Pic o’ the week: Bioluminescent Beach

Will Ho is among those lucky enough to witness a beach aglow in nature’s own neon. While honeymooning in the Maldives, he saw this beach glittering with … yes, ostracod crustaceans.

Photo copyright Will Ho
By the Dusit Thani resort, Mudhdhoo, Baa Atoll, Maldives. Photo copyright Will Ho.

These entrancing photos have spread across the web, with one scientific misunderstanding. This is not bioluminescent phytoplankton, biology professor Jim Morin of Cornell’s Department of Ecology & Evolutionary Biology, has clarified, but instead is an instance of an amazing mortality event of crustaceans in the Indian Ocean:

“These are tiny crustaceans. They produce these mass mortalities commonly in the Maldives. The species in question is almost certainly Cypridina [=Pyrocypris] dentata, a widespread cypridinid ostracod in the Indian Ocean [and perhaps all the way to the Chinese coast, where they are known as “blue tears”]. There are numerous reports from the Indian coast, especially the west side, and up into the Arabian Sea, in addition to the Laccadives and the Maldives. However, because luminescent bays in the Caribbean and crashing blue waves everywhere in the world are well known, and are usually caused by luminescence from dinoflagellates [which ARE a kind of phytoplankton], there is much confusion about the cause of these “starlit beaches.” But they are clearly NOT dinoflagellates; they are ostracod crustaceans that secrete cypridinid luciferin and luciferase from glands on their upper lips so that the luminescence is external [not intracellular as in dinos]. Furthermore the luminescence is discrete as fairly large spots, not diffuse as with light from millions of dinos. Ostracod light can last many seconds, even minutes, which is not what happens with dinos.”

George Percy noted on Flickr that he remembers these from his childhood in India:

“I am from India … and I used to see them all the time at night on the Marina Beach in Chennai. My friends and I used to scoop them up and hold it in our hands for about 10 seconds and they will lose their luminescence.”

Pic o’ the week – sand grain kaleidoscope

Ah! If I had the eyes to see,
And brain to understand,
I think Life’s mystery might be
Solved in this grain of sand.
 –Robert William Service

Here, a microphotograph by Dr. Gary Greenberg of sand, that stuff the we love to get between our toes on the beach.

Greenberg’s passion is revealing the ‘secret beauty of nature’ by photographing elements of the natural world through the lenses of the hi-def, 3-D light microscopes that he invented.These sand grains are from a Maui beach. As Dr. Greenberg notes:

“The tip of a spiral shell has broken off and become a grain of sand. After being repeatedly tumbled by action of the surf this spiral sand grain has become opalescent in character. It is surrounded by bits of coral, shell, and volcanic material.”

His stunning photos of sand from around the world are collected in his book A Grain of Sand. Check it out.

Sea turtle hatchlings LOVE beach resort lights

There’s bound to be messiness when creatures who’ve roamed the seas and beaches for millions of years face the relatively newfangled phenomenon of artifical light. Scientists believe that sea turtle hatchlings, when they emerge from their shells on beaches around the world, institnctually move in the direction where the sky is brightest. On a beach with no artificial lights, that direction is most often the open horizon of the sea.

Here, a few people from the group SeaTurtle Oversight Protection in Ft. Lauderdale, Florida took a night camera out on the beach as they tried to re-direct scores of hatchlings who scurried relentlessly toward the resort lights on a beach… even when they were put in the lapping waves of the ocean instead.

Citizen reporting giving us an interesting visual view of light pollution (and, further into the video, beach chair hazards) and turtle nesting – not meshing well together.

* See Andrew Revkin’s NY Times Dot Earth post about this post & STOP’s video: On Florida Beaches, Let There Be Dark