True colour image of a red tide algal bloom along the southwestern coastline of Florida, USA. High concentrations of the algae Karenia brevis were located along the Lee County and Collier County shorelines. In-water measurements revealed more than 1 million cells of the algae per litre of water, a level at which the organism becomes highly toxic to fish and shellfish. Image acquired by the Moderate-resolution Imaging Spectroradiometer (MODIS) flying aboard NASA's Terra satellite, on 17 February 2002.