Northwest Fisheries Science Center

Display All Information

Document Type: Journal Article
Center: NWFSC
Document ID: 800
Title: Iron enrichment stimulates toxic diatom production in High Nitrate Low Chlorophyll areas
Author: C. G. Trick, Brian D. Bill, W. P. Cochlan, M. L. Wells, Vera L. Trainer, L. Pickell
Publication Year: 2010
Journal: Proceedings of the National Academy of Science

Oceanic High-Nitrate, Low-Chlorophyll (HNLC) environments have been highlighted for potential large-scale iron fertilizations to help mitigate global climate change.  Substantial controversy surrounds these initiatives, both in the degree of phytoplankton-sequestered carbon removal and magnitude of ecosystem impacts. One unifying observation from the previous open ocean experiments is that iron additions strongly stimulate production of pennate diatoms of the genus Pseudo-nitzschia in all HNLC regions. Most Pseudo-nitzschia species in coastal waters produce the neurotoxin domoic acid (DA), with their blooms often causing major detrimental mammal health and marine ecosystem impacts, but oceanic Pseudo-nitzschia species are believed to be non-toxic4,5.  Here we demonstrate that at least two Pseudo-nitzschia species in the northeast subarctic Pacific HNLC region do indeed produce DA.  The sparse pennate diatom community at Ocean Station PAPA (OSP, 50° N, 145°W) produced up to 48 pg DA L-1, and fresh isolates of P. turgidula[B1]  produced DA in laboratory cultures and in deck-board incubation experiments.  Nanomolar iron amendments increased both P. turgidul


Domoic acid production in HNLC regions of the northeast Pacific Ocean