Among the natural wonders of the Okinawa Islandsin the far southwest of Japan, we can find some beaches with a unique feature, which the Japanese call Hoshizuna no Hamaliterally “star shaped sand”. In fact, these beaches are formed by tiny “grains” star-shaped and for several years they have been characterized as a famous tourist destination in some islands of Okinawa prefecture, such as those of Taketomi, HatomaAnd Iriomote. Although, at first glance, the “sand” of these beaches may seem the same as all the rest of the planet, upon closer and more careful analysis, hundreds of thousands of tiny five or six pointed “stars” of the size of just a few millimetres. It is therefore not real sand, that is, made up of mineral sediments well distinct from each other, generally ranging in size from 2 to 0.06 millimetres. The small stars on Japanese beaches are in truth nothing other than the exoskeletons of tiny organisms marine belonging to the class of foraminifera. In particular, this star shape is associated with the species Baculogypsin sphaerulatawhich uses the spikes of its exoskeleton to calcium carbonate to attach themselves to the algae of ocean vegetation. At the end of the life cycle of these organisms, the exoskeleton, now empty, is transported by sea currents and tides and deposited on the beaches of the mainland, where it accumulates giving rise to the Hoshizuna no Hama.
On Taketomi Island a legend popular tells the origins of these curious beaches. Tradition has it that the little stars are actually the descendants of the Star Polar and of Cross of the Southfallen into the seas of Japan and devoured by a large sea serpent. The skeletons, now empty, of these poor entities would then accumulate over time on the beaches of the archipelago.
The Okinawa Islands are located in southwest Japan and are characterized by a warm subtropical climate influenced by monsoons. The region, in addition to being of particular scientific and environmental interest due to the phenomenon we talked about in this article, is literally a paradise for anyone who loves the sea, tropical forests, quiet beaches and even “starry” ones. The best time to visit these curious beaches is during the low tidewhen the small star-shaped exoskeletons are most visible.
