Toxic diatoms and domoic acid in natural and iron enriched waters of the oceanic Pacific

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Silver, M. W., Bargu, S., Coale, S. L., Benitez-Nelson, C. R., Garcia, A. C., Roberts, K. J., … Coale, K. H. (2010). Toxic diatoms and domoic acid in natural and iron enriched waters of the oceanic Pacific. Proceedings of the National Academy of Sciences of the United States of America, 107(48), 20762-20767. doi:10.1073/pnas.1006968107
Metadata
TitleToxic diatoms and domoic acid in natural and iron enriched waters of the oceanic Pacific
AuthorsW. Silver, S. Bargu, L. Coale, R. Benitez-Nelson, C. Garcia, J. Roberts, E. Sekula-Wood, W. Bruland, K. Coale
AbstractNear-surface waters ranging from the Pacific subarctic (58°N) to the Southern Ocean (66°S) contain the neurotoxin domoic acid (DA), associated with the diatom Pseudo-nitzschia. Of the 35 stations sampled, including ones from historic iron fertilization experiments (SOFeX, IronEx II), we found Pseudo-nitzschia at 34 stations and DA measurable at 14 of the 26 stations analyzed for DA. Toxin ranged from 0.3 fg·cell -1 to 2 pg·cell -1, comparable with levels found in similar-sized cells from coastal waters. In the western subarctic, descent of intact Pseudo-nitzschia likely delivered significant amounts of toxin (up to 4 μg of DA·m -2·d -1) to underlying mesopelagic waters (150-500 m). By reexamining phytoplankton samples from SOFeX and IronEx II, we found substantial amounts of DA associated with Pseudo-nitzschia. Indeed, at SOFeX in the Antarctic Pacific, DA reached 220 ng·L -1, levels at which animal mortalities have occurred on continental shelves. Iron ocean fertilization also occurs naturally and may have promoted blooms of these ubiquitous algae over previous glacial cycles during deposition of ironrich aerosols. Thus, the neurotoxin DA occurs both in coastal and oceanic waters, and its concentration, associated with changes in Pseudo-nitzschia abundance, likely varies naturally with climate cycles, as well as with artificial iron fertilization. Given that iron fertilization in iron-depleted regions of the sea has been proposed to enhance phytoplankton growth and, thereby, both reduce atmospheric CO 2 and moderate ocean acidification in surface waters, consideration of the potentially serious ecosystem impacts associated with DA is prudent.
JournalProceedings of the National Academy of Sciences of the United States of America
Date2010
Volume107
Issue48
Start page20762
End page20767
ISSN00278424
Subjects2 (1'h indole 3' carbonyl) thiazole 4 caboxylic acid methyl ester, 2,3,7,8 tetrachlorodibenzo para dioxin, green fluorescent protein, hypoxia inducible factor 1beta, interleukin 17, transcription factor FOXP3, unclassified drug, allergic encephalomyelitis, animal cell, animal experiment, animal model, cell compartmentalization, conference paper, controlled study, dendritic cell, immunological tolerance, lymphocyte differentiation, mouse, nonhuman, outcome assessment, priority journal, receptor affinity, regulatory T lymphocyte, signal transduction, T lymphocyte, Th17 cell, Diatoms, Geography, Iron, Kainic Acid, Neurotoxins, Pacific Ocean, Seawater, Time Factors, algae, Animalia, Bacillariophyta, Pseudo-nitzschia
NoteCited By (since 1996):9, CODEN: PNASA

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