Tracking Blooms from the Sky

By Kacey Fitzpatrick

Image of a map created with the new app.

Water quality managers can drop location pins in their water bodies of interest and the pins change colors depending on user settings.

With help from partners, EPA is going above and beyond the agency’s traditional methods of monitoring harmful algal blooms in water. EPA has joined NASA, NOAA, and the U.S. Geological Survey (USGS) to use satellite data to monitor algal blooms and develop an early warning indicator system for toxic and nuisance blooms.

Algal blooms have caused extensive problems in lakes worldwide. We saw this in August, 2014 when half a million people living in and around Toledo, Ohio were issued a water advisory alerting them to avoid all contact with Toledo drinking water after a harmful algal bloom of cyanobateria in Lake Erie had produced unsafe levels of the toxin microcystin.

Blooms like these are becoming a more frequent occurrence and are having greater impacts than ever before. The estimated annual cost of U.S. freshwater degraded by harmful algal blooms is $64 million in additional drinking water treatment, loss of recreational water usage, and decline in waterfront real estate values.

The new multi-agency effort will build on previous NASA ocean satellite sensor technologies created to study the global ocean’s microscopic algal communities. EPA researchers will provide the science that links the current and historical satellite data on cyanobacteria algal blooms provided by NASA, NOAA, and USGS to monitor changes in the environment, assess economic impacts, and protect human health.

The first step in the five-year project will be creating a reliable, standard method for identifying cyanobacteria blooms in U.S. freshwater lakes and reservoirs using ocean color satellite data. NOAA and NASA have lead the way in using oceanic satellite data for monitoring and forecasting harmful algal blooms and EPA is integrating this data into the decision-making process.

Researchers will also conduct a large-scale investigation of potential causes of harmful algal blooms in U.S. freshwater systems. Blooms in lakes and estuaries result from aquatic plants receiving a combination of excess nutrients, perhaps from river runoff, and other environmental conditions such as temperature and light. Various land uses, such as urbanization or modernized agricultural practices, influence the amount of sediment and nutrients delivered in watersheds, which can influence cyanobacterial growth.

This innovative use of satellite data to monitor and report blooms throughout a region or state will help with management of events and significantly reduce risk to the public. Ultimately, this project will reduce the amount of resources needed to protect human health and the environment.

About the Author: Science writer and student contractor Kacey Fitzpatrick is a frequent contributor to It All Starts with Science.



Editor's Note: The views expressed here are intended to explain EPA policy. They do not change anyone's rights or obligations. You may share this post. However, please do not change the title or the content, or remove EPA’s identity as the author. If you do make substantive changes, please do not attribute the edited title or content to EPA or the author.

EPA's official web site is Some links on this page may redirect users from the EPA website to specific content on a non-EPA, third-party site. In doing so, EPA is directing you only to the specific content referenced at the time of publication, not to any other content that may appear on the same webpage or elsewhere on the third-party site, or be added at a later date.

EPA is providing this link for informational purposes only. EPA cannot attest to the accuracy of non-EPA information provided by any third-party sites or any other linked site. EPA does not endorse any non-government websites, companies, internet applications or any policies or information expressed therein.