Monday December 6, 2021
Algae form the basis for many aquatic food webs, but when certain algae, bacteria, or other tiny photosynthetic organisms start to grow out of control—a phenomenon called an algal bloom—they can cause major problems. Harmful algal blooms (HABs) disrupt ecosystems, negatively affect drinking water supplies, and threaten human health worldwide, costing an estimated $4 billion per year in the United States alone, said Tyler King, a hydrologist at the U.S. Geological Survey’s (USGS) Idaho Water Science Center.
Because of the sheer scale of the problem, HABs are difficult to monitor from the ground, so scientists are working on ways to more effectively monitor them from space. Currently, scientists, including those at the U.S. interagency Cyanobacteria Assessment Network (CyAN) project, are working on using satellite images to identify and monitor the spread of algal blooms that involve cyanobacteria, which can be particularly problematic.
But there are many, many types of microbes associated with HABs—even the term cyanobacteria encompasses thousands of species—and available technology isn’t very good at telling them apart using satellite data. This is important because although many species are relatively benign (at least in terms of danger to human health), blooms of certain species produce potent toxins that affect the nervous system or liver. Determining whether a bloom is made up of these dangerous species is a key part of creating an effective management plan to protect people from the negative effects of the bloom.