Fig. 4.

(A) Cellular iron quotas ($\mathrm{\mu }$mol Fe:mol C) in Chaetoceros and Pseudo-nitzschia from incubations. Bars are geometric means $\pm$ SE. (B) Time course for site C-Low1 of chlorophyll a ($>$5 $\mathrm{\mu }$m size fraction only), biogenic silica, diatom relative transcript proportions, and relative transcript proportions of Pseudo-nitzschia and Chaetoceros within diatoms. The treatments shown are control (green), iron addition (Fe, red), and iron removal (DFB, blue). Plots are grouped by initial iron state (high or low).