Posted by Chris on October 29, 2003 at 18:18:17:
A 6 October article in the San Francisco Chronicle notes that recent NASA satellite studies by oceanographers have confirmed an alarming deterioration of phytoplankton production in the world's oceans, possibly linked to worldwide warming of the oceans due to global warming. From satellite observations and shipboard surveys, the scientists have found that productivity of phytoplankton declined by more than 6 percent in the world's major ocean basins during the past 20 years, with primary production of the microscopic plants decreasing by more than 9 percent in the North Pacific. Not only does this decline have serious implications for marine food chains, of which phytoplankton are the basis, but it also means a dangerous decline in ocean plant life that aids in the absorption in the worst of the greenhouse gases, particularly carbon dioxide. Watson Gregg, a NASA biologist at the Goddard Space Flight Center in Greenbelt, MD, said more phytoplankton has been lost over the last two decades in areas with the most significant changes in ocean temperatures. Average summer ocean surface temperatures rose about 1.3 degrees Fahrenheit in the North Atlantic between the early 1980s and the late 1990s, and temperatures rose about 0.7 degrees in the North Pacific. "This research shows that ocean primary productivity is declining, and it may be the result of climate changes such as increased temperatures and decreased iron deposition into parts of the oceans," Gregg said. "This has major implications for the global carbon cycle." For the full story, see the 6 October San Francisco Chronicle article at: http://www.sfgate.com/cgi-bin/article.cgi?file=/chronicle/archive/2003/10/06/MN31432.DTL.
One potential cause of the worldwide die-off may be increasing acidity of ocean water as global temperatures increase. Increasing acidity results from carbon dioxide saturation, which increases with average surface water temperature, according to computer models. These models, recently developed by scientists at Lawrence Livermore Laboratory, show that over the next 100 years, at the current rate of ocean water temperature increases, increasing ocean acidity could cause irreversible losses of major marine ecosystems, according to a study noted in the 25 September San Franciscio Chronicle. For more see: http://www.sfgate.com/cgi-bin/article.cgi?file=/chronicle/archive/2003/09/25/MN120510.DTL.