Pyrodinium bahamense is the one celled organism responsible and is a diflagellate. They create light when touched and glow for about 0.1 sec. It is thought to be a defense mechanism to silhouette their predators and attract larger ones! Someone in the past was bitten by a shark in the lagoon, supporting the theory! The lagoon is an ideal environment as it is very stable (wind and temperature), has slow water turnover (13.5 days for a water molecule to complete a circuit), high salinity (35-40 parts per million) and high vitamin B12 levels (thanks to the decomposition of mangrove leaves) required for the chemical reaction.