Bioluminescence Lights Up San Diego Tide

Off the coast of San Diego, microscopic phytoplankton called dinoflagellates are putting on an amazing display of bioluminescence. Scientists at Scripps Institution of Oceanography at UC San Diego are taking samples from this red tide, which happens when phytoplankton aggregates.

The phytoplankton, Ceratium falcatiforme, and Lingulodinium polyedra, glow in response to movement in the water. The microbes swim toward the surface of the water during the day, creating a thin layer on the surface. During the day, it makes the water look red and at night, it glows blue.

The phytoplankton are not thought to be harmful, but some people may experience a reaction if they are exposed. Scripps scientists are studying them to try to learn more about red tides, which are very unpredictable.