Algal bloom in Lake Erie, satellite image. Algal blooms are formed by the rapid multiplying of phytoplankton, microscopic marine plants that drift on or near the surface of the sea, sustained by sunlight. Lake Erie is one of the Great Lakes and is located on the border between Canada and the USA. Algae in this lake thrive when there is an abundance of nutrients (many from agricultural runoff) and sunlight, as well as warm water temperatures. Image data obtained on 28 July 2015, by the Operational Land Imager (OLI) on the Landsat 8 satellite |