By Annie Zwerneman

Algal bloom covers a lake.

I was recently on my favorite hiking trail, which passes by a beautiful lake. But this time hiking past it, I noticed a strange, dark scum creeping along the shoreline of the water. I learned later that this scum was actually an algal bloom: a population of algae increasing quickly over a short period of time.

Some algal blooms are merely an eyesore, but others fall into a more serious category called “harmful algal blooms” (HABs): algae and cyanobacteria (formerly known as blue-green algae) that remove oxygen from the water, crowding their way along the surface and producing toxins that are harmful to animals. The toxins that HABs produce can affect peoples’ health, too.

EPA has been working to monitor HABs, including taking water samples to see where and how algal blooms may affect you. Unfortunately, taking such water samples is time-intensive, so EPA has been working alongside scientists at the National Oceanic and Atmospheric Administration (NOAA), National Aeronautics and Space Administration (NASA), and the United States Geological Survey (USGS) to find new ways to monitor the quality of inland water bodies, such as lakes and reservoirs. EPA hopes to monitor estuaries and coastal waters in the future as well.

A new Android app is being developed that displays imagery of cyanobacterial cell counts in freshwater systems, which can indicate the presence of HABs. Expected to be in beta testing this fall, the app will provide information necessary for locating and monitoring HABs. It’s primarily aimed toward stakeholders like health departments and municipalities (such as water treatment plants).

The app will display data from NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS) satellite. In the near future, EPA researchers hope to incorporate the European Space Agency’s Sentinel-3 and potentially the Landsat-8 satellite as well. They will work with their NOAA, USGS, and NASA partners to pull all these capabilities together once the app is ready for public use.

The way the app will work is a bit like the weather station. At the beginning of each week, the cell count will be updated based on the satellite information gathered the previous week. There may even be a prediction of the cell count for the upcoming week available. For example, you can get a cell count in Lake Erie for the current week, and then get a prediction of what the cell count may be next week.

Thanks to the collaborative effort of multiple federal agencies, those looking for information about freshwater quality and HABs won’t have to look far: there will be an app for that!

About the Author: Annie Zwerneman is a 2014 summer intern working for the EPA’s Office of Research and Development.