It could be the grim denouement from a science fiction film, as the silhouette of a man solemnly watches a glowing sea, with a child perched atop his shoulders.
But this is not cinema trickery – it’s a natural phenomena caused by a chemical reaction called bioluminescence, which happens when a naturally-occurring micro-organism in the water is disturbed, causing a chemical reaction which emits light.
The reaction is similar to the ‘glow’ that fireflies use to attract prey or mates. Many undersea organisms ‘glow’, especially creatures that live at depths where light from the surface is less likely to penetrate.
The spellbinding sight was captured at Moonlight Beach in Encinitas, California, yesterday. The night-time glow is a side-effect of blooming red algae, known as red tide, which can turn entire beaches scarlet and murky during the day.
The smell of decay, caused by rotting kelp, plankton and fish often accompanies the event as the red algae starves the water of oxygen and light. By night, there is an increase in microscopic plankton called dynoflagellates, which glow in the dark when disturbed by currents or waves.