Eerie blue glow illuminates Washington coastline, photos show. What caused it?

A photographer captured an eerie blue light glowing on the waves of the Washington coast, photos show.

Matt Nichols also caught a video showing how the light reflected off the whitecaps of the waves. He posted the photos and video in the PNW Bioluminescence Facebook group.

“I am excited to announce that bioluminescent season has begun!” Nichols wrote. “After all of these nice weather days, I had a hunch that it might be here, and sure enough, I found vibrant blue glowing waves … Hoping this is the start of a very active bioluminescent season!”

Nichols took the photos Sunday morning at Kalaloch Beach 4 in Forks, he told McClatchy News. He said the glow is called “bioluminescence,” which is “the emission of light by a living organism,” according to Discovery Sea Kayaks on San Juan Island.

The bioluminescent organism that causes the blue glow near San Juan Island “is a marine dinoflagellate … called Noctiluca,” the company said.

Nichols said the glow he saw is likely also from dinoflagellate algae.

“I believe that it could reach as far as the Puget Sound, but the light pollution there may hinder the experience,” Nichols said. “The algae thrive in warmer, calm conditions, which is why I expected them to be present after this record streak of clear, warm days.”

According to the National Ocean Service, “typically bioluminescence is used to warn or evade predators, to lure or detect prey and for communication between members of the same species.”

Nichols first encountered the phenomenon last summer at Ruby Beach in Olympic National Park while taking photos of the stars.

“I tried over and over to find them again and eventually learned what conditions are necessary for them to be visible,” he told McClatchy.

To see bioluminescence on the waves of the Washington coast, there must be little to no light pollution, Nichols said. The best time to look is during a new moon or “once the moon has set, in the darkest part of the night.”