open access

https://hdl.handle.net/2115/13457

Effect of aging time on the availability of freshly precipitated ferric hydroxide to coastal marine diatoms

英語

Thalassiosira weissflogii

2006-05

SPRINGER

MARINE BIOLOGY

149(2)

379-392

Cell growth and iron uptake of the coastal marine diatoms Chaetoceros sociale and Thalassiosira weissflogii were studied in the presence of short-aged amorphous ferric hydroxide (am-Fe(III)) media. These were prepared by aging for 1 day, 3 days, and 3 weeks after adding a small amount of ferric iron acidic stock solution to autoclaved filtered seawater and were experimentally measured in culture experiments at 10 degrees C for C. sociale and 20 degrees C for T. weissflogii. The order of cell yields for both species was: 1-day aged am-Fe(III) > 3-day aged am-Fe(III) >> 3-week aged am-Fe(III) media. The iron uptake rates by C. sociale during 0-1 day in 1 day and 3-day aged am-Fe(III) media were about two-thirds and one-fourths, respectively, lower than that in the direct Fe(III) input medium containing C. sociale into which an acidic Fe(III) stock solution was added directly. The longer aging time of am-Fe(III) in media results in reducing the supply of bioavailable iron in the media by the slower dissolution rate of am-Fe(III) with the longer aging time. These results suggest that the chemical and structural changes of freshly precipitated amorphous ferric hydroxide with short aging time affect their ability, such as iron solubility and dissolution rate to supply bioavailable iron for the phytoplankton growth. The chemical and structural conversion of solid iron phases with time is one of the most important processes in changing the supply of available iron to marine phytoplankton in estuarine and coastal waters and in iron fertilization experiments.

学術雑誌論文

Accepted Manuscript

The original publication is available at www.springerlink.com

0025-3162