red tide

Nearshore bloom of single-cell algae called dinoflagellates; sometimes miles long, usually occurring during summer months. Red tide has nothing to do with tides, and the color it gives off isn't so much red as an unattractive brown-rust. But at night, the microorganisms, when tossed around in the foaming part of a breaking wave, produce a mesmerizing blue- green phosphorescent glow; night surfing ...