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Arsenic in the Marine Environment: A close coupling with Phosphate. Misty Blakely Aquatic Chemistry December 3 rd , 2007. Marine Cycling of Arsenic. Abiotic Sources: River run-off Atmospheric deposition Water intrusions. Biotic Sources: Phytoplankton Bacteria.
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Arsenic in the Marine Environment: A close coupling with Phosphate Misty Blakely Aquatic Chemistry December 3rd, 2007
Marine Cycling of Arsenic • Abiotic Sources: • River run-off • Atmospheric deposition • Water intrusions • Biotic Sources: • Phytoplankton • Bacteria Fig. 3. Adapted from Sanders, 1980.
Speciation in the Marine Environment • Arsenate • Arsenite • Methylarsinic Acid • Dimethylarsenic Acid Fig. 2. Adapted from Andreae, 1979 Fig. 1. Adapted from online Google image.
Biotic interactions and speciation Fig. 5. Adapted from Cutter, et. al., 2001 Fig. 4. Adapted from Cutter, 1992
Arsenate and Phosphate Fig. 6. Adapted from Andreae, 1979
Apte, et. al., 1986 Spring Diatom Bloom Fig. 7. Adapted from Apte, et. al., 1986 No coupling between phosphate and arsenate? Discrimination factors! Fig. 8. Adapted from Apte, et. al., 1986
Conclusions • Arsenic has complex chemistry in the marine environment • Most of the marine cycling is due to biology • Can interfere with phosphate uptake in phytoplankton • Arsenic is toxic and increasing!