University of North Carolina: Global Warming
Harmful algae taking advantage of global war - 04/03/08
Hans Paerl, a University of North Carolina at Chapel Hill Institute of Marine Sciences Professor and co-author of the Science paper, calls the algae the "cockroach of lakes." It's everywhere and it's hard to exterminate - but when the sun comes up it doesn't scurry to a corner, it's still there, and it's growing, as thick as 3 feet in some areas.
The algae has been linked to digestive, neurological and skin diseases and fatal liver disease in humans. It costs municipal water systems many millions of dollars to treat in the United States alone. And though it's more prevalent in developing countries, it grows on key bodies of water across the world, including Lake Victoria in Africa, the Baltic Sea, Lake Erie and bays of the Great Lakes, Florida's Lake Okeechobee and in the main reservoir for Raleigh, N.C.
"This is a worldwide problem," said Paerl, Kenan Professor of marine and environmental sciences in UNC's College of Arts and Sciences.
"It's long been known that nutrient runoff contributes to cyanobacterial growth. Now scientists can factor in temperature and global warming," said Paerl, who, with professor Jef Huisman from the University of Amsterdam, the Netherlands, explains the new realization in Science paper.
Warmer weather has also created longer growing seasons, and it's enabled cyanobacteria to grow in northern waters previously too cold for their survival. Species first found in southern Europe in the 1930s now form blooms in northern Germany, and a Florida species now grows in the Southeastern U.S. Others have appeared recently places as far north as Montana and throughout Canada.
"It's ironic," Paerl said. "Without cyanobacteria, we wouldn't be here. Animal life needed the oxygen the algae produced." Now, however, it threatens the health and livelihood of people who depend on infested waters for drinking water or income from fishing and recreational use.
