The ocean is chock full of surprises, especially with strange creatures lurking in its hidden depths. Sometimes, it even glows like something out of a science fiction movie.
It’s not magic if that’s what you were thinking. Instead, it’s due to a chemical reaction called bioluminescence.
The light that comes from the ocean is powered by tiny plant-like marine organisms. When the organisms are moved by the waves or the paddle of a canoe, the light becomes visible to the human eye. They create a shimmering turquoise spectacle in shallow waters, particularly during the warmer season.
Most land and marine organisms’ bioluminescence appears as a blue-green hue. The exceptions are some land species like fireflies, beetle larvae, and even some mushrooms that have a yellow glow.
This past summer, a beautiful blue display could be seen in the North Sea between Scotland and Norway. Sunlight and warm temperatures provided the perfect conditions for phytoplankton to thrive.
According to the National Park Service, the glow was likely caused by a type of phytoplankton known as sea sparkle.
It made the water have a milky blue color in NASA satellite imagery. However, without a physical sample, scientists cannot say for sure what kind of phytoplankton it is. The bloom became visible on June 15, 2024.
Around the summer solstice, phytoplankton reach their peak numbers. They are most common in the North Sea during late spring and early summer, which is when the water is filled with plenty of nutrients. The extra nutrients are a result of increased runoff from European rivers, rain, and strong seasonal winds.
Researchers in Norway have found that the region’s phytoplankton blooms began later in the year and lasted a little longer.
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It is unclear what the cause of the delay is, but the researchers think that warmer sea surface temperatures could be contributing to the change.
The best times to view bioluminescence are in the summer and fall on dark, cloudy nights. In the United States, some of the most popular bodies of water to see bioluminescence are Tomales Bay State Park in northern California, Olympic Coast National Marine Sanctuary in Washington, the Vieques National Wildlife Refuge in Puerto Rico, and bays near Acadia National Park in Maine.
The ocean also glows in other parts of the world, such as Jervis Bay in Australia, the Matsu Islands in Taiwan, Toyama Bay in Japan, and the Luminous Lagoon in Jamaica, which glows nearly year-round.
The lagoon is surrounded by mangroves that produce vitamin B12. It sustains the dinoflagellates in the water.
The microscopic bioluminescent plankton shines with just the slightest movement. Boats often take visitors out to the middle of the lagoon after dark so they can swim in the brilliant blue water.