In early August, nearly half a million people in Toledo, Ohio were told not to use their tap water for drinking, cooking or bathing. The cause was a bloom of algae in Lake Erie, in this case a microbe known as cyanobacteria, which produces a dangerous toxin called microcystin.
The water ban in Toledo was lifted after only two days, but toxic algae blooms like these are becoming increasingly common in coastal oceans and freshwater bodies around the world. The algae and bacteria responsible for such blooms need warm temperatures and the nutrients phosphorus and nitrogen to grow. Unfortunately, both of these things are on the upswing.
Climate change is warming the waters in many places around the world, including the Great Lakes. Fertilizers and other man-made pollutants associated with modern agriculture and fossil fuel production are flowing into rivers and lakes, providing the nutrients for these waterborne bacteria. Between these two things, cyanobacterial blooms are increasing around the world.
Cyanobacteria are ancient organisms, dating back a few billion years. It isn’t actually clear why it is that they produce toxic microcystin, but this substance can cause paralysis, seizures, liver damage, and, in high doses, death.
The conditions these bacteria face today – warming waters and huge amounts of nitrogen and phosphorus being dumped into rivers and lakes – are historically unprecedented. As a result, events like the recent scare in Toledo, are likely to become more common all the time. In fact, toxic algae blooms may be the new normal.
**********
.
Web Links
Driven by Climate Change, Algae Blooms Behind Ohio Water Scare Are New Normal
Cyanobacteria Are Far From Just Toledo’s Problem
Photo, posted January 1, 2014, courtesy of Harald Groven via Flickr.
.
Earth Wise is a production of WAMC Northeast Public Radio.