8 Incredible Places Where the Ocean Glows

Treehugger / Julie Bang

Beaches are beautiful at any time of day, but the night can bring something extra special. Bioluminescent tides—which shine in the darkness—exist throughout the world. Sometimes these glowing waters seem like tiny twinkling stars suspended in the ocean. Other times, they shine with extraordinary brightness.

This phosphorescence is often caused by algae suspended in the water that emits a glow whenever it is jostled either by the tide rolling in and out or by the motion of a boat, fish, or even a finger moving through the water. Sometimes the glow is made by bioluminescent organisms like firefly squid and ostracod crustaceans. In a light-polluted world, the beauty of the night can often be obscured by the glare of manmade light, but if you look closely, you might see the quiet glow of bioluminescence.

Here are eight places around the world where you can see the waters glow.

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The Blue Grotto, Malta

Bioluminescent water from inside cave at Blue Grotto, Malta

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Reachable only by a specially licensed boat, the Blue Grotto of Malta is said to be one of the most spectacular natural sights in the world. These oceanic sea caverns on the south coast are surrounded by tall cliffs that are constantly pounded by waves, producing the phosphorescent glow for which they are known.

Blue Grotto is actually just one of six caves, all of which are popular tourist destinations.

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Jervis Bay, Australia

Bioluminescence lighting up Jervis Bay at sunset

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Beyond a white sandy beach and crystal-clear water, Jervis Bay, on the south coast of New South Wales, has bright, beautiful presentations of bioluminescence. The dinoflagellate species Noctiluca scintillans, a widely occurring red tide organism, makes the sea sparkle in Jervis Bay. The most radiant displays typically occur between May and August and are especially concentrated at night after a rainfall. 

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Mosquito Bay, Puerto Rico

Boat and sunrise over bioluminescence at Mosquito Bay, Vieques, Puerto Rico

Edgar Torres / Wikimedia Commons / CC BY 3.0

One of three bioluminescent bays in Puerto Rico, the algae glow at Mosquito Bay is best observed from the water. Noted for its brilliant illumination, the bay was recognized by Guinness World Records as the brightest bioluminescent bay in 2006.

The remarkable blue glow is caused by the dinoflagellate Pyrodinium bahamense. These harmful algae produce saxitoxins that can lead to paralytic shellfish poisoning, which is highly toxic to humans.

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Matsu Islands, Taiwan

Biolumenescence along the edge of the water where it meets the land in Matsu Japan

WanRu Chen / Getty Images

The aptly named "blue tears'' of Taiwan’s Matsu Islands are caused by the dinoflagellate red Noctiluca scintillans. These sea sparkles are most visible after dark along the shores of the Matsu Islands. 

Scientists in China have begun using satellites to track the harmful plankton, which has become more abundant. The scope of the algae bloom in the East China Sea includes coastal and offshore waters, and the algae survive in warmer waters better than previously believed.

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San Diego, California

Bioluminescence on San Diego Coastline Beach at night at Swamis Beach in Encinitas, San Diego, California.

Justin Bartels / Getty Images

The dinoflagellate algae Lingulodinium polyedrum is responsible for the glow off the coast of San Diego. In the daytime, it causes the water to appear red (red tide), but after sunset, the organisms’ natural defense mechanism results in the water turning blue. The red tide in California is not associated with nutrient runoff and has not been linked to yessotoxin.  

The bioluminescent glow doesn’t happen every year, and scientists haven’t been able to predict when it will occur. But when it does happen, people flock to the beaches to see and photograph the bright blue tides.

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Toyama Bay, Japan

Large groups of firefly squid at the shore's edge in darkness in Toyama Bay, Japan

Ma-mi / Getty Images

The glow at Toyama Bay occurs for a different reason. It comes not from phytoplankton but from a phosphorescent creature called the firefly squid, or Watasenia scintillans. Every year from March to June, the bay and shoreline become inundated with millions of these three-inch squid, which come up from the depths of the ocean to breed. As they fill the waters and beaches, both fishermen and tourist operations spring into action.

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Republic of the Maldives

Beach in the Maldives with a palm tree in the next to the bioluminscent water

AtanasBozhikovNasko / Getty Images

The island paradise of the Maldives radiates just a bit brighter from mid-summer through winter when the ocean and shore glow and sparkle. The bright light is caused by ostracod crustaceans, which are bioluminescent organisms.  The warm waters surrounding these islands provide the perfect environment for these luminous organisms that can glow for more than one minute.

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Luminous Lagoon, Jamaica

Luminous Lagoon, Jamaica at night with bioluminescence showing in the foreground and city lights in the background

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This shallow fresh and saltwater lagoon glows nearly year-round in the warm waters of Jamaica. The dinoflagellates feed on the vitamin B12 produced by the mangroves that surround the lagoon, and the abundant microscopic bioluminescent plankton is illuminated by the slightest movement. Boats bring visitors to the middle of the lagoon after dark where they can swim in the radiant blue water.

View Article Sources
  1. Morquecho, Lourdes. "Pyrodinium Bahamense One The Most Significant Harmful Dinoflagellate In Mexico". Frontiers In Marine Science, vol 6, 2019. Frontiers Media SA, doi:10.3389/fmars.2019.00001

  2. Qi, Lin et al. "In Search Of Red Noctiluca Scintillans Blooms In The East China Sea". Geophysical Research Letters, vol 46, no. 11, 2019, pp. 5997-6004. American Geophysical Union (AGU), doi:10.1029/2019gl082667

  3. "Everything You Wanted To Know About Red Tides". Scripps Institution Of Oceanography.