Climate change is not only causing algae to bloom out of control, it's increasing its toxicity as well.
The toxic algal blooms are threatening wildlife and could potentially contaminate human drinking water, an Oregon State University news release reported.
As the process of nutrient enrichment called "eutrophication," caused by man-made pollutants increases so will the amount of harmful cyanobacteria in algal blooms.
"Cyanobacteria are basically the cockroaches of the aquatic world," said Timothy Otten, a postdoctoral scholar in the OSU College of Science and College of Agricultural Sciences, whose work has been supported by the National Science Foundation. "They're the uninvited guest that just won't leave."
Cyanobacteria were present on Earth as far back as 3.5 billion years, when there was no oxygen and very little life on the young planet. The bacteria may have even created the oxygen that allowed new life forms to evolve.
These bacteria are doing what they have always done; adapting to harsh conditions even if it puts other species in danger.
A Cyanobacteria called Microcystis sp. "thrives in warm, nutrient-rich and stagnant waters around the world," and is of particular concern. It often appears as a "green scum" on the surface of the water. They are highly toxic, and can choke out non-poisonous strains.
"When one considers their evolutionary history and the fact that they've persisted even through ice ages and asteroid strikes, it's not surprising they're extremely difficult to remove once they've taken hold in a lake," Otten said. "For the most part, the best we can do is to try to minimize the conditions that favor their proliferation."
"[If] you go looking for toxin-producing cyanobacteria, chances are you won't have to look very long until you find some," he said.
At least one-third of the Earth's lakes over 10 acres large are believed to be infested with dangerous bacteria. Some lakes, such as Lake Erie, grow such large algal blooms that they can be seen from space.
"Water quality managers have a toolbox of options to mitigate cyanobacteria toxicity issues, assuming they are aware of the problem and compelled to act," Otten said. "But there are no formal regulations in place on how to respond to bloom events."
"We need to increase public awareness of these issues," he said. "With a warming climate, rising carbon dioxide levels, dams on many rivers and overloading of nutrients into our waterways, the magnitude and duration of toxic cyanobacterial blooms is only going to get worse."
