assigned, which described its appearance.  Photographs and d
escriptions are on file at LUMCON and we are continuing to try to identify these organisms.



EXPLANATION OF PHYTOPLANKTON SPECIES DATA



Name = most specific taxonomic classification possible.  



Size = One of three size fractions on which counts were made

       0.2 -3 5m

       3 - 8 5m

       > 8 5m



Length = in the > 8 5m fraction, counts are usually made at least at two magnifications.  To av
oid counting the same organism twice, a length, usually 205m, is designated to separate what wil
l be counted at each magnification.  If the organism is greater than that length in one dimensio
n, it is counted at the lower magnification.  In a few cases counts were not made at two magnifi
cations or the counts were not clearly separated by a specific size.  In those cases the Length 
category is left blank and the count given is for all organisms > 8 5m.



a_h = distinguishes if the organisms is autotrophic or heterotrophic

       A = autotrophic

       H = heterotrophic

       Q = unknown



type = designates the general group of organisms to which the particular organism belongs

       D = diatom              CH = chlorophyte

       F = dinoflagellate      P = phytoflagellate

       CR = cryptomonad        B = heterotrophic bacteria (such as Beggiatoa)

       CI = ciliate            O = other

       C = cyanobacteria       Q = unknown     



References



Murphy, L.S., and E.M. Haugen.  1985.  The distribution and abundance of photorophic ultraplank
ton in the North Atlantic.  Limnol. Oceanogr. 30: 47-58.



Shapiro, L.P.,  E.M. Haugen, and E.J. Carpenter.  1989.  Occurrence and abundance of green-fluo
rescing dinoflagellates in surface waters of the Northwest Atlantic and Northeast Pacific Oceans
.  J. Phycol. 25: 189-191. 


