Coral Reefs Postcard Stamps

Value:  51¢ Postcard rate non-denominatedIssue Date:  March 29, 2019First Day City:  St. Louis, MOType of Stamp:  DefinitivePrinted by:  Ashton Potter (USA)Printing Method:  Offset, MicroprintFormat:  Pane of 20Found in the clear shallow waters of the Caribbean, elkhorn coral form fast-growing colonies that are home to a variety of marine life.As its name suggests, elkhorn coral resembles elk antlers, with a structure of several complex branches.  It grows quickly – up to five inches per year, reaching 12 feet in diameter and six feet tall.  Its yellow or brownish color comes from the zooxanthellae algae that lives inside its tissue.  This algae uses photosynthesis to supply the coral with nutrients.  Elkhorn also feed on plankton it captures in its tentacles.  In turn, elkhorn coral are home to a variety of creatures including lobsters, parrotfish, and shrimp.Elkhorn coral has been declared an endangered species.  It was once plentiful, but an outbreak of white band disease in the 1980s reduced the population by 97 percent.  Several other threats have hurt the elkhorn population, including coral bleaching (loss of the algae in its tissue), climate change, and storm damage.  This affects only only the coral, but the creatures that depend on it to survive.Attempts have been made to help recover the elkhorn coral’s numbers, with some success.  One advantage they have is that broken antlers can attach themselves to the ground to form new colonies, helping the elkhorn to slowly recover on its own.