Fig. 11.27 Dissolved [nitrate + >nitrite] vs. soluble reactive phosphate at Station
ALOHA (HOTS) and at the BATS station (31°45′N, 64°10′W) in the Sargasso Sea.
Probably the difference is attributable to greater relative importance of nitrogen
fixation in the subtropical North Atlantic.
(^) (After Wu et al. 2000.)
Nothing exactly comparable appears to have been done in the NPSG, but Van Mooy
and Devol (2008) used tracer levels of radioactive phosphate to examine the rates of
ribosomal RNA synthesis (PO 4 3− required) in Prochlorococcus, “eukaryotes”, and
heterotrophic bacteria at HOT in July of 2003 and 2004. Measurements were made for
incubations with added PO 4 3−, NH 4 + and NO 3 −. Somewhat like the Moore et al.