Phytoplankton blooms in Ocean

http://www.sciencedaily.com/releases/2010/07/100716140917.htm

Old Theory of Phytoplankton Growth Overturned, Raise Concerns for Ocean Productivity

ScienceDaily (July 16, 2010) — A new study concludes that an old, fundamental and widely accepted theory of how and why phytoplankton bloom in the oceans is incorrect.

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"What the satellite data appear to be telling us is that the physical mixing of water has as much or more to do with the success of the bloom as does the rate of phytoplankton photosynthesis," Behrenfeld said. "Big blooms appear to require deeper wintertime mixing."

That's a concern, he said, because with further global warming, many ocean regions are expected to become warmer and more stratified. In places where this process is operating -- which includes the North Atlantic, western North Pacific, and Southern Ocean around Antarctica -- that could lead to lower phytoplankton growth and less overall ocean productivity, less life in the oceans. These forces also affect carbon balances in the oceans, and an accurate understanding of them is needed for use in global climate models.

Worth noting, Behrenfeld said, is that some of these regions with large seasonal phytoplankton blooms are among the world's most dynamic fisheries.

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Phytoplankton bloom off Argentina Coast

Please see a photo of a large Phytoplankton bloom off Argentina Coast.

http://earthobservatory.nasa.gov/NaturalHazards/view.php?id=42618&src=nha

Jewel-toned waters glimmered off the coast of Argentina in early February 2010 as a phytoplankton bloom colored the Atlantic Ocean’s waters blue-green. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured this true-color image on February 9, 2010. Roughly mimicking the shape of the shoreline to the west, the phytoplankton bloom forms a semicircle.

Tiny, plant-like marine organisms, phytoplankton often thrive in nutrient-rich waters, and this bloom might owe its existence to multiple factors. The sea floor drops dramatically off the east coast of South America, and water welling up from lower depths can bring nutrients that feed phytoplankton. In addition, dust storms, such as the one that occurred in late January 2010, can also deposit iron and other nutrients into the ocean.