Researchers from the U.S. Geological Survey have developed a satellite-based tool to detect harmful algal blooms (HABs) in water bodies in Idaho, including lakes and reservoirs. HABs are caused by the growth of cyanobacteria which can produce toxins harmful to humans and animals. The tool utilizes satellite images to identify the presence of cyanobacteria and chlorophyll concentrations.
Lake Lowell, a reservoir located in western United States, was chosen as a sample water body for the study. Hydrologist Tyler King, along with his team, investigated various methods for extracting information from satellite images and found that using an ensemble of different methods worked best. By combining different techniques, they were able to identify when the chlorophyll concentration exceeded 10 micrograms per liter, which is classified as a moderate risk according to the World Health Organization.
Satellites from the European Space Agency were used to collect images of Lake Lowell. The researchers aimed to be on the water body at the same time the satellite image was taken to ensure accurate detection of cyanobacteria. Prior to launching the boat, signs of cyanobacteria were already visible. Clumps of algae were observed, indicating the presence of potential harmful algal blooms.
Traditional monitoring methods for HABs are resource-intensive and have limited reach, which is why satellite-based monitoring has gained interest in recent years. While some satellites have the ability to identify cyanobacteria and blooms in large water bodies, their resolution is insufficient for smaller lakes and reservoirs. However, by utilizing different satellite image analysis methods, researchers were able to overcome these limitations and provide a more comprehensive tool for detecting HABs in Idaho’s water bodies.