Primary production of prochlorophytes, cyanobacteria, and eucaryotic ultraphytoplankton: Measurements from flow cytometric sorting

Abstract

A partitioning of ultraphytoplankton primary production among prochlorophytes, cyanobacteria, and eucaryotic algae was made by shipboard flow cytometric sorting of 10C‐labeled cells. Aggregate primary production was derived from the sum, over all three ultraplankton groups, of the product of cell abundance and cell‐specific rate of 14C uptake which ranged from 0.03 to 4 fg C cell−1 h−1 for prochlorophytes and 0.2 to 10 fg C cell−1 h−1 for cyanobacteria. Results indicated that the dominant primary producer was not necessarily the numerical dominant nor necessarily the group with the highest cell‐specific rate of 14C uptake. Generally, eucaryotic ultraphytoplankton are dominant because of their high cell‐specific rate of 14C uptake and in spite of their relatively low abundance. Less often, it seems, procaryotic picoplankton may dominate in spite of their low cell‐specific rate of 14C uptake because of their high abundance.

Ecology and Diversity of Picoeukaryotes

“…When exploring the ecological contributions of picoplankton, biomass is an important parameter to quantify. Generally, although picoeukaryotes are less abundant than the picocyanobacteria, they are larger in terms of cell size and cell biomass (Li 1994;Shalapyonok et al 2001;Worden et al 2004). Using the above approaches natural picophytoeukaryote populations in the coastal Pacific contained 530 + 180 fgC/cell on average, while Synechococcus contained 82 fgC/cell and Prochlorococcus 39 fgC/cell .…”

“…In the North Atlantic, FCM was used to demonstrate that picoeukaryotes formed a large portion of the primary producer biomass in this size fraction. However, when only looking at abundance they appeared much less important than the picocyanobacteria (Li 1994;Li et al 1992). Later, eukaryotes mostly in the 2 -4 mm size range, but including picoeukaryotes, were shown to comprise a significant portion of the phytoplankton biomass in the Sargasso Sea using size-calibrated FCM (Durand 2001).…”

Genomic island genes in a coastal marine Synechococcus strain confer enhanced tolerance to copper and oxidative stress

“…Marine picocyanobacteria including Synechococcus and its sister taxon Prochlorococcus, are a highly diverse group that are found throughout the world oceans, and contribute significantly to global primary production (Li, 1994;Richardson and Jackson 2007). Multiple Synechococcus clades or 'species' have been identified using various phylogenetic marker genes, and many of these clades are found to coexist in a single location (Ferris and Palenik 1998;Rocap et al, 2002;Zwirglmaier et al, 2007).…”

Morphology and DNA content of bacterioplankton in the northern Gulf of Mexico: analysis by epifluorescence microscopy and flow cytometry

“…Phototrophic prokaryotes often dominate phytoplankton in oligotrophic waters (Campbell et al 1994, Jochem 1995 and contribute a large percentage of primary production , Li 1994. Heterotrophic bacteria constitute an important share of total plankton biomass similar to or higher than that of primary producers, and play a significant role in pelagic heterotrophic processes (Cho & Azam 1990).…”