BATON ROUGE LSU's Sibel Bargu, along with her former graduate student Ana Garcia, from the Department of Oceanography and Coastal Sciences in LSU's School of the Coast & Environment, has discovered toxic algae in vast, remote regions of the open ocean for the first time. The recent findings were published in the Nov. 8 edition of one of the most prestigious scientific journals, the Proceedings of the National Academy of Sciences, or PNAS.
Harmful algal blooms, or HABs, are reported as increasing both geographically and in frequency along populated coastlines. Bargu's research shows that the ubiquitous diatom Pseudo-nitzschia an alga that produces the neurotoxin, domoic acid, or DA, in coastal regions actually also produces DA at many locations in the open Pacific. The presence of these potent toxins in deep water environments is worrisome, given that in coastal waters, where the phenomenon has been studied, DA can enter the food chain, forcing the closure of some fisheries and poisoning marine mammals and birds that feed on the contaminated fish. The main concern, though, is that the adding of iron to ocean waters one of the most commonly proposed strategies to reduce global warming appears now to likely result in promoting toxic blooms in the ocean.
Because both natural and artificial iron additions in open ocean waters can result in phytoplankton blooms in large areas of the sea that are deficient in the metal, and also because phytoplankton take up carbon dioxide and iron in addition to seawater, it has been suggested as a remedy to combat global warming. Basically, the new growth of photosynthetic cells draws carbon dioxide into the sea, reducing the amount of this gas in the atmosphere and thus reducing its warming effect. However, Pseudo-nitzschia-like cells have been known for a while to be common responders in a number of iron fertilization experiments conducted at sea over more than a decade.
To address th
|Contact: Ashley Berthelot|
Louisiana State University