New ocean acidification study shows added danger to already struggling coral reefs

Ocean acidification could compromise the successful fertilization, larval settlement and survivorship of Elkhorn corals, new research reveals. (Credit: Evan D'Alessandro, University of Miami)

http://www.sciencedaily.com/releases/2010/11/101108151328.htm
ScienceDaily (Nov. 13, 2010) — Over the next century, recruitment of new corals could drop by 73 percent, as rising carbon dioxide levels turn the oceans more acidic, suggests a new study led by scientists at the University of Miami Rosenstiel School of Marine and Atmospheric Science. The research findings reveal a new danger to the already threatened Caribbean and Florida reef Elkhorn corals.

Oceanography researchers discover toxic algae in open water

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

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

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.
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.

Extreme global warming in the ancient past

The image shows the the scientific drilling ship JOIDES Resolution docked in Hobart, Tasmania. (Credit: John Beck, IODP)

ScienceDaily (Nov. 11, 2010) — Variations in atmosphere carbon dioxide around 40 million years ago were tightly coupled to changes in global temperature, according to new findings published in the journal Science. The study was led by scientists at Utrecht University, working with colleagues at the NIOZ Royal Netherlands Institute for Sea Research and the University of Southampton.

"We found a close correspondence between carbon dioxide levels and sea surface temperature over the whole period, suggesting that increased amounts of carbon dioxide in the atmosphere played a major role in global warming during the MECO," said Bohaty.

The researchers consider it likely that elevated atmospheric carbon dioxide levels during the MECO resulted in increased global temperatures, rather than vice versa, arguing that the increase in carbon dioxide played the lead role.

"The change in carbon dioxide 40 million years ago was too large to have been the result of temperature change and associated feedbacks," said co-lead author Peter Bijl of Utrecht University. "Such a large change in carbon dioxide certainly provides a plausible explanation for the changes in Earth's temperature."

full article at: http://www.sciencedaily.com/releases/2010/11/101110101313.htm