Have you heard of a red tide? A red tide is a type of “harmful algal bloom,” an occurrence that has been reported in every coastal state in the United States. Microscopic algae occur naturally in small numbers in all bodies of water. Harmful algal blooms occur when these algae undergo a rapid growth period that may become toxic and harm animals, people, and the environment in which the bloom is occurring. Climate change and nutrient runoff may be increasing the frequency of these events. Resources to monitor where and when harmful algal blooms may be occurring are limited.
A new mobile app (currently only for Android users and available through the EPA or Google Play) from the multi-agency Cyanobacteria Assessment Network (CyAN) will use satellite technology through NASA to alert officials when a harmful algal bloom may be forming. CyAN also includes the Environmental Protection Agency, U.S. Geological Survey, and the National Oceanic and Atmospheric Administration. In a press release from NASA, Goddard Space Flight Center lead for CyAN Jeremy Werdell stated, “resources are limited, and it’s not possible for everyone on the ground to be monitoring all inland water bodies all of the time. Satellites are providing a tool to help inform how and when to expend resources to go and collect water samples.”
Although harmful algal blooms consist of microscopic algae, large aggregations appear as large green patches from space. Algal blooms also emit fluorescence, which helps satellites detect their presence. NASA/USGS Landsat satellites, the European Space Agency’s Copernicus Senteinel-2 and Copernicus Senteinel-3, and a few other satellites feature instrumentation to detect the presence of algae and relay that information to NASA supercomputers. NASA computers then create weekly reports detailing algal conditions in more than 2,000 lakes throughout the United States. If a lake is bloom free, it will appear green on the mobile app. Yellow will indicate that algae are present, and red will indicate that a bloom is present.
In addition to aiding water quality officials, this new app may be useful to the public seeking recreational areas. Donalea Dinsmore from the Wisconsin Department of Natural Resources told NASA “each summer, the department receives questions about whether the green muck floating on lakes is harmful, or reports of dogs sickened after swimming in or drinking from a lake.”