| Budget Amount *help |
¥5,100,000 (Direct Cost: ¥5,100,000)
Fiscal Year 1989: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1988: ¥4,300,000 (Direct Cost: ¥4,300,000)
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| Research Abstract |
In natural seawater, dissolved Fe(OH)^+_ is in equilibrium with particulate iron, and its concentration was found to be 0.048 mug/l. The solubility rate,of particulate iron depends on the particulate iron concentration, and the rates of 0.0035, 0.010 and 0.017 mug/l/day were observed when the initial particulate iron concentrations were 1, 3 and 5 mug/l, respectively.
Photoreduction of Fe(lll) by several dissolved hydroxylcarboxylic acids, especially glucaric and gluconic acids, was observed under laboratory conditions. About 130 muM of gluconic acid was detected by HPLC in a diatom culture ( 10^5 cells/ml ) after 20 min exposure to ultraviolet radiation.
Since Fe^<2+> is necessary for the growth of phytoplankton and marine algae, the diffusion of Fe^<2+> from propagation cages made of iron, which were moored on the coastal floors, was monitored. About 1-2 mug/l of Fe^<2+> were detected within 40 m around the cages. We think the cages are suitable for phytoplankton and marine algae propagation.
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