Savior or Killer? Algae May Save the Planet or Cause Mass Extinctions

Photo courtesy of Lee Nachtigal's photostream

A slimy, often microscopic organism, algae* is quickly becoming the frequent subject of environmental news. Two stories this week have very different things to say about algae: One says it could help curb climate change by gorging on carbon dioxide. The other says it may have been the killer in the world's great mass extinctions of species.

A story by Alliance Francaise Presse (AFP) says that algae are gaining notoriety as a potential fuel source--one that could curtail the world's petroleum addiction. And while much ado has been made over the potential for soy, corn and sugarcane to be the next big alternative fuel crops, algae have a few advantages over the competitors. One is that they are incredibly high in fat, far higher than soybeans. They also grow extremely quickly, and can grow in swamps, stagnant pools, or even wastewater. Another advantage is that, unlike food crops, algae do not compete with the world's food supply. Algae also have the ability to soak up vast amounts of carbon dioxide. University labs and even corporations are starting to put big money into research, including ExxonMobil.

Another story, by Terra Daily, says that algae may have been the perpetrator behind the world's great species extinctions. Two scientists have found a correlation between large die-offs of species and spikes in fossil algae across the planet. Sudden warming in the water or an injection of dust or sediment from land can evoke a harmful algal bloom that kills masses of fish, shellfish or even humans. As the theory goes, nutrient-rich fallout from disasters such as super volcanoes and cosmic impacts could have landed in water, becoming food for algae. If the algae grew out of control because of it, the toxic varieties could release powerful neurotoxins, which land plants could soak up through their roots and poison herbivorous animals. As the world's temperature reaches historic highs, toxic algae in the United States appears to be spreading -- moving northward in ponds, lakes and in ocean waters along the coasts.

*There are many species of algae, ranging in size (and color), from microscopic, one-celled organisms to larger, more complex versions, like seaweed.