Controlling light could combat toxic algae blooms

MU water quality expert Rebecca North explains how reducing the amount of light that reaches lake water could fight toxic algae blooms.

December 4, 2020 


Brian Consiglio: Lakes around the world are becoming increasingly green as the result of harmful algae blooms. Algae is composed of cyanobacteria, which produces toxins that can infest human drinking water and poison marine ecosystems.

Now, a professor of water quality at the University of Missouri, Rebecca North, is working to combat toxic algae blooms by reducing the amount of light that reaches lake water. The less light that reaches the water, the less algae can grow.

North: “I got the idea, actually, when I was vacationing in the Rocky Mountains and seeing all the beautiful turquoise-colored glacial lakes. The reason they look that way is because they have all this glacial rock flour in them. And they tend to be really clear with good water quality, and not have these harmful algae blooms.”

Consiglio: North found that adding glacial rock flour to water results in darkening the water’s color, which leads to a substantial decline in harmful algae growth. Since the algae’s cyanobacteria thrive on warmth and light, the more intense sunlight brought about by climate change has created more frequent and more harmful algae blooms, making the need to combat algae growth more important than ever before.

North: “They’re increasing on a global basis, so basically everywhere in the world lakes are getting greener and they’re becoming more toxic. And so, there are different theories out there. One is nutrients, with the expansion of agriculture and human populations, it’s just getting more of that. And the other is climate change. One of the seminal papers on this topic is called Blooms Like it Hot. As we’re seeing these warming water temperatures, this could be resulting in these blooms.”

Consiglio: I’m Brian Consiglio, with a Spotlight on Mizzou.

Learn more about the research here

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