A major red tide event occurred in waters off Southern California in the spring of 2020, resulting in dazzling displays of bioluminescence along the coast. The spectacle was caused by exceedingly high densities of Lingulodinium polyedra (L. polyedra), a plankton species renowned for its ability to emit a neon blue glow. While the red tide captured the public's attention and made global headlines, the event was also a harmful algal bloom.
