hey, mike: Star sand

While I was emptying my boots of sand after filling sandbags at work I noticed that some of the sand seemed different—shaped like tiny stars. Is this sand native to Okinawa? Are there beaches filled with this kind of sand?

— Reggie Valdez

Grains of sand, like many other aspects of the environment, are often taken for granted until you’re given an opportunity to take a closer look. While sand collecting in the bottom of your boots can be irritating (not to mention the particles that get into cars, beds, sandwiches, and Speedo LZR Racers), some sand can actually be quite beautiful when studied closely. Sand can be made of many different materials: from the Hawaiian black sand of volcanic origin, to brilliant quartz sand, to sand made up of particles of coral, sea urchin spines, and other sea organisms. Incidentally, the sand in your boots was probably star sand, or hoshi-zuna.

On the Southern Ryukyu Island of Taketomi, located between the Ishigaki and Iriomote Islands, a folk story told by Toru Uesedo insists that star sand are all that remains of the children of the North Star and Southern Cross—infant stars that were born in the warm, gentle currents of the seas surrounding the island. In their parental bliss, the Southern Cross and the North Star had regrettably forgotten to garner the sea god’s permission to use the area. In a fit of petty anger, the temperamental deity had the celestial offspring dispatched. After the conflagration, the tiny skeletons of the stars washing up on the shores of Taketomi island were all that remained. Fortunately for the infant stars, a kind goddess lived on the beaches of the beautiful island. She took pity on the star children and gently gathered their remains. She instructed all of her followers to place the star sand in their incense burners so that the sand could follow the smoke back to their parents in the heavens. Many islanders still follow this custom today.

All legends aside, scientists state that star sand is actually made up of the exoskeletons (shells), of millions of aquatic creatures called foraminifera. These infinitesimal organisms are among the smallest of the marine protozoa—a kind of minuscule amoeba with a tiny shell. Foraminifera are found in most marine environments, from the relatively shallow inter-tidal regions to the deepest ocean trenches, from the tropics to the poles. Foraminifera are a vital link in the world’s marine food chain. On any given continental shelf there can be tens of thousands of living creatures per square meter of ocean bottom. And, many larger animals such as snails, sand dollars, fish and others depend on foraminifera for sustenance.

Although plentiful in the oceans, star sand is rare, especially on mainland Okinawa. It is sometimes sold in tiny jars to tourists because the sand almost universally brings fond feelings for the islands’ beautiful beaches. In other words, don’t throw away the contents of your boots; while they may not be baby stars with celestial parents, you never know...

—Mike Daley

Got questions for Mike? E-mail editor@okinawa.usmc-mccs.org.