‘Sea Sparkle’: Rare Bioluminescence Lights Up the Waves at Irish Beach

Courtesy of Joleen Cronin

A beach in Ireland transformed into a breathtaking rare spectacle as bioluminescent plankton colored the incoming waves a sparkling electric blue.

One beachgoer, a photographer, caught the magical natural phenomenon on camera.

Joleen Cronin took her camera to Fountainstown Beach, south of Cork City, close to midnight on Aug. 16 after reading a social media post about the rare event.

Courtesy of Joleen Cronin

“It was amazing,” Cronin told the BBC.

“When you put your feet in the water it would just kind of explode beneath you,” she described. “We went paddle boarding, and when the paddle hit the waves, it was like a disco.”

Cronin has been swimming in bioluminescent waters before, she said, but had never witnessed a show of such profusion and intensity.

Photographer Joleen Cronin. Courtesy of Joleen Cronin

Bioluminescence is the name given to the emission of light by marine organisms such as bacteria, algae, jellyfish, and plankton. It can occur in ocean waters of any depth; however, it creates a particularly surreal spectacle when it happens in the shallows.

Warmer weather heats large bodies of water, giving the marine organisms the energy they need to glow even brighter, hence the abundant summertime display at Fountainstown Beach.

Before long, the sands were populated by an additional 15 to 20 people, Cronin told RTÉ’s News at One, a program by Ireland’s National Public Service Broadcaster. She said all of these people had read the same social media post and hoped to enjoy the rare sight of the electric-blue waves rolling in.

Courtesy of Joleen Cronin

“It is something that I have never, ever witnessed. I was just completely blown away and mesmerized by the whole thing, to be honest,” Cronin told the Irish news outlet.

“[L]iterally when you put your head in the water and you saw all that sparkle come in front of you, the beauty of it was just mind-blowing,” she said.

Cronin later shared a series of photographs on Facebook.

“Yep, it’s a Sea Disco and this is not photoshop,” she wrote. “The intensity was incredible, each wave splashing millions of sparkles on the beach. Wow, wow, wow! Nature is so incredible.”

Courtesy of Joleen Cronin

Fountainstown Beach is well known for bioluminescence. With pristine waters and not much shipping traffic sailing through, the natural spectacle can flourish undisturbed. Some local companies have even found lucrative ways to embrace this unique attraction.

Jim Kennedy of local kayaking company Atlantic Sea Kayaking said in the report by BBC that he and his colleagues have been running nighttime kayaking trips for 30 years.

“We’ve had magazines come out with us from around the world,” Kennedy said, adding that Cronin’s spectacular photographs are “right up there with them. The only time I’ve seen photos like those taken this week is in the National Geographic.”

Courtesy of Joleen Cronin

According to Ocean Research and Conservation Ireland, in Irish waters, bioluminescence is caused by the single-celled dinoflagellate called Noctiluca scintillans, more commonly known as “sea sparkle.”

Bioluminescence occurs in oceans worldwide and can vary in color from blue to red. Its function is not entirely understood, according to the National Ocean Service, although marine biologists claim that “sea sparkle” is typically used to warn or evade predators, to lure prey, or for different members of the same species to communicate.

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