Sea Monsters: That Sparkling Tide

The First Mate knows I have a bit of a thing for bioluminescent sea creatures. They seem to have a thing for me, as well, since they coincidently pop up not only in my research but also in daily family life. My younger daughter recently wrote a short story in her creative writing class about a misfit octopus who glows purple instead of the requisite green emitted by her family and friends. My older daughter knits sea creatures as a cottage industry and one of her best sellers is the angler fish. The Brethren will recall that these interesting ladies (all the ones with anglers are ladies) dangle a glowing ball of bacteria-laden gunk just in front of their gaping jaws to lure their prey. Of course it goes without saying that the glow of more than one school of plankton has dazzled the eye of pirate, privateer and navy man alike.


Thus it was no surprise that the First Mate sent me this piece from the New York Times. Entitled “The Brightest of Creatures,” it is a review of the newly opened exhibition at the American Museum of Natural History called “Creatures of Light” (find their website here). When I read the article my attention was drawn not to the snark about “manufactured” displays but to the information about the specific plankton known as dinoflagellates. These unusual organisms are the cause of what is known as bioluminescent bays, a phenomenon that is not as uncommon as the circumstances required to produce it might suggest.

There are 18 types of dinoflagellates that can emit the blue-green light seen in the eerie photo at the header. They must be “mechanically stimulated” to do so, by natural tide or waves, the wakes of ships or boats, or even by an animal swimming through them. The phenomena can occur only under conditions described in the article:

The bay must have a narrow opening to the sea, with gentle winds that push waves of dinoflagellates into the bay. Sunlight must be plentiful. And shallow water. And mangrove roots and leaves to provide nutrients. Then all of this must be accompanied by dinoflagellates, which are far older than the dinosaurs, dating back 1.2 billion years.

One less cheerful point does surface; the article also notes, “… some are poisonous, others simply delightful.” If you image search “bioluminescent bays” you will see a number of pictures of people in the water, creating the blue-green glow like they were making angels in the snow. This may be ill-advised given the potential consequences of anaphylactic shock; perhaps it’s best to ask a knowledgeable local before diving in.

Needless to say the conditions that make a bioluminescent bay possible are available in high concentration around the landforms of the Caribbean and the Gulf of Mexico. Doubtless our seafaring ancestors marveled at these amazing light shows, and wondered at their cause. What a wonderful addition to any seafaring story to have our hero peering through his glass to espy a prize at anchor in the faint neon-green glow. That’s good atmosphere, especially if there are paranormal critters involved.

Header: Bioluminescent bay via Amazing Stuff UK