Nerve Toxins In The Deep

Some of the species in the genus Pseudo-nitzschia are nasty little diatoms.  They produce domoic acid, a neurotoxin typically to blame for all sorts of marine vertebrate deaths.  Alfred Hitcocks’s 1963 film “The Birds” dramatizes a bird attack incident blamed on domoic acid. Human consumption of shellfish that has filtered Pseudo-nitzschia leads to amnesic shellfish poisoning.  A great meal of Oysters Rockefeller can lead to short-term memory loss.  It appears, and we as humans are to blame, that algal blooms dominated by these wee-beasties is increasing in both frequency and duration.

A new study in Nature Geoscience finds that domoic acid can make it to the deep.  Sediment traps set at 500m and 800m below the ocean surface off southern California. “The sinking particles contain over five times the United States federal limit of domoic acid.” The peaks coincided lagged only by a few days behind peaks in surface concentration implying that transport of domoic acids was immediate.  Previous work found that for both organisms in the continental shelf and throughout the water column domoic acid is pervasive.  This study suggests that domic acid concentrations in deep-sea organisms could also be considerable.

Add this to another way anthropogenic disturbance is reaching into the deep.

[googlemap lat="34.1890858311724" lng="-120.003662109375" width="300px" height="300px" zoom="7" type="G_SATELLITE_MAP"]Santa Barbara Basin[/googlemap]

Sekula-Wood, E., Schnetzer, A., Benitez-Nelson, C., Anderson, C., Berelson, W., Brzezinski, M., Burns, J., Caron, D., Cetinic, I., Ferry, J., Fitzpatrick, E., Jones, B., Miller, P., Morton, S., Schaffner, R., Siegel, D., & Thunell, R. (2009). Rapid downward transport of the neurotoxin domoic acid in coastal waters Nature Geoscience DOI: 10.1038/ngeo472

Dr. M (1606 Posts)

Craig McClain is the Assistant Director of Science for the National Evolutionary Synthesis Center, created to facilitate research to address fundamental questions in evolutionary science. He has conducted deep-sea research for 11 years and published over 40 papers in the area. He has participated in dozens of expeditions taking him to the Antarctic and the most remote regions of the Pacific and Atlantic. Craig’s research focuses mainly on marine systems and particularly the biology of body size, biodiversity, and energy flow. He focuses often on deep-sea systems as a natural test of the consequences of energy limitation on biological systems. He is the author and chief editor of Deep-Sea News, a popular deep-sea themed blog, rated the number one ocean blog on the web and winner of numerous awards. Craig’s popular writing has been featured in Cosmos, Science Illustrated, American Scientist, Wired, Mental Floss, and the Open Lab: The Best Science Writing on the Web.





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One comment on “Nerve Toxins In The Deep
  1. Wow, that’s frightening. Think of all the poor filter feeders! We should do a bioassay in our study critters for this stuff. I wonder if you need fresh or frozen material.

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