Coral reefs, which are found in the clear and shallow waters of tropical oceans worldwide, are among the most diverse and productive communities on earth.  But for years scientist have been alarmed by signs that these ecosystems are endangered.  Now a new study published in the Smithsonian journal should help allay these fears.  Scientists from the University of Miami spent three years examining some twenty coral reef areas in the Western Atlantic, and found, contrary to expectations, many of these reefs had 26 percent living coral cover.  This is considered healthy, and comfortably above the 15 percent coral cover other studies revealed.  No doubt this is splashing good news for ocean enthusiasts!