Fish Hoek resident and photographer, Robyn Gwilt, took this photo of a red tide on Fish Hoek beach on Tuesday October 23. The water is transformed in to a magical blue glow known as bioluminescence. Red tide is a common name for a worldwide phenomenon known as an algae bloom and is caused by large concentrations of aquatic microorganisms. Bioluminescence is the production and emission of light by a living organism and occurs widely in marine vertebrates and invertebrates, as well as in some fungi, microorganisms and terrestrial invertebrates such as fireflies. Movement, such as waves breaking, activates the effect.