Ocean waves north of San Diego look quite a bit bluer than usual this week. Beginning Monday, a 20-mile stretch of California coastline from Encinitas to La Jolla took on what CNN calls an "electric blue glow" as tiny bioluminescent creatures moved in. Despite sharing his own photos with NPR, a professional photographer says "no photo can really do it justice," adding the glow was "much less vibrant" but "still beautiful" as of Tuesday night.
Scientists credit a bloom of dinoflagellates, also known as a red tide. The microorganisms give the water a reddish hue in daylight, but at night, they appear to glow as they're disturbed by waves. NPR reports huge crowds have been flocking to witness the phenomenon, which scientists have been observing for decades. It's unclear how long it will be visible. Red tides have previously lasted a few days to beyond a month. (Read more strange stuff stories.)