It's too cold for your car to start...you've lost your mailbox in a pile of snow...and your breath is turning into frost. It's time to fly away to those talcumy, white sand beaches you saw in the travel brochure. Perhaps down in Mexico or the Caribbean. Or Hawaii.
So off you go, and as your jet comes in for a landing at Pali Pali or wherever you can see the palm trees lining a gorgeous beach lapped by blue-green waters – scenes right out of the brochure. Well, almost. When you finally get your toes in the sand, it turns out to be (at best) a darker shade of pale. And a tad grainy to boot. What happened to those powdery white sands?
The fact is, some spots actually do have talcumy beaches. Like along the Caribbean coast of Mexico and around islands in the South Pacific and southern Thailand – typically, when such places run along offshore reefs (more about that later).
Experienced travelers know that brochure writers sometimes get a little carried away when it comes to describing beaches. So along reef-less resorts, the sands can be anything from light beige to golden brown. And in some places, pink, red and even black.
What causes the difference in colors? Pink beaches, such as those you'll find in Bermuda or Harbour Island in the Bahamas, get their hue from what experts say are “thousands of broken coral pieces, shells, and calcium carbonate materials left behind by foraminifera (tiny marine creatures with red and pink shells).” Got it?
Darker sands generally get their color from long-ago volcanic eruptions. The red beach on the Mediterranean island of Santorini, for example, comes from iron-rich black and red lava rocks left over from a huge blast in 1450 B.C. Over on places like Tahiti, New Zealand and Hawaii, experts trace the black beaches there to mixes of iron, titanium and the like from ancient eruptions.
You'll also find a green sand beach on Hawaii. Look on the southern tip of the Big Island and you can't miss the greenish Papakolea Beach. The hue comes from tiny olivine crystals from the surrounding lava rocks erupted by a big bang almost 50,000 years ago.
Now, about those iconic white beaches. When it comes to the powdery stuff, expert opinions are all over the place. One theory is that the sands simply drifted in from someplace else (without explaining what made the sands). Another is that the sands come from “minerals and minute shells that washed up from the ocean.”
Beyond those notions, what is fast becoming a popular explanation – and one you won't find in the travel brochures – is that white sands come from the excrement of a certain kind of fish. That's right, fish poop.
The culprit (or the benefactor, as the case may be) is the big-beaked Parrotfish. An underwater movie shot by National Geographic shows zillions of the fish munching away on tiny polyps (cousins to little jellyfish) living in the coral. Since they have large beaks, the fish also bite off small hunks of coral with their snack. They then chew up the coral and “discharge” it in plumes of waste. The plumes in turn drift up on the beach, and over time are bleached white and turned into sand by the sun. Or so that theory goes.
Dr. Jaime Capulli notes that Parrotfish have “an insatiable appetite and spend the whole day eating.” He estimates that each Parrotfish produces hundreds of pounds of coral waste a year. Multiply that by those zillions of Parrotfish noshing away on a given reef, and you can see how your gorgeous beach was created.
But don't tell the brochure writer.