A Dive Into the Deep Blue-Green Sea—Steven W. Wilhelm, PhD—Aquatic Microbial Ecology Research Lab, University of Tennessee

Kenneth & Blaire Mossman Professor of Microbiology, Steven W. Wilhelm, joins the show to talk about cyanobacteria, the problems presented by blue-green algae blooms, and the research he's conducting in the lab. In this episode, you'll learn:

• What the difference is between a blue-green algal bloom and a "dead zone"
• Why the switch from ammonium nitrate to urea as fertilizer about 25 years ago coincided with blue-green algal bloom issues
• In what ways toxic algal blooms are detrimental to humans and other species

Cyanobacteria is responsible for carrying out more than 25% of the photosynthesis on the planet, which means that about one out of every four breaths of oxygen you take is thanks to these single-celled bacteria that can be found in abundance in every aquatic system in the world. But what happens when there's too much growth of cyanobacteria, and what causes overgrowth?

Wilhelm explains that concerning algal blooms are driven primarily by human activity—specifically those activities which result in high levels of nutrients such as nitrogen and phosphorus being pumped into the environment and contributing to rapid population increases in cyanobacteria. When this happens, the algal blooms that form fundamentally change the water systems they are in by pushing out algae that may be better fish food, and producing toxins called microcystin and other compounds which can be harmful to other species, including humans. When these blooms die, they become food for heterotrophic bacteria that consume oxygen. As a result of this, "dead zones" form, which have significant impacts on fish habitat and other forms of aquatic life.

So, what can be done about this problem? Wilhelm and the team at his lab spend a lot of time sequencing RNA and DNA in order to investigate why different organisms emerge under different circumstances. The hope is that with a better understanding of why cyanotoxins do so well under certain conditions (as opposed to more beneficial algae), it will be possible to intervene with a treatment or other method and prevent or limit further growth.

Tune in for all the details and visit http://wilhelmlab.utk.edu/ to learn more. Available on Apple Podcasts: apple.co/2Os0myK