Maldives’ “Sea of Stars” is a bioluminescent plankton show, not a fixed sea

The luminous "Sea of Stars" that has drawn travellers to the Maldives is not a distinct body of water but a transient bioluminescent display produced by microscopic plankton, marine scientists say.

The shimmering, galaxy-like swirls that light up shallow water at night are caused when certain plankton emit light in response to movement or to predators. The effect can appear along different shorelines when conditions concentrate the organisms, meaning there is no single, permanent location in the Maldives where the phenomenon always occurs.

"When people say they want to see the Sea of Stars in the Maldives, they are actually asking to see a chemical reaction — it's bioluminescent plankton," Lauren Arthur, a marine biologist and wildlife presenter, told the BBC. She said the organisms can be found "anywhere in the Maldives, or even anywhere around the world where you get plankton."

Scientists have long identified dinoflagellates and other planktonic species as common sources of bioluminescence. When concentrated by currents or shallow-water conditions, these organisms can create bright, fleeting displays visible at the surface and along shorelines.

Tourists who hope to witness the effect are commonly advised to travel to islands and sandbanks where sightings have been frequent, with Vaadhoo Island among the better-known spots promoted by travel outlets. But guides and scientists stress that the appearance of the Sea of Stars is episodic. Calm, dark nights, minimal artificial light, and water that is "thick with plankton" increase the chances of seeing the glow, Arthur said.

She recommended entering the water for night snorkelling and moving about to disturb the plankton and trigger luminescence. Arthur and travel specialists also point to the Maldives’ Southwest Monsoon season, from about April to October, as a period when plankton tend to follow currents and concentrate along the northeastern side of the country, improving the odds of a sighting.

The phenomenon is not guaranteed on any given night. Factors such as water temperature, salinity, nutrient levels, tidal flow and wind-driven currents affect plankton abundance and distribution. Observers can be disappointed when concentrations are low or when sea conditions are rough; conversely, the same conditions that create dense blooms can be short-lived, producing dramatic displays that vanish in days.

Bioluminescent events of this type are recorded around the world, from coastal waters in the Indian Ocean to bays in the United Kingdom, and are not unique to the Maldives. Local tourism businesses have incorporated the spectacle into night-time excursions, but conservationists and scientists caution that increased human activity and coastal development can alter the very conditions that allow plankton blooms to form.

As interest grows, experts emphasize that responsible viewing — limiting bright lights, avoiding unnecessary disturbance of marine habitats, and following local guidance — helps protect both visitors and the ecosystems that produce the Sea of Stars. Ultimately, the glowing seascape remains a natural, fleeting reaction rather than a fixed destination, appearing where and when ocean conditions bring the right organisms together.