Sand: A Grain of History

When people think of sand, usually the first thing that comes to mind is a sandy beach.  Sand is the pulverized, weather rock including some fragments of tiny shelled creatures, which are tossed up by the waves and are also sediment from other inland areas.  Sand is basically the breakdown of rocks.  Some minerals are very unstable and decompose, while other minerals are much more stable.  The minerals that are more stable tend to get left behind.  All of the variables come together to create different-looking beaches.  Sand has been around for a long time, so most of the sand that is on the beaches, especially on the East coast and the Gulf coast, are about 5,000 years old.  Sand doesn't reach beaches today like it used to, so most of the sand is old.  One reason is the general rise in sea levels.  The rise in sea levels over the last 12,000 years has flooded river valleys and created large estuaries.  The estuaries trap the sand that would of reached the coast and gone onto the beaches, but instead stays trapped in the estuaries.  After major storms, beaches have to be replenished, by having sand off-shore be dragged up to the beaches.
There are so many grains of sand in the world, more than anyone could ever imagine.  With all this sand, where could it possibly come from?  Well, a lot of this sand is poop.  Key players in regulating algae and reef life is the Parrotfish.  The Parrotfish have additional teeth in their throats to help break down all the coral they eat into sand.  Parrotfish don't even have stomachs, so when they digest the sand, in comes right out exploding into a cloud of sand.  840 pounds of sand can be created alone by a larger parrotfish.  Besides the parrotfish; worms, sponges, and oysters also produce sand in the Pacific ocean, but no animal can do it as well as the parrotfish.  Sand has a very interesting history.