Algal Bloom (IMAGE) Michigan State University Caption When agricultural runoff reaches water, it can fuel blooms of cyanobacteria that can produce toxic chemicals. This satellite image shows a bloom (in green) on Lake Erie in 2017. Credit Credit: Joshua Stevens/NASA Earth Observatory Usage Restrictions none License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.