'Alarming' Satellite Data Shows Reduction in Ocean Life, Increased Global Warming.
The ocean's food chain is based on the growth of billions upon billions of microscopic plants. New satellite data show that ocean warming is reducing these plants and imperiling ocean fisheries and marine life, as reported in an article in the Nov. 7 issue of the scientific journal Nature.
"We show on a global scale that the growth of these plants, called phytoplankton, is strongly tied to changes in the warming of the ocean," said David Siegel, co-author and professor of marine science in the Department of Geography at the University of California, Santa Barbara. Siegel is also director of the Institute for Computational Earth System Science (ICESS).
"Phytoplankton grow faster in a cool ocean and slower in a warm one," said Siegel. "The scary part is that the oceans are warming now -- probably caused by our emissions of greenhouse gases, like carbon dioxide."
The microscopic plants are predicted to grow even slower in the warmer oceans of the future, according to the researchers, which in turn will reduce the food available to fish and other organisms, including marine birds and mammals, that are supported by the ocean's food chain.
Phytoplankton are responsible for about the same amount of photosynthesis each year as all the plants on land combined.
Another disturbing result of reduced phytoplankton, say researchers, is that the atmosphere depends on the consumption of atmospheric carbon dioxide by these plants. Reduced phytoplankton means less carbon dioxide is taken up by the ocean, which could speed global warming, contributing to a vicious cycle of increased warming.
"Rising levels of carbon dioxide in the atmosphere play a big part in global warming," said lead author Michael Behrenfeld of Oregon State University. "This study shows that as the climate warms, phytoplankton growth rates go down and along with them the amount of carbon dioxide these ocean plants consume. That allows carbon dioxide to accumulate more rapidly in the atmosphere, which would produce more warming."
The findings are from a NASA-funded analysis of data from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) instrument on the OrbView-2 spacecraft, launched in 1997. The uninterrupted nine-year record shows in great detail the ups and downs of marine biological activity or productivity from month to month and year to year.
Scientists made their discovery by comparing the SeaWiFS record of the rise and fall of global ocean plant life to different measures of recent global climate change. The climate records included several factors that directly affect ocean conditions, such as changes in sea surface temperature and surface winds. The results support computer model predictions of what could happen to the world's oceans as the result of prolonged future climate warming.
"When we compared changes in phytoplankton activity with simultaneous changes in climate conditions, the agreement between the two records was simply astonishing," Behrenfeld said.
((Comments on this story may be sent to email@example.com))
((Distributed via M2 Communications Ltd - http://www.m2.com))
|Printer friendly Cite/link Email Feedback|
|Date:||Dec 7, 2006|
|Previous Article:||Impotence Drugs May Help Body Fight Cancer.|
|Next Article:||Progenitor Cell Therapy Selects Thermal Packaging from Minnesota Thermal for Shipping Needs.|