A pretty enough lagoon by day, the Glistening Waters at night is an eerie, ethereal experience.
Any agitation to the still, black water produces a strange and beautiful blue-green light. Boats leave shimmering waves in their wake, fish dart by like little neon lanterns and swimmers paint the water with glowing trails. The ghostly glow comes from an abundant population of microscopic dinoflagellates that thrive in the brackish lagoon, and Glistening Waters is one of only a handful of places in the world where these bioluminescent organisms can be observed and studied year-round.
Dinoflagellates can be found in all the world’s oceans, occasionally in high concentrations, but these sudden surges of population are hard to predict and generally don’t last long. The unicellular organism requires a very specific set of conditions to survive in, and it is an extremely rare and fragile ecosystem that can support them permanently. Generally no more than eight feet deep, Glistening Waters is formed where the fresh waters of the Martha Brae River combine with the Caribbean’s saltwater, creating a warm, shallow, brackish environment that is ideal for the dinoflagellates.
Vitamin B12 is another key element to their successful growth, and the red mangrove trees which line the water provide plenty for the dinoflagellates to feed on. Bioluminescence occurs as a chemical reaction within the organism when excited or disturbed by movement. It is thought that the flashes of light are a defense mechanism, meant to startle potential predators or even attract those higher up on the food chain to prey on the smaller aquatic life that feeds on dinoflagellates. Following a circadian rhythm, the bioluminescence occurs only at night which allows the dinoflagellates to essentially recharge during the day. The more sunshine the lagoon receives during the day the brighter the organisms will glow at night, so it’s best not to visit following a rainy day or during a full moon.
Bioluminescence is a fascinating phenomenon that is still not fully understood, and scientists from around the world have been drawn to Glistening Waters because it offers ideal conditions for studying dinoflagellates. As for the tourists, if the natural beauty isn’t enough of a lure, Jamaican folklore has deemed the luminous lagoon a sort of fountain of youth. Legend has it that women who swim in the mineral-rich waters become more beautiful and look younger, while men supposedly benefit from an increase in penis size and new levels of virility.