Pesca predatória causa o declínio acelerado de comunidades e espécies marinhas

Oceanography researchers discover toxic algae in open water / Oceanógrafos descobrem alga toxica em areas remotas dos oceanos

ScienceDaily (Nov. 13, 2010) — Louisiana State University'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.


Pela primeira vez, algas tóxicas foram observadas em areas remotas dos oceanos, muito distantes da costa. 

Microscopic image of Pseudo-nitzschia. (Credit: Image courtesy of Ross Del Rio)

http://www.sciencedaily.com/releases/2010/11/101111133220.htm

The findings were published in the Nov. 8 edition of the Proceedings of the National Academy of Sciences(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.