How Old Are the Oldest Coral Reefs?

How old are the oldest coral reefs? When you consider the fact that coral is one of the longest lived organisms on the planet, it stands to reason that the oldest coral reefs are going to be pretty old. The oldest coral reefs known are an estimated 4,265 years old.

According to a 2009 article available on Live Science.com, the oldest coral reefs in the world that have been discovered so far, have been found in Hawaii. The coral reefs that have been found in Hawaii and that are believed to be the oldest coral reefs are an estimated 4,265 years old. 

Coral has been called the oldest living organism with a skeleton on the planet. However, while coral technically meets the definition of having a skeleton, it is more of an exoskeleton that the coral builds on, grows on, dies on, and then reproduces on.  This means you can think of coral as more like a vine growing on a tree.  When the tree dies, new vines might still sprout but the old parts of the tree are still considered to be as old as the tree is. This means that even if the currently growing, living parts are not the original parts from 4,265 years ago, the age is still determined based on the oldest parts.

So, while the coral may have been developing and growing in that spot for 4,265 years, it is possible and actually quite probable that most of the coral in that reef is not actually a full 4,265 years old.  It is hard to say whether any of the coral in that reef has actually been developing for 4,265 years, and it may take years of dedicated study by biologists and other scientists to determine whether or not this is the case.