A somewhat blurry photo of a beach at night, clearly some kind of alcoholic beverage in the hands of at least two of the people, one of whom seems be in a state of some excitement, the other two staring intently at – the sand. What is the story behind this strange image?
I described a while ago the wonderful pink sand beach on Komodo Island, as we experienced it during the day. Returning at night for a beach barbecue, we would find that it had another surprise in store for us. The excited person in the photo is François, a delightful Swiss fellow traveller with whom, together with his wife, Ursula, we shared many enjoyably garbled bilingual conversations during our trip (well, garbled on our part). That evening we were loitering about enjoying the place, the wine and the company, when we heard an excited exclamation from François who seemed to be performing some kind of bizarre dance, stomping in the sand and pointing at his feet (while, of course, cleverly maintaining the stability of his beverage). Deciding to humour him, we wandered over – to find that his stomping was producing endless flashes of brilliant blue light amongst the sand grains.
The result was a whole crazy group of people leaping around, stamping on the sand and shouting in delight – bioluminescence! Not the easiest phenomenon to photograph, but François just sent me this image, which I have adjusted slightly so that the sand grains are visible for scale:
My (not particularly well-informed) guess is that we were witnessing bioluminescent dinoflagellates, single-celled marine plankton whose name derives, dramatically and bilingually, from the Greek for “whirling” and the Latin for “whip,” reflecting aspects of their morphology. Many of them are – like the majority of marine organisms – capable of bioluminescence, mostly of this iridescent blue colour, and it was some of these critters whom the waves were bringing in that evening and providing our light show in the sand. Their individual displays were brief, only slightly more than a flash, and induced by the agitation of our pounding of the sand – apparently it is the deformation of the cell that triggers the chemical reaction. Bioluminescence is an extraordinary phenomenon, “generated by an enzyme-catalyzed chemoluminescence reaction, wherein the pigment luciferin is oxidised by the enzyme luciferase… Most marine light-emission belongs in the blue and green light spectrum, the wavelengths that can transmit through the seawater most easily.” (Sciencedaily). It seems likely that dinoflagellates use bioluminescence as a deterrent and warning mechanism, but the phenomonenon is not well understood and is the subject of extensive research - for a comprehensive resource, see http://www.lifesci.ucsb.edu/~biolum/ from the University of California, Santa Barbara. And here's a great science fair project outline on bioluminescence, with all kinds of further resources.
The illustration above is from a blog piece by Marko Manriquez, where, fascinatingly, he is proposing an art installation using bioluminescent dinoflagellates; interestingly, I found this at the same time as discovering that the Smithsonian Natural History Museum is currently holding a special exhibition inspired by bioluminescence:“The Bright Beneath: The Luminous Art of Shih Chieh Huang.” The art is inspired by our friends such as the dinoflagellates, but sadly does not feature any of the critters themselves as far as I can tell – but it makes me wish I was in Washington.
I shall end by noting that strange bioluminescent phenomena were on display in other ways that night on Komodo’s pink beach – note the dazzling effects on the head of the old guy next to François in this photograph:
François, many thanks for your discovery, your dance, your photo – and your company.
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