Is sea sparkle an alga?
Sea sparkle is often called an alga. Biologists describe it more precisely as a heterotrophic dinoflagellate, a single-celled plankton organism that eats other plankton.
Why does sea sparkle glow?
The light reaction occurs inside the cell and starts when the water is disturbed. One cell produces a tiny point of light. If many cells gather along the high-water line or in the surf, an entire wave can glow blue.
How can you recognise sea sparkle?
During the day, a dense patch may look orange, brown or reddish on the water. In the dark, the blue glow appears only with movement. It is often visible in small breaking waves, around footsteps in wet sand or as a soft glow in shallow water.
Is it safe to swim in sea sparkle?
This website forecasts visibility and does not provide swimming-water advice. A large plankton bloom, poor visibility, strong currents or local warnings may be reasons not to swim. Always check current swimming-water information and stay on the beach if in doubt.